共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
苯甲酸的传统合成工艺是,在一定条件下,用无水碳酸钠和高锰酸钾还原氯化苄,反应液用浓盐酸酸化,再加入亚硫酸钠溶液至二氧化锰沉淀完全溶解,得苯甲酸粗品。粗品用冷水洗涤,用热水重结晶,干燥得纯品。但实践证明,合成时带入的杂质在重结晶过程中难以除去,因此纯化... 相似文献
3.
过硫酸氢钾是一种应用广泛的强氧化剂,但其强氧化活性需要外来的催化剂进行活化。本文首次报道了非晶态二氧化锰(AMO)对过硫酸氢盐的活化氧化过程,研究了该氧化体系降解偶氮染料酸性橙7(AO7)分子的性能。通过XRD、SEM、激光粒度分析仪对制备的悬浮态非晶态二氧化锰进行了表征,发现二氧化锰颗粒在溶液中呈现纳-微二级结构,且具有良好的吸附能力。AO7的氧化脱色实验表明,非晶态二氧化锰AMO比晶体态的α-Mn O2纳米棒具有更好的活化氧化脱色性能,且AO7的脱色过程符合拟一级动力学方程,非晶态二氧化锰的特殊结构和吸附作用加速了氧化脱色过程。AO7溶液的氧化矿化实验表明,在20md/L非晶态二氧化锰存在条件下,AO7在过硫酸氢钾氧化体系的矿化率达到82%,非晶态二氧化锰表现出良好的催化性能。采用高锰酸钾与过硫酸氢钾联合作用,由高锰酸钾产生非晶态二氧化锰,可以实现氧化协同效应。 相似文献
4.
5.
2,3-二氯苯甲酸是合成特效抗癫痫药拉莫三嗪及其它治疗中枢神经紊乱药物的重要中间体。笔者用2,3-二氯苯胺经重氮化、迈尔瓦音反应制得2,3-二氯苯甲醛,再经高锰酸钾氧化制得2,3-二氯苯甲酸,总收率45%。对各步反应的操作及产品的纯化方法进行了研究。 相似文献
6.
7.
8.
9.
综述了国内外高锰酸钾和二氧化锰在各类水处理中的应用及研究进展,包括利用高锰酸钾的氧化性,二氧化锰的吸附、氧化及催化作用处理水中有机、无机及离子型污染物.研究表明,在水处理中,高锰酸钾预氧化是一项高效实用、经济便捷、具有发展潜力的预处理技术,并且高锰酸钾和二氧化锰在水中污染物的去除方面有着显著的优势. 相似文献
10.
11.
乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
12.
13.
14.
The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure. 相似文献
16.
以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。 相似文献
17.
18.
The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
19.
我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
20.