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101.
102.
介绍了基于高速大功率反向开关晶体管(RSD)的磁压缩固态脉冲电源试验平台,就RSD状态电流及磁压缩脉冲电流的波形特征对检测环节高需求的问题,研究了罗氏(Rogowski)线圈传感头的频率特性,在对比已有传感头信号处理方法的基础上,给出了一种新型结构的自积分与外积分复合式罗氏线圈的设计过程和参数选取方法,在保证传感器具有1 mV/A灵敏度的前提下,将传感器的工作频带从低频拓宽到线圈的自然角频率。给出了二级磁压缩网络放电的负载电流实验波形及RSD开关的触发、导通电流波形,验证了该罗氏线圈传感器能够满足本固态脉冲电源中的RSD开关状态电流高精度检测和负载电流的高频检测要求。 相似文献
103.
Global stabilization of the oscillating eccentric rotor 总被引:1,自引:0,他引:1
The oscillating eccentric rotor has been widely studied to model resonance capture phenomena occurring in dual-spin spacecraft and rotating machinery. This phenomenon arises during spin-up as a resonance condition is encountered. We consider the related problem of rotor despin. Specifically, we determine nonlinear feedback control laws that not only despin the rotor but also bring its translational motion to rest. These globally asymptotically stabilizing control laws are derived using partial feedback linearization and integrator backstepping schemes. For the case in which the oscillating eccentric rotor is excited by a translational sinusoidal forcing function, the control law is shown to attenuate the amplitude of the translational oscillation.Research supported in part by the Air Force Office of Scientific Research under Grant F49620-92-J-0127.Research supported in part by NSF Grant MSS-9309165. 相似文献
104.
本文从理论上论述了多功能痕迹物证摄影仪的基本结构和使用方法。利用现有的近距摄影装置、球形摄影仪、彩色偏光镜和偏振摄影灯等设备,对常见痕迹物证进行模拟拍摄实验证明是可行的。解决了拍摄光滑金属物体表面遣留痕迹时的反光干扰问题和加强反差摄影时光照角度不能连续可调的问题。 相似文献
105.
Lang-yangHuang Wen-pingZeng Meng-zhaoQin 《计算数学(英文版)》2003,21(6):703-714
The Hamiltonian formulations of the linear “good“ Boussinesq (L.G.B.) equation and the multi-symplectic formulation of the nonlinear “good“ Boussinesq (N.G.B.) equation are considered. For the multi-symplectic formulation, a new fifteen-point difference scheme which is equivalent to the multi-symplectic Preissmann integrator is derived. We also present numerical experiments, which show that the symplectic and multisymplectic schemes have excellent long-time numerical behavior. 相似文献
106.
A discrete total variation calculus with variable time steps is
presented for mechanico-electrical systems where there exist
non-potential and dissipative forces. By using this discrete
variation calculus, the symplectic-energy-first integrators for
mechanico-electrical systems are derived. To do this, the time step
adaptation is employed. The discrete variational principle and the
Euler--Lagrange equation are derived for the systems. By using this
discrete algorithm it is shown that mechanico-electrical systems are
not symplectic and their energies are not conserved unless they are
Lagrange mechanico-electrical systems. A practical example is
presented to illustrate these results. 相似文献
107.
This paper critically analyses and simulates the circuit configuration of the integral gated mode single photon detector which is proposed for eliminating the transient spikes problem of conventional gated mode single photon detector. The relationship between the values of the circuit elements and the effect of transient spikes cancellation has been obtained. With particular emphasis, the bias voltage of the avalanche photodiode and the output signal voltage of the integrator have been calculated. The obtained analysis results indicate that the output signal voltage of the integrator only relates to the total quantity of electricity of the avalanche charges by choosing the correct values of the circuit elements and integral time interval. These results can be used to optimize the performance of single photon detectors and provide guides for the design of single photon detectors. 相似文献
108.
针对在阳加速器上进行Z箍缩实验时存在的同步精度低的问题,研究了一套同步触发信号取自加速器输出电流的技术。利用加速器工作电流波形与物理实验现象间的固有延迟时间关系来判断同步的时刻,时间关联的精度可到达ns量级。为了防止加速器对测量系统的影响,根据延迟时间长短的不同情况还研究了光电隔离方式和光纤传输方式,解决了在阳加速器平台上的电磁干扰问题,实现了在阳加速器上进行可靠物理实验的精密测量工作;本触发方式配合高速分幅相机的应用,稳定而可靠地以10 ns间隔、3 ns曝光时间拍摄到了Z箍缩的发展过程。 相似文献
109.
用广义Poisson括号直接定义的广义Hamilton系统是经典Hamilton系统的一种推广。由于它的维数没有限制,同时它又保持了经典Hamilton系统的主要性质,因此具有更大的普遍性和广泛的应用前景。本文简要介绍了广义Hamilton系统理论的发展历史、基本概念和研究现状。 相似文献
110.
Dongya Bai Dr. Tengfei Yan Shi Wang Dr. Yanbo Wang Dr. Jiya Fu Prof. Xiaomin Fang Dr. Junyan Zhu Prof. Junqiu Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(32):13704-13709
Ligand responsiveness is one of the typical mechanisms in biological organization to trigger sophisticated channel switching. Here, we report a new type of helical trimer which can undergo transition between a hollow single helix and an intertwined double helix with no cavity by complexation and decomplexation of Cu ions. In addition, the one dimensional (1D) hollow helical tubes spontaneously generated from single helices via π-π interactions embedded into the lipid bilayers and displayed satisfactory channel stability and efficiency. With the addition of CuI ions and further extraction with ammonia, the disassembly and reassembly of 1D hollow helical tubes gave rise to the reversible switching of channel activity in situ inside the bilayers. The synthetic helical system provides the first model of reversible ligand-gated ion channel by means of dynamic transition between single and double helices, which will be available for developing intelligent artificial nanochannels for potential biological and medicinal applications. 相似文献