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研究了多电荷碳离子分别与中性氢原子或氦原子碰撞的电荷损失截面,同时计算了多电荷碳离子的电势函数和电子动量分布,其中电荷数为5的碳离子的截面数据与Shirai等人的计算结果符合得相当好。所导出的计算公式和编制的计算程序可以推广计算任何一个多电荷离子Aq+与H或He碰撞的电荷损失截面,因而具有一定的普适性。 相似文献
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从半径映象函数出发,给出了“守恒-映象”电荷沉积公式中积分限的确定方法和电荷沉积精度的确定方法,从而使“守恒-映象”电荷沉积方法成为计算电流密度和电荷密度的一种切实可行的精确的电荷沉积方法。 相似文献
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基于迭代变电荷方法,用分子动力学模拟了非晶态石英的结构与振动特征.首先利用熔化-猝火方法得到了非晶石英的平衡结构.在此基础上获得了体系不同原子对之间的对关联函数、键角分布函数和振动频谱等,结果与实验数据均符合较好.变电荷方法的计算结果表明,非晶石英体系内粒子的电荷与石英晶体内粒子电荷显著不同,并且出现了较大的涨落.
关键词:
分子动力学
变电荷
非晶石英 相似文献
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以Du Pont公司的商用Teflon FEP A型薄膜为例,通过热脉冲技术、等温表面电位衰减测量和开路热刺激放电电流谱分析等实验结果,讨论了经常温和高温电晕充电后样品厚度对薄膜驻极体的沉积电荷密度、薄膜驻极体的内电场、体电导率以及电荷储存稳定性的影响.通过热脉冲技术组合电导率温度曲线的测量,研究了在不同温度条件下样品厚度对沉积电荷层的平均电荷重心移动的影响.结果表明:在充电参数一定的条件下,随着膜厚的降低,储存电荷密度上升,但电荷稳定性有所下降.因此,合理地调控薄膜厚度,可以有效地优化驻极体的电荷储存能
关键词:
厚度
驻极体
电荷储存能力
电荷稳定性 相似文献
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利用2.5维KARAT软件对高功率离子束在偏压电荷收集器内部的电荷输运过程进行PIC数值模拟,模拟结果表明在偏压电荷收集器内部电荷中和而电流不中和。在模拟中考虑了收集器的几何尺寸和离子束密度,因此模拟结果比一维数值计算的结果更为可靠。同时还模拟了偏置电压与电荷收集器离子收集效率之间的关系,对于峰值能量为500keV的高功率离子束,偏压为-800V即可满足测量要求,这一结果与实验吻合较好。 相似文献
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N. S. Savenkova R. T. Kuznetsova I. N. Lapin V. A. Svetlichnyi G. V. Mayer P. A. Shatunov 《Optics and Spectroscopy》2005,99(5):751-758
The spectral and luminescent properties of some derivatives of tetraphenylporphyrin are studied at different concentrations of these compounds; the spectra of neutral and ionic forms are interpreted; and the quantum yields of ordinary and, in some cases, short-wavelength fluorescence from highly excited states are determined. The spectra of transient absorption from excited states, existing in the time range of tens of nanoseconds, are measured, and the quantum yields of formation of triplet molecules are estimated. Hypotheses regarding the mechanism of phototransformations of some porphyrins in chloroform are put forth. 相似文献
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Travelling solitary wave solutions for the generalized Burgers--Huxley equation with nonlinear terms of any order
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In this paper, the travelling wave solutions for the generalized
Burgers--Huxley equation with nonlinear terms of any order are
studied. By using the first integral method, which is based on the
divisor theorem, some exact explicit travelling solitary wave
solutions for the above equation are obtained. As a result, some
minor errors and some known results in the previousl literature
are clarified and improved. 相似文献
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In this paper,we investigate some exact soliton solutions for a generalized variable-coefficients nonlinear Schrdinger equation (NLS) with an arbitrary time-dependent linear potential which describes the dynamics of soliton solutions in quasi-one-dimensional Bose-Einstein condensations. Under some reasonable assumptions,one-soliton and two-soliton solutions are constructed analytically by the Hirota method. From our results,some previous one-and two-soliton solutions for some NLS-type equations can be recovered by some appropriate selection of the various parameters. Some figures are given to demonstrate some properties of the one-and the two-soliton and the discussion about the integrability property and the Hirota method is given finally. 相似文献
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两部美国大学物理教材对我们教学改革的启示 总被引:9,自引:1,他引:8
介绍了美国两部大学物理教材的特点,分析了美国教材在教学内容、教学方法、教学手段现代化方面的特色,为我们的教学改革提供一些可供借鉴的经验。 相似文献
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《Physics letters. A》1997,236(4):319-321
New explicit and exact travelling wave solutions to some nonlinear equations are obtained. For some chosen parameters in the nonlinear equations, constants in the explicit solutions are given numerically. 相似文献
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Recently,self-sustained oscillatory genetic regulatory networks(GRNs) have attracted significant attention in the biological field.Given a GRN,it is important to anticipate whether the network could generate oscillation with proper parameters,and what the key ingredients for the oscillation are.In this paper the ranges of some function-related parameters which are favorable to sustained oscillations are considered.In particular,some oscillatory motifs appearing with high-frequency in most of the oscillatory GRNs are observed.Moreover,there are some anti-oscillatory motifs which have a strong oscillation repressing effect.Some conclusions analyzing these motif effects and constructing oscillatory GRNs are provided. 相似文献
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The peak, integrated and standard intensities of some prominent Raman lines in twelve alcohols are estimated. The standard intensities of the lines due to some characteristic bonds in various alcohols are compared and large variations observed. 相似文献
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质子直线加速器设计研究 总被引:1,自引:0,他引:1
当前质子直线加速器发展的两个重要方向是强流质子直线加速器和小型质子直线加速器.前者主要用于核能领域,后者主要用于质子治疗.两类加速器有着共同的特点:1.采用一些新型加速结构,它们是传统结构的组合和发展;2.加速小发射度的质子束;3.加速器应有高度的可靠性.但前者的建造难度远大于后者,它还要求具有很低的束流损失率和尽可能高的能量利用效率.研究了两类加速器设计中的一些重要问题,提出了一些设计方案. 相似文献
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