Monoacylglycerols derived from butter oil by Penicillium roquefortii in suspension cultures

Structural isomers of monoacylglycerols (monoglycerides, MAGs) were identified and compared after degradation of butter oil by two strains of Penicillium roquefortii and a commercial lipase from P roquefortii (EC 3.1.1.3) at pH 7.0 and 10 °C. The conditions were selected as they were comparable with those used in the manufacture of blue mould‐ripened cheese. The commercial lipase was selected to compare with the fungal strains in terms of acyl migration. Results showed that the main isomers formed by lipolysis with the commercial lipase were sn‐2 MAGs (64 mol%), whilst spores and emerging mycelia of P roquefortii produced mainly sn‐1(3) MAGs (83–90 mol%). The work reported here may lead to further assessment of different MAG structural isomers as natural preservatives in foods and dairy products. © 2002 Society of Chemical Industry     

天铁炼钢厂四流中间包流场的水模实验及优化

介绍了天铁炼钢厂中间包水模实验原理和过程，分析了斜、直、圆三种型式挡渣墙模拟结果，提出了合理的挡渣控流方案，在生产实践中使用效果良好。     

CHA无机凝胶体系的研究及应用

过去低渗油藏调剖，注入性和堵塞性很难统一，新研制的CHA无机凝胶体系是一种易注入、堵塞能力强的调剖剂，而且成胶时间在一定范围内可控。研究了配比、温度对CHA无机凝胶体系成胶时间的影响，成胶前的注入性，成胶后在高温高盐条件下的堵塞能力，得到了可应用于现场的CHA无机凝胶体系。该调剖剂在濮城油田沙三段和文卫结合部等高温、高盐低渗油藏应用后，取得了很好的效果。     

铸造Ti—0.2Pd合金SF—1000双级风机叶轮的研制

Ｔｉ－０．２Ｐｄ合金ＳＦ－１０００双级风机叶轮是大型盐酸再生设备的主要部件，采用整体铸造方法制造，无论在技术上还是经济上都是十分有利的。本文主要介绍采用加工石墨，铸铁组合型，真空电弧凝壳熔炼铸造工艺，成功地研制出整体铸造风机叶轮。     

天铁炼钢厂板坯漏钢原因分析及预防

针对天铁板坯连铸机一年多来发生的漏钢事故，分析了产生的原因，提出了预防改进的措施，对今后的生产有很好的指导意义。     

栅板注射模设计

分析了栅板零件的工艺性 ,介绍了栅板注射模的设计方案及设计要点 ,并对浇注系统的设计计算作了较详细的阐述。该模具经生产验证 ,各部件动作灵活、可靠 ,生产的塑件质量符合要求。     

Concast连铸机自控系统简介

天津钢铁有限公司引进了瑞士Concast公司6机6流方、圆坯连铸机及相关技术，文章简要介绍了Concast连铸机的自动控制系统的特点和功能。     

Experimental and analytical study on the spray characteristics of dimethyl ether (DME) and diesel fuels within a common-rail injection system in a diesel engine

This paper investigates the effect of injection parameters on the characteristics of dimethyl ether (DME) as an alternative fuel in a diesel engine with experimental and analytical models based on empirical equations. In order to study macroscopic and microscopic characteristics of DME fuel, this work focuses on the atomization characteristics of DME and compares experimental and predicted results for spray development obtained by empirical models for diesel and DME fuel. Detailed comparisons of spray tip penetration from three different empirical correlations and from visualization experiments of diesel and DME fuels were conducted under various fuel injection conditions. In comparison with the results of different empirical equations for measured spray tip penetration, the experimental results of this study provide good agreement with the calculation results based on empirical equations, except during the earliest stage of the injected spray sequence. The results of atomization characteristics indicate that DME showed better spray characteristics than conventional diesel fuel. Also, the fuel injection delay and maximum injection rate of DME fuel are shorter and lower than those of diesel fuel at the same injection conditions, respectively.     

结晶器电磁制动技术在梅山高效连铸中的应用

为了得到较好的铸坯表面质量 ,满足生产高附加值 ,高技术含量的钢种要求 ,梅山炼钢厂在 2号高效连铸机上引进了国际上比较先进的结晶器电磁制动技术。主要介绍了结晶器电磁制动技术的基本参数和在梅山的实际应用。     

定向凝固空心叶片制壳工艺的改进

分析了在先进发动机定向凝固空心叶片熔模精密铸造生产中出现两种缺陷的性质和产生原因，从壳型制造工艺方面提出了改进措施，提高了叶片合格率。