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排序方式: 共有2578条查询结果,搜索用时 15 毫秒
991.
This paper presents the design of a permanent magnet (PM) synchronous motor with the magnets laid flush in slots let into the rotor surface, called inset magnet rotor. The finite element field analysis coupled with the drive circuit equations are briefly discussed for obtaining the motor performance. Experimental results obtained are in good agreement with the finite element analysis. 相似文献
992.
This paper studies the initial boundary value problem of fourth order wave equation with dispersive and dissipative terms. By using multiplier method, it is proven that the global strong solution of the problem decays to zero exponentially as the time approaches infinite, under a very simple and mild assumption regarding the nonlinear term. 相似文献
993.
近似黎曼解对高超声速气动热计算的影响研究 总被引:3,自引:1,他引:2
高超声速流场计算一般采用TVD型格式,这些格式中,大多采用了不同形式的近似黎曼解. 通过分析和数值验证,论述了激波捕捉格式中近似黎曼解的耗散性质,说明其对高超声速热流计算的影响. 数值实验证明,采用低耗散格式可大大提高热流计算精度,降低热流计算对网格的依赖程度,从而获得精确的热流数值解. 相似文献
994.
995.
阐述了近年来国内外印制电路板中六价铬Cr(Ⅵ)的测定方法,主要包括分光光度法、柱后衍生法、离子色谱-电感耦合等离子体质谱联用(IC-ICP-MS)等方法,未来印制电路板中六价铬的测定方法一定向着新技术联用方向发展。 相似文献
996.
With the help of scattering-matrix method, the acoustic phonon ballistic transmission and the thermal conductivity are studied detailedly in a four-terminal structure. We find that the transmission coefficients and the reduced thermal conductance for each region sensitively depend on geometric parameters, and are of quantum character, but the reduced total thermal conductance for all regions seems independent of structure parameters when the temperature is not very low. Our results show that one can control the thermal conductivity for each region to match practical requirements in devices by adjusting the geometric parameters. 相似文献
997.
《Physics letters. A》2020,384(24):126452
Mg-Al layered double hydroxides/micro-arc oxidation (Mg-Al LDHs/MAO) composite coating on AZ31 magnesium alloy is fabricated by hydrothermal treatment. Corrosion system is described by ideal equivalent circuit, in which each layer or interface is regarded as the corresponding electronic component. The optimal equivalent circuit is determined by the minimum total error area of electrical parameters. Error areas of phase angle and modulus for experimental and fitting data are calculated for the selected four different kinds of circuit models such as EC1, EC2, EC3 and EC4. The results show that circuit model EC2 is the best because its total error is 1/2, 2/19 and 1/15 of error values for other three kinds of circuit models, respectively. This work reveals that the optimal equivalent electrical circuit can well reflect corrosion system of Mg-Al LDHs/MAO composite coating with the help of electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). 相似文献
998.
999.
This paper investigates the outage performance of simultaneous wireless information and power transfer (SWIPT)-enabled relay networks with the decode-and-forward relaying protocol, where the effect of the energy triggering threshold at the relay on the system performance is considered. The closed-form expressions of the system outage probability and throughput are derived in Rician channel fading. Monte Carlo Simulation method is used to verify the accuracy of the derived closed-form expressions. The effects of some system parameters on the system performances are discussed via simulations, which show that the system outage probability increases with the increase of the minimum transmission rate required by the users and also decreases with the increase of the energy conversion efficiency. Besides, the system throughput increaseswith the increment of the transmit power of the source node, as well as the energy conversion efficiency. Additionally, the outage performance of the system with the equal two-hop distance is better than that of the system with unequal two-hop distance. 相似文献
1000.
Timothy Child Owen Sheekey Silvia Lüscher Saeed Fallahi Geoffrey C. Gardner Michael Manfra Joshua Folk 《Entropy (Basel, Switzerland)》2022,24(3)
Previous measurements utilizing Maxwell relations to measure change in entropy, S, demonstrated remarkable accuracy in measuring the spin-1/2 entropy of electrons in a weakly coupled quantum dot. However, these previous measurements relied upon prior knowledge of the charge transition lineshape. This had the benefit of making the quantitative determination of entropy independent of scale factors in the measurement itself but at the cost of limiting the applicability of the approach to simple systems. To measure the entropy of more exotic mesoscopic systems, a more flexible analysis technique may be employed; however, doing so requires a precise calibration of the measurement. Here, we give details on the necessary improvements made to the original experimental approach and highlight some of the common challenges (along with strategies to overcome them) that other groups may face when attempting this type of measurement. 相似文献