压剪复合平板冲击加载技术进展及其应用

自20世纪70年代末发明压剪炮以来, 压剪复合冲击加载实验技术和诊断技术有了长足进展, 应用也日益广泛.由于压剪联合加载波直接反映了材料的动态剪切特性, 对于认识材料的屈服、损伤演化、失效、相变、界面滑移等动态行为和机理, 构筑更全面的本构模型能够提供必要的附加信息.本文主要讨论气炮实验中压剪复合应力波的产生方式, 诊断技术, 以及在压剪复合塑性波和动高压本构模型、聚合物压剪冲击行为、剪切波跟踪法(SWT)和水泥基复合材料的损伤和失效、界面动摩擦行为、冲击相变、动态损伤和断裂等方面的研究与应用进展.      

非均匀水流水域波浪的传播变形

将两个不同的、考虑波流相互作用和能量耗散项的、依赖时间变化的双曲型缓坡方程分别化 为一组等价的控制方程组,具体分析了底摩阻项对相对频率和波数矢的影响,从而选择了合 适的数学模型. 将所选择的缓坡方程化为依赖时间变化的抛物型方程,并用ADI法进 行数值求解,建立了缓变水深水域非均匀水流中波浪传播的数值模拟模型. 通过和波流共线 的解析解的比较,说明数值解和解析解相一致. 结合Arthur(1950)水流这一经典算例,定 量地讨论了考虑联合折射-绕射作用后的波数和仅考虑折射作用的波数的差别及其对波高分 布的影响. 在基本同样的条件下, 本文的数值解与他人的计算结果一致.     

光纤组束激光对可见光硅CCD的有效干扰距离分析

为了分析光纤组束激光对可见光硅CCD的有效干扰距离,对组束激光功率及可见光CCD的饱和阈值进行了分析。在弱湍流和热晕条件下对组束激光的远场功率密度进行了数值计算,计算结果表明该条件下组束激光对可见光CCD的有效干扰距离达到10km左右,组束激光是未来实施光电干扰的又一有效途径。     

基于独立性和时效性管理的弹性力学经典解答的数据库构筑1)

在前期交互式操作和可视化教学方法的探讨和实践基础上,通过Visual C++和MATLAB联合编程,构筑了基于独立性和时效性管理的弹性力学经典解答数据库。数据库采用模块化设计和子程序并行计算方法,建立了问题描述模块、参数输入模块、可视化结果输出模块和结果调用模块,实现了调用模块对数据的独立性调用和可视化模块的动态调整。数据库各个计算子程序采用多线程并行计算,以及显示模块的快速准确输出结果,保证了交互式操作的时效性,达到了对弹性力学经典解答的形象、生动、有 色彩的教学目的。     

Layered crystals of apo‐ and holoferritin grown by alternating crystallization

We report on the use of alternating crystallization for deposition of layers of different (though closely related) proteins in a single crystal. Investigations were carried out with the unique protein couple consisting of two forms of ferritin, apoferritin and holoferritin from horse spleen, which, despite being of quite different molecular masses, still possess identical organic shells. Crystals of both proteins were used as substrates for subsequent contiguous growth of the partner protein in perfect alignment. We observed continuous growth of combined (onion‐like) single crystals; artificial structures of biological macromolecules can be designed in this way. The homoepitaxial layered growth shows in an unambiguous way that protein crystallization depends only on the surface protein conformation and amino‐acid composition, but not on the internal molecule structure. The limitations of protein crystal growth for designing layered structures of biological macromolecules were revealed by growing of heterogeneous protein crystals onto pre‐existing protein crystalline substrates. Tetragonal crystals of hen egg‐white lysozyme were grown onto cubic apoferritin crystals used as substrates. It was observed that the lysozyme crystals were not lattice‐matched to the ‘host’ apoferritin crystals; this led to mere aggregates of different crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Normalized ground state for the Sobolev critical Schrödinger equation involving Hardy term with combined nonlinearities

In this paper, we study the existence and properties of normalized solutions for the following Sobolev critical Schrödinger equation involving Hardy term: $$-\mathrm{\Delta }u-\frac{\mu }{{|x|}^2}u=\lambda u+{|u|}^{2^{\ast }-2}u+\nu {|u|}^{p-2}u\text{in}{\mathbb{R}}^N,N\ge 3,$$ with prescribed mass $${\int }_{{\mathbb{R}}^N}{u}^2=a^2,$$ where 2* is the Sobolev critical exponent. For a L²-subcritical, L²-critical, or L²-supercritical perturbation ${\nu |u|}^{p-2}u$, we prove several existence results of normalized ground state when $\nu \ge 0$ and non-existence results when $\nu \le 0$. Furthermore, we also consider the asymptotic behavior of the normalized solutions u as $\mu \to 0$ or $\nu \to 0$.