地震波

According to the forward and inverse results of synthesi zed seismic records, our Q filtrating operator of the depth domain is consis tent with the seismic laws in the absorbing media, which not only considers the effe ct of the media absorbing of the waves, but also fits the deformation laws, name ly the frequency dispersion of the body wave.

在深度域的Q滤波算子符合地震波在衰减介质中的传播规律，不仅考虑了介质吸收对地震波振幅的影响，而且还保证了所造成的波形畸变满足因果规律，即地震体波具有某种频散性质。

The principal evidence for a separate seismic event is coherence among the members of a set of seismic traces over a short time interval of the order of 1-1 /2 or so cycles of the dominant frequency compared with less coherence elsewhere.

一地震波组中单个地震波相位与该组波相关的主要依据是与其它相关性差的地方相比它们之间有一很短的时间间隔约为 1-1 /2 36 Seismic 个主频周期。

The acceleration and sound pressure on the surface of seafloor are obtained.

建立了点声源作用下海底地震波的时域数值计算模型，利用该模型，对二维半无限空间简单海洋模型的低频点声源海底地震波问题进行了数值模拟，得到了海底表面处的加速度和声压值。

As we all know that swing,frequency and duration are three factors of natural seismic wave,many seismologist have done much in-depth research about them and obtained plentiful theoretical results.

我们知道，在天然地震中，振幅、频率以及持续时间是地震波的三要素，许多地震学者对这些已经做了很细致深入的研究，取得了不少的理论成果，而对爆破地震波的研究还处于试验性阶段，相关方面的文献资料也非常有限。

In the aspect of the study of the application of HHT method, This dissertation has done three part of jobs: first, the Elcentro strong ground motion which is in common use in earhtquake engineering is analyzed by HHT method, getting its amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; second, the typical nonlinear system defined by the Duffing equation is analyzed by HHT method, getting its numerical value's amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; third, define the stationary degree of non-stationary signals making use of 3-D time-frequency spectrum and marginal spectrum, the stationary degree curve of Elcentro seismic recording is protracted according to its defining formula, the stationary degree curve of Elcentro seismic recording which change with time is protracted according to similiar definition.

在HHT方法的应用研究方面，本文做了三部分的工作：首先，利用HHT方法分析了地震工程中常用的Elcentro非平稳强震记录，得到了该记录的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；其次，应用HHT方法分析了典型的非线性系统－Duffing方程，得到了该方程数值解的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；最后，利用三维时频谱与边际谱定义了非平稳信号的平稳度，并依照其定义式绘制了Elcentro地震波记录的平稳度曲线，依照类似与依赖与频率变化的平稳度定义，初步尝试编程绘制了Elcentro地震波随时间变化的平稳度曲线。

Under the frame of Hamiltonian, the propagation of seismic wave is a symplectic group transformation with one parameter and consequently, the numerical calculation methods of the propagation ought to be symplectic method.

在哈密顿表述下，地震波标量方程描述的波场随时间的演化过程为波场在单参数辛群作用下的变换过程。因而在计算地震波场随时间的演化时，为保持系统的辛性质，应采用辛几何算法。

Firstly the Lie group description and method of seismic wave propagation in phase space is proposed, which is, in other words, symplectic group description and method for seismic wave propagation, since symplectic group is a Lie subgroup and symplectic method is a special Lie group method.

文中首先给出相空间中地震波的李群表述和算法，也即地震波的辛群表述和辛算法，辛群是李群的子群，辛算法是特殊的李群算法。

Analysing and comparing the relationship between the seismic displacement and EM coseismic signals,the mechanism of EM coseismic signal generation appear to be driven by seismic waves.

通过与汉王强震台的地震记录数据中15个强震记录比较发现，与地震波相对应的地震同震电磁信号存在于所有的电场和磁场记录分量中，它们与地震波到达同步。

Although seismic waves traveling through the Earth act as a low_pass filter and smooth out some small indeterministic components, those statistic in other words self_organized features exist underground.

中型和大型尺度结构构造分区性，使得地球内部介质地震波速度表征出大尺度的确定性模型，而小尺度上微孔和裂隙的存在会导致地震波速度分布的随机扰动，即自组织模型。

The computational cost of the scheme is greatly reduced comparing with pseudospectral modeling of the two-way equation.

就模拟一次反射地震波而言，与前人研究的双程波动方程伪谱法地震波模拟相比，本文算法具有足够高的模拟精度，且计算效率成倍地提高。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。