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Ultrafast micro/nano-manufacturing of metastable materials for energy

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National Science Review 2024年第4期11卷 283-298页

作者： Xiaoya Cui Yanchang Liu Yanan Chen School of Materials Science and Engineering Key Laboratory of Advanced Ceramics and Machining Technology(Ministry of Education) and Tianjin Key Laboratory of Composite and Functional MaterialsTianjin University ministry of education key laboratory of Protein Sciences School of Life SciencesTsinghua University

The structural engineering of metastable nanomaterials with abundant defects has attracted much attention in energy-related fields. The high-temperature shock(HTS) technique, as a rapidly developing and advanced synthesis strategy, offers significant potential for the rational design and fabrication of high-quality nanocatalysts in an ultrafast, scalable, controllable and eco-friendly way. In this review, we provide an overview of various metastable micro-and nanomaterials synthesized via HTS, including single metallic and bimetallic nanostructures, high entropy alloys, metal compounds(e.g. metal oxides) and carbon nanomaterials. Note that HTS provides a new research dimension for nanostructures, i.e. kinetic modulation. Furthermore, we summarize the application of HTS—as supporting films for transmission electron microscopy grids—in the structural engineering of 2D materials, which is vital for the direct imaging of metastable materials. Finally, we discuss the potential future applications of high-throughput and liquid-phase HTS strategies for non-equilibrium micro/nano-manufacturing beyond energy-related *** is believed that this emerging research field will bring new opportunities to the development of nanoscience and nanotechnology in both fundamental and practical aspects.

关键词： high-temperature shock technique defect engineering metastable phase kinetic modulation non-equilibrium micro/nano-manufacturing

Integrated multi-scale approach combining global homogenization and local refinement for multi-field analysis of high-temperature superconducting composite magnets

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 747-762页

作者： Hanxiao GUO Peifeng GAO Xingzhe WANG key laboratory of Mechanics on Western Disaster and Environment of ministry of education Key Laboratory of Special Function Materials and Structure Design of Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting *** respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic *** numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally ***,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake *** approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic *** then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic *** results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and *** proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.

关键词： epoxy-impregnated high-temperature superconducting(HTS)magnet multi-scale method global homogenization(GH) local refinement(LR) multi-field analysis

Recent advances in protein conformation sampling by combining machine learning with molecular simulation

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Chinese Physics B 2024年第3期33卷 80-87页

作者：唐一鸣杨中元姚逸飞周运谈圆王子超潘瞳熊瑞孙俊力韦广红 Department of Physics State Key Laboratory of Surface Physicsand Key Laboratory for Computational Physical Sciences (Ministry of Education)Shanghai 200438China

The rapid advancement and broad application of machine learning(ML)have driven a groundbreaking revolution in computational *** of the most cutting-edge and important applications of ML is its integration with molecular simulations to improve the sampling efficiency of the vast conformational space of large *** review focuses on recent studies that utilize ML-based techniques in the exploration of protein conformational *** first highlight the recent development of ML-aided enhanced sampling methods,including heuristic algorithms and neural networks that are designed to refine the selection of reaction coordinates for the construction of bias potential,or facilitate the exploration of the unsampled region of the energy ***,we review the development of autoencoder based methods that combine molecular simulations and deep learning to expand the search for protein ***,we discuss the cutting-edge methodologies for the one-shot generation of protein conformations with precise Boltzmann ***,this review demonstrates the promising potential of machine learning in revolutionizing our insight into the complex conformational ensembles of proteins.

关键词： machine learning molecular simulation protein conformational space enhanced sampling

Investigation of mechanical and electrical characteristics of selfsensing pneumatic torsional actuators

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Science China(Technological Sciences) 2024年第1期67卷 130-142页

作者： XIAO Wei HU DeAn HU GuoLiang XIAO YiHua key laboratory of Conveyance and Equipment Ministry of EducationEast China Jiaotong UniversityNanchang 330013China key laboratory of Advanced Design and Simulation Techniques for Special Equipment Ministry of EducationHunan UniversityChangsha 410082China

Soft pneumatic actuators are one of the most promising actuation for soft robots,and great achievements have been *** it remains challenging to endow sensing capabilities to pneumatic actuators,especially for the sensing ability originating directly from the actuator ***,a self-sensing pneumatic torsional actuator(SPTA)is designed based on the electromagnetic induction effect and magnetically responsive *** SPTA can generate feedback voltage and current with the deformation,in which the sensing function comes from its inherent *** investigate the mechanical and electrical characteristics,an experimental platform and a finite element model are established,*** find that the torsion angle and output torque increase in nonlinear with the actuating *** maximum torsion angle is 66.35°,which is 84.34%of that for the actuator fabricated by pure *** maximum output torque(24.9 N mm)improves by 23.19%compared with the actuator made by pure *** regards the electrical characteristics,the maximum feedback voltage and current are 2.90μV and 29.50 nA when the SPTA is actuated by a pressure of−40 *** also demonstrate that the relationship between the torsion angle and the magnetic flux change is approximately ***,the number of turns of wires,magnetic powders contents,and magnetic direction on the feedback voltage and current are *** show that the feedback voltage and current can be enhanced by increasing the number of turns and magnetic powders *** envision that the SPTA would be promising for soft robots to realize their accuracy control and intelligentization.

关键词： pneumatic torsional actuators self-sensing feedback voltage finite element modeling soft robots

Cross-linkedα-amylase aggregates on Fe3O4 magnetic nanoparticles modified with polydopamine/polyethyleneimine for efficient hydrolysis of starch

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Particuology 2024年第7期90卷 98-105页

作者： Jiandong Cui Xiuming Tang Qingqing Ma Yuyan Chang Qunli Zhang Shiru Jia State key laboratory of Food Nutrition and Safety Laboratory of Industrial Fermentation MicrobiologyMinistry of EducationTianjin University of Science and TechnologyTianjin 300457China key laboratory of Biomass Chemical Engineering of ministry of education Zhejiang UniversityHangzhou 310027China

In this workα-amylase was immobilized on magnetic Fe3O4 nanoparticles with polyethylenimine(PEI)/polydopamine(PDA)coating or 3-aminopropyl triethoxysilane(APTES)for the first time via adsorption–precipitation–*** with the freeα-amylase,the resultant magnetic cross-linkedα-amylase aggregates(PEI/PDA-M-CLEAs and N-M-CLEAs)exhibited excellent thermal and storage stability as well as pH *** storage at 25°C for 60 days,freeα-amylase only retained 60%of its initial activity,while PEI/PDA-M-CLEAs and N-M-CLEAs retained 80%and 78%of their initial activities,***,N-M-CLEAs and PEI/PDA-M-CLEAs showed good *** 6 repeated uses,PEI/PDA-M-CLEAs and N-M-CLEAs still maintained 65%and 62%of their initial activities,***,PEI/PDA-M-CLEAs and N-M-CLEAs exhibited higher starch hydrolysis efficiency than freeα-*** maximum dextrose equivalent(DE)values of starch hydrolysis by PEI/PDA-M-CLEAs and N-M-CLEAs reached 29.24%and 28.79%within 90 min,***,the maximum DE values of starch hydrolysis by the freeα-amylase was only 27.89%even in 150 *** magnetic cross-linkedα-amylase aggregates could be introduced as effective biocatalyst for industrial applications in production of maltose syrups.

关键词： α-amylase Magnetic nanoparticles Functional modification Magnetic cross-linked enzyme aggregates Hydrolysis of starch

Effect of mechanical stresses on degradation behavior of high-purity magnesium in bone environments

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Journal of Materials Science & Technology 2024年第4期171卷 252-261页

作者： Yan Yao Jie Xia Lizhen Wang Yuanming Gao Xili Ding Chao Wang Yubo Fan key laboratory of biomechanics and Mechanobiology(Beihang University) Ministry of EducationBeijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringSchool of Engineering MedicineBeihang UniversityBeijing 100083China

High-purity(HP)magnesium(Mg)has emerged as a promising biomaterial for supporting functional bone *** previous study found that mechanical stresses and the surrounding fibrotic tissue(subcuta-neous)both play crucial roles in the degradation of HP ***,due to challenges in the degradation and regeneration process in vivo,it remains unclear how stress affects HP Mg degradation in bone en-vironments,limiting its further *** this study,novel loading devices were designed and the effects of tensile and compressive stresses on HP Mg degradation in vivo and in vitro bone environments were quantitatively *** addition,bone osteointegration around HP Mg was explored *** stress increases the degradation rate of HP Mg in vivo and in *** Mg degradation in vivo is more sensitive to stress factors than in vitro,but the sensitivity decreases with corrosion *** volume loss rate of HP Mg is multilinear with the applied stress and degradation *** volume of bone tissue surrounding HP Mg is larger in the no-stress group compared to the stressed groups,which is more pronounced with increasing implantation *** results provide valuable insights for optimiz-ing the design of HP Mg-based implants considering load *** will help to achieve a balance between the degradation rate of the implant and the regeneration rate of the surrounding bone.

关键词： High-purity magnesium Quantitative stresses Degradation Bone environments In vivo and in vitro

Application of surfactant for improving leaching process of weathered crust elution-deposited rare earth ores

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Journal of Rare Earths 2024年第1期42卷 181-190,I0007页

作者： Fang Zhou Lisen Zhang Zhiwei Wang Yixin Zhang Ru'an Chi Xiaoyan Wu key laboratory for Green Chemical Process of ministry of education Wuhan Institute of TechnologyWuhan430073China

Weathered crust elution-deposited rare earth ores(WREOs)in China are the main source of medium and heavy rare earths in the *** order to improve the seepage and the mass transfer of traditional ammonium salt leaching process of WREOs,surfactants were added in the ammonium sulfate leaching solution and the ammonium chloride leaching *** leaching kinetics,the mass transfer process,and the adhesion work reduction factor calculated from the interfacial properties were studied to reveal the strengthening mechanism of *** the presence of the tested five surfactants,cetyl trimethyl ammonium bromide(CTAB),dodecyl trimethyl ammonium bromide(DTAB),sodium dodecyl sulfate(SDS),sodium oleate and oleic acid,the permeability of WREOs is improved,the rare earth(RE)leaching efficiency increase and the impurity aluminum(Al)leaching efficiency decrease,indicating its promotional effect on the leaching process of ***,CTAB shows a better leaching enhancement,and the optimal addition dosage is 0.4 g/L for the two ammonium salt leaching agent *** kinetics analysis shows the internal diffusion controls model of RE and Al leaching process,and the leaching kinetics equations of RE and Al related to CTAB concentration were obtained for the two ammonium salt leaching *** to the chromatographic plate theory,the mass transfer efficiency of RE increases with the CTAB concentration increasing until 0.4 g/L,which confirms that the optimal CTAB addition is 0.4 g/*** adhesion work and adhesion work reduction factor indicate more favorable permeation as well as the leaching process.

关键词： Weathered crust elution-deposited rare earth ores Surfactant Kinetics Mass transfer

Particle residence time distribution and axial dispersion coefficient in a pressurized circulating fluidized bed by using multiphase particle-in-cell simulation

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Chinese Journal of Chemical Engineering 2024年第5期69卷 167-176页

作者： Jinnan Guo Daoyin Liu Jiliang Ma Cai Liang Xiaoping Chen key laboratory of Energy Thermal Conversion and Control of ministry of education Southeast UniversityNanjing 210096China

The particle residence time distribution(RTD)and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed(PCFB).In this study,the effects of pressure(0.1-0.6 MPa),fluidizing gas velocity(2-7 m·s^(-1)),and solid circulation rate(10-90 kg·m^(-2)·s^(-1))on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell(MP-PIC)*** details of the gas-solid flow behaviors of PCFB are *** on the gas-solid flow pattern,the particles tend to move more orderly under elevated *** an increase in either fluidizing gas velocity or solid circulation rate,the mean residence time of particles decreases while the axial dispersion coefficient *** an increase in pressure,the core-annulus flow is strengthened,which leads to a wider shape of the particle RTD curve and a larger mean particle residence *** back-mixing of particles increases with increasing pressure,resulting in an increase in the axial dispersion coefficient.

关键词： Pressurized circulating fluidized bed MP-PIC method Residence time distribution Axial dispersion coefficient

In situ embedded bismuth nanoparticles among highly porous carbon fibers for efficient carbon dioxide reduction

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Rare Metals 2024年第9期43卷 4312-4320页

作者： Wei-Jian Guo Ao Zhou Wen-Wen Cai Jin-Tao Zhang key laboratory for Colloid and Interface Chemistry (ministry of education) School of Chemistry and Chemical EngineeringShandong University

Electrocatalysis provides an optimal approach for the conversion of carbon dioxide(CO2) into high-value chemicals, thereby presenting a promising avenue toward achieve carbon neutrality. However, addressing the selectivity and stability challenges of metal catalysts in electrolytic reduction remains a daunting task. In this study, the electrospinning method is employed to fabricate porous carbon nanofibers loaded with bismuth nanoparticles with the help of in situ pyrolysis. The porous carbon nanofibers as conductive support would facilitate the dispersion of bismuth active sites while inhibiting their aggregation and promoting the mass transfer, thus enhancing their electrocatalytic activity and stability. Additionally, nitrogen doping induces electron delocalization in bismuth atoms through metal-support interactions, thus enabling efficient adsorption of intermediates for improving selectivity based on the theoretical calculation. Consequently, Bi@PCNF-500 exhibits the exceptional selectivity and stability across a wide range of potential windows. Notably, its faradaic efficiency(FE) of formate reaches 92.7% in H-cell and94.9% in flow cell, respectively, with good electrocatalytic stability. The in situ characterization and theoretical calculations elucidate the plausible reaction mechanism to obtain basic rules for designing efficient electrocatalyst.

关键词： Carbon dioxide reduction Electron delocalization N-doping Porous carbon nanofiber