Phase transformation behavior in Al-Zn-Cu alloys by hammering

The 5Cu40Zn55Al and 15Cu20Zn65Al alloys were prepared in the AI-Zn-Cu system, There exist the metastable phases ε and θ in the two alloys after homogenization treatment and furnace cooling, respectively. It is shown that the particles are refined from 3 mm to less than 10 μm after hammering the two alloys but there are still metastable phases. This means that the phase constituents of the two alloys have no changes by the deformation, which is different from that by balling. The phase constituents are not changed at room temperature by hammering, which is dependent on the deformation mechanism of hammering.     

New method for determination of the pose of the grinding wheel for thinning drill points

Traditionally, twist drills are reconditioned by thinning the web so the correct chisel edge length is restored. Recently, thinning has been included in the original design of drills so as to reduce torque and tool force. Because the International Standards Organization (ISO) has a system which can comprehensively model conventional twist drills but cannot model thinning specifications, this paper presents a system for precise mathematical modeling and CNC control of a 6-axis grinding workstation for drill thinning. The presented method determines the position and orientation of the grinding wheel based on the evaluated rake and clearance angles of ISO standards for 2-flute twist drills. The mathematical model and background are discussed. For verification and demonstration, two experimental drills are produced to the identical ISO standard except that one is thinned. The modeling herein is of value to industry and research if incorporated into computer software for drill design and manufacture. It is suitable for linear notch-type cutting with controlled variable rake angle along the secondary cutting edge for purposes of thinning, notching, dubbing and advanced drill research.     

高线精轧机平衡缸漏油分析及改进

分析了广州钢铁企业集团公司高线厂精轧机平衡油缸漏油的危害和原因，指出了这种油缸在设计上存在的缺陷，并提出了改进措施，改进后漏油问题得到了解决。     

机械镀锌过程中先导金属的研究

通过多次试验观察，借助于扫描电子显微镜，结合物理化学、电化学的基础理论知识，对机械镀锌过程中先导金属进行了研究。分析了先导金属在镀层中的分布以及先导金属对机械镀锌形层过程的影响。结果表明机械镀锌过程中的确有先导金属存在，在机械镀锌过程的不同阶段，有着不同的金属起着先导金属的作用。先导金属可以促进机械镀锌镀层的结合强度。     

基于Word文档的数据隐藏方法

在分析当前数据隐藏与恢复相关技术研究基础上,参照微软官方最新公布的复合文档存储规范,从利用载体Word文档现有空间中未真正使用部分和适度扩展新空间两条思路出发,设计一种利用Word文档作载体隐藏秘密信息的解决方案,包括在文字、各种嵌入式对象及其相应控制结构数据中隐藏信息。实践表明,隐藏数据后的载体文档可以被正常拷贝和使用电子邮件传送,根据需要隐藏的信息随机选择使用该方案,被隐藏信息更不容易被侦测出来,被二次编辑后被隐藏信息一般不会被破坏,鲁棒性不错,具有一定的实用价值。     

系统的几种表示方法的探讨与分析

针对“信号与系统分析”、“数字信号处理”课程中对系统的描述与分析过于零散,导致学生学习时不好理解这一现象,分析并归纳了描述系统的数学模型、框图、冲激响应、系统函数及系统频率响应五种方法的基本原理及相应的表达式,并给出了系统的几种表示方法之间的转化关系,对于促进学生在学习过程中对于系统的理解和掌握十分有益.     

基于提高频繁项集挖掘效率算法在市场分析中的探讨

频繁模式是频繁地出现在数据集中的模式(如项集、子序列或子结构)。如频繁地同时出现在交易数据集中的商品的集合是频繁项集,利用高效率的频繁项集挖掘算法来发现频繁项集,通过分析这些频繁项集来预测商品的销售情况。     

模糊解耦控制在集散控制中的应用

该文结合循环流化床锅炉的特点,采用了霍尼韦尔公司的EPKS控制系统对锅炉进行控制,设计了硬件的配置,主要设计了控制策略,将模糊解耦控制应用在控制策略中,进行了实验仿真,实验结果表明模糊解耦控制具有良好的解耦效果。