衰减

The retardation coefficients are 2.22 and 1.74 of silt medium and sand medium respectively. According to first-order reaction, s total natural attenuation rates constant are 0.0635/h and 0.0059/h respective of silt medium and sand medium.

根据一级动力学方程计算得出，硝基苯在淤泥介质中的自然衰减总速率常数为0.0635/h，在砂砾介质中的自然衰减总速率常数为

Compared to wet season, arsenic is difficult to mobile in dry season. Attenuation constant in dry season is 0.3082(1/km), but it is 0.0569(1/km)in wet season. If initial concentration of As was 500μg/L without other contamination source in down stream, arsenic would deceased to 50μg/L in down stream 7.5km in dry season but 40km in down stream 40km. As is dominate species in river running throμgh mining area.

砷在枯水期较丰水期难以迁移，通过计算得到，在枯水期砷的衰减系数K值为0.3082(1/km)，而在丰水期为0.0569(1/km)；在污染口浓度达到500μg/L时，下游没有其它的砷的污染源(或会影响砷衰减的其它污染源)时，枯水期砷会在下游7.5km之后浓度降到50μg/L，而丰水期则要在下游40km之后才能降到同样的值，所以在丰水期砷污染的影响的流域更广。

The rules of the cold-test characteristics changing with helix pitch are also studied and it turns out that, with increasing helix pitch, the phase velocity increases linearly, the interaction impedance changes nonlinearly and the attenuation constant decreases nonlinearly. At the same time, with the limitation of the synchronism between the electron beam and the electromagnetic wave, the change of pitch is small and therefore an approximate linear relation can be introduced.

研究表明：相速几乎随螺距增大而线性变大，互作用阻抗与螺距是非线性的关系，衰减常数随螺距增大而非线性地减小；由于在维持电子注与电磁波速度同步的限制下，螺距变化的幅度不可能很大，因此可近似按线性关系来处理互作用阻抗及衰减常数与螺距之间的关系。

From the lumped equivalent circuit model, the phase shift/attenuation and impedance characteristics of the novel structure are first analysed based on the Bloch theory, which shows the novel structure has properties analogous to those of a bandpass filter: the attenuation constant keeps zero with a continuous and smooth characteristic impedance distribution within the passband and the bandwidth may be arbitrarily specified; characteristic impedance is purely imaginary with the inhibition of the electromagetic wave propagation outside the passband.

首先从一般的等效电路模型出发，根据Bloch周期性理论对该结构的相移、衰减和阻抗特性进行了分析，结果表明该新结构具有类似带通滤波器的特性：通带内衰减常数为零，特性阻抗为实数并随频率连续平滑分布，具有可任意指定的阻抗匹配带宽；带外特性阻抗为纯虚数，电磁波传播受到抑制。

Strata quality factor and attenuation factor especially these of near surface, are studied.

对松辽盆地南部的地层品质因素和地层衰减系数、尤其是近地表的地层品质因素和地层衰减系数进行研究，进而研究了野外地震采集的激发和接受等各个因素。

The anisotropy of phase velocity, quality factor and attenuation were studied, and then, the effect of attenuation anisotropy of the cap rock on AVO analysis was investigated.

目前，对介质衰减各向异性性质的研究主要集中在均匀介质中，而衰减各向异性对反射地震数据的影响则较少考虑。

In this paper the influence of coma and spherical aberration on the far-field distribution and antenna receiving power is analyzed, in which aberration attenuation factor is introduced and the relation of it to root mean square of wavefront aberration is given.

分析了球差和彗差对信号光远场分布、天线接收光功率的影响，引入了畸变衰减因子，给出了畸变衰减因子与波前畸变均方根值的关系。

The compensator was H = 2370s . The results of simulation showed that attenuation factor of the first order of the third control system was as much as ten times of the value of the system without controller.

通过仿真表明，采用速率传感器，在前三块帆板上布置压电驱动器时，一阶最大衰减因子为无控时的10倍，可以使脉冲衰减时间缩短15倍。

In order to make the microstrip equalizer matchs the given attenuation curve respectively ,it should be attenuation adjustable and quality factor adjustable besides frequency adjustable.

摘要为了使微带均衡器满足衰减特性与给定的误差曲线逐点拟和的要求，就必须使其频率可调、衰减可调、品质因数可调。

The research progress in SRM attenuation is presented in this paper, and also the SRM future research direction.

本文给出了表面多次波衰减方法的研究现状的系统阐述，并分析了表面多次波衰减研究的发展趋势。

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。