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CES Transactions on Electrical Machines and Systems 2023年第1期7卷 11-20页

作者： Tao Li Yongli Li yuchen zhu IEEE the School of Electrical Automation and Information Engineering Tianjin UniversityTianjin300072China CES

For the hybrid multi-infeed HVDC system in which the receiving-end grid is a strong AC grid including LCC-HVDC subsystems and multiple VSC-HVDC subsystems,it has higher voltage support ***,for weak AC grid,the voltage support capability of the multi-VSC-HVDC subsystems to the LCC-HVDC subsystem(voltage support capability-mVSCs-LCC)can resist the risk of commutation *** on this consideration,this paper proposes an evaluation index called Dynamic Voltage Support Strength Factor(DVSF)for the hybrid multi-infeed system,and uses this index to qualitatively judge the voltage support capability-mVSCs-LCC in weak AC *** addition,the proposed evaluation index can also indirectly judge the ability of the LCC-HVDC subsystem to suppress commutation ***,the mathematical model of the power flow of the LCC and VSC networks in the steady-state is analyzed,and the concept of DVSF applied to hybrid multi-infeed system is ***,the DVSF index is also used to qualitatively judge the voltage support ***,the influence of multiple VSC-HVDC subsystems with different operation strategies on the DVSF is analyzed with reference to the concept of ***,the indicators proposed in this paper are compared with other evaluation indicators through MATLAB simulation software to verify its *** importantly,the effects of multi-VSC-HVDC subsystems using different coordinated control strategies on the voltage support capability of the receiving-end LCC-HVDC subsystem are also verified.

关键词： Hybrid multi-infeed HVDC system Voltage support Multi-VSC-HVDC LCC-HVDC Commutation failure DVSF Control strategy

Interface structure and strain controlled Pt nanocrystals grown at side facet of MoS_(2)with critical size

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Nano Research 2022年第9期15卷 8493-8501页

作者： yuchen zhu Yinghui Sun Hongzhou Zhang Yang He Wei Liu Rongming Wang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface ScienceUniversity of Science and Technology BeijingBeijing 100083China School of Physics Trinity College DublinDublin 2D02 PN40Ireland Division of Energy Research Resources Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of Sciences457 Zhongshan RoadDalian 116023China

The heterostructure of transition metal nanocrystal on two-dimensional(2D)materials exhibits unique physical and chemical properties through various interfacial *** has been established that the atomic structure and strain in the vicinity of the interface determine the band structure and phonon modes of the nanocrystal,regulating the optical and electrical properties of such ***,metal–support interfacial engineering is a demonstrated approach to acquiring desired properties of the ***,a fundamental understanding of the interfacial structures remains elusive and precise control of the interactions has yet ***,we explore the regulation of interface on MoS_(2)supported Pt nanocrystals which were prepared by reducing ultrasonic dispersed potassium *** Pt-MoS_(2)heterostructure interface was systematically studied by aberration corrected transmission electron *** types of Pt-MoS_(2)interfaces with distinct atomic configurations were *** strain within the Pt nanocrystals is sensitive to the atomic configuration of the supporting MoS_(2),which regulates the size of the Pt *** results provide insights on tuning of nanocrystal strain,paving the way for precise control of 2D semiconductor heterostructures.

关键词： nucleation crystallization metal-2D semiconductor heterostructure interface interaction

Lateral strain tailoring in manganite homostructures assisted by atomic-flat freestanding membranes

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Nano Research 2023年第5期16卷 7829-7836页

作者： Yufei Wang yuchen zhu Shengru Chen Dongke Rong Qiao Jin Er-Jia Guo College of Materials Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China Department of Physics&Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Complex oxide thin films exhibit intriguing phenomena due to the coupling between multiple degrees of freedom through interfacial structural *** tailoring of structural parameters determines unique band structure and phonon modes,regulating emergent magnetic and electrical properties of oxide ***,the construction of different strained and oriented domains in one intact oxide thin film is impossible using conventional *** we report the fabrication and quantitative structural analysis of La_(0.7)Sr_(0.3)MnO_(3)(LSMO)homostructures assisted by atomic-flat freestanding *** substrates and suspended membranes regulate the epitaxial strain and orientation of subsequently grown *** results demonstrate an ultrathin transition layer(~4 atomic layers)between freestanding membranes and LSMO films is formed due to the strain *** work offers a simple and scalable methodology for fabricating unprecedented innovative functional oxide homostructures through artificially controlled synthesis routes.

关键词： transmission electron microscopy oxide homostructure freestanding membranes manganites strain engineering

Direct observation of epitaxial alignment of Au on M0S2 at atomic resolution

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Nano Research 2019年第4期12卷 947-954页

作者： Yinghui Sun Haofei Zhao Dan Zhou yuchen zhu Huanyu Ye Yan Aung Moe Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science School of Mathematics and Physics University of Science and Technology Beijing Beijing 100083 China Stuttgart Center for Electron Microscopy Max Planck Institute for Solid State Research Stuttgart 70569 Germany

The morphology and structural stability of metal/2D semic on ductor interfaces strongly affect the performa nee of 2D electronic devices and synergistic catalysis. However, the structural evolution at the interfaces has not been well explored particularly at atomic resolution. In this work, we study the structural evoluti on of Au nan oparticles (NPs) on few-layer MoS2 by high resol utio n transmissi on electro n microscopy (HRTEM) an d quan titative high-angle annular dark field seanning TEM. It is found that in the transition of Au from nan oparticles to den drites, a dynamically epitaxial align ment betwee n Au and MoS2 lattices is formed, and Moirc patter ns can be directly observed in HRTEM images due to the mismatch between Au and M0S2 lattices. This epitaxial alignment can occur in ambient conditions, and can also be accelerated by the irradiation of high-energy electron beam. In situ observation clearly reveals the rotation of Au NPs, the atom migration inside Au NPs, and the transfer of Au atoms between neighboring Au NPs, finally leading to the formation of epitaxially aligned Au dendrites on M0S2. The structural evoluti on of metal/2D semico nductor in terfaces at atomic scale can provide valuable information for the design and fabricatio n of the metal/2D semicon ductorn ano-devices with desired physical and chemical performa nces.

关键词： atom migration M0S2 in situ transmission electron microscopy (TEM) metal-semiconductor interface Moire patterns

Gas-discharge induced flash sintering of YSZ ceramics at room temperature

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Journal of Advanced Ceramics 2022年第4期11卷 603-614页

作者： yuchen zhu Hongyang ZHOU Rongxia HUANG Nianping YAN Xilin WANG Guanghua LIU Zhidong JIA Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China State Grade Jiangxi Electric Power Research Institute Nanchang 330000China State Key Laboratory of New Ceramics and Fine Processing Tsinghua University School of Materials Science and TechnologyTsinghua UniversityBeijing 100084China

This is the first study to conduct the flash sintering of 3 mol%yttria-stabilized zirconia(3YSZ)ceramics at room temperature(25℃)under a strong electric field,larger than 1 kV/*** the standard atmospheric pressure(101 kPa),the probability of successful sintering is approximately half of that at low atmospheric pressure,lower than 80 *** success of the proposed flash sintering process was determined based on the high electric arc performance at different atmospheric pressures ranging from 20 to 100 *** 3YSZ samples achieved a maximum relative density of 99.5%with a grain size of~200 *** results showed that as the atmospheric pressure decreases,the onset electric field of flash sintering decreases,corresponding to the empirical formula of the flashover ***,flash sintering was found to be triggered by the surface flashover of ceramic samples,and the electric arc on the sample surfaces floated upward before complete flash sintering at overly high pressures,resulting in the failure of flash *** study reveals a new method for the facile preparation of flash-sintered ceramics at room temperature,which will promote the application of flash sintering in the ceramic industry.

关键词： flash sintering yttria-stabilized zirconia(YSZ) room temperature flashover AC field low atmospheric pressure

Two-Stage Scheme for Disturbance Rejection Hovering Control of Underwater Vehicles

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Journal of Shanghai Jiaotong university(Science) 2022年第3期27卷 375-382页

作者： BI Anyuan FENG Zhengping zhu yuchen DENG Xu School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China b.State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China

A two-stage model-independent hovering control scheme for underwater vehicles,which are subject to unknown yet constant external disturbance,to eliminate steady-state depth error is ***derivative(PD)state feedback control law is adopted as the ballast mass planner at the first stage for the vehicle to reach both hydrostatic balance and a steady *** residual depth error is then removed by an additional disturbance rejection control at the second *** asymptotic stability of the whole system is guaranteed via Lyapunov *** effectiveness of the proposed scheme is illustrated by the simulation of diving control of an underwater vehicle with hydraulic variable ballast system.

关键词： underwater vehicles hovering control disturbance rejection variable ballast systems Lyapunov stability

Review of flash sintering with strong electric field

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High Voltage 2022年第1期7卷 1-11页

作者： Hongyang Zhou Xiang Li yuchen zhu Jieming Liu Angxuan Wu Guoming Ma Xilin Wang Zhidong Jia Liming Wang Guangdong Engineering Technology Research Centre of Power Equipment Reliability in Complicated Coastal Environments Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenGuangdongChina School of Electrical and Electronic Engineering North China Electric Power UniversityBeijingChina

Flash sintering is a novel field‐assisted sintering technology for ceramics that allows a dramatic reduction in processing time and *** 2010,when flash sintering was first reported,it has been a focus of research interest in the field of materials *** study results have confirmed that the sintering temperature decreases with the strength of the applied electric field;for some ceramics,the sintering temperature can be lowered even to room *** represents an innovative breakthrough for ceramic sintering at ultra‐low ***,once the electric field strength in flash sintering is increased,new questions and challenges arise,such as whether or not partial discharge occurs in the green body if under electro‐thermal coupling stress,how to quantitatively analyse the impact of discharge on sintering,and,moreover,whether the sintering mechanism under a strong electric field is consistent with that under a weak electric *** research questions require knowledge of partial discharge detection,dielectric theory,and other topics that are beyond the scope of materials *** address this need,this review summarises the work carried out in flash sintering with a strong electric field from the perspective of high voltage and insulation ***,the flash sintering process and mechanism are briefly ***,the published literature on flash sintering with a strong electric field for various ceramic materials is summarised in *** addition,experimental phenomena that are observed in flash sintering with a strong electric field,such as flash and blackening,are ***,some suggestions for future work are *** is anticipated that the knowledge gap between different areas of study can be filled by this review.

关键词： flash knowledge field

Characteristic changes in astrocyte properties during astrocyte-to-neuron conversion induced by NeuroD1/Ascl1/Dlx2

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Neural Regeneration Research 2025年第6期20卷 1801-1815页

作者： Qing He Zhen Wang yuchen Wang Mengjie zhu Zhile Liang Kanghong Zhang Yuge Xu Gong Chen GHM Institute of CNS Regeneration Jinan UniversityGuangzhouGuangdong ProvinceChina

Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.

关键词： aquaporin-4 Ascl1 astrocyte cortex Dlx2 gap junction glia-to-neuron conversion neural regeneration NeuroD1 reprogramming

债权人撤销权程序的诉判关系与审执关系——兼评最高人民法院118号指导案例

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法学 2023年第8期 117-132页

作者：朱禹臣北京大学法学院

债权人撤销权程序在诉判关系和审执关系上存在错配。最高人民法院118号指导案例中的债权人仅诉请撤销,但法院却在此基础上判决返还股权,有违处分原则。鉴于给付效果存在多种解释,宜将其在诉讼中作为主要争点处理。返还关系属于独立的诉... 详细信息

债权人撤销权程序在诉判关系和审执关系上存在错配。最高人民法院118号指导案例中的债权人仅诉请撤销,但法院却在此基础上判决返还股权,有违处分原则。鉴于给付效果存在多种解释,宜将其在诉讼中作为主要争点处理。返还关系属于独立的诉讼标的,法院应在释明的前提下对两诉合并审理,如此也有利于债权人明示关于给付效果的具体诉求。以该案为代表的裁判规则认为撤销后返还的给付判决具备执行力,此种理解混淆了主债权抑或撤销权作为执行的权利基础。基于保全债务人责任财产的目的,撤销权判决无需被执行。责任说下的相对人向债权人承担一般担保责任、落实给付关系须以主债权可执行为前提。物权说下的债权人本非受领主体,要求相对人向其履行的主张亦可被解释为关于主债权的诉请,若主债权无法执行则难以介入。如该案原告同时提起主债权给付诉讼,为维护其他竞争债权人的受偿可能,宜将撤销权判决认定为主债权执行过程中确认责任财产所在的线索,该判决原则上不能作为执行依据。

关键词：债权人撤销权债权保全处分原则申请执行权执行依据

告别晚明:清初京城文人的文化转型与思想变革

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北京师范大学学报（社会科学版） 2023年第5期 74-84页

作者：诸雨辰北京师范大学文学院北京100875

从遗民的视角透视明清之际的思想文化转型,呈现出的往往是停滞、消歇或终结的消极一面。而关注那些进入政治与文化中心的京城文人群体,则能看到易代之际思想文化带有延续性、创造性的特点。清初京城文人是重要却易被忽视的文人群体,他... 详细信息

从遗民的视角透视明清之际的思想文化转型,呈现出的往往是停滞、消歇或终结的消极一面。而关注那些进入政治与文化中心的京城文人群体,则能看到易代之际思想文化带有延续性、创造性的特点。清初京城文人是重要却易被忽视的文人群体,他们有着以苦为荣、以雅为高、以群为乐的价值追求,其文化思想转型呈现出既变异又承续的复杂理路。这些身居京城的文人因自感失节而萌生愧悔意识,又因易代而形成惶惑情感,由此产生了从压抑严苛到温柔敦厚的士风转型,以及由抽象思辨到传承文明的价值转向,整体上呈现出与晚明思潮相异的特色。他们在历史叙述、经典解读以及审美评鉴中深化了对主体意志与自由选择的思考,又接续了晚明思潮对自我意识的探寻,从另一角度体现出中华文明的韧性。

关键词：清初京城文人心态文化转型思想变革