The pressurized water reactor CAP1400 is one of the sixteen National Science and Technology Major Projects. Developed from China＇s nuclear R＆D system and manufacturing capability, as well as APIO00 technology introd...The pressurized water reactor CAP1400 is one of the sixteen National Science and Technology Major Projects. Developed from China＇s nuclear R＆D system and manufacturing capability, as well as APIO00 technology introduction and assimilation, CAP1400 is an advanced large passive nuclear power plant with independent intellectual property rights. By discussing the top design principle, main performance objectives, general parameters, safety design, and important improvements in safety, economy, and oth- er advanced features, this paper reveals the technology innovation and competitiveness of CAP1400 as an internationally promising Gen-IIl PWR model. Moreover, the R＆D of CAP1400 has greatly promoted China＇s domestic nuclear power industry from the Gen-II to the Gen-III level.展开更多
In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government＇ s leading role cannot give a better play du...In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government＇ s leading role cannot give a better play due to the constraints of the traditional government functions. Therefore, it is necessary to carry out a reasonable position for the government functions in the construction of smart city. This paper issues that the government should reflect functions in the construction of smart city, such as the planning function of top-level design and unified planning; the organizational function of providing funds and talent protection; the coordinating function of promoting multiple-subject cooperation; the controlling function of establishing technical standards and legal norms.展开更多
In this paper, form vulnerability theory was applied to the analysis of the failure mechanisms of single-layer latticed spherical shells subjected to seismic excitations. Three 1/10 scale testing models were designed ...In this paper, form vulnerability theory was applied to the analysis of the failure mechanisms of single-layer latticed spherical shells subjected to seismic excitations. Three 1/10 scale testing models were designed with characteristics as follows： Model 1 possesses overall uniform stiffness and is expected to collapse in the strength failure mode as some members become plastic; Model 2 possesses six man-made weak parts located on six radial main rib zones and is expected to collapse in the dynamic in- stability mode with all members still in the elastic stage; Model 3 strengthens the six weak zones of Model 2, and therefore, its stiffness is uniform. Model 3 is proposed to collapse in the strength failure mode when the members are still in the elastic stage By increasing the peak ground accelerations of seismic waves gradually, the shaking table tests were carried out until all three models collapsed （or locally collapsed）. On the basis of form vulnerability theory, topological hierarchy models of the test models were established through a clustering process, and various failure scenarios, including overall collapse scenarios and partial collapse scenarios, were identified by unzipping corresponding hierarchical models. By comparison of the failure scenarios based on theoretical analysis and experiments, it was found that vulnerability theory could effectively reflect the weak- ness zones in topological relations of the structures from the perspective of internal causes. The intemal mechanisms of the distinct failure characteristics of reticulated shells subjected to seismic excitations were also revealed in this process. The well-formedness of structural clusters, Q, is closely related to the collapse modes, i.e., uniform changes of Q indicate a uniform distribution of overall structural stiffness, which indicates that strength failure is likely to happen; conversely, non-uniform changes of Q indicate that weak zones exist in the structure, and dynamic instability is likely to occur.展开更多
文摘The pressurized water reactor CAP1400 is one of the sixteen National Science and Technology Major Projects. Developed from China＇s nuclear R＆D system and manufacturing capability, as well as APIO00 technology introduction and assimilation, CAP1400 is an advanced large passive nuclear power plant with independent intellectual property rights. By discussing the top design principle, main performance objectives, general parameters, safety design, and important improvements in safety, economy, and oth- er advanced features, this paper reveals the technology innovation and competitiveness of CAP1400 as an internationally promising Gen-IIl PWR model. Moreover, the R＆D of CAP1400 has greatly promoted China＇s domestic nuclear power industry from the Gen-II to the Gen-III level.
文摘In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government＇ s leading role cannot give a better play due to the constraints of the traditional government functions. Therefore, it is necessary to carry out a reasonable position for the government functions in the construction of smart city. This paper issues that the government should reflect functions in the construction of smart city, such as the planning function of top-level design and unified planning; the organizational function of providing funds and talent protection; the coordinating function of promoting multiple-subject cooperation; the controlling function of establishing technical standards and legal norms.
基金supported by the National Natural Science Foundation of China (Grant No. 90715005)the New Century Excellent Talent of Ministry of Education of China (Grant No. NCET-07-0186)the Doctoral Fund of Ministry of China (Grant No. 200802860007)
文摘In this paper, form vulnerability theory was applied to the analysis of the failure mechanisms of single-layer latticed spherical shells subjected to seismic excitations. Three 1/10 scale testing models were designed with characteristics as follows： Model 1 possesses overall uniform stiffness and is expected to collapse in the strength failure mode as some members become plastic; Model 2 possesses six man-made weak parts located on six radial main rib zones and is expected to collapse in the dynamic in- stability mode with all members still in the elastic stage; Model 3 strengthens the six weak zones of Model 2, and therefore, its stiffness is uniform. Model 3 is proposed to collapse in the strength failure mode when the members are still in the elastic stage By increasing the peak ground accelerations of seismic waves gradually, the shaking table tests were carried out until all three models collapsed （or locally collapsed）. On the basis of form vulnerability theory, topological hierarchy models of the test models were established through a clustering process, and various failure scenarios, including overall collapse scenarios and partial collapse scenarios, were identified by unzipping corresponding hierarchical models. By comparison of the failure scenarios based on theoretical analysis and experiments, it was found that vulnerability theory could effectively reflect the weak- ness zones in topological relations of the structures from the perspective of internal causes. The intemal mechanisms of the distinct failure characteristics of reticulated shells subjected to seismic excitations were also revealed in this process. The well-formedness of structural clusters, Q, is closely related to the collapse modes, i.e., uniform changes of Q indicate a uniform distribution of overall structural stiffness, which indicates that strength failure is likely to happen; conversely, non-uniform changes of Q indicate that weak zones exist in the structure, and dynamic instability is likely to occur.
