衰减

The relationships of pulse distortion depending on frequency, pulse width, rain rate and path length are studied .The conditions of the broadening and compression for pulse wave are given. Based on the scattering characteristics of fog, the attenuations and reflectivities at millimeter wave are computed and analyzed for radiation and advection fog. The attenuation along earth-space deduced by radiation and advection fog is obtained and the results are compared.

其次基于单个雾滴的散射特性，对毫米波段电磁波通过平流雾和辐射雾时产生的衰减效应特性和反射率进行了分析和讨论，通过分析预测雾衰减系数的常用经验模型，预测了毫米波段电磁波通过平流雾和辐射雾地空路径传播时的衰减特性。

By the study to the load decay at different temperature, according to the theory of time-temperature equivalent and WLF equation, the relation of load decay at different temperature was found.

而通过对不同温度下O形圈载荷衰减规律的实验研究，根据聚合物的时间—温度等效原理，利用WLF方程，建立了实验所用O形圈高温下的载荷衰减规律与常温载荷衰减规律之间的联系方程。

Downward wave amplitude decay in negative exponential function, but the upward wave amplitude is not the case.

下行波的衰减规律符合指数衰减，但上升波的衰减并不符合这一规律。

Theobserved strain is 10~2 times as local point strain at the same observed stress.This indicates that macroscopical symmetrical rock is quasi-brittle materialwith microcosmic heterogeneousness and its macroscopical mechanicalbehavior is the results of reciprocity and magnification between microcosmiccharacteristic, not simple sum.(4) The degree of irregularity of strain increases with the number of cycle.But degree of irregularity of transverse strain fluctuates larger at the samecycle. Moreover degree of irregularity of transverse strain is larger than that ofaxial strain. This shows that deformation and failure of rock is process ofevolvement of small crack. Small crack evolves from even and out-of-orderstatus to heterogeneous and ordinal status.(5) Ultrasonic speed decreases with the number of cycle. The decreasecourse is such: Firstly, ultrasonic speed fluctuates in a steady scope in somecycles; And then ultrasonic speed quickly decreases to a certain more smallvalue; Afterwards in succedent cycles, ultrasonic speed fluctuates about thevalue. That is to say, ultrasonic speed fluctuates and decreases at intervals ofcycles. In deformation process of rock, quantitative change and qualitativechange of its small crack evolvement carry through crosswise.(6) Strength and modulus of rock decrease with exponential function asscale of specimens increases.

同一表观应力下，局部点应变与表观应变相差可达2个数量级，表明宏观上均匀的岩石是具有细观特征的准脆性材料，其宏观力学行为是细观特征相互作用、放大的综合结果，而不是简单的叠加；(4)岩样轴向应变不均匀程度和横向应变不均匀程度随循环次数的增加渐进增大，但是在同一个循环内，横向应变离散系数随应力的变化波动较大，且同一循环级别下，横向应变不均匀程度大于轴向应变不均匀程度，表明岩石内部微裂纹的演化是岩石变形破坏的本质特征，这一演化表现为微裂纹从均匀无序分布逐渐向非均匀有序发展；(5)随循环次数的增加，所有岩样内部超声波速会出现衰减，衰减过程表现为在某几次循环内超声波速在某一相对范围内波动，然后急剧减小到某一较小值，在随后的循环内，超声波速又会保持在这一较小值附近波动，即超声波速表现为波动和急剧减小间隔形式衰减，表明从宏观看来平稳的岩石变形过程，内部结构演化过程(微裂纹发展及其相互作用)却表现为均匀量变和突发质变不断交叉进行的现象；(6)岩石强度和弹性模量随尺度增大呈指数函数规律减小。

Based on the latest intensity data of North China that include 48 earthquakes and 139 isoseismal lines, the attenuation relationship of seismic intensity is obtained.

除了(1)式之外，有的研究者还采用了如下形式的经验公式：I=A+BM-ln(R+R0)+ε(2)由于地震烈度衰减规律是通过对烈度数据进行统计回归而得到的，而使用衰减关系式进行的直接回归会存在种种不足，因此，前人根据地震烈度衰减的特点提出了不同的统计模型和方法。

At the same time, under the condition of small strain, firstly, the secant shear modulus was always larger than the tangent shear modulus. Secondly, when the logarithmic coordinates were applied to describe shear strain, the decrease of shear modulus with shear strain could be expressed by reversed S shape curve with two inflexion points, and through analyzing and validating, the deduced equation could perfectly reflect this characteristic. Finally, different stress paths and strain areas would lead to different attenuation trends.

而且，在小应变范围内，割线剪切模量总是大于切线剪切模量；当剪切应变采用对数坐标表示时，剪切模量随着剪切应变的增加而衰减，且衰减的规律都可以表示为带有两个拐点的反S型曲线，经分析验证本文所得公式3可以对此特性进行很好地反映；但应力路径、应变范围不同其衰减幅度不同。

For the low linear saturation threshold of photoelectric detector,a new and reliable method used in diagnostic system is introduced to attenuate high energy laser power density using multilayer dielectric coating.

针对环形光刀取样式高能激光束在线测量系统应用中光电探测器线性饱和功率密度低而被测高能激光功率密度高的特点，采用对取样激光扩束和介质膜衰减片级联衰减的方式，实现了数千倍的线性光强衰减。

Based on the analysis of absorption characteristic of desensitizing dye the free photoelectron decay curves of desensitized silver chloride emulsion exposed by 532nm are measured by microwave absorption and dielectric spectrum detection technology.

在对减感染料的吸收特性进行分析的基础之上，利用微波吸收介电谱检测技术测量了减感后氯化银乳剂在532nm波长曝光下的光电子衰减曲线，通过分析减感染料对光电子强度和衰减的影响，发现在光谱增感波段减感染料通过与增感染料相互竞争的吸(来源：A17B7464C论文网www.abclunwen.com)收光而影响光谱增感乳剂的光电子强度，并且减感染料通过俘获光电子使光谱增感乳剂的光电子的衰减变快。

Then we discuss the loss model of the tellurite glass and try to give a practicable way to reduce the loss of the fiber.

根据衰减理论模型分析了碲酸盐玻璃光纤的衰减和降低衰减的途径或方法。

In order to obtain the environmental vibration's characteristics of attenuation with distance and that of frequency in test study, a good many of tests is carried out on propagation and attenuation of environmental vibration for typical zone of the Pearl Line.

在实测研究方面，为得到高架轨道交通引起环境振动的距离衰减规律以及振动衰减的频率特性等，针对上海市明珠线高架轨道交通的典型线路区段，进行了大量环境振动实测及其传播和衰减规律研究。

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。