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51.
Sameen Ahmed Khan 《Optik》2006,117(10):481-488
52.
In film growth on quasicrystalline surfaces, the epitaxy-imposed ordering cannot compete with the stable bulk phases of thick films due to absence of translational order in the structure of the substrate. Energetically, this renders the formation of crystalline domains in the native structure of the film material more favorable, while their global orientation is prescribed by the quasicrystalline order. We present experimental results on the dissociative chemisorption of oxygen at the decagonal surface of Al70Co15Ni15 as well as molecular-dynamics simulations of the diffusion of adatoms on the surface of the partially covered substrate. 相似文献
53.
In the materials of micro-structured, the propagation of wave modeling should take into account the scale of various microstructures. The different kinds solitary wave solutions of strain wave dynamical model are derived via utilizing exp\((-\phi(\xi))\)-expansion and extended simple equation methods. This dynamical equation plays a key role in engineering and mathematical physics. Solutions obtained in this work include periodic solitary waves, Kink and anti-Kink solitary waves, bell-shaped solutions, solitons, and rational solutions. These exact solutions help researchers for knowing the physical phenomena of this wave equation. The stability of this dynamical model is examined via standard linear stability analysis, which authenticate that the model is stable and their solutions are exact. Graphs are depicted for knowing the movements of some solutions. The results show that the current methods, by the assist of symbolic calculation, give an effectual and direct mathematical tools for resolving the nonlinear problems in applied sciences. 相似文献
54.
F.S. Amaral 《Physica A》2007,385(1):137-147
We investigate arbitrary stochastic partial differential equations subject to translation invariant and temporally white noise correlations from a nonperturbative framework. The method that we expose first casts the stochastic equations into a functional integral form, then it makes use of the Gaussian effective potential approach, which is an useful tool for describing symmetry breaking. We apply this method to the Kardar-Parisi-Zhang equation and find that the system exhibits spontaneous symmetry breaking in and (3+1) Euclidean dimensions, providing insight into the evolution of the system configuration due to the presence of noise correlations. A simple and systematic approach to the renormalization, without explicit regularization, is employed. 相似文献
55.
56.
In this paper, the spin-dependent electron transport is studied in detail in a magnetic nanostructure with a δ-function potential. It is shown that the large spin-polarization can be achieved in such a device, and the degree of the spin-polarization strongly depends on the height of the δ-function potential. It is also shown that the conductance-polarization apparently has the bigger oscillatory magnitudes with the height of δ-function potential increasing. These interesting features will be more helpful for developing new types of devices. 相似文献
57.
山西白皮松林的初步研究 总被引:2,自引:0,他引:2
利用样方法抽样调查山西省太岳山、吕梁山、太行山的白皮松,结果是在山西南部低山丘陵区用该树种营造水土保持林,具有重要的科学价值和生态学意义。 相似文献
58.
Manabu Iwasa 《Journal of multivariate analysis》1996,59(2):249-271
A variety of convolution inequalities have been obtained since Anderson's theorem. ?In this paper, we extend a convolution theorem forG-monotone functions by weakening the symmetry condition ofG-monotone functions. Our inequalities are described in terms of several orderings obtained from a cone. It is noteworthy that the orderings detect differences in directions. A special case of the orderings induces a majorization-like relation on spheres. Applying our inequality, Bartholomew's conjectures, which concern directions yielding the maximum power and the minimum power of likelihood ratio tests for order-restricted alternatives, are partly settled. 相似文献
59.
福州船政局系湘系集团首领左宗棠所创办的大型军工企业,对于近代中国轮船制造业的进步和海防建设具有重要意义。淮系集团及其首领李鸿章,毅然摒弃派系畛域,与湘系官员携手合作,共同促进了福州船政局,乃至整个近代中国轮船制造业和海防建设的发展。 相似文献
60.
We consider a stochastic serial inventory system with a given fixed batch size per stage and linear inventory holding and penalty costs. For this system, echelon stock (R,nQ) policies are known to be optimal. On the basis of new average costs formulas, we obtain newsvendor equations for the optimal reorder levels. 相似文献