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Sigmatropic rearrangements of B(MIDA)-propargylic alcohols towards the diverse synthesis of α-functionalized organoborons

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Science China Chemistry 2024年第2期67卷 568-575页

作者： Jiasheng Qian Li-cai Liu zhi-hao Chen Yuan Liu Yin Li Qingjiang Li Honggen Wang Guangdong Key Laboratory of Chiral Molecule and Drug Discovery School of Pharmaceutical SciencesSun Yat-Sen UniversityGuangzhou510006China

α-Functionalized organoborons are useful building blocks and key structural elements in functional *** previous synthesis relied on the famous Matteson reaction or the late-stage borylative modification of alkynes or ***,the synthetic transformation of borylated building blocks offers another useful strategy and is currently actively *** report herein that B(MIDA)-propargylic alcohols(BPAs) are a useful type of borylated building *** two complementary functional group handles(alkyne and hydroxyl) in close proximity,the redox-neutral [3,3] and [2,3] sigmatropic rearrangements of BPAs allow the efficient synthesis of several types of α-functionalized boronates,including α,β-unsaturated acylborons,α-S/P-substituted allenylborons,boryl-substituted thiazoles and a borylated α,β-unsaturated hydrazine,some of which are otherwise challenging targets using other synthetic methods.

关键词： organoboron diverse synthesis sigmatropic rearrangement heteroarene amide

P-symmetric Subharmonic Solutions for Nonlinear Hamiltonian Systems

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1388-1408页

作者： Duan zhi ZHANG zhi hao Zhao School of Mathematical Sciences Nankai UniversityTianjin 300071P.R.China

In this paper,we prove that for each positive k≡1 mod m there exists a P-symmetric kmτ-periodic solution xk for asymptotically linear mτ-periodic Hamiltonian systems,which are nonautonomous and endowed with a *** the P-symmetric Hamiltonian function is semi-positive,one can prove,under a new iteration inequality of the Maslov-type P-index,that xk_(1) and xk_(2) are geometrically distinct for k_(1)/k_(2)≥(2n+1)m+1;and xk_(1),xk_(2) are geometrically distinct for k_(1)/k_(2)≥m+1 provided xk_(1) is non-degenerate.

关键词： P-symmetric subharmonic Hamiltonian systems Maslov-type index theory iteration inequality asymptotically linear

Grain-boundary segregation and grain growth in nanocrystalline substitutional solid solution alloys

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Journal of Materials Science & Technology 2024年第1期168卷 239-249页

作者： Fawei Tang Chao Hou hao Lu zhi Zhao Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were *** on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been *** study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.

关键词： Substitutional solid solution Grain boundary segregation Thermal stabilization Solute concentration Grain size

Multi-scale hash encoding based neural geometry representation

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Computational Visual Media 2024年第3期10卷 453-470页

作者： zhi Deng haoyao Xiao Yining Lang hao Feng Juyong Zhang School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China Alibaba Artiﬁcial Intelligence Governance Laboratory Alibaba GroupHangzhou 310017China

Recently, neural implicit function-basedrepresentation has attracted more and more attention,and has been widely used to represent surfacesusing differentiable neural networks. However, surfacereconstruction from point clouds or multi-view imagesusing existing neural geometry representations stillsuffer from slow computation and poor accuracy. Toalleviate these issues, we propose a multi-scale hashencoding-based neural geometry representation whicheffectively and efficiently represents the surface asa signed distance ﬁeld. Our novel neural networkstructure carefully combines low-frequency Fourierposition encoding with multi-scale hash encoding. Theinitialization of the geometry network and geometryfeatures of the rendering module are accordinglyredesigned. Our experiments demonstrate that theproposed representation is at least 10 times faster forreconstructing point clouds with millions of *** also signiﬁcantly improves speed and accuracyof multi-view reconstruction. Our code and modelsare available at https://***/Dengzhi-USTC/Neural-Geometry-Reconstruction.

关键词： neural geometry representation hash encoding point cloud reconstruction multi-view reconstruction

An Overview of Stretchable Supercapacitors Based on Carbon Nanotube and Graphene

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Chinese Journal of Polymer Science 2020年第5期38卷 491-505,I0006页

作者： Wen-Le Ma zhi-hao cai Yi Zhang Zi-Yuan Wang Lun Xia Su-Ping Ma Guang-hao Li Yi Huang National Institute for Advanced Materials Tianjin Key Laboratory of Metal and Molecule Based Material ChemistryKey Laboratory of Functional Polymer MaterialsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Materials Science and EngineeringNankai UniversityTianjin 300350China Beijing Institute of Aeronautical Materials Beijing 100095China

The wearable demand of modern electronic devices makes flexible and stretchable energy storage device urgently *** and flexible supercapacitors(SCs)are energy storage devices that provide ultrahigh power density while having long-term durability,high security,and electrochemical *** different SCs electrode materials,CNTs and graphene-based materials exhibit great potential in terms of stretchable SCs due to its ultrahigh electrical conductivity,large specific surface area and good mechanical *** this review,the state-of-the-art process and achievements in the field of stretchable SCs enabled by CNTs and graphene are presented,which include the novel design strategy,mechanical and electrochemical *** final section highlights current challenges and future perspectives on research in this thriving field.

关键词： Stretchable Supercapacitors Carbon materials Graphene CNTs

Co_(3)O_(4)as an efficient passive NO_(x) adsorber for emission control during cold-start of diesel engines

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Chinese Journal of Chemical Engineering 2024年第2期66卷 1-7页

作者： Jinhuang cai Shijie hao Yun Zhang Xiaomin Wu Zhenguo Li Huawang Zhao Department of Environmental Science&Engineering College of Chemical EngineeringHuaqiao UniversityXiamen 361021China Wuxi Weifu Environmental Catalysts Co. LtdWuxi 214000China National Engineering Laboratory for Mobile Source Emission Control Technology China Automotive Technology&Research Center Co.Ltd.Tianjin 300300China

The Co_(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to control the cold start emissions from *** nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen,which exhibited a NO_(x) uptake capacity commensurate with Pd/SSZ-13 at 100℃.The primary NO_(x) release temperature falls within a temperature range of 200-350℃,making it perfectly suitable for diesel *** characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation,contributing to the NO_(x) storage at 100℃,while the nitrites begin to decompose within the 150-200℃***,lattice oxygen likely becomes involved in the activation of nitrites into more stable nitrate within this particular temperature *** concurrent processes of nitrites decomposition and its conversion to nitrates results in a minimal NO_(x) release between the temperatures of 150-200℃.The nitrate formed via lattice oxygen mainly induces the NO_(x) to be released as NO_(2) within a temperature range of 200-350℃,which is advantageous in enhancing the NO_(x) activity of downstream NH_(3)-SCR catalysts,by boosting the fast SCR reaction *** to its low cost,considerable NO_(x) absorption capacity,and optimal release temperature,Co_(3)O_(4)demonstrates potential as an effective material for passive NO_(x) adsorber applications.

关键词： Emission control Cold-start Low-temperature adsorption Co_(3)O_(4) Nitrate formation

New insights into the pre-lithiation kinetics of single-crystalline Ni-rich cathodes for long-life Li-ion batteries

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Green Energy & Environment 2024年第3期9卷 556-564页

作者： Qiang Han Lele cai Zhaofeng Yang Yanjie Hu hao Jiang Chunzhong Li Shanghai Engineering Research Center of Hierarchical Nanomaterials School of Chemical EngineeringEast China University of Science and TechnologyShanghai200237China Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and ***,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation *** well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation *** coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full *** enhancement mechanism has also been *** findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.

关键词： Single-crystalline cathode Ni-rich oxides Pre-lithiation Li-ion batteries Surface modification

Security-constrained Transmission Maintenance Optimization Considering Generation and Operational Risk Costs

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 767-781页

作者： Dan Xu zhi cai Qian Cheng Guodong Huang Jingyang Zhou Junjie Tang Beijing Key Laboratory of Research and System Evaluation of Power Dispatching Automation Technology China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China

With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power ***,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed *** model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission ***,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution *** cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment *** electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence *** IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.

关键词： Transmission maintenance security-constrained unit commitment iterative algorithm cost feedback N−1 risk assessment

Interface strengthening for thermal sprayed WC-10Co4Cr coating subjected to pulsed magnetic treatment

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Rare Metals 2024年第2期43卷 780-795页

作者： Cheng-Kai Qian Qu Liu Heng Wang Ke-Jian Li zhi-Peng cai Department of Mechanical Engineering Tsinghua UniversityBeijing100084China Tianjin Research Institute for Advanced Equipment Tsinghua UniversityTianjin300304China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing100084China

The reliability of the coated industry components demands ideal fatigue properties of the coating,and it is mainly determined by the performance of the *** this study,pulsed magnetic treatment(PMT)was applied to the thermal sprayed WC-10Co4Cr coating,and the fatigue lifetime of the coated bolt increased by 219.82%under an imitation of the operating mode *** tests further proved that both the adhesion and cohesion strength were improved after PMT,and they benefit from the interface strengthening *** formation of coherent WC/Co interfaces was characterized by in-situ transmission electron microscopy(TEM),and the molecular dynamic simulations indicate that the work of separation of these interfaces is much higher than the original disordered *** stress was relaxed and distributed more homogeneously after PMT,and it mainly contributes to the coating/substrate *** work provides a new post-treatment method focusing on the interfaces in the WC-based coating and gives insight into its mechanism so that it is hopeful to be applied to other kinds of coatings.

关键词： Cemented carbide coating Pulsed magnetic treatment Interface strengthening Fatigue properties Adhesion strength