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Yu Sang, Huimin Sun, Chao Li, Lihua Yin
Published: 25 July 2021
Neurocomputing, Volume 446, pp 204-210; doi:10.1016/j.neucom.2020.09.087

Abstract:
Recently accumulated massive amounts of geo-tagged photos provide an excellent opportunity to understand human behaviors and can be used for personalized POI recommendation. However, no existing work has considered both the visual contents in these photos and the sequential patterns of users’ check-ins for POI recommendation. To this end, in this paper, we propose an attentional network named LSVP for POI recommendation, which adaptively considers the joint effects of users’ long-term, short-term and visual preferences. Specifically, we first extract visual preferences from photos, then extract long-term and short-term preferences from check-in sequences. At last, an adaptive attention mechanism is used to balance all the extracted users’ preferences. Experimental results on two real-world datasets collected show that LSPV provides significantly superior performances compared to other state-of-the-art POI recommendation models in terms of accuracy.
Chen Shi, , Miaoxin Hu,
Published: 25 July 2021
Neurocomputing, Volume 446, pp 192-203; doi:10.1016/j.neucom.2021.01.105

Abstract:
It is a time-consuming and laborious task to conduct accurate geological interpretation based on large-scale logging data. A subset of drilling wells are always selected undergoing detailed stratigraphic correlation, aiming to enhance the efficiency of geological interpretation and retain the matching accuracy of stratigraphic structures. However, standard wells are selected by hand in the course of traditional standard well selection, which will easily bring many uncertainties for subsequent interpretation of geological structures. In this paper, we propose a visual analytics system to support supervised standard well selection via a discrete choice model. Firstly, an adaptive blue noise sampling model is applied to determine spatial distribution of standard wells, and a stratigraphic correlation model is designed to measure the similarity between drilling wells from different attribute perspectives. Then, we utilize a discrete choice model to select standard wells with the spatial distribution and multiple attributes taken into consideration. Furthermore, several meaningful visualizations are designed allowing users to get deeper insights into the selection of standard wells, and a rich set of interactions are also provided enabling users to further optimize the discrete choice model. At last, a visualization framework is implemented to integrate the models and visual designs, by means of which the geological interpreters are able to visually select, evaluate and optimize the standard wells. The effectiveness of our work and its application values for geological interpretation are further demonstrated through case studies based on real-world datasets and interviews with domain experts.
Jiayi He, Xuefeng Liao, Xuexia Lan, Wanqi Qiu, Hongya Yu, Jiasheng Zhang, Wenbing Fan, Xichun Zhong,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159229

Abstract:
A novel method is proposed for Nd-Fe-B magnets to achieve both surface protection and grain boundary modification by using annealed Al-Cr coating. In detail, Cr was introduced into Al coating of Nd-Fe-B magnets by sputtering deposition using Al-Cr targets. A follow-up annealing at 550 °C was carried out to diffuse Al atoms into the grain boundaries of the magnets. It was found that Cr addition can significantly improve the hardness of Al coating and modify the diffusion process of Al. The annealed Al50Cr50 coating exhibited a hardness of 1011 ± 1 HV, ~5 times as high as the Al coating. The great adhesion was also obtained between the Al-Cr coating and Nd-Fe-B substrate. Most importantly, the introduction of Cr can effectively enhance corrosion resistance of the annealed coating due to its densification effect on the coating by modifying Al diffusion process. The coercivity of the magnet increased 95 kA/m and 89 kA/m by diffusing the Al80Cr20 and Al70Cr30 coatings, respectively, due to the Al diffusion caused microstructure modification. The present work demonstrated that the surface treatment and grain boundary diffusion can be combined into one process by Al-Cr coatings for high-performance Nd-Fe-B magnets with high hardness, strong adhesion, sufficient corrosion resistance, good anti-oxidation and improved coercivity.
Hans Orthner, Hartmut Wiggers, Moritz Loewenich, Stefan Kilian, Stefan Bade,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159315

Abstract:
High specific capacity of silicon is very attractive for its application as anode material in lithium ion batteries. However, the implementation of silicon is challenging due to its large volume expansion on lithiation leading to pulverization and buildup of a solid-electrolyte interphase. Nanostructuring and design of silicon alloys are a promising strategy to circumvent these challenges. Here we demonstrate an industrially scalable gas phase synthesis method using thermal decomposition of silane and ethylene to produce novel amorphous silicon/carbon-based particles with enhanced electrochemical performance. Fundamental principles and kinetics considerations for the design of high-performance silicon/carbon-based materials are discussed.
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159329

Abstract:
Laser Powder Bed Fusion (LPBF) is an additive manufacturing technology which has been the subject of thorough research and successfully adopted in several industrial sectors. Among all the processable classes of materials, titanium alloys are especially interesting due to their favourable combination of mechanical properties and corrosion resistance. Most of the literature focuses on Ti-6Al-4V, although there are other alloys which are widely applied in fields that can benefit from the advantages of LPBF techniques, such as Ti-6Al-2Sn-4Zr-6Mo, thus far not investigated for this technology. This alloy is generally preferred to Ti-6Al-4V for the production of some components in the aerospace industry, mostly due to its superior strength. In this work, the most suitable process window for this alloy was investigated. Samples produced with two different combinations of process parameters, located in the selected process window, were then thoroughly studied in order to assess the effect of building conditions on the microstructure, phases and mechanical properties of the as-built and heat-treated material. To do so, an X-ray diffraction analysis was conducted with the aim of determining the phase composition and lattice parameters. Moreover, microstructural features, such as α” needles and α lath widths, were analysed in order to correlate the thermal history of the process to the final microstructure of the specimens. Furthermore, the hardness and the tensile properties of the alloy processed by LPBF were quantified and compared with the data available in the literature relative to conventional manufacturing technologies.
Haochen Lu, Qiubo Guo, Qi Fan, Liang Xue, Xingyu Lu, ,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159341

Abstract:
Lithium-sulfur (Li-S) batteries are considered to be one of the most promising next-generation energy storage systems, due to their low cost and high theoretical energy density (2600 W h kg −1). However, the shuttle effect seriously limits the practical use of Li-S batteries. In this work, we demonstrate cobalt sulfide quantum dot embedded nitrogen/sulfur-doped carbon nanosheets composite material (CoSx QD-NSC) as coating material for commercial polypropylene (PP) separator (celgard 2400) in Li-S batteries. It is able to act as an efficient barrier for the blocking of polysulfides in Li-S batteries. The cell with modified separator, at the sulfur loading of 1.6 mg cm−2, can exhibit a high initial specific capacity of 1250 mAh g −1 at 500 mA g−1, with a capacity retention of 73.6% after 100 cycles. When cycled at 1 C (1675 mA g−1), the cell can deliver a high initial specific capacity of 874 mAh g−1 and a reversible specific capacity of nearly 500 mAh g −1 after 1000 cycles, exhibiting an average capacity fading of only 0.05% per cycle. The excellent performance is ascribed to the efficient adsorption of the CoSx QD-NSC to polysulfides, which inhibits the shuttle effect in Li-S batteries. The CoSx QD-NSC modified separator in this work provides new insights and opportunities for the development of advanced Li-S batteries.
Lin Yue, Yunmeng Cao, Yonghui Han, , Xiao Luo, Yanfang Liu
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159339

Abstract:
The magnetic metal-organic framework composite [email protected] with core-shell structure was successfully prepared by hydrothermal synthesis. It was characterized by XRD, TEM, BET, DRS, FT-IR, XPS and VSM. The photocatalytic performance of the composite was evaluated by degradation of Acid Red 3R (AR3R) dye under simulated light source. Under the conditions that the additive amount of the catalyst was 6.7 g/L, the initial concentration of AR3R was 50 mg/L and the initial pH of AR3R was 3.0, [email protected] revealed the optimized photocatalytic activity with 100% degradation efficiency of AR3R at 30 min. The excellent photocatalytic ability was mainly ascribed to the effective charge separation, strong photo-response and rich active sites. Besides, using Fe3O4 as the magnetic nucleus was conducive to improve the recovery rate of the catalyst. The EPR and free radical analysis indicate that •O2− and •OH played important roles in the photocatalytic reaction. Meanwhile, a possible degradation process and mechanism were proposed by the full band scanning of AR3R, 3D-EEM fluorescence analysis and electrochemical measurement.
Yiru Li, Wen Zheng, Aibo Zhang, Zhiyuan Xie, Moxi Liu
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159368

Abstract:
The silver microspheres with controllable morphology and structure were prepared by electroless plating with activated PS microspheres as template, which were used to construct a 3D absorbing hybrids of [email protected] The SEM and EDS results illustrated that a uniform silver shell was coated on the surface of PS microsphere because of the activation, which was conductive to construct an excellent conductive network to attenuate electromagnetic wave. Meanwhile, the plating solution concentration had an important effect on the morphology of Ag microsphere and microwave absorption performances of the absorbing hybrids. When the concentration was 12 g/L, the silver shell of B-2 microsphere was uniform and dense. However, lower or higher concentration were unfavorable to the integrity of Ag shell of B-1 and B-3 microsphere. For the [email protected] absorbent hybrids, the reflection loss value was −37.00 dB at 9.9 GHz, while that of [email protected] and [email protected] hybrids were −27.35 dB at 8.5 GHz and −24.07 dB at 11.3 GHz, respectively. All the results indicated that the controlling measures of activation for PS microspheres and proper plating solution concentration are crucial to enhance the microwave absorbing performances of absorbing hybrids.
, Francis Chi-Chung Ling, Shuang-Peng Wang, Ke Xiao, Xiaodong Cui, Qing Rao,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159344

Abstract:
Indium selenide (In2Se3) has got much recent attraction in a variety of research areas mainly due to its multiphase structure. Many existing studies, however, have focused on growth of α and β phase, while chemical vapor deposition (CVD) growth of the γ-phase has only been achieved for micon-thick flakes with the assistance of iodine trichloride (ICl3) catalysts. Here, we present the “catalyst-free” CVD growth of β and γ phase In2Se3 flakes with thicknesses down to only a few nanometers. The structural, optical and ferroelectric properties of the grown samples were investigated carefully by using various techniques. Optical microscope and Raman spectroscopy studies revealed that triangular and hexagonal shaped β and γ phases were grown at different substrate temperatures, respectively. The second-harmonic generation (SHG) measurement confirmed that β has centrosymmetric structure and γ phase has non-centrosymmetric structure. The ferroelectric properties of the γ-In2Se3 were measured along in-plane (IP) and out-of-plane (OOP) directions, for the first time, by employing piezo-force microscope (PFM). The non-monotonic thickness dependence of the ferroelectricity was found and explained with the combination of Raman and SHG measurements. The catalyst-free growth of γ-In2Se3 and the observation of ferroelectricity in it would be a valuable addition in the field of ferroelectric and piezoelectric switching devices.
Junfeng Zou, Qi Zhu, Xiaodong Li, Xudong Sun,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159380

Abstract:
With maleic acid (MA) as an original and efficient structure/morphology modifier, tetragonal (t-) and hexagonal (h-) structured (Y0.95Eu0.05)PO4 nano/microcrystals with the diverse morphologies of nanoparticles, nanospindles, nanosquares, nanodisks and microprisms have been successfully synthesized via hydrothermal reaction at 180 °C for 24 h. The systematic study demonstrated that solution pH, MA/(Y0.95Eu0.05)3+ molar ratio and PO43-/(Y0.95Eu0.05)3+ molar ratio are three crucial factors that synergistically determine phase structure and crystal shape/size of the product, and the underlying mechanisms were proposed. Photoluminescence of the (Y0.95Eu0.05)PO4 crystals was revealed to be strongly morphology/structure dependent, which was discussed in detail in terms of excitation, emission, asymmetry factor of luminescence, quantum yield, fluorescence decay, emission color and thermal stability.
Ruoxu Wang, , Ming Duan, Jing Xu, Mei Liu, Dan Luo
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159385

Abstract:
A novel CdS/Bi2MoO6/BiOBr successive Z-scheme photocatalyst has been synthesized by a solvothermal-precipitation method. The structure, composition, morphology and optical property of the ternary composite were investigated. The maximum degradation rate of CdS/Bi2MoO6/BiOBr for tetracycline hydrochloride (TC) can reach 94.41% under visible light, while its degradation rate was 10.43, 2.89, and 2.43 times higher than that of pure Bi2MoO6, BiOBr and Bi2MoO6/BiOBr, respectively. Besides, the CdS/Bi2MoO6/BiOBr composite showed stable catalytic performance after three successive reuses. The improved photocatalytic and stability could be ascribed to the extended visible-light absorption capability, effective separation of electron-hole pairs and layered stable structure. Photoluminescence spectroscopy and electrochemical impedance spectroscopy proved that the composite had more efficient charge separation efficiency. The energy band structure and free radical capturing experiments proved that the redox reaction mainly occurred in the conduction band of CdS and the valence band of BiOBr in this composite, so a possible successive Z-scheme heterojunction mechanism is proposed. This work also provides a feasible idea for the treatment of TC in wastewater.
Fen Qiao, Wenjie Liu, Shenzhi Wang, Fengjian Lin, Yuan Chen, Ming Yuan, Zhankun Weng, Sichao Wang, Jihua Zheng,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159393

Abstract:
Two-dimensional (2D) molybdenum sulfide has been considered a promising electrode material for high-performance supercapacitor owing to its superior electrochemical properties. However, molybdenum sulfide suffers from severe layers stacking and agglomeration, which lower the number of electrochemically active sites along the basal plane and result in dramatic and fast fading of capacity upon cycling and low Coulombic efficiencies. Herein, we fabricated the hierarchical Co3S4/CoS/MoS2 nanoflakes array grow on carbon cloth via a new scalable technique using the leaf-like Co-ZIF-L as a precursor. An optimal structure and electrochemical performance of the hierarchical nanomaterial are achieved after tune the stoichiometric ratio of the reactors. Due to the unique morphology, plenty of macropores, and vast of active sites, the hierarchical bimetallic sulfides nanoflakes array as an electrode not only present high specific capacitances (805.7 F g−1 at 1 A g−1) but also long cycle lifespan (91.2% of the initial value after 6000 cycles) and 100% of Coulombic efficiency. The strategy developed here can be further extended to design and construct other advanced heterostructure metal sulfides electrode materials for highly efficient energy storage and conversion applications, such as electrocatalysts, metal-ions batteries, and fuel cells.
, S.A. Ivkov, A.V. Sitnikov, O.V. Stogney, A.T. Kozakov, A.V. Nikolsky, K.A. Barkov, N.S. Builov
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159398

Abstract:
The influence of relative content of the metal component on the phase composition and substructure of (CoFeZr)x(MgF2)100−x film nanocomposites between x = 7÷51 (at%) has been established by X-ray diffraction (XRD), X-ray electron spectroscopy (XPS) and infrared spectroscopy (IR). Ion-beam sputtering of a composite target from Co45Fe45Zr10 amorphous alloy plate with MgF2 dielectric inserts allow prepared micron-thick nanocomposite layers in the argon atmosphere. The results show that at a relatively low content х25, the MgF2 matrix becomes X-ray amorphous, and CoFeZr alloy nanocrystals of the hexagonal syngony based on the α-Co structure with dimensions of about 10 nm are first formed; they are predominantly oriented in the plane of the hexagonal lattice (001). With a further increase of the metal alloy content up to х~40 in the region nearer to the percolation threshold, the crystal structure of nanocrystals of the CoFeZr alloy becomes a cubic phase based on α-Fe with a preferred orientation of (110). XPS studies confirm the presence of a predominant type of metal bonds in clusters and nanocrystals of CoFeZr, despite the oxidation of the thinnest surface layers, as well as ionic bonds in the MgF2 dielectric matrix, preserved because of self-organization even in non-equilibrium conditions of ion-plasma sputtering. Two features on the curve of the dependence of the resistivity of nanocomposites on the alloy concentration are due to: the first one (x~25) - the formation of nanocrystals of hexagonal symmetry from clusters of the amorphous CoFeZr alloy, and the second one (x~40) nearer the percolation threshold - coincides with the phase transition of nanocrystals from hexagonal to cubic structure.
, Kiyohide Wada, , Reza Katal, Sajjad Rimaz
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159399

Abstract:
Dependence of transformation temperatures of TiAu- and TiIr-based Intermetallics on Valence Electron Ratio (VER), number of valence electrons (ev) and average atomic number of the alloys (Z) were investigated. The alloys mostly have medium numbers of valence electrons (6.5 ≤ ev ≤ 7.3) near 7 with a limited number of TiAu-based alloys belonging to high valence electron group with ev more than 7.50 and relatively narrow range of average atomic numbers (Z = 41–53). The forward and reverse phase transformation temperatures, Ms and As of AuTi-based alloys sharply increase with the average atomic number of the alloys. The investigated TiIr alloy compositions have almost similar average atomic numbers (49.5–50.2). Clear correlations between transformation temperatures and VER were found. Ms and As both decrease from around 1550 °C to as low as 17 °C respectively, with increasing VER from 0.131 to 0. 174. The dependence of transformation temperatures on valence electron ratio is discussed based on the variations of elastic properties and atomic bonding due to composition change in these alloys.
Ki-Wook Sung, Dong-Yo Shin,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159404

Abstract:
Interface engineering of LiMn2O4 (LMO) is a promising strategy to enhance the lithium storage capability and cycling stability of cathode materials in Li-ion batteries (LIBs). This is because the strategy prevents structural degradation; however, Li storage kinetics remains unsatisfactory, resulting in poor ultrafast cycling performance. Therefore, we fabricated an Nb-doped TiO2 (NTO) functional layer as a conductive passivation layer on the LMO surface by horizontal ultrasonic spray pyrolysis deposition. The NTO functional layer suppressed the volume expansion of LMO and exhibited high electrical and ionic conductivity, which resulted in improved structural stability of LMO (related to cycling stability) and increased electron/ion transfer rate (related to ultrafast cycling performance). In the TiO2 structure, Ti4+ ions were replaced by Nb5+ ions, which possess high electrical conductivity and a wide c-axis as a Li-ion diffusion route. As a result, the NTO-coated LMO cathode material showed an outstanding specific capacity of 112.7 mAh/g with a remarkable capacity retention of 96.2% after 100 cycles at a current density of 1 C and excellent ultrafast cycling capacity and stability of 70.0 mAh/g after 500 cycles at a current density of 10 C.
S.S. Dash, , X.Q. Zeng,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159413

Abstract:
Aluminum alloy is today considered as a prime selection for manufacturing lightweight structural components in the automotive industry to increase fuel efficiency and reduce harmful emissions. The aim of this study was to identify the effect of microstructure and strain rate on the tensile deformation behavior of a high-pressure die-cast Silafont®-36 alloy, with special attention to strain hardening behavior and deformation mechanisms. The alloy consisted of randomly oriented primary α-Al phase and Al–Si eutectic structure in a form of heterogeneous microstructures, with Sr-modified Si particles exhibiting a coral-like fibrous network. The local misorientations in most primary α-Al grains was below 1°, suggesting strain-free grains along with some extent of near-boundary residual strains due to the thermal mismatch between aluminum and silicon. A superior strength-ductility combination was achieved, along with enhanced Young’s modulus and quality index owing to the unique heterogeneous microstructures. The cast alloy exhibited a smooth deformation characteristic with good coordination deformation and strong strain hardening capacity. Strain hardening exponents evaluated via the equations proposed by Ludwik, Hollomon, Swift, and Afrin et al., respectively, showed basically the absence of strain-rate effect from 1 × 10−5 to 1 × 10−2 s−1. During the tensile deformation, crack initiated from the sample surface and propagated through the alternate microconstituents of softer primary α-Al phase and harder eutectic structure.
Shuyun Wan, Xi Liu, LiKang Fu, Chengbao Zhou, Hongyi Chen, Guanghui Li, Shiyue Cao, Qiming Liu
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159407

Abstract:
Stannous sulfide (SnS) with low-cost and high theoretical specific capacity possesses enormous potential in the application of lithium-ion batteries (LIBs). However, the sluggish Li ion diffusion kinetics and severe volume variation of SnS, result in inferior rate capability and poor cycling stability. Hollow SnS microflower spheres coated with N, S dual-doped carbon ([email protected]) are constructed through a facile hydrothermal reaction, polydopamine encapsulation and subsequent carbonization process. Such rational hollow structure is conducive to enhance the structural stability of the material. More importantly, N, S dual-doped carbon is synergistically coupled with SnS, which can greatly improve the electrons/ions kinetics and mitigate the volume expansion. As consequence, the [email protected] composite electrode exhibits an admirable specific capacity of 778.5 mAh g−1 at 0.5 A g−1 after 400 cycles. It still remains a specific capacity of 633.8 mAh g−1 after 800 cycles even at 1.0 A g−1, corresponding to 81.7% of initial capacity. After being assembled into a full cell, the device delivers a stable capacity of 317 mAh g−1 at 0.1 A g−1. This work manifests that morphology and structure engineering have bright prospects in promoting the practical applications for metal sulfides.
Jingxia Gao, Luyuan Wang, Ping Zhu, , Guoxiang Wang,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159417

Abstract:
Exploiting highly active non-noble metal catalyst with designed nanoarchitecture is essential and formidable for the rechargeable Zn-air batteries (ZABs). To this end, hierarchically porous N-doped carbon hybrids with encapsulated FeCo alloy ([email protected]) is designed by template-assisted method. The optimized sample pyrolyzed at 800 °C ([email protected]) possesses a large specific surface area of 1195 m2 g−1, plentiful micro-/meso-/macro-pores and is rich in defects and graphitic N-doped carbon atoms. These preeminent characteristics endow the catalyst with superior bifunctional oxygen electrocatalytic activities (ΔE = E10-E1/2 =852 mV) in alkaline electrolyte, as well as outstanding stability. As air-electrode catalyst in ZAB, [email protected] reveals high power density of 169 mW cm−2, excellent rechargeable property and cycling stability. Moreover, the as-obtained catalyst displays promising application potentiality in solid-state ZAB.
A.G. Abd-Elrahim,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159430

Abstract:
ZnO-graphene nanosheets photoanodes were deposited at room temperature by a one-step kinetic spray process on a titanium sheet from micro-sized ZnO and graphite powders. ZnO-graphene nanosheet hybrid photoanodes with varying graphite contents were utilized for studying photoelectrochemical (PEC) water splitting. The Raman spectra revealed the direct transformation of micro-sized graphite powder to graphene nanosheets in all hybrid photoanodes after the deposition process, without any post-treatment. Surface morphology analysis revealed the fragmentation of the micro-sized flake morphology to morphology composed of mixed nanorods and nanosheets. The optical properties of the ZnO-graphene nanocomposites were investigated by the diffuse reflectance and photoluminescence (PL) emission spectroscopy, which revealed the decrease of the optical band gap and quenching of PL intensity. The hybrid photoanode with 50 wt% graphite content revealed the smallest bandgap of 2.6 eV and the lowest emission intensity compared with other hybrid photoanodes, which demonstrated the inhibition of photogenerated charge carrier recombination rate as well as an improvement in the visible-light-harvesting. The PEC results exhibited an improvement of the photocurrent with the incorporation of graphene nanosheets due to the improved photogenerated charge transfer kinetics and separation. The hybrid photoanode with 50 wt% graphite content revealed the highest photo-response current of 4.82 mAˑcm−2 corresponds to photoconversion efficiency of 3.25% @1.23 V vs. RHE.
Jian Zhang, DaQian Bian, Gang Shao, Hailong Wang, Changan Wang
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159415

Abstract:
Supported noble metal catalysts have a wide range of applications in heterogeneous catalysis, but poor thermodynamic stability greatly hindering their practical applications. In this article, we have prepared sandwich-like [email protected][email protected]2 hollow spheres by template method, in which Pd nanoparticles were embedded in the porous MnO2 shell. Compared with the conventional supported catalysts, the sandwich structure design can significantly improve the thermal stability of the catalyst without considerably sacrificing its catalytic activity. It is believed that this method provides a new way to prepare a catalyst with high activity and excellent thermal stability.
Dawei Wei, Xiaofeng Bai, , ,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159406

Abstract:
The isothermal sections at 1373 and 1473 K in the Co–Nb–Ti system were constructed using annealed diffusion couples and equilibrated alloys by using scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), electron probe microanalysis (EPMA), and X-ray diffraction (XRD) techniques. Three three-phase regions, Co2(Nb,Ti) + Co7Nb6 + CoTi, Co7Nb6 + CoTi + bcc(Nb,Ti), and CoTi + liquid + bcc(Nb,Ti) were determined. Co3Nb and α-Co2Ti with a C36 crystal structure, and Co2Nb and β-Co2Ti with a C15 crystal structure at 1373 and 1473 K formed continuous solid solutions Co3(Nb,Ti) and Co2(Nb,Ti), respectively. The solubilities of Ti in Co7Nb6 and Nb in CoTi are determined to be ~11.4 at% and ~22.3 at% at 1373 K, and ~12.5 at% and ~24.8 at% at 1473 K, respectively. No ternary compounds were observed.
Bao-Guang Zhang, , Zhen Tian,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159425

Abstract:
Ag2Te is a potential thermoelectric material that has potential applications in the field of waste heat generation, with both “phonon-liquid electron-crystal” and superionic conductivity characteristics. However, the n-p-type conversion caused by phase transformation, as well as the bipolar effect resulting from a narrow energy gap, hinder the optimization of the dimensionless thermoelectric figure of merit (ZT). In this study, an Ag2Te-Cu2Te composite material was prepared by a solid-state method. The bipolar effect and n-p-type conversion of Ag2Te were inhibited by combining it with Cu2Te. High power factor was maintained, and the thermal conductivity was effectively reduced through Ni doping. Therefore, the ZT value increased, and reached 0.93 at 573 K, an increase of 41%, compared to the Ag2Te-Cu2Te without Ni doping.
Yuanyuan Cui, Kebing Yang, Lanli Chen, Bin Liu, Guang Yang,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159428

Abstract:
The interface between band insulator TiO2 and correlated insulator VO2 is a fertile ground for new behaviors. In the present paper, we conducted the first-principles calculations to study the interfaces of VO2(m)/TiO2(n) superlattices (referred as m/n for simplicity, where m and n denote the number of rutile VO2 and TiO2 layers, respectively). Interestingly, the VO2/TiO2 superlattices show insulating states in the 2/6, 4/6 and 6/6 systems with the oscillation of V-V distances, while the superlattices present metallic states in the 1/6, 3/6 and 5/6 systems as the oscillation of V-V distances is broken. Accordingly, we reported an alternating metal-insulator behavior in VO2/TiO2 superlattices with the increasing number of VO2 layers. These findings may help to better understand the Peierls structural transition in correlated insulator, and may bring a light to the Schottky barrier homojunction composed of different VO2(m)/TiO2(n) superlattices.
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159410

Abstract:
In the present study, the FexCoCrNi (x = 1, 1.3, 1.6) high entropy alloy (HEA) system was prepared by mechanical alloying (MA) and spark plasma sintering (SPS). The effect of iron content on the microstructure, mechanical properties, thermal behavior, and wear resistance of the FexCoCrNi (x = 1, 1.3, 1.6) HEA system was separately studied. It was found that all 3 alloys showed body-centered cubic (BCC) and face-centered cubic (FCC) solid solutions after 50 h of milling and an increase in the iron content was accompanied by an increase in the fraction of the BCC solid solution. Thermal stability of the FexCoCrNi (x = 1, 1.3, 1.6) HEA system was evaluated in the temperature range of 973–1273 K. The FCC structure was retained even after thermal exposure at 973, 1123, and 1273 K for all 3 alloys. The increase in Fe content led to a decrease in the sigma phase (FeCr or CoCr) formation temperature. The results of mechanical tests indicated that increasing Fe (1–1.6 mol) resulted in enhancement of ultimate tensile strength and hardness from 480 to 560 MPa and 320–400 Vickers, respectively. Wear resistance results demonstrated that the coefficient of friction (COF) and weight loss of this system decreases with increased Fe content. Moreover, the dominant wear mechanism changed from abrasive wear to adhesive wear.
Swayam Kesari, Alka B. Garg, Oliver Clemens,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159418

Abstract:
Tetragonal Mn3(VO4)2 is a metastable high temperature phase of Mn3(VO4)2 showing unusual coordination of Mn atoms. A nominal Li-substitution helps to stabilize the tetragonal modification. We report room temperature compression of Li-stabilized high-temperature tetragonal phase of Mn3(VO4)2 with composition Li0.2Mn2.9(VO4)2 studied by in-situ Raman spectroscopy and synchrotron X-ray diffraction up to pressures of 20 and 26.5 GPa respectively. Raman spectroscopy suggests onset of a structural phase transition at around 10 GPa which completes above 13 GPa. X-ray diffraction also suggested a first order structural transition above 10 GPa, with a coexistence range of two phases up to 13 GPa. High pressure phase is found to be different from the known thermodynamically stable orthorhombic structure of Mn3(VO4)2. The equation of state data of the ambient tetragonal phase has been obtained. Anisotropic compression is observed with the c-axis being more compressible than a-axis. Using experimental bulk modulus, the mode Grüneisen parameters for the observed Raman frequencies for the ambient phase have been obtained. On pressure release, the high pressure phase could be retrieved.
Lixia Xi, Kai Ding, , Shuang Guo, Mengzhen Cao, Jie Zhuang, Kaijie Lin, Ilya Okulov, , Jürgen Eckert, et al.
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159436

Abstract:
High-fraction ceramic particulate-reinforced titanium matrix composites were manufactured by selective laser melting (SLM) from starting powders containing Ti-TiC, Ti-TiN, Ti-TiC-TiN and Ti-TiN-graphene. The microstructures of the composites were characterized to reveal the constitution of the reinforcements, the matrix as well as the formation of interfacial structure via ex-situ and in-situ synthesis routes. The microhardness of the SLM-fabricated composites is at least three times higher than that of unreinforced Ti due to high density of hard ceramic reinforcements. A coefficient of friction (COF) value of 0.792 and a wear rate of 1.0 × 10−4 mm3/N−1m−1 were obtained for the SLM-processed Ti/(TiC+TiN) composites by ex-situ addition of TiC and TiN ceramic particles due to the favorable interfacial structure formed between these hybrid reinforcements and good manufacturing quality. This study proposes a unique interfacial structure by combination of hybrid reinforcements that allows to improve the manufacturing quality and wear properties of SLM-fabricated titanium matrix composites.
Yan Zhang, Jin Yu, Jiayu Lu, Chenjie Zhu,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159442

Abstract:
Rapid growing of electronics has not only caused severe electromagnetic wave pollution, but also created a risk of fire and explosion. Therefore, developing ultralight, fire-resistant, high-performance electromagnetic interference (EMI) shielding materials are imperative but also challenging. Considering the outstanding metallic conductivity and high aspect ratio, 2D Ti3C2Tx has been reported to be one of the most promising candidates for exhibiting excellent EMI shielding performance. Herein, we demonstrate a facile method to fabricate cellulose nanofiber (CNF)/ammonium polyphosphate (APP)/Ti3C2Tx composite aerogels via a simple freeze-drying method. The resultant CNF/APP/Ti3C2Tx composite aerogels exhibited excellent fire-resistance without obvious shrinkage when placed over the flame of an alcohol burner. Besides, the 8-mm-thick composite aerogel with 60% of Ti3C2Tx showed an average EMI shielding effectiveness of 55 dB (specific EMI shielding effectiveness/thickness could be ~5729 dB cm2 g−1) with an absorption-dominant mechanism. This performance is owing to the relative high electrical conductivity (12 S/m) and multiple reflections from the porous structure. These characteristics make the composite aerogel a much more competitive product for a high-performance EMI shielding material.
Shuncun Luo, Yue Su,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159443

Abstract:
This article discusses the influence of the Ni content on the microstructures of AlCrCuFeNix complex concentrated alloys prepared by selective laser melting. The microstructural evolution mechanisms were also uncovered. It is found that the as-built Ni1.0 alloy possesses equiaxed-columnar bimodal grain structures and basket-weave microstructure consisting of striped body-centered cubic (bcc) nano-precipitates and ordered bcc (B2) phase. Adding Ni triggers the lattice transition from B2 to face-centered cubic (fcc), leading to the change of the primary solidification phase from B2 to fcc beyond the critical content of Ni. Meanwhile, the striped bcc nano-precipitates inside the B2 lamellae gradually transform into spherical morphologies due to the consumption of Fe and Cr solutes in eutectic reaction. Furthermore, the microstructures change from hypo-eutectic (Ni2.0, Ni2.5) to near-eutectic (Ni3.0) to hyper-eutectic (Ni3.5), accompanied by a columnar-to-equiaxed transformation due to the large constitutional supercooling induced by the eutectic reaction.
Jun Chen, , Huazhi Gu, Ao Huang, Hongwei Ni
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159463

Abstract:
SiC is extensively used in high-temperature industrial furnaces because of its excellent slag resistance. However, it suffers from poor sinterability due to strong covalent bond and low self-diffusion coefficient, which does harm to mechanical properties of SiC based materials. In this work, induction heating and addition of Al-Si alloy were used to improve the mechanical performance of phenolic resin bonded SiC bricks. The results showed that the addition of the Al-Si alloy to the phenolic resin bonded SiC bricks resulted in the formation of an in situ Al4SiC4 binder phase after heat treatment at 1700 °C for 2 h, which significantly improved the mechanical properties of the bricks. Furthermore, compared with ordinary heating, SiC bricks had more excellent properties after induction heating. Because the induced electric field can promote the wetting of the SiC aggregates by the Al-Si-C drops during induction heating, which caused the in situ Al4SiC4 binder phase besieged the SiC aggregates. Good mechanical properties were obtained owing to the generation of the new binder phase.
Jiaheng Wang, Jiaxu Gong, Huan Zhang, Linlin Lv, Yuxing Liu, Yatang Dai
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159466

Abstract:
Designing and adjusting materials with reasonable microscopic morphology is the key to improving electrochemical performance and assembling hybrid supercapacitors with excellent performance. In this work, firstly, a hydrothermal method is used to grow the NiCo-MOF (NCM) on nickel foam, then NCM is used as the precursor, and the solution containing MXene and Ni2+ and Co2+ are used as the electrolyte to prepare the [email protected]/NF ([email protected]/NF) nanosheets through electrodeposition. Since the metal cations will be redistributed between the MXene layers, the nanosheets obtained by electrodeposition in the electrolyte added with MXene exhibit a unique hexagonal nanosheet morphology. This unique form can enhance the electrochemical performance, the capacity retention rate can be maintained at 75.3% after 5000 cycles, and the specific capacity can reach 855.0 C g−1 (2137.5 F g−1) at 1 A g−1.
Published: 25 July 2021
Neurocomputing, Volume 446, pp 145-155; doi:10.1016/j.neucom.2021.03.004

Abstract:
Medical diagnosis supported by computer-assisted technologies is getting more popularity and acceptance among medical society. In this paper, we propose a non-intrusive vision-assisted method based on human action recognition to facilitate the diagnosis of Autism Spectrum Disorder (ASD). We collected a novel and comprehensive video dataset f the most distinctive Stereotype actions of this disorder with the assistance of professional clinicians. Several frameworks as a function of different input modalities were developed and used to produce extensive baseline results. Various local descriptors, which are commonly used within the Bag-of-Visual-Words approach, were tested with Multi-layer Perceptron (MLP), Gaussian Naive Bayes (GNB), and Support Vector Machines (SVM) classifiers for recognizing ASD associated behaviors. Additionally, we developed a framework that first receives articulated pose-based skeleton sequences as input and follows an LSTM network to learn the temporal evolution of the poses. Finally, obtained results were compared with two fine-tuned deep neural networks: ConvLSTM and 3DCNN. The results revealed that the Histogram of Optical Flow (HOF) descriptor achieves the best results when used with MLP classifier. The promising baseline results also confirmed that an action-recognition-based system can be potentially used to assist clinicians to provide a reliable, accurate, and timely diagnosis of ASD disorder.
De Wang, , Xiaoling Guo, Zhenyu Fu, Zhenglong Yang, Wenjuan Sun
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159472

Abstract:
Cheap and excellent conductive substrates with large and manipulated geometric area have become an indispensable research object for non-self-supporting OER electrode materials to achieve the practical application. In this study, low-crystallinity 2D morphology iron hydrogen phosphate material (FPO3) with thickness of 12–16 nm is obtained by an easy polyol refluxing method. Its overpotential drop-casted on nickel foam (FPO3/NF) for OER is just 309 mV at the current density of 10 mA cm−2. Through the detailed comparative analysis, its number and the intrinsic activity of active sites for OER effectively enhanced because of the two-dimensional morphology, the low crystallinity, the excellent redox activity of iron, and the more beneficial synergy between NF and FPO3. Those results also indicate that using NF as the substrate is a high-efficiency method to realize the practical application of non-self-supporting electromaterials by a simple drop-casted treatment.
L. Chouhan, Shantanu Kumar Panda, S. Bhattacharjee, B. Das, A. Mondal, B.N. Parida, R. Brahma, Murli Kumar Manglam, M. Kar, G. Bouzerar, et al.
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159515

Abstract:
D0 Ferromagnetic oxide materials have emerged as a promising material for possible application in spintronics. The recent theoretical calculation has predicted d0 ferromagnetism in Ag-doped SnO2 compounds. In this work, we have undertaken an investigation into structural, micro-structural, optical, magnetic, and electrical properties of Ag doped SnO2 compounds. Crystal structure study by the XRD pattern analysis confirms polycrystalline rutile phase with tetragonal structure. The SEM micrographs reveal the formation of uniform spherical nanoparticle morphology. The optical property study by UV/VIS spectrophotometer indicates the band-gap narrowing. A p-type conductivity was observed by Hall effect measurement and the hole concentration was found to increase with the increase in Ag doping. Ferromagnetism with Curie temperature ranging from 304 to 359 K is observed in all Ag-doped compounds, along-with a coercivity value of 240–1310 Oe, whereas un-doped SnO2 exhibited diamagnetism. The magnitude of dielectric constant and ac conductivity was observed to enhance with an increase in Ag concentration, which implies that the charge carriers' hopping is responsible for this transport. The observed ferromagnetism can be ascribed to a p–d hybridization between O and Ag ions.
Yuhan Ma, Mingyu Li, Jingjing Jiang, Tianren Li, Xingyue Wang, Yueyu Song,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159524

Abstract:
In this work, a series of MIL-53(Fe)/BiOI composites were synthesized by a combined hydrothermal and facile co-precipitation method. The heterojunctions were further used as photocatalysts for tetracycline (TC) degradation in photo-Fenton system. The TC degradation rate constant for MIL-53(Fe)/BiOI (0.0906 min−1) was 2.1 and 2.3 times higher than that for MIL-53(Fe) (0.0432 min−1) and BiOI (0.0389 min−1), respectively. The photoelectrical characterization results suggested that the enhanced photocatalytic activity of the MIL-53(Fe)/BiOI composite was attributed to the high electron and holes separation efficiency. The scavenging experiment results and electron spin resonance analysis demonstrated that h+ and singlet oxygen were the main reactive species in the degradation process. The possible photo-Fenton degradation mechanism was further elucidated based on the band structures of MIL-53(Fe) and BiOI with the generation process of reactive species. This work provided a new idea to construct metal-organic-framework-based composite photocatalysts for photo-Fenton system, and it is also promising for the applications in environmental restoration and protection field.
Shasha Xiao, , Xian Zhang, Jun-Wei Zhu, Xin Yang
Published: 25 July 2021
Neurocomputing, Volume 446, pp 86-94; doi:10.1016/j.neucom.2021.03.022

Abstract:
We address the state estimation problem for a class of genetic regulatory networks (GRNs) with leakage and discrete heterogeneous delays in this paper. In order to simplify the complexity of designing the state estimator for nonlinear delayed model of GRNs, a state estimate algorithm based on a model transformation method is presented, which goal is to get the entire system state. First, in light of the Lagrange’s mean-value theorem, the nonlinear model transformation method is applied to describe the nonlinear error system as a linear time-varying model. Second, by constructing the Lyapunov–Krasovskii functional dependent on the composite function variables of state estimate errors, a new technique lemma is provided and applied to the stability analysis. Third, the sufficient condition of state estimator design is obtained in term linear matrix inequalities, under which, the certification of the uniform asymptotic stability for state estimate error system is derived. Finally, a simulation example illustrates the rationality and effectiveness of the proposed theoretical results.
Chang Zhou, ,
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159482

Abstract:
Electrically assisted creep age (ECA) forming of an Al-Cu-Li alloy, when applied electropulsing during the different stages, has been experimentally investigated under the applied stress of 160 MPa at 160 °C for 20 h. Creep strain of the sample assisted by electropulsing when introduced during the initial creep stage increased by ~27.2% comparing with that of conventional creep ageing test (CCA) at the end of 20 h. However, there is almost no effect on creep strain when applied electropulsing at the beginning of 4, 8 and 19 h. Tensile tests indicate that strength of the aged specimens assisted by electropulsing when applied during the different creep stages is almost the same, but a slight reduction in elongation for the ECA specimen when introduced electropulsing during the initial stage and an increase by ~27.4% in elongation of the ECA specimen when introduced electropulsing during the last stage, compared to that of the CCA specimen. The fractograph of aged samples assisted by electropulsing when applied during the various creep stages, was observed to an obvious difference. Transmission electron microscopy (TEM) observations show that applying electropulsing during the early creep stage can accelerate dislocation motion, which for the first time proven by the observed larger dislocation structure, and promote Li solutes diffusion to grain-boundary, which is responsible for an increased creep strain and a decreased elongation, respectively. And dissolution of the Cu-rich at grain-boundary and GPI zone/θ´ precipitates within the grain, induced by electropulsing when applied during the last creep stage, is considered as the cause of an increased elongation. Thus, applying electropulsing during both the initial and last creep age forming stages is a promising method to control the microstructure to attain a sound sheet metal forming/property synergy.
Yu-Qiang Jiang, , Guan-Qiang Wang, Guo-Dong Pang, Ming-Song Chen, Zhi-Chao Huang
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159534

Abstract:
The microstructure evolution of a Ti-55511 alloy deformed at high temperatures (from 1163 K to 1253 K) and wide strain rate range (from 10 s−1 to 0.001 s−1) is studied by isothermal compression tests. Based on the sensitivity of dislocation density to deformation conditions, a unified constitutive equation is established to describe the evolution of flow stress, grain size and dynamic recrystallization (DRX) fraction. The results show that the initial grain boundaries are serrated, and the sub-grains and DRX grains are formed with the further deformation. Furthermore, the discontinuous and geometric DRX mechanisms are dominant recrystallization mechanism. Increasing the deformation temperature can increase the DRX fraction and sub-grain size. However, the abnormal growth of β grains occurs at 1253 K. The DRX fraction decreases with the increased strain rate. Meanwhile, the chain-like small DRX grains and the flow localization occur at high strain rates. Also, the established constitutive model is verified by the experimental results, and the correlation coefficient is 0.9929, indicating the excellent prediction ability of the established constitutive model.
Changyu Dong, , Panfeng Yang, Xin Guo, Junqiang Ren, Hongtao Xue, Junchen Li, Fuling Tang, Hui Li, Yutian Ding, et al.
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159476

Abstract:
In this present contribution, molecular dynamics simulation was performed to investigate the tensile response and deformation mechanism under different influencing factors, such as Co content, crystallographic orientation, rate, temperature and void. It is concluded that the number of stair-rod dislocation is the maximum during the deformation process of single crystal nanopillars with the Co content of 10%. It is interesting that the aggregation formed by five stacking fault tetrahedron, whose edge is composed of stair-dislocation formed by the combination of the stacking fault and another incomplete dislocation, is present, responsible for the rise of stress in the plastic deformation curve (0.1 < ε < 0.13). When loading in the [111] direction, the dislocation density keeps a relatively high level compared to the other two directions. In addition, the prismatic dislocation loops are formed by the interaction, reaction and separation of Shockley, stair-rod dislocations by the intersection of the slip planes at an acute angle and Hirth dislocations at an obtuse angle at 50 K, having a fixed effect on the dislocation, which also leads to the increase of strength. The presence of the smaller void volume is conducive to the nucleation and expansion of dislocations, yet when the void volume is too large, the failure process is not dominated by dislocation but by stress concentration at the voids. The above results are beneficial to explore and design of this fascinating single crystal alloy in the fields involving aerospace and electronic power.
, , A.H.A. Rashid, N.A. Ali, N.A. Sazelee, S.N. Timmiati
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159469

Abstract:
A systematic investigation was performed on the 4MgH2 + LiAlH4 destabilized system with the inclusion of 5 wt% Al2TiO5 that was prepared by a ball milling process, and the hydrogen sorption performances were studied for the first time. A great advancement of the onset dehydrogenation temperature and de/rehydrogenation kinetics of 4MgH2 + LiAlH4 composite was achieved by doping Al2TiO5 to the composite. For the first and second desorption stages, the 4MgH2 + LiAlH4 + 5 wt% Al2TiO5 composite began to liberate hydrogen at 85 °C and 230 °C. In comparison, the undoped system commenced to liberate hydrogen at 120 °C and 270 °C, which were 35 °C and 10 °C lower, respectively when contrasted with the undoped composite. For the rehydrogenation kinetics, about 1.9 wt% hydrogen was absorbed within 5 min for the 5 wt% Al2TiO5-doped 4MgH2 + LiAlH4 system, whereas the neat sample only absorbed about 1.2 wt% hydrogen under similar conditions. As for the dehydrogenation kinetics, 4MgH2 + LiAlH4 + 5 wt% Al2TiO5 composite desorbed 1.7 wt% hydrogen within 10 min of desorption, while the 4MgH2 + LiAlH4 system released 0.8 wt% hydrogen in the same time frame. The apparent activation energy for the MgH2-relevant decomposition decreased from 121 kJ/mol (4MgH2 + LiAlH4 system) to 102 kJ/mol, after 5 wt% Al2TiO5 was introduced into the destabilized system. The decline in particle size also enhance the hydrogen storage behaviors. The synergistic effect of Al2TiO5 on the hydrogen storage behavior of 4MgH2 + LiAlH4 sample is attributed to the formation of new species of TiH2, AlTi2 and LiTi2O4 after ball milling and heating process, which acted as a real catalyser in the 4MgH2 + LiAlH4 + 5 wt% Al2TiO5 destabilized system.
Guoyu Sun, Ting Yang, Jingying Duan, Yang Zhang, Mingyue Wang, Rui Wang, Chengyang Wang
Published: 25 July 2021
Journal of Alloys and Compounds, Volume 870; doi:10.1016/j.jallcom.2021.159543

Abstract:
The shuttle effect of lithium-sulfur batteries leads to passivation of the lithium metal anode surface and loss of active sulfur, which seriously restricts its development. In order to eliminate the shuttle effect, a layer-by-layer N and P doped heterogeneous carbon materials ([email protected]@CNP) with gradient electric fields are rationally designed to limit the dissolution of polysulfide anions. Such heterogeneous structure is prepared by a simple MOF self-sacrificing template strategy via changing the types of organic ligands in the synthesis of multilayer MOF, thus realizing the gradient doping of N and P heteroatoms from the inner layer to the outer layer. DFT calculation proves that the doping of N and P heteroatoms can change the electronic structure of carbon materials and tune their electron cloud density. The hybrid atom gradient doping also induces the construction of gradient energy level. The gradient of electron cloud density increases to form an internal electric field, which restricts the diffusion of polysulfides to the anode and alleviates the loss of active sulfur caused by shuttle effect. At the same time, the doping of N and P heteroatoms enhances the conductivity of MOF derived carbon, promotes the charge transfer, and enhances the reaction kinetics. As a result, when the MOF derived carbon material ([email protected]@CNP) was used to modify the commercial PP separator, the lithium-sulfur battery shows excellent electrochemical properties with superior rate capability and robust cycling stability (737.2 mAh g−1 after 500 cycles at 1.0 C with a small capacity decay of 0.034% per cycle).
Anastasia Zerva, Athanasios Limnaios, Anastasia S. Kritikou, , Petros Taoukis,
Published: 25 July 2021
New Biotechnology, Volume 63, pp 45-53; doi:10.1016/j.nbt.2021.03.002

Abstract:
β-Galactosidases are key enzymes in the food industry. Apart from the hydrolysis of the saccharide bond of lactose, they also catalyze transgalactosylation reactions, producing galactooligosaccharides (GOS) with prebiotic activity. Here we report the heterologous production in Pichia pastoris of a novel β-galactosidase from the fungus Thermothielavioides terrestris. The enzyme (TtbGal1) was purified and characterized, showing optimal activity at 60 °C and pH 4. TtbGal1 is thermostable, retaining almost full activity for 24 h at 50 °C. It was applied to the production of GOS from defined lactose solutions and acid whey, a liquid waste from the Greek yoghurt industry, reaching yields of 19.4 % and 14.8 %, respectively. HILIC–ESI-QTOF-MS analysis revealed the production of GOS with up to 4 saccharide monomers. The results demonstrate efficient GOS production catalyzed by TtbGal1, valorizing acid whey, a waste with a heavy polluting load from the dairy industry.
Song-Lu Chen, Shu Tian, Jia-Wei Ma, Qi Liu, Chun Yang, Feng Chen,
Published: 25 July 2021
Neurocomputing, Volume 446, pp 1-10; doi:10.1016/j.neucom.2021.03.040

Abstract:
License plate detection is the first and essential step of the license plate recognition system and is still challenging in real applications, such as on-road scenarios. In particular, small-sized and multi-oriented license plates, mainly caused by the remote and mobile camera, are challenging to detect. We propose a novel and applicable method for degraded license plate detection via vehicle-plate relation mining in this work. The proposed method can detect the license plate in a coarse-to-fine scheme. First, we propose to estimate the plate by using the relationships between the vehicle and the license plate, which can significantly reduce the search area and precisely detect small-sized license plates. Second, we present to robustly detect the multi-oriented license plate by regressing the four corners of the license plate in the local region. The whole network is constructed in an end-to-end manner, and codes are available at https://github.com/chensonglu/LPD-end-to-end.
Published: 25 July 2021
Neurocomputing, Volume 446, pp 11-22; doi:10.1016/j.neucom.2021.03.048

Abstract:
Face super-resolution (SR) has become an indispensable function in security solutions such as video surveillance and identification system, but the distortion in facial components is a great challenge in it. Most state-of-the-art methods have utilized facial priors with deep neural networks. These methods require extra labels, longer training time, and larger computation memory. In this paper, we propose a novel Edge and Identity Preserving Network for Face SR Network, named as EIPNet, to minimize the distortion by utilizing a lightweight edge block and identity information. We present an edge block to extract perceptual edge information, and concatenate it to the original feature maps in multiple scales. This structure progressively provides edge information in reconstruction to aggregate local and global structural information. Moreover, we define an identity loss function to preserve identification of SR images. The identity loss function compares feature distributions between SR images and their ground truth to recover identities in SR images. In addition, we provide a luminance-chrominance error (LCE) to separately infer brightness and color information in SR images. The LCE method not only reduces the dependency of color information by dividing brightness and color components but also enables our network to reflect differences between SR images and their ground truth in two color spaces of RGB and YUV. The proposed method facilitates the proposed SR network to elaborately restore facial components and generate high quality 8× scaled SR images with a lightweight network structure. Furthermore, our network is able to reconstruct an 128×128 SR image with 215 fps on a GTX 1080Ti GPU. Extensive experiments demonstrate that our network qualitatively and quantitatively outperforms state-of-the-art methods on two challenging datasets: CelebA and VGGFace2.
Fei Yan, , Enze Zhang, Jian Guo, Qingwei Chen
Published: 25 July 2021
Neurocomputing, Volume 446, pp 130-144; doi:10.1016/j.neucom.2021.03.046

Abstract:
This paper presents a novel nonlinear adaptive sensor fusion method for integrated navigation systems with varying noise parameters. The innovation is utilizing deep neural networks to mine the noise-related patterns of specific sensors and combining it with conventional nonlinear filters. This hybrid approach improves the feasibility and robustness of adaptive filtering by achieving an effective estimation of the originally weakly observable noise parameters. The specific sensors are defined as α-type sensors whose errors are entirely generated by themselves. The mathematical model for analyzing α-type sensors output sequence and the deep neural network for mining the patterns of interest are established. All adaptive filtering systems using α-type sensors can benefit from this paper. Specifically, it is applied to inertial and satellite integrated navigation system. The numerical experiments indicate that the proposed filter achieves promising accuracy and robustness improvement as compared to conventional nonlinear filters. And the comparisons between different nonlinear approximation algorithms indicate that the first-order approximation is accurate enough for our application.
Hooman Mirzaee, Noelia L. Neira Peralta, Lilia C. Carvalhais, ,
Published: 25 July 2021
New Biotechnology, Volume 63, pp 54-61; doi:10.1016/j.nbt.2021.03.003

Abstract:
Bacteriocins are a diverse group of bacterial antimicrobial peptides (AMPs) that represent potential replacements for current antibiotics due to their novel modes of action. At present, production costs are a key constraint to the use of bacteriocins and other AMPs. Here, we report the production of bacteriocins in planta – a potentially scalable and cost-effective approach for AMP production. Nine bacteriocin genes with three different modes of action and minimal or no post-translational modifications were synthesized, cloned and used to transform Arabidopsis thaliana. To confirm bacteriocin functionality and the potential to use these plants as biofactories, Arabidopsis T3 crude leaf extracts were subjected to inhibition assays against the bacterial pathogens Clavibacter michiganensis subsp. michiganensis (Cmm) and Pseudomonas syringae pv. tomato DC3000 (Pst). Six and seven of nine extracts significantly inhibited Cmm and Pst, respectively. Three bacteriocin genes (plantaricin, enteriocin, and leucocin) were then selected for over-expression in tomato (Solanum lycopersicum). In vitro plant pathogen inhibition assays of T0, T1 and T2 transgenic tomato leaf extracts confirmed antimicrobial activity against both pathogens for all three generations of plants, indicating their potential use as stable biopesticide biofactories. Plantaricin and leucocin-expressing T2 tomato plants were resistant to Cmm, and leucocin-expressing T2 plants were resistant to Pst. This study highlights that plants can be used as biofactories for AMP production and that the expression of bacteriocins in planta may offer new opportunities for disease control in agriculture.
Published: 25 July 2021
New Biotechnology, Volume 63; doi:10.1016/s1871-6784(21)00054-6

Kyung Hoon Kim, Jong Hoon Cho, Jin Ung Hwang, Ji Sun Im,
Journal of Industrial and Engineering Chemistry, Volume 99, pp 48-54; doi:10.1016/j.jiec.2021.04.002

Abstract:
A solid electrolyte interphase (SEI) on an anode is a critical issue in lithium-ion batteries because it is related to cycling stability. In this study, we introduce a semi-ionic CF bond on the surface of graphite (SICF) via plasma fluorination to introduce a LiF-based SEI layer on the anode during the first cycle. In the charge-discharge profiles and cyclic voltammetry curves, a peak related to the LiF-based SEI formation was clearly observed for SICF. In particular, SICF had an excellent long-term cycling stability of 98.8% for 100 cycles (1.0 C-rate). From the anodes of the disassembled coin cells, it was found that semi-ionic CF bonds improved the formation of a stable LiF-based SEI layer and decreased the number of side reactions with HF, which was produced from PF5. Moreover, SICF exhibited a lower volume expansion compared to that of the pristine anode and the anode with covalent CF bonds. Therefore, introducing a semi-ionic CF bond via plasma fluorination is a key strategy for forming a LiF-based SEI layer on the graphite anode surface that enhances the cycling stability of lithium-ion batteries.
Edoardo Magnone, Hong Joo Lee, Min Kwang Kim,
Journal of Industrial and Engineering Chemistry, Volume 99, pp 74-80; doi:10.1016/j.jiec.2021.04.009

Abstract:
In this study, an experimental method for estimating the relative membrane mass transfer resistance (RmHFMC) by comparing the results obtained using a ceramic hollow fiber membrane contactor (HFMC) with those obtained using a wetted-wall column (WWC) was proposed. The method was successfully applied for the determination of the optimal pore structure to increase the CO2 absorption. To find a relationship between relative RmHFMC in the ceramic HFMCs and its pore characteristics, the method was tested on two ceramic HFMCs prepared by non-solvent induced phase separation method. The pore structures were analyzed by scanning electron microscopy, capillary flow porometry, and gas permeability measurements. The results obtained show that the relative RmHFMC contribution ranged from ∼90 to ∼27% of the overall mass transfer resistance (RoHFMC) and was related to the variation of the pore structure properties. To the best of our knowledge, this is the first study to estimate the relative RmHFMC element of the ceramic HFMC through an experimental comparison with a WWC performed in the same experimental conditions. The proposed method is expected to provide a practical solution for estimating the relative RmHFMC of the ceramic HFMCs.
Qing Li, Jing-Tao Wu, Ying Liu, Xiao-Man Qi, Hong-Guang Jin, Chun Yang, Jun Liu, Guang-Li Li, Quan-Guo He
Published: 25 July 2021
Analytica Chimica Acta, Volume 1170; doi:10.1016/j.aca.2021.338480

Abstract:
Since the discovery of liquid-phase-exfoliated black phosphorus (BP) as a field-effect transistor in 2014, BP, with its 2D layered structure, has attracted significant attention, owing to its anisotropic electroconductivity, tunable direct bandgap, extraordinary surface activity, moderate switching ratio, high hole mobility, good biocompatibility, and biodegradability. Several pioneering research efforts have explored the application of BP in different types of electrochemical sensors. This review summarizes the latest synthesis methods, protection strategies, and electrochemical sensing applications of BP and its derivatives. The typical synthesis methods for BP-based crystals, nanosheets, and quantum dots are discussed in detail; the degradation of BP under ambient conditions is introduced; and state-of-the-art protection methodologies for enhancing BP stability are explored. Various electrochemical sensing applications, including chemically modified electrodes, electrochemiluminescence sensors, enzyme electrodes, electrochemical aptasensors, electrochemical immunosensors, and ion-selective electrodes are discussed in detail, along with the mechanisms of BP functionalization, sensing strategies, and sensing properties. Finally, the major challenges in this field are outlined and future research avenues for BP-based electrochemical sensors are highlighted.
Yue Gu, Linhua Jiang, , Zhenhua Wei, Xing Liu, Mingzhi Guo, Kailun Xia, Lei Chen
Journal of Industrial and Engineering Chemistry, Volume 99, pp 256-263; doi:10.1016/j.jiec.2021.04.039

Abstract:
In this paper, a new series of phase change materials (PCMs) composed of capric acid/ethylene-vinyl acetate/graphene (CA/EVA/GR) were prepared and thermal properties were investigated using molecular dynamics simulation. The composite PCMs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal conductivity measurement. FT-IR, XRD and SEM results manifest that CA can be successfully wrapped by EVA and GR additives, and there is no chemical reaction between CA, EVA and GR. DSC results indicate that adding GR into CA/EVA can result in composite PCMs maintain the high latent heat, while too much GR will cause a significant reduction in latent heat. Thermal conductivity obtained from experimental tests reveal that GR can gradually enhance the thermal conductivity of CA/EVA with increasing dosage of GR. The experimental results of thermal conductivity fall close to that of molecular dynamics (MD) simulation at GR dosages below 1.8 wt%, but the experimental results present a trend which is contrary to MD simulation at higher GR dosages. The mean square displacement (MSD) results manifest that composite PCMs containing 1.8 wt% GR has the highest diffusion coefficient, while higher GR dosage will reduce the diffusion coefficient gradually.
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