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春节前后,吉安市遭遇到罕见的冰冻雨雪灾害天气,连续出现了低温、阴雨和雨夹雪,成为全省灾情最严重地区之一.特别是1月25日以后,出现了持续大范围的雨雪冰冻天气.冰冻损坏了市区的电网,压垮了树枝,封锁了道路和桥梁. 相似文献
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收集了2010年7月~2011年6月世界塑料工业的相关资料,介绍了2010~2011年世界塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、ABS树脂),工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚),特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮),通用热固性树脂(酚醛、不饱和聚酯树脂、环氧树脂、聚氨酯)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。 相似文献
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萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。 相似文献
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我公司回转窑规格为Φ4.0m×60m.窑内使用的耐火砖为镁铬砖、隔热尖晶石、蓝晶石和黏土砖以及硅莫砖.镁铬砖规格为(81×90×150×200)mm,其它耐火砖规格皆为(81×90×200×200)mm.尽管每个品种的砖品质相同,但由于在镶砌和使用过程中方法不同,寿命有长有短.通过多年实践,现总结如下. 相似文献
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《日用化学品科学》编辑部 《日用化学品科学》2008,31(6)
2006年12月7日~2006年12月8日化妆品化学家年会在美国纽约举行,该年会为化学品供应商提供了参与REACH法规的机会.REACH法规的实施引起了业界的广泛关注,来自世界各地的著名化学品及化妆品公司对REACH法规的实施所带来的一些问题,以及新原料、新技术进行了交流.会议主要对就REACH法规、制造及规模化和神经美容品等方面展开了研讨. 相似文献
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Marco A. Guerreiro Silvio R. Andrietta Francisco Maugeri 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1997,68(2):163-170
A user-friendly expert system was developed for the design of large scale continuous fermentation units for alcohol production. This expert system utilized an intensive rule-based program, with a knowledge base structured using both expert knowledge data and industrial practices, as well as computer simulations. The simulation algorithm was developed from mass and energy conservation of continuous multi-staged plants and kinetic equations representing the fermentation process by Saccharomyces cerevisiae. The kinetic parameters were adapted from industrial data, leading to a reliable mathematical model that represented the industrial process reasonably well. Since the system was designed for continuous processes with several stirred tanks connected in series, the optimal volume profile and number of stages were previously optimized. The system developed could be utilized either for the design of industrial plants or for the improvement and modernization of existing plants. This system was shown to be reliable since the difference between theoretical calculations and practical results was minimal. © 1997 SCI. 相似文献
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电石渣浆代替生石灰用于纯碱蒸氨的工艺方案 总被引:2,自引:0,他引:2
介绍了电石渣浆在氨碱法纯碱生产中代替生石灰用于蒸氨工艺的可行性和初步方案,实验证明该方案是可行的,具有较好的环境效益及经济效益。 相似文献
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刘文杰 《硫磷设计与粉体工程》2003,(4):27-29
合理配置球磨机润滑油站,是使球磨机安全运行和延长其使用寿命的一个重要条件。对以动静压轴承为主轴承的球磨机,采用高、低压稀油对其进行强制润滑。较详细地介绍以这种润滑方式所配置的润滑油站的组成、工作特点、工作原理以及在运行中应注意的一些问题。 相似文献
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D. M. Ottenstein L. A. Witting P. H. Silvis D. J. Hometchko N. Pelick 《Journal of the American Oil Chemists' Society》1984,61(2):390-394
Chromatography has developed into one of the principle methods of analysis of oleochemicals. Gas chromatography has been used
extensively for the analysis of long-chain fatty acids as well as for the analysis of triglycerides and plant sterols. In
recent years, high pressure liquid chromatography (HPLC) has been used for the analysis of triglycerides as well as for other
related materials. Specialized gas chromatography columns have been developed for the separation of long-chain fatty acids
such as the methyl esters. These columns have generally used high polarity stationary phases which separate fatty acids by
degree of unsaturation. A specialized use of these high polarity stationary phases is separation ofcis-trans isomers as well ascis-cis andtrans-trans isomers. In this paper, packed and capillary columns are compared for the separation of thecis-trans isomers of fatty acid methyl esters prepared from a hydrogenated vegetable oil. For HPLC separations, the presence of a double
bond is approximately equivalent chromatographically to shortening the alkyl chain by two carbons. The long-chain polyenic
acids or ethyl esters thus elute near but are resolved from the short-chain saturated fatty acids or esters. HPLC is the method
of choice for relatively complex, high molecular weight, or labile esters, such as those of retinyl or cholesterol. Glyceryl
esters are particularly well resolved by HPLC in terms of both total chain length and degree of unsaturation. This technique
is also useful for lipid class separations and for the analysis of modified fatty acid products, such as prostaglandins and
related materials. In general, these analyses are conducted with octadecyl bonded phase column packings. 相似文献
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以醋酸钴-醋酸铜-醋酸铁为主催化剂,以甲醇为溶剂。以氧气为氧化剂,经过氧化、蒸馏、酸化等过程。形成了用对甲酚氧化制备含量99.5%以上的对羟基苯甲醛生产新技术,产品成本低于目前现有的工艺。该工艺技术已实现工业化。 相似文献
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介绍了化工企业办公自动化系统功能需求分析,包括电子邮件功能、大量文档型的数据处理、应用自动化的工作流、支持协同工作和移动办公、完整的安全性控制功能以及与其他业务应用系统和Intemet集成。办公自动化系统对系统平台的需求分析,以及Lotus Notes/Domino在实现具有上述功能的办公系统的优势所在。 相似文献
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