查询词典 condensation

First, the precursor polymer with azobenzene groups on main-chain was obtained by condensation polymerization between 4,4'-dihydroxyazobenzene and N,N-(2-bromoethyl)aniline through Williamson reaction. Then the azo polymer containing azobenzene groups both on main-chain and side-chain was prepared through an azo-coupling reaction between the precursor polymer and the diazonium salt of 4-nitroaniline.

设计并合成了一种新型的主侧链均含偶氮生色团的聚合物，首先通过4，4'-二羟基偶氮苯与N，N-二溴乙基苯胺之间的Williamson反应缩聚得到主链含偶氮苯基团的先驱聚合物，再通过重氮偶合反应得到目标产物，并利用核磁共振、红外光谱、紫外可见光谱、热分析等手段确认了所制备聚合物的结构。

Two kinds of di aniline derivative s connected with oxamethylene bridge or azamethylene bridge were synthesizied by condensation of o nitrophenol and ethylene dibromide (1,4 dibromobutane)or 4 chloro 3,5 dinitrobenzotyifluoride and ethylene diamine(1,6 hexandiamine)and consequent reduction.

由邻硝基苯酚和二溴乙烷以及由4－氯－3， 5－二硝基三氟甲苯和乙二胺为原料通过桥接、还原合成两类由氧亚甲基或氮亚甲基桥联的双苯胺衍生物。

In the example of condensation refrigeration system, the constraint relation was built according to qualitative difference equation.

在压缩制冷系统实例中，根据制冷系统的定性微分方程建立约束关系。

The protection system against condensation is activated by a digital switch channel.

防冷凝的保护系统可通过一个数字开关通道激活。

In this paper, Claisen condensation of isochroman ?4?one as starting material with diethyl oxalate is carried out to form β?diketone compound of isochroman ?4?one.

以异色满酮 4为起始原料，经Claisen缩合得其β二酮衍生物，再与水合肼进行Knorr反应环合成 3 乙氧甲酰基和 3 肼甲酰基异色满并吡唑衍生物，通过酰肼与糠醛反应成腙后，分别与巯基乙酸和氯乙酰氯反应合成了标题化合物

Polyesters are produced by a condensation reaction of a diol, such as ethylene glycol, with a dicarboxylic acid.

聚酯是由一缩合一二醇，例如乙二醇，以二元酸。

The synthesis of diphenylamine from aniline-phenol by liquid phase condensation in the presence of Pd/C catalyst was studied.

研究了在Pd／C催化剂存在下，通过液／固催化缩合反应由苯胺和苯酚合成二苯胺的方法。

Results indicates,these six kinds of naphthalene sulfonic acidformaldehyde condensation product quaternary ammonium salts have excellent dispersiveness,as well as water-reducing and strength-increasing abilities.

前期研究结果表明：混凝土聚合物型外加剂中金属离子的改变对其性能有较大影响。与金属离子相比，季铵阳离子在分子结构、空间体积、亲水性等方面具有更大的可变性。

Opening a bucket down a hole when a part of the steam discharged from the holes and the other part of theREDUCING VALVES condensation of water vapor generation inverted bucket to lose buoyancy by its own weight goes down inverted bucket connecting lever to open the valve spool driven cycle work intermittent drainage.

倒吊桶上开有一小孔，当一部份蒸汽从小孔排出，另一部份蒸汽产生凝结水，倒吊桶失去浮力，靠自身重量向下沉，倒吊桶连接杠杆带动阀芯开启阀门，循环工作，间断排水。

The water condensation system is mainly for delivery of water to the low-pressure fuel economizer of the hrsg through the condensing water pump.

1.1.10。凝结水系统凝结水系统主要作用是通过凝结水泵向余热锅炉的低压省煤器输送给水。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷