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Influence of the Nongyrotropy on the Gyrotropic Ring Instability

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Chinese Physics Letters 1998年第1期15卷 38-40页

作者： cao jin-bin WANG Xue-yi CAI Chun-lin Center for Space Science and Applied Research Chinese Academy of ScienceBeijing 100080

The instability driven by the nongyrotropic newborn ions is studied for oblique *** results show the influence of nongyrotropic on the gyrotropic ring instability decreases when the propagation angle *** growth rate in the case of nongyrotropic is smaller than that in the case of *** nongyrotropic also breaks the symmetry of the propagation of the waves in the plane perpendicular to the ambient magnetic field.

关键词： field symmetry ambient

Particle Simulations for Electron Beam-Plasma Interactions

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Chinese Physics Letters 1998年第12期15卷 895-897页

作者： ZHOU Guo-cheng LI Yang cao jin-bin WANG Xue-yi Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100080

The computer simulations of high-frequency instabilities excited by the high density electron beam and their nonlinear effect are ***-dimensional electromagnetic particle simulations are performed with different values of the electron beam-to-plasma density *** results show that for the high electron beam-to-background plasma density ratio,all the Langmuir waves and two electromagnetic waves with left-hand and right-hand circular polarizations(i.e.,the“L-O mode”and the“R-X mode”)propagating parallel to the magnetic field can be generated and the maximum values of wave electric fields are nearly the *** electron beam and background plasma are diffused and a part of energetic background electrons are obviously accelerated by the wave-particle *** heating of the beam and background plasma is mainly due to the electrostatic(Langmuir)wave-particle interactions,but the accelerations of a part of energetic background electrons may be mainly due to the electromagnetic wave-particle interactions.

关键词： beam Electron electrostatic

Nonadiabatic acceleration of plasma sheet ions related to ion cyclotron waves

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Science China(Technological Sciences) 2014年第12期57卷 2434-2440页

作者： WANG Zhi Qiang cao jin bin RME Henri DANDOURAS Iannis MA Yu Duan Department of Space Science and Application College of Astronautics Nanjing University of Aeronautics and Astronautics University of Toulouse UPS-OMP IRAP Toulouse 31082 France The French National Centre for Scientific Research The Research Institute in Astrophysics and Planetology Space Science Institute School of Astronautics Beihang University

The nonadiabatic acceleration of plasma sheet ions is important to the understanding of substorm energetic injections and the formation of ring current. Previous studies show that nonadiabatic acceleration of protons by magnetic field dipolarization is hard to occur at X>–10 RE because the time-scale of dipolarization(several minutes) is much larger than the gyroperiod of protons there(several seconds). In this paper, we present a case of nonadiabatic acceleration of plasma sheet ions observed by Cluster on October 30, 2006 at(XGSM, YGSM)=(-7.7, 4.7) RE. The nonadiabatic acceleration of ions is caused not by previously reported magnetospheric dipolarization but by the ultra low frequency(ULF) waves during magnetospheric dipolarization. The nonadiabatic acceleration of ions generates a new energy flux structure of ions, which is characterized by the usual energy flux increase of ions(28–80 ke V) and a concurrent energy flux decrease of ions in a lower energy range(10 e V–20 ke V). These new observations constitute a complete physical picture: The lower energy ions absorb the wave energy, and thus get accelerated to higher energy. We use a nonadiabatic model to interpret the ion energy flux variations. Both analytic and simulation results are in good agreement with the observations. This indicates that the nonadiabatic acceleration associated with ULF waves superposed on dipolarized magnetic field is an effective mechanism for ion energization in the near-Earth plasma sheet. The presented energy flux structures can be used as a proxy to identify the similar dynamic process.

关键词： nonadiabatic acceleration ion cyclotron waves wave-particle interaction

Dipole AlfvenVortex with Finite Ion Larmor Radius in a Low-Beta Plasma

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Chinese Physics Letters 2000年第7期17卷 517-518页

作者： WANG Xu-Yu HE Xian-Tu LIU Zhen-Xing cao jin-bin Institute of Applied Physics&Computational Mathematics Beijing 100088 Laboratory of Space Weather Center for Space Science&Applied ResearchChinese Academy of SciencesBeijing 100080

A set of nonlinear fluid equations which include the effects of ion gyroradius is derived to describe Alfven vortex. The correction of finite ion gyroradius to the Alfven vortex in the inertial region is much more significant than that in the kinetic region. The amplitude of the vortex is enhanced in both regions. The scale of the vortex in the kinetic region becomes larger whereas it becomes smaller in the inertial region.

关键词： vortex Radius radius

Difference Between the Ion Gyroviscous Effect and Hall Magnetohydrodynamic Effect in the Magnetic Reconnection

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Chinese Physics Letters 1999年第11期16卷 856-858页

作者： CAI Chun-lin ZHOU Guo-cheng cao jin-bin WANG De-ju Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100080

We study the ion gyroviscous effect and Hall magnetohydrodynamic (MHD) effect separately using the modified MHD simulation of the magnetopause. Simulations show that the ion gyroviscous effect is on the order of a characteristic scale of ion Larmor radius and is mainly limited near the magnetosheath boundary. The Hall MHD effect is on the order of a characteristic scale of ion inertial length and occurs mainly in the central region of the current layer. The magnetic field component out of the simulation plane has a bipolar structure near the magnetosheath boundary from the ion gyroviscous effect and a quadrupole structure in the central region of the current layer from the Hall MHD effect. These results are of fundamental importance in understanding the reconnection processes in space and astrophysical plasma.

关键词： viscous effect effect.

Modified Magnetohydrodynamic Model of Magnetic Reconnection

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Chinese Physics Letters 1999年第6期16卷 461-463页

作者： ZHOU Guo-cheng CAI Chun-lin cao jin-bin ZHANG Yang-ting CHEN Tao WANG De-ju Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100080

This paper presents the modified magnetohydrodynamic(MHD)model and simulations of solar wind-magnetosphere *** use the two-dimensional and three-component,compressible,resistive,ion gyroviscous and Hall MHD model,i.e.,including the ion Unite Larmor radius(FLR)and Hall MHD effects,but neglecting the electron inertia and electron FLR *** composed dynamic pressure pulses(shear variations in the How velocity)in the solar wind form gusts that continually buffet the magnetosphere and cause the time-dependent magnetic reconnection at the *** results show that the magnetic Held and the How velocity components perpendicular to the reconnection plane can be generated in magnetopause current *** vortical How structures can also occur in the magnetospheric side *** results are responsible for non-ideal MHD properties of the plasma fluid,i.e.,ion FLR and Hall MHD effects.

关键词： reconnection effects. inertia

Advanced Design of Soft Robots with Artificial Intelligence

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Nano-Micro Letters 2024年第10期16卷 474-521页

作者： Ying cao bingang Xu bin Li Hong Fu Nanotechnology Center School of Fashion and TextilesThe Hong Kong Polytechnic UniversityHong Kong 999077People's Republic of China Department of Mathematics and Information Technology The Education University of Hong KongHong Kong 999077People's Republic of China Bioinspired Engineering and Biomechanics Center Xi'an Jiaotong UniversityXi'an 710049People's Republic of China

In recent years,breakthrough has been made in the field of artificial intelligence(AI),which has also revolutionized the industry of *** robots featured with high-level safety,less weight,lower power consumption have always been one of the research ***,multifunctional sensors for perception of soft robotics have been rapidly developed,while more algorithms and models of machine learning with high accuracy have been optimized and *** of soft robots with AI have also been advanced ranging from multimodal sensing,human-machine interaction to effective actuation in robotic ***-less,comprehensive reviews concerning the new developments and strategies for the ingenious design of the soft robotic systems equipped with AI are ***,the new development is systematically reviewed in the field of soft robots with ***,background and mechanisms of soft robotic systems are briefed,after which development focused on how to endow the soft robots with AI,including the aspects of feeling,thought and reaction,is ***,applications of soft robots with AI are systematically summarized and discussed together with advanced strategies proposed for performance *** thoughts for future intelligent soft robotics are pointed ***,some perspectives are put forward.

关键词： Soft robotic systems Artificial intelligence Design tactics Review and perspective

Airflow Analytical Toolkit(AAT):A MATLAB-based analyzer for holistic studies on the dynamic characteristics of airflows

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Building Simulation 2024年第7期17卷 1137-1159页

作者： Zuoyu Xie Junhui Fan bin cao Yingxin Zhu Department of Building Science School of ArchitectureTsinghua UniversityBeijingChina Key Laboratory of Eco Planning&Green Building Ministry of Education(Tsinghua University)BeijingChina

The dynamic characteristics of different airflows on micro-scales have been explored from many perspectives since the late *** the one hand,most analytical tools and research subjects in previous contributions vary significantly:some only focus on fluctuant velocity features,while others pay attention to directional *** the other hand,despite the wide variety of existing analytical methods,they are not systematically classified and *** paper aims to establish a system including state-of-the-art tools for airflow analysis and to further design a holistic toolkit named Airflow Analytical Toolkit(AAT).The AAT contains two tools,responsible for analyzing the velocity and direction characteristics of airflows,each of which is integrated with multiple analytical *** assess the performance of the developed toolkit,we further take typical natural and mechanical winds as cases to show its excellent analytical *** the help of this toolkit,the great differences in velocity and directional characteristics among different airflows are *** comparative results reveal that not only is the velocity of natural wind more fluctuating than that of mechanical wind,but its incoming flow direction is also more *** AAT,serving as a powerful and user-friendly instrument,will hopefully offer great convenience in data analysis and guidance for a deeper understanding of the dynamic characteristics of airflows,and further remedy the gap in airflow analytical tools.

关键词： airflow analysis dynamic characteristic wind velocity wind direction thermal comfort wind comfort

A Robust Framework for Multimodal Sentiment Analysis with Noisy Labels Generated from Distributed Data Annotation

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2965-2984页

作者： Kai Jiang bin cao jing Fan School of Computer Science and Technology Zhejiang University of TechnologyHangzhou310023China

Multimodal sentiment analysis utilizes multimodal data such as text,facial expressions and voice to detect people’s *** the advent of distributed data collection and annotation,we can easily obtain and share such multimodal ***,due to professional discrepancies among annotators and lax quality control,noisy labels might be *** research suggests that deep neural networks(DNNs)will overfit noisy labels,leading to the poor performance of the *** address this challenging problem,we present a Multimodal Robust Meta Learning framework(MRML)for multimodal sentiment analysis to resist noisy labels and correlate distinct modalities ***,we propose a two-layer fusion net to deeply fuse different modalities and improve the quality of the multimodal data features for label correction and network ***,a multiple meta-learner(label corrector)strategy is proposed to enhance the label correction approach and prevent models from overfitting to noisy *** conducted experiments on three popular multimodal datasets to verify the superiority of ourmethod by comparing it with four baselines.

关键词： Distributed data collection multimodal sentiment analysis meta learning learn with noisy labels