二酸

Four extracting agents for Lanthanides/Actinides separation , dialkyldithiophosphinic acids, were synthesized from PSCl3 and alkyl halide by Grignard reaction, sulfuration and acidification.

以PSCl3和卤代烷为原料，经格氏反应、硫化和酸化合成了用于镧/锕分离的4个萃取剂——二烷基二硫代次膦酸，其结构经NMR，IR和MS表征。

The application techniques and control of new quinclorac to E. crusgalli in paddy fields were investigated. The results indicated that paddy phytotoxicity was arose by new quinclorac. The application techniques of new quinclorac which had the advantage of adequateness, high efficiency and safety and control efficacy were analyzed.

在新型二氯喹啉酸控制稻田稗草的试验及示范推广中，发现该药剂对水稻有一定的药害，分析了药害的产生原因，提出了适量、高效、安全使用新型二氯喹啉酸的方法。

Disodium 5'-guanylate heptahydrate (5'-GMPNa2) is an important food additive and medicine material, which belongs to the second-generation fresh reagents. 5'-GMPNa2 exists in two solid forms: amorphism and crystal.

5'-鸟苷酸二钠是一种重要的食品添加剂及医药用品，属于第二代鲜味剂。5'-鸟苷酸二钠以无定形体和晶体两种固体状态存在。

Pretreatment of arsenical refractory gold concentrate - Leaching by sodium dichromate ;2. The solution of sulfuric acid was added dropwise to the reaction vessel contained 1,3-dichloro-2-propanol, sodium dichromate and water.

将硫酸水溶液滴加到1，3-二氯-2-丙醇与重铬酸钠水溶液的混合物中，在温度23~27℃的条件下搅拌反应5 h，重铬酸钠∶1，3-二氯-2-丙醇=1∶2，此条件下收率为79。

Any of a group of five chemically related nonmetallic elements including fluorine, chlorine, bromine, iodine, and astatine.

酰亚胺源自氨的一种化合物，含有与一个二价酸基或者二个一价的酸基结合的氨基

The effects of sodium laurylsulfonate and butanol on upper critical solution temperature s for water-phenol were studied by means of cloud point.

浊点法研究了十二烷基磺酸钠和正丁醇对水-苯酚系统上临界溶解温度的影响，结果发现在试验的浓度范围内，该系统的上临界溶解温度随十二烷基磺酸钠质量分数的增大而线性下降。

Examples of humectants include lactic acid, urea (the urea found in creams is synthetically produced by combining one molecule of carbon dioxide with two molecules of ammonia and not obtained from urine), hyaluronic acid (able to retain 1000 times its weight of water), propylene glycol, glycerin, sorbitol, gelatin, lecithin, sodium pyrrolidone carboxylic acid, and butylene glycol.

常见的湿润剂有乳酸，尿素（面霜里的尿素来自于二氧化碳和氨分子的合成而不是从尿中提取的），透明质酸（能保持自身成分1000倍的水分），丙二醇，丙三醇，山梨糖醇，明胶，卵磷脂，吡咯钠，羧基酸和丁二醇。

Results showed that there was significant correlation between the two assays with catechol and tyrosine as substrate respectively.

结果表明，以邻苯二酚和酪氨酸为底物所测PPO活性极显著相关，邻苯二酚所测活性强，但酪氨酸所测活性的变异系数大。

The conversion of eicosapentaenoicacid esters in Chlorella USTB-01 and the formation as well as extraction of EPA were investigated in this paper.

对小球藻USTB-01细胞中二十碳五烯酸酯的转化和二十碳五烯酸的生成与提取进行了研究。

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 %)。

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。