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71.
Positive solutions for a p-Laplacian type system of impulsive fractional boundary value problem 下载免费PDF全文
In this paper, the aim is to discuss a class of p-Laplacian type fractional Dirichlet"s boundary value problem involving impulsive impacts. Based on the approaches of variational method and the properties of fractional derivatives on the reflexive Banach spaces, the existence results of positive solutions for our equations are established. Two examples are given at the end of each main result. 相似文献
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M. Diehl D. An P. Shanthraj S. Zaefferer F. Roters D. Raabe 《Physical Mesomechanics》2017,20(3):311-323
Dual phase steels are advanced high strength alloys typically used for structural parts and reinforcements in car bodies. Their good combination of strength and ductility and their lean composition render them an economically competitive option for realizing multiple lightweight design options in automotive engineering. The mechanical response of dual phase steels is the result of the strain and stress partitioning among the ferritic and martensitic phases and the individual crystallographic grains and subgrains of these phases. Therefore, understanding how these microstructural features influence the global and local mechanical properties is of utmost importance for the design of improved dual phase steel grades. While multiple corresponding simulation studies have been dedicated to the investigation of dual phase steel micromechanics, numerical tools and experiment techniques for characterizing and simulating real 3D microstructures of such complex materials have been emerged only recently. Here we present a crystal plasticity simulation study based on a 3D dual phase microstructure which is obtained by EBSD tomography, also referred to as 3D EBSD (EBSD—electron backscatter diffraction). In the present case we utilized a 3D EBSD serial sectioning approach based on mechanical polishing. Moreover, sections of the 3D microstructure are used as 2D models to study the effect of this simplification on the stress and strain distribution. The simulations are conducted using a phenomenological crystal plasticity model and a spectral method approach implemented in the Düsseldorf Advanced Material Simulation Kit (DAMASK). 相似文献
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从理论和实验上研究了利用光注入半导体激光器对高重复速率光脉冲产生的周期振荡和时钟分频现象.结果表明,光注入半导体激光器引起的二倍周期振荡是使注入脉冲重复频率分频的直接原因.通过耦合速率方程,数值模拟了半导体激光器在外光注入时输出光的时间序列和功率谱,并且分析了激光腔内各种周期振荡的特征.研究表明,当注入光使半导体激光器出现稳定的二倍周期振荡,且注入光的重复频率为此振荡频率的二倍时,时钟分频即可产生实验中,采用重复频率为6.32GHz的光脉冲注入Fabry-Perot激光器,实现了3.16GHz时钟分频信号
关键词:
周期振荡
时钟分频
光谱侧带
光注入 相似文献
77.
AN WeiGuang ZHAO WeiTao & AN Hai Department of Aerospace Engineering Harbin Engineering University Harbin China College of Aeronautics Astronautics Shenyang Institute of Aeronautical Engineering Shenyang China 《中国科学G辑(英文版)》2007,50(3):357-369
Multi-failures are possible to appear in the process of using the structural system, such as dead load failure, fatigue failure and stiffness failure. The expression of residual resistance is given based on the impact of random crack propagation in- duced by the fatigue load on the critical limit stress and section modulus in this paper. The failure modes of every element of the structural system are analyzed under dead and fatigue loads, and the influence of the correlation of failure modes on reliability of the element is considered. Failure mechanism and the correlation of failure modes under dead and fatigue loads are discussed, and the method of reli- ability analysis considering static strength, fatigue and stiffness is given. A nu- merical example is analyzed, which indicates that the failure probability is different for different use life and the influence of dead and fatigue loads on reliability of the structural system is different as well. This method of reliability analysis, in the pa- per, is better than the method only considering a single factor (or static strength, or fatigue, or stiffness, etc.) in the case of practical engineering. 相似文献
78.
Existence and Multiplicity of Positive Solutions for Fractional Differential Equation with Parameter 下载免费PDF全文
In this paper, by using the ?xed point theorem for a cone map, we study the existence and multiplicity of positive solutions for a class of fractional di?erential equation with parameter. 相似文献
79.
The asymptotics of the necessary sample size is considered in testing close hypotheses when the error probabilities vanish.
Proceedings of the XVII Seminar on Stability Problems for Stochastic Models, Kazan, Russia, 1995, Part III. 相似文献
80.
用波长为623.8nm的He-Ne激光作信号光和一束泵浦光,用波长为488.0nm的Ar+激光作另一束泵浦光,在Eu:Fe:LiNbO3晶体中实现了非简并四波混频,获得了波长为488.0nm的变频相位共轭光,同时还产生了波长为632.8nm的同频相位共扼光。本文对上述实验结果进行了定性分析。 相似文献