横波

In this paper, we research the imaging problems beneath volcanic area. We sort common asymptotic conversion point gathers and perform velocity analysis to establish the initial velocity which will be used in PSTM. By scanning migration velocity and V p/ V s, we get the optimum migration velocity and

本文针对火山岩地震屏蔽层的转换波成像问题，通过对转换波共近似转换点道集进行速度分析，建立了转换波叠前时间偏移的初始速度场，通过速度扫描和纵、横波速度比值扫描确定最佳的偏移速度场和纵、横波速度比值，实现了在火山岩高速层覆盖区域的转换波偏移成像。

The transverse wave disturbance along tangential base flow of circular vortex is discussed By using numerical method we study this instability of baroclinic flow which is mesoscale inertia wave instability on the cylindrical coordinate The influence of stratification stability N 2 , Coriolis parameter f 0 , the vertical shear of tangential wind z of the ambinent atmosphere and the latent heat on the growth rate of instability is studied From the above analysis and calculation, we can learn that there are Eady mode and mesoscale mode of transverse wave instability in circular vortex as well Furthermore we also learn that distribution character of mesoscale mode disturbance field of transverse wave instability, anomalistic "cats eye" structure of lower level and the character of the slowly spreading disturbance converges at low level and the quickly spreading disturbance converges at high level

作者中文名：李红金；陆汉城；宋晓亮；李鲲摘要：讨论涡旋大气中，存在沿切向基流传播的横波型扰动，并采用数值方法讨论了柱坐标系下圆形涡旋系统斜压气流中这类扰动的不稳定，这是一类中尺度的重力惯性波的不稳定。研究了涡旋环境大气的层结稳定度参数N2、切向风垂直切变Vz、凝结潜热、涡旋特性及科里奥利参数f0对不稳定增长率的影响。圆形涡旋中同样存在横波不稳定的Eady模态和中尺度模态，得到了中尺度模态的扰动场分布特征：流场的不规则"猫眼"结构及慢速传播的扰动均集中在低层，而快速传播的扰动均集中在高层的扰动特征。

The extracted P-wave is reverse-time extrapolated and imaged with a P-velocity model using a finite difference solution of the scalar wave equation, the extracted S-wave is reverse-time extrapolated and imaged similarly, but with an S-velocity model, and converted S-wave data requires a polarity correction prior to migration to ensure constructive interference between data from adjacent source.

在模型中，每个网格点的纵、横波成像时间，为震源到该网格点的纵波初至时间。利用纵波速度模型和声波传播方程的有限差分解，对反射纵波进行逆时延拓和成像，利用横波速度模型和声波传播方程的有限差分解，对转换横波进行逆时延拓和成像，并在偏移前进行极性校正。

Through S-wave polarization scanning mode of ultrasonic impulse testing, rock samples with three different properties are measured to evaluate the variation of S-wave velocity in three perpendicular coordinates. By analyzing S-wave splitting of three directions and polarization of the maximum or minimum speed S-wave amplitudes, we think that the velocity orthotropy and fracture orientation observed in the grain sandstones and crack marble samples can be estimated in terms of the polarization and velocity of S-wave. Also, perpendicularity characteristics on the two types of rocks can attribute to the bedding and structure of rocks (directional grains or crystallize).

在实验室通过选择了三种不同岩性的岩石，采用超声脉冲测试方法中的横波偏振扫描方式，观测了岩石样品三个坐标方向上的横波速度变化，通过分析三个传播方向上出现横波分裂的差异，以及出现最大或最小快慢横波振幅的偏振方向发现，可从横波偏振方向和速度值判断出纹理砂岩和裂隙大理岩样品存在不同程度的速度正交各向异性和裂隙方向等特征，认为这两种岩石的正交特性的原因是岩石的层理或裂隙与岩石本身的结构构成的。

Angular spectral is spectral value map formed by estimating semblable coefficients of fast and slow shear wave or the variation of amplitude ratio of fast and slow shear wave with times and angles at a specified space point based on semblable theory of fast and slow shear wave, the angle value of this space point at a given time can be got by picking the maximum of angular spectral; the study reveals that fast and slow shear wave with different polarization direction should be separated using different rotation formula, eight formulas of separating fast and slow shear wave using clockwise rotation and counterclockwise rotation have been derived, and gained energy assignment rule and phase coincidence rule, in real data estimation, the rotation formula used for separating fast and slow shear wave can be uniquely determined on the two discriminating rules. On the basis of semblable theory of fast and slow shear wave, the delay time corresponding to the maximum of semblable coefficients at a specified point in a given time window is the delay time of fast and slow shear wave, delay time section of fast and slow shear wave can be got by moving space point and smoothing time window. The vertical variation values of delay time of fast and slow shear wave reflect the effect degree of vertical fractured reservoir on fast and slow shear wave which is defined as anisotropic coefficient, and section map of anisotropic coefficient can be obtained.

角度谱就是利用快慢横波的相似性原理，在某一空间点求出快慢横波的相似系数或快慢横波的振幅比值随着时间和角度的变化而形成的谱值图，拾取其极大值就得到该空间点某一时间的角度值；在研究中发现分离不同偏振方向的快慢横波应该采用不同的旋转公式，推导出了利用顺时针旋转和逆时针旋转分离快慢横波的八个公式，并给出了能量分配准则和相位一致性准则两个判别准则，在实际计算中利用这两个判别准则能唯一地确定分离快慢横波的旋转公式；根据快慢横波的相似性原理，在某一给定点和给定时窗内最大相似系数对应的延迟时间就是快慢横波的延迟时间，随着空间点的移动和时窗的滑动就可以得到快慢横波延迟时间的剖面图；快慢横波延迟时间与慢横波传播时间的比值定义为裂缝密度，并求出了裂缝密度剖面图；快慢横波延迟时间纵向上的变化值的大小反映了纵向上裂隙层对快慢横波影响的大小，定义为各向异性系数，并求出了各向异性系数的剖面图。

The results show that signal-to-noise ratio and characteristics of the measured waves are good, and that slowness curves of fast and slow waves, anisotropy, and fast and slow shear-wave azimuth match well with each other.

结果表明，该仪器测得的波形信噪比高，波形特征清楚正确，资料处理结果中的快、慢横波慢度与各自的横波波形、各向异性及快、慢横波面方位角等都有良好的对应关系。

With oblique incidence transversal wave, defect mode of transversal wave decreases with increase of incident angle.

得到当横波斜入射时，透射波中横波的缺陷模随着入射角的增大而减弱，横波向纵波的转型随着入射角的增大而增强。

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。

Simulation results show that both the longitudinal and transverse wave are included in the reflected waves,the reflection coefficient of longitudinal wave augments with the increase of the incident angle,and the reflection coefficient of transverse wave augments first and then minishes,the transverse wave disappears when the incident angl.

主要研究了声波从粘弹性介质向流体介质斜入射情况下的声反射特性，分析表明：反射声波中有横波和纵波同时存在，纵波声压反射系数随入射角度的增大逐渐增大，横波的声压反射系数随入射角度的增加先增大后减小，在垂直入射时只有纵波，而没有横波存在。

Evidence suggests that 1 under more stable stratification, the basic flow, if moving faster at low and high levels (particularly in the presence of jets there), allows a resulting meso-β unsteady wave to propagate eastward with respect to basic flow and even at greater velocity compared with it; 2 vertical windspeed shear of basic flow causes instabilities of the TWT perturbation; 3 considering the second derivative of basic-flow wind with respect to z (denoted by zz≠ 0 which is simply given as β* hereafter) the expression for the phase velocity of vortex Rossby wave is obtained, which is unidirectional in propagation with respect to basic flow; 4 VRoW has its physical origin from β*, i.e., from z-varying heterogeneities of y-direction averaged vorticity of the basic flow field; 5 VRoW phase velocity is associated with zonal wave number k, its energy is dispersive and the group velocity exists in the x direction; 6 when windspeed meets the condition of β*, TWT disturbance instability may be that of mixed VRoW and gravity wave; 7 if basic flow is subject to linear shear but does not meet the condition of β*, the TWT instability is that of inertia-gravity wave.

在大气层结比较稳定的情况下，如果基本气流在低层和高层较大(有可能存在低空急流和高空急流)，此时产生的β中尺度不稳定扰动相对于基流向东传播，甚至于快速向东传播。基本气流在垂直方向上的风速切变对于中尺度横波型的扰动起着不稳定的作用。如果考虑基流的二次切变，可以得到涡旋Rossby波的相速度表达式，涡旋Rossby波相对于基本气流是单向传播的。涡旋Rossby波产生的物理根源是基本流场的风速二次切变，亦即基本流场y方向的平均涡度在空间z方向上的不均匀所致。涡旋Rossby波的相速度与纬向波数也有关，它的能量是频散的，其在纬向x方向也存在群速度。在基本流场的风速存在二次切变时，横波型不稳定可能是混合的涡旋Rossby重力波的不稳定；而在基本流场的风速仅仅存在线性切变，不存在二次切变时，横波型扰动的不稳定则是重力惯性波的不稳定。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。