廉价

The target compound 1 was successfully prepared via esterification, reduction, bromization and cyanation processes by using L--malic acid (2), which is an inexpensive and easily available starting material. The overall yield was 56.7%.

以廉价、易得的L--苹果酸为起始原料，经酯化、还原、溴代和氰化四步反应得到目标化合物-4-氰基-3-羟基丁酸乙酯，合成总收率为56.7%。

The overall yield was 43.6%.The yield of reduce of ester was increased nearly one times than the past method because of KBH4-LiCl as the reducing agent instead of NaBH4. Changing the reaction conditions of bromization, the one-way yield enhanced 30%. The yield of reduce of the bromide was added by one times by improving the process. Tefluthrin was achieved by the catalytic esterification of DCC and DMAP.

优化后工艺对四氟对苯二甲酯的还原采用了廉价高效的还原试剂KBH4-LiCl，使收率比NaBH4法提高了近一倍；对溴化反应条件进行了优化，单程收率提高了30%；对溴化物还原条件的优化，使其收率提高了近一倍；采用了催化剂DCC和DMAP合成了最终产品七氟菊酯。

In recent years, as the Maleic anhydride is being produced in larger scale a number the investigation have been reported on the hydrogenation of the MA to SA,γ-butyrolactone , succinic anhydride , tetrahydrofuran and 1, 4-butanediol which are important chemicals in medicine, pesticide and petrochemistry.

近些年来，由于顺丁烯二酸酐生产规模的大型化，以廉价的顺丁烯二酸酐为原料合成高附加值化学品的研究倍受青睐。

Agricultural lime, either finely ground dolomitic or calcitic limestone, applied directly to acid soils is an inexpensive way to increase crop yields and reduce fertilizer input costs.

农用石灰，不管是粉细的白云石质石灰岩，还是方解石质石灰岩，直接施到酸性土壤是提高作物产量和降低肥料成本的一条廉价途径。

In this thesis, several novel reaction-controlled chiral phase-transfer catalysts were designed and synthesized from readily available materials, and were used in the asymmetric epoxidation of unfunctionalized olefins and chalcone.

本文以有机合成方法学为目标，从廉价的原料出发，合成出几个新的反应控制的手性相转移催化剂，并且检验了他们在催化烯烃的不对称环氧化中的催化效果。

It's, you know, like rags to riches. I was one of those kids living in the small suburb kind of a slum, kind of a chawl, which we call a chawl.

我就是从小住在郊区小贫民窟的小孩之一，住在那种廉价的破烂出租公寓，我们称之为 chawl。

His parents moved to a suburb, but their house is just a cheesebox.

他的父母搬到郊区，但住的仅是间廉价小屋。

Instead cheap wedding dresses, take some time Wedding Gowns, and plan the jewelry Wedding Gowns, style you are looking wedding dresses, for based on your wedding.wedding dresses, IF you have some wedding dresses, ideas of what you Prom Dresses, want like a 2009 Wedding Gowns, chocker or pearls then you can use this when you wedding dress, go shopping.

而不是廉价的结婚礼服，花一些时间结婚礼服，并规划珠宝婚纱礼服，样式正在寻找婚纱，为基于您wedding.wedding服装，如果你有一些婚纱，你的舞会礼服，希望类似建议2009年的婚纱礼服，chocker，珍珠，那么你可以使用这个当你结婚礼服，去购物。

Calf rennet, consisting of mainly chymosin with a small but variable proportion of pepsin, is a relatively expensive enzyme and various attempts have been made to find cheaper alternatives from microbial sources These have ultimately proved to be successful and microbial rennets are used for about 70% of US cheese and 33% of cheese production world-wide.

与其他凝乳酶一起组成了一个虽小然而却有很大比率的胃蛋白酶的幼牛凝乳酶相对来说比较昂贵，因此目前关于能否在微生物资源中寻找廉价的凝乳酶正在试验中。这一设想最终一定会成功并且从微生物中得到的凝乳酶将会用于生产美国市场中77%，全球市场33%的乳酪制品。

Then,some contrastive experiments on producing cyanuric acid by heating up different kinds of solvent to eliminate hydrogen were done.

以不同溶剂加热脱氢生产氰尿酸的收率和纯度做了对比实验，并通过选择确定硅油210 50是一种新型的理想的和廉价的溶剂。

The basic concept of FOP can be summarized as to further optimize effective prescription according to the standard of curative effects and with the aid of modern science and technology and theories of traditional Chinese medicine.

其基本内涵可概括为：以确有疗效的中药复方为研究对象，以现代科学技术和传统中医药理论为技术支持，以该复方所治病证的药效响应为评价标准，以优化重组疗效更优的新复方为研究目的。

Ever since our world has been a world, native forests have been indiscriminately exploited by man.

自从我们的世界一直是世界原生森林被任意剥削人。