取代的

The results also show that subtituent position on the benzene ring has a great influence on the transfer volume. The trends of change of δ〓ΔΦ〓〓 for mand p-isometers with the composition of the mixed solvent are similar. However, the position and amplitude of the limit valve are different from each other. These are discussed according to the inductive effect and the resonance effect.

研究发现：取代基在苯环上的取代位置对迁移偏摩尔体积有明显影响，间、对位取代的异构体在DMF-水混合溶剂中的δ〓Δφ〓〓随混合溶剂的组成变化规律相似，但极值点的位置及幅度有所不同，根据诱导效应和共轭效应对此进行了讨论。

We have studied the transition metal complexes catalyzed sequential cross coupling reactions of these new difunctional group reagents with electrophiles and nucleophiles, respectively; developed some convenient and practical new methods for the stereoselective synthesis of disubstituted alkenes, trisubstituted alkenes, conjugated dienes containing heteroatom, conjugated enyne containing heteroatom etc., enriching methodologies for organic synthesis.

继而研究了这些新型双官能试剂在过渡金属配合物催化下分别与亲电试剂、亲核试剂的顺序交叉偶联反应，为双取代烯烃、三取代烯烃、杂原子取代的共轭二烯烃、杂原子取代的共轭烯炔烃等的立体选择合成提供了方便实用的新方法，丰富了烯烃立体选择合成的方法学。

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。

The reactions of several phenols and 2, 2, 6, 6-tetramethyl-4-substituted piperidine oxoammonium salt have been studied. It was found that these oxoammonium salts are new facile reagents for phenolic coupling.

应用2，2，6，6-四甲基哌啶氧铵盐实现了酚类的氧化偶联反应：对位取代的酚类底物得到邻位-邻位偶联产物；2，6-二取代的酚类底物得到对位-对位偶联产物；2，4，6-三取代的阻碍酚类底物得到苄位氧化偶联产物。

The invention concerns a process for preparing heterocyclic carbenes of general formula in which R1, R2, R3 and R4 are identical or different and mean saturated or unsaturated, straight-chain, branched or cyclic, unsubstituted or substituted C1-C10 alkyl, C2-C5 alkylidene, C2-C5 alkylidine, C7-C19 aralkyl or C6-C14 alkyl groups, R3 and R4 can also stand for hydrogen or form jointly anellated, substituted or unsubstituted groups with between 3 and 7 carbon atoms and X stands for carbon or nitrogen, R3 being dropped if X is nitrogen.

本发明涉及一种制备通式Ⅰ的杂环碳烯的方法，其中在通式Ⅰ中，R1、R2、R3和R4是相同的或不同的，并且是饱和的或不饱和的，直链、支链或环状的，未取代或取代的C1－C10－烷基、C2－C5－亚烷基、C2－C5－次烷基、C7－C19－芳烷基或C6－C14－芳基基团，R3和R4可以是氢或它们一起形成具有3－7个碳原子的稠合的、取代或未取代的基团，X是碳或氮，并且当X是氮时，不存在R3。

To our surprise we achieved the ligand 9, 11 and 29 with coordinating atoms fixing at benzylic and benzene ring positions, whose structure is unique in the planar chiral cyclophane chemistry.

以钯催化的烯丙基取代反应对配体进行了考察，硫醚或硒醚取代基在苄位取代的配体表现出更高的反应活性和更高的对映选择性，配体9和11均给出最高为94％的ee值。

Direct competitions of intramolecular C - H insertions into benzylic C - H and 4-nitroor 4-methoxy substituted benzylic C - H of methyl 2-diazo-3-oxo-6-(4-substituted phenyl)-4-(2-phenylethyl)hexanoate 44a and 44b catalyzed by Rh-mediated carbenoid were alsoinvestigated, and the relative reactivities obtained by compound 44a or 44b were comparableto those obtained by indirect method.

此外，还研究了Rh催化分解下，对位硝基取代或甲氧基取代的4-(2-苯基乙基)-6-(4-取代苯基)-2-重氮基-3-氧代己酸甲酯44a、44b苯甲位C-H插入反应的相对速率，与化合物47a和47f得到的结果比较，数据平行。

The positive charge transport properties of monosubstituted triphenylene are better than those of disubstituted and trisubstituted triphenylenes obviously.

在苯并菲上单取代的分子明显比其双取代、三取代的分子正电荷传输性质好。

An optically clear thermoplastic resin composition consisting essentially of: structural units derived at least one substituted or unsubstituted polycarbonate, at least greater than 30 weight percent of a substituted or unsubstituted polyester, a modified polycarbonate, an impact modifier having a refractive index in the range between about 1.51 and about 1.56 and an additive is disclosed.

公开了一种光学透明热塑性树脂组合物，该组合物基本上由以下组成：结构单元衍生的至少一种取代的或未取代的聚碳酸酯，至少大于30wt％的取代的或未取代的聚酯，改性的聚碳酸酯，折射率范围为约1.51～约1.56的抗冲改性剂和添加剂。

Well-resolved absorption spectra of benzoic acid and its derivatives with one hydrogen atom replaced by a substituent group CH3, OH, NH2 or NO2 were reported in the frequency region between 6 and 67 cm－1 at room temperature with terahertz time-domain spectroscopy.

本文利用太赫兹时域光谱技术获得了295K时苯甲酸，不同位置取代的甲基苯甲酸以及不同取代基对位取代苯甲酸在6至67 cm-1波段的时域光谱。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。