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41.
尹彤  廖阳 《冶金自动化》1997,21(3):38-40
介绍了开发的全数字交流伺服系统的组成、基本原理及软、硬件结构。通过与模拟交流伺服系统的比较,说明了全数字交流伺服系统可编程能力强、系统稳定性好、系统性能提高等特点。  相似文献   
42.
How to Control Robots Interacting with Dynamic Environment   总被引:7,自引:0,他引:7  
The goal of this paper is to shed light on the control problem of constrained robot motion from the aspect of the dynamical nature of the environment with which the robot is in contact. Therefore, the criticism of traditional hybrid control which allows position/force feedback loops to split into independent control with respect to position and force, is not the main point we want to make. Reference to the papers written by the founders of hybrid control and their numerous followers served only to better understand the reason and motivation for suggesting a different approach to control of robots interacting with environment.The paper has a predominantly review character, based on recently published work. It also contains some new, unpublished results in the framework of the unified approach to the position/force control of robots, proposed by the present author and his co-workers. By pointing to the possibility of introducing an environment dynamics in the contact tasks of the machining type, the author emphasizes that the proposed dynamically interactive control can be applied to a completely different class of tasks, in which a contact is made between the system (constructions or structure) and very specific kinds of dynamic environments.  相似文献   
43.
In the absence of a bulk diffusion effect, it is shown for the first time that the impedance spectra for the chlorine evolution reaction on a rotating thin ring electrode comprise three consecutive semicircles in the capacitive half of the complex plane. The first (highest frequency) semicircle is due to the charge-transfer resistance for chloride discharge and the simultaneous chlorine adsorption coupled to the double-layer capacitance. The second semicircle (around 5 Hz) is due to the adsorption and desorption of a chlorine intermediate. The third (lowest frequency, around 0.5 Hz) semicircle is due to the relaxation of surface oxygen species. The impedance data allow the steps of the overall reaction to be examined individually. On a Pt surface the rate of chloride discharge and simultaneous chlorine adsorption (the admittance of the first semicircle) is first order with respect to chloride concentration and has a potential-dependence close to 58 mV/decade. The rate of the adsorption and desorption process (the admittance of the second semicircle) is second order with respect to chloride concentration, and has a potential dependence close to 30 mV/decade. The time constant for the adsorption/desorption processes is ca 20 ms, independent of electrode potential in the range studied. These features are consistent with a mechanism in which a faster discharge reaction (Cl Clad + e) is followed by a slower surface combination reaction (2Clad → Cl2), but inconsistent with mechanisms in which ion + atom desorption is predominant, the initial chloride discharge is slow, or a unipositively charged chlorine species is involved.  相似文献   
44.
叠后地震剖面的线性化波阻抗反演   总被引:4,自引:0,他引:4  
本文提出了由井旁道出发逐道进行的叠后地震剖面的线性化波阻抗反演方法。每一道反演采用逐次线性化对波阻抗进行修正,反演的纵向分辨率为一个采样时间间隔,并以合成记录道与实际地震道的相似系数作为迭代收敛准则,已处理的地震道波阻抗作为下一道反演初始值。实际资料处理表明,该方法具有较高的分辨率和运算速度快的优点。  相似文献   
45.
A new type of arc plasma reactor with 12-phase alternating current (AC) discharge for synthesis of carbon nanotubes (CNTs) is proposed. A couple of six discharge electrodes by which have mutually electrical connection between them to enlarge the high-temperature regions in the reactor are arranged to three-dimensional locations. A new method of CNTs fabrication by this reactor, which accomplishes to enlarge the suitable growth region in high purity and at high yield, was developed.  相似文献   
46.
从传输线模型出发,分析了二平行直导线间串扰的低频模型有效性,得出允许3dB误差的条件下,低频模型在工程计算串扰中的电学短线和频率足够小的具体限值;同时分析了端接阻抗大小对串扰耦合的影响。对电磁兼容性中的串扰耦合的工程应用有实际指导和参考意义。  相似文献   
47.
在研究光泵腔式NH3分子远红外激光频谱特性的基础上,应用量子系统的密度矩阵理论,采用迭代法和增益迭加原理计算了以TEA CO2-10R(8)泵浦的NH3分子腔式远红外激光器的最佳工作参数。提供了光泵腔式NH3分子远红外激光器(腔式NH3-OPFIRL)的工作参数之间的关系曲线。  相似文献   
48.
低压宽温高频铝电解电容器工作电解液   总被引:3,自引:1,他引:2  
在传统的己二酸铵/乙二醇加水体系中,通过增加水的含量实现高电导率,同时在电解液中添加多种有机高分子物质形成复合添加剂,改善工作电解液的高温稳定性,使电容器上限工作温度扩展到105℃,形成高频宽温低阻抗工作电解液。  相似文献   
49.
非晶软磁合金的巨磁阻抗效应及应用   总被引:3,自引:2,他引:1  
钟智勇  陈伟元 《功能材料》1997,28(3):224-227
近来在FeCoSiB等Co基非晶体丝带中现了巨磁阻抗效应,由于在一小的直流纵向偏置场下该效应能使丝带两端的交流电压发生大而灵敏的变化,因而在磁记录头和传顺技术中具有巨大的应用科学潜能,受到各国学者的关注,本文简单介绍了巨磁阻抗效应的来源,并综述了近年来非晶体软磁合金材料的的巨磁阻抗效应及应用的研究进展,文章最后说明了尚待深入解决的问题。  相似文献   
50.
The corrosion of low carbon steel in natural sea-water is characterized by the formation and growth of compact and thick layers composed of oxides, insoluble salts and organic materials. These layers are the result of corrosion processes induced by local environmental conditions, water oxygen supply; ionic species; bacteria and organic matter. The exchange of various species (ions, molecules, gas) between sea-water and the rust layers or the metal depends both on the kinetics of the Faradaic reactions of the entities with either the oxides or the metal, as well as on their transport properties through the different strata of the rust layers. In this work, an impedance study was carried out using the 4-electrodes cell arrangement with corrosion products picked up on steel sheet piling immersed for 25 years and analyzed as free standing membranes. This new approach is a good way to reach the specific transport and transfer properties of the oxide without being blurred by the metal influence. The physical model developed in this work was based on a transmission line, and accurately described the experimental diagrams. The electronic resistivity of the oxide layer, its porosity, the mean pore size and the reaction kinetics parameters could be determined from the fittings.  相似文献   
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