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《精细化工经济与技术信息》2004,(3):4-5
三氯蔗糖,又名三氯丰乳蔗糖,简称TGS,外观为白色或近白色结晶粉末,几乎无臭、无吸湿性、低热值、热稳定性高,甜度为蔗糖的600倍,甜味品质好,对光、热、pH值均很稳定,极易溶于水、乙醇和甲醇,微溶于乙酸乙酯。三氯蔗糖的合成是以蔗糖为原料,主要有基团迁移 相似文献
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本文主要研究了二(三氯甲基)碳酸酯代替气态光气合成1,5-萘二异氰酸酯工艺,考察了物料配比、催化剂对反应的影响,并对合成工艺进行了优化。 相似文献
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锅炉的停用腐蚀较运行腐蚀的危害更大,锅炉在停用期间,特别是停炉1年以上的锅炉,给出充氮保护法、二甲基酮肟保护法、联氨保护法、气相缓蚀剂保护法和成膜胺保护法的特点和具体应用情况。建议实施停炉保护时,根据实际情况选择合适的方法。 相似文献
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卡巴拉汀是氨基甲酸类乙酰胆碱酯酶抑制剂,用于治疗阿尔茨海默症,市场空间大。文章对卡巴拉汀合成路线进行了详细梳理,分为外消旋体的化学拆分方法和不对称合成法,其中化学拆分法是对终产物卡巴拉汀的外消旋体进行拆分,或对合成中间体的外消旋体进行拆分,不对称合成法主要在于手性中间体化合物的合成。 相似文献
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改善腈纶亲水性的方法有化学改性和物理改性两种。前者主要通过在聚丙烯腈大分子链中引入亲水基团,或与亲水性物质进行接枝共聚,对纤维表面进行碱减量处理;后者主要通过与亲水性物质共混和复合,使纤维结构微孔化、截面异形化和表面粗糙化。文章综述了国内外改善腈纶亲水性的研究进展,介绍了亲水性腈纶的应用。 相似文献
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目前矿山废水大部分都没有经过处理而直接外排,造成附近水体及环境严重污染.为了保护水资源和矿区环境,必须采取有效的技术措施,使矿山废水净化、复用,以保护短缺的水资源和矿区生活环境. 相似文献
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金属-有机骨架材料(简称MOFs)是近年来发展迅猛的一种具有三维孔结构的新型高分子材料,由有机配体和金属离子通过配位键自组装形成,具有较大的比表面积和较好的吸附性能。回顾了MOFs材料的研发历程,系统地介绍了MOFs材料水/溶剂热合成、微波合成、超声合成的原理和制备方法,分析了其优点和存在的不足。讨论了MOFs材料在储氢、CO2吸附、有毒化合物吸附、催化、荧光等方面的研究进展,认为未来的研究方向是开发新的MOFs材料合成工艺,进一步提高结构稳定性,拓展其应用领域。 相似文献
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The certification test standards that presently exist for flame arresters are highly inadequate for inline applications. A proper flame arrester test method should ensure that a unit will work with any flame front conditions that it could be exposed to in actual use. When evaluating flame arrester performance, it is just as dangerous to neglect deflagration testing as detonation testing. The comprehensive inline flame arrester test method outlined here involves exposing a unit to the entire flame propagation pressure spectrum. This includes low, medium and high pressure deflagrations as well as overdriven and stable detonations. The test method also takes into account the following factors: flow restriction on the protected side of the flame arrester, flame propagation through a flowing gas, initial system pressure and temperature, and specified gas mixture. Flow restriction on the protected side of the flame arrester has a very significant effect on performance and has not previously been given consideration in flame arrester testing. Besides moving flame front test, endurance burn testing and hydrostatic pressure testing are also discussed here. Major regulatory organizations have recently adopted these findings as the basis for new standards proposed to cover an inline flame arrester test method. 相似文献
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Previous research has suggested that low share market businesses have dismal prospects. This study examines low share businesses which are effective. In particular, it examines the product-market choices and competitive strategies of effective low share businesses, comparing them with two control groups: effective high share and ineffective low share businesses. Data are drawn from PIMS data bases and hypotheses are tested using cluster analysis and discriminant analysis. Effective low share businesses are found to locate in stable rather than protected environments. Their competitive strategies are strongly characterized by selective focus on specific strengths. 相似文献
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