查询词典 isomers

Write the structural formula for an alkyne hydrocarbon having the fewest number of C's, which has geometric isomers, and give the IUPAC name for both geometric isomers.

答：写出有几何异构体的，含碳原子数最少的炔烃的结构式，并对所有的异构体用IUPAC命名法命名

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。

Complex 4 exists as a mixture of two isomers. The interconversion between the two isomers was studied by variable-temperature 1H NMR.

化合物4存在两种异构体，通过变温核磁研究了这两种异构体的相互转化。

Those that rotate light in the opposite direction are called levorotatory or optical isomers. The symbols d- and l-, formerly used to indicate dextro- and levorotatory isomers, are no longer sanctioned owing to confusion with D- and L-, which refer to configuration relative to D-glyceraldehyde.

其符号d-和 l-，原先是用来表示右旋的和左旋的异构体，现在由于容易与D-和L-混淆而不再使用，这两个符号涉及与D-甘油醛相关的结构）。

In experimental research, the S-L-E of three groups of isomers was determined by using differential scanning calorimetry , and more than two hundred reliable data were obtained. The isomers include meta-, ortho-, and paradichlorobenzene, meta-, ortho-, and para-dibromobenzene and meta-, ortho-, and para-nitro-benzoic acid.

在实验的研究中，采用差式扫描量热测定了邻、间、对二氯苯，邻、间、对二溴苯及邻、间、对硝基苯甲酸等三组同分异构体物系的固液相平衡关系，共得到二百多个可靠的数据。

Such as pentane there are three isomers, Wang alkyl has 35, while containing 30 carbon atoms, the number of isomers of alkanes up to 411 × 109 Ge.

例如戊烷的异构体有3个，王烷有35个，而含30个碳原子的烷烃的异构体数目高达411×109个。

The hydrogen bonding of 1:1 complexes formed between acetamide and three kinds of isomers of picolines have been completely investigated using B3LYP method at various basis set levels from 6-31G to 6-31+G and 6-31++G. The results show that the interaction energies of hydrogen bond complexes between acetamide and picoline isomers have great effects on the values of h_.

2采用密度泛函理论等方法研究了乙酰胺分子分别与甲基吡啶三种异构体分子以1：1的比例形成的氢键络合物，从B3LYP/6-31G到6-31++G基组水平进行了优化，利用结合能数据讨论了焓对作用系数的差异。

The structure and stability of all possible isomers of C50X(X=SiH2, PH, S) were investigated by ab initio HF/3-21G calculations. The calculation results indicate that the preferred position for cycloaddition of SiH2, PH, and S on C50 is consistent, i.e. on the C3-C4 and C4-C4 sites of C50, and the resultant most stable cycloaddition isomers are [5,6]-closed and [5,5]-closed structures. The main driving force governing the stability of the C50X(X=SiH2, PH, S) isomers is the strain, or the conjugative effect, or the combination of strain and conjugative effect, depending on the addition positions and the types of the attacked C-C bonds.

用从头算HF/3-21G方法研究了C50的环加成衍生物C50X(X=SiH2， PH， S)所有可能的异构体的结构与稳定性，计算结果表明，SiH2基团、PH基团与S原子在C50上环加成的优先加成位置相同，都为C3-C4类键和C4-C4类键，并且相应形成[5，6]-闭环和[5，5]-闭环结构的最稳定异构体；决定C50X(X=SiH2，PH，S)各异构体稳定性的主要因素，因加成位置以及发生加成反应的C-C键的单双键类型的不同，可能是张力、共轭效应或者二者的共同作用。

Rresults from those studies can be summariazed as follow:(1) A preliminary study no correlationship between the UV-VIS reflection spectrum of tomato fruit surface and the lycopene amount of tomato fruit was undertaken. Based on observation from this study, a damage-free and in-situ detection technique of lycopene amount from tomato was developed with UV-VIS reflection spectroscopy;(2) The geometrical isomers of lycopene were separated successfully on C30-HPLC-PDA-ELSD. The absorption coefficients of Z-isomers were consequently dedermined. The geometrical isomer composition of lycopene could therefore be assessed. Those efforts formed a solid base to identify the natural product from synthetic compound of lycopene;(3) Lycopene resource from the fruit of Autumn oliver was proved to be available for industrial application. An extraction methos of lycopene from the fruit of Autumn oliver by supercritical carbon dioxide was developed at laboratory scale;(4) A method to extract lycopene by supercritical liquid with improved efficiency was developed; Data from this investigation suggested that a proper raw material pre-extraction process was important for a better extraction efficiency;(5) Variation in the geometrical isomer composition of lycopene during its metabolish in rat was assessed. A large amount of Z-isomers were observed. This variation took place in serum;(6) The absorption rate and accumulation in serum of natural lycopene in rat were assessed;(7) Ability to quench singlet oxygen by different geometrical isomers of lycopene was compared;(8) It was detected that whether natural lycopene had functions to regule blood-lipids and LDL antioxidation;(9) A C31 degradation piece of lycopene was found in the prostate gland of rat.

研究结果包括：[1]应用UV-VIS反射光谱法建立了番茄果实中番茄红素含量的无损伤、现场检测技术；[2]应用C30-HPLC-PDA-ELSD技术实现了对番茄红素几何异构体的分离，测定了不同顺式异构体的吸光系数，建立了天然番茄红素几何异构体组成的检测方法，为区分和鉴定人工合成品和天然产物奠定了基础；[3]证实了秋橄榄果实中的番茄红素资源具有工业开发价值，并建立了超临界CO_2萃取的实验室方法；[4]探索了提高番茄红素超临界流体萃取效率的方法，证明了物料前处理对提高萃取效率起了极其重要的作用；[5]观察了番茄红素在大鼠体内几何异构体组成的变化情况，发现了大量顺式异构体的存在，并证实了几何异构体组成在血清中发生了显著变化；[6]测定了天然番茄红素在大鼠体内的吸收率和在大鼠血清中的动态积累规律；[7]比较了不同番茄红素几何异构体淬灭单线态氧的能力；[8]检测了天然番茄红素是否具有调节血脂作用和抗低密度脂蛋白氧化的功能；[9]首次发现大鼠前列腺内存在番茄红素C31降解片段，并证实其仍具有淬灭单线态氧的能力。

The calculated NICS values show that nucleus-independent chemical shifts values of roof-shaped isomers for Sb42-, Bi42-, and22- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters.

计算显示Sb42-、Bi42-和22-团簇的所有屋顶型结构的核独立化学位移全部为负值，从而说明这些屋顶型结构拥有芳香性；平面环结构的核独立化学位移值全部为正值，说明这三种平面环结构具有反芳香性。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。