映

PK values of 3-ethoxy-N-desmethyldiazepam (3-EtO-NDZ) in ethanol and acetonitrile containing various concentrations of sulfuric acid, determined by spectrophotometry and spectropolarimetry, were found to be 3.4 and 0.63 respectively. Temperature dependent racemization of enantiomeric 3-EtO-NDZ in ethanol containing various acid concentrations was studied by monitoring changes of ellipticity at 365 nm as a function of time on a spectropolarimeter.

3-乙氧基－N去甲基安定（3-EtO-NDZ；diazepam=安定）在含不同硫酸浓度的乙醇和乙腈中的pK值用光谱法和旋光光谱法作了测定，其结果分别为3.4和0.63.3-EtO-NDZ之对映异构体在含各种不同酸浓度的乙醇中与温度相关的消旋过程，用旋光光谱仪选择其圆二色谱在365nm波长处强度的改变为时间函数的方法作了测定。

There are some spotlessly white truths and dark shadows emerge together and reflect each other.

有一些洁白的真相和黑暗的阴影，一起出现，互相衬映。

The stereochemical studies of PPCs derived from the copolymerization of CO_2 with chiral PO at various conditions reveal that the polymer enantioselectivity is proportional to its head-to-tail linkages with regard to regioselective ring-opening of the epoxide.

通过研究聚碳酸酯的立体化学发现聚合物的对映体选择性与环氧丙烷区域选择性开环存在一定的影响作用。

Some studies showed that SPs display toxicity to wildlife and human nervous systems. It may cause acute and chronic neurotoxicity to mammal, and the stereoisomeric structure of SPs affects mammals neurotixicity. There was some enantioselectivity of SPs in acute and chronic neurotoxicity to mammal.

已有研究结果显示拟除虫菊酯类农药对非靶标野生动物和人类的神经系统有一定的毒性作用，其对哺乳动物的神经毒性主要表现为急性和慢性神经毒性，而且其毒性作用与拟除虫菊酯类农药的立体结构相关，有一定的对映体选择性差异。

In addition, higher enantioselectively was obtained when the groups on the oxazoline ring were less sterically demanding. That is, substrate will be closer to the backbone of ferrocene.

我们发现当恶唑啉上取代基立体位阻减小时我们发现当恶唑啉上取代基立体位阻减小时，产物的对映选择性就会相对较高，因而平面手性的影响很可能就是通过二茂铁非取代茂环和底物及亲核试剂之间的相互作用而产生的。

The facts indicate that apart from the asymmetric induction of chiral diamine backbone,sterically hindered substitute groups on the aromatic rings,and the presence of sp~3-hydridized amino donors and its N,N\'-disubstituted groups in chiral SalanCrX complexes all play important roles in controlling polymer stereochemistry and enantioselectivity.

研究发现除了手性二胺骨架的不对称诱导作用，苯环上的大位阻取代基、N，N\'-二取代基的位阻作用以及N原子上sp~3杂化的供电子效应都对调控聚合物的区域和对映体选择性有很大作用。

At twilight,the sky is suffused with color.

黄昏时天空映满色彩。不适合

The ligand of the chiral Schiff base and acetylacetone vanadium are subjected to complexation in situ, hydrogen peroxide is taken as an oxidant, aryl alkyl thioether asymmetric oxidation reaction is catalyzed in a toluene or dichloromethane solution under low temperature or room temperature, enantioselectivity of chiral sulphoxide is 72 percent to 95 percent ee, and yield is 42 percent to 83 percent.

将上述手性西佛碱配体与乙酰丙酮氧钒原位络合，采用双氧水为氧化剂，在甲苯或二氯甲烷溶液中低温至室温下催化芳基烷基硫醚不对称氧化反应，手性亚砜的对映选择性为72％-95％ee，产率为42％-83％。

Whereafter,we achieved a highly enantioselective approach towards the synthesis ofβ-substituted chiral ketones utilizing Oppolzer\'s sultam as chiral auxiliary.The-and-enantiomer of target chiral ketones were obtained with up to 99%ee.

应用手性辅剂樟脑磺内酰胺的手性诱导作用，高对映选择性地合成了一系列β-芳基取代手性酮，其ee值高达99%，可用于药物及其它精细化工中间体的不对称合成。3。

As one of famous work that often abandon a gentleman, huang Lei, Jiang Qin diligent, Zhao Baogang, yuan autumn wait for actual strength to go out act " 4 worlds are the same as hall " when actor is mirrorred sultrily, also caused a netizen to be opposite old 1985 edition " 4 worlds are the same as hall " nostalgic heat, daily number netizen is chased after read old old edition anthology of classic theatrical work, savor authentic Beijing taste.

作为老舍先生的著名作品之一，黄磊、蒋勤勤、赵宝刚、元秋等实力出演的《四世同堂》在优酷热映之际，也引发了网友对1985年旧版《四世同堂》的怀旧热，每日数万网友追看老旧版经典剧集，品正宗京味。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。