硼

When used in superabrasive grits synthesizing, especially in the case of cubic boron nitride, the consumption of anvils can be decreased effectively; and the quality and yield of CBN can he improved.

在超硬材料合成中，尤其是立方氮化硼合成中，能有效降低锤耗，同时可提高立方氮化硼的合成品质及产量；超硬材料表面镀钛及钛合金后，能实现镀层和结合剂的冶金结合，工具寿命提高30%以上；钛对许多氧化物质和还原物质具有极好的耐腐蚀性，适用于人造金刚石的批量电解提纯工序。

Asymmetric hydroboration is a kind of widely applied and valuable reaction, in which borane reduction of prochiral ketones reaction is an important method.

不对称催化硼氢化反应是应用广泛且具有工业价值的反应，其中的硼烷还原前手性酮反应有着举足轻重的作用。

Part Ⅰ The Research of Chiral Phosphorus Catalysts in the Enantioselective Borane Reduction of Prochiral Ketones ABSTRACT In this paper, the preparation of varied types of chiral phosphorus ligands and their applications as catalysts in the asymmetric borane reduction of prochiral ketones were investigated.

第一部分对映选择的潜手性酮的硼烷还原反应中手性磷催化剂的研究本文研究了多种不同类型的手性磷配体催化剂的合成及其在酮的不对称硼烷还原反应中的应用。

The best results 98% ee, 94% ee and 59% ee were obtained in silylcyanation of aldehydes, borane reduction of prochiral ketones and ketimines, respectively.

醛的硅氰化反应ee值最高达到98%，酮的硼烷还原反应ee值达94%，而亚胺的硼烷还原反应ee值只有59%。

Carborane, an important specie of borane derivatives, obtained by replacing BH or BH- group with C or CH, have applied in many fields due to its representative structure and special bond.

碳硼烷是用C原子替代BH单元或用CH单元替代BH-单元形成的一类重要的硼烷衍生物，其构型的典型性以及化学键的特殊性，在很多方面都有所应用。

Oxazaborolidine, which derive from the coordination of amino alcohol and borane, are good catalysts for the borane reduction reaction. A kind of fused cyclic oxazaborolidine invented by Corey and derived from proline has been successfully used in the production of MK-0417 as excellent chiral catalyst by Merck company.

在该反应中氨基醇类配体原位与硼烷配位形成的手性恶唑硼烷是该反应的良好催化剂，其中Corey等发明的由脯氨酸出发制备的稠环手性催化剂性能优异，已经在Merck公司生产碳酸酐酶抑制剂MK-0417中得到成功应用。

Thirty-one new chiral phosphorus compounds have been synthesized starting from D-camphor,-alpha-phenylethylamine,-Betti base,-1-(4-nitrophenyl)-2-amino- propane-1,3-diol, L-amino acids (such as serine, phenylalanine, proline etc.) and their application as organocatalysts in asymmetric trimethylsilylcyanation of aldehydes and asymmetric borane reduction of prochiral ketones and ketimines were investigated.

该项目从D-樟脑、-alpha-苯乙胺、-Betti碱、-氯酶胺、L-氨基酸（如丝氨酸、苯丙氨酸、脯氨酸等）出发合成了31个新的手性磷化合物，研究了它们作为有机催化剂在醛的不对称硅氰化反应、潜手性酮的不对称硼烷还原反应以及亚胺的不对称硼烷还原反应中的催化效果。

Borides were distributed in the shape of continuous net in the structure of high boron iron-base alloy.

高硼铁基合金是一种以硼化物为耐磨相的新型耐磨材料。

By studying the actuality of experimental and research, the advantages of preparating boron and metal borides powder with molten salt electrolysis are much easier, less expensive and environmentally friendly and high purity of products.

结合国内外实验与研究的现状，分析认为，熔盐电解法制备与生产单质硼粉及金属硼化物的优点是环境友好、反应条件容易控制、产品纯度高，是很有前途的方法。

Borides are promising candidates for wear resistant materials. But poor sinterability and extreme brittleness of borides retarded their application. Reaction boronizing sintering method has solved this problem.

硼化物是一种优良的耐磨材料，但由于其较差的烧结性能和极大的脆性限制了这种材料的应用，反应硼化烧结法很好地解决了这一问题。

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％。