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由王以贞编著的《实用磁路设计》一书已由天津科学技术出版社出版。 作者在天津电声器材厂从事扬声器的技术工作已经三十多年了。十年前曾在厂内讲授编写《扬声器概论》,在国内电声界有一定影响,其中有磁路设计的章节。1986年,东北工学院、辽宁机械工程学会举办“磁路设计讲座”,请作者主持。当时这个“磁路设计讲座”的讲义就是现在这本《实用磁路设计》的前身。 相似文献
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The properties of spherical dilaton black hole spacetimes are investigated through a study of their geodesics. The closed and non-closed orbits of test particles are analysed using the effective potential and phase-plane method. The stability and types of orbits are determined in terms of the energy and angular momentum of the test particles. The conditions of the existence of circular orbits for a spherical dilaton spacetime with an arbitrary dilaton coupling constant α are obtained. The properties of the orbits and in particular the position of the innermost stable circular orbit are compared to those of the Reissner-Nordstrom spacetime. The circumferential radius of innermost stable circular orbit and the corresponding angular momentum of the test particles increase for α≠ 0. 相似文献
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As is well known, the exact evolution equation of the curvature perturbation plays a very important role in investigation of the inflaorresponding exacttion power spectrum of the flat universe. However, the c extension for the non-flat universes has not yet been given clearly. Interest in the non-flat, specially closed, universes has been aroused recently. The need for this extension is pressing. We start with the most elementary physical consideration and obtain finally this exact evolution equation of the curvature perturbation for the non-flat universes, as well as the evolutionary controlling parameter and the exact expression of the variable mass in this equation. We approximately perform a primitive and immature analysis on the power spectrum of non-flat universes. This analysis shows that the exact evolution equation of the curvature perturbation for the non-flat universes is very complicated, and we need to carry out many numerical and analytic works for this new equation in the future to judge whether the universe is fiat or closed by comparison of theories with observations. 相似文献
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Effects of Wall Ablation on the Trigger Process in Two—Gap Capillary Plasma Generator 总被引:1,自引:0,他引:1 下载免费PDF全文
XIASheng-Guo LIUKe-Fu PANYuan HUXi-Wei 《中国物理快报》2003,20(6):873-876
Two-gap capillary plasma generator is a realistic alternative to the conventional capillary in electrothermal launchers. It is designed to accomplish two goals: repetitive operation and a compact power supply system in which capillary itself serves as a closing switch. A theoretical model is proposed to investigate the trigger process of this kind of generator. Both ablation case and no ablation case are considered. Trigger delay time is also theoretically analysed. The calculation shows that capillary wall ablation can greatly change the behaviour of trigger discharge arc and plasma flow generated. Trigger delay time can be drastically shortened. 相似文献
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1载流圆环在匀强磁场中的受力情况 半径为r0,通以电流I的弹性圆环,放在光滑的水平面上,磁感强度为B0的匀强磁场垂直穿过圆环,如图1所示. 相似文献
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当改变能量、位置或场强等参数时,电磁场中里德堡态的原子、分子和离子等体系将出现分岔现象,从而导致波函数在分岔点附近发散,半经典闭合轨道理论不再适用.本文分析并计算了平行电磁场中的H-光剥离电子轨道的分岔现象,并采用统一近似的方法进行定域修正,从而消除了分岔点的奇异性,得到了合理的光剥离电子流的分布. 相似文献