变化系数

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

Through assessment, it can be concluded that the water quality in Shuimo river valley of Urumqi was worse; the water quality did not improve in last three years, and this trend was not stable either in space or in time; the water quality was best in low water period but it's worse in flush water period and slack water period; in space the water quality in Tangcichangquan section was best , it's the second place in Qifangqiao section and Lianfengqiao section while it's worst in Miquanqiao section. According to the analysis, the trend of the water quality change of Shuimo river valley of the major pollutants, the method of Spearman was used in 1996 to 2002. It concluded, the pollutants did not have the remarkable trend of change in Tangcichangquan section,but BOD5 had very prominent raising trend in Qifangqiao section, so did BOD5, petroleum, and ammoniac nitrogen in Lianfengqiao, DO in Miquanqiao section in seven years.

根据秩相关系数法对水磨河流域1996 -2002 年主要污染物变化趋势分析，搪瓷厂泉断面作为流域的源头，各污染物七年里没有显著的上升或下降趋势；七纺桥断面的五日生化需氧量在七年中有很显著的升高趋势；联丰桥断面的五日生化需氧量、氨氮、石油类在七年里都有非常显著的升高趋势； DO 在米泉桥断面七年里也有非常显著的升高趋势，后三个断面接受了沿岸工矿企业的生产废水和周边居民的生活污水，水质明显变差，每个断面污染源不同，占主导地位的污染物也有差异。

In order to investigate the physical attack of different crystal products of sodium sulfate solution including Na2SO4 ments were carried out by partial soaking with 150 g/L sodium sulfate solution and an index was introduced to evaluate the resistance of mortar to physical attack of sodium sulfate solution.

采用150 g/L的硫酸钠溶液半浸泡的试验方法，以砂浆抗蚀系数为指标，研究了相对湿度和温度变化条件下，硫酸钠溶液的不同结晶产物Na2SO4与Na2SO4·10H2O对砂浆试件的物理侵蚀作用和不同条件下硫酸钠溶液的物理侵蚀特性及相关机理。

Then draws the conclusion:The Xi'an commercial real estate change of price's influencing factor is in turn commercial business completes the investment cost,the social fixed assets investment,the urbanized level,the resident consumption price index,the township dwellers according to influence size sorting with the room to be possible to control the income,the average per person family consumption gross charge,the vacant area,the Engel's coefficient,the population density.

进而得出结论：西安市商业地产价格变化的影响因素按影响力大小排序依次是商业营业用房完成投资额、社会固定资产投资、城市化水平、居民消费价格指数、城镇居民可支配收入、人均家庭消费性总支出、空置面积、恩格尔系数、人口密度。

To define the spatial distribution pattern of point objects, a new approach is introduced, which employs the variation coefficient CV of the area of Voronoi polygons.

：点集的Voronoi图是对点集的一种空间分割方式，不同分布的点集可以形成Voronoi多边形面积的不同变化，可以通过计算点状目标的Voronoi多边形面积的变异系数方法，来分析点状目标的空间分布特征。

The results show that CO2 specific heat, density, thermal conductivity and viscosity vary abruptly near the pseudocritical temperature.

结果表明，CO2的比热、密度、导热系数以及粘度在准临界点附近的变化非常剧烈。

Due to the difference of heat conduction coefficient, specific heat capacity and expansion coefficient between concrete and rock, under cyclic variation of temperature, the junction plane is liable to crack in the slope supported by shotcrete.

由于混凝土材料与岩土材料的热传导系数、比热容与热膨胀系数的差异，在温度的循环变化下使得喷射混凝土边坡容易于喷层与岩土层的结合面处产生应力集中而开裂。

Fourthly, it discusses the spectral image loss-less compression by applying thecorrelation and the entropy of the spectral image sequence. It gives and analyses three expressions of imaging spectrometer images, and tells the change in correlation coefficient and entropy for different expressions. At last, it puts forward D2PCM de-correlation method to reduce the spatial and spectral redundancy. This method improves the compression ratio and the compression efficiency, being easy and fast in operation.

根据成像光谱图像的空间、谱间相关性和信息熵的特征，提出成像光谱图像序列的三种表示方法，分析了不同表示方法的相关系数和图像信息熵的变化，并研究出了成像光谱图像的无损压缩方法，即利用D~2PCM方法对光谱图像序列进行去相关处理，同时降低图像的空间和谱间冗余，在提高了无损压缩的压缩比和压缩效率的同时，算法具有简单快速的优点。

Fourthly, it discusses the spectral image loss-less compression by applying thecorrelation and the entropy of the spectral image sequence. It gives and analyses three expressions of imaging spectrometer images, and tells the change in correlation coefficient and entropy for different expressions. At last, it puts forward D2PCM de-correlation method to reduce the spatial and spectral redundancy.

根据成像光谱图像的空间、谱间相关性和信息熵的特征，提出成像光谱图像序列的三种表示方法，分析了不同表示方法的相关系数和图像信息熵的变化，并研究出了成像光谱图像的无损压缩方法，即利用D~2PCM方法对光谱图像序列进行去相关处理，同时降低图像的空间和谱间冗余，在提高了无损压缩的压缩比和压缩效率的同时，算法具有简单快速的优点。

The correlation coefficient stationary process in which the mean and variance vary with time is familiar in engineering,and the traditional correlation function stationary process is just a special case of that.

相关系数平稳过程是从非平稳过程中分离出的一类工程上常见且便于研究的随机过程，其均值和方差都可随时间变化，传统的平稳随机过程是它的一个特例。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。