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981.
Marcin Buchowiecki 《International journal of quantum chemistry》2012,112(4):1107-1113
Rate constant ratios k(T)/k(1,500K) for two symmetrical reactions H? + H2 → H2 + H? and H+ + H2 → H2 + H+ are reported. Direct method based on quantum instanton approximation for evaluation of the temperature dependence of the quantum‐mechanical reaction rate constant is used. Implementation of the theory involves thermodynamic integration and path integral Monte Carlo method. Results of anionic case shows resemblance to neutral case, whereas cationic case is significantly different and below 1,000K rate constant shows strong deviation form linearity of Arrhenius plot due to high activation barrier. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
982.
983.
Mai Duc Thanh 《Communications in Nonlinear Science & Numerical Simulation》2012,17(1):195-211
We consider a two-fluid model of two-phase compressible flows. First, we derive several forms of the model and of the equations of state. The governing equations in all the forms contain source terms representing the exchanges of momentum and energy between the two phases. These source terms cause unstability for standard numerical schemes. Using the above forms of equations of state, we construct a stable numerical approximation for this two-fluid model. That only the source terms cause the oscillations suggests us to minimize the effects of source terms by reducing their amount. By an algebraic operator, we transform the system to a new one which contains only one source term. Then, we discretize the source term by making use of stationary solutions. We also present many numerical tests to show that while standard numerical schemes give oscillations, our scheme is stable and numerically convergent. 相似文献
984.
Hui Wang Tie-cheng Xia 《Communications in Nonlinear Science & Numerical Simulation》2012,17(2):566-572
Based on a well known super Lie algebra, a super integrable system is presented. Then, the super G-J hierarchy with self-consistent sources are obtained. Furthermore, we establish the infinitely many conservation laws for the integrable super G-J hierarchy. The methods derived by us can be generalized to other nonlinear equations hierarchies with self-consistent sources. 相似文献
985.
Wentian Li 《Complexity》2012,18(1):44-50
We examine the complete dataset of baby name popularity collected by U.S. Social Security Administration for the last 131 years (1880–2010). The ranked baby name popularity can be fitted empirically by a piecewise function consisting of Beta function for the high‐ranking names and power‐law function for low‐ranking names, but not power‐law (Zipf's law) or Beta function by itself. © 2012 Wiley Periodicals, Inc. Complexity, 2012 相似文献
986.
研究了多元球体上的积分中值定理的中间点的渐近性质,证明了当球体半径趋于0时,中间点近似落在过球体中心的切平面上. 相似文献
987.
LiXin Zhang 《中国科学 数学(英文版)》2012,55(11):2379-2404
The Friedman’s urn model is a popular urn model which is widely used in many disciplines.In particular,it is extensively used in treatment allocation schemes in clinical trials.Its asymptotic properties have been studied by many researchers.In literature,it is usually assumed that the expected number of balls added at each stage is a constant in despite of what type of balls are selected,that is,the updating of the urn is assumed to be balanced.When it is not,the asymptotic property of the Friedman’s urn model is stated in the book of Hu and Rosenberger(2006) as one of open problems in the area of adaptive designs.In this paper,we show that both the urn composition process and the allocation proportion process can be approximated by a multi-dimensional Gaussian process almost surely for a general multi-color Friedman type urn model with heterogeneous and unbalanced updating.The Gaussian process is a solution of a stochastic differential equation.As an application,we obtain the asymptotic properties including the asymptotic normality and the exact law of the iterated logarithm. 相似文献
988.
Adaptive synchronization of chaos in permanent magnet synchronous motors based on passivity theory 下载免费PDF全文
An adaptive synchronization control method is proposed for chaotic permanent magnet synchronous motors based on the property of a passive system.We prove that the controller makes the synchronization error system between the driving and the response systems not only passive but also asymptotically stable.The simulation results show that the proposed method is effective and robust against uncertainties in the systemic parameters. 相似文献
989.
Zafar Iqbal Muhammad Nawaz Naeem Nazra Sultana Shahid Hussain Arshad Abdul Ghafar Shah 《应用数学和力学(英文版)》2009,30(11):1393-1404
The vibration characteristics of a functionally graded material circular cylindrical shell filled with fluid are examined with a wave propagation approach. The shell is filled with an incompressible non-viscous fluid. Axial modal dependence is approximated by exponential functions. A theoretical study of shell vibration frequencies is analyzed for simply supported-simply supported, clamped-simply supported, and clamped-clamped boundary conditions with the fluid effect. The validity and the accuracy of the present method are confirmed by comparing the present results with those available in the literature. Good agreement is observed between the two sets of results. 相似文献
990.