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非合作线谱声源分布式定位方法

应用声学 2024年第3期43卷 654-660页

作者：邹男于金正桑志远李娜苏薪元杨嘉轩惠云梦哈尔滨工程大学水声技术全国重点实验室哈尔滨150001 海洋信息获取与安全工信部重点实验室(哈尔滨工程大学)工业和信息化部哈尔滨150001 哈尔滨工程大学水声工程学院哈尔滨150001

非合作目标定位是水声定位领域的研究热点。为充分挖掘并利用各类可观测参数,提高非合作目标定位能力,提出一种基于目标频率变化信息的非合作目标定位方法。该方法针对匀速直线运动目标的定位问题,首先根据多普勒频移原理,建立观测频率... 详细信息

非合作目标定位是水声定位领域的研究热点。为充分挖掘并利用各类可观测参数,提高非合作目标定位能力,提出一种基于目标频率变化信息的非合作目标定位方法。该方法针对匀速直线运动目标的定位问题,首先根据多普勒频移原理,建立观测频率与目标辐射频率、目标运动速度、位置之间的函数映射关系,利用最小均方准则建立目标函数,通过优化算法估计分布式定位系统中各个测量单元与目标运动轨迹的致近点距离,最后综合各观测节点的测距结果,构建几何定位模型,求得目标运动轨迹的解析解。通过仿真分析,证明了该方法的有效性,并指出了该方法需要目标通过与各测量单元的致近点才能获得较好的距离估计能力。文中分析了不同频率估计精度对定位精度的影响,结果表明,提出的定位方法对测频精度具有一定的容限,是一种高精度的非合作线谱声源定位方法。

关键词：非合作定位被动定位信赖域优化方法被动测距目标运动分析

Dual-modification of manganese oxide by heterostructure and cation pre-intercalation for high-rate and stable zinc-ion storage

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Journal of Energy Chemistry 2022年第4期31卷 82-91页

作者： Song Wang Weibing Ma zhiyuan sang Feng Hou Wenping Si Jingdong Guo Ji Liang De'an Yang Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300072China

Zinc-ion batteries(ZIBs)possess great advantages in terms of high safety and low cost,and are regarded as promising alternatives to lithium-ion batteries(LIBs).However,limited by the electrochemical kinetics and structural stability of the typical cathode materials,it is still difficult to simultaneously achieve high rates and high cycling stability for ***,we present a manganese oxide(Sn_(x)Mn O_(2)/Sn O_(2))material that is dual-modified by Sn O_(2)/Mn O_(2)heterostructures and pre-intercalated Sn;cations as the cathode material for *** modification provides sufficient hetero-interfaces and expanded interlayer spacing in the material,which greatly facilitates the insertion/extraction of Zn^(2+).Meanwhile,the“structural pillars”of Sn^(4+) cations and the“pinning effect”of SnO_(2)also structurally stabilizes the Mn O_(2)species during the repeated Zn^(2+) insertion/extraction,leading to ultra-high cycling *** to these merits,the Sn_(x)MnO_(2)/SnO_(2)cathode exhibits a high reversible capacity of 316.1 m Ah g^(-1) at 0.3 A g^(-1),superior rate capability of 179.4 m Ah g^(-1) at 2 A g^(-1),and 92.4%capacity retention after 2000 ***,this work would provide a promising yet efficient strategy by combining heterostructures and cations preintercalation to obtain high-performance cathodes for ZIBs.

关键词： Zinc-ion battery Manganese-based cathode material Pre-intercalation Heterostructure

High-capacity,high-rate,and dendrite-free lithium metal anodes based on a 3D mixed electronic-ionic conductive and lithiophilic scaffold

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Science China Materials 2022年第11期65卷 2989-2996页

作者： Tao Zhang zhiyuan sang Lichang Yin Yonghuan Han Wenping Si Yuxin Yin Feng Hou Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300354China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Tianjin Lishen Battery Joint Stock Ltd Co Tianjin 300384China

Lithium metal anode possesses a high theoretical capacity and the lowest redox potential,while the severe growth of Li dendrite prevents its practical ***,we prepared a structure of Li_(3)P nanosheets and Ni nanoparticles decorated on Ni foam(NF)as a three-dimensional(3 D)scaffold for dendrite-free Li metal anodes(Li-Li_(3)P/Ni@Ni foam anodes,shortened as L-LPNNF)using a facile melting *** LiP nanosheets exhibit excellent Li-ion conductivity as well as superior lithiophilicity,and the 3 D nickel scaffold provides sufficient electron conductivity and ensures structure ***,symmetric cells assembled by L-LPNNF possess lowered voltage hysteresis and improved long cycle stability(a voltage hysteresis of 104.2 mV after 500 cycles at a high current density of 20 mA cm^(-2) with a high capacity of 10 mA h cm^(-2)),compared with the cells assembled with Li foil or Li-NF ***,the full cells with paired L-LPNNF anodes and commercial LiFePOcathodes suggest a specific capacity of 124.6 mA h gand capacity retention of 90.8%after 180 cycles with the Coulombic efficiency(CE)of~100%at a current rate of 1 *** work provides a potentially scalable option for preparing a mixed electronic-ionic conductive and lithiophilic scaffold for dendrite-free Li anodes at high current densities.

关键词： lithium metal anodes dendrite-free mixed ionic/electronic conductivity 3D lithiophilic scaffold

Point defects in 2-D liquid crystals with a singular potential:Profiles and stability

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Science China Mathematics 2024年第11期67卷 2515-2540页

作者： zhiyuan Geng Wei Wang Basque Center for Applied Mathematics School of Mathematical Sciences Zhejiang University

We study radial symmetric point defects with degree k/2 in the 2-D disk or R2in the Q-tensor framework with a singular bulk energy,which is defined by Bingham ***,we obtain the existence of solutions for the profiles of radial symmetric point defects with degree k/2 in the 2-D disk or ***,we prove that the solution is stable for |k| = 1 and unstable for |k| > *** identities are derived and utilized throughout the proof of existence and stability/instability.

关键词： radial symmetric point defects singular bulk potential Bingham closure stability

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Summer extreme precipitation patterns and synoptic-scale circulation precursors over the Tibetan Plateau

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Science China Earth Sciences 2024年第5期67卷 1625-1638页

作者： zhiyuan DING Yao HA Zhong ZHONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing 210023China Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing 210023China

In the context of global warming,the extreme summer precipitation over the Tibetan Plateau(TP)has changed *** this study,the summer(June–August)extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution(1/30°)precipitation dataset(TPHi Pr,1979–2020).The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were *** results showed that the summer extreme precipitation of the TP can be categorized into northwestern(NW),southeastern(SE),and southern Himalayan(HS)types based on extreme precipitation *** NW and SE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them,whereas the HS type is controlled by the localized subtropical anomalous *** the 8th day before the onset of the NW type,an anomalous cyclone was observed in the western Atlantic Ocean(60°W,50°N),which triggered the west-to-east quasi-latitudinal propagation of Rossby *** the onset day of the NW type,the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian Sea,the western part of Xinjiang,to the northeastern *** entered from the Arabian Sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern *** to the NW type,the precursors of the SE type appeared at higher latitudes and were more *** the 8th day before the onset of the SE type,an anomalous cyclone occurred near Greenland(60°W,70°N)and excited Rossby waves propagating *** the onset day of the SE type,the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast directi

关键词： Tibetan Plateau Summer extreme precipitation Atmospheric circulation anomaly Precursor Teleconnection wave train

Global practical stabilization of the double integrator system with an imperfect sensor and subject to a bounded disturbance

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Control Theory and Technology 2024年第3期22卷 468-478页

作者： zhiyuan Zhu Yuanlong Li Zongli Lin Department of Automation Shanghai Jiao Tong Universityand Key Laboratory of System Control and Information Processing of Ministry of EducationShanghai 200240China Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaP.0.Box 400743CharlottesvilleVA 22904-4743USA

This paper is concerned with global practical stabilization of the double integrator system with an imperfect sensor and subject to an additive bounded output *** imperfect sensor nonlinearity possesses the nonlinear characteristics of saturation and dead *** of the presence of output dead zone and the additive disturbance,the states cannot be expected to driven into an arbitrarily small neighborhood of the *** solve the global practical stabilization problem,we proposes a low gain-based linear dynamic output feedback law,under which the first state enters and remains in a bounded set whose size is depended on the bound of disturbance and the range of dead zone and the second state enters and remains in a pre-specified arbitrarily small set,both in finite *** results illustrate the effectiveness of our proposed control method.

关键词： Output saturation Disturbance rejection Output dead zone Low gain feedback-Linear output feedback Practical stabilization

Price Masking Strategy of Cross-Border E-Commerce Platform Financing

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Journal of Systems Science & Complexity 2024年第2期37卷 668-691页

作者： LI Jianbin HANG Zhouxin CHEN zhiyuan XIAO Shan School of Management Huazhong University of Science and TechnologyWuhan 430074China School of Economics and Management Wuhan UniversityWuhan 430072China

E-commerce platform financing is a new service pattern of supply chain ***,this pattern may bring some new issues when considering the problem of cash flow shortage and financing difficulties of small and medium-sized *** enterprises use this service,they worry about the leakage of preferential wholesale price when applying the full loan amount and providing the true transaction *** on the model consisting of a supplier,a retailer and a cross-border e-commerce platform,the authors design a price masking strategy to prevent the retailer’s preferential wholesale price information from *** authors analyze the profit of the retailer and the platform before and after adopting the price masking *** authors find that the price masking strategy always benefits the ***,the optimal profit of the retailer and the platform are both affected by the loan interest ***,there exists a range of loan interest rates that can benefit both the retailer and the platform if the price masking strategy is *** research emphasizes that platform can expand the total business volume by allowing retailers to use price masking *** other words,there will be more and more retailers attracted by the strategy,which benefits the long-term growth of cross-border e-commerce platform financing.

关键词： Cross-border e-commerce e-commerce platform financing price masking supply chain finance

Simulation of nanofluid natural convection based on single-particle hydrodynamics in energy-conserving dissipative particle dynamics(eDPD)

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1429-1446页

作者： Wei LU Shuo CHEN zhiyuan YU Jiayi ZHAO School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China Shanghai Key Laboratory of Vehicle Aerodynamics and Vehicle Thermal Management Systems Tongji UniversityShanghai 201804China School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China

In the present study,the nanofliud natural convection is investigated by the energy-conserving dissipative particle dynamics(eDPD)method,where the nanoparticles are considered at the single-particle *** thermal expansion coefficientβand the viscosityμof the simulated system containing nanoparticles are calculated and found to be in close alignment with the previous simulation *** single-particle hydrodynamics in e DPD enables simulations of nanofluid natural convection with higher Rayleigh numbers and greater nanoparticle volume ***,this approach is utilized to simulate the nanoparticle distribution during the enhanced heat transfer process in the nanofluid natural *** localized aggregation of nanoparticles enhances the heat transfer performance of the nanofluid under specific Rayleigh numbers and nanoparticles volume fractions.

关键词： single-particle hydrodynamics energy-conserving dissipative particle dynamics(eDPD) nanoparticle nanofluid heat transfer

Hepatitis B virus infection, infertility, and assisted reproduction

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第8期25卷 672-685页

作者： Lingjian ZHANG Fangfang ZHANG zhiyuan MA Jie JIN Department of Infectious Diseases Affiliated Hangzhou First People’s HospitalSchool of MedicineZhejiang UniversityHangzhou 310003China Women’s Hospital School of MedicineZhejiang UniversityHangzhou 310003China Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province Affiliated Hangzhou First People’s HospitalZhejiang University School of MedicineHangzhou 310003China

Background:Hepatitis B virus(HBV)is one of the most widespread viruses worldwide and a major cause of hepatitis,cirrhosis,and hepatocellular *** studies have revealed the impacts of HBV infection on *** increasing number of infertile couples with chronic hepatitis B(CHB)virus infection choose assisted reproductive technology(ART)to meet their fertility *** the high prevalence of HBV,the effects of HBV infection on assisted reproduction treatment remain limited and ***:The aim of this study was to provide a comprehensive overview of the effect of HBV infection on fertility and discuss its effects on pregnancy outcomes,vertical transmission,pregnancy complications,and viral activity during ART ***:We conducted a literature search in PubMed for studies on HBV infection and ART published from 1996 to ***:HBV infection negatively affected fertility in both males and *** research shows that HBV infection may increase the risk of pregnancy complications in couples undergoing assisted reproduction *** impact of HBV infection on the pregnancy outcomes of ART is still *** evidence does not support that ART increases the risk of vertical transmission of HBV,while relevant studies are *** the development of ART,the risk of HBV reactivation(HBVr)is increasing,especially due to the wide application of immunosuppressive ***:Regular HBV infection screening and HBVr risk stratification and management are essential to prevent HBVr during *** determination of optimal strategy and timing of prophylactic anti-HBV therapy during ART still needs further investigation.

关键词： Assisted reproductive technology(ART) Hepatitis B virus(HBV) Immunosuppressive agent Pregnancy