Trace elements in particles of motor vehicle exhaust in Shanghai

A nuclear microprobe with high spatial resolution and high analytical sensitivity was applied to analyze trace elements,especially lead,in vehicle exhaust of Shanghai city.The result shows that the chemical composition and its corresponding x-ray relative intensity are different among different vehicle exhausts.There are many kinds of metal elements in particles of vehicle exhaust.most are harmful to people,such as Ti,Cr,Mn,Pb,etc.We found that the lead concentration was 6820μg/g and the bromine concentration was 5300μg/g in the exhaust from Santana using leaded gasoline(SULG).which is higher than any other kinds of vehicle exhausts.We have also detected the minimum lead in the particles of unleaded gasoline and its content varies from one to another.Its mean concentration was 450μg/g and the highest reached 6210μg/g.The unleaded gasoline‘s Pb existed in the whole particle while the leaded gasoline‘s enriched in the surface of the particle and was more harmful to the human beings.     

JOINING MECHANISMS OF β''''-Al2O3 CERAMIC AND PYREX GLASS TO Al MATRIX COMPOSITE

The bonding of β'-Al2O3 and pyrex glass to Al matrix composites by anodic bonding process is achieved. The microstructure of the bonded interface and the joining mechanisms are analyzed with scanning electron microscope (SEM), energy dispersive X-ray fluorescence spectrometer (EDX). It is observed that the bonding region across the interface consists of the metal layer, oxide transitional layer and the ceramic layer, with the transitional layer composed of surface region and sub-surface region. The bonding process can mainly be categorized into anodic bonding process and solid state diffusing process. The pile-up of the ions and its drift in the interface area are the main reasons for anode oxidation and joining of the interface. The temperature, voltage and the drift ions in the ceramic or glass during the bonding process are the essential conditions to solid state diffusing and oxide bonding at the interface. The voltages, temperature, pressure as well as the surface state are the main factors that influence the anodic bonding.     

PURIFICATION AND PROPERTIES OF TRANSGLUTAMINASE FROM STREPTOVERTICILLIUM MOBARAENSE

Transglutaminase (TGase) was separated from the culture broth of an isolated strain of Streptoverticillium mobaraense. The crude enzyme was prepared by centrifugation, ultrafiltration, precipitation by alcohol, centrifugation and freeze‐drying. The yield after these processes was 65–70%. Then the enzyme was purified to homogeneity by chromatography on CM‐cellulose and Sephadex G‐75 on which the yields were about 70% and 80%, respectively; the purified folds reached 2.5–4.7 and 1.08–2.06, respectively. The molecular weight of this TGase was 39,500–40,100 Da by gel filtration chromatography. Optimum enzyme activity was observed in the pH range of 5.0–7.0, and it was maintained stable at 20–40C. The optimal temperature and pH was 52C and 6.0, respectively. At 1 mM and 5 mM metal ion or inhibitors concentration, TGase activity was strongly inhibited by Zn²⁺ and NEM, and not affected obviously by Ba²⁺, Ca²⁺, Co²⁺, Cu²⁺, Fe²⁺, Fe³⁺, Mg²⁺, Mn²⁺, Na⁺ as well as PMSF and EDTA. The effects of these additions on this TGase were compared with those of other microbial TGases.     

公司大门工程建设施工

大门小品建筑属多项目综合性工程。本文作者从管理者的角度 ,通过对公司大门及附属工程施工质量控制的总结 ,说明了质量控制应贯穿于工程施工的全过程     

储层石蜡沉积预测技术研究与应用

在油田开发过程中 ,由于油藏温度、压力等条件的变化 ,高含蜡原油在近井带容易产生石蜡沉积 ,堵塞地层孔隙或裂缝 ,严重影响油田开采 ,尤其对于低渗油田 ,伤害特别严重。文中应用理想溶液理论、质量守恒和能量守恒等基本原理 ,建立更符合油田实际情况的油藏中石蜡沉积预测数学模型 ,开发一套方便实用的油藏中石蜡沉积预测软件系统FPOS1 0。在此基础上 ,应用室内实验数据和现场数据对吉林新民油田油井石蜡沉积情况进行预测和现场拟合 ,确定新民油田临界石蜡沉积半径为 2 5m ,快速、准确地为现场清防蜡措施提供理论依据。     

石油系油浆与煤系闪蒸油的焦化性能——I．热解条件的影响

通过偏光显微镜观察了石油系油浆（LH）与煤系闪蒸油（SN）焦化后所得焦块的光学结构。结果表明，在较宽条件下两种原料单独焦化均得不到取向度高的流线型结构。将两种原料以一定比例混合后先热解丙焦化所得焦块的光学结构明显好于二者混合后直接焦化所得焦块的光学结构，其中LH和SN以3：2的重量比混合后在440℃、1MPa下热解3．5h然后再在530℃、1MPa下焦化8h所得焦块为具有较高取向度的流线型结构，适合于作为针状焦的起始原料。     

当心新的"信息化陷阱"——合理规划、慎重选择"信息化"切入点

信息化巳成为当今的一大热点，文章以客观的角度分析了企业信息化应用的现状，阐述了如何合理规划、选择“信息化”切入点，对待实施信息化的企业具有重要的意义。     

土钉加锚杆联合支护基坑的失稳分析及处理

根据具体工程实例,介绍了在基坑开挖时采用土钉加锚杆的联合支护方式后在施工过程中出现坍塌裂缝的现象,针对这一现象,分析了施工条件与环境,得出了事故发生的原因,并结合实际情况提出了处理措施.