异构的

Configurational isomerism is then due to the presence in the molecule of one or more dissymmetric centres ,in the simplest case asymmetric carbon atoms ,each of which can have and absolute configuration; and ,or ,to the presence of double blonds which can give cis- and trans-geometrical isomers .

构型异构是由于分子中存在一个或一个以上的不对称中心，在最简单的情况下是不对称碳原子，每个不对称碳原子的绝对构型是和；或者，如果存在双键的话，那么将给出顺式和反式几何异构体。

Implemented using layered heterogeneous data integrating algorithm whichbased on IP-SAN in digitized aircraft design For the advantages of IP-SAN, we provided a heterogeneous data integratingalgrithem which took IP-SAN as data center and based on layered meaning,implemented the heterogeneous data integrating system in digitized aircraft designengineer, on the basis of showing the digram of the system, we described the systemintegrating layers and characteristic.

七、提出并实现了基于IP-SAN的分层异构数据集成算法在飞机设计数字化中的应用基于IP-SAN所具有的诸多优势，提出了以IP-SAN形成数据中心，基于对象层次思想的异构数据库集成算法，实现了飞机设计数字化工程中的异构数据库集成系统，在给出系统体系框架图的基础上，描述了系统集成层次结构及特点。

The results indicate that thermal stabilities and decomposition mechanisms of the title compounds derived from the BDE, Ea and static electronic parameters are basically consistent. Homolysis of the N—NO2 bond is the initial step in the thermolysis of the title compounds, the meta-isomers are more stable than the para-isomers, and the ortho-isomers are the most sensitive.

结果表明，由BDE、Ea和静态电子结构参数推断的标题物热稳定性和热解机理的结论基本是一致的，N-NO2键均裂是标题物的热解引发步骤，间位取代异构体较对位取代异构体稳定，而邻位取代的异构体稳定性最差。

Hydrocyanic acid and water proceed via a five-centred transition states then transformed by its exterior hydrogen-bond; The results show that the activation energy of the isomerizing reaction in the aqueous phase is lower than that in the gas phase. It is likely that the hydrogen bonds formed in the complexes and the solvent effect play an important role.

计算结果表明，在水相中异构化过程的活化能比在气相中低，无论在气相还是在水相中异氢氰酸通过水氢键转化成氢氰酸容易些，而氢氰酸由水氢键转化成异氢氰酸相对要困难些，分子间氢键和溶剂化效应在异构化反应过程中起到重要的作用。

But it is very difficult to design and implement query optimization because of the distribution and heterogeneity of the computing environment and the autonomy of multiple local data sources.

查询优化是异构数据集成中需要解决的关键问题之一，但环境的分布性、异构性以及局部数据源的自治性使得异构数据集成中的查询优化变得非常困难。

The ground-state structures of 8 tautomers of cytosine were fully optimized at B3LYP/6-311+G(superscript **) level, and the tautomerism of 6 relatively stable tautomers of cytosine was studied.

用该方法对胞嘧啶分子的8种异构体构型进行了充分优化，研究了其中能量较低的6种胞嘧啶异构体的互变异构化过程。

A computational result of RHF/LANL2DZ optimized structure and total energy shows that the isomers with C H…π structure have lower total energy, and that stability and isomeric preference of isomer are related to the C H…π interaction in the isomer.

用 RHF/LANL2DZ对该体系可能的异构体进行结构、能量优化，可能形成C—H…π相互作用的异构体具有较好的稳定性。C—H…π相互作用对含吡啶环的[CoN5Cl]^2+系配合物的异构体的选择性形成及其稳定性具有重要作用。

In the 29 Aroma material studied, the content of the material having important effect such as norambreinolide, octadecanoic lactone(1), octadecanoic lactone(2), octadecanoic, 8,15-labdanum-1-ol,8,12-external oxidative labdanum-14-en-2-ol(1), 8,12-external oxidative labdanum-14-en-2-ol(2), 8,13-external oxidative labdanum-14-en-13-one(1), 8,13-external oxidative labdanum-14-en-13-one(2) Dihydroactinidiolide, solanone, norsolanone have Significant increasing trend in the aging, the peak of the content of material appear in the 18~21 months in the aging process.

在所测定的29种香气物质中，对香料烟特征香气有重要影响的香味物质如降龙涎香内酯、硬尾内酯2种异构体、硬尾醛、8，15－赖百当醇、2种8，13外氧赖百当－14－烯－13醇异构体和2种8，13外氧赖百当－14－烯－13－酮异构体，二氢猕猴桃内酯、茄酮和降茄二酮等成分在陈化过程中有明显的增加，总的香气物质含量变化的高峰期出现在陈化18~21个月。

The invention includes all sterioisomeric forms, including individual diastereoisomers and enantiomers of the compound of formula as well as racemic and non-racemic mixtures thereof.

本发明包括式化合物所有的立体异构形式，包括单个的非对映异构体和对映异构体，及其外消旋的和非外消旋的混合物。

Comparisons between the experimental and computational IR spectra clarify the difference of the open- and closed-ring isomers, which indicate that it is possible to identify the tautomeric form of this diarylethene derivative using a highly selective infrared absorption band and the strong absorption at 1 705 cm-1 of the ring-closed isomer can be used in non-destructive readout by IR light.

通过红外吸收光谱表征了该光致变色二芳基乙烯衍生物在溶液中开、关环前后结构的变化，并采用理论化学计算方法研究了该化合物开、关环异构体的红外吸收振动特性。光致变色异构化过程可以通过红外吸收光谱的变化而识别。关环异构体在1 705 cm

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。