酸酐

On the NiO/SiO〓 catalyst prepared by IM, the main hydrogenation product of MA was SA, the activity and selectivity were almost no relation with the nickel content and nickel species 3. Summarizing the characterization and activity evaluation of the catalysts, we concluded: On nickel based catalyst, when NiO was crystallite, and the Ni〓 that was prepared by reducing, hydrogenation of the MA could lead to SA but not to γ-BL; when NiO was cluster and had a properly interaction with the support, the Ni〓 prepared by reducing, could hydrogenate MA to SA then to γ-BL. When NiO cluster and crystallite were both existed on the catalyst, the hydrogenation products were mixture of SA and γ-BL, and the amounts of SA and γ-BL were related with the ratio of cluster and crystallite.

综合催化剂的表征和活性评价得出：当镍基催化剂上氧化镍以结晶态存在，经氢还原后的零价镍可使顺丁烯二酸酐加氢得到丁二酸酐，丁二酸酐难以进一步加氢为γ-丁内酯；当镍基催化剂上氧化镍以簇团形式存在，与载体之间有适当的相互作用时，经氢还原后的零价镍可使顺丁烯二酸酐加氢得到的丁二酸酐进一步加氢为γ-丁内酯；若催化剂上氧化镍既有结晶态又有簇团形式时，随二者含量比例不同而得到丁二酸酐和γ-丁内酯的混合物。

Chromic trioxide and chromium hemitrioxide are determined with iodometry, the coefficient of variation of chromic trioxide is 0.056%, and the recovery of marked compound is 99.82-99.83%; the coefficient of variation of chromium hemitrioxide is 1.45%,and the recovery of marked compound is 98.55-99.26%; iron is determined by complexometric titration, the coefficient of variation of iron is 1.73%, and the recovery of marked compound is 99.12-99.23%;sulfate is determined by complexometric titration, the coefficient of variation of sulphate is 0.16%, and the recovery of marked compound is

Analysis Of The Chromium Electroplating Wastewater By Oxidation-reduction And Complexometric Titration-化学工程与工艺-本文采用氧化还原滴定法与络合滴定法对镀六价铬的废水中铬酸酐，三氧化二铬，铁和硫酸根的含量进行了测定：铬酸酐和三氧化二铬用碘量法测定，铬酸酐的变异系数为0.056%，加标回收率为99.82-99.83%，三氧化二铬的变异系数为1.45%，加标回收率为98.55-99.26%；铁用络合滴定法测定，其变异系数为1.73%，加标回收率为99.12-99.23%；硫酸根用络合返滴定法测定，其变异系数为0.16%，加标回收率为

In the paper the effects and main differences of maleic anhydride and acrylic acid in the synthesis of polycarboxylate superplasticizers are analyzed according to their respective characteristics and technical requirements for synthesis.

根据马来酸酐与丙烯酸各自的特性和聚羧酸盐减水剂合成的技术要求，分析了它们在合成过程中的作用和主要差别，并概述了马来酸酐在合成中的应用情况，最后提出了马来酸酐在合成中应用的几点建议。

Hrough copolymerization of styrene with few quantity of methacrylic acid, maleic anhydrate or 4-vinyl pyridine respectively and of butyl methacrylate with maleic anhydrate, the functional groups carboxyl, simple anhydride and pyridyl have been introduced respectively to the chain of PS or PBma.

通过苯乙烯与少量的甲基丙烯酸、马来酸酐或4—乙烯基吡啶的共聚及甲基丙烯酸正丁酯与马来酸酐的共聚，可在聚苯乙烯及聚甲基丙烯酸丁酯链上分别引入功能基因羧基、酸酐基和吡啶基对共聚物进行了红外光谱、酸碱滴定、元素分析、玻璃化转变温度、粘度及紫外光谱的测定。

In this paper the study on optimizing the esterification of cellulose and some character of CAB(the degree of substitution of cellulose, solubility, the thermal properties and molecular weight) was discussed. The mechanism of the esterification of cellulose in butyric acid/ acetic acid/ butyric anhydride which comprises the creation of the acetic butyric anhydride, acetyl cation and butyryl cation was investigated by the study of the effect of the content of the organic acid and anhydride on the degree of acetyl and butyryl substitution of cellulose.

最后本文根据纤维素在丁酸/乙酸/丁酸酐中的酯化反应中有机酸以及酸酐的添加量对最后产物纤维素醋酸丁酸酯中乙酯或者丁酯取代度的影响，提出纤维素在丁酸/乙酸/丁酸酐中的酯化反应经历一个混和酸酐以及乙酰碳正离子、丁酰碳正离子的生成过程。

The one is-2-isopropylidene-3-[1-(3,4-dimethoxyphenyl)ethyl-idene] succinic anhydride, the other is-2-isopropylidene-3-[1-(3,4-methylenedioxyphenyl)- ethylidene] succinic anhydride.

合成了三种苯基俘精酸酐，其中具有给电子基的3-(3，4-二甲氧基苯基)亚乙基(2-亚丙基)丁二酸酐与3-(3，4-亚甲二氧基苯基)亚乙基(2-亚丙基)丁二酸酐是新化合物。

The invention relates to condensation products comprised of cyclic carboxylic acid anhydrides of dicarboxylic acids, tricarboxylic acid anhydrides or tetracarboxylic acid anhydrides and difunctional polyamines, especially polyoxyalkylene amines.

本发明涉及由二元羧酸的环状羧酸酐、三羧酸酐或四羧酸酐和二官能化多胺，特别是聚氧化烯胺制备的缩合产物。

The β-CA of B.napus was located in chloroplast stroma and had the conservative motif Cys-X(subscript n-His-X2-Cys peculiar to β type carbonic anhydrases. In the secondary structure,α-helix, random coil,β-sheet, and β-turn were 39.88%, 39.27%, 16.31%, and 4.53%, respectively. The three-dimensional structure was constructed by homology modeling. The 3-D alignment of β-CA from B.napus and a monomer of β-CA octamer from pea showed that the 3-D structure of β-CA from B.napus could match well with the monomer. The alignment results Implied that β-CA from B.napus was a monomer of the β-CA octamer from B.napus.

预测结果显示，甘蓝型油菜β破酸酐酶是定位于叶绿体基质的蛋白质，具有β类碳酸酐酶所特有的保守性基序Cys-χ-His-χ2-Cys；SOPMA预测二级结构显示α螺旋(39.88%)、随机卷曲(39.27%)、β折叠(16.31%)和β转角(4.53%)；用同源建模法构建了三维结构图；通过VAST矢量比对工具将甘蓝型油菜β碳酸酐酶与模板进行三维结构比对，显示甘蓝型油菜β碳酸酐酶与碗豆β碳酸酐酶同型八聚体中的一个单体很好的匹配，推测甘蓝型油菜β碳酸酐酶全酶也是同型八聚体。

The present paper mainly focused on the phase equilibria and crystallization separation of the multi-component aqueous salt system for cleaner production of chromium trioxide in the electro-synthesis process. And these diagrams of the above system was studied for the first time.

本文研究了该产业链中电催化法生产铬酸酐清洁工艺中多元水盐体系相平衡，首次构筑了体系相图，建立了铬酸酐多元复杂体系的结晶分离方法，为电催化法生产铬酸酐工艺路线的设计及优化提供理论依据，论文的主要内容包括如下几个方面： 1。

In the second part, quantum chemical AM1 methods were employedto theoretically investigate the electronic structures of maleic anhydride in ground- and excited-states. On basis of the frontier orbital theoryand three bonding principles, the possibility of reaction of active α-hydroxysuccinic anhydride carbanion and active α-hydroxy-succinic anhydride radical on polymerization process of MArespectively by alkali catalyst and by hydroxyl radical was discussed. Theanionic and radical polymerization of MA discussed also. Theoreticalstudies show that both polymerization products of MA are in the chainstructures, corresponding to the experimental findings.

第二部分用量子化学AM1方法，计算研究了马来酸酐的基态和激发态电子结构；应用前线轨道理论和成键三原则分别探讨了碱催化条件下和羟基自由基引发下马来酸酐均聚合过程中α-羟基丁二酸酐碳阴离子和α-羟基丁二酸酐碳自由基活性中间体参与反应的可能性及由它们引发的马来酸酐阴离子聚合反应机理和自由基引发聚合反应机理；理论研究表明马来酸酐的均聚合产物均为链式结构，与实验事实相相符。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。