查询词典 first-order reaction

The oxidation of solid biurea with chlorine in aqueous solution to produce azodicarbonamide was experimentally studied in a 1 L agitated glass vessel with a four-blade paddle stirrer. Based on the film theory, a model is first developed for this system by taking the gas-liquid and solid-liquid mass transfer, solid dissolution, and instantaneous reaction between the dissolved reactants into consideration.

在玻璃搅拌反应器中进行了固体联二脲与氯气液相氧化反应生成发泡剂 ADC过程的传质与动力学实验，提出了基于双膜理论的数学模型，以描述这一反应系统所涉及的气液和固液传质、固体溶解以及溶解物在液相中发生瞬间反应，特别是随反应进行固体反应物粒径变小导致固液传质速率减小的复杂过程。

SO〓〓/M〓O〓 solid superacid was applied to the photocatalytic oxidation of organic pollutants for the first time. Porous SO〓〓/TiO〓 solid superacid catalysts with high specific surface area were prepared by sol-gel method. The photocatalytic degradation of bromomethane was used as model reaction. The influence of impregnation with H〓SO〓 solution on the structure of catalysts and their photocatalytic performance was systematically studied by using X-ray diffraction, X-ray photoelectron spectroscopy, N〓 sorption analysis applying BET method, UV-Vis diffuse reflectance spectroscopy, FTIR spectroscopy, O〓-TPD and photocatalytic activity measurement. The acidity of TiO〓-based catalysts was investigated by Hammett indicator method, NH〓-TPD and IR spectra of pyridine adsorbtion. The mechanism of superacidifing effects on photocatalytic performances such as the photocatalytic degradation rate of bromomethane, apparent kinetic constant and apparent quantum efficiency was discussed.The results indicated that SO〓〓 is combined with metal ions of TiO〓 in a chelating bidentate mode.

本文首次将SO〓〓/MxOy型固体超强酸催化剂用于光催化氧化有机污染物研究，采用溶胶-凝胶法制备了具有多孔性和大比表面结构的二氧化钛基固体超强酸光催化剂SO〓〓/TiO〓，以光催化降解溴代甲烷为模型反应，系统地研究了H〓SO〓浸渍处理对催化剂表面酸性及其气相光催化性能的影响，结合XRD、BET、XPS、FTIR、Hammett指示剂法、吡啶吸附红外光谱、NH〓-TPD、O〓-TPD、紫外可见漫反射光谱等多种表征手段，深入地讨论了超强酸化对TiO〓的改性机理，阐明了引起SO〓〓/TiO〓超强酸催化剂光催化降解溴代甲烷的转化率、表观反应速率常数和表观量子效率变化的本质原因。

Posttourniquet syndrome, as first recognized by Bunnell[1], is a common reaction to prolonged ischemia and is characterized by edema, pallor, joint stiffness, motor weakness, and subjective numbness. This complication is thought to be related to the duration of ischemia and not to the mechanical effect of the tourniquet. Sapega[2] et al.

止血带综合征首先由Bunnell[1]认识，是肢体对长时间缺血的共同反应，表现为水肿、苍白、关节僵硬、运动无力以及主观感觉麻木，被认为与缺血持续时间有关，而与止血带的机械作用无关。

Posttourniquet syndrome, as first recognized by Bunnell[1], is a common reaction to prolonged ischemia and is characterized by edema, pallor, joint stiffness, motor weakness, and subjectie numbness. This complication is thought to be related to the duration of ischemia and not to the mechanical effect of the tourniquet. Sapega[2] et al.

止血带综合征首先由Bunnell[1]认识，是肢体对长时间缺血的共同反应，表现为水肿、苍白、关节僵硬、运动无力以及主观感觉麻木，被认为与缺血持续时间有关，而与止血带的机械作用无关。

He first synthesis of the precursor 45b of Tuxpanolide was accomplished fromβ-alkoxy aldehyde and β-acetoxy-γ-butyrolactone by the Aldol reaction.

uxpanolide的合成前体45b的首次不对称合成：以β-烷氧基开链醛和β-乙酰氧基-γ-丁内酯参与的Aldol醛醇缩合反应首次得到了前体化合物45b。

The first samples were made through a nuclear reaction involving fusion of an isotope of californium, 249 Cf, with one of oxygen, 18 O.

第一样品透过核反应涉及融合的一个同位素锎，249酸钙，其中氧，18澳。

At first, the best synthetic conditions have been achieved by orthogonal experiment according to one step reaction of perfluoro caprylic acid and a kind of aminofunctional siloxane.

应用IR谱图对氨基硅油和全氟辛酸的分子结构进行了测定；通过各反应前后原料与生成物的IR谱图对比以及~1H NMR，明确反应进展情况和产物的各特征峰。

DFA-PEG polyester was synthesized with DFA and PEG 400 at first, and then bysulfating DFA-PEG polyester with NH_2SO_3H or terminating DFA-EG polyester withrosin acid, two derivant, these are sulfated DFA-PEG polyester and terminateDFA-PEG polyester, were synthesized. The reaction conditions of synthesis wereoptimized by orthogonal experiments.The molecular weight of product was analyzed by GPC.

5以二聚脂肪酸和聚乙二醇400为原料，首先合成了DFA-PEG聚酯，再以DFA-PEG聚酯为衍生体，硫酸化或用松香封端，合成了两种DFA-PEG聚酯衍生物——DFA-PEG聚酯硫酸酯盐和松香酸封端DFA-PEG聚酯，通过正交试验，对合成的条件进行了优化。

Three aspects were included here:The derivatives of dihydrol,2,4,5-tetrazine-3,5-dicarboxylic acid were synthesized via three different routes:(1) four new compounds were synthesized via the reaction bet ween dihydrol,2,4,5-tetrazine-3,5-dicarboxylic acid, thionyl chloride and corresponding alcohol ;(2) first ,dimethyl dihydro-1,2,4,5-tetrazine-3,5-dicarboxylate wer e synthesized, then ,another four new compounds were obtained t hrough the alcoholysis under the catalyst ;(3) three acylamines were got through the ammonolysis betw een dimethyl dihydro-1,2,4,5-tetrazine-3,5-dicarboxylate and amines.

本论文分别通过三条不同的路线合成了1，4-二氢-3，6-二甲酸-s-四嗪的衍生物：(1)通过1，4-二氢-3，6-二甲酸-s-四嗪与氯化亚砜和相应的醇反应，制备了四个新化合物；(2)合成1，4-二氢-3，6-二甲酸甲酯-s-四嗪，在催化剂的作用下，与高沸点的醇进行酯交换反应，合成了四个新化合物；(3)合成1，4-二氢-3，6-二甲酸甲酯-s-四嗪后，与胺进行氨解反应，合成三个新的1，4-二氢-3，6-二甲酰胺-s-四嗪化合物。

The first asymmetric synthesis of trans-β-hydroxy-γ-butyrolactones:-(3R, 4R, 5S)-4-(1-acetoxy-isopropyl)-3-hydroxy-butyrolactone 65a was achieved starting from isobutylaldehyde through nine steps. The key steps involve the construction of three chiral carbon centers by the Sharpless's asymmetric epoxidation and Substrate directable chemical reaction.

以异丁醛为起始原料，经过九步反应首次设计合成了具有三个手性中心的trans-β-羟基-γ-丁内酯：-（3R，4〓，5S）-4-（1-乙酰氧基-异丙基）-3-羟基-丁内酯65a，关键步骤是Sharpless不对称环氧化和底物定向不对称合成反应。

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。