查询词典 first-order reaction

After the completion of reaction, ether is added to the resulting mixture to precipitate the tartrate and filter to recover the ligand. The recovered ligands keep good enantioselectivity only in first recycle, but compared with solution-phase of tartrate counterpart, using of soluble polymer-supported tartrates largely simplifies the workup of sharpless epoxidation.

反应完成后，向反应体系中加入乙醚使配体沉淀，过滤即可回收配体，虽然回收的配体只在第一次循环中保持了较好的对映选择性，但与使用小分子酒石酸酯配体相比，使用可溶性聚合物支载的酒石酸酯极大地简化了Sharpless环氧化反应的后处理。

They can be symptoms, in which case your first reaction is to try to "cure" them with all sorts of pills and syrups.

它们可能是一种象征，这种象征首先可能使你第一反应就是想用所以的药片和糖浆来&治好&它们。

The millimetersized tubular crystal selenium was first prepared. By studying the process of treating selenium in ethylenediamine, we proposed the mechanism of the preparation of selenides under solvothermal condition. The selenides came into being from the reaction of metal ions with Se〓, which was obtained by the amine attacking selenium. Moreover, a new precursor to prepare nanocrystalline selenides at room temperature was obtained. From this precursor, we have prepared nanocrystalline silver selenides, copper selenides, lead selenides and cadmium selenides nanorods.

首次报道了采用溶剂热处理的方法制备出厘米尺度的管状结构硒晶体；通过对硒粉在乙二胺中的溶剂热研究，初步探讨了以单质硒为硒源的溶剂热合成硒化物的反应机理应是硒受胺类的亲核进攻变成Se〓而进一步形成相应的硒化物；获得了合成硒化物纳米晶的前驱物，并在室温条件下合成了硒化银、硒化铜、硒化铅纳米晶和硒化镉纳米棒等。

Ruyan news, my first reaction was as if in the eyes of the Shang Ma hot pepper oil, pain and choking.

消息入眼，我的第一个反应仿佛被人在眼皮上抹了辣椒油，呛而且痛。

Results The activity, recovery rate of activity and half-life of immobilized SOD were 333 U/g, 86.32% and 43.8 d respectively. After storage at room temperature for 5 d, the relative activity of SOD was still more than 80%. The optimal reaction temperature of immobilized SOD was 45℃, and the activity retentions after being used for the first and second times were 70.12% and 51.72% respectively. Both the optimal pH values for SOD before and after immobilization were 6, while the Km values were 0.16 and 0.18 mmol/L respectively.

结果 固定化超氧化物歧化酶活力为333U/g，酶活回收率为86.32%，半衰期为43.8d；固定化酶室温保存5d后，相对酶活力仍保持在80%以上，最适反应温度为45℃，使用一次后回收率为70.12%，重复使用两次后回收率为51.72%；固定化酶与溶液酶在pH6时活性最强，Km分别为0.18mmol/L和0.16mmol/L。

The cross-coupling reaction of DOPO with halogenated phenols were achieved for the first time, novel phenolic hydroxyl-containing reactive-type DOPO-based flame retardants used in epoxy resins were synthesized; the cross-coupling reactions of 2\'-hydroxybiphenyl-2-ylphosphinic acid or diphenyl phosphine oxide with halogenated phenols were studied according to the above result, new reactive-type flame retardants used in epoxy resins were synthesized.

采用Pd催化的方法首次实现了DOPO与卤代酚的交叉偶联，合成了新型含酚羟基的反应型DOPO基环氧树脂阻燃剂；在此基础上实现了2-(2-羟基苯基)苯基次磷酸和二苯基氧化膦与卤代酚的偶联，合成了新型反应型有机磷环氧树脂阻燃剂。

The experimental results show that the optimum conditions were as follows: molar ratio of pentaerythritol to phosphorus trichloride to bisphenol A was 1.0:2.8:2.0, the first and the second reaction held for about 3 h on the conditions of refluxing.

试验结果表明：反应溶剂为苯，用量为50 mL；物料配比〔m：m：m〕为1.0：2.8：2.0；第一步和第二步均回流反应3h。

Based on three hypotheses, the single reaction model was used for the calculation of active energies during pyrolyzing of HBs (except OH-π) in coal for the first time, and the values agreed well with those obtained with other methods.

在三条假设的基础上，采用单一反应模型的理论，研究了煤中除OH-π以外的其它氢键热分解的活化能，通过该方法计算的氢键的热解活化能与通过其它途径得到的值接近

The diagnosis was confirmed by polymerase chain reaction during the first week of their hospital stay.

这个诊断在入院后的第一周经PCR确诊。

An important intermidiate 2-butyl-4-chloro-5-(4-bromomethyl phenoxy) pyridazinone 3 was first obtained from 4,5-dichloropyridazinone using two different methods. Compounds 4a～4l were synthesized by the reaction of 3 with different oximes.

从2-叔丁基-4，5-二氯哒嗪酮出发，以两种方法合成了中间体2-叔丁基-4-氯-5-(4-溴甲基苯氧)哒嗪酮(3)。3与肟反应合成了含哒嗪酮的苄基肟醚类化合物4a～4l。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。