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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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简述了我国塑料涂料的现状及发展以及国内外塑料涂料近期的技术进步,就我国塑料用玩具涂料出口所面临的严重挑战,提出了一些建议来应对这些问题。 相似文献
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《Journal of the European Ceramic Society》2023,43(10):4541-4548
A systematic study of the solid-state synthesis, pressureless sintering, and grain growth kinetics of Hf6Ta2O17 is presented. The ideal conditions for solids-state synthesis of Hf6Ta2O17 powder with minimal particle necking was 1250 °C for 2 h in air. The resultant powder has an average particle size of 210 ± 70 nm. The combined synthesis and ball-milling procedure produces highly sinterable Hf6Ta2O17 powder, achieving > 97 % of theoretical density after pressureless sintering at 1600 °C for 2 h in air. The grain growth mechanism was sensitive to processing conditions, appearing to be primarily driven by surface diffusion below 1600 °C and grain boundary diffusion above 1650 °C. The respective activation energies for grain growth were found to be QS = 659 ± 79 kJ mol−1 and QGB = 478 ± 63 kJ mol−1. 相似文献
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Y. Bautista J. Gonzalez J. Gilabert M.J. Ibaez V. Sanz 《Progress in Organic Coatings》2011,70(4):178-185
The nanoscratch test, used in this study, quantitatively characterizes the scratch behaviour of coatings. Some of the obtained parameters are plastic and elastic deformation, critical load to start the scratch, chipping or other change in the scratch mechanism of the coating. The knowledge of the scratch mechanism allows the optimisation of the material behaviour. In the present study the scratch resistance with the wear resistance has been correlated for nanocomposite coatings. Knowledge of mechanical properties extracted from the scratch test, supports the optimization of the coating against wear. The study was applied to nanocomposite coatings with different polymer matrices, different percentages and nature of nanoparticles. 相似文献
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In order to manufacture the microporous, breathable films applicable to absorbent articles, LDPE, LLDPE, and HDPE/zeolite composite films filled with zeolite, uncoated and coated with stearic acid, were prepared. The stearic acid is verified as a coupling agent by how much effect it has on the various properties such as mechanical, thermal, morphological, and rheological measurements. The incorporation of stearic acid on the zeolite surface improved the flexibility of polymer matrices. In particular in the LLDPE and HDPE composites, the increase in the area of the air holes and decrease in the number of the air holes by merging among neighboring air holes was prominent upon higher filler loading, therefore resulted in enhanced modulus, elongation and impact properties. 相似文献
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装饰性镀层由于其鲜艳的外观而日益受到人们的青睐。为提高装饰性镀层的耐蚀性,延长其使用寿命,开发出一种无色透明涂膜。该涂膜由新型改性聚合物树脂和多种助剂组成,具有良好的耐磨、抗蚀及抗紫外线照射性能,工艺简单,可广泛用于镀层的表面防护与装饰。 相似文献
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D. W. Rutland 《Nutrient Cycling in Agroecosystems》1991,30(1):99-114
Most fertilizers have some tendency to form lumps or agglomerates (caking) during storage. The mechanism of caking in fertilizers is most often attributed to the formation of salt bridges and/or capillary adhesion. The severity of caking can be influenced by a number of factors, such as chemical composition, moisture content, particle structure, mechanical strength, hygroscopic properties, product temperature, ambient conditions, storage time, and storage pressure. The various methods of reducing or eliminating caking in fertilizers basically involve process control, storage/packaging conditions, and/or addition of anticaking agents.Caking mechanisms, factors that influence caking, and methods of prevention are discussed in this paper. Particular attention is given to the various types of anticaking agents and their modes of action. The paper also provides a fairly comprehensive list of commercially available anticaking agents and their producers. 相似文献
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综述了目前中国涂料业的发展概况,并介绍了今后发展趋势和研究热点──防腐蚀涂料、卷材涂料、功能涂料、绿色木器涂料和粉末涂料等5种涂料。 相似文献
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"三带"环保型防腐涂料的研制 总被引:2,自引:0,他引:2
研制出一种带锈、带水、带油环保型防腐涂料,介绍了其配方及制备工艺,探讨了其作用机理,研究了添加剂和渗透促进剂对涂膜性能的影响,该涂料制备简单、成本低、性能优良、环境污染小。 相似文献