The paper presents a scheme of optimization of the cooling process of the gas turbine blade. As an optimization criterion has been taken into account on the outer surface temperature of the blade. Inverse problem is s...The paper presents a scheme of optimization of the cooling process of the gas turbine blade. As an optimization criterion has been taken into account on the outer surface temperature of the blade. Inverse problem is solved for stationary heat conduction in which beside the optimization criterion of the heat transfer coefficient on the outer surface of the blade the temperature distribution is known, and the values sought are the heat transfer coefficients and surface temperature of the cooling channels. This problem was solved by the boundary element method using SVD algorithm and Tikhonov regularization. The temperature and heat transfer coefficient of cooling channels obtained from the inverse problem was oscillating in nature. This solution is nonphysical, so the heat transfer coefficients on the surface of cooling channels were averaged. Then the problem was solved simply with averaged coefficients of heat transfer on the surface of the cooling channels and the known distribution on the outer surface of blade. The temperature distribution obtained from the solution of direct problem with averaged values of heat transfer coefficient was compared with the criterion of optimization.The calculation results obtained using the SVD algorithm gave the temperature distribution on the external wall of the blade closer to the criterion of optimization.展开更多
The experiment was designed to study the preparation, cryopreservation and culture of calf spermatogonial stem cells in order to provide some data for theoretical research and practical use of calf spermatogonial stem...The experiment was designed to study the preparation, cryopreservation and culture of calf spermatogonial stem cells in order to provide some data for theoretical research and practical use of calf spermatogonial stem cells. As for enzymolysis of testis tissue, two digestive method A and B. The cryopreservation cooling procedure was that spermatogonial stem cells was equilibrated at 4℃ for lh, at -20℃ for lh, at -40℃ for 2h, at -80℃ overnight and then stored in liquid nitrogen. The different concentration of three eryoprotectants were compared. The results indicated that both method A and method B achieved the same high motility rates of cells with method B needing time longer, calf spermatogonial stem cells could be well cryopreserved by the stage cooling procedure. Satisfactory cryopreservative results were gotten by adding 10% DMSO or 10% EG to cryopreservative medium, the former was better and adding sucrose could improved cryopreservative effect. The culture behaviors of spermatogonial stem cells kept the same before and after cryopreservation. It was concluded that an effective method was verified for preparation, cryopreservation and culture of new calf spermatogonial stem cells.展开更多
文摘The paper presents a scheme of optimization of the cooling process of the gas turbine blade. As an optimization criterion has been taken into account on the outer surface temperature of the blade. Inverse problem is solved for stationary heat conduction in which beside the optimization criterion of the heat transfer coefficient on the outer surface of the blade the temperature distribution is known, and the values sought are the heat transfer coefficients and surface temperature of the cooling channels. This problem was solved by the boundary element method using SVD algorithm and Tikhonov regularization. The temperature and heat transfer coefficient of cooling channels obtained from the inverse problem was oscillating in nature. This solution is nonphysical, so the heat transfer coefficients on the surface of cooling channels were averaged. Then the problem was solved simply with averaged coefficients of heat transfer on the surface of the cooling channels and the known distribution on the outer surface of blade. The temperature distribution obtained from the solution of direct problem with averaged values of heat transfer coefficient was compared with the criterion of optimization.The calculation results obtained using the SVD algorithm gave the temperature distribution on the external wall of the blade closer to the criterion of optimization.
文摘The experiment was designed to study the preparation, cryopreservation and culture of calf spermatogonial stem cells in order to provide some data for theoretical research and practical use of calf spermatogonial stem cells. As for enzymolysis of testis tissue, two digestive method A and B. The cryopreservation cooling procedure was that spermatogonial stem cells was equilibrated at 4℃ for lh, at -20℃ for lh, at -40℃ for 2h, at -80℃ overnight and then stored in liquid nitrogen. The different concentration of three eryoprotectants were compared. The results indicated that both method A and method B achieved the same high motility rates of cells with method B needing time longer, calf spermatogonial stem cells could be well cryopreserved by the stage cooling procedure. Satisfactory cryopreservative results were gotten by adding 10% DMSO or 10% EG to cryopreservative medium, the former was better and adding sucrose could improved cryopreservative effect. The culture behaviors of spermatogonial stem cells kept the same before and after cryopreservation. It was concluded that an effective method was verified for preparation, cryopreservation and culture of new calf spermatogonial stem cells.
