时基

The invention concerns a process for preparing heterocyclic carbenes of general formula in which R1, R2, R3 and R4 are identical or different and mean saturated or unsaturated, straight-chain, branched or cyclic, unsubstituted or substituted C1-C10 alkyl, C2-C5 alkylidene, C2-C5 alkylidine, C7-C19 aralkyl or C6-C14 alkyl groups, R3 and R4 can also stand for hydrogen or form jointly anellated, substituted or unsubstituted groups with between 3 and 7 carbon atoms and X stands for carbon or nitrogen, R3 being dropped if X is nitrogen.

本发明涉及一种制备通式Ⅰ的杂环碳烯的方法，其中在通式Ⅰ中，R1、R2、R3和R4是相同的或不同的，并且是饱和的或不饱和的，直链、支链或环状的，未取代或取代的C1－C10－烷基、C2－C5－亚烷基、C2－C5－次烷基、C7－C19－芳烷基或C6－C14－芳基基团，R3和R4可以是氢或它们一起形成具有3－7个碳原子的稠合的、取代或未取代的基团，X是碳或氮，并且当X是氮时，不存在R3。

It was found that the binaphthyl backbone of S configuration was matched to the S, S pyrrolidino group. In this case, the asymmetric allylation product could be obtained in 85. 6% ee.

轴手性是S构型时，和中心手性S，S构型相匹配，它和钯形成的络合物在催化烯丙基取代反应时，取得了比不含中心手性因素的吡咯烷基氮膦配体高得多的对映选择性，可以得到85.6％ee值的产物。

In this system, the allylation was selectively toward aldehyde in the presence of ketone; the allylation squinted toward aliphatic aldehyde in the presence of aromatic aldehyde.

该方法不仅对于醛和酮具有很高的化学选择性，而且对于芳香醛和脂肪醛也有很好的选择性，当存在芳香醛时，脂肪醛优先发生烯丙基化反应。

When a strong and slowly degrading scaffold is used, the starting position of alular tissue engineering is a stronger ale and seeded cells are allowed more time to create a strong extracellular matrix.

当使用一个强壮的降解缓慢的支架时，瓣膜组织工程的起始点是一个更加强壮的瓣膜，种植的细胞有更多的时间创造强壮的细胞外基质。

The amidation and esterification of different cyclic anhydride s with aniline and phenol gave different major products,and the routes were optimized.

结果表明，环酐的分子结构直接影响反应结果，当酸酐分子存在共轭结构时以N-芳基内酰胺为主要产物。

As to the curing reaction of the modified phenolic epoxy resins, there is the etherification reaction between phenolic hydroxyl groups and epoxy groups. When the secondly modified epoxy resins are cured at higher temperatures respectively, the absorbance increasing at 1670Cm〓 and 1640Cm〓 are indicative of aminolysis reaction.

对于改性酚醛环氧树脂的固化反应，有酚羟基和环氧基间的醚化反应，二次改性环氧树脂在较高的温度固化时，1670Cm〓和1640Cm〓吸收峰的增加说明有氨解反应。

At first,only young women worked at the Amoskeag mills.

刚开始时，只有年轻妇女在埃默斯基格的工厂里工作。

In the days of Phacee king of Israel came Theglathphalasar king of Assyria, and took Aion, and Abel Domum Maacha and Janoe, and Cedes, and Asor, and Galaad, and Galilee, and all the land of Nephtali: and carried them captives into Assyria.

以色列王培卡黑在位时，亚述王提革拉特丕肋色尔前来，侵占了依雍、阿贝耳贝特玛阿加、雅诺亚、刻德士、哈祚尔、基肋阿得、加里肋亚和纳斐塔里全地；并将这些地方的居民都掳往亚述。

In the days of Phacee king of Israel came Theglathphalasar king of Assyria, and took Aion, and Abel Domum Maacha and Janoe, and Cedes, and Asor, and Galaad, and Galilee, and all the land of Nephtali: and carried them captives into Assyria.

以色列王培卡黑在位时，亚述王提革拉特丕肋色尔前来，侵佔了依雍、阿贝耳贝特玛阿加、雅诺亚、刻德士、哈祚尔、基肋阿得、加里肋亚和纳斐塔里全地；并将这些地方的居民都掳往亚述。

This is K.c. the publisher of Automotor News.

汽车时讯的出版人，基斯。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。