震源

Totally, 21 earthquakes have been relocated at depth of 50~80 km which was very near the Moho.

发现区域震源深度呈明显的双层分布，其中有21 个地震的深度在50～80 km之间，与该地区的莫霍面深度相近。

The difference is found between DD and the master event technique, multiplet relative relocation as well as the hypocentroid decomposition, the condition that span between events is much less than the event-station distance is must be satisfied for latter but not for former when the velocity lateral heterogeneity is not so strong.

研究认为：双差法与主事件法、多重相对定位法以及震源矩心分解法不同，在速度变化较弱的地区它并不需要满足事件之间的距离远小于事件到台站距离这个条件。

Mantle discontinuities ; Rectilinearity polarization filtering ; N th root slant stack ; Focal depth modification ; Subduction slab.

地幔间断面；线性-偏振滤波； N次根倾斜叠加；震源深度校正；俯冲带

The characters of the nappe structure may control the locations of the focus and epicenter as well as the other features.

构造带的推覆构造特征很可能控制了地震震源深度、震中区与烈度区的不同位等特征。

Vibroseis that is capable of exciting high frequency signals and is of strong noise immunity has been widely used in petroleum industry both at home and abroad.

石油地震勘探使用的可控震源可以激发高频信号，并具有较强的抗干扰能力，已在国内外广泛使用。

It is found that these earthquakes are concentrated in the meizoseismal area. The direction appears north by west and depth is about 7 km.

结果显示：地震震中集中分布于郭家坝M3.8地震的极震区，方向呈北偏西，震源深度约7km。

Through the analysis of frequency and bandwidth, the optimal excitation position was got to guide the resettlement of the actual source.

通过分析远场子波的主频及频宽得到最佳激发位置，来指导实际震源的安置。

It seems the change of the focal mechanism of the small earthquake may indicate some precursory meanings.

小地震震源机制显示出的变化，表明它们对于强震孕育发生非常灵敏。

The land-sonar is presented in this paper, which is based on the principle of elastic reflection wave and is a method of geological forecasting in tunnel construction.

作为地震反射法一个变种的陆地声纳法，是一种易掌握、仪器轻便的隧道掌子面前方地质预报的方法，它用锤击震源在隧道掌子面上设排列和测点工作，在预报岩溶、断层及破碎带、岩脉等方面成功地进行了20多个工区的预报，1995年通过了铁道科学院和铁道部鉴定。

In the work, employing a function with four undetermined parameters to model the source wavelet, an analytical relation between Q-factor and envelope peak instantaneous frequency is derived from the theory of one-way waves propagating in an anelastic medium; at the same time, a method for extracting instantaneous frequency in wavelet domain is developed for improving the precision and anti-noise performance of IF estimation, and based on these, a method called EPIF in wavelet domain is proposed for estimating Q-factor of VSP data.

本文采用一个具有4个待定参数的函数去逼近震源子波，利用黏弹介质中单程波传播理论推导出了地震子波包络峰值处瞬时频率和品质因子之间的解析关系；同时，为提高瞬时频率的估计精度和抗噪性能，在小波域中发展了一种计算瞬时频率的方法，并在此基础上提出了估算VSP资料Q值的方法，简称小波域包络峰值处瞬时频率法。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。