利用蒙特卡罗方法,模拟计算了不同线性能量传输(liner energy transfer,LET)的重离子在碳化硅中的能量损失,模拟结果表明:重离子在碳化硅中单位深度的能量损失受离子能量和入射深度共同影响;能量损失主要由初级重离子和次级电子产生,非...利用蒙特卡罗方法,模拟计算了不同线性能量传输(liner energy transfer,LET)的重离子在碳化硅中的能量损失,模拟结果表明:重离子在碳化硅中单位深度的能量损失受离子能量和入射深度共同影响;能量损失主要由初级重离子和次级电子产生,非电离能量损失只占总能量损失的1%左右;随着LET的增大,次级电子的初始角度和能量分布越来越集中;重离子诱导产生的电荷沉积峰值位置在重离子径迹中心,在垂直于入射深度方向上呈高斯线性减小分布.利用锎源进行碳化硅MOSFET单粒子烧毁试验,结合TCAD模拟得到不同漏极电压下器件内部电场分布,在考虑电场作用的蒙特卡罗模拟中发现:碳化硅MOSFET外延层的电场强度越大,重离子受电场作用在外延层运动的路径越长、沉积能量越多,次级电子越容易偏向电场方向运动导致局部能量沉积过高.展开更多
Due to the direct statistical interpretation,censored linear regression offers a valuable complement to the Cox proportional hazards regression in survival analysis.We propose a rank-based high-dimensional inference f...Due to the direct statistical interpretation,censored linear regression offers a valuable complement to the Cox proportional hazards regression in survival analysis.We propose a rank-based high-dimensional inference for censored linear regression without imposing any moment condition on the model error.We develop a theory of the high-dimensional U-statistic,circumvent challenges stemming from the non-smoothness of the loss function,and establish the convergence rate of the regularized estimator and the asymptotic normality of the resulting de-biased estimator as well as the consistency of the asymptotic variance estimation.As censoring can be viewed as a way of trimming,it strengthens the robustness of the rank-based high-dimensional inference,particularly for the heavy-tailed model error or the outlier in the presence of the response.We evaluate the finite-sample performance of the proposed method via extensive simulation studies and demonstrate its utility by applying it to a subcohort study from The Cancer Genome Atlas(TCGA).展开更多
In this study,the production of inclusive b-jet and bb dijets in Pb+Pb collisions has been investigated byconsidering the in-medium evolution of heavy and light quarks simultaneously.The initial hard processes of incl...In this study,the production of inclusive b-jet and bb dijets in Pb+Pb collisions has been investigated byconsidering the in-medium evolution of heavy and light quarks simultaneously.The initial hard processes of inclusiveb-jet and bb production are described using a next-to-leading order(NLO)plus parton shower Monte Carlo(MC)event generator,SHERPA,which can be well matched with the experimental data in p+p collisions.Theframework uses the Langevin transport model to describe the evolution of the bottom quark.Furthermore,the collisionalenergy loss and higher-twist description are considered to determine the radiative energy loss from both thebottom and light quarks.We compare the theoretical simulation of the inclusive jet and b-jet RAA in the Pb+Pb collisionsat√SNN=2:76 TeV with the experimental data and present the theoretical simulation of the momentum balanceof the bb dijet in the Pb+Pb collisions at 5.02 TeV along with recent CMS data for the first time.A similartrend to that seen in inclusive dijets is observed in bb dijets;the distribution of the production shifts to smaller xJ owingto the jet quenching effect.Finally,we report the prediction of the normalized azimuthal angle distribution of the bb dijet in the Pb+Pb collisions at 5.02 TeV.The medium-induced energy loss effect of the bb dijets will generallysuppress its production;however,the same side(ΔФ→0 region)suffers more energy loss than the far side(ΔФ→πregion),thus leading to suppression on the same side and enhancement on the far side in the normalized azimuthalangle distribution in A+A collisions.展开更多
文摘利用蒙特卡罗方法,模拟计算了不同线性能量传输(liner energy transfer,LET)的重离子在碳化硅中的能量损失,模拟结果表明:重离子在碳化硅中单位深度的能量损失受离子能量和入射深度共同影响;能量损失主要由初级重离子和次级电子产生,非电离能量损失只占总能量损失的1%左右;随着LET的增大,次级电子的初始角度和能量分布越来越集中;重离子诱导产生的电荷沉积峰值位置在重离子径迹中心,在垂直于入射深度方向上呈高斯线性减小分布.利用锎源进行碳化硅MOSFET单粒子烧毁试验,结合TCAD模拟得到不同漏极电压下器件内部电场分布,在考虑电场作用的蒙特卡罗模拟中发现:碳化硅MOSFET外延层的电场强度越大,重离子受电场作用在外延层运动的路径越长、沉积能量越多,次级电子越容易偏向电场方向运动导致局部能量沉积过高.
基金supported by National Natural Science Foundation of China(Grant No.12071483)。
文摘Due to the direct statistical interpretation,censored linear regression offers a valuable complement to the Cox proportional hazards regression in survival analysis.We propose a rank-based high-dimensional inference for censored linear regression without imposing any moment condition on the model error.We develop a theory of the high-dimensional U-statistic,circumvent challenges stemming from the non-smoothness of the loss function,and establish the convergence rate of the regularized estimator and the asymptotic normality of the resulting de-biased estimator as well as the consistency of the asymptotic variance estimation.As censoring can be viewed as a way of trimming,it strengthens the robustness of the rank-based high-dimensional inference,particularly for the heavy-tailed model error or the outlier in the presence of the response.We evaluate the finite-sample performance of the proposed method via extensive simulation studies and demonstrate its utility by applying it to a subcohort study from The Cancer Genome Atlas(TCGA).
基金Supported by Natural Science Foundation of China(11935007,11805167)。
文摘In this study,the production of inclusive b-jet and bb dijets in Pb+Pb collisions has been investigated byconsidering the in-medium evolution of heavy and light quarks simultaneously.The initial hard processes of inclusiveb-jet and bb production are described using a next-to-leading order(NLO)plus parton shower Monte Carlo(MC)event generator,SHERPA,which can be well matched with the experimental data in p+p collisions.Theframework uses the Langevin transport model to describe the evolution of the bottom quark.Furthermore,the collisionalenergy loss and higher-twist description are considered to determine the radiative energy loss from both thebottom and light quarks.We compare the theoretical simulation of the inclusive jet and b-jet RAA in the Pb+Pb collisionsat√SNN=2:76 TeV with the experimental data and present the theoretical simulation of the momentum balanceof the bb dijet in the Pb+Pb collisions at 5.02 TeV along with recent CMS data for the first time.A similartrend to that seen in inclusive dijets is observed in bb dijets;the distribution of the production shifts to smaller xJ owingto the jet quenching effect.Finally,we report the prediction of the normalized azimuthal angle distribution of the bb dijet in the Pb+Pb collisions at 5.02 TeV.The medium-induced energy loss effect of the bb dijets will generallysuppress its production;however,the same side(ΔФ→0 region)suffers more energy loss than the far side(ΔФ→πregion),thus leading to suppression on the same side and enhancement on the far side in the normalized azimuthalangle distribution in A+A collisions.
