查询词典 catalyst

By analyzing the differences between acidic and basic catalytic action in this transesterificatios, it is considered that the main cause of yielding an anisole by-product is due to the basic catalysis, a Lewis acidic catalyst is helpful for the selective DPC formation.

通过分析酸碱催化作用在酯交换反应中的差异，认为碱催化是副产物苯甲醚生成的主要原因，Lewis酸性的催化剂有利于碳酸二苯酯的高选择性。

The more active catalyst and the more suitable carrier should be selected further not only to heighten the yield of MPC and DPC,but to avoid the production of anisole at above 250℃.

由此可以知道，要想使得MPC、DPC产率增加需选择更适合的催化剂，而对于高温下气固相反应应该选择更适合的能有效抑制苯甲醚副反应发生的催化剂载体。

In the acylation reaction between anisole with acetyl chloride, The catalyst of ZnCl〓/HY-98 prepared by MWI had the best catalytic activity and the selectivity of p-methoxy acetopheone. The catalytic active centers were ZnCl〓 dispersed in zeolite and the Bronsted acid sites in HY-98 zeolite itself.

在苯甲醚与乙酰氯的酰化反应中，微波固相法制备的ZnCl〓／Y催化剂有相对较好的催化活性和选择性，起催化作用的主要是分散在分子筛表面的ZnCl〓和分子筛本身的B酸。

However, some problems, such as low electrocatalytic activity of the anodic catalyst restrict its practical use.

然而，阳极催化剂的低催化活性等问题限制了DMFC的实际应用。

Anodic catalyst is one of the key materials in DMFC.

纳米电催化剂是燃料电池中的关键材料之一。

However, the low electro-catalytic activity of anodic catalyst restrict its practical use.

但是，阳极催化剂的低活性限制了DMFC的实际应用。

Deuteration of anthracene using MoCl5 as a catalyst proceeded within 24 h at room temperature.

MoCl5催化的蒽的氢氘交换反应在室温下24小时完成。

The effect of Ca-Fe-Ce series catalyst on the characteristics of anthracite combustion was investigated by thermo-gravimetric analysis.

利用热天平研究了Ca-Fe-Ce系催化剂对无烟煤燃烧特性的影响。

Antimony trioxide (Sb2O3) is a catalyst that is often used in the production of PET.

水的锑含量在 PET瓶里是有高些的，但在允许的最高浓度内。

The major catalyst for this transformation was the rise of a powerful antislavery movement that expanded and strengthened during the Revolutionary Era both in Europe and in the United States.

这一轉 变的主要催发因素是一场在革命时期蔓延，并壮大到欧洲和美国的强大的反奴隶运动。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。