SUMMARYIn this study, two dimensional parabolic collectors with tubular absorber are systematically analyzed. For more effective practical design, modifications are made in the profile of the collector, for example, truncating the reflector to a lower height, making a gap between the absorber and the reflector, maintaining a vacuum space inside the collector, and so on. By using ray tracing method, a numerical model is developed to study the performance of the modified collector. In the analysis, Beijing city is taken as one basic case; the collector orientation effect is discussed in a quantitative way. It is found that east-west orientation is best for the current collector. Seasonal collector performances are carefully simulated for different latitude conditions in this study. The results indicate that it is better to regulate the collector once in a season. The optimal collector slope angles for different periods are also identified in this study.

EHD micro-jet can deposit rule and functional patterns in a direct, continuous and controllable manner, and has the advantages of good compatibility, high resolution and simple structure, thus becoming a cost-effective and high-efficiency technology. Through numerical method, obtain the three dimensional model of cone-jet and emphasize the correlation of sediment diameter and PEO concentration. The theoretical graphics agree well with the experimental data, which can explain and provide some theoretical basis for the experiments.

Anilox is the most important part in flexography, we simplified the structure of anilox roller into an axisymmetric trapezoidal groove, while established a numerical simulation of the ink transfer process by using the finite element method. We had done research on ink transfer characteristics in the flexographic printing process. The ink transfer ratio decreased when the upper plate contact angle increased, while increased when the dovetail groove contact angle increased; the aspect ratio also have impacts on the ink transfer.

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cryopreservation of cord blood hematopoetic stem cells. The recovered cells' viability was tested by typan blue staining, and the effect of EG group was best. The same result get from the recovery rate tested by MNC counted and receiver rate of CFU-GM. The result of the test of CFU-S showed that the effect of EG was better than DMSO (P < 0.05) and the diameter of CFU-S in EG group was the highest (P < 0.05), either about the WBC count in the peripheral blood of mouse (P < 0.05). These result suggest that the effects of protection were best when EG was composed of 1.5 M EG+ 0.25 M Suc + 1% Dex-40 in the vitrification cryopreservation of hematopoetic stem cells.In order to explore the chemotherapeutic sensitivity of brain tumor stem cells (BTSCs), we obtained fresh specimens of astrocytoma and then cultivated them primarily into BTSCs and brain tumor cells (BTCs). By drug S24Abstracts / Cell Biology International 32 (2008) S1eS67