二氧化氮

A highly effective and efficient phosphorus-free, nitrogen-free and biodegradable sequestering agents and detergency builders Polyepoxysuccinic acid was synthesized through negative ion synthesis.

以顺丁烯二酸酐为原料，通过环氧化反应和阴离子聚合的方法，合成了一种无磷、非氮、生物降解性好的环保型阻垢剂聚环氧琥珀酸。

In this dissertation, preparation of polysubstituted ethene and heterocyclic compounds based on 2-hydroxyalkyl phenyl selenides andα-phenylselenopropionic acid reagents were further investigated as follow: Firstly, O-ethyl-O-vinyl phosphonates were prepared in a one-pot, two-step transformation by Mitsunobu reaction of 2-hydroxyalkyl phenyl selenides with monoethyl esters of phosphonic acid in the presence of diethyl azodicarboxylate and triphenyl phosphine (PPh3) followed by oxidation-eliminatio...

中文摘要：本文主要进一步探索了2-羟基烷基苯基硒醚、α-苯硒基丙酸试剂在制备多取代乙烯和杂环化合物反应中的应用，具体研究内容和结果如下：一、在偶氮二羧酸乙酯和三苯膦(PPh3)存在下，苯基-2-羟基烷基硒醚和O-乙基膦酸单酯发生Mitsunobu反应，无需分离和纯化反应中间体，直接使用30 %的双氧水进行氧化-消除反应，提供了&两步、一锅&合成O-乙基-O-乙烯基膦酸酯的新方法，该方法反应条件温和，操作简便，产物收率良好(76-82 %)。

Governments around the world are battling to cut the amountof greenhouse gases - carbon dioxide, methane, nitrous oxide and fluorocarbons - that are being pumped into the atmosphere.

世界各国政府都在争相减少排放至大气中的二氧化碳、甲烷、一氧化二氮和碳氟化合物等温室气体。

The research emphasis is restartable nitrous oxide monopropellant thruster suitable for keeping the position and phase of small satellite.

研究重点是可多次启动的一氧化二氮单元推进剂推力室，适用于小卫星的位置保持和相位保持。

In fact,"we found that if you look ahead, nitrous oxide will remain the largest ozone-depleting emissions for the rest of the century," says A.R.

事实上，&我们发现，如果预测将来，一氧化二氮将会是本世纪最大的使臭氧大大减少的排放物&，美国国家海洋和大气局领导此项研究的 A.R。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失