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为了研究电磁轨道炮电枢和轨道之间的接触阻抗变化,本文通过建立U型电枢和简单轨道间的磁扩散模型,根据麦克斯韦方程组计算电枢和轨道间的接触压力与电磁推力。在考虑接触形式、接触压力的影响下根据霍姆电接触模型计算电枢运动过程中的接触电阻变化,并通过对电枢的动力学分析引入速度趋肤效应引起的附加接触电阻变化。采用Comsol Multiphysic有限元分析软件对电枢进行力学分析,然后通过该软件与MATLAB联合编程得到在电枢运动过程中接触电阻的变化曲线。发现接触阻抗的变化值为0.22~4.5 mΩ,并且电枢速度对其变化的影响较大。 相似文献
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目的 探讨SF-36在慢性肾衰患者生存质量评价中的作用.方法 采用简明健康调查问卷(SF-36)对89名慢性肾衰患者进行问卷调查.在SPSS支持下,进行分半信度、秩相关和多元线性回归分析,同时对慢性肾衰患者的生存质量进行评价.结果 SF-36用于评价慢性肾衰患者生存质量的分半信度为0.976.经多元线性回归分析医疗费用和收入水平被选入回归方程.慢性肾衰患者的生存质量普遍下降,并随着病情严重度的加重而降低.结论 SF-36可在一定程度上评价慢性肾衰患者生存质量,早期正规治疗可以提高慢性肾衰患者的生存质量. 相似文献
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Dynamics of erbium-doped fibre laser with optical delay feedback and chaotic synchronization 总被引:1,自引:0,他引:1
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The dynamical behaviour of the erbium-doped fibre single-ring laser
with an optical delay feedback is discussed. Simulation shows that as
the delay
rate increases, the
lasing light displays period-doubling which leads to chaos and via reverse
period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also
observed. The identical synchronization based on
chaos in this ring laser is demonstrated by
numerical simulation. 相似文献
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A Novel Method to Calculate the Initial Phase Difference between the Two Fibre Arms of Laser Homodyne Iuterferometer
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We suggest a novel method to calculate the initial phase difference between two fibre arms of a laser homodyne interferometer. Put the two fibre arms in a temperature controller, whose short term stability is 0.02° C (measured in an hour), then measure the interference photocurrent and the photocurrents from the two fibre arms at a fixed temperature. With these three photocurrents we can calculate the value of the initial phase difference. We set up a simple laser homodyne interferometer to test the theory. The experimental results are repeatable and the measurement precision is about 0.04°. It is theoretically and experimentally proven that this method is potentially easy and practical. 相似文献