烧碱离子膜NX2030膜运行情况总结

介绍了杜邦NX2030离子膜运行情况,分析了影响膜长周期运行的因素。结合膜运行六年多的概况,总结了生产运行中管理和操作要点,为进一步维护运行好离子膜提供了参考。     

全卤制碱淡盐水MVR回收利用技术应用

结合某公司全卤制碱淡盐水MVR回收利用技术示范工程,研究了该工艺的运行参数、设备运行情况、系统运行控制情况,以及运行效益情况等,分析了运行中存在的问题及运行中重要的影响因素。     

仪化涤纶一厂四台热媒炉最佳运行方式的探讨

对不同运行方式下 ,热媒炉的运行负荷进行了计算 ,从装置的平均热效率、燃油消耗及装置运行的稳定性等方面对不同的运行方式进行了综合比较 ,提供了一套最佳运行方式。     

汽轮机滑压运行方式的应用

汽轮机组在变负荷运行时可采用定压运行和滑压运行两种运行方式。本文定性地分析并比较了2种运行方式对机组热经济性及安全性的影响,提出了定压运行和滑压运行两种运行的优越性和经济性。     

离子膜N2030运行情况

介绍了杜邦N2030离子膜运行情况,并对影响膜长周期运行的一系列因素做了分析。结合该膜运行6年多时间的情况,总结了生产运行中的管理和操作要点,以进一步维护运行好离子膜。     

干燥机托轮位置的分析及调整

针对化纤厂干燥机系统运行中出现的转动筒体的位置调整,通过对干燥机托轮和轮带的受力分析以及托轮位置的具体调整方法,从根本上解决了影响干燥机运行中的问题,收到了良好的效果,达到了设备运行要求,提高了设备运行周期,保证了装置平稳运行。     

环氧乙烷精制单元生产优化

介绍了吉林石化乙二醇厂乙二醇装置增设环氧乙烷精制单元项目后的优化运行情况,包括项目运行中的工艺运行优化、对运行存在问题的管线改造和停车清洗置换方案优化情况.通过对该单元的持续运行优化,极大提高了单元运行的综合效益.     

丁二烯装置长周期运行

介绍了抚顺石化公司16万t/a丁二烯装置的运行情况,该装置自开工至今已经连续运行近2 a;在该装置长周期运行的基础上,分析了制约丁二烯装置长周期运行的因素和产生原因,并提出了防范措施,为今后装置的安稳长满优运行,提供借鉴依据。     

反渗透系统运行故障及实例分析

反渗透系统在水处理领域的应用越来越普及,反渗透系统的运行故障也困扰了发电企业的经营者和运营者,该文对反渗透系统运行的各种影响因素进行了详细的介绍,并对运行中常见的故障进行了实例分析。为确保系统长期稳定运行,从原水预处理系统的设计和运行、反渗透系统的运行维护和管理等方面提出了相关建议。     

锅炉运行及设备维护问题重点探讨

锅炉运行的安全性和稳定性基本决定了锅炉供应可靠性能,因此,为进一步提升锅炉运行过程中安全性,必须全面加强对锅炉运行的维护管理工作,避免锅炉工作过程中出现故障.基于锅炉运行的基本原则和运行方式、运行注意事项分析了影响锅炉正常工作的故障因素,提出了锅炉日常维护优化措施,以供参考.     

佛山市顺德新城区降水中污染物的监测和分析

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。     

Metabolism of trideuterated iso-lignoceric acid in rats in Vivo and in human fibroblasts in culture

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.     

Denitrification in shallow groundwater in a coastal agricultural area in Japan

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.     

我国硝酸工业生产技术新进展

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.     

高效液相色谱法分析化妆品中微量成分的研究进展

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。