共轭聚合物中均匀无序对极化子输运动力学的影响

基于扩展的Su-Schrieffer-Heeger紧束缚模型和非绝热动力学方法, 研究了共轭聚合物材料中均匀无序效应对极化子输运动力学的影响. 研究发现: 极化子的动力学输运过程由外加电场和均匀无序效应共同决定; 在大部分电场范围下, 均匀无序效应对极化子输运的影响不太明显, 几乎可以忽略; 但在弱电场下, 均匀无序效应不利于极化子输运. 与高斯型无序效应下极化子的输运过程相比, 具有均匀无序的薄膜形貌更有利于极化子输运.     

基于简单透镜列阵的可调焦激光均匀辐照光学系统研究

本文对基于简单透镜列阵的大口径激光均匀辐照光学系统的调焦能力进行了研究, 结果表明, 改变透镜列阵与靶镜之间的距离即可方便地改变靶面上光斑的大小. 文中详细分析了相关参数对调焦能力的影响, 并在此基础上设计出一个实用的光学系统. 用数值方法模拟了激光束通过光学系统后的传输, 发现尺寸不同的靶面光斑具有基本一致的强度结构特征. 定量地分析了光斑内部散斑间隔、调制对比度、顶部不均匀度及能量集中度等描述光斑均匀辐照质量的指标, 并研究了它们随靶面离焦量的变化关系.     

光栅投影相位法系统模型及标定方法

本文针对传统投影光栅相位法的光学三角法模型进行了改进,采用直入射光路并配合使用一种简便易行的标定方法,只需使用相移公式求取相位差,而不会引入与系统几何位置关系有关的量,简化了求取高度矩阵的要求。实验结果表明,新系统模型精度良好,测量误差为0.107 mm。采用该模型和标定方法可以克服传统方法系统模型的局限性,最大限度减少误差源并提高抗干扰性。     

Plane strain wave in an isotropic layer of a viscoelastic material

The velocity and the rate of decay of a strain wave in a layer of a viscoelastic material rigidly fixed on a solid foundation are determined. The wave structure (ratio of the longitudinal to the transverse displacement) and the profiles of these displacements are analyzed. Attenuation of waves in the first mode is found to be more significant than that in an infinite space. The most intense decay is observed at resonance frequencies. A strong effect of compressibility of the medium on wave parameters is revealed. Conditions at which such a system operates as a waveguide are found. For a loss tangent higher than 0.13 (for an incompressible medium), the character of the dispersion dependence is observed to change drastically: the wave velocity decreases with decreasing frequency. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 3, pp. 104–111, May–June, 2006.     

A UNIFORMLY DIFFERENCE SCHEME OF SINGULAR PERTURBATION PROBLEM FOR A SEMILINEAR ORDINARY DIFFERENTIAL EQUATION WITH MIXED BOUNDARY VALUE CONDITION

ＡＵＮＩＦＯＲＭＬＹＤＩＦＦＥＲＥＮＣＥＳＣＨＥＭＥＯＦＳＩＮＧＵＬＡＲＰＥＲＴＵＲＢＡＴＩＯＮＰＲＯＢＬＥＭＦＯＲＡＳＥＭＩＬＩＮＥＡＲＯＲＤＩＮＡＲＹＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＷＩＴＨＭＩＸＥＤＢＯＵＮＤＡＲＹＶＡＬＵＥＣＯＮＤＩＴ...     

Turbulence Energy Distribution in the Stokes Layer

Using the method of matched asymptotic expansions, an analytical solution of the balance equation for turbulence energy is constructed for a shallow basin (sea) in which the fluid depth does not exceed the Stokes layer thickness. In this case, a gradient-viscous balance is established with the turbulent viscosity being balanced mainly by the pressure gradient. It is shown that nonlinear boundary layers attributable to turbulence energy diffusion are formed near the bottom and the free surface (or ice). In the neighborhood of the point of maximum flow velocity (if this maximum is attained inside the flow), a nonlinear internal boundary layer also develops. Outside these layers, the turbulence energy generation is in the first approximation balanced by the energy dissipation. Asymptotic solutions for the boundary layers are constructed.     

PLASTIC BUCKLING OF STIFFENED TORISPHERICAL SHELL

ＰＬＡＳＴＩＣＢＵＣＫＬＩＮＧＯＦＳＴＩＦＦＥＮＥＤＴＯＲＩＳＰＨＥＲＩＣＡＬＳＨＥＬＬＨａｏＧａｎｇ（郝刚）ＺｅｎｇＧｕａｎｇｗｕ（曾广武）ＨａｏＱｉａｎｇ（郝强）（ＲｅｃｅｉｖｅｄＤｅｃ．３０，１９９４．ＣｏｍｍｕｎｉｃａｔｅｄｂｙＰａｎＬｉｚｈ...     

化学跑合剂对跑合效果的影响

在ＢＪ５２Ａ胶合试验机、ＪＰ－ＢＤ１５００型接触疲劳试验机和ＣＬ－１００齿轮试验机上考察了化学跑合剂的作用，并就其机理进行了探讨。结果表明：采用化学跑合剂跑合后，表面粗糙度明显降低；表面接触面积增大，可以实现１次满载快速跑合；与采用含磨料的跑合方法比较，化学跑合剂可以明显提高表面接触精度，减少裂纹源的发生和发展，使表面承载能力明显提高。当齿轮加工精度较低或高速、重载齿轮的硬齿面精加工存在困难时，可