The superconducting RF cavity and superconducting magnet are the key devices in modern accelerators. With the development of accelerator technology and requirement of higher beam energy and luminosity,the cryogenic an...The superconducting RF cavity and superconducting magnet are the key devices in modern accelerators. With the development of accelerator technology and requirement of higher beam energy and luminosity,the cryogenic and superconducting technologies are applied widely in the accelerator construction.Based on the study of several typical accelerators which adopted cryogenic and superconducting technology,this paper introduces the recent activities of cryogenic system in overseas and domestic accelerators.展开更多
The implementation of parameter estimation is a serious problem in the modeling for nonlinear simultaneous equations.For the estimator of best nonlinear two stage least squares(BNL2SLS)that Amemiya proposed,the proced...The implementation of parameter estimation is a serious problem in the modeling for nonlinear simultaneous equations.For the estimator of best nonlinear two stage least squares(BNL2SLS)that Amemiya proposed,the procedure of selecting matrix(W)of instrumental variables is presented, which is based on the calculation of alternating conditional expectation.The algorithm of BNL2SLS estimator is explored which is recommended by two steps,and its efficiency is confirmed in simulation study.It has bred prospects to apply the algorithm proposed in this paper in practice.展开更多
文摘目的探讨琥珀酸脱氢酶复合物亚单位A(SDHA)对小鼠肝细胞BNL CL.2细胞增殖、细胞周期和凋亡的影响。方法用慢病毒载体介导的sh RNA敲低BNL CL.2细胞中sdha基因的表达。流式细胞仪检测慢病毒的感染效率;实时荧光定量PCR和Western蛋白印迹法分别检测sdha m RNA和SDHA蛋白表达水平;细胞计数法检测细胞增殖;流式细胞术检测细胞凋亡和细胞周期。结果无相关sh RNA对照组和sdha sh RNA组慢病毒的感染效率均>80%。与无相关sh RNA对照组相比,感染sdha sh RNA慢病毒载体的BNL CL.2细胞sdha m RNA水平降低20倍左右(P<0.01),蛋白表达水平降低10倍左右(P<0.01);细胞增殖速度减慢,为无相关sh RNA对照组的70%左右(P<0.05);细胞周期发生改变,G0/G1期细胞百分率是无相关sh RNA对照组的1.17倍(P<0.01),G2/M期细胞百分率为1.37倍(P<0.01),S期细胞百分率为73.8%(P<0.01);但细胞凋亡率无明显差异。结论降低SDHA表达对小鼠肝细胞BNL CL.2细胞增殖有明显的抑制作用,其抑制作用与细胞周期阻滞相关,与细胞凋亡无明显关系。
文摘The superconducting RF cavity and superconducting magnet are the key devices in modern accelerators. With the development of accelerator technology and requirement of higher beam energy and luminosity,the cryogenic and superconducting technologies are applied widely in the accelerator construction.Based on the study of several typical accelerators which adopted cryogenic and superconducting technology,this paper introduces the recent activities of cryogenic system in overseas and domestic accelerators.
文摘The implementation of parameter estimation is a serious problem in the modeling for nonlinear simultaneous equations.For the estimator of best nonlinear two stage least squares(BNL2SLS)that Amemiya proposed,the procedure of selecting matrix(W)of instrumental variables is presented, which is based on the calculation of alternating conditional expectation.The algorithm of BNL2SLS estimator is explored which is recommended by two steps,and its efficiency is confirmed in simulation study.It has bred prospects to apply the algorithm proposed in this paper in practice.
