圆弧形沉积场地对平面瑞利波散射的解析分析

分别采用Biot饱和多孔介质动力学理论和单相介质弹性动力学理论模拟层状沉积谷场地和 周围场地，利用波函数展开法，得出了层状饱和沉积场地对Rayleigh波散射的解析解．进 行参量分析，研究了无量纲入射波频率、层状沉积层排列顺序及相对刚度和厚度等因素对 Rayleigh波散射效应的影响.     

On the stability of multi-layered fluids. Part I: analysis

The linear stability of the Poiseuille flow of multi-layered different fluids, described mathematically by a system of Orr-Somerfeld differential equations, is investigated. A spectral method is used to rewrite this system into a generalized eigenvalue problem, which can be solved with the QZ-algorithm. Special attention is paid to the tractibility of the interfacial conditions of the stability problem. Since we will limit ourselves to a linear stability analysis, the analytical treatment of the interfacial conditions is simplified. Some results related to simple flow configurations are presented. The origin of certain regions of interfacial instability is explained by simple analytical reasoning.     

Scattering of plane SH-waves on cylindrical canyon of arbitrary shape in anisotropic media

The complex function method is used to solve problems of scattering of plane SH-waves on cylindrical canyon topography of arbitrary shape in anisotropic media. This paper gives the complete function series and general expressions with boundary condition to approach the solution of steady state scattering of plane SH-waves on two-dimensional canyon topography in anisotropic media. The problem to be solved can be reduced to a solution of infinite algebraic equation series by using Hermite function and it's orthogonal conditions. The solution can be obtained directly by using computers. Finally, as an example, computational results of scattering of plane SH-waves on a semi-cylindrical canyon topography are presented. The projects sponsored by The Joint Seismological Science Foundation.     

聚焦超声波在层状生物媒质中的二次谐波声场的理论与实验研究

基于Khokhlov-Zabolotkaya-Kuznetsov(KZK)方程，在频域提出了聚焦超声波在层状生物媒质中传播的理论模型，该模型计及生物媒质的吸收、非线性和边界，同时考虑声源的衍射对声传播的影响.数值研究了聚焦超声波的基波和二次谐波在层状生物媒质中的声传播，并与实验结果相比较.研究结果表明，此方法可以有效地描述聚焦超声波在层状生物媒质中的二次谐波声场. 关键词： 聚焦超声波 层状生物媒质 二次谐波     

Macroscopic modeling of urban traffic noise - influence of absorption and vehicle flow distribution

Prediction of noise levels at shielded positions in urban areas is more difficult than on exposed positions. At shielded positions, the predictions method must include multiple reflections, and many sources must be taken into account. Using numerical methods that solve the wave equation is possible, but very computationally heavy. Here two methods have been used, a very simplified ray model and a statistical model. The results show that concentrating the traffic and introducing absorption onto building façades will give lower levels at shielded positions.     

ZrO_2/rGO多层复合薄膜的构筑及其摩擦学性能研究

将层层自组装(LBL)技术与原位还原过程相结合在单晶硅片表面成功构筑了与基底结合牢固、性能优异的氧化锆/还原氧化石墨烯(ZrO2/rGO)多层纳米复合薄膜.试验中,引入了具有强附着性和还原性的物质-多巴胺,使得氧化石墨烯(GO)片的表面锚固和原位还原可以一步完成.另外,ZrO2粒子的表面组装通过简单、温和的溶液沉积过程来实现.结果证明:复合薄膜中rGO和ZrO2的引入以及多层结构的构筑赋予复合薄膜许多优异的性能.在不进行热处理的情况下,所构筑的ZrO2/rGO多层薄膜表现出优异的力学性能(硬度:11.54 GPa)和摩擦学性能(摩擦系数:0.12~0.17),可作为减摩抗磨涂层被用于微/纳机电系统(MEMS/NEMS)的表面保护和其他领域.     

Scattering of SH-waves on triangular hill joined by semi-cylindrical canyon

Scattering of SH-waves on the triangular hill joined by semi-cylindrical canyon in half-space is studied using the method of complex function and moving coordinates. The model being studied is divided into two domains. The wave functions satisfying the required condition at each wedge are constructed in each equation. The equations are solved with Fourier expansion. Numerical results are provided to discuss the influence of scattering of SH-waves.     

任意梯度分布功能梯度涂层平面裂纹分析

提出可以分析任意梯度功能梯度材料的分层模型,并采用该模型研究功能梯度涂层平面裂纹问题.采用Fourier变换和传递矩阵法将该混合边值问题化为奇异积分方程组,通过数值求解获得应力强度因子.考察了分层模型的有效性,以及材料梯度变化形式、结构几何尺寸和材料梯度参数对裂纹应力强度因子的影响,发现结构几何尺寸、材料梯度变化形式、...     

On an extension of the d’Alembert solution to initial–boundary value problems in multi-layered,multi-material domains

This work introduces a method for the exact solution of initial–boundary value problems for linear, one-dimensional conservation laws in multi-layered, multi-material domains. The method is based on the geometry of the solutions of such conservation laws and represents an extension of the d’Alembert solution to initial–boundary value problems in multi-layered, multi-material domains.