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Nano Research 2024年第7期17卷 5914-5921页

作者： chun-Ying Chen Qi-Jie Mo Fu-Zhen Li Hai-Li Song Li zhang MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-Sen UniversityGuangzhou 510006China

Alkene hydrosilylation is one of the most concise and atom-economical methods to synthesize organosilicon ***,we reported the precise immobilization of metal single atoms(M-SAs;M=Ru,Rh,Ir,Pd,Pt,and Au)into a porphyrinic metalorganic framework(MOF)of PCN-222(PCN=porous coordination network),and then applied the resultant MOF composites of M-SAs@PCN-222 to alkene *** solvent-free conditions,Pt-SAs@PCN-222 displayed an especially high catalytic efficiency with the turnover frequency up to 119 s−1 and the maximum turnover number of 906,250 at room *** and theoretical studies revealed that there existed strong interactions between Pt-SAs@PCN-222 and the substrates,which helped to condense the substrates in the cavities of the porous *** density functional theory calculations and molecular dynamics simulations disclosed that PCN-222 could transfer electrons to Pt-SAs to enhance the silane oxidative addition and drive the reaction to proceed smoothly via Chalk–Harrod pathway.

关键词： alkene hydrosilylation single atom catalysts metal-organic frameworks precision chemistry synergistic catalysis

Study on Catalytic Behavior of Iron-based Catalyst with IITP as Electron Donor in the Polymerization of Butadiene

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Chinese Journal of Polymer Science 2024年第5期42卷 612-619,I0007页

作者： Shi-Liang Xu Ying-Nan Zhao Yao Yu Qi Yang Li-Hua Na Heng Liu chun-Yu zhang Xue-Quan zhang Key Laboratory of Advanced Rubber Material Ministry of EducationSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China shandong Provincial College Laboratory of Rubber Material and Engineering School of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Key Lab of Rubber-Plastics Ministry of Education/Shandong Provincial Key Lab of Rubber-plasticsSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China

In this study,a novel iron-based catalyst system,Fe(acac)3/(isocyanoimino)triptenylphosphorane(IITP)/AlR3,was employed for the synthesis of syndiotactic 1,2-polybutadiene in *** catalyst system exhibits remarkably high catalytic activity,achieving a polymerization activity of 762 kgpolymer·molcatalyst^(-1)·h^(-1)at 50℃with a[BD]/[Fe]molar ratio of ***,living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene *** characteristics were well demonstrated by a narrow molecular weight distribution(PDI≈2.0)of the resulting polybutadiene and a linear relationship between-ln(1-c)and polymerization time as well as number average molecular weight and polymer *** resultant polymer showed a 1,2-selectivity of approximately 76%and stereoregularity ranging from 62%to 73%(rrrr).Additionally,through kinetic studies on polymerization reaction,an apparent activation energy Ea value of this catalytic system was calculated to be 84.98 kJ·mol^(-1),which suggests that high polymerization temperature favors efficient polymerization.

关键词： Iron catalyst Syndiotactic 1,2-polybutadiene Elastomers Donor Selectivity

The influence of yttrium and manganese additions on the degradation and biocompatibility of magnesium-zinc-based alloys:In vitro and in vivo studies

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Journal of Magnesium and Alloys 2024年第2期12卷 608-624页

作者： Lei Shi Yang Yan chun-sheng Shao Kun Yu Bo zhang Liang-jian Chen Third Xiangya Hospital Central South UniversityChangsha 410013China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China Department of Mechanical Engineering City University of Hong KongHong KongChina

The repair and regeneration of bone defects are highly challenging orthopedic ***,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human *** aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion *** this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a *** then investigated the effect of additions of Y and Mn on alloys'*** results show that Mn and Y can improve not only compression strength but also corrosion *** alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in *** degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or ***,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.

关键词： Magnesium alloy Biodegradation Biocompatibility Bone regeneration Bone defect repair

Locomotion control of a rigid-soft coupled snake robot in multiple environments

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Biomimetic Intelligence & Robotics 2024年第2期4卷 12-23页

作者： Xuanyi Zhou Yuqiu zhang Zhiwei Qiu Zhecheng shan Shibo Cai Guanjun Bao College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China State Key Laboratory of Chemical Engineering College of Chemicaland Bioogical EngineringZhejiang UniverstyHangzhou 310027China College of Biomedical Science and Engineering South China University of TechnologyGuangzhou 510000China

The versatile motion capability of snake robots offers themselves robust adaptability in varieties of challenging environments where traditional robots may be *** study reports a novel flexible snake robot featuring a rigid-flexible coupling structure and multiple motion *** better understand the robot's behavior,a bending model for the soft actuator is ***,a dynamic model is developed to map the relationship between the input air pressure and joint torque,which is the model base for controlling the robot *** on the wave motion generated by the joint coupling direction function in different planes,multiple motion gait planning methods of the snake-like robot are *** order to evaluate the adaptability and maneuverability of the developed snake robot,extensive experiments were conducted in complex *** results demonstrate the robot's effectiveness in navigating through intricate settings,underscoring its potential for applications in various fields.

关键词： Snake robot Rigid-flexible coupled Soft actuator Motion gait analysis

Mechanism of local solidification time variations with melt rate during vacuum arc remelting process of 8Cr4Mo4V high-strength steel

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Journal of Iron and Steel Research International 2024年第2期31卷 377-388页

作者： Tao Pan Hong-chun Zhu Zhou-hua Jiang Hua-bing Li Rui zhang Hao Feng School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

A 2D axisymmetric numerical model was established to investigate the variations of molten pool with different melt rates during the vacuum arc remelting of 8Cr4Mo4V high-strength steel,and the ingot growth was simulated by dynamic mesh *** results show that as the ingot grows,the molten pool profile changes from shallow and flat to V-shaped,and both the molten pool depth and the mushy width ***,the variation of both the molten pool shape and the mushy width melt rate is clarified by the thermal equilibrium *** melt rate increases,both the molten pool depth and the mushy width *** is caused by the increment in sensible heat stored in the ingot due to the limitation of the cooling capacity of the *** nonlinear increment in sensible heat leads to a nonlinear increase in the mushy *** addition,as melt rate increases,the local solidification time(LST)of ingot decreases obviously at first and then *** melt rate is controlled in a suitable range,LST is the lowest and the secondary dendrite arm spacing of the ingot is the smallest,which can effectively improve the compactness degree of 8Cr4Mo4V high-strength steel.

关键词： 8Cr4Mo4V high-strength steel Vacuum arc remelting process Melt rate Molten pool Local solidification time

Modeling Reynolds stress anisotropy invariants via machine learning

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Acta Mechanica Sinica 2024年第6期40卷 50-63页

作者： Xianglin shan Xuxiang Sun Wenbo Cao Weiwei zhang Zhenhua Xia School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China Department of Engineering Mechanics Zhejiang UniversityHangzhou310027China

The presentation and modeling of turbulence anisotropy are crucial for studying large-scale turbulence structures and constructing turbulence ***,accurately capturing anisotropic Reynolds stresses often relies on expensive direct numerical simulations(DNS).Recently,a hot topic in data-driven turbulence modeling is how to acquire accurate Reynolds stresses by the Reynolds-averaged Navier-Stokes(RANS)simulation and a limited amount of data from *** existing studies use mean flow characteristics as the input features of machine learning models to predict high-fidelity Reynolds stresses,but these approaches still lack robust generalization *** this paper,a deep neural network(DNN)is employed to build a model,mapping from tensor invariants of RANS mean flow features to the anisotropy invariants of high-fidelity Reynolds *** the aspects of tensor analysis and input-output feature design,we try to enhance the generalization of the model while preserving invariance.A functional framework of Reynolds stress anisotropy invariants is derived *** irreducible invariants are then constructed from a tensor group,serving as alternative input features for ***,we propose a feature selection method based on the Fourier transform of periodic *** results demonstrate that the data-driven model achieves a high level of accuracy in predicting turbulence anisotropy of flows over periodic hills and converging-diverging ***,the well-trained model exhibits strong generalization capabilities concerning various shapes and higher Reynolds *** approach can also provide valuable insights for feature selection and data generation for data-driven turbulence models.

关键词： Reynolds stress Anisotropy invariant Tensor analysis Machine learning

Towards full-stack deep learning-empowered data processing pipeline for synchrotron tomography experiments

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The Innovation 2024年第1期5卷 127-138页

作者： Zhen zhang chun Li Wenhui Wang Zheng Dong Gongfa Liu Yuhui Dong Yi zhang National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Synchrotron tomography experiments are transitioning into multifunctional,cross-scale,and dynamic characterizations,enabled by new-generation synchrotron light sources and fast developments in beamline ***,with the spatial and temporal resolving power entering a new era,this transition generates vast amounts of data,which imposes a significant burden on the data processing ***,as a highly accurate and efficient data processing method,deep learning shows great potential to address the big data challenge being encountered at future synchrotron *** this review,we discuss recent advances employing deep learning at different stages of the synchrotron tomography data processing *** also highlight how applications in other data-intensive fields,such as medical imaging and electron tomography,can be migrated to synchrotron ***,we provide our thoughts on possible challenges and opportunities as well as the outlook,envisioning selected deep learning methods,curated big models,and customized learning strategies,all through an intelligent scheduling solution.

关键词： processing pipeline outlook

Community Residents' Heritage Preservation Intentions and Influencing Factors Based on the Extended Theory of Planned Behavior: A Case Study of Historic Districts in Tianjin

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China City Planning Review 2024年第3期33卷 40-50页

作者： zhang Tianjie Tang shan School of Architecture Tianjin UniversityTianjinP.R.China

Community residents are important stakeholders in preserving historic districts. This paper introduces the extended theory of planned behavior to explore the intentions of residents to participate in heritage preservation, and further explains the influencing factors. Seven historic districts in Tianjin are selected as case studies. The results show that the residents' intentions to preserve heritage are positively influenced by three subjective perception factors of heritage preservation attitude, subjective norms, and perceived behavioral control, as well as two objective situational factors of environmental quality of historic district and policy guidance for heritage preservation. Furthermore, the objective situational factors indirectly influence heritage preservation intentions through the subjective perception factors. Based on these findings, this paper puts forward corresponding suggestions to enhance the heritage preservation intentions of community residents.

关键词： theory of planned behavior community residents heritage preservation intention historic districts in Tianjin

Constructing highly safe and long-life calcium ion batteries based on hydratedvanadium oxide cathodes featuring a pillar structure

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Rare Metals 2024年第6期43卷 2597-2612页

作者： chun-Fang Wang Shi-Wei zhang Lan Huang Yuan-Min Zhu Feng Liu Jian-Chuan Wang Li-Ming Tan chun-Yi Zhi Cui-Ping Han Powder Metallurgy Research Institute Central South UniversityChangsha410083China Songshan Lake Materials Laboratory Dongguan 523808China Research Institute of Interdisciplinary Science and School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Faculty of Materials Science and Energy Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Calcium-ion batteries(CIBs)have generated intense interest due to the growing demand for safer,cheaper,and large-scale energy storage ***,their development is still in its infancy,owing to the lack of suitable cathodes for sustaining reversiblc Ca^(2+)intercalation/***,layered H_(2)V_(3)O_(8)(HVO)with Zn^(2+)pre-insertion(ZHVO)is reported as a high-rate and highly durable cathode material for *** existence of Zn^(2+)and H_(2)O pillars could expand the interlayer spacing up to 1.8 nm,which is favorable for the diffusion of bulky Ca^(2+).The formation of Zn-O bonds facilitates electron transfer and enhances electrical ***,the ZHVO cathode achieves superior capacity performance(213.9 mAh·g^(-1)at 0.2 A·g^(-1))and long lifespan(78.3%for 1,000 cycles at 5 A·g^(-1))compared to pristine *** functional theory(DFT)calculations revealed that Zn^(2+)moved during Ca^(2+)intercalation,thereby reducing the diffusion energy barrier and facilitating Ca^(2+)***,a safe aqueous calcium ion cell was successfully assembled.

关键词： Multivalent batteries Calcium-ion batteries Layered structure Vanadium oxide Cathode materials

Unique polysulfide reaction on VO_(2) for restraining shuttle effect in soft-packaged Li-S pouch cells

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Rare Metals 2024年第6期43卷 2842-2850页

作者： Ruo-Xuan Yang Qing-chun zhang Jing-Sheng Cai Xuan Cao Qin Yang Ying-Ze Song Wei zhang State Key Laboratory of Environment-Friendly Energy Materials Tianfu Institute of Research and InnovationSchool of Materials and ChemistrySouthwest University of Science and TechnologyMianyang 621010China School of Materials Engineering Changshu Institute of TechnologyChangshu 215500China Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China

The shuttle phenomenon and retarded conversion kinetics of lithium poly sulfides(LiPSs)are relatively severe in lithium-sulfur(Li-S)pouch *** to their redox potential in the sulfur working window,VO_(2)nanobelts show ... 详细信息

关键词： mechanism sulfide lithium