丙烷

As a newtype cleaning agent, 1-bromopropane not only has the same outstanding cleaning effect to CFC-113, but has better cleaning efficiency than it, especially cleaning metal parts. 1-bromopropane has no flash point, it can be repetitive-used, and its craft was complete unification with CFC-113 and TCA. Using 1-bromopropane as a cleaning agent, it is not necessary to replace the cleaning equipment but only adjusting the temperature of distillation and abstersion.

1-溴丙烷(英文名1-bromopropane，简称n-PBr)作为新型的清洗剂，其清洗效果可与CFC-113媲美，且清洗效率比CFC-113高，对于金属零件的清洗能力更强，没有闪点，可以重复回收使用，替代CFC-113和TCA，工艺完全一致，几乎不需要更换设备，只需要调整一下蒸洗温度就可以了，也被称为是"第三世界的替代清洗剂"。

The ring-open nitration of propylene oxide compounds was investigated using dinitrogen pentoxide as nitrating agent.

并以N2O5为硝化剂考察了环氧丙烷类化合物开环硝化过程，探讨了取代基的电子效应和立体效应对环氧丙烷类化合物开环硝化过程的影响规律。

Chiral SalanCrX complexesa saturated version of SalenCr(ⅢX are designed,and in conjunction with an ionic quaternary ammonium salt or organic strong base can efficiently catalyze the asymmetric,regio-and stereoselective alternating copolymerization of CO_2 with rac-PO at mild conditions to afford isotactic-enriched polycarbonates with～95%head-to-tail linkages and moderate enantioselectivity.

本论文在Salen构型配体的基础上，设计合成了一系列手性Salan型铬配合物，并将其与季铵盐/有机强碱组成亲电-亲核双组分催化体系，在室温下可以有效的催化CO_2和环氧丙烷的不对称交替共聚反应，实现了CO_2和环氧丙烷的不对称交替共聚反应的区域和立体化学控制，得到95%的头尾连接单元和中等光学纯度(对映体过量值ee%≈70%)的全同结构的聚碳酸酯。

The distance difference between 6/8/6/4 taxoids and 5/7/6/4 taxoids indicates that the role of oxetane is to form a suitable bow-shaped skeleton with 6/8/6 tricycle.

环氧丙烷结构类型化合物弓形口间距值明显区别于其它三类化合物；5/7/6/4与6/8/6/4类型化合物弓形口距离不同，说明紫杉烷二萜化合物的环氧丙烷结构对活性的作用是和6/8/6三环骨架共同支撑一个合适大小的弓形架。

According to the structure of the diesel locomotives, the author puts forward the possibilities of the application of the HFC-227ea gas fire-extinguishing system, and analyses its difficulties and solving methods.

从铁路内燃机车的火灾危险性分析着手，根据内燃机车的结构和环境特点，提出了七氟丙烷灭火系统应用的可行性，并分析研究了应用中的难点和解决方案，通过模拟试验验证了七氟丙烷系统在气流交换量较大的列车上使用的可行性并基本适宜在机车上采

Thus iron tetrakis porphyrin chloride , chosen as a catalyst in this study, was synthesized, and its solubility and catalytic activity in supercritical propane were investigated.

本研究选择多卤代卟啉铁作为催化剂，合成了四卟啉氯化铁，测定了TPFPPFeCl在超临界丙烷中的溶解度，并且考察了利用空气选择性羟基化丙烷的催化行为。

These catalysts were employed in the HKR of epichlorohydrin, styrene oxide and phenyl glycidyl ether.

研究了其对环氧苯乙烷、环氧氯丙烷以及苯氧基环氧丙烷等的水解动力学拆分的催化作用。

Under distillation conditions, including a bottoms temperature of greater than about 55 DEG C and less than about 75 DEG C, an overhead or side-cut distillate stream containing a purified propylene oxide is obtained with low yield loss of propylene oxide to propylene glycols and other glycol heavies.

在包括大于大约55℃且小于大约75℃底部温度的蒸馏条件下，得到含有纯环氧丙烷的塔顶馏分流或侧馏分流且具有低的从环氧丙烷转化到丙二醇和其他二醇重质的产率损失。

In the experimentation, the premixed propane-air flame propagation behavior was studied as the following:(1) Study on pressure wave influence on premixed propane-air flame propagation behavior under different pressure relief case The high speed Schlieren photograph method was used to record the dynamic process of flame propagation clearly, including the precise flame front position, flame structure, and so on.

实验过程中，首先利用预混火焰精细实验台对丙烷-空气预混火焰的传播特性进行了实验研究：(1)重点研究了不同泄压条件下的压力波对丙烷-空气预混火焰传播特性的影响。

Group A = atmospheres containing acetylene; Group B = atmospheres containing hydrogen; Group C = atmosphere containing ethyl-ether vapors, ethylene, or cyclopropane; Group D = atmospheres containing gasoline, hexane, naphtha, benzene, butane, propane, alcohol, acetone, benzol, lacquer, solvent vapors or natural gas.

组A =大气中含有乙炔；组B =大气中含有氢；组C =大气中含有乙醚蒸汽，乙烯，或环丙烷；组D =大气中含有汽油，乙烷，石脑油，苯，丁烷，丙烷，酒精，丙酮，不纯苯，漆，溶剂蒸汽，或天然气。

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％。