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Integrated high-performance and accurate shaping technology of low-cost powder metallurgy titanium alloys: A comprehensive review

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 413-426页

作者： Xuemeng Gan Shaofu Li Shunyuan Xiao Yafeng Yang State Key Laboratory of Mesoscience and engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Science and technology on Particle Materials Chinese Academy of SciencesBeijing 100190China

The practical engineering applications of powder metallurgy (PM) Ti alloys produced through cold compaction and pressure-less sintering are impeded by poor sintering densification, embrittlement caused by excessive O impurities, and severe sintering deforma-tion resulting from the use of heterogeneous powder mixtures. This review presents a summary of our previous work on addressing the above challenges. Initially, we proposed a novel strategy using reaction-induced liquid phases to enhance sintering densification. Near- complete density (relative density exceeding 99%) was achieved by applying the above strategy and newly developed sintering aids. By focusing on the O-induced embrittlement issue, we determined the onset dissolution temperature of oxide films in the Ti matrix. On the basis of this finding, we established a design criterion for effective O scavengers that require reaction with oxide films before their dissol-ution. Consequently, a ductile PM Ti alloy was successfully obtained by introducing 0.3wt% NdB6 as the O scavenger. Lastly, a powder- coating strategy was adopted to address the sintering deformation issue. The ultrafine size and shell-like distribution characteristics of coating particles ensured rapid dissolution and homogeneity in the Ti matrix, thereby facilitating linear shrinkage during sintering. As a result, geometrically complex Ti alloy parts with high dimensional accuracy were fabricated by using the coated powder. Our fundament-al findings and related technical achievements enabled the development of an integrated production technology for the high-performance and accurate shaping of low-cost PM Ti alloys. Additionally, the primary engineering applications and progress in the industrialization practice of our developed technology are introduced in this review.

关键词： powder metallurgy titanium sintering densification oxygen scavenging accurate shaping

Continuous advantage learning for minimum-time trajectory planning of autonomous vehicles

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Science China(Information Sciences) 2024年第7期67卷 285-294页

作者： Zhuo LI Weiran WU Jialin WANG Gang WANG Jian SUN School of Automation Beijing Institute of Technology Beijing institute of technology Chongqing Innovation Center China Academy of Launch Vehicle technology Intelligent Game and Decision Laboratory

This paper investigates the minimum-time trajectory planning problem of an autonomous vehicle. To deal with unknown and uncertain dynamics of the vehicle, the trajectory planning problem is modeled as a Markov decision process with a continuous action space. To solve it, we propose a continuous advantage learning(CAL) algorithm based on the advantage-value equation, and adopt a stochastic policy in the form of multivariate Gaussian distribution to encourage exploration. A shared actor-critic architecture is designed to simultaneously approximate the stochastic policy and the value function, which greatly reduces the computation burden compared to general actor-critic methods. Moreover, the shared actor-critic is updated with a loss function built as mean square consistency error of the advantage-value equation, and the update step is performed several times at each time step to improve data efficiency. Simulations validate the effectiveness of the proposed CAL algorithm and its better performance than the soft actor-critic algorithm.

关键词： trajectory planning continuous advantage learning stochastic policy shared actor-critic

Electrodeposition of rare refractory metals in low-temperature ionic liquids

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Rare Metals 2024年第10期43卷 4921-4933页

作者： Lin-Lin Wang Han-Dong Jiao Rui Yuan Le-Yang Li Man-Peng Lin Rui-Yang Sun Jiu-San Xiao Shu-Qiang Jiao institute of Advanced Structure technology Beijing Institute of Technology State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Rare refractory metals(RRMs) play a significant role in fundamental industries, including electronics,chemical industry, machinery, etc., and future advanced fields, such as aerospace and superconductivity. However,the traditional production processes of RRMs based on high-temperature thermal reduction cannot meet the requirements of low-energy consumption. This dilemma could be addressed efficiently by using a low-temperature electrodeposition strategy in ionic liquids(ILs). This review summarizes a panoramic view of the latest developments on the electrodeposition of RRMs in ILs after a brief review on the current industrial production methods of RRMs. Based on this, the electrochemical mechanism occurring at the cathode during the electrodeposition process of RRMs in different electrolytes and under different conditions is thoroughly discussed, because it is crucial for the successful production of pure RRMs. In addition, this review not only analyses the main challenges that hinder the industrial application of the electrodeposition of RRMs in ILs, but also proposes corresponding solutions. We hope this review can provide a valuable guidance for the fundamental research and industrial development of lowtemperature electrodeposition of RRMs.

关键词： Chemical industry

Electrocatalytic NAD(P)H regeneration for biosynthesis

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Green Chemical engineering 2024年第1期5卷 1-15页

作者： Yaoxuan Li Guanhua Liu Weixi Kong Suoqing Zhang Yuemei Bao Hao Zhao Lihui Wang Liya Zhou Yanjun Jiang National-Local Joint engineering Laboratory for Energy Conservation in Chemical process Integration and Resources Utilization School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin300401China North China Pharmaceutical Group Corp Shijiazhuang050015China Tianjin Food Research institute Tianjin301609China

The highly efficient chemoselectivity,stereoselectivity,and regioselectivity render enzyme catalysis an ideal pathway for the synthesis of various chemicals in broad *** the cofactor of an enzyme is necessary but expensive,the conversed state of the cofactor is not beneficial for the positive direction of the *** regeneration using electrochemical methods has the advantages of simple operation,low cost,easy process monitoring,and easy product separation,and the electrical energy is green and ***,bioelectrocatalysis has great potential in synthesis by combining electrochemical cofactor regeneration with enzymatic *** this review,we detail the mechanism of cofactor regeneration and categorize the common electron mediators and enzymes used in cofactor *** reaction type and the recent progress are summarized in electrochemically coupled enzymatic *** main challenges of such electroenzymatic catalysis are pointed out and future developments in this field are foreseen.

关键词： Biosynthesis Cofactor regeneration Bioelectrocatalysis NAD(P)H Electron mediator

Development of biomedical hydrogels for rheumatoid arthritis treatment

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Asian Journal of Pharmaceutical Sciences 2024年第1期19卷 35-48页

作者： Mirza Muhammad Faran Ashraf Baig Lee KiWong Abdul Wasy Zia Hongkai Wu Department of Chemistry Hong Kong University of Science and TechnologyHong Kong 999077China institute of Mechanical Process and Energy Engineering(IMPEE)School of Engineering and Physical SciencesHeriot-Watt UniversityEdinburghUnited Kingdom

Rheumatoid Arthritis(RA)is an autoimmune disorder that hinders the normal functioning of bones and joints and reduces the quality of human *** year,millions of people are diagnosed with RA worldwide,particularly among elderly individuals and ***,there is a global need to develop new biomaterials,medicines and therapeutic methods for treating *** will improve the Healthcare Access and Quality Index and also relieve administrative and financial burdens on healthcare service providers at a global *** are soft and cross-linked polymeric materials that can store a chunk of fluids,drugs and biomolecules for hydration and therapeutic *** are biocompatible and exhibit excellent mechanical properties,such as providing elastic cushions to articulating joints by mimicking the natural synovial ***,hydrogels create a natural biological environment within the synovial cavity to reduce autoimmune reactions and *** also lubricate the articulating joint surfaces to prevent degradation of synovial surfaces of bones and cartilage,thus exhibiting high potential for treating *** work reviews the progress in injectable and implantable hydrogels,synthesis methods,types of drugs,advantages and ***,it discusses the role of hydrogels in targeted drug delivery,mechanistic behaviour and tribological performance for RA treatment.

关键词： Rheumatoid arthritis Orthopeadic joints Hydrogel Therapeutics Mechanical properties Medicine

Energy budget of cold and hot gas-solid fluidized beds through CFD-DEM simulations

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Particuology 2024年第6期89卷 153-171页

作者： Lei Bi Yunpeng Jiao Chunjiang Liu Jianhua Chen Wei Ge School of Chemical engineering and technology Tianjin UniversityTianjin 300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical engineering University of Chinese Academy of SciencesBeijing 100049China

Direct energy budget is carried out for both cold and hot flow in gas–solid fluidization ***,the energy paths are proposed from thermodynamic *** consumption means total power input to the specific system,and it can be decomposed into energy retention and energy *** retention is the variation of accumulated mechanical energy in the system,and energy dissipation is the energy converted to heat by irreversible *** based on the Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)framework,different energy terms are quantified from the specific flow elements of fluid cells and particles as well as their interactions with the *** order to clarify the energy budget,it is important to identify which system is studied:the particle-fluid system or the particle *** the cold flow,the total energy consumption of the particle sub-system can well indicate the onset of bubbling and turbulent,while the variation of local energy consumption terms can reflect the evolution of heterogeneous *** the hot flow,different heat transfer mechanisms are analyzed and the solver is modified to reproduce the experimental *** impact of the heat transfer mechanisms and heat production on energy consumption is also *** proposed budget method has proven to be energy-conservative and easy to conduct,and it is hopeful to be applied to other multiphase flow systems.

关键词： Energy budget Gas-solid fluidization CFD-DEM Regime transition Heat transfer mechanism

Steering the energy sharing of electrons in nonsequential double ionization with orthogonally polarized two-color field

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Chinese Physics B 2024年第8期33卷 248-252页

作者：樊光琦杨志杰孙烽豪郑金梅韩云天黄明谦刘情操 College of Science Harbin Institute of TechnologyWeihai 264209China School of Information Science and engineering Harbin Institute of TechnologyWeihai 264209China Harbin institute of technology Weihai 264209China

Using the semiclassical ensemble model,the dependence of relative amplitude for the recollision dynamics in nonsequential double ionization(NSDI)of neon atom driven by the orthogonally polarized two-color field(OTC)laser field is theoretically *** the dynamics in two typical collision pathways,recollision-impact-ionization(RII)and recollisionexcitation with subsequent ionization(RESI),is systematically *** results reveal that the V-shaped structure in the correlated momentum distribution is mainly caused by the RII mechanism when the relative amplitude of the OTC laser field is zero,and the first ionized electrons will quickly skim through the nucleus and share few energy with the second *** the relative amplitude increases,the V-shaped structure gradually disappears and electrons are concentrated on the diagonal in the electron correlation spectrum,indicating that the energy sharing after electrons collision is symmetric for OTC laser fields with large relative *** studies show that changing the relative amplitude of the OTC laser field can efficiently control the electron–electron collisions and energy exchange efficiency in the NSDI process.

关键词： nonsequential double ionization correlated electron–electron momentum distribution energy sharing of electrons orthogonally polarized two-color field laser field semiclassical ensemble models

Microscale spherical TiO_(2)powder prepared by hydrolysis of TiCl_(4)solution:Synthesis and kinetics

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Particuology 2024年第1期84卷 60-71页

作者： Peiyi Yan Ying Zhang Shili Zheng School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Key Laboratory of Green process and engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization Panzhihua617000China

Hydrolysis of TiCl_(4)solution is capable of preparing microscale TiO_(2)*** research studied the synthesis of microscale spherical TiO_(2)powders and the hydrolysis *** effects of the flow field generated by different agitators and baffles in the crystallizer,the initial free acid concentration,the initial equivalent TiO_(2)concentration,and the temperature on the hydrolysis progress and powder morphology were systematically *** results show that the flow field in a crystallizer can significantly affect the morphology and particle size of the powders,and the axial flow can improve the sphericity of the *** increased free HCl and equivalent TiO_(2)concentrations in the pregnant solution inhibit the forward hydrolysis reaction,prolong the time to reach equilibrium,and reduce the *** appropriate temperature matching the compositions of the pregnant solution is crucial for the powder morphology and *** with sizes ranging from around 5 um-40μm can be tuned under controlled flow field,solution compositions,and temperature *** addition,the Cheng.and Wunderlich modified Avrami equation was used for the crystallization kinetic *** effects of the free HCl concentration,equivalent TiO_(2)concentration,and hydrolysis temperature are reflected in the reaction rate constant and active nuclei reduction *** the free HCl and equivalent TiO_(2)concentrations will reduce the reaction rate constant and accelerate the deactivation of the active nuclei,thus increasing the final powder size,while increasing the temperature will lead to the opposite results.

关键词： TiCl_(4) Hydrolysis Microscale TiO_(2) Spherical Kinetics

Ionic liquids inhibit the dynamic transition fromα-helices toβ-sheets in peptides

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Fundamental Research 2024年第4期4卷 777-784页

作者： Ju Liu Yanlei Wang Feng Huo Hongyan He Beijing Key Laboratory of Ionic Liquids Clean process State Key Laboratory of Mesoscience and EngineeringCAS Key Laboratory of Green Process and EngineeringInstituteof Process EngineeringChineseAcademyof SciencesBeijing100190China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial TechnologyHenan UniversityZhengzhou 450000China University of Chinese Academyof Sciences Beijing100049China

Abnormalities in the transition betweenα-helices andβ-sheets(α-βtransition)may lead to devastating neurodegenerative diseases,such as Parkinson's syndrome and Alzheimer's *** liquids(ILs)are potential drugs for targeted therapies against these diseases because of their excellent bioactivity and designability of ***,the mechanism through which ILs regulate the aα-βtransition remains ***,a combination of GPU-accelerated microsecond molecular dynamics simulations,correlation analysis,and machine learning was used to probe the dynamicalα-βtransition process induced by ILs of 1-alkyl-3-methylimidazolium chloride([C_(n)mim]cl)and its molecular ***,the cation of [C_(n)mim]+in ILs can spontaneously insert into the peptides as free ions(n≤10)and clusters(n≥11).Such insertion can significantly inhibit theα-β,transition and the inhibiting ability for the clusters is more significant than that of free ions,where[Ciomim]+and[C_(12)mim]+can reduce the maximumβ-sheet content of the peptide by 18.5% and 44.9%,***,the correlation analysis and machine learning method were used to develop a predictive model accounting for the influencing factors on theα-βtransition,which could accurately predict the effect of ILs on theα-β***,these quantitative results may not only deepen the understanding of the role of ILs in theα-βtransition but also guide the development of the IL-based treatments for related diseases.

关键词： α-βtransition Moleculardynamics simulation lonic liquids Machine learning Membrane channel protein