SH/T3083-1997《石油化工钢储罐地基处理技术规范》的编制背景和内容简介

中国石油化工总公司批准发布的《石油化工钢储罐地基处理技术规范》自1998年3月1日起施行，本文作者作为主要编制工作负责人，在对该规范内容予以简要介绍的同时，对该规范的编制过程和特点进行了深入说明，以利其在石代储罐建设工程中发挥应有的效益。     

Combined Effects of Different Overload Ratios and Nitriding Process on Fatigue Crack Growth of AISI 4140 Steel

The combined effects of different overload ratios(OLRs)and nitriding process on fatigue crack growth(FCG)were analyzed.Steel compact tension specimens made of AISI 4140 steel were subjected to the plasma nitrification process using agas mixture of 50% N2 and 50% H2 at 500℃for 2h.Structural properties of the samples were studied by scanning electron microscopy,optical microscopy,microhardness testing and digital imaging.Plasma nitriding slowed down FCG,but the crack growth retardation caused by the overload was reduced when the OLR was 2.0and 2.5.Nitriding did not take effect when the OLR was 1.5and 3.0.     

广东省揭东县合升石材机械有限公司让利酬宾

本公司在投产一系列机械设备四周年之际，开展让利酬宾活动，具体内容如下： 　　一、价格特优     

A novel indicator system for catalytic spectrophotometric determination and speciation of inorganic selenium species （Se（Ⅳ）, Se（Ⅵ）） at trace levels in natural lake and river water samples

A novel catalytic kinetic method is proposed for the determination of Se(IV), Se(VI), and total inorganic selenium in water based on the catalytic effect of Se(IV) on the reduction of Celestine blue by sodium sulfide at pH 7.0 phosphate buffer. The fixed-time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the two calibration graphs are linear with a good correlation coefficient in the range 2–20 and 20–200 μg·L⁻¹ of Se(IV) for the fixed-time method at 30°C. The experimental and theoretical detection limits of the developed kinetic method were found to be 0.21 and 2.50 μg·L⁻¹ for the fixed-time method (3 min). All of the variables that affect the sensitivity at 645 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se(IV) determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus as long as chelating agents of thiourea and thiosulphate. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The relative standard deviations (RSDs) for ten replicate measurements of 2, 10, and 20 μg·L⁻¹ of Se(IV) change between 0.35% and 5.58%, while the RSDs for ten replicate measurements of 3, 6, and 12 μg·L⁻¹ of Se(VI) change between 0.49% and 1.61%. Analyses of a certified standard reference material (NIST SRM 1643e) for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. The Se(IV), Se(VI), and total inorganic selenium in lake and river water samples have been successfully determined by this method after selective reduction of Se(VI) to Se(IV).     

奥氏体铸铁在制碱工况介质中的应用试验研究

1 前言 纯碱、氯化铵和苛化法烧碱的工业化生产装置,是由多种化工单元设备组成的长流程、连续运转系统。任何一个设备零件的腐蚀损坏,都可能致使整个系统停工或减产。 制碱系统中不但有大量的盐水、氨盐水、重碱分离母液、氟化铵分离母液、氯化钙废液以及NaOH等强腐蚀性介质,而且介质中还悬浮着NaCl、NaHCO_3、NH_3Cl、CaCO_3等固体颗粒,故许多设备除受强烈的电化学腐蚀,还伴随着悬浮颗粒的磨损作用,致使设备早期损坏。因而有针对性地选择设备材质是一个重要的课题。     

石油化工钢储罐基础工程事故分析与处理

本文主要介绍国内外一些油罐基础工程典型事故，从过去的工程破坏实例中进行分析研究，找出可能导致破坏的原因，提出防止油罐基础破坏的措施或方法。     

塑料排水板与碎石桩综合处理大型油罐软基新技术在沪通过部级鉴定

由上海高桥石油化工设计院、中国石化勘察设计院等单位进行的“塑料排水板与碎石桩综合处理5万m3油罐软基设计与试验研究”，在上海高桥石化公司炼油厂海滨油库两座5万m3油罐工程中获得成功。中国石化总公司组织的技术鉴定会于1998年3月对日在上海召开，出席会议的有中国建筑科     

加工平行阀手轮的四工位回转工作台式组合机床

本文介绍了该机床加工工艺,结构特点,工作台,夹具及攻丝头的结构及调试中的问题。图6幅。