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In the reduction of 1, 6-diphenyl-1, 6-hexanedione catalyzed by the bis-squaryl proline, good enantioselectivities were obtained, the ee values were up to 90%.We also studied the asymmetric borane reduction of prochiral ketone catalyzed by a series of thiazolidine ligands.

本文考察了由L-半胱氨酸衍生的2-位无取代基的以及2-位芳基取代的噻唑烷酸及醇配体在前手性酮的不对称还原反应中的催化性能。

3A series of C_2-symmetric chiralβ-amino alcoholsⅢ-6 andⅢ-10were synthesized in several steps from natural amino acids,and applied in the asymmetric borane reduction of prochiral ketones.The catalytic activity ofⅢ-6 was better thanⅢ-10.

3以天然氨基酸为起始原料，经过简单的几步反应合成了开链冠醚类C_2-对称的手性β-氨基醇Ⅲ-6以及Ⅲ-10，将其应用于硼烷对前手性酮的不对称还原反应中，含有脯氨醇结构单元Ⅲ-6的催化效果要好于由其他氨基酸衍生的Ⅲ-10，THF为溶剂，回流，催化量为10 mol%时，最高得到85%的ee值。

S-1-phenylethanol was obtained in up to 19%ee in toluene at 0℃.(4)A series of C_2-symmetric chiralβ-amino alcoholsⅣ-5were synthesized in several steps from natural amino acid L-proline,and applied in the asymmetric borane reduction of prochiral ketones.

4以天然L-脯氨酸为起始原料，经过几步转化合成了以萘环为母体的C_2-对称的手性β-氨基醇Ⅳ-5，将其应用于硼烷对前手性酮的不对称还原反应中，同样，我们也观测到温度影(来源：Ac1BC论文网www.abclunwen.com)响产物构型的现象。

Asymmetric catalytic activity of chiral spiroborate esters,- or-1,1′-bi-2-naphthoxyboric acid-proline anhydride [-1 or-1], toward borane reduction of prochiral imine s has been ob- served.

手性螺硼酸酯-或-1，1'-联-2-萘酚硼酸--脯氨酸酐[-1或-1]对前手性亚胺硼烷还原的不对称催化活性被观察到。

The results revealed an asymmetric perceptual span that extended 1 or 2 characters to the left of the fixated character and 3 or 4 characters to its right. The size of right-directed sac?鄄cades extended about 3 characters in normal reading, suggesting that the perceptual spans of successive fixations overlapped slightly and some linguistic information was integrated across fixations.

结果发现，高中二年级学生的阅读知觉广度具有不对称性，大约为注视点左侧一个或两个汉字到注视点右侧三个或四个汉字的空间；高中二年级学生在正常阅读中的眼跳距离约为三个汉字的空间，在连续注视的过程中知觉广度有较小范围的重叠。

Finally, analyse the calculated results of this ship with another catamarans. From this result obtained unsymmetrical catamaran hull of this particular special vibration mode and analyse the vibration mode in order. The calculation is fairly reasonable, for the future of the asymmetric catamarans to calculate the vibration analysis of a number of reference.

最后将本船计算结果与另一艘双体船计算结果进行了比较分析，得到不对称双体船这种特殊船型的特殊振动模态，并就其振动模态出现次序进行了比较分析，说明本次计算是比较合理的，为今后不对称双体船的振动特性分析计算提供了一些的参考。

The organic molecules with it-conjugated structure are ideal structural units for molecular wires. The asymmetric electronic structure of the molecular junctions is the basic reason for molecular rectification. Rotaxanes and catenanes are ideal structural units for molecular switches. The operation principle of molecular field effect transistors is quantum tunneling, the metal/insulator/mental tunneling is mainly.

具有π-共轭结构的有机分子体系是构造分子导线的理想单元；分子结的电子结构不对称性是分子具有整流特性的根本原因；轮烷和索烃是构造分子开关的理想单元之一；分子场效应晶体管的工作原理是量子隧穿，主要是金属－绝缘体－金属间的隧穿效应。

Its coats came overlaid with quilted, shaggy string, dresses bore asymmetric pleated chiffons, and evening coats came densely embroidered.

Rodarte的外套上饰有蓬松柔软的棉线，长裙上镶嵌着不对称的雪纺褶皱，并且晚礼服上会有密密的镶边。

Along with the rapid development of our country's Industy, the factors induce that the power plant combusts the single coal impossibly for a long time, which are the increase wastage of coal, the difficulty transportation, the asymmetric distributing of coal mine and the policy of nation about that power boiler combusts inferior coal, therefore, the power plant must combusts blended coals.

随着我国工业的快速增长，煤的消耗量增加，加上运输困难、煤矿分布不均匀以及国家有关对燃煤锅炉尽量燃用劣质煤的政策等因素，造成电厂不可能长期燃用单一煤种，而不得不燃用配煤。

Total knee arthroplasties with an asymmetric tibial tray and posterior femoral condyles were implanted in 224 knees.

共224个膝关节应用非对称性的胫骨支架和股骨后髁行全膝关节置换手术。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失