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991.
992.
XIEWen-Fang ZHUWu 《理论物理通讯》2003,40(1):113-116
The energy spectra of low-lying states of an exciton in a single and a vertically coupled quantum dots are studied under the influence of a perpendicularly applied magnetic field. Calculations are made by using the method of numerical diagonalization of the Hamiltonian within the effective-mass approximation. We also calculated the binding energy of the ground and the excited states of an exciton in a single quantum dot and that in a vertically coupled quantum dot as a function of the dot radius for different vaJues of the distance and the magnetic field strength. 相似文献
993.
994.
Tristan Rivière 《Letters in Mathematical Physics》1998,45(3):229-238
We introduce a formulation of the Skyrme problem using differential forms. By means of this formulation, we prove first that the homothetic map between the standard three-sphere of radius R, S3
r R4, and S3
1 is the unique minimizer, modulo isometries, of the Skyrme energy in its homotopy class, for any R less than some critical value R0 (3/2, 2]. We then establish a stability result for this Skyrme-form problem from which we can recover the result of M. Loss and N. S. Manton which states that this homothetic map is stable only up to R = 2. 相似文献
995.
996.
997.
In this paper, chaotic behaviours in the fractional-order Liu system
are studied. Based on the approximation theory of fractional-order
operator, circuits are designed to simulate the fractional- order
Liu system with $q=0.1-0.9$ in a step of 0.1, and an experiment has
demonstrated the 2.7-order Liu system. The simulation results prove
that the chaos exists indeed in the fractional-order Liu system with
an order as low as 0.3. The experimental results prove that the
fractional-order chaotic system can be realized by using hardware
devices, which lays the foundation for its practical applications. 相似文献
998.
利用高温高压技术,在不同的压力和温度(-4.5GPa,-800℃)下将LaNi5基快淬合金粉直接压制成了块状纳米晶合金。X射线衍射分析表明,高压使其晶粒内部发生了明显的压致晶粒碎化,其平均晶粒尺寸在4.5GPa下从75.5nm降至24.6nm。利用正电子湮灭技术研究了这种晶粒碎化效应对纳米合金内部缺陷结构的影响。测试结果表明,在高温高压的作用下,由于界面上原子的迁移和弛豫加剧,导致晶界上尺寸较大的微孔隙缺陷逐渐转化为尺寸较小的自由体积缺陷,使得纳米合金的致密度逐渐增强,显微硬度逐渐升高,从而在高温高压下得到致密的块状纳米合金材料。 相似文献
999.
Sliced Latin hypercube designs are very useful for running a computer model in batches, ensembles of multiple computer models, computer experiments with qualitative and quantitative factors, cross-validation and data pooling. However, the presence of highly correlated columns makes the data analysis intractable. In this paper, a construction method for sliced (nearly) orthogonal Latin hypercube designs is developed. The resulting designs have flexible sizes and most are new. With the orthogonality or near orthogonality being guaranteed, the space-filling property of the resulting designs is also improved. Examples are provided for illustrating the proposed method. 相似文献
1000.
《Communications in Nonlinear Science & Numerical Simulation》2014,19(6):2005-2011
A new 4-D fractional-order chaotic system without equilibrium point is proposed in this paper. There is no chaotic behavior for its corresponding integer-order system. By computer simulations, we find complex dynamical behaviors in this system, and obtain that the lowest order for exhibiting a chaotic attractor is 3.2. We also design an electronic circuit to realize this 4-D fractional-order chaotic system and present some experiment results. 相似文献