大直径平焊法兰的焊接变形与控制

在压力容器的生产制造过程中,经常发生大直径平焊法兰的焊接变形问题,通过分析变形原因,提出控制变形的措施,从而为防止类似工件的焊接变形提出指导方法。     

Effects of titanium coating on property of diamond

The titanium film was coated on the surface of diamond crystal in order to improve the chemical properties of diamond and the effect of titanium coating on the property of diamond was discussed. The anti-impacting strength, the oxidization process and the soakage property between vitrified bond and diamond were investigated. It is found that, when the titanium film is coated on the surface of diamond crystal, the soakage angle between vitrified bond and diamond decreases from 39.5° to 34.5° at 993 K, and the oxidization degree on the surface of diamonds is lowered greatly.     

Directional solidification casting technology of heavy-duty gas turbine blade with liquid metal cooling (LMC) process

In this work, some important factors such as ceramic shell strength, heat preservation temperature, standing time and withdrawal rate, which influence the formability of directionally solidified large-size blades of heavy-duty gas turbine with the liquid metal cooling(LMC) process, were studied through the method of microstructure analysis combining. The results show that the ceramic shell with medium strength(the high temperature flexural strength is 8 MPa, the flexural strength after thermal shock resistance is 12 MPa and the residual flexural strength is 20 MPa) can prevent the rupture and runout of the blade. The appropriate temperature(1,520 ℃ for upper region and 1,500 ℃ for lower region) of the heating furnace can eliminate the wide-angle grain boundary, the deviation of grain and the run-out caused by the shell crack. The holding time after pouring(3-5 min) can promote the growth of competitive grains and avoid a great deviation of columnar grains along the crystal orientation 001, resulting in a straight and uniform grain structure. In addition, to avoid the formation of wrinkles and to ensure a smooth blade surface, the withdrawal rate should be no greater than the growth rate of grain. It is also found that the dendritic space of the blade decreases with the rise of solidification rate, and increases with the enlarging distance between the solidification position and the chill plate.     

黄芩甙纳米乳的制备

研制了黄芩甙纳米乳并对其进行了质量评价。通过绘制伪三元相图优选处方,以肉豆蔻酸异丙酯(IPM)、液体石蜡和维生素E油为油相,蓖麻油聚氧乙烯醚(EL-40)为表面活性剂,乙醇为助表面活性剂制备黄芩甙纳米乳,用透射电子显微镜(TEM)、Nicomp388/ZetaPALS激光粒度测定仪分别考察了其形态和粒径;通过恒温加速实验检验了其稳定性。黄芩甙纳米乳在透射电镜下呈圆球形,分布均匀,平均粒径为(35.3±0.27)nm,恒温加速实验结果显示其未分层,仍为澄清透明纳米乳状液。纳米乳质量稳定,能提高黄芩甙的溶解度,且有很好的皮肤渗透性,提高了化妆品在皮肤上的延展性,可望用作皮肤化妆品基质。     

悬臂式排桩支护结构位移和弯矩的分析研究

文章以武汉阅马场交通综合整治工程首义广场隧道工程为项目依托,以悬臂式排桩支护结构形式为主要研究目标,分别采用解析法和数值模拟法对武汉阅马场交通综合整治工程首义广场隧道工程中悬臂式排桩支护结构的位移和弯矩进行计算,并相互间进行结果的对比分析,研究分析了悬臂式支护结构在基坑开挖过程中桩身侧向位移和受力弯矩的分布规律和特点.     

人民币升值影响下国际工程汇率风险分析与规避

近年来人民币持续升值,给国际工程承包业带来了很高的汇率风险。在对人民币升值态势进行分析的基础上,归纳了国际工程汇率风险的种类,梳理了项目各阶段汇率风险产生的关键环节,有针对性地提出了合理确定汇率风险管理的层次目标、评估币种最大汇率风险承受能力、强化合同谈判降低汇率风险、与分包商和供应方尽量采用业主支付币种和金融方法等汇率风险控制措施。并以刚果（布）国家1号公路Ⅱ期工程为例分析了该项目的汇率风险及相应的规避措施。     

TiO2与聚合物复合薄膜的离子自组装制备及表征

在常温下,以钛酸丁酯[(C4H9O)4Ti]和聚四苯乙烯磺酸钠(PSS)作为前驱物在普通载玻片上用离子自组装法制备了TiO2纳米粒子/PSS复合薄膜,复合薄膜的透过率随镀膜次数或薄膜厚度的增加而呈现周期性变化。透射电镜(TEM)测试结果表明,TiO2呈板钛矿晶体结构,薄膜连续而均匀,TiO2的平均粒径是3.6nm。光电子能谱仪(XPS)测试结果显示,薄膜中含有Ti、O、C元素,载玻片表面完全被TiO2纳米复合薄膜所覆盖。     

数字化折页机控制系统开发

针对当前我国折页机数字化程度低的问题,对数字化折页机的控制系统进行了研究,开发了折页机硬件控制系统和上位机控制系统,实现了折页机的数字化控制.上位机系统的开发,简化了折页机操作方式.折页模式的自动预置大大降低了系统的工作准备时间,减少了因系统预置造成的浪费,提高了工作效率.JDF网络接口可视系统与印刷流程控制系统通讯,有利于实现折页机的远程监控.     

轴对称湍流射流流场的数值模拟

借助商业软件 CFX4.4,对 Laval 喷管外的射流流场进行数值模拟,分析讨论了不同滞止压力、环境温度对湍流射流轴中心线上流场的影响,对比以往模拟结果和实际现场氧枪操作曲线验证了是k-ε湍流模型在描述湍流射流流场方面的适用性.     

一种基于小波包分解的虹膜防伪检测方法

虹膜识别系统易受到伪虹膜的攻击,包括利用打印在隐形眼镜、玻璃眼或其他材料上的假虹膜纹理进行的攻击,所以检测出假虹膜的防伪算法至关重要。为此,提出一种利用小波包分解进行特征提取的虹膜防伪检测方法。首先对目标图像进行二级小波包分解,然后计算各子带图像的熵,最后将各子带图像的熵值之和作为提取的特征值。实验在包含500幅虹膜图像的数据库中进行,结果表明此方法可以有效地将真假虹膜区分开来。