异构体

IR, UV-Vis, 1H NMR The IR, UV-Vis and 1H NMR of selenadiazoles were investigated. Their IR peaks were classified as the corresponding groups or bonds; The relation of their structure with the conjugative effects, absorbtion wavelength and molar absorb coefficients were discussed with the UV-Vis. The value of selenadiazoles in analytical chemistry and the varieties of structure with the pH were discussed.

IR，UV-Vis，~1H NMR 对硒二唑类化合物的IR吸收峰进行了归类与指认，讨论了SPO、SPDO的异构体的分子结构；探讨了UV-Vis、吸收波长和摩尔吸光系数与分子结构的相对应关系，以及紫外吸收光谱性质在分析化学上的应用价值和溶液的pH值引起SPO、SPDO的结构变化。

The major products were methane, ethylene, propylene, butylene, butadiene, cyclopentadiene, benzene, toluene, styrene, vinyl-substituted cyclopentene derivatives and C5/C6 isomers (pentadiene, methyl-substituted cyclopentene derivatives, cyclohexene, hexadiene and methyl-substituted cyclopentadiene derivatives), and the main primary products were determined to be C1～C4 compounds, cyclopentadiene, benzene, toluene and vinyl-substituted cyclopentene derivatives.

热裂解主要产物为甲烷、乙烯、丙烯、丁烯、丁二烯、环戊二烯、苯、甲苯、苯乙烯、环戊烯的乙烯基取代物及C5， C6异构体(戊二烯、环戊烯的甲基取代物、环己烯、己二烯和环戊二烯甲基取代物)，其中， C1～C4、环戊二烯、苯、甲苯、乙烯基取代环戊烯为初始产物。

The major products were methane, ethylene, propylene, butylene, butadiene, cyclopentadiene, benzene, toluene, styrene, vinyl-substituted cyclopentene derivatives and C5/C6 isomers pentadiene, met...

热裂解主要产物为甲烷、乙烯、丙烯、丁烯、丁二烯、环戊二烯、苯、甲苯、苯乙烯、环戊烯的乙烯基取代物及C5，C6异构体(戊二烯、环戊烯的甲基取代物、环己烯、己二烯和环戊二烯甲基取代物)，其中，C1～C4、环戊二烯、苯、甲苯、乙烯基取代环戊烯为初始产物。

The first asymmetric total synthesis of coumarinolignoids Daphneticin and it's enantiomer was accomplished starting from 7-hydroxycoumarin and 3, 4, 5-trimethoxybenzaldehyde, in which Sharpless asymmetric dihydroxy reaction was used to construct chiral center, and Mitsunobu reaction was used to obtain desired configuration.

并以7-羟基香豆素和3，4，5-三甲氧基苯甲醛为起始原料，用Sharpless不对称双羟化反应构筑手性中心，用Mitsunobu偶联反应作为关键步骤，合成了手性的香豆素木脂素Daphneticin及其异构体。

For a disubstituted complex, MA4B2, the planar arrangement gives three isomers, the familiar ortho, meta, and para arrangement s of organic chemistry.

对于双取代络合物MA4B2，其平面排列有三个异构体，常见的为有机化学中的邻位、间位和对位排列。

For a disubstituted complex, MA4B2, the planar arrangement gives three isomers, the familiar ortho, meta, and para arrangements of organic chemistry.

对于双取代络合物 MA4B2，其平面排列有三个异构体，常见的为有机化学中的邻位、间位和对位排列。

Given the heats of hydrogenation below for isomers A and B, would you say that an exocyclic double bond or an endocyclic one is more stable

答：给出了互为同分异构体的A和B的氢化值，你能否说出环外的双键和环内的双键哪一个更稳定吗

The equilibrious geometries and electronic structures of possible isomers of Si4N4 clusters are studied by using density functional theorywith basis sets 6-31G*.17 possible isomers are obtained.

用密度泛函理论中的杂化密度泛函B3LYP方法，在6-31G的水平上对Si4N4团簇的可能结构进行了几何结构优化和电子结构计算，得到了可能的17个异构体。

Our observations suggest that, in addition to motility, the protein phosphatase PP1 gamma 2 might play an isoform-specific function in the development of specialized flagellar structures of mammalian spermatozoa.

我们的观察表明运动性蛋白磷酸酶PP1γ2可能在哺乳动物精子的鞭毛的特异结构的发育过程中具有异构体特异的功能。

Among them,the chemosensory properties of two molecular tweezers derived from diethoxycarbonyl glycoluril for metal ions were studied by fluorescent spectroscope.It was found that they both exhibited selective recognition towards Fe~(3+)among 13 metal ions investigated in DMF/CH_3OH(50:1, v/v)with fluorescence quenching,and formed 1:1 stoichiometry complex with Fe~(3+).

通过荧光光谱滴定考察了其中两个二乙基酯基甘脲分子钳异构体对13种不同金属离子的识别作用，研究表明在DMF/MeOH(50：1 v/v)中，它们能够很好地选择性地识别Fe~(3+)离子，与Fe~(3+)离子形成1：1的复合物并且呈现荧光淬灭效应，可作为Fe~(3+)的荧光化学传感器。

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