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Aero-structural design of joined-wing aircraft based on high-fidelity model

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Chinese Journal of Aeronautics 2024年第4期37卷 363-377页

作者： Cheng HE Fengjiang zhan Luchuang ma Gang CHEN Jianying ma Unmanned Air Vehicle Research Institute Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Advanced Technology for Small and Medium-sized UAV Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Aerospace System Engineering Shanghai Shanghai 201108China

The joined-wing configuration reduces induced drag and structural weight by connecting the rear wing to the front *** addition,the rear wing can replace the role of the horizontal tail of a conventional aircraft,thus eliminating the aerodynamic drag and weight associated with the horizontal *** particular shape creates a highly coupled relationship between aerodynamics and structure,which must be fully considered during the overall design process to enhance aircraft *** this research,an aero-structural design model of the joined-wing aircraft is constructed based on high-fidelity computational fluid dynamics and structural finite element *** model is able to obtain accurate aerodynamic loads for the non-planar wing and to simulate the statically indeterminate structure of the closed wing *** influence of the joined-wing shape parameters on the aerodynamic and structural disciplines,as well as the influence of geometric nonlinear characteristics,deformation constraints and buckling constraints on the structural weight are all taken into *** model is applied to complete the aero-structural design optimization of a high-altitude long-endurance joined-wing aircraft,and wind tunnel tests are *** test results verify the credibility of the design model proposed and the validity of the design environment.

关键词： Joined-wing configuration Aircraft design Aero-structural design Finite element Wind tunnel test

Enhanced memristor performance via coupling effect of oxygen vacancy and ferroelectric polarization

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Journal of materials Science & Technology 2024年第4期171卷 139-146页

作者： Zhi yun Yue Zhi Dong zhang zhan Jie Wang Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

As a new type of nonvolatile memory,the resistive memristor has broad application prospects in in-formation storage and neural computing based on its excellent resistive switching(RS)*** present,it is still a great challenge to improve both ferroelectric polarization and leakage current to achieve a high RS on/offratio of ferroelectric ***,epitaxial Pb(Zr_(0.40)Ti_(0.60))O_(3)(PZT)thin films with low content Ca doping were deposited on the Nb:SrTiO_(3)substrate to prepare PCZT/NSTO het-erostructures and their RS behaviors were *** research findings show that compared with pure PZT film,the ferroelectric polarization of 1-mol%-Ca-doped PZT film is slightly improved,while the leak-age current is increased by three orders of ***,the RS on/offratio reaches 2.5×10^(5),about three orders of magnitude higher than pure PZT *** theoretical analysis reveals that the RS behavior of PCZT/NSTO heterostructures is controlled by the PCZT/NSTO interfacial barrier and the space charge-limited current *** results demonstrate that the ferroelectricity and electricity of ferroelectric thin films can be improved simultaneously by doping low-content Ca ions to increase the RS performance,which provides a good reference for the development of high-performance ferroelectric memristor devices.

关键词： Ferroelectric memristor Ca-doped PZT Ferroelectric polarization Oxygen vacancies Resistive switching

Land-population-industry based village evolution and its influencing factors in the upper Tuojiang River

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Journal of Mountain Science 2024年第8期21卷 2790-2809页

作者： zhan yunjun JI Yuxin HUANG Jiejun ma Changying ma Chuanqi School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China

With economic development and urbanization in China,the rural settlements have experienced great *** explore the evolution process of rural settlements in terms of land,population and industry can reveal the development law of rural spatial distribution,population structure and industrial economy in different stages and *** the development status and evolution characteristics of villages in the upper Tuojiang River basin in Southwest China in the past 20 years are of significant *** upper Tuojiang River basin includes the main types of terrain found in the Southwest region:mountainous,plains,and hills,exhibiting a certain typicality of geographical *** study took towns and townships at the town-level scale as the basic unit of research,and constructed an evaluation system for village evolution based on'land,population,and industry'.It employed Criteria Importance Through Inter-Criteria Correlation(CRITIC)analysis to examine the characteristics of village evolution in the area from 2000 to 2020,and used geographic detector analysis to identify the leading factors affecting village *** results show that:(1)From 2000 to 2010,villages in the upper Tuojiang River basin experienced significant changes,and the pace of these transformations slowed from 2010 to 2020.(2)From a comprehensive perspective,from 2000 to 2020,villages in hilly areas show a decline,while villages in plain areas near the city center show a positive urbanization development.(3)Road accessibility and distance from the city center are the main factors that explain the spatial differentiation of village evolution degree in the study *** study elucidates the spatiotemporal evolution characteristics of villages in the upper Tuojiang River basin and identifies the primary factors contributing to their changes,which will provide a reference for investigating the development of rural areas in different terrains of Southwest China.

关键词： Village evolution Land Population Industry Geographic detector

A Self-sensing TSA-actuated Anthropomorphic Robot Hand

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Journal of Bionic Engineering 2024年第3期21卷 1174-1190页

作者： Chanchan Xu Shuai Dong Yifan ma Jingwei zhan Yucheng Wang Xiaojie Wang Institute of Intelligent machines Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei230031China CAS Key Laboratory of Mechanical Behavior and Design of materials Department of Precision Machinery and Precision InstrumentationUniversity of Science and Technology of ChinaHefei230026China Institutes of Physical Science and Information Technology Anhui UniversityHefei230601China

This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output forces,high efficiency,compactness,inherent compliance,and the ability to transmit power over ***,conventional sensors used in TSA-actuated robotic hands increase stiffness,mass,volume,and complexity,making feedback control *** address this issue,a novel self-sensing approach is proposed using strain-sensing string based on Conductive Polymer Composite(CPC).By measuring the resistance changes in the strain-sensing string,the bending angle of the robot hand's fingers can be estimated,enabling closed-loop control without external *** developed self-sensing anthropomorphic robot hand comprises a 3D-printed structure with five fingers,a palm,five self-sensing TSAs,and a 3D-printed *** studies validate the self-sensing properties of the TSA and the anthropomorphic robot ***,a real-time Virtual Reality(VR)monitoring system is implemented for visualizing and monitoring the robot hand's movements using its self-sensing *** research contributes valuable insights and advancements to the field of intelligent prosthetics and robotic end grippers.

关键词： Anthropomorphic robot hand Twisted string actuator Self-sensing Conductive polymer composite Virtual reality monitoring

Dimensional reduction enhances photocatalytic carbon dioxide reduction performance of metal-organic frameworks

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Nano Research 2024年第5期17卷 3653-3659页

作者： Kaiyue ma Jixin Li Jinlu Liu Chunguang Li zhan Shi Shouhua Feng State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China

Metal-organic frameworks(MOFs)have shown significant potential as *** has been widely assumed that all catalytic active sites within MOFs are functional in photocatalytic reactions but for a three-dimensional MOF,whether the internal catalytic active sites can effectively absorb light and actively contribute to photocatalytic reactions remains to be *** this context,we synthesized a two-dimensional nanosheet MOF(2D-MOF)and a three-dimensional bulk MOF(3D-MOF)composed of Zr^(6) clusters and tetracarboxylic porphyrin(TCPP)by the approach described in the ***(bpy)(CO)^(3)Cl(bpy=2,2’-bipyridine),which has remarkable CO_(2) photoreduction ability,was introduced to the two MOFs to create two new photocatalysts 2D-MOF-Re and 3D-MOF-Re,*** CO_(2) reduction experiments show that based on the equal number of catalytic active sites,the CO turnover number(TON)of 2D-MOF-Re reaches 27.8 in 6 h,which is 50 times that of *** result shows that certain catalytic active sites inside the bulk MOF are inactive due to the inability to absorb *** study illuminates the potential of the dimensional reduction approach in the design of photocatalysts to exploit the capabilities fully.

关键词： photocatalysis CO_(2)reduction metal-organic frameworks(MOFs) nanosheets light absorption

Cucurbit[n]uril-based nanostructure construction and modification

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Chinese Chemical Letters 2024年第8期35卷 138-148页

作者： Lijun mao Shuo Li Xin zhang zhan-Ting Li Da ma School of Pharmaceutical Engineering&Institute for Advanced Studies Taizhou UniversityJiaojiang 318000China Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China

New fabrication method of nanostructures is of great importance for the applications of nanoscience and *** review summarizes cucurbit[n]uril(CB[n])-based nanostructure fabrication and modification *** strategies include the use of CB[n]s as building blocks and supramolecular crosslinkers to fabricate nanostructures,to surface modify nanostructures,and as gatekeepers to control the release of encapsulated *** nanostructures are used for drug delivery,bioimaging,chemical sensing,catalysis and other ***[n]s often play a vital role in the fabrication of these nanos-tructures,and the realization of the applications.

关键词： Cucurbit[n]uril Nanostructure Host-guest interaction Nanofabrication

Effects of the Resident Basic Medical Insurance Reform on Household Consumption in China

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China & World Economy 2024年第1期32卷 96-129页

作者： Shuheng Yu Xinxin ma Peng zhan School of Public Affairs Institute for Common Prosperity and DevelopmentZhejiang UniversityChina Faculty of Economics Hosei UniversityJapan

This paper investigates the causal relationship between the Urban and Rural Resident Basic Medical Insurance(URRBMI)reform and household consumption in urban China using data from the Chinese Household Income Project survey and employing combination of the propensity score matching and difference-in-differences *** results yield three ***,the reform affected both the amount and share of household ***,the reform led to an increase in total household consumption,encompassing both medical and nonmedical *** these,the proportion of medical consumption increased,while the proportion of nonmedical consumption ***,the impact of the URRBMI reform varied across consumption categories within nonmedical ***,consumption for education and entertainment industries are positively impacted by the URRBMI reform in terms of both quantity and ***,low-income households benefit more from the URRBMI reform compared to middle-and high-income *** main channels through which the URRBMI reform affects household consumption were the price effect and the crowding out effect on precautionary savings.

关键词： household consumption nonmedical consumption out-of-pocket expenses reimbursement ratio

SDCC: software-defined collective communication for distributed training

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Science China(Information Sciences) 2024年第9期67卷 105-125页

作者： Xin JIN Zhen zhanG yunshan JIA yun ma Xuanzhe LIU School of Computer Science Peking University Department of Computer Science and Technology Johns Hopkins University

Communication is crucial to the performance of distributed training. Today's solutions tightly couple the control and data planes and lack flexibility, generality, and performance. In this study, we present SDCC, a software-defined collective communication framework for distributed training. SDCC is based on the principle of modern systems design to effectively decouple the control plane from the data *** abstracts the operations for collective communication in distributed training with dataflow operations and unifies computing and communication with a single dataflow graph. The abstraction, together with the unification, is powerful: it enables users to easily express new and existing collective communication algorithms and optimizations, simplifies the integration with different computing engines(e.g., Py Torch and Tensor Flow) and network transports(e.g., Linux TCP and kernel bypass), and allows the system to improve performance by exploiting parallelism exposed by the dataflow graph. We further demonstrate the benefits of SDCC in four use cases.

关键词： machine learning systems distributed training deep learning collective communication software-defined networking

Comprehensive tensile properties improved by deep cryogenic treatment prior to aging in friction-stir-welded 2198 Al–Li alloy

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Rare Metals 2024年第10期43卷 5403-5409页

作者： Jian-Qiu Sun Yue ma Chong Gao Hong-yun Luo School of materials Science and Engineering Beihang University Chinalco Research Institute of Science and Technology

In order to improve the comprehensive mechanical properties,deep cryogenic treatment （DCT）prior to aging was carried out on friction-stir-welded（FSW） 2198 Al-Li alloy;afterward,the microstructure and tensile properties were characterized by means of optical microscopy （OM）,transmission electron microscopy（TEM） and tensile *** results show that FSW 2198 alloy through DCT prior to aging （DAT） possesses superior tensile properties than conventional aging treatment （AT）The microstructural analysis reveals that DAT alloy exhibits a finer grain structure,since DCT might effectively alleviate the residual stress in FSW 2198 alloy and thus decrease the driving force for grain coarsening in subsequent aging ***,DCT generates dislocation multiplication,which provides more preferential nucleation sites for T1 （Al2CuLi） phase during subsequent aging treatment,resulting in high-density fine T1 phases and thin precipitate-free zone within DAT *** reasonable microstructure leads to DAT alloy possessing better strength-ductility combination compared to AT alloy.

关键词： Al–Li alloy Deep cryogenic treatment Friction stir welding Tensile properties