SA-213T11钢管扩口开裂缺陷分析

采用扫描电镜和能谱仪等检测手段分析SA-213T11钢管扩口开裂缺陷,从产品的理化性能和生产工艺过程两个方面考察扩口缺陷形成的原因。结果表明,钢管扩口开裂与钢中存在大型夹渣有关,而大型夹渣与连铸过程中中间包的挡渣墙倒塌有关。采用更换高质量挡渣墙等措施解决了中间包挡渣墙倒塌的问题,消除了钢管扩口开裂缺陷。     

矩阵C-特征值的Gersgorin包含区间的推广

在矩阵C-特征值完全集定义基础上,推广了矩阵C-特征值的Gersgorin包含区间,得到推广的Gersgorin定理和Ostrowski定理.     

低碳钢头坯洁净度研究

采用氧氮分析、金相分析、大样电解分析、扫描电镜及能谱分析等,研究LD—Ar站—CC生产的低碳钢头坯不同浇铸长度处的洁净度变化规律,并与正常坯洁净度水平进行对比分析。结果表明,头坯中T[O]和氮含量均随着浇铸长度的增加呈明显的下降趋势;头坯中显微夹杂物数量和大型夹杂物数量随着浇铸长度的增加大体都呈减少趋势;头坯中显微夹杂物主要来源于脱氧产物和二次氧化,大型夹杂物来源于二次氧化、结晶器卷渣、中间包卷渣和钢包引流砂;与正常坯洁净度相比较,头坯洁净度在浇铸长度大于3m以后与正常坯水平相一致。     

基于向量线段的特殊字符识别

传统的OCR技术在某些特定方面,如印刷体数学公式中特殊字符的识别存在困难和限制,其识别结果的准确率不尽如人意.为此,重点介绍基于向量线段的特殊字符识别算法规则和识别系统的设计.提出通过提取字符中的向量线段进行特征比较的分析方法,并将噪点去除算法融入其中.实验表明,该方法对于特殊字符的分析识别具有较好的准确性和应用前景.     

语义网不精确本体构建方法研究

不精确性包括模糊性和粗糙性,同理不精确本体也包含了模糊本体和粗糙本体.通过对粗糙本体构建方法与模糊本体构建方法的综述,讨论了在不精确本体研究中的关键问题,在此基础上对各种粗糙本体构建方法与模糊本体构建方法进行分析比较.为了解决当前不精确本体构建中的瓶颈问题,提出一种基于包含度理论的不精确本体构建方法,在该方法中将粗糙集与模糊集理论引入传统本体模型,使用包含度理论进行关系描述,讨论了未来的研究方向.     

DCS在焦炉地面除尘系统中的应用

以和利时DCS系统在某100万t捣固焦炉地面除尘站系统中的应用为例,介绍了袋式除尘系统的工艺流程、工艺联锁与控制要求,并依此制订了基于和利时MACSV系统的详细实现方案。系统具有免维护、除尘效果良好等特点。系统投运后,不仅减少了工人劳动强度,改善了工厂周边环境,并且取得了良好的经济效益和社会效益。     

从原油中脱除石油酸技术现状与研究进展

介绍了近几年来国内外发展起来的石油脱酸技术方法,其中重点介绍了碱洗脱酸技术、氨醇脱酸技术、加氢脱酸技术、热分解脱酸技术、溶剂抽提脱酸技术等除去油中环烷酸技术,分析对比了各种脱酸技术的优劣,并阐述了脱酸分离技术在国内外的研究现状及发展趋势。     

SEM in-situ investigation on fatigue cracking behavior of P/M Rene95 alloy with surface inclusions

The low-cycle fatigue behavior of powder metallurgy Rene95 alloy containing surface inclusions was investigated by in-situ observation with scanning electron microscopy （SEM）. The process of fatigue crack initiation and early stage of propagation behavior indicates that fatigue crack mainly occurs at the interface between the inclusion and the matrix. The effect of inclusion on the fatigue crack initiation and the early stage of crack growth was very obvious. The fatigue crack growth path in the matrix is similar to the shape of inclusion made on the basis of fatigue fracture image analysis. The empiric relation between the surface and inside crack growth length, near a surface inclusion, can be expressed. Therefore, the fatigue crack growth rate or life of P/M Rene95 alloy including the inclusions can be evaluated on the basis of the measurable surface crack length parameter. In addition, the effect of two inclusions on the fatigue crack initiation behavior was investigated by the in-situ observation with SEM.     

Numerical simulation on inclusion transport in continuous casting mold

Turbulent flow, the transpor＇t of inclusions and bubbles, and inclusion removal by fluid flow, transport and by bubble flotation in the strand of the continuous slab caster are investigated using computational models, and validated through comparison with plant measurements of inclusions. Steady 3-D flow of steel in the liquid pool in the mold and upper strand is simulated with a finitedifference computational model using the standard k-εturbulence rondel. Trajectories of inclusions and bubhles tire calculated by integrating each local velocity, considering its drag and buoyancy forces, A ＂random walk＂ model is used to incorporate the effect of turbulent fluctuations on the particle motion. The attachment probability of inclusions on a bubble surface is investigated based on fundamental fluid flow simulations, incorporating the turbulent inclusion trajectory and sliding time of each individual inclusion along the bubble surface as a function of particle and bubble size. The chunge in inclusion distribution due to removal by bubble transport in the mold is calculated based on the computed attachment probability of inclusions on each bubble and the computed path length of the bubbles. The results indicate that 6%-10% inclusions are removed by fluid flow transport. 10% by bubble flotation, and 4% by entrapment to the submerged entry nozzle （SEN） walls. Smaller bubbles and larger inclusions have larger attachment probabilities. Smaller bubbles are more efficient for inclusion removal by bubble flotation, so Inng as they are not entrapped in the solidifying shell A larger gas flow rate favors inclusion removal by bubble flotation. The optimum bubble size should be 2-4mm.     

Banach空间中的一类广义混合非线性隐拟变分包含

给出了Banach空间中一类广义集值混合非线性隐拟变分包含问题，通过对m-增生映象运用Nadler定理和隐预解算子技巧，构建了这类广义变分包含的迭代算法，并证明了其解的存在性和由迭代算法生成的迭代序列的收敛性。