异态性

And the evaluation effects of China's Stock Market's volatility by different ARCH models from different point of view are compared. In addition, by using two mixed distribution models, the leptokurtosis and fat-tail of stock return are examined. Based on the above analysis, an improved Laplace distribution model is proposed. Furthermore, the root generating non-Gaussian return distribution of the stock market ? is expounded from the perspective of both economy and capital market.

首先分别从分布和波动性模型出发，研究中国股票市场收益分布特征与波动性特征：从ARCH族模型出发，考察了中国股票市场波动性的异方差、集群性、杠杆效应以及长记忆性特征；从两个混合分布模型出发，结合随机模拟考察了收益分布的尖峰、厚尾和偏态特征，并提出了改进型LapJace分布。

The establishment and relaxation processes of the transient gratings, which are formed by two recording 514nm beams with different polarization directions, SS, PP, SP and ±45℃, are investigated. Using the weak absorption of the chromophores at 632. 8nm and the positive dichroism of the chromophores molecules, a kind of bi-photonic transient gratings, owing to the periodic distribution of Trans and Cis isomers, is established first time in azo-dye doped polymeric bulk sample.

实验考察了两束514nm的写入光在不同偏振情况下（SS，PP，SP和±45），在样品中形成的瞬态栅的建立和弛豫情况；利用偶氮生色团在632.8nm波段的微弱吸收和生色团分子的正二向色性，首次在块状偶氮聚合物材料中形成一种基于生色团反式和顺式异构体密度分布的双色光瞬态栅；利用瞬态栅的快速建立和弛豫，考察了其在衍射型全光开关方面的潜在应用。

Rep-PCR method was used to conduct cluster analysis to the 39 bacterial isolates. rep-PCR analysis revealed that the 39 bacterial isolates could be divided into 12 clusters at the 0.9 dissimilarity percentage level. The 39 bacterial isolates had their own specific band patterns, showing obvious genomic heterogenicity and rich genotypic polymorphism genetic diversity between each isolate.

采用rep-PCR技术对39个细菌分离株进行聚类分析，在rep-PCR图谱的相异百分数为0.9的水平上被聚类为12个类群，39个分离株各自具有独特的带型，说明各细菌分离株的基因组之间存在显著异质性，表现出丰富的基因型多态性。

Three organochlorine pesticides -endrin, dieldrin, and p,p'-DDT-were used as target compounds to test the hypothesis that triolein embedded cellulose acetate membrane only extracts freely dissolved hydrophobic organic compounds. The effect of dissolved organic carbon on the bioavailability of the OCPs was also examined through accumulation study with TECAM and Japanese medaka.

以异狄氏剂、狄氏剂和p，p'-滴滴涕3种持久性有机氯农药为研究对象，通过室内模拟实验，验证了三油酸甘油脂-醋酸纤维素复合膜富集水中自由溶解态疏水性有机物的假设，研究了水中溶解性有机碳对TECAM富集3种有机氯农药的影响，并与相同暴露条件下日本青鳉鱼的富集结果进行了比较。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐