Because of good quality of compressive resistance, the hyperbolic arch dam is being increasingly applied to engineering projects. In order to satisfy the needs of compressive resistance under the conditions of high wa...Because of good quality of compressive resistance, the hyperbolic arch dam is being increasingly applied to engineering projects. In order to satisfy the needs of compressive resistance under the conditions of high water pressure, a stress analysis is required for the dam. During the stress analysis process however, due to the complexity of the three-dimensional modeling, it is very hard to form a model. Therefore, the stress analysis process is a barrier for the arch dam. In this article, based on the research of the new line-type arch dam, a mathematical model in different degree of convexity conditions of the dam is established; using the C ＋ ＋ language program, a computer three-dimensional model simulation is realized on AutoCAD. The accurate three-dimensional model is providing a finite element optimization design of the involute hyperbolic arch dam for the next step.展开更多
With a view of studying programmed cell death （PCD） in a halophytic plant at the molecular level, we report here that apop-totic-like changes are induced by NaCl stress in Thellungiella halophila. The dose of 300 mM...With a view of studying programmed cell death （PCD） in a halophytic plant at the molecular level, we report here that apop-totic-like changes are induced by NaCl stress in Thellungiella halophila. The dose of 300 mM NaCl induced some apoptotic-like features in Thellungiella halophila cells, including the retraction of the plasma membrane from the cell wall, nuclear condensation, DNA laddering and the release of cytochrome c accompanying the increase of caspase 3-like protease activity. This process re-sulted in ultrastructural changes of mitochondria and Golgi bodies, and the appearance of autophagic vacuoles. This suggests that T. halophila suspension cell culture is an ideal system for studying severe salt stress-induced plant PCD. The results indicate that 300 mM NaCl stress-induced programmed cell death in T. halophila cells is similar to apoptosis and mitochondria play an impor-tant role in the early stage of plant PCD.展开更多
A mathematical model of optimization for cargo hold structure of small and medium-sized duplex stainless steel (DSS) chemical tankers based on the rule is described.The weight of DSS is defined as the objective functi...A mathematical model of optimization for cargo hold structure of small and medium-sized duplex stainless steel (DSS) chemical tankers based on the rule is described.The weight of DSS is defined as the objective function.The explicit formulas of the relevant rules,the explicit geometric relations formed by the structural arrangement and the implicit constraints such as layout,lines,expert experience,workmanship and so on are taken as the constraints.The design variables and the algorithm are determined by analyzing the logical relations among the factors.Besides,the efficiency of the optimum algorithm is improved by utilizing the distribution law of the optimal corrugations.Finally,the comprehensive optimization of the cargo hold DSS is accomplished by C++ programming.The weight of the optimized scheme of the example is 4.93% lower than that of the original scheme.The finite element analysis results show that the optimized scheme is satisfied with the requirements of the rules and has a good structure performance.The optimization method based on the rules and accomplished by the programming is practical for structural preliminary design.展开更多
基金Supported by Postgraduate Education Innovation Fund of Chongqing Jiaotong University
文摘Because of good quality of compressive resistance, the hyperbolic arch dam is being increasingly applied to engineering projects. In order to satisfy the needs of compressive resistance under the conditions of high water pressure, a stress analysis is required for the dam. During the stress analysis process however, due to the complexity of the three-dimensional modeling, it is very hard to form a model. Therefore, the stress analysis process is a barrier for the arch dam. In this article, based on the research of the new line-type arch dam, a mathematical model in different degree of convexity conditions of the dam is established; using the C ＋ ＋ language program, a computer three-dimensional model simulation is realized on AutoCAD. The accurate three-dimensional model is providing a finite element optimization design of the involute hyperbolic arch dam for the next step.
基金supported by grants from National Natural Science Foundation of China (30870425)
文摘With a view of studying programmed cell death （PCD） in a halophytic plant at the molecular level, we report here that apop-totic-like changes are induced by NaCl stress in Thellungiella halophila. The dose of 300 mM NaCl induced some apoptotic-like features in Thellungiella halophila cells, including the retraction of the plasma membrane from the cell wall, nuclear condensation, DNA laddering and the release of cytochrome c accompanying the increase of caspase 3-like protease activity. This process re-sulted in ultrastructural changes of mitochondria and Golgi bodies, and the appearance of autophagic vacuoles. This suggests that T. halophila suspension cell culture is an ideal system for studying severe salt stress-induced plant PCD. The results indicate that 300 mM NaCl stress-induced programmed cell death in T. halophila cells is similar to apoptosis and mitochondria play an impor-tant role in the early stage of plant PCD.
文摘A mathematical model of optimization for cargo hold structure of small and medium-sized duplex stainless steel (DSS) chemical tankers based on the rule is described.The weight of DSS is defined as the objective function.The explicit formulas of the relevant rules,the explicit geometric relations formed by the structural arrangement and the implicit constraints such as layout,lines,expert experience,workmanship and so on are taken as the constraints.The design variables and the algorithm are determined by analyzing the logical relations among the factors.Besides,the efficiency of the optimum algorithm is improved by utilizing the distribution law of the optimal corrugations.Finally,the comprehensive optimization of the cargo hold DSS is accomplished by C++ programming.The weight of the optimized scheme of the example is 4.93% lower than that of the original scheme.The finite element analysis results show that the optimized scheme is satisfied with the requirements of the rules and has a good structure performance.The optimization method based on the rules and accomplished by the programming is practical for structural preliminary design.
