对称

By changing alkali metal ions, we can adjust and mix different intensity of blue light according to the demand.

根据J-O理论，计算其光学跃迁的强度参数Ω2和Ω4，可以获得材料结构的有序和对称情况。

Interlayer spacings of all the alkylamine intercalates are linearly proportional to their alkyl chain lengths.

十二胺和十六胺嵌入较难，得到的嵌入物结构不规整，代表层状结构的(001)峰不对称。

We transformed RMgBr into R-Ti derivatives with the production of byproduct MgBrO~(i-Pr at the same time, but we didn\'t need romove the Mg salt by centrifugation or chelating reagents, for bis[2-(N,N-dimethylamino)ethyl] ether could chelate with Mg atom and thereby reduced the Louis acidity of Mg salt, so we used R-Ti derivatives produced in situ to alkylate the aldehydes induced by BINOL-Ti complexes..

我们通过利用TiO~(i-Pr_4使格氏试剂转化成烷基钛，同时产生具有亲核加成促进作用的副产物MgBrO~(i-Pr，由于BDMAEE能与MgBrO~(i--Pr络合降低其路易酸活性，所以不需要离心或者借助络合试剂完全除去镁盐，而使用原位生成的烷基钛在BINOL-Ti诱导下对醛进行不对称加成。

These ligands were found to be very effective in construction of quaternary carbon centers by using asymmetric allylic alkylation.

这类配体在前手性亲核试剂的不对称烯丙基化构筑手性季碳中心的反应中，显示了较好的反应活性及对映选择性。

The ligands were found to be effective in palladium-catalyzed asymmetric allylic alkylation to construct chiral quaternary carbon center.

这类配体在前手性亲核试剂的不对称烯丙基化构筑手性季碳中心的反应中，显示了较好的反应活性及对映选择性。

After hydrogenation of the double bond and the addition of alkyne to a carbonyl we introduced the N-hydroxy group by SN2 reaction.

不对称氢化和炔负离子对羰基的立体选择性加成构建了两个新的手性中心，之后用羟胺衍生物对羟基的SN2取代反应引入了羟胺片断。

SAA ligand Lh could induce asymmetric addition of terminal alkyne to aldehydes without using air-sensitive Ti4and expensive Zn2.with good result of high yield (up to 99%) and good enantioselectivities (up to 84%ee).

将SAA配体Lh应用于在无Ti_4和Zn_2的条件下促进端基炔对醛的不对称加成反应中，反应的收率普遍较高，最高达99%，对映体选择性高达84%ee。

The headquarters of conglomerates using of tunneling of internal capital market seize and plunder resources of listed companies because of the Government's restrictions on market allocation, low liquidity of capital markets, and the problem of "adverse selection" causing by serious information asymmetry and so on.

因为政府对市场配置限制，资本市场低流动性以及严重的信息不对称导致的"逆向选择"等问题使得许多的集团公司总部利用内部资本市场利益输出行为侵占、掠夺上市公司资源。

Lightfoot et al have developed one of these iridium-based systems for the stereocontrolled synthesis of lilial by asymmetric reduction of an allyl alcohol and subsequent oxidation of the alcohol.

Lightfoot等发展了一种基于铱的系统，通过烯丙醇和第二阶段酒精氧化的不对称还原，用来进行铃兰醛的立体控制合成。

Synthesis and application of 1, 1'-ferrocene P, N -ligands in enatio- and regio-selective palladium-catalyzed allylic substitution reactions

1， 1'-二茂铁膦氮配体的合成及其在不对称区域选择性钯催化烯丙基取代反应中的应用

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。