Objective To explore the distribution and characteristics of initial PSA and PSA velocity in men younger than years without prostate cancer. Methods PSA in men younger than 50 years without prostate cancer from Januar...Objective To explore the distribution and characteristics of initial PSA and PSA velocity in men younger than years without prostate cancer. Methods PSA in men younger than 50 years without prostate cancer from January 2001 to November 2009 were retrieved retrospec-展开更多
The characteristics of fatigue crack initiation in Ti-5AI-4Sn-2Zr1Mo-O.7Nd-O.25Si alloy wereStudied. Two modes Of fatigue crack initiation were found. The Nd-rich phase particles displaybetter resistance to fatigue cr...The characteristics of fatigue crack initiation in Ti-5AI-4Sn-2Zr1Mo-O.7Nd-O.25Si alloy wereStudied. Two modes Of fatigue crack initiation were found. The Nd-rich phase particles displaybetter resistance to fatigue crack initiation than the matrix at lower stress.展开更多
In this paper,the flow field characteristics of Oblique Detonation Waves(ODWs)induced by a finite wedge under argon dilution are studied by solving the Euler equations with a detailed chemical model of hydrogen and ai...In this paper,the flow field characteristics of Oblique Detonation Waves(ODWs)induced by a finite wedge under argon dilution are studied by solving the Euler equations with a detailed chemical model of hydrogen and air.First,the effects of the expansion waves,argon concentration,geometric parameters,and Mach number on the ODW are discussed.The results show that the changes of these parameters may make the oblique detonation not be initiated.Then,the ODW initiation criterion of the finite wedge is summarized,as the characteristic length of the induction zone LCand the characteristic length of the oblique wedge LWmeet the condition LC/LW<1,the initiation of the ODW occurs;otherwise,it does not occur.What’s more,the Constant Volume Combustion(CVC)theory is applied to study the characteristic length of induction zone.It is found that CVC theory is more suitable for the“smooth transition”type of ODW flow field,the theoretical and numerical characteristic length in induction regions are in good agreement.This work is of great significance for the design of oblique detonation engines for hypersonic vehicles.展开更多
The CSU-RAMS-2A was used to simulate the meteorological fields over the Zhujiang River Delta in South China. Initialized from a horizontally homogeneous atmosphere,real topography and inhomogeneous surface boundary co...The CSU-RAMS-2A was used to simulate the meteorological fields over the Zhujiang River Delta in South China. Initialized from a horizontally homogeneous atmosphere,real topography and inhomogeneous surface boundary condi- tions,the model was run with thermal and terrain forcing.The modeling results of winter and summer cases are com- pared with those observed.The similarity of the predicted distributions of winds,temperatures and humidities to the ob- served patterns permits us to conclude that the mesoscale distribution of meteorological elements for the two study dates is the result of the thermal and dynamical forcing by the underlying surface and topography.展开更多
文摘Objective To explore the distribution and characteristics of initial PSA and PSA velocity in men younger than years without prostate cancer. Methods PSA in men younger than 50 years without prostate cancer from January 2001 to November 2009 were retrieved retrospec-
文摘The characteristics of fatigue crack initiation in Ti-5AI-4Sn-2Zr1Mo-O.7Nd-O.25Si alloy wereStudied. Two modes Of fatigue crack initiation were found. The Nd-rich phase particles displaybetter resistance to fatigue crack initiation than the matrix at lower stress.
基金supported by the Fundamental Research Funds for the Central Universities of China(No.310201906zy009)the Basic Research Plan of Natural Science in Shanxi Province—General Project(Youth),China(No.2019JQ-132)。
文摘In this paper,the flow field characteristics of Oblique Detonation Waves(ODWs)induced by a finite wedge under argon dilution are studied by solving the Euler equations with a detailed chemical model of hydrogen and air.First,the effects of the expansion waves,argon concentration,geometric parameters,and Mach number on the ODW are discussed.The results show that the changes of these parameters may make the oblique detonation not be initiated.Then,the ODW initiation criterion of the finite wedge is summarized,as the characteristic length of the induction zone LCand the characteristic length of the oblique wedge LWmeet the condition LC/LW<1,the initiation of the ODW occurs;otherwise,it does not occur.What’s more,the Constant Volume Combustion(CVC)theory is applied to study the characteristic length of induction zone.It is found that CVC theory is more suitable for the“smooth transition”type of ODW flow field,the theoretical and numerical characteristic length in induction regions are in good agreement.This work is of great significance for the design of oblique detonation engines for hypersonic vehicles.
基金supported by the Guangdong Basic and Applied Basic research Foundation (Grant No.2022A1515011565)Foundation of State Key Laboratory of High Temperature Gas Dynamics (Grant No.2021KF10)the China Postdoctoral Science Foundation (Grant Nos.2021M692633 and 2022T150534).
文摘The CSU-RAMS-2A was used to simulate the meteorological fields over the Zhujiang River Delta in South China. Initialized from a horizontally homogeneous atmosphere,real topography and inhomogeneous surface boundary condi- tions,the model was run with thermal and terrain forcing.The modeling results of winter and summer cases are com- pared with those observed.The similarity of the predicted distributions of winds,temperatures and humidities to the ob- served patterns permits us to conclude that the mesoscale distribution of meteorological elements for the two study dates is the result of the thermal and dynamical forcing by the underlying surface and topography.
