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以—水乙醛酸和尿素为原料,对甲基苯磺酸—磷酸构成的复合酸作为催化剂,利用微波辅助加热技术,经环化缩合反应制备了医药和有机合成中间体及日化助剂尿囊素。研究表明,微波辅助加热可以有效地提高反应效率,反应中的微波辐射功率以500-700W为宜;在微波辐射功率为650W时,微波加热反应15min后尿囊素收率可达60%左右,结果相当于普通加热方式加热反应6h的效果。产品经元素分析、熔点测定、红外光谱表征并用滴定法测定其纯度,尿囊素含量在98%以上。 相似文献
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生物催化具有条件温和,效率高,专一性强,副产物少等优点,因此制药工业中采用了很多生物催化剂生产药物。本文对此做了综述。 相似文献
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BST型固体超强酸催化合成萘乙酸甲酯的研究 总被引:1,自引:0,他引:1
BST型固体超强酸(TiO2/SO24)催化合成萘乙酸甲酯最佳反应条件为:n(甲醇)∶n(α-萘乙酸)=10∶1,反应温度65 ℃,反应时间2 h,催化剂用量为α-萘乙酸质量的1%.酯收率大于92%. 相似文献
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BST型固体超强酸(TiO2/SO42-)催化合成萘乙酸甲酯最佳反应条件为:n(甲醇):n(α-萘乙酸)=10:1,反应温度65℃,反应时间2 h,催化剂用量为α-萘乙酸质量的1%,酯收率大于92%. 相似文献
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酸性离子液体催化合成双丙酮丙烯酰胺 总被引:1,自引:0,他引:1
以N-甲基咪唑、2-氯乙基苯、对甲苯磺酸合成1-甲基-3-[α-甲基-(4-磺酸苄基)]咪唑对甲苯磺酸盐酸性离子液体。考察了酸性离子液体在丙酮和丙烯腈的反应中的催化性能,确定了最佳反应条件:n(丙酮):n(丙烯腈)=2.2:1.0,酸性离子液体用量为丙烯腈质量的8.0%,反应温度(40±2)℃,反应时间3.0h.在该条件下双丙酮丙烯酰胺的收率〉61%,且反应结束后产物易于分离,酸性离子液体循环使用5次以上。 相似文献
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用强酸性阳离子交换树脂代替硫酸作催化剂制备三醋酸甘油酯的适宜条件是:醇酸比1:4(摩尔比),催化剂用量约为0.4g(树脂)/mol(乙酸),以苯作为共沸脱水剂,可使三醋酸甘油酯收率达93.5%。 相似文献
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随着移动Ad hoc网络(MANET)的兴起,因其具有广阔的发展空间而受到广泛关注,但现有安全方案都存在局限性.本文基于对MANET的学习从以下几个方面进行讨论:MANET路由安全分析;MANET安全路由协议研究现状的分析和对相关路由协议的总结. 相似文献
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Erja Toiviainen‐Laine Risto Kuisma Hanna‐Riitta Kymäläinen Anna‐Maija Sjöberg 《International Journal of Consumer Studies》2009,33(4):396-406
In many countries, changes in the pattern of working lives and ageing of the population increases the need for professional cleaning in private domestic homes. The objective of this study was to obtain basic knowledge concerning professional home cleaning. The study consisted of two parts. First, cleanability of surfaces contaminated with microbiological and organic soils was examined in the laboratory using cleaning cloths, detergents and rapid detection methods with potential for use in conjunction with professional cleaning in private homes. Second, hygienic conditions in three households were screened using the same rapid detection methods as in the laboratory experiments. According to the laboratory study, the cleaning efficiency of the non‐woven cloth was clearly poorer than that of the cleaning cloths containing microfibers. There were differences between the efficacy of the cleaning agents in removal of protein and microbiological soils. Despite the differences between surface topography observed with scanning electron microscopy, differences between the cleanability of the three examined surface materials (steel and two plastic surfaces) were small. In hygiene monitoring, the highest levels of total aerobic bacterial counts were detected in the plughole of the sink, on the eating table in kitchens and along the edge of the toilet washbowl and the cover of toilet seats. Low amounts of Enterobacteriaceae indicating faecal contamination were detected in the toilet and bathroom after cleaning. Moulds were not detected in any of the three households, and the amounts of yeasts were low. Detection methods, microbiological dipslides and the protein test, were well suited to the laboratory study. Furthermore, they complemented each other in the hygiene monitoring. The information obtained will be used for development of better practices in professional home cleaning. Good quality management in professional home cleaning and the cleanliness of surfaces in homes are important factors affecting comfort and safety. 相似文献
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随着城市的不断发展,人们生活的质量也随之提高,致使城市垃圾大量增加,城市垃圾污染问题也日益严重,垃圾污染已经成为影响我国经济发展的瓶颈,而对于此类问题的法律制度尚属不足;近几年学者都很关注环境风险防范的法律制度问题,而就城市垃圾问题的风险防范制度却很少有人提及。完善我国城市垃圾环境风险防范法律制度应加强城市垃圾环境风险的管理立法;构建城市垃圾风险防范的法律制度;设立城市垃圾风险信息披露制度;提高公众城市垃圾环境风险防范意识。 相似文献