地震仪的

In the surveys, some very closely spaced survey lines displayed remarkable differences in crustal structure. To find the reasons for the differences and to analyze the reliability of crustal structure, ocean bottom seismometer data from the west and east sides of the Dongsha Islands were reprocessed and inverted with tomography technique. The routine processing and inversion procedures include clock correction, position correction, finite-difference ray-tracing-based tomography, checkerboard test and comparison of the inverted crustal model with initial models. As a key step, we analyzed the lateral velocity resolution and smoothed out the short wavelength velocity variation which maybe most probably artifacts in the final velocity models.

在一些相隔很近的测线上，探测的深部地壳结构却相差较大，为了分析这些探测结果中差异的原因和地壳结构变化的可靠性，本文以东沙东侧海域测线和东沙西侧海域测线为例，对采集的海底地震仪记录进行了时间、位置校正和初至波走时拾取，利用有限差分地震走时层析成像进行了走时反演，获得所在剖面的地壳速度结构，并分析了模型的横向分辨率，剔除模型中短波长的横向速度变化。

Based on VHZ data recorded by 7 stations of China digital seismograph network for Nov. 14, 2001, earthquake in the west of the Kunlun mountain pass, we extracted spherical mode of 0S4-0S76 of the earth free oscillation using power spectral density estimation. Because the frequency response of seismograph in China digital seismograph network suppress information of solid tide, we do not need to remove the solid tide in our procession.

利用中国数字地震台网改造后的7个台站的VHZ波形资料，采用功率谱密度估计方法，利用中国数字地震台网地震仪对低频信号压制的特点，在没有对资料去除固体潮影响的情况下，提取了2001年11月14日昆仑山口西地震激发的0S4-0S76地球球型自由振荡，并与地球初步参考模型的理论自由振荡周期进行对比，结果表明与PREM预测的球型自由振荡周期符合得很好。

Quantitative research on effects of seismic source on space correlation of strong ground motion;2. The abecedarian analysis gives out the basic reason of why the earth vibrant noise can be regarded as a new seismic source of the future flat seis.

在已经进行的两次探索性观测试验中，得到运行列车引发的地振动噪声可以通过天然地震观测台站和地震勘探常规地震仪接收到的证据，通过对数据的初步分析，进一步提出运行列车引发的地振动噪声可能成为铁路沿线浅层地震勘探震源的基本理由，并给出需要进一步深入研究的问题。

So we designed a adaptive synchronizing controller based on hereinbefore hardware environment: first a small magnitude reference signal r is outputted to system through the signal card (to ensure that the vibrating system works in a linear state), and this signal is sent to the moving coil of vibrator through the power amplifier, so vibration is produced through electromagnetic induction. Secondly the vibration signal can feedback to the data acquiring card in the servo system through the acceleration sensor on the Vibroseis reactor M〓 and the base-plate M〓, then the computer can get the current vibrating state y〓 of the coil of vibrator according to the feedback information from the data acquiring card, and give a real time comparing between the current state y〓 and the reference output y〓 of the set-in reference model with current reference input being r , then regulates the correlative controlling parameters according to the error e〓=y〓-y〓 till y〓→y〓, finally normal signal sweeping begins with a certain phase fixed. Meanwhile a synchronization signal for seismic signal record is sent to seismograph from synchronization signal outputting component in the Vibroseis system to perform the controlling process of synchronization of sweeping phases.

为此，我们基于以上的硬件环境设计了一个自适应同步控制器：首先通过信号发生卡对系统输出小幅度的参考信号r(从而保证振动系统工作处于线性状态)，信号通过前置放大器、功率放大器等送到激震器动圈，并通过电磁感应产生振动，振动信号通过可控震源激震器反应块M〓和基板M〓上的加速度传感器反馈给伺服系统中的数据采集卡，工控计算机根据采集卡的反馈信息，获取当前激震器动圈的振动状态y〓，并实时地将该状态与内置的参考模型在当前参考输入r下的参考输出y〓进行辨识，再将两者输出误差e〓＝y〓-y〓对系统的有关控制参数进行调整，直至y〓→y〓，最后在经过某一固定的相位后，开始信号的正常扫描过程，与此同时，由可控震源系统的同步信号输出部件向地震仪送出一地震信号记录同步信号，进而完成扫描相位同步控制过程。

The tenet of Vibroseis seismic exploration is outputting as much energy through a continuous bestirring in a period of time as that outputted by other sources in an instantaneous time. The realization of this goal needs that Vibroseis can output a same sweeping signal in many times continuously, then overlap the reflect signal to eliminate the noise from the exploration background, finally visualize the structure of the stratum.

可控震源地震勘探的精髓便是通过系统长时间的持续激励来实现其它震源的瞬时高能量激励，实现这一目标的前提是要求震源系统能够完成相同扫描信号的多次无差别输出，进而通过地震仪进行相应的垂直叠加，充分压制背景噪声，凸现地下的有用构造信息。

Meanwhile, in North America, the EarthScope project is establishing a continent-wide network of GPS locators, seismographs, and other instruments to study whats happening below the crust.

与此同时，在北美开展的&地球透镜&计划正在建立一个包括全球定位系统定位仪、地震仪和其他仪器所组成的洲际范围的网络，以研究地壳下面的活动情况。

Meanwhile, in North America, the EarthScope project is establishing a continent-wide network of GPS locators, seismographs, other instruments to study what's happening below the crust.

与此同时 ssb§bww.com ，在北美开展的&地球透镜&计划正在建立一个包括 www 。ddd tt。 com 全球定位系统定位仪、地震仪和其他仪器所组成的洲际范围的网络，以研究地壳下面8ttt8的活动情况8tt§t8.com 。

Seismographs placed on the moon have detected only a very low level of moonquakes. This is in sharp contrast to the earth, which is still very much alive with volcanism, mountain building and drifting continents.

目前由安装在月球上的地震仪测得的&月震&的次数极少，这与地球上火山活动频繁、山脉不断上升、大陆漂移不定的情况形成鲜明对照。

We also discuss observations of infragravity waves on broadband ocean bottom seismometers located off-shore California, and their relationship to wind waves and seismic noise, showing that the ocean/solid earth coupling occurs near the coast.

我们也讨论了在加州近海布设的宽频带海底地震仪观测到的重力波以及它们与风波和地震噪音的关系，发现海洋/陆地的耦合发生在近海。

The main factor that affects the resolution of seismic prospecting is Earth's absorption and attenuation effect on high frequency signals. Study and calculation of Earth's absorption and attenuation effect show that medium deep and deep reflectors over 135 Hz can not be recorded even by 24-bit seismometers.

地震勘探分辨率不高的主要原因是地层对地震波高频成分的吸收衰减，通过对地层吸收衰减深入的理论计算可知，既便使用 2 4位遥测地震仪，在中深层勘探中也无法记录主频超过 13 5Hz的地震波。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。