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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
932.
A novel method of computing the nonlinear differential equations relating to the transient behaviour of an induction motor using a polynomial series, is presented. The stator and rotor currents and the angle of rotation are expressed as polynomial series dependent on time. These are then substituted into the differential equations of the induction motor to compute the polynomial coefficients and, consequently, the transient quantities. Since the equations are nonlinear, the computations are carried out using the step-by-step method. The stator and rotor currents, speed and torque are calculated for acceleration and braking conditions. The results are compared both analytically and experimentally. 相似文献
933.
黄永年 《宁波大学学报(理工版)》2000,13(4):5-10
分析了连续时间和离散时间的捕食-被捕食模型:Hassel and Rogers的狼与鹿相互作用的模型,发现它们的轨线有一定程度的相似,但从生态意义上讲,离散模型更合适。 相似文献
934.
Yu Quan Xie 《数学学报(英文版)》2008,24(12):1965-1984
In this paper, we study the basic properties of stationary transition probability of Markov processes on a general measurable space (E, δ), such as the continuity, maximum probability, zero point, positive probability set,standardization, and obtain a series of important results such as Continuity Theorem, Representation Theorem, Levy Theorem and so on. These results are very useful for us to study stationary tri-point transition probability on a general measurable space (E, δ). Our main tools such as Egoroff's Theorem, Vitali-Hahn-Saks's Theorem and the theory of atomic set and well- posedness of measure are also very interesting and fashionable. 相似文献
935.
CpTiCl2(OC6H4X‐p) complexes (where X =CH3, Cl, NO2,; Cp = cyclopentadienyl) activated with methylaluminoxane (MAO) were used in syndiotactic polymerization of styrene. High activity and selectivity for all catalysts were found. The styrene conversion and reaction selectivity depend on the catalyst ageing time and temperature, polymerization temperature and the nature of the substituent in the phenoxy ring. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
936.
937.
Summary Stationary phases containing bonded nitrile groups have been synthesized. The effect of the n-alkyl chain length connecting
the nitrile groups to the surface and of the end-capping on the chromatographic properties was studied. The synthesized material
was compared with commercial nitrile phases in the separation of isomeric cresols and xylenols. 相似文献
938.
D. Loss 《Journal of statistical physics》1990,59(3-4):691-723
The quantum-statistical generalization of the well-known classical, linear revised Enskog equation is derived for spatially uniform systems. This new quantum kinetic equation allows the study of equilibrium time correlation functions and their associated transport coefficients of normal quantum fluids where static correlations and degeneracy effects due to particle statistics (both are treated exactly) are important. Furthermore, we derive the quantum-statistical analog of the classical ring operator. These microscopic and systematic derivations are based on a recently developed superoperator formalism (including cluster expansion techniques) that, as a main feature, allows a clear distinction between static and dynamic correlations, which is crucial in the discussion of the Enskog approximation. 相似文献
939.
Teik-Cheng Lim 《Journal of mathematical chemistry》2002,32(3):249-256
Molecular mechanics softwares adopt various set of force field functions. In some cases, reliable data from one set of force field parameters cannot be used in a software that adopts another set of force field. Using mathematical approach, exact relationships between parameters from three bond-bending force fields, namely the (i) harmonic cosine angle, (ii) polynomial series, and (iii) Fourier series, are herein developed. Parameters from these three potential functions are further related to the approximate form, the harmonic angle function, which is valid for small change in chemical bond angle. 相似文献
940.
U. Goginava 《Acta Mathematica Hungarica》2001,93(1-2):59-70
We study the uniform convergence of Walsh-Fourier series of functions on the generalized Wiener class BV (p(n)↑∞)
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献