Upper-bound analysis of the pressure-assisted injection forging of thick-walled tubular components with hollow flanges

An upper-bound analysis of the pressure-assisted injection forging (PAIF) of thick-walled tubular components with hollow flanges was conducted to predict the maximum forming-pressure requirements. The polymeric pressurizing material and the pure aluminium work material employed were assumed to obey the von-Mises’ yield criterion, the two materials being divided into three and six zones, respectively, and described using kinematically admissible velocity fields. An upper-bound solution was derived based on this model. Experiments were conducted to validate the solution. The results suggest that the upper-bound analysis has sufficient accuracy for the prediction of the forming-pressure requirements. Subsequently, a parametric analysis was conducted to study the effects of variation of the principal parameters of the process and the geometry, such as tube thicknesses, flange dimensions and friction, on the forming-force requirements, which showed other useful applications of the upper-bound solutions.     

Generalized null space uncorrelated Fisher discriminant analysis for linear dimensionality reduction

We propose a generalized null space uncorrelated Fisher discriminant analysis (GNUFDA) technique integrating the uncorrelated discriminant analysis and weighted pairwise Fisher criterion. The GNUFDA can effectively deal with the small sample-size problem and perform satisfactorily when the dimensionality of the null space decreases with increase in the number of training samples per class and/or classes, C. The proposed GNUFDA can extract at most C-1 optimal uncorrelated discriminative vectors without being influenced by the null-space dimensionality.     

Spatially resolved infrared spectroscopy: a novel technique for in situ study of spatial surface coverage during CO oxidation on supported catalysts

A spatially resolved infrared (IR) imaging technique to monitor the linear adsorbed CO coverage on supported catalyst surface combining an IR bandpass filter and an IR thermography camera has been developed. Images acquired during the CO adsorption/desorption and ignition indicate that the technique provides an excellent method to image the change of surface coverage with a spatial resolution. It is expected that the combination of infrared thermography with spatially resolved imaging of surface coverage will provide a deeper insight in the dynamics of spatio-temporal patterns on heterogeneous catalysts.     

铸造高性能合金的显微组织及耐腐蚀行为

对铸造高性能合金Lewmet55进行了化学成分设计，确定了该合金中镍、铬、钼、铜和硅的含量。采用金相显微镜和X射线衍射相结合的方法，分析了该合金的显微组织，并采用多种腐蚀试验方法研究其耐腐蚀行为。着重研究了不同热处理制度对铸造高性能合金的均匀腐蚀、晶问腐蚀、点蚀和电化学腐蚀性能的影响。试验结果表明，Lewment55合金经1250℃×1．5h水冷固溶处理后，在高温浓硫酸介质中具有良好的耐蚀性，以及较好的抗晶间腐蚀、点蚀和电化学腐蚀性能。     

高层结构几何非线性分析的QR法

本文利用ＱＲ法分析高层建筑结构几何非线性问题，建立了新的计算格式。该法不仅未知量的数目少，精度高，而且输入简单，计算速度快，可以用微机分析复杂问题。     

Fischer-Tropsch synthesis on Fe-Mn ultrafine catalysts

The Fischer-Tropsch (FT) synthesis on Fe-Mn ultrafine catalysts prepared by a special degradation method of Fe-Mn complexes is presented. The effects of preparation method and Mn content on the FT performance are examined and the active phases and the role of Mn are elucidated.     

机油泵转子的研究

本文研究了有关机油泵转子的齿形曲线、测绘及型腔设计等几个问题     

计算机轧辊管理软件

使用计算机管理轧辊可以非常方便地查询每一条轧辊的材质、产地、车削情况使用情况及该辊的轧制产量等数据，并可根据要求打印表格或轧辊消耗报表。