四代的

This new methods can shun corrosiveness of liquid bromine or gas hydrogen bromide released during bromating reaction to the equipments and eliminate harmfulness to the operating worker and environment.

研究以溴化钠/溴酸钠完全代替传统的溴素作为溴代试剂合成了四溴双酚A，避免了使用溴素和因溴素作为溴代试剂时产生的溴化氢对设备、操作人员以及环境的危害。

Enaminones are also valuable precursors for α-iodol enaminones, 3-amino sugar derivatives, azo-compounds,β-aminoketone, as well as tetrahydropentalenes, tetrahydroindenes, and hexahydroazulenes.

烯胺酮类化合物同时也是α-碘代烯胺酮类化合物、3-氨基糖衍生物类化合物、氮杂化合物、β-氨基衍生物类化合物和四氢并环戊二烯类化合物和四氢茚类化合物的重要前体。

Rotation matrix s representation with the unit quaternion has no singular points, so the unit quaternion-based estimation method is of more practical importance, and the algorithm in this paper does not need iteration computation compared to those unit quaternion-based method proposed by Horn(1987) and Su, et al.

单位四元数表示旋转矩阵时不存在奇异点，故基于单位四元数的运动估计方法具有更大的实用价值，而本文算法无需Horn(1987)和Su等人(1989)提出的单位四元数方法的迭代运算。

With Bobby Abreu, Johnny Damon and Hideki Matsui, the Yanks have three durable All-Star-level outfielders. So it already is going to be difficult to play fourth outfielder Melky Cabrera, much less a fifth outfielder such as Williams, who has no value as a defensive replacement or pinch-runner, and admittedly hates to pinch-hit.

有Bobby Abreu， Johnny Damon和Hideki Matsui三位可靠的明星级外野手在阵中，就连身为第四外野手的Melky Cabrera恐怕也没有太多发挥空间，更别提一个非守备功能性球员，也无代跑能力，甚至还承认自己痛恨担任代打角色的第五外野手了

This paper adopts new algebra structure of quaternion matrix,to study how to apply a variety of iterative algorithm to quaternion linear systems.

本文通过引入四元数矩阵的新代数结构表示运算，研究如何将多种迭代算法应用于四元数线性系统上。

In the forth chapter, the convergence problem of three Ishikawa and modified three Ishikawa iterative sequences under uniformly continuousΦ-strongly pseudo-contractive mapping and approximating pseudo-contractive mapping is

第四章主要讨论了三重迭代序列以及修改了的三重迭代序列在一致连续的Φ-强伪压缩映射、渐近伪压缩映象下的收敛问题，给出了其判别准则和结论描述。

The results showed that under 200 W power, in the present of various alkalis, e.g. Na2CO3, NaF, KF, NaHCO3, and DMF-H2O (V∶V=5∶3) used as solvent, PVC-TETA-Pd could catalyze sodium tetraphenylborate to react quantificationally with iodobenzene in 20 min without inert gas protection, and all the phenyl g...

实验发现：在微波功率为200W时，在Na2CO3，NaF，KF，NaHCO3等多种碱的存在下，以DMF的水溶液(V∶V=5∶3)为溶剂，在无惰性气体保护下，PVC-TETA-Pd催化四苯硼钠与碘代苯在20min内即可定量反应，与常规加热方式相比，节省了大量时间；同时也证明了四苯硼钠的四个苯基均可参与Suzuki偶联反应；该催化剂回收再利用3次后，仍具有较高的催化活性。

A four-ball tester was used to evaluate the load carrying and antiwear properties of bismuth dibutyldithiocarbamate,bis-dibutyldithiocarbamates(V7723),sulfurized isobutylene,molybdenum ester non sulfur and phosphorus in a mineral oil respectively and their synergistic effects.

利用四球试验机评价了二丁基二硫代氨基甲酸铋与二丁基二硫代氨基甲酸酯(V7723)、硫化异丁烯和非硫磷钼酸酯添加剂的极压和抗磨性能，以及它们之间的极压和抗磨协同作用。

Its reaction with ketenes generated in situ from acid chlorides afforded-4--azetidin-2-one, thus provided a 14-member library of-4--azetidin-2-one with yields 76～91% and an excellent stereoselectivity.

我们从PEG支载的苯甲醛出发，经腙的制备及其氯代之后，在三辛胺作用下，由氯代腙原位生成的腈亚胺与亚胺发生[3+2]偶极环加成反应，得到PEG支载四芳基-4，5-二氢-1，2，4-三氮唑衍生物。

Now the sons of Issachar were four: Tola, Puah, Jashub and Shimron.

代上7：1 以萨迦的儿子是陀拉、普瓦、雅述、〔雅述在创世记第四十六章十三节作约伯〕伸仑、共四人。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。