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Spin manipulations through electrical and thermoelectrical transport in magnetic tunnel junctions

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Science China(Physics,Mechanics & Astronomy) 2013年第1期56卷 166-183页

作者： zhu ZhenGang su Gang School of Electronics Eletrical and Communication EngineeringUniversity of Chinese Academy of Sciences Institut fr Physik Martin-Luther-UniversittHalle-Wittenberg Nanotechnikum-WeinbergHeinrich-Damerow-Strasse 4 D-06120 Halle(Saale)Germany School of Physics University of Chinese Academy of Sciences

A brief review is presented,which includes the direct current,alternate current,electrical and thermoelectrical transport as well as spin transfer effect in a variety of spin-based nanostructures such as the magnetic tunnel junction(MTJ),ferromagnet(FM)-quantum dot(QD)/FM-FM,double barrier MTJ,FM-marginal Fermi liquid-FM,FM-unconventional superconductor-FM(FUSF),quantum ring and optical spin-field-effect *** magnetoresistances in those structures,spin accumulation effect in FM-QD-FM and FUSF systems,spin injection and spin filter into semiconductor,spin transfer effect,photon-assisted spin transport,magnonassisted tunneling,electron-electron interaction effect on spin transport,laser-controlled spin dynamics,and thermoelectrical spin transport are discussed.

关键词： spintronics magnetic tunnel junction spin transport magnetoresistance spin transfer torque spin injection spin filter spin-valve spin-orbit

On the Global Convergence of a Projective Trust Region Algorithm for Nonlinear Equality Constrained Optimization

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Acta Mathematica Sinica,English Series 2018年第12期34卷 1804-1828页

作者： Yong Gang pei De Tong zhu Mathematics and Information Science He 'nan Normal University Xinxiang 453007 P. R. China Mathematics and Science College Shanghai Normal University Shanghai 200234 P. R. China

A trust-region sequential quadratic programming （SQP） method is developed and analyzed for the solution of smooth equality constrained optimization problems. The trust-region SQP algorithm is based on filter line search technique and a composite-step approach, which decomposes the overall step as sum of a vertical step and a horizontal step. The algorithm includes critical modifications of horizontal step computation. One orthogonal projective matrix of the Jacobian of constraint functions is employed in trust-region subproblems. The orthogonal projection gives the null space of the trans- position of the Jacobian of the constraint function. Theoretical analysis shows that the new algorithm retains the global convergence to the first-order critical points under rather general conditions. The preliminary numerical results are reported.

关键词： Sequential quadratic programming trust-region filter line search projection global convergence

An improved practical model for wear prediction of revolute clearance joints in crank slider mechanisms

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Science China(Technological Sciences) 2013年第12期56卷 2953-2963页

作者： LI pei CHEN Wei zhu AiBin Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong University

A stationary clearance link algorithm(SCLA)for calculating the reaction-force of revolute clearance joints in crank slider mechanisms is proposed in this *** SCLA is more efficient than other algorithms of the same ***,based on the Winkler foundation model,an unsymmetrical Winkler foundation model and a double elastic layer Winkler model are *** integrating a dynamic model and the unsymmetrical Winkler foundation model with Archard wear model,an improved integrated wear prediction model is also generated.A series of experiments have been performed to compare with the predicted analysis data,and the results showed a good *** a real industry application,with the double elastic layer Winkler model,the integrated wear prediction model was successfully used to predict the wear depth of the joint bearing(bimetallic bearing)for the cantilever crane of a concrete pump truck of Sany Heavy Industry.

关键词： revolute clearance joint stationary clearance link algorithm unsymmetrical Winkler foundation model double elastic layer Winkler model

高校图书馆数字资源违规使用对策设计及其仿真校验

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现代情报 2025年第1期45卷 18-32页

作者：李英群裴雷朱静娴李亚菲彭星张晶南京大学信息管理学院江苏南京210023 南京大学数据智能与交叉创新实验室江苏南京210023 中国移动研究院北京100053

[目的/意义]高校图书馆数字资源违规使用治理政策涉及多方利益主体博弈,单一维度的分析视角无法从系统层面有效调和并解决这一矛盾冲突。[方法/过程]本文采用演化博弈理论框架,构建数据供应商、高校图书馆和用户的三方演化博弈模型,探... 详细信息

[目的/意义]高校图书馆数字资源违规使用治理政策涉及多方利益主体博弈,单一维度的分析视角无法从系统层面有效调和并解决这一矛盾冲突。[方法/过程]本文采用演化博弈理论框架,构建数据供应商、高校图书馆和用户的三方演化博弈模型,探究各主体的行为模式及其均衡稳定策略。通过构建层次结构模型对参数赋值,以提升仿真分析结果的可靠性和真实性。随后通过MATLAB仿真实验,剖析了各类因素对于演化博弈的影响机制与作用路径,厘清利益对象间的动态交互关系和关联结构。[结果/结论]研究结果显示,该博弈模型呈现出两种不同的演化稳定策略状态,并基于数据资源违规使用的现状,分别从三方博弈主体提出针对性的意见。

关键词：高校图书馆供应商用户数字资源合规使用违规使用政策设计演化博弈仿真分析

A Heat Transport Model Including the Effect of Non-Maxwellian Electron Distribution and Its Application in Laser Produced Plasma

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Chinese Physics Letters 1999年第7期16卷 520-522页

作者： zhu Shao-ping GU pei-jun Institute of Applied Physics and Computational Mathematics Beijing 100088

An electron heat transport model is given for studying laser-to-x-ray conversion of inertial confinement *** electron heat flux is derived based on a non-Maxwellian electron distribution,and the behavior of the heat flux is *** effect of the non-Maxwellian electron distribution on inverse bremsstrahlung heating rate and electron-ion heat transfer rate are also included in the present *** simulation results show that the effects of the non-Maxwellian electron distribution on laser absorption efficiency,laser-to-x-ray conversion efficiency and electron temperature in the coronal region are important.

关键词： Maxwell Electron distribution

Profiling the antibiotic resistome in soils between pristine and human-affected sites on the Tibetan Plateau

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Journal of Environmental Sciences 2022年第1期34卷 442-451页

作者： Hang Wang Xiaoxuan su Jianqiang su Yongguan zhu Kai Ding Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Yunnan Key Laboratory of Plateau Wetland Conservation Restoration and Ecological ServicesSouthwest Forestry UniversityKunming 650224China National Plateau Wetlands Research Center Southwest Forestry UniversityKunming 650224China

With increasing pressure from anthropogenic activity in pristine environments,the comprehensive profiling of antibiotic resistance genes(ARGs)is essential to evaluate the potential risks from human-induced antibiotic resistance in these under-studied ***,we characterized the microbial resistome in relatively pristine soil samples collected from four distinct habitats on the Tibetan Plateau,using a Smart chip based high-throughput q PCR *** compared these to soils from the same habitats that had been subjected to various anthropogenic activities,including residential sewage discharge,animal farming,atmospheric deposition,and tourism *** to pristine samples,an average of23.7%more ARGs were detected in the human-affected soils,and the ARGs enriched in these soils mainly encoded resistances to aminoglycoside and *** the four habitats studied,soils subjected to animal farming showed the highest risks of ARG enrichment and *** shown,the number of ARGs enriched(a total of 42),their fold changes(17.6 fold on average),and the co-occurrence complexity between ARGs and mobile genetic elements were all the highest in fecal-polluted *** well as antibiotics themselves,heavy metals also influenced ARG distributional patterns in Tibetan ***,compared to urban areas,the Tibetan Plateau had a low potential for ARG selection and exhibited low carriage of ARGs by mobile genetic elements,even in environments impacted by humans,suggesting that these ARGs have a limited capacity to *** present study examined the effects of multiple anthropogenic activities on the soil resistomes in relatively pristine environments.

关键词： Antibiotic resistance gene Resistome risk Tibetan plateau Animal farming Anthropogenic activity

NYFR output pulse radar signal TOA analysis using extended Fourier transform and its TOA estimation

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Journal of Systems Engineering and Electronics 2017年第2期28卷 212-223页

作者： Zhaoyang Qiu pei Wang Jun zhu Bin Tang School of Electronic Engineering University of Electronic Science and Technology of China Chengdu 611731 China

Nyquist folding receiver (NYFR) is a typical wideband analog-to-information architecture. Focusing on the non-cooperative receiving, the pulse radar signal intercepted by the NYFR in time domain is analyzed. The NYFR outputs under different input conditions are investigated based on the extended Fourier transform (EFT) and the sampling theorem. Combining with the characteristic of the NYFR output in time domain, a new time of arrival (TOA) estimation method based on the energy envelope and the wavelet transform is proposed. The proposed estimation method can be adapted for the non-cooperative situation. It has no requirement for prior information to determine the threshold and is not necessary to transform the signal into baseband. Simulation results prove the correctness of the NYFR output expressions and show the efficacy of the proposed estimation method. © 2017 Beijing Institute of Aerospace Information.

关键词： Fourier transforms Radar Time domain analysis Wavelet transforms

Flutter analysis of rotating beams with elastic restraints

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Applied Mathematics and Mechanics(English Edition) 2022年第5期43卷 761-776页

作者： Lüsen WANG zhu su Lifeng WANG State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The aeroelastic stability of rotating beams with elastic restraints is *** coupled bending-torsional Euler-Bernoulli beam and Timoshenko beam models are adopted for the structural *** Greenberg aerodynamic model is used to describe the unsteady aerodynamic *** additional centrifugal stiffness effect and elastic boundary conditions are considered in the form of potential energy.A modified Fourier series method is used to assume the displacement field function and solve the governing *** convergence and accuracy of the method are verified by comparison of numerical ***,the flutter analysis of the rotating beam structure is carried out,and the critical rotational velocity of the flutter is *** results show that the elastic boundary reduces the critical flutter velocity of the rotating beam,and the elastic range of torsional spring is larger than the elastic range of linear spring.

关键词： rotating beam modified Fourier series method elastic restraint flutter

Toward the third generation artificial intelligence

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Science China(Information Sciences) 2023年第2期66卷 5-23页

作者： Bo ZHANG Jun zhu Hang su Institute for Artificial Intelligence Tsinghua University

There have been two competing paradigms in artificial intelligence(AI) development ever since its birth in 1956, i.e., symbolism and connectionism(or sub-symbolism). While symbolism dominated AI research by the end of 1980s, connectionism gained momentum in the 1990s and is gradually displacing symbolism. This paper considers symbolism as the first generation of AI and connectionism as the second generation. However, each of these two paradigms simulates the human mind from only one *** cannot achieve true human behaviors by relying on only one paradigm. In order to develop novel AI technologies that are safe, reliable, and extensible, it is necessary to establish a new explainable and robust AI theory. To this end, this paper looks toward developing a third generation artificial intelligence by combining the current paradigms.

关键词： artificial intelligence symbolism connectionism dual-space model single-space model triple-space model