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Plasma Science and Technology 2019年第4期21卷 99-106页

作者： Jian CHEN Tianzuo FU Heng GUO Heping LI Dongjun JIANG Mingsheng ZHOU Department of Engineering Physics Tsinghua UniversityBeijing 100084People's Republic of China

In this paper,a one-dimension particle-in-cell(PIC)code(EDIPIC)is employed to simulate the parallel-plate ion extraction process under an externally applied electrostatic field,focusing on the analysis of the influe nee of the initial electron temperature on the extracted ion fluxes to the metal plates during the ion extraction *** with previously published results,the plasma oscillations on a timescale of the electron plasma period,and the excitation of the ion acoustic rarefaction waves resulting from the plasma oscillations originating from both the negative and positive electrodes,are studied for the first *** modeling results show that both the negative and positive extractors can collect ions due to the plasma oscillations and the propagation of the ion acoustic rarefaction *** the in crease of the initial electron temperature achieved by keeping other parameters unchanged,on the one hand,both the ion speed and flux to the negative and positive plates increase,which leads to a significant decrease of the ion extraction time,while on the other hand,the ion flux to the positive plate after the formation of a Child-Langmuir sheath is much more sensitive to an increase of the initial electron temperature than that to the negative *** PIC simulation results provide a deeper physical understanding of the influence of the initial electron temperature on the characteristics of the entire ion extraction process in a decaying plasma.

关键词： low-pressure plasma decaying plasma sheath dynamics

Direct numerical simulation of passive scalar in decaying compressible turbulence

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Science China(Physics,Mechanics & Astronomy) 2004年第1期47卷 52-63页

作者： LI Xinliang FU Dexun MA Yanwen State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

The passive scalars in the decaying compressible turbulence with the initial Reynolds number (defined by Taylor scale and RMS velocity) Re=72, the initial turbulent Mach numbers (defined by RMS velocity and mean sound speed) Mt=0.2—0.9, and the Schmidt numbers of passive scalar Sc=2—10 are numerically simulated by using a 7th order upwind difference scheme and 8th order group velocity control scheme. The computed results are validated with different numerical methods and different mesh sizes. The Batchelor scaling with k -1 range is found in scalar spectra. The passive scalar spectra decay faster with the increasing turbulent Mach number. The extended self-similarity (ESS) is found in the passive scalar of compressible turbulence.

关键词： passive scalar, decaying compressible turbulence, direct numerical simulation.

decaying of Nitrogen Second Positive System by Addition of H<sub>2</sub>Gas in Air DB Discharge

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Journal of Modern Physics 2013年第2期4卷 160-167页

作者： Doaa M. El-Zeer Ahmed Samir Farouk Elakshar Abdo A. Garamoon Center of Plasma Technology Al-Azhar University Cairo Egypt Physics Department Faculty of Science Al-Azhar University Cairo Egypt

Effects of addition of H2 gas in air DB discharge on its optical and electrical characteristics have been studied. Optical emission spectroscopy is used to investigate the effect of hydrogen admixing on the emission intensity of the nitrogen second positive systems (300 - 420 nm) and the relative population density of states. An obvious decaying of the emission intensity of the nitrogen second positive bands with the introduction of H2 has been observed. It has been concluded that quenching of the nitrogen excited state is the responsible reason of this decaying. Mechanisms of excitation and ionization processes of nitrogen molecules in this mixture have been studied. Processes which are responsible for the decaying of the population density of have been reported. Addition of H2 to air improves the electrical characteristics of the DB discharge. An abrupt increasing in the electron density, reached about thirty fold at H2 flow rate of 3 L/min, as a result of increasing the ionization processes has been reported. The breakdown voltage of the discharge decreased from 1.87 kV to about 1.25 kV by the addition of H2 at flow rate of 3 L/min.

关键词： Nitrogen Second Positive DBD H2 Addition Intensity decaying

Boundary conditions for the bending of a piezoelectric beam

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Science China(Physics,Mechanics & Astronomy) 2008年第7期51卷 847-856页

作者： GAO Yang1, XU SiPeng2 & ZHAO BaoSheng3 1 College of Science, China Agricultural University, Beijing 100083, China 2 College of Engineering, Ocean University of China, Qingdao 266071, China 3 School of Mechanical Engineering, University of Science and Technology Liaoning, Anshan 114044, China College of Science China Agricultural University Beijing China College of Engineering Ocean University of China Qingdao China School of Mechanical Engineering University of Science and Technology Liaoning Anshan China

For beam bending in transversely isotropic piezoelectric media, the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the beam of general edge geometry and loadings. By generalizing the method developed by Gregory and Wan, a set of necessary conditions on the edge-data for the existence of a rapidly decaying solution is established. The prescribed edge-data of the beam must satisfy these conditions in order that they could generate a decaying state within the beam. When stress and mixed conditions are imposed on the beam edge, these decaying state conditions for the case of bending deformation of piezoelectric beam are derived explicitly. They are then used for the correct formulation of boundary conditions for the beam theory solution (or the interior solution). Besides, an analytical solution of elastic beam is formulated to verify validity of our boundary conditions. For the stress data, our boundary conditions coincide with those obtained in conventional forms of beam theories. More importantly, the appropriate boundary conditions with two sets of mixed edge-data are obtained for the first time.

关键词： boundary conditions beam bending piezoelectric media decaying states regular states

Large time behavior of solutions for critical and subcritical complex Ginzburg-Landau equations in H^1

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Science China Mathematics 2003年第1期46卷 64-74页

作者：王保祥 Department of Mathematics Peking University

Considering the Cauchy problem for the critical complex Ginzburg-Landau equation in H1(Rn), we shall show the asymptotic behavior for its solutions in C(0, ?;H1(Rn)) ∩ L2(0, ?;H1,2n/(n-2)(R2)), n≥3. Analogous result... 详细信息

关键词： complex Ginzburg-Landau equation, critical power in H1, large time decaying estimate, time-space Lp-Lp' estimate at endpoint.

NONLINEAR COMPUTATIONAL INSTABILITY IN CALCULATION OF DISCONTINUOUS SOLUTION

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中国科学院研究生院学报 1991年第1期8卷 23-31页

作者： Ji Zhongzhen, Guo Dongjian(LASG, Institute of Atmospheric Physics, Academia Siniea)Ji Suzhen(Computer Center, Shanxi Institute of Meehancal Engineering, Xian, China)

Starting from one-dimensional nonlinear advecting equations, this paper has probed the energy properlies of discontinuous solutions, investigated that it is suitable to adopt energy decaying scheme to compute discontinuous solutions, compared and testified several difference schemes with dissipation effects, pointed out that it is easy to bring about nonlinear stabilities in doing discontinuous computation, and listed several better-effect schemes.

关键词： nonlinearinstability energy decaying scheme discontinuous solution

The Behavior of the Hydrogen Atom under Different Potential Well

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Optics and Photonics Journal 2019年第5期9卷 60-73页

作者： Wei-Xing Xu Newtech Monitoring Inc. Oshawa Ontario Canada

In this work we studied the behavior of hydrogen atom under different potential well and found that with decreasing the distance between the electron and proton, the more multiple interaction terms start to take effect and the potential well becomes more and more sensitive to the distance between the electron and proton. Based on these results, the potential well for the neutron decaying is determined. Furthermore, the general topics, such as the origin of nuclear energy, the fundamental forces in the nature and the matter with negative mass, also are discussed. At the end of this work, the duality model of our universe is put forth.

关键词： Neutron decaying Multiple Interactions The Negative Mass The Handedness The Gravity The Fundamental Forces

Striding On The Waste Land

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海外英语 2019年第14期 230-231页

作者：乔晓芳中国劳动关系学院

Living in modern world,the civilization is highly *** beings are living an unprecedented prosperous life,but the spiritual waste land is still invisibly *** mechanism alienates people even more serious than what it is in the Waste *** the fighting against the Waste land to salvage it as well as ourselves is endless and *** Waste Land thus is not decaying and hopeless,but natural and common as at any ***,the new conditions of life required“a new discipline of suffering”.So we should do as the poet does:accept reality,positively indulge in it to feel and experience fully,to suffer *** we will feel that The Waste Land brings us not a melancholy mood,but a positive encouragement for the salvage of ourselves.

关键词： the waste land decaying feel experience suffer salvage