衰减

Generally speaking, the high group velocity and low attenuation factor and high Q〓 in the same area, but relatively low group velocity and high attenuation factor and low Q〓 in the same area in China is the general distribution.

在不同周期，面波衰减系数或品质因子在整个中国大陆区域分布是不均匀的；总体表现为高群速度分布的区域呈现高Q〓和低衰减系数、低群速度分布的区域呈现低Q〓和高衰减系数分布的特点。

Results: The attenuating rate of the peak value of acceleration at the heel of SYS-2 varied between 24.6 % and 85.8 %. The attenuating rate of average acceleration was from 34.2 % to 87.7 %, and the attenuating rate increased with the decline of pulse input width of the shock.

结果：舰艇防冲击鞋后跟部位加速度峰值的衰减率为24.6%～85.8%，平均加速度衰减率为34.2%～87.7%，衰减率随冲击输入脉宽的减小而逐渐增大。

Researched influence of frequency on characteristic of electromagnetic wave transmission in tunnels, and analyzed characteristic of electromagnetic wave transmission in circular, arches and curved tunnels by method of metal wave guide, and gives approximate formulas of attenuation rate. Main conclusions we obtain are as follows: in circular,rches tunnels, if frequency is higher, attenuation rate is smaller, it is beneficial for EM waves to transmit, in curved tunnel, higher frequency, more attenuation rate ...

研究了频率对井下电磁波传输特性的影响，采用金属波导法分析了圆形、拱形及弯曲隧道中电磁波的传输特性并给出衰减率近似公式，得出主要结论：在圆形和拱形隧道中，频率越高，衰减率越小，越有利于电磁波的传播；在弯曲隧道中，频率越高，衰减率越大，不利于电磁波的传播；通过特性曲线与井下实验数据相比较得出在900MHz左右为井下无线通信系统传输信号最佳频段。

The fit of the decrement to the simulation was done with the burdening decay experiment, and the curve and equation of the decrement was found.

通过载荷衰减实验对模拟所得结果进行了衰减量的实验数据拟合，得出了衰减量的曲线和方程式。

This study examined the alumina ceramic membrane to deal with high turbidity water flux changes in the law of decay was found in the early running flux decay rapidly, the latter tends to slow decay, a linear decline in the overall. 51qikan.

Key words： high-alumina ceramic membrane separation of water turbidity摘要：本实验研究了氧化铝陶瓷膜处理高浊度水时膜通量衰减变化规律，发现运行初期膜通量衰减很快，后期衰减趋于平缓，总体成线性下降。

Results revealed that the large side insulation of the stator bar in slot is available for ultrasonic pulse-echo testing; Coupling transducer on the surface of a practical stator bar could minimize the influence on the measurements of velocity, contributing no destructivity of the ultrasonic testing for stator insulation; The simultaneity of same velocity and higher attenuation can be used to detect insulation delamination from conductors; Compared with the wide sides of the bars in slot, the short sides of the bars near the exit from slot and the end bars had a same velocity and a higher attenuation; The velocity might be exactly measured on the shot sides of the bars near the exit from slot and the end bars, while the attenuation might not, which were examined though filed tests; V min decreased greatly and V av decreased slightly with the service time of the bars.

在实验室对线棒多种结构处的主绝缘和不同运行年数(未老化、16、18 和23年)线棒的主绝缘进行了低频超声反射法检测试验，并进行了现场试验，发现(参见 Hao et al， IEEE DEI， to be published)，槽部线棒的宽面绝缘不受换位绝缘的影响，比窄面绝缘更适合超声测量；线棒表面平滑的半导体层减小了耦合剂对超声测量的影响，实现了无损性；波速不变而声衰减减小可以检测线棒出现绝缘与导体脱壳缺陷；出槽口和端部线棒的窄面绝缘与槽部线棒的宽面绝缘相比，声衰减大而波速一致；现场试验验证了波速不受绝缘结构和现场测试条件的影响，而声衰减受以上因素影响很大(参见 Hao et al，中国电机工程学报， Vol.23 No.4)； V min 随运行年数明显减小， V av 随运行年数慢慢越小。

In this paper, effects of atmospheric factors to Ka-Band earth-space links are analyzed, and the total fade distribution function is derived. With the scintillation prediction model, monthly averaged standard deviations and monthly percentage time averaged fade of scintillations for some of referential earth stations of our country are computed.

摘要本文分析了各气象因素对Ka-波段地空链路衰减特性的影响，得出了链路综合衰减分布函数，利用闪烁预测模型计算了全国各参考站点的闪烁月平均标准偏差和月百分比时间平均衰减值。

Based on the theory of heat conduction, the heater thermal field was calculated to determine the most efficient position of heater. And the parameters of heater and asymmetric Y branch were decided using FD-BPM method. After the design and optimization, the polarization dependence and wavelength dependence of the attenuator were researched.

先根据前文介绍的热传导理论模拟了用于可调衰减器的电极的热场分布，设计了电极的最优位置，然后利用马卡蒂里近似解法求解掩埋条形波导的单模条件，并计算了波导的宽度和厚度，设计了非对称Y分支型的光衰减器的Y分支结构，电极参数，完成整个设计过程，最后，模拟了光衰减器的偏振相关性和波长相关性，从而也得到了一个聚合物可调光衰减器的设计优化方法。

The theories of cuneiform prism and series neutral glass slices used as laser attenuator are analyzed in this paper. An aberration-free laser quantitative attenuator made of cuneiform prism is adopted and a series of neutral attenuated slices are used for adjusting laser-beam enegy at the same time.

分析了楔形镜和中性玻璃衰减片组对光束的衰减原理，采用反射式楔形镜作为无像差定量衰减器，并同时使用中性玻璃衰减片组微调光束能量。

Presence of multiples leads to poor quality in main stages of offshore seismic data processing, such as velocity analysis, stacking and imaging. Three basic multiple attenuating methods are reviewed; and a more effective multiple attenuator is achieved by joining them. As the first step, shot or receiver records are extrapolated by wave-equation datum algorithms. The extrapolation will establish a model of waterbottom multiples. Waterbotton multiples will then be removed by subtracting the extrapolated records from the original records. After that, predictive deconvolution is used to attenuate the multiples created by source ghost. Finaly, RADON transformation is adopted to separate peg-leg multiples and residual water-bottom multiples from the original data in the τ-p domain.

地震勘探尤其是海上地震勘探中存在着各类多次波，由于多次波的存在严重影响了速度分析、叠加、偏移成像等地震资料处理，海上多次波主要有全程多次波和层间多次两大类，为了压制海上不同类型的多次波，本文首先分析波场外推、预测反褶积和拉东变换衰减不同多次波的理论基础，然后联合采用这些方法，分别衰减全程多次波和层间多次波；即：首先对炮记录或者接收点记录进行波场外推，建立海底多次波模型，预测并减去全程多次波，然后利用预测反褶积衰减掉周期性明显的多次波，最后将数据转换到τ-p 域，用拉冬变换根据同一时间多次波和有效波在速度等方面的差异，进一步分离层间多次波和剩余的全程多次波，并在该域中切除分离出的多次波，从而实现联合多次波衰减处理。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。