Methodology for the reliability analysis of hydraulic gravity dam is the key technology in current hydropower construction.Reliability analysis for the dynamical dam safety should be divided into two phases:failure mo...Methodology for the reliability analysis of hydraulic gravity dam is the key technology in current hydropower construction.Reliability analysis for the dynamical dam safety should be divided into two phases:failure mode identification and the calculation of the failure probability.Both of them are studied based on the mathematical statistics and structure reliability theory considering two kinds of uncertainty characters(earthquake variability and material randomness).Firstly,failure mode identification method is established based on the dynamical limit state system and verified through example of Koyna Dam so that the statistical law of progressive failure process in dam body are revealed; Secondly,for the calculation of the failure probability,mathematical model and formula are established according to the characteristics of gravity dam,which include three levels,that is element failure,path failure and system failure.A case study is presented to show the practical application of theoretical method and results of these methods.展开更多
The charged lepton flavor violation process is a clean and sensitive probe of new physics beyond the Standard Model. A sensitivity study is performed to the process τ^-→γμ^- based on a 3 fb^(-1) inclusive Monte Ca...The charged lepton flavor violation process is a clean and sensitive probe of new physics beyond the Standard Model. A sensitivity study is performed to the process τ^-→γμ^- based on a 3 fb^(-1) inclusive Monte Carlo sample of e^+e^- collisions at a center-of-mass energy of4.26 or 4.6 Ge V, in the framework of the BESIII software system. The 90 % confidence level upper limits on B(τ^-→γμ^-) are estimated assuming no signal is produced. We also obtain the sensitivity on B(τ^-→γμ^-) as a function of the integrated luminosity, to serve as a reference for the HIEPA being proposed in China. It is found that 6.34 ab^(-1) are needed to reach the current best upper limit of 4:4 10^(-8) and about 2510 ab^(-1) are needed to reach a sensitivity of 10^(-9) if the detector design is similar to that of BESIII.展开更多
基金Projects(51021004,51379141)supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China
文摘Methodology for the reliability analysis of hydraulic gravity dam is the key technology in current hydropower construction.Reliability analysis for the dynamical dam safety should be divided into two phases:failure mode identification and the calculation of the failure probability.Both of them are studied based on the mathematical statistics and structure reliability theory considering two kinds of uncertainty characters(earthquake variability and material randomness).Firstly,failure mode identification method is established based on the dynamical limit state system and verified through example of Koyna Dam so that the statistical law of progressive failure process in dam body are revealed; Secondly,for the calculation of the failure probability,mathematical model and formula are established according to the characteristics of gravity dam,which include three levels,that is element failure,path failure and system failure.A case study is presented to show the practical application of theoretical method and results of these methods.
基金the National Natural Science Foundation of China (11235011)the National Basic Research Program of China (2015CB856701)CAS Center for Excellence in Particle Physics (CCEPP)
文摘The charged lepton flavor violation process is a clean and sensitive probe of new physics beyond the Standard Model. A sensitivity study is performed to the process τ^-→γμ^- based on a 3 fb^(-1) inclusive Monte Carlo sample of e^+e^- collisions at a center-of-mass energy of4.26 or 4.6 Ge V, in the framework of the BESIII software system. The 90 % confidence level upper limits on B(τ^-→γμ^-) are estimated assuming no signal is produced. We also obtain the sensitivity on B(τ^-→γμ^-) as a function of the integrated luminosity, to serve as a reference for the HIEPA being proposed in China. It is found that 6.34 ab^(-1) are needed to reach the current best upper limit of 4:4 10^(-8) and about 2510 ab^(-1) are needed to reach a sensitivity of 10^(-9) if the detector design is similar to that of BESIII.
