弹性波

Based on the wave equations established in general coordinate system for orthorhombic anisotropy media, this paper di...

在建立一般观测坐标系下正交各向异性介质波动方程的基础上，着重讨论了相应的伪谱法波场数值计算的稳定性条件，进而用伪谱法实现了正交各向异性介质弹性波场的正演模拟，获得了很好的模拟效果

Estimated V〓、V〓 data from Kuandian xenoliths, combining with the observed V〓、V〓 data, imply that the composition of the uppermost mantle lithosphere within 40-50km beneath Kuandian may be composed of 50％ spinel peridotite and 50% garnet pyroxenite.

计算了不同产地深源包体的弹性波速V〓、V〓值，将宽甸地区包体波速计算值与实测地震波速资料进行对比，确定了宽甸地区上地幔岩石圈顶部的物质组成大致为50％的尖晶石橄榄岩+50％的石榴石辉石岩。

Based on up_ and down_going wave decomposition and elastic wave power reciprocity theorem, this paper derives, in the lateral velocity varying case, linear prediction operators expression and the generalized spectral factorization equation for reflection dataset.

本文基于上下行波分解及弹性波互易定理，导出横向变速介质条件下线性预测算子的表达式和反射数据的广义谱分解方程。

There are two kinds of elastic waves in solids a compressional wave and a transverse wave.

在固体中有两类弹性波，一类是压缩波，另一类是横波。

And the special phenomena such as the S wave splitting, the blind points of the S wave splitting and wavefront triplication are dearly observed.

另外，三维双相各向异性介质中弹性波场的快纵波和快横波的耦合关系、波的类型、能量分布和相位等都是在三维空间中变化的。

The results show that there exist the fast P wave (qP1), fast S wave (qS1), slow S wave(qS2) and slow P wave(qP2) in 3-D dual-phase anisotropic media during the propagation of elastic wave. And the special phenomena such as the S wave splitting, the blind paints of the S wave splitting and wavefront triplication are clearly observed.

结果表明，弹性波在三维双相各向异性介质中传播时存在快纵波qP1、快横波qS1、慢横波qS2和慢纵波qP2，并清楚地观测到了横波分裂、横波分裂盲点、波面三分叉等特殊现象。

The motivation for these studies is to better understand the Anderson localization of sound and vibrations in composite media, as well as their numerous engineering applications such as elastic/acoustic filters, vibrationless environments for high-precision mechanical systems or the design of new transducers.

而这些研究也具有实际的应用价值，例如，我们可以设计出一种新的弹性波的滤波器、波导器，以及给高精密的仪器设备提供一个无振动的环境等等。

We detailedly analyse the low-frequency radiative energies of the elastic waves which are generated by different axially symmetric sources in fluid — filled boreholes, and formulize the energies of tube,compressional and shear waves.

本文详细研究了充流体井中由不同类型轴对称震源激发的弹性波的低频辐射能量，导出了管波、纵波和横波能量的解析解表达式。

Based on anisotropic elastic wave equation staggering grid high-order finite-difference numerical simulation, the wave field response characteristics of vertical fracture medium with different densities and infillings were studied.

利用各向异性弹性波方程交错网格高阶有限差分数值模拟方法，开展了不同密度和不同充填物的垂直裂隙介质的波场响应特征研究。

In the process of building and using the mass concrete structures, because of the effect of out-side condition and themselves, some faults will form in the structure, these faults will effect the bearing capability and endurance Using nondestructive testing method to test the concrete"s quality and diagnose its healthy, which has the significant sense in assessing the safety stability and research of the administering diseasesThis dissertation mostly researched the testing methods in the mass concrete structure, discussed the principles, methods, features, sphere of application of the ultrasonic testing in the mass concrete structure with faults, used dynamic FEM to simulate the testing process, discussed when the concrete structure with cracks is under the effect of the pulse, how the elastic waves propagate and what are their changing feature, Researched the principles of the first-arriving waves" phase when the cracks" depths are not same, obtained the relation between the inversion point and the cracks" depth, which has the direction sense in the application of projects,The second part of this dissertation is CT , which used the ultrasonic wave running through the tested-substance to get arriving-time of the ultrasonic wave, then inverse the image This dissertation drawed one CT program which can well present the different little cells ultrasonic wave velocity profiles of the substance, thereby to diagnose the quality of the part of the tested-substance, CT has the better using foreground..

在混凝土结构的施工及使用过程中，由于受其自身及外界各种因素的影响，常常会产生一些缺陷，对结构物的承载能力和耐久性造成严重影响，采用无损检测技术进行质量检测和健康诊断，这对混凝土结构开展安全、稳定性评估以及病害隐患治理研究具有重要意义。本论文主要针对大体积混凝土结构缺陷的检测方法展开研究工作，重点讨论了超声波法检测混凝土结构裂缝的基本原理和方法及其特点、适用范围，运用动力有限元数值模拟其检测过程，探讨了有裂缝缺陷的混凝土结构在脉冲荷载作用下弹性波的传播及其变化特征，研究了不同裂缝深度下首波相位变化规律，得出了反转临界点与裂缝深度之间的关系，这对实际工程应用具有指导意义。声波CT是一种新的无损检测技术，它是利用声波穿透被检测体获取声波接收时间，来进行计算机反演成像的技术。本文利用直射线法编制了层析成像程序，能较好地呈现被检测物体各微小单元的声波速度分布图像，从而对检测体的质量状况作出诊断评估，具有较好的应用发展前景。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。