不对称

Leaves alternate, often opposite or whorled in Peperomia , simple, base often asymmetric, palmately or pinnately veined.

叶互生，通常对生或轮生在Peperomia内，单，不对称的基部通常，掌状或成羽状脉。

This article analyzes the legal regulation model of environment protection from the perspection of exteriority,public goods,and information asymmetry.

本文从外部性、公共产品、信息不对称三个使&市场失灵&的角度分析了环境保护问题的法律调整模式，认为解决环境问题需要&看得见的手&和&看不见的手&兼而用之。

This review covers the application of bioreduction to the saymmetric synthesis of pharmacologically active compounds on a alboratory and a commercial scale.

综述了近年来利用生物还原方法进行制备量和商业规模的不对称合成手性药物的进展。

New chiral phosphonic acids and zirconium phosphonates might have potential applications in asymmetric synthesis, enantioseparation and biochemistry.

手性有机膦酸及新手性层状膦酸-磷酸锆在不对称合成、对映体拆分和生物化学都可能有潜在的应用。

New methods for asymmetric synthesis of pinacol are reviewed, the catalytic effects and stereo- selectivity with various catalytic systems are discussed in this paper.

综述了近年来不同催化体系的不对称合成呐醇的方法，并总结了不同的催化效率和对映选择性的差异

The 91% ee value was obtained by the pinacol coupling reaction catalyzed by 15mol% Schiff-base prepared by the chiral 1, 2-Diphenyethylenediamine and 2-pyridinecarboxaldehyde.

2由手性1，2-二苯基二胺与两分子2-吡啶醛缩合的Schiff-Base催化的Pinacol偶联反应，仅用15mmol％的量，可取得91％的ee值，这是不对称Pinacol偶联反应最好的结果之一。

Results show that for KEMAR mannequin,pinnae destroy the front-back symmetry of HRTF above 5～6 kHz,while for human subjects it reduces to 2.5 kHz because of the locations of ears.

结果表明，在5 kHz至6 kHz以上的频率，耳廓破坏了头相关传输函数的前后对称性；而受耳道入口位置的影响，真人受试者的头相关传输函数在2.5 kHz以上的频率就开始出现前后不对称。

Leaves alternate, pinnately veined, with strongly parallel secondary veins, base often asymmetrical, margin entire.

叶互生，成羽状脉，具强烈平行次脉，不对称的基部通常，边缘全缘。

We screened a set of Lewis base organocatalysts derived from chiral pipecolinic acid and tert-butanesulfinamide for the reduction of-N-Cbz-1- phenylpropenamine, including newly designed ones and some of those previously developed in our lab. However, only moderate stereoselectivities, albeit high yields were obtained.

在本课题组前期研究的基础上，我们筛选并设计了一系列以手性哌啶酸和叔丁基亚磺酰胺为母体的有机小分子路易斯碱催化剂，它们能催化三氯氢硅对-N-苄氧羰基-1-苯基丙烯胺的不对称还原，获得很高的收率和中等的对映选择性，并且具有很好的底物普适性。

Starting from chiral proline, pipecolinic acid, piperazine-2-carboxylic acid and 1,2-diphenyl amino alcohol, a series of structurally simple and easily prepared amides were developed as highly effective Lewis basic organocatalysts for the asymmetric reduction of imines with trichlorosilane as the reducing agent, which promoted the reduction of N-aryl imines with high yields and excellent enantioselectivities with an unprecedented substrate spectrum.

本文分别由手性脯氨酸、哌啶酸、哌嗪酸以及氨基醇出发，设计和合成了一系列结构新颖、合成简便、性能优良的酰胺类有机小分子路易斯碱催化剂，以廉价的三氯氢硅为氢源，用这些催化剂催化亚胺不对称还原，得到了非常优良的收率、对映选择性和前所未有的底物普适性。

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％。