More and more attention is being paid to extrusion with multi-hole die in the manufacturing industry because of its advantages of high efficiency, high accuracy. However, there is a key factor that need to be taken into cosideration, such as diehole lacation on the multi-hole die. A optimization strategy integrated regression analysis for the multi-hole die design in profile extrusion process based on finite element simulation, GA, and regression theory was proposed, and an optimized model is established to predict the best location of diehole. A few examples show that the strategy is effective, feasible, and the model is accurate, applicable.

.The process for the desaltation of the polysaccharide from the mixotrophic liquid culture of Nostoc flagelliforme with radial flow chromatography (RFC) column packed with Sephadex G-100 gel was investigated. The RFC column having 7.7 cm of bed length and 229.6 cm3 of bed volume was used in this study. The effects of some operating factors such as the sampling weight, the flow rate of eluent on the desaltation efficiency were examined. It was found that the separation efficiency increases with the decrease of sampling weight and flow rate of eluent. With 2.4 mg of sampling weight and 0.3 ml/min of flow rate of eluent, the salt content of polysaccharide was lowered from 90.42% to 2.36%. As a conclusion, this technique can be used to get rid of the eluant in the polysaccharide introduced by the ion exchange process.

Wavelet transform was utilized in vibrant signal processing of air suspension system. A dynamic model of 1/4 engineering vehicle with air suspension system was established. Road surface signal of B grade was input to the dynamic model. Vibrant acceleration curve of under spring mass and dynamic load curve of air suspension was gained. Noise signal of under spring mass acceleration and dynamic load of air suspension system were filtrated by wavelet decomposition. Vibrant acceleration signal of under spring mass and dynamic load signal of air suspension were extracted by wavelet reconstruction. It can provide a theoretical foundation for identifying dynamic load of air suspension system.