查询词典 afford

Contrastingly, those who are in an urgent need for houses can not afford them.

懂经济的同学可以在这基础上做些修改，说得更深入一些。

In the second approach, terephthalaldehyde was also used as starting material, which reacted with cyanoacetic acid in pyridine to afford tetra-nitrile compound.

在第二种合成路线中，我们仍然以对苯二甲醛为起始原料，对苯二甲醛与氰基乙酸反应得到四氰基化合物8，再经过官能团转换、还原、亲核取代、分子内Friedel-Crafts反应得到中间体H〓TTPR。

How did the centripetal remainer afford egress to the centrifugal departer?

381向心的滞留者是怎样为离心的出发者提供出口的？

Nitroarenes can be reduced by samarium diiodide to afford a nitrogen anion,which is a living species and can be acylated by relatively weaker acylating ester agents.

二碘化钐(SmI2)在四氢呋喃溶剂中还原硝基化合物，可以生成氮负离子中间体，该中间体具有较高的反应活性。

Treatment of dials with N-tert-butanesulfinamide, all biaryl dials were successfully converted into the corresponding bis-imines which were then treated with samarium diiodide to afford diamine products. The absolute configurations of all the intramolecular coupling products were determined by X-ray crystallography.

轴手性二醛与N-叔丁基亚磺酰胺缩合得到相应的亚胺，其为一对非对映异构体。N-叔丁基亚磺酰亚胺在二碘化钐条件下得到的偶联产物，经X-衍射也确定了其立体构型。

The chapter two was focused on the samarium diiodide promoted organic reactions and their applications in organic synthesis, firstly, a new synthesis of highly substituted cyclopentadienes from a,β-alkynone promoted by samarium diiodide was investigated and the highly substituted cyclopentadienes were prepared in moderate to good yields under mild conditions. Secondly, the Michael addition and Michael-aldol tandem reaction of diorganyl diselenides or diorganyl disulfides with α,β-alkynones mediated by samarium diiodide were studied and a series of alkenylsulfides and alkenylselenides were prepared in good yields. Then the highly regioselecfive nucleophilic addition of the allylsamarium bromide to α,β-alkynones were explored. We found that the allylsamarium bromide reacts with α,β-alkynones to afford regiospecificly 1. 2-nucleophilic addition products in good yields under mild condition. At last we studied the coupling reaction of aryl halides promoted by NiCl〓/PPh〓/Sm〓.

第二章 研究了二碘化钐、金属钐促进的有机反应：1、二碘化钐促进下α，β-炔基酮的偶联环化反应，提供了一种制备多取代环戊二烯的新方法；2、二碘化钐促进下的二硫醚、二硒醚与α，β-炔基酮的Michael加成反应，为高产率地制备多取代的烯基硫或烯基硒化合物提供了方便可靠的新方法；3、二碘化钐促进下的二硫醚、二硒醚与α，β-炔基酮和醛、酮的Michael—aldol串联反应，提供了一种一锅法高产率地制备多取代的含硫的烯丙基醇或含硒的烯丙基醇类化合物的方便可靠的原子经济性的新方法；4、烯丙基溴化钐与α，β-炔基酮的高度区域选择性的1，2-亲核加成反应；5、NiCl〓/PPh〓/Sm〓促进的卤代芳烃的偶联反应-一种从各种卤代芳烃制备联苯类化合物的有效方法。

After studying the disseminative process of liberalism, this article conveys that because liberalism could not afford systematic and effective schemes on the level of social transformation on one hand, and on the other hand, it could not provide resource of valuable rectification and integration on level of culture spirits. Therefore, liberalism's failure was an inevitable choice in modern times in China.

本文通过对自由主义在中国近代传播的历史进程考察后分析认为，由于自由主义一方面既不能从社会改造的层面提供系统有效的方案，另一方面也不能从文化精神层面为社会提供价值整合资源，因而，自由主义在近代中国的失败是历史必然的选择。

The synthesis rst involves the nucleophilic substitution reaction of tosylates 1a– 1c with 2,3-dicyanohydroquinone (2) to afford the disubstituted phthalonitriles 3a–3c.

综合第一涉及的亲核取代反应tosylates 1A至 1C号与2，3 - dicyanohydroquinone （ 2 ）负担取代 phthalonitriles 3A条- 3C飞机。

Now that he published a earthliness novel ,he can afford a new house and a car.

他出版了一本通俗小说，赚了很多钱，所以他有能力买心房和轿车。

I don\'t think we can afford the e XP ense.

我认为我们负担不了这个费用。

Means the parent directory, so this command means to execute "toolchain.sh," which is in the current directory.

代表父目录，所以这个命令就是执行当前目录下的"toolchain.sh"。

Yes,In fact,I'm on our city ream.

是的。事实上我是我们市队的。