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941.
通过一理想实验导出爱因斯坦质能关系式。  相似文献   
942.
绕组故障时异步电机定子电磁振动频谱的计算   总被引:1,自引:1,他引:0  
本文阐述在绕组故障和非故障情况下异步电机定子径向电磁振动频谱的计算方法,这一方法可以全面考虑各种气隙磁场谐波的影响,并对一台绕线式异步电机在定子绕组发生相间短路及正常运行时定子电磁振动的频谱作了计算和比较.  相似文献   
943.
核磁共振中的磁体设计有许多方案,但是要使磁体体积小、重量轻、均匀区大、稳定性好,将面临一系列的问题. 而这些问题的解决主要依赖于电磁场计算. 文中首先阐述这些问题,然后对方案进行优化分析计算,从中找出一个最佳的解决方案. 采用本方案研制出来磁体,我们研制成功了便携式核磁共振岩样分析仪. 经过多次的现场实验测试表明由该磁体构成的磁共振岩样分析仪的稳定性高、重复性好、满足现场恶劣的环境要求.  相似文献   
944.
In the framework of Nonlinear Elasticity, the asymptotic behavior of the free energy of a martensitic material is studied as the height of the sample tends to zero. The effective thin film energy is identified in terms of parametrized probability measures, which allows for a justification of the kinematic compatibility conditions proposed in Bhattacharya and James' theory of thin films of martensitic materials, in the absence of higher order interfacial energy contributions to the three-dimensional bulk energy.  相似文献   
945.
In this paper, we propose a GL method for solving the ordinary and the partial differential equation in mathematical physics and chemics and engineering. These equations govern the acustic, heat, electromagnetic, elastic, plastic, flow, and quantum etc. macro and micro wave field in time domain and frequency domain. The space domain of the differential equation is infinite domain which includes a finite inhomogeneous domain. The inhomogeneous domain is divided into finite sub domains. We present the solution of the differential equation as an explicit recursive sum of the integrals in the inhomogeneous sub domains. Actualy, we propose an explicit representation of the inhomogeneous parameter nonlinear inversion. The analytical solution of the equation in the infinite homogeneous domain is called as an initial global field. The global field is updated by local scattering field successively subdomaln by subdomain. Once all subdomains are scattered and the updating process is finished in all the sub domains, the solution of the equation is obtained. We call our method as Global and Local field method, in short , GL method. It is different from FEM method, the GL method directly assemble inverse matrix and gets solution. There is no big matrix equation needs to solve in the GL method. There is no needed artificial boundary and no absorption boundary condition for infinite domain in the GL method. We proved several theorems on relationships between the field solution and Green's function that is the theoretical base of our GL method. The numerical discretization of the GL method is presented. We proved that the numerical solution of the GL method convergence to the exact solution when the size of the sub domain is going to zero. The error estimation of the GL method for solving wave equation is presented. The simulations show that the GL method is accurate, fast, and stable for solving elliptic, parabolic, and hyperbolic equations. The GL method has advantages and wide applications in the 3D electromagnetic (EM)  相似文献   
946.
A scheme for implementing 2-qubit quantum controlled phase gate (QCPG) is proposed with two superconducting quantum interference devices (SQUIDs) in a cavity. The gate operations are realized within the two lower flux states of the SQUIDs by using a quantized cavity field and classical microwave pulses. Our scheme is achieved without any type of measurement, does not use the cavity mode as the data bus and only requires a very short resonant interaction of the SQUID-cavity system. As an application of the QCPG operation, we also propose a scheme for generating the cluster states of many SQUIDs.  相似文献   
947.
We propose a very simple method to determine the electrical tip-surface force in Atomic Force Microscopes used to study the electrical properties of metallic or insulating materials; the analysis of the measurements as well as determination of the appropriate experimental procedures requiring an analytical model of the tip-surface capacitance. The comparison of force expressions obtained by this method with those obtained by exact derivation in the case of the sphere-infinite plane system shows very good agreement. This method is then applied to determine the tip-surface force, the real shape of the tip being introduced in the derivation. The obtained expression is compared to experimental and numerical data. We emphasize that this method is very general and can be applied to any axially symmetric capacitor. Received: 17 June 1997 / Received: 16 September 1997 / Accepted: 7 November 1997  相似文献   
948.
Chitin–cellulose blends dissolved in dimethylacetamide containing LiCl (7% w/w) have been studied in a wide concentration range, from very dilute solutions to medium concentrations and up to solid films (absence of diluent). The intrinsic viscosities at various chitin–cellulose ratios, as well as the phase diagram behavior, imply a good compatibility between the components. The result is confirmed by the infrared measurements on solid films. The lack of anisotropic phase formation in chitin–diluent binary solutions and the anomalous trend of v′CH–CE line on the phase diagram are both interpreted on the basis of aggregation phenomena.  相似文献   
949.
甘永超  吴美钧 《光子学报》1995,24(5):472-475
在Dirac工作的基础上对电磁场作了更进一步的分解───电磁场按光子对应分解。这一分解的成功找到了经典电磁场与量子电磁场的一种基元对应关系,进而,揭示出电磁场在量子化之前就具有结构上的颗粒性。  相似文献   
950.
天线在随机脉动压力作用下的运动感应电磁噪声   总被引:2,自引:0,他引:2  
研究了天线在随机脉动压力作用下的运动感应电磁噪声,包括:随机脉动压力谱密度计算公式的建立;电极对天线运动感应电磁噪声的产生机理与计算方法;仿真结果及分析。研究结果对于水下通信有重要的应用意义。  相似文献   
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