首波

首先对其首波PN进行分析，结果表明其线性关系较好，计算出的速度值与华南地区近震走时表中所用的地壳模型中的速度值一致。

First , we analyze the head wave PN , it shows that it 's good in linearity relation , and the value of PN velocity counted out is same to the crust model using in the list of pass time of HuaNan seism .

固井首波检测及程序

The Head Wave Detection and Its Program for Cemented Well

建立CT反演中由超声波信号提取首波时间的拾取方法。

Established the method of extracting first arrival time from the ultrasonic signal in the process of CT inversion .

最后以超声波在混凝土样本中穿透传播的首波时间为反演投影数据进行图像2D重建，实现了混凝土超声探伤的可视化。

Later , the first-arrival traveling time is used as the original projection data in 2D ultrasound CT imaging reconstruction .

使用的资料是多个台站记录到的多个地震，所用的震相是Moho面的反射波P11和首波Pn。

ACCURATE ESTIMATION FOR ARRIVAL TIME OF SEISMIC WAVE A great deal of events recorded by several stations arc used , mainly the reflected wave Pn and head wave Pn from Moho .

以超声波穿透混凝土传播的仿真首波走时数据为投影物理参数，分别实现了奇异值分解法和美国OLSON公司UPV系统自带的成像软件重构2D超声CT图象。

Using the first-arrival traveling time abstained by experiment and simulation as original projection data in ultrasound CT reconstruction , reconstructed by SVD method and OLSON company 's software .

根据1975年1月至1993年12月发生的3级以上416次天然地震近震首波Pn走时数据，分析了山东及邻区上地幔波速各向异性的特征。

Based on Pn travel time from 416 nature earthquakes of their scale Ms > 3 happened from January 1975 to December 1993 , wave velocity anisotropy of the upper mantle is analyzed with residual calculation method .

采用首波等幅法可对2×2×3cm的标准试样进行有效的检测，解决了小试样不易测试的问题。

We adopted the new method , which is named " equal spoke of first wave " and checked 2 × 2 × 3cm standard samples successfully , so it is possible to check the little samples .

一般情况下，正常密度与高密度在固井质量良好的条件下，其CBL衰减率比低密度都要高，其套管波首波幅度值都应该比低密度小；

Generally , under conditions of good cement job quality the CBL decay rate of normal density and high density admixture cement is higher than that of low density admixture cement and the head wave amplitude of casing wave is lower .

对于美国、英国、日本、德国和法国的首波买家而言，iPhone4最大的吸引力在于该设备能够进行视频通话，尽管目前只限于和其它iPhone4所有者通过WiFi网络进行交流。

The top draw for iPhone 4 's first wave of buyers in the US , UK , Japan , Germany and France was the ability to make video calls on the device , though that is for now limited to communications with other iPhone 4 owners via WiFi networks .

阵列声波测井信号调理与首波提取技术研究

Research of signal process and detecting head wave of acoustic array

测井声波首波检测及其相关性校正

Detection and Correlation Correct of First Arrival in Digital Acoustic Array

利用首波重建基底速度图象

Reconstruction of the basement velocity image based on head wave

声波测井中首波的物理机制

The Physical Mechanism of Head Waves in Acoustic Well Logging

声波测井中首波的临界折射波至模型

The Critical Refraction Wave Arrival Model for Acoustic Head wave

用纵波首波幅度识别砂岩气层的方法

Identification of gas-bearing sand formation using the amplitude of head P wave

超声波首波相位反转法检测混凝土裂缝深度

Crack Depth Detection in Concrete by Ultrasonic Initial Wave Phrase Reverse Method

声波测井中首波共振理论的实验验证

Experiments on the Head Wave Resonance Theory in Acoustic Logging

利用首波到时评价水泥胶结质量的模拟实验研究

Experimental Investigation on Cement Bond Evaluation Using First Arrival

水泥胶结评价中地层波首波能量的提取

STRATUM Extraction of head wave energy for formation wave in cement bond evaluation

赝首波特性的模型实验及其与爆破资料的对比

Model experiments on the character-istics of PSEUDO-HEAD waves and their comparisons with shot data

提出了首波波幅的识别与追踪方法及其适用性。

It also discusses the recognition , tracing and applicability of head wave amplitude .

首波地震层析技术可以揭示浅表岩体形态。

The head-wave tomographic imaging may reveal the morphology of the shallow-surface rock bodies .

广义首波和下行首波的实验研究

Study of generalized and downgoing head waves

纵、横波首波的相位始终相反；

The phases of the P and S - head waves are opposite all the (?)

数值分析表明，次首波受首波后续波和伪瑞利波的影响较大；

It is also shown that theshear waves are affected by the compressional and Pseudo-Rayleigh waves .

含气饱和度对纵波首波速度、振幅及主频影响的实验结果

Experimental results about influence of gas saturation upon compressional head wave velocity , amplitude and dominant frequency

关于超声首波相位转变检测砼裂缝深度的研究

Research on inspection of the concrete crack depth by the phase change of the first ultrasonic wave

研究结果表明，该区不同界面的首波和反射波具有不同的特征。

The result shows that the head waves and reflected waves from different interfaces in this region possess different characteristics .

纵、横波首波相位关系实验现象的解释及其对全波测井的意义

Interpretation of the Experimental Phenomena about the P and S-Head Wave Phase Relations , and Its Significance to Full Wave Logging