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综述了我国挤塑聚苯乙烯泡沫塑料(XPS)行业含氢氯氟烃(HCFCs)替代技术的现状和发展趋势;从原料、设备、发泡剂等几个方面阐述了XPS泡沫行业进行发泡剂HCFCs替换的技术难点,并重点分析了替代产品的性能和市场状况。最后,介绍了几种较为成熟的HCFCs替代技术。 相似文献
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低温气相氟化催化剂的制备及应用研究 总被引:3,自引:1,他引:2
氟化催化剂是气相催化合成CFCs替代品HCFCs和HFCs的核心技术。综述了低温型氟化催化剂的制备及其在合成HCFCs和HFCs的应用方面的研究进展。建议开发在低温下具有较高活性的高价金属低温气相氟化催化剂。 相似文献
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于剑昆 《化学推进剂与高分子材料》2007,5(1):32-32
BOC公司称.它已开始在英国从事一项致力于提高人们对于替代包括氢氟氯烃(HCFCs)在内的破坏臭氧层的冷冻剂的认识活动。它将敦促欧盟在未来3年内停止使用HCFCs披其他破坏臭氧层的冷冻剂。 相似文献
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申桂英 《精细与专用化学品》2008,16(2):32-32
2007年12月7~8日,由中国制冷空调工业协会主办的“ODS淘汰暨HCFCs替代技术发展国际论坛”在北京新世纪日航酒店如期召开,来自国家环境保护总局对外经济合作办公室、世界银行中国ODS项目等相关组织和来自机械、制冷、建筑、化工等领域的国内外相关行业协会200多名代表就HCFCs替代品选择及替代技术问题进行了深入的讨论。 相似文献
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综述了几种我国挤塑聚苯乙烯泡沫塑料(XPS)行业含氢氯氟烃(HCFCs)的替代新技术,包括CO2技术、碳氢技术及氢氟烃技术。从发泡剂特性、发泡剂注入计量设备及挤出发泡设备等方面阐述了XPS泡沫行业进行发泡剂HCFCs替换的技术特点及难点。最后,指出CO2发泡技术将是XPS行业未来的发展趋势。 相似文献
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当前发达国家积极推动低GWP值ODS物质的替代,发展中国家正面临HCFCs的削减淘汰,因此全球各主要国家和地区均在积极开展低GWP值替代品和替代技术的研究和开发。从氟化工行业的角度出发,对各主要含氟物质的现有用途及替代趋势进行了简要的分析。 相似文献
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为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。 相似文献
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Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders,
but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled
VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-2H3]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s
syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting
that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the
ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the
corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured.
A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis
and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994. 相似文献
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高效液相色谱法分析化妆品中微量成分的研究进展 总被引:1,自引:0,他引:1
综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。 相似文献
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H. Toda Y. Mochizuki T. Kawanishi H. Kawashima 《Nutrient Cycling in Agroecosystems》2002,63(2-3):167-173
In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO2 L–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site. 相似文献
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我国硝酸工业生产技术新进展 总被引:1,自引:0,他引:1
系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐. 相似文献