衰减系数

The analysis of the continuous property of raw silk size Setting the decaying rateλand the quasi-cycle value T in the model of the silk size autocorrelation coefficient, building the time series of a single cocoon reeling silk size with autoregressive model, then by combining k such time series according to different phrase, obtained time series of the raw silk size, and finally count up the silk size deviation of the time series.

利用一理想化的正弦波模型生成一粒缫生丝纤度时间序列，通过调查该模型中波动幅度及波动周期的变化对自相关系数序列衰减率的影响，初步建立起一粒缫生丝纤度自相关系数列衰减率λ与纤度时间序列特征数之间的关系式。从而使我们可以生成具有要求连续性特征的生丝纤度时间序列，为进一步研究生丝纤度连续性特征提供了新的途径。

In some materials with periodic variation of dielectric constants and light within a certain frequency range shows exponential decay due to destructive interference and cannot propagate. This phenomenon is called photonic bandgap and this kind of structures is called photonic crystals.

介电系数周期性排列的材料，部分波段会因破坏性干涉呈指数衰减，导致无法在此结构上传播，此现象称为光子能隙，此类具有介电系数周期性排列的结构则称为光子晶体。

According to the feature of the SARS Chest Radiographic Images, the wavelet analysis method is put forward to dispose the SARS images and the wavelet coefficients are picked up. After the wavelet threshold noise reducing and the wavelet threshold enhancing disposure to the each of the wavelet coefficients, the clear images are reconstructed at last.

摘 要：通过对非典型肺炎的胸部 X 线图像的特征分析，提出采用小波分析方法，对图像做小波变换，提取各层小波分解系数，利用阈值法对各系数作去噪预处理，然后再利用阈值法对各系数做衰减或增强处理，最后重构出清晰图像。

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。

Main contents and conclusions are: 1 The ionization current was measured continuously by a charge-integration method with a computer after the introduction of radon into the chamber.

主要内容及结论：1充氡后利用计算机连续进行电离电流累积测量，得到了精细的电流随时间的变化曲线，可清楚看出氡及其子体的生成衰变造成的电离电流的生长—稳定—衰减过程，与理论计算值进行了比较，由电离电流衰减速度的变化得出氡吸附作用的影响，并测量到电离室冲洗后氡的反扩散现象；2由已知活度的标准源定出相对测量的刻度系数K值，K=24.62 Bq／pA，对同一个监测源以半年为周期进行多次测量后得出稳定性符合要求；3通过测量电离电流和气压的关系曲线以及不同气压下的饱和曲线，确定了常规的工作条件；4测量了盐酸清洗电离室内表面降低本底的效果；5不确定度分析表明相对测氡的扩展不确定度(k=2)小于5％，由本底涨落得出探测下限为0.5 Bq；6理论上对壁损失修正进行了计算，实验上保持电离室工作在饱和区的情况下，测量了不同气压下电离电流的变化，从中得出了壁损失随气压变化的规律，可以看出，电离电流的实测值和计算值随气压变化规律基本一致；当气压大于125 kPa时，端效应等其它因素造成的影响不大于2％，因而在此工作条件下，测量电离电流后通过计算修正壁损失可以实现近似的绝对测氡，提出了进一步提高绝对测量准确度的方法。

Then the MEMS solenoid type electromagnetic actuating and novel, frictionless and wear-free, and simple structure are designed for fiber-deflecting type MEMS VOA: One of the two coupled single mode fibers is completely fastened in one of the three aligned U-shaped grooves while the deflectable fiber is partially fixed in another groove with a long front section suspending over the wider groove as a cantilever beam. The two fibers, any one for input and the other for output, are well aligned initially so that the insertion loss is very low. Beside the deflectable fiber is a solenoid microactuator with a U-shaped permalloy core attracting a permalloy piece glued on side of the fiber cantilever so that the fiber is deflected and the optical power coupled between the fibers decreased continuously. Using MEMS solenoid as a continuous actuator and the novel structure of VOA are not seen in literature.

为光纤偏移型MEMS可变光衰减器设计了MEMS螺线管电磁驱动方式以及新颖的避免了静摩擦、磨损而且简单的整体结构形式：在硅基片的三段V形槽结构中，将两个对接单模光纤之一完全固定在基片上，只将另一根光纤的稍后部位固定于基片上而使其前端的一定长度悬空，形成一个悬臂梁结构；初始对准后两根光纤之间的光传输损耗很小；通过U型铁芯MEMS螺线管吸引固定于光纤悬臂梁上的坡莫合金片，驱动光纤悬臂梁连续偏移以使两根光纤之间功率传输系数连续变化，从而达到光功率连续衰减的目的。

As an often used physical model with good theoretical and practical values, StreeterPhelps model has been widely used to study water quality. However, in some special water areas the utilitization of StreeterPhelps model has some limitation as confirming reaeration coefficient often comes from tests in rivers with fast water flow speed with no consideration of wave effects. Furthermore, in practical research in Three Gorges Reservoir, the changing rule of COD appears abnormally. In some water areas far from pollution source, the value of COD changes with time, but does not follow the exponential attenuation rule. This phenomenon can not be explained by former modified StreeterPhelps model.

StreeterPhelps模型是目前进行河流水质研究常用的物理模型，具有良好的理论和实用价值，然而在某些特定水域，该模型的应用受到限制，主要原因是复氧系数的取定多在水流速度较大情况下得到的，而未考虑水面波动对复氧系数的影响，另外，在实际研究过程中发现三峡库区COD变化的规律出现异常：在离排污口相当远的水域，COD随时间变化趋势并不是指数衰减，而是在某个常值附近微小摆动，以往很多修正过的StreeterPhelps模型都无法解释这个现象。

In order to probe the absorb coefficients of earth medium by the direct wave, reflected wave and transmied wave amplititude which are picked up from the radar wave racords yielded by finite element method,the paper gives out the attenuated radar wave equations in time domain and the attenuated radar wave differential equations while the motion changes simple harmonic with time and electric parametets change slowly with space.

摘 要 为了用有限元方法生成雷波正演记录，从而拾取直达波、反射波、透射波振幅信息，以确定介质吸收系数，文章在时间域给出了雷达波含衰减项的波动方程，及在运动随时间简谐变化以及电性参数随空间缓变的条件含衰减项的雷达波遵循的简化微分方程。

Compared with the common wavelet by the Fourier transform, the decay of weighted wavelet coefficient is faster than that of the common wavelet. Furthermore, the method is simple and easily applied. Its computational complexity is greatly reduced.

与采用常见的Fourier变换得到的正交小波相比，加权小波系数的衰减性比正交小波的系数衰减性快，而且计算过程简单，复杂度低，易于应用。

Through discussing further the reflective and refractive coefficients of line boundary, the features of line boundary are as follows: the attenuation of high frequency band (especially in band of line trap) of transient components generated by fault through line boundary is obvious, whereas the low frequency band (1~10kHz) components are hardly influenced. Moreover, the transient components below 100kHz should be adopted in purpose of outstanding the line boundary and weakening the transmission influence of transmission line.

通过对线路边界的透、反射系数的进一步分析发现：暂态信号的高频段穿越线路边界时将大为衰减，而低频段(1~10kHz)几乎不衰减；为弱化线路的传输影响而突出线路边界的作用，宜选用100kHz以下的信号分量。

Lugalbanda was a god and shepherd king of Uruk where he was worshipped for over a thousand years.

Lugalbanda 是神和被崇拜了一千年多 Uruk古埃及喜克索王朝国王。

I am coming just now,' and went on perfuming himself with Hunut, then he came and sat.

我来只是现在，'歼灭战perfuming自己与胡努特，那麼，他来到和SAT 。