新一代高强韧性WDL系列钢综合性能及应用

本文着重介绍武汉钢铁公司近年来研制开发的第二代高强度低合金钢—高强韧性WDL系列钢的综合性能及应用情况。该钢具有优异的焊接性能和低温韧性,板厚≤50mm钢板焊前不预热或稍加预热而不产生焊接裂纹,是制造大型压力容器（特别是低温和常温球罐）、水电站压力钢管和水轮机蜗壳、高寒地区使用的大型工程机械、大跨度桥梁及海上采油平台等装备的理想用材。     

节流式差压流量计的发展和现状

文章介绍节流式差压流量计的特点及标准化进程，煤气流量测量中存在的难点以及正在试图解决的途径。     

乌江渡水电站扩建工程开挖爆破对原水电站建筑物震动影响的控制研究

为确保原有的乌江渡水电站水工建筑物和发电设备以及扩建工程建筑物的施工安全,加快扩建工程施工进度,本扩建工程施工中对关键部位开挖所产生的爆破震动影响实施全面而有效的实时爆破监控,并根据监控成果的研究指导开挖爆破作业,以确定符合实际的安全爆破震动参数。     

Prediction of fire classification for wood based products. A multivariate statistical approach based on the cone calorimeter

Wood has long traditions as a building material, and is often used in construction elements, and as interior and exterior surfaces in the Nordic countries. In most applications, there are reaction to fire requirements to products used as surfaces, e.g. in escape routes and larger public spaces. Most wood products will therefore have to be treated with fire retardant (FR) agents to fulfil the strict requirements to properties connected to heat release and flame spread. Unfortunately, FR agents usually also increase the smoke production, as they cause a more incomplete combustion of the wood. The wood product manufacturers seek to find the optimal amount of FR additives where both heat release and smoke production in the classifying test are within the requirements given in the building regulations. This paper describes models for prediction of the European reaction to fire classes of wood products. The models are based on multivariate statistical analysis, and use test results from the cone calorimeter test as input. The presented models are, with very good precision, able to predict which Euroclass and additional smoke class a wood based product would obtain if it were to be tested in the single burning item test. Copyright © 2006 John Wiley & Sons, Ltd.     

Upgrading coal-derived liquids to diesel fuel

Distilled fractions of a coal-derived liquid from the H-Coal process were upgraded to diesel fuel by catalytic hydrotreatment. The total hydrotreated products were distilled into naphtha (<180°C) and diesel fuel fractions (>180°C) and the diesel fractions were analysed for hydrocarbon-type composition, hydrogen content and some diesel fuel properties. GC—MS-analyses were carried out on the hydrocarbon-type fractions to identify individual chemical compounds. To investigate the effect of different distillation cut points on diesel fuel yield and properties, cut points for one hydrotreated product were varied. The diesel fuel cetane numbers were correlated with percentage hydrogen, total aromatics and saturates. Cetane numbers above 40 were obtained for diesel fuels containing (i) more than 75% saturates, (ii) less than 15% total aromatics and (iii) a hydrogen content above 12.8%. Compounds identified by GC—MS-analyses (in the diesel fractions) were typical aromatic and cycloparaffin compounds. Normal-and iso-paraffin compounds were not detected. By varying the distillation cut point from 135 to 180°C, the cetane number of the residual diesel fraction improved from 37 to 44. This increase is ascribed to the removal of aromatic compounds in the 135–180°C boiling point range.     

TRANSFER FUNCTION MODEL ORDER AND PARAMETER ESTIMATION

Abstract. A distributed lag model with a rational transfer function is considered. We have demonstrated that the C -table can be used to determine the orders of the rational transfer function and the Padé table can be used to estimate the parameters of an identifiable transfer function. In case the model is not uniquely identified, the C -table reduces possible competing models to only a few for further examination. Padé approximant gives consistent initial values for possibly more efficient iterative procedures to estimate the coefficients of the identified model. Some asymptotic results on the estimation of the C -table and the Padé table are given. A few examples are presented to demonstrate the effectiveness of the method.     

Treatment of Humic Waters By Ozone

Two different generators for ozone were tested, a traditional electrical discharge generator and a generator based upon UV–irradiation of air at 150–180 nm. It was demonstrated that the traditional generator gave slightly higher reductions in levels of color for equivalent ozone dosages. Both gases affected the molecular weight distribution in the way that the bigger molecules were broken down to smaller ones. No significant difference between the molecular weight reduction efficiency of the gases was found.     

地热、温泉水利用中氡的防护

地热作为一种比较经济、方便的新能源的同时,也给公众和环境带来辐射影响。本文介绍了地热和温泉水中~(222)Rn 的放射性水平及其对人体健康的影响,对地热、温泉水利用中氡的防护措施提出了一些建议。     

GAO Feng~1,LI Wei~2,TANG Zon

tific Experiment Center of Guangxi Medical University,Nanning 530021,China)Objective:To investigate the mutation pattern of adenomatous polyposis coli(APC),Kirsten-ras(K-ras) and p53 genes in sporadic colorectal cancer tissues.Meth