查询词典 P wave

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 the decompositions to common-shot gathers and common-offset gathers, one can obtain common p, plane wave gathers and common P plane wave gathers which are suitable to the single square root extrapolation equation and the double square root extrapolation equation, respectively.

通过对共炮点道集和共偏移距道集地震数据的平面波分解，分别得到适用於单平方根波场外推方程和双平方根波场外推方程的共P平面波道集和共P平面波道集。

By measuring the velocity of the P wave and S wave on the three orthotropic different directions including parallel and vertical direction to the stratum of the compacted rock samples including slate, phyllite, mylonite and metasandstone, the two obvious anisotropy effects of P wave and S wave velocity are put forward.

通过对板岩、千枚岩、糜棱岩和变质砂岩等4种岩石在平行和垂直层理、板理的3个正交方向上的纵、横波波速试验，提出了致密岩石纵波波速的各向异性与横波波速的各向异性普遍存在着一致性和差异性两种特征。

By measuring the velocities of the P-wave and S-wave in three orthotropic directions including parallel and vertical directions to the stratum of the rock samples for slate, phyllite, mylonite and metasandstone, and based on the wave velocities of other rocks from the relevant studies, the anisotropic effect of wave velocity ratio of the P-wave and S-wave for most rocks is put forward.

通过对板岩、千枚岩、糜棱岩和变质砂岩等4种各向异性岩石在平行和垂直层理或板理的3个正交方向上进行大量的纵、横波波速试验，并结合对相关文献中己有岩石波速数据的深入分析，提出岩石介质纵、横波波速比的各向异性效应。这种效应广泛存在，其发育程度受到岩石类别的控制。

Firstly, radial horizontal component and transverse horizontal component are derived from tri-channel seismic data at the surface and the bedrock in borehole array by back-azimuth decomposition method, and the histories of radial and vertical components are divided into two parts by Sg wave arrived time. Moreover, it is supposed that transverse horizontal components are made up of SH wave, while vertical component and radial horizontal component are constituted by P-SV wave system.

针对钻井台阵的两处三分量加速度记录，根据反向方位角将两水平分量分解为径向水平分量和横向水平分量，假设横向水平分量由SH波系组成，竖向分量和径向分水平量由P-SV波系组成。

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。

The techniques of using S-wave response to investigate fractured anisotropy medium have achieved good results in practical application. However, these techniques are very complex and expensive, and then limited their application. Whenas various P-wave attributes are effectively preserved by accurate P-wave acquisition and processing techniques, thus it creates a beneficial condition to detect fracture using P-wave data.

利用横波响应进行裂缝性各向异性介质的检测在实际应用中取得了很好的效果，但技术复杂、成本较高使该方法的广泛使用受到限制，而纵波资料采集和处理技术的精细有效保持了纵波的各种属性，这为直接利用纵波资料进行裂缝检测创造了条件。

objective to evaluate efficacy of extracorporeal shock wave lithotripsyfor treating ureteral stones in situ,investigate the cause of higher re-treatment rate.methods total of 687 patients with ureteral stone were received eswl between january 2000 and december 2004,included 455 male(66.2%) and 232 female(33.8%) patients,6 cases have bilateral ureteral calculi,12 cases have unilateral multiple calculi.hence,together 709 ureteral calculi were treated.patients upper ureteral calculi were treated in the supine position,for lower ureteral calculi patients were turned prone.to reduce eswl-induced renal trauma and pain,using lower energy source,adjusted power setting from 9.8 to 13.2kv,limited 1500 shock wavs per one session.no auxiliary procedure were used before eswl.the stone size was measured as the surface area of stone length by stone width on x-ray film.the interval between two treatment sessions was two weeks.results of 709 ureteral calculi,the overall stone free rate was 97.3%(690 calculi),re-treatment rate was 34.1%(292 calculi).according to the performed treatment sessions,one session 467 calculi,the mean stone size 37.27mm2,stone free rate 65.4%(464 calculi).two sessions 138 calculi,the mean stone size 62.48mm2,stone free rate 18.4%(131calculi).three sessions 52 calculi,the mean stone size 79.60mm2,stone free rate 7.1%(50calculi).four sessions 19 calculi,the mean stone size 101.63mm2,stone free rate 2.4%(17calculi).fivesessions 33 calculi,the mean stone size 119.33mm2,stone free rate 3.9%(28 calculi).overall 19 cases(2.7%)turned to other treatment modalities.of 335 upper ureteral calculi,303 achieved stone free (95.8%),re-treatment rate was 38.5%(129 calculi).of 374 lower ureteral calculi,369 achieved stone free(98.7%),re-treatment rate was 30.2%(113 calculi).the re-treatment rate of upper ureteral calculi was higher than lower ureteral calculi(p＜0.05,χ2=5.40).the difference of stone-free rate between upper and lower ureteral calculi was no significant(p＞0.05,χ2=0.15).conclusion eswl should be considered first line therapy for ureteral stone still.stone burden are the main variable of higher re-treatment rate,upper ureteral stone may moving with respiring during eswl.so efficinet shock wave was decreared,re-treatment rate become higher.

目的 评估体外震波碎石治疗输尿管结石的疗效，探讨再治疗率高的原因及输尿管结石的治疗选择。方法回顾2000年1月～2004年12月间eswl治疗输尿管结石的临床资料687例，男455例（66.2%），女232例（33.8%），平均年龄46.6岁（15～83岁）。有双侧输尿管结石6例，单侧多发性输尿管结石12例（4颗1例，3颗2例，2颗9例），共计输尿管结石709颗（含透光结石13颗）。应用上海爱申公司生产的desunit6030型碎石机，c臂x线球管做结石定位。上段输尿管结石（肾盂输尿管交界处至骶髂关节上缘）取仰卧位，下段输尿管结石（骶髂关节上缘下至输尿管口）取俯卧位。为减少eswl引起的肾损伤和疼痛，应用较低的能量，震波发生器电压从9.8～13.2kv，震波频率1.5s。每次治疗设定为1500次震波。治疗后3天摄腹部平片或b超，以后每隔7日重复检查。假如结石未碎或有残留结石最长径＞3mm以上，再次eswl，两次治疗的间隔时间为两周。结石的大小用x线片上的表面积（mm2表示。结果 709颗输尿管结石总的治愈率为97.3%（690颗），再治疗率34.1%（242颗）。其中一次治疗467颗，平均结石大小37.27mm2，治愈464颗（65.4%），3颗改治疗；两次治疗138颗，平均结石大小62.48mm2，治愈131颗（18.5%），7颗改治疗；第1和第2次治疗治愈率（1个月治愈率）为83.8%。3次治疗52颗，平均结石大小79.60mm2，治愈50颗（7.1%），2颗改治疗；4次治疗19颗，平均结石大小101.63mm2，治愈17颗（2.4%），2颗改治疗；5次及5次以上治疗33颗，平均结石大小119.33mm2，治愈28颗（3.9%），5颗改治疗。总计19颗（2.7%）结石改变治疗方式。上段输尿管结石335颗，治愈321颗（95.8%），再治疗129颗（38.5%）。下段输尿管结石374颗，治愈369颗（98.7%），再治疗113颗（30.2%）。经χ2检验，上、下段输尿管结石的再治疗率差异有显著性（χ2=5.40，p＜0.05），治愈率差异无显著性（χ2=0.15，p＞0.05）。不良反应：血压升高13例（1.9%），震波区域疼痛26例（3.8%），震波进入处皮肤点状淤血33例（4.8%），肉眼血尿128例（18.6%），均于第2、3天自行消失。结论 eswl目前仍是输尿管结石的第一线治疗，结石的大小是再治疗率高的主要因素。结石的位置有影响，上段输尿管结石可随呼吸移动，有效震波次数减少，再治疗率比下段输尿管结石高。eswl前注重病例筛选可降低再治疗率。

Under certain ratio of signal-to-noise and through the computer simulations and calculations, the performances in Mbius digital base band communication system of five often used modem function set, those are the even and odd symmetrical triangle wave, even and odd symmetrical square wave and saw-tooth wave and their inverse transforms, are simulated 10000 times, and the fluctuation ranges of the error rate P(subscript b are observed.

在一定信噪比的前提下，通过计算机仿真和编程计算，对Mbius数字基带通信系统中偶对称三角波、奇对称三角波、偶对称方波、奇对称方波和锯齿波这5种常用的调制解调函数族及其逆变换进行仿真1万次，观察错误概率P

The nearsurface thicknesses, as seen by a P-wave and an S-wave, can be different. The watertable serves as a boundary for the P-wave near surface layer, but not necessarily so forS-wave which is unaffected by the pore fluid composition.

纵波和横波的近地表厚度不同，纵波的近地表层边界为潜水面，而横波不受孔隙流体影响，它的近地表层往往延伸到潜水面以下。

Finally, according to market conditions and market products this article paper analyzes the trends in the development of camera technology, and designs a color night vision camera.

最后根据市场情况和市面上产品的情况分析了摄像机技术的发展趋势，并设计了一款彩色夜视摄像机。

Only person height weeds and the fierce looks stone idles were there.

只有半人深的荒草和龇牙咧嘴的神像。