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Progress on Solar Physics in China During 2004 - 2006

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空间科学学报 2006年第Z1期26卷 122-137页

作者： yan yihua ai guoxiang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

The solar physics studies in China during 2004-2006 from solar interior to solar atmospheres and solar-interplanetary space are summarized. These researches are arranged under the topics of solar interior, photosphere, chromosphere and transition region, corona, flares and CMEs (and the associated radio bursts, X-ray/γ-ray bursts and particle acceleration), solar wind, solar cycle, and ground-based instrumentation.

关键词： Solar physics

Progress on Space Solar Telescope in 2002-2004

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空间科学学报 2004年第Z1期24卷 60-63页

作者： ai guoxiang yan yihua JIN Shengzhen National Astronomical Observatories The Chinese Academy of Sciences Beijing 100012 China National Astronomical Observatories The Chinese Academy of Sciences Beijing 100012 China National Astronomical Observatories The Chinese Academy of Sciences Beijing 100012 China

The progress on Chinese Space Solar Telescope (SST) in 2002-2004 is introduced. The documentations on plans and outlines based on the standards of Chinese aerospace industry for SST mission has been fulfilled. The key technical problems of SST satellite platform and payloads are tackled during pre-study stage of the mission. The laboratory assembly and calibration of the main optical telescope of 1.2 m spherical mirror and 1 m plain mirror have been carried out with the accuracy of λ/40 and λ/30, respectively. The prototype at 17.1 nm for extreme ultraviolet telescope is under development and manufacture with a diameter of 13 cm. Its primary and secondary mirrors have a manufacturing error of 5nm with a roughness degree of less than 0.5 nm and a multiplayer reflection factor of better than 20%. The on-board scientific data processing unit has been developed. Prototypes for other payloads such as H and white light telescope, wide band spectroscopy in high energy and solar and interplanetary radio spectrometer have been developed accordingly.

关键词： Space telescope, Instrument, Astronoming, Solar physics

Progress on Space Solar Telescope in 2004 - 2006

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空间科学学报 2006年第Z1期26卷 14-16页

作者： ai guoxiang yan yihua yanG Shimo JIN Shengzhen National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

The progress on Chinese Space Solar Telescope (SST) in 2004-2006 is introduced. The scientific objectives are further clarified and the ground operation system has been planned. The 7 key technical problems of SST satellite platform and payloads have been tackled, which lay solid scientific and technological foundations for engineering prototype phase of the SST project. At present the SST project undergoes evaluation by CNSA and CAS so as to enter the engineering prototype phase of the SST project if it is finally approved.

关键词： Instrumentation, Space telescope, Solar physics

Adaptive estimation and control for uncertain nonlinear systems and full actuation control

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Science China(Information Sciences) 2023年第11期66卷 169-184页

作者： Fei yan Mingyuan ZHANG guoxiang GU School of Information Science and Technology Southwest Jiaotong University School of Electrical Engineering and Computer Science Louisiana State University

We study adaptive control for a family of nonlinear systems, involving unknown and uncertain parameters. The proposed control law estimates the system parameters adaptively and stabilizes the closedloop system asymptotically for the initial state over any given bounded set of the state-space. Moreover,reconstruction filters are designed to obtain error residue signals and to enable the use of the least-squares algorithm for estimating the parameters, in order to achieve the convergence based on the persistent excitation condition and asymptotic linearization. The proposed methods are applicable to full actuation and under actuation control systems. Simulation studies are carried out for a pendulum system and for a third-order vehicle model, as well as control of vehicle platoons, validating the theoretical results presented in this paper.

关键词： adaptive control asymptotic stabilization full actuation and under actuation least-squares nonlinear systems

Boosting fast lithium ion storage of Li4Ti5O12 by synergistic effect of vertical graphene and nitrogen doping

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Journal of Energy Chemistry 2020年第12期51卷 372-377页

作者： yan Lin Jianbo Wu Xiaohua Huang guoxiang Pan Xinhui Xia Zhejiang Provincial Key Laboratory for Cutting Tools Taizhou University Department of Materials Chemistry Huzhou University School of Materials Science and Engineering Zhejiang University

The advancement of power-type lithium ion batteries（LIBs） mainly depends on the construction of electrodes with superior electronic & ionic conductivity. In this work, a synergistic combination of nitrogen doped LiTiO（N-LTO） nanoparticles and highly conductive vertical graphene（VG） skeleton is proposed to obtain ultrafast Li ion storage performance via a facile hydrothermal-nitridation method. The as-synthesized composite nanosheets are composed of interconnected N-LTO shell and VG core to form the final N-LTO/VG core-shell arrays, which are systematically studied as the anodes of LIBs. In virtue of the positive synergistic effect of high conductive VG backbone and nitrogen doping, overwhelming advantages including high specific surface area, superb structural stability and enhanced conductivity are achieved in the well-designed N-LTO/VG electrodes. Accordingly, the as-synthesized N-LTO/VG electrode shows outstanding high rate capacity(142.5 m Ah gat 20 C) and superior long-term cycling stability（capacity retention of 98.9% after 10000 cycles at 5 C）, better than LTO/VG electrode without N *** research provides a new strategy for the synthesis of high-performance hybrid electrodes for application in power-type LIBs.

关键词： Lithium titanate Anode Lithium ion batteries Vertical graphene High power

Revealing phase transitions and instabilities in pseudospark discharges

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High Voltage 2023年第4期8卷 819-832页

作者： Jiaqi yan Saikang Shen guoxiang Sun Weidong Ding Weizong Wang School of Astronautics Beihang UniversityBeijingChina State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina

Pseudospark discharge is a low-pressure high-voltage pulsed discharge with hollow electrodes,and the overall discharge experiences several distinctive *** instability phenomena,characterised by the sudden oscillations or distortions of discharge voltage and current,restrict the applications of pseudospark *** study presents an investigation into phase transitions and instabilities in pseudospark discharge by combining the evidences from multiple discharge waveforms,time-resolved images,electron beam current profiles,2D kinetic simulation results,and the spectral line emission of cathode *** process of a normal pseudospark discharge is firstly discussed,and the threshold conditions of the transition from the superdense glow discharge(SGD)phase to the high current phase with arc cathode spots are *** to temporal profiles and voltage-current characteristics,two types and four occurrences of instabilities are distinguished:type Ⅰ—in the pre-breakdown phase;type Ⅱ-1—in the SGD phase;type Ⅱ-2—in the transition of cathode spots propagating from cathode hole edge to cathode plane;type Ⅱ-3—in the re-initiation of spots near current *** is found that the instability of type Ⅰ is caused by the stepwise penetration of virtual anode plasma,and type Ⅱ is closely related to the cyclic nature and finite lifetime of cathode *** is induced by the fact that the decay of cathode spots is faster than the formation under certain conditions,and the existing spots are not able to provide the current required by the external *** features and the suppression methods of the instabilities are discussed based on the proposed mechanisms.

关键词： phase cathode lifetime

LARRAZA-PUTTERMAN EQUATION INCLUDING VISCOSITY AND EXTERNAL DRIVE

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Chinese Journal of Acoustics 1989年第2期8卷 163-169页

作者： yan Jiaren, HUANG guoxiang and LI Hong(Xiangtan University) Xiangtan Univ

The weak nonlinear modulation of the surface wave of a three-dimensional imcompressible fluid without rotation, which is contained in a rectangular trough is studied by using the method of multiple scales perturbation theory. The effects of viscid and external drive on the motion, which modifies the Larraza- Putterman equation, are considered. The results are consistent with that of Miles.

关键词： LARRAZA-PUTTERMAN EQUATION INCLUDING VISCOSITY AND EXTERNAL DRIVE

A MODEL EQUATION AND ITS EXACT TWO DIMENSIONAL SOLITARY WAVE SOLUTIONS FOR WATER WAVE DYNAMICS

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Chinese Physics Letters 1989年第9期6卷 393-396页

作者： HUANG guoxiang LOU Senyue Dai Xianxi yan Jiaren Department of Physics Fudan UniversityShanghai Department of Physics Xiangtan UniversityHunan

Using the method of multiple scales and considering the nearly two-dimensional modulation of the waves when the dimensionless surfacecoeffi-cient T of fluid is close to 1/3 ,we proposed a new model equation which we call the higher-order KP equation for water wave *** exact and explicit two dimensional solitary wave solutions are also given.

关键词： equation wave exact

NON-PROPAGATING SOLITARY WAVE ON SURFACE OF FLUID WITH SMALL VISCIDITY EXCITED BY EXTERNAL DRIVE

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Chinese Physics Letters 1988年第7期5卷 305-308页

作者： yan Jiaren HUANG guoxiang Department of Physics Xiangtan UniversityHunan

The expression of non-propagating solitary wave on surface of fluid with small viscidity excited by external drive has been obtained uing the method of multiple *** discussions have been made on the result obtained,wh... 详细信息

关键词： neglected discussions excited