The author measured TN, NH4+-N, NO2--N, NO3--N, TP, PO43--P and CODMn of the five aquaculture lakes that is, Liangzi Lake, Futou Lake, Chaipo Lake, Nanhu Lake and Yezhi Lake, in Wuhan in 2007, and had analyzed the results by means of Principal Component Analysis (PCA), Factor Analysis (FA) and Cluster Analysis (CA). The PCA result showed that the two principal components were nutrient factor (including TN, NO2--N, NO3--N, TP, PO43--P and CODMn) and ammonium absorption factor (NH4+-N), with their function expression integrated. The results of FA and PCA were in conformity, with their factor score function expression integrated. R-mode cluster result indicated that the seven hydrochemical indexes could be divided into four categories, i.e. NO3 - -N, TP, TN and NO2--N make up of one category, and another three categories were PO43--P, NH4+-N and CODMn, respectively. Q-mode cluster result showed that the five lakes can be divided into two categories, Futou Lake and Liangzi Lake is one category, and Chaipo Lake, Yezhi Lake and Nanhu Lake is the other, which has been caused by urban waste water, domestic sewage and aquaculture production.

This paper discussed the mechanism of internal fogging in automotive lamp based on the principle of water vapor condensation, and put forward the concept of the critical fogging humidity of lamp according to the structure and engineering characteristics. It given out a simple way to judge lamp fogging on the base of lamp temperature field, and verified the existence of the critical fog humidity by the test. All of these are very meaningful on the evaluation of the lamp's structure and raise the level of lamp design

An improved cooperative method to control a nonlinear uncertain system is raised in this paper. First, the optimal control law is introduced to attain the desired dynamics of the linear part of original system. Then, a nonlinear PI controller is used to remove the influence of uncertain unit. It is proved by simulation that this method is effective to control this special system and is easy to be carried in applications.

Due to large planar scale and small lateral scale of plastic drawing board, it was easy to cause warpage problem in injection molding. Optimization of injection molding process was taken to reduce residual stress and improve quality. Combining orthogonal experimental method and software Moldflow, analyzed the effect of mold temperature, melt temperature, hold pressure and injection velocity on warpage deformation. It changed multi-objective optimization to single-objective optimization by weighted method. Through range analysis obtained the influence trend between parameters and comprehensive optimal object. Lastly got the optimal combination of injection molding process parameters.