成分

Two polysiloxanes (SR2 and P67) and one polycarbosilane were chosen as preceramic polymers. TG-DTA-MS, FT-IR, XRD,〓Si MAS-NMR, SEM, TEM, SAD, HREM, chemical analysis and density measurement techniques were used to study the cross-linking and pyrolysis mechanisms of the preceramic polymers. The development of chemical composition and structure, density, phase composition and microstructure of the solid pyrolyzed products during pyrolysis process were systematically investigated. While pyrolysis temperature approached 1000℃, ceramization process of the preceramic polymers almost completed, and ceramic yield of the preceramic polymers hardly changed any more.

选取了两种聚硅氧烷（SR2和P67）和一种聚碳硅烷作为聚合物先驱体，利用TG-DTA-MS、FT-IR、XRD、〓SiMAS-NMR、SEM、TEM、SAD、HREM以及化学成分分析、密度测量等手段，研究了聚合物先驱体的固化机理；以N〓为热解气氛，系统地考察了各种聚合物先驱体在热解过程中，其热解产物的化学成分和结构、密度、相组成及显微结构的演变规律。

Nitrogen is the other primary component of air at 78%, with other trace components totaling approximately1%.

氮是空气的另一个主要成分，占78%，其它微量成分总共占大约1%。

The paper expounds the feature of the two kind of method, especially the virtue,principles and calculating stages of the primary component analysis within the Objective weight defining method.

文章讨论了两类不同的评价方法的各自特点，并重点论述了客观赋权法中的主成分分析法的优点及原理，归纳整理出了主成分分析法的计算步骤。

We can infer that contrived factor is distinct contribution from the four extracted prime components. The contributing rate in the first prime component is 54.4%.

从提取出的四个主成分看出，人为作用对荒漠化有显著的贡献，第一主成分中变量的贡献率是54.4％。

Keywords: image analysis, principal curves, principal curve component, neural network

仿真实验结果表明，主曲线成分分析能很好地解决非线性主成分问题，应用前景广阔。

Consideration on the basic value of corporation, market value and behavioral value integrally, it chooses indexes, filter indexes with principal component method, distills principal factors, builds up pricing model under seeking system, and checks up the application effect of model, so that it proves that pricing model importing the behavioral factors is more availability than the models before.

在综合考虑公司基本价值、宏观市场价值、心理行为价值三方面因素的基础上，选取指标，运用主成分分析法筛选指标，提取主成分因子，建立了询价制度下的新股定价模型，并对模型的应用效果进行了检验，证实了引入心理因素的定价模型要比以往的定价模型更有效。

The method uses techniques such as document space transforming and principal component analysis to map original document vector in very-high-dimension term space to low-dimension principal component space, and then categorizes documents by comparing them to the centroid of each category.

该方法采用了文档空间变换和主成分分析技术，将文档的原始矢量表示从高维词条空间映射到低维主成分空间，并利用文档类别重心进行分类。

The multivariate analysis for structure simplification includes principal component analysis, principal component factor analysis and maximum likelihood factor analysis.

为简化形態性状多样性结构所进行之多变数统计分析包括主成分分析、主成分因子分析及最大可能率因子分析。

This paper proposes an efficient clustering algorithm for Multivariate Time Series—PCA-CLUSTER.The algorithm applies principal component analysis to reduce the dimension of MTS,and subsequently chooses the principal component series of MTS to cluster by a K-nearest neighbor algorithm.

提出一种高效的多变量时间序列聚类算法PCA-CLUSTER，首先利用主成分分析对MTS数据降维；选取MTS数据的主成分序列进行K近邻聚类分析。

On the basis of the Principal Component Analysis method this novel has analyses the parameter which influenced the weapon expenses ,got the principal component variable of the weapon expenses parameter model and preferably reflected the actual conditions of the weapon.

文中基于主成分分析方法，对影响武器费用的参数进行了分析，得到了武器费用参数模型的主成分变量，较好地反映了武器的实际情况，最后给出了模型的一个应用实例。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。