水切伦科夫探测器阵列(Water Cherenkov Detector Array,WCDA)是高海拔宇宙线观测站(Large High Altitude Air Shower Observatory,LHAASO)的主体探测器之一,水作为探测器的唯一探测介质,水的洁净度直接影响探测器对切伦科夫光的探测效...水切伦科夫探测器阵列(Water Cherenkov Detector Array,WCDA)是高海拔宇宙线观测站(Large High Altitude Air Shower Observatory,LHAASO)的主体探测器之一,水作为探测器的唯一探测介质,水的洁净度直接影响探测器对切伦科夫光的探测效率.为保证水切伦科夫探测器阵列物理目标的实现,水衰减长度的实时测量和监测至关重要,是探测器正常运行和标定的关键工作之一.分别介绍了水衰减长度测量装置和紫外可见分光光度计的工作原理,并通过不同波长的发光二极管(Light Emitting Diode,LED)对各种样品水进行测量,将两种方法的数据结果进行对比分析,得出两种装置的测量误差分别为0.22 m和0.18 m,以及工业指标吸光度与科研指标水衰减长度之间的对应关系,并为几何和跟踪(GEometry AND Tracking,GEANT4)模拟确定了一种Querry水质模型,进一步推进了模拟的真实化.通过对水切伦科夫探测器阵列1号水池水衰减测量装置的验证及从注水到稳定运行期间的水质监测的数据研究,总结了一套稳定可靠的水质监测方案,为2、3号水池的监测工作奠定了良好的基础.展开更多
Rupture directivity effect causes spatial variation in strong ground motion parameters. It causes difference between the strike- normal （V.） and strike-parallel （Vp） components of horizontal ground motion amplitud...Rupture directivity effect causes spatial variation in strong ground motion parameters. It causes difference between the strike- normal （V.） and strike-parallel （Vp） components of horizontal ground motion amplitudes. These variations become significant for strong ground motion velocity and the authors have developed a modification to define directivity effect factor to account for the effect of rupture directivity in empirical velocity attenuation relations which are based on modeling Silakhor earthquake, using finite element method by ANSYS. The ground motion parameters that are modified include ratio of Vn/Vp component of horizontal velocity and Vn component to average horizontal velocity （V）. The ratio of Vn to Vp is large in both the forward directivity direction, where velocity is larger, and in the backward directivity direction, where velocity is smaller. Therefore the authors expected that the Vn/Vp was mainly controlled by directivity angle. Also the variation of fault normal velocity to average horizontal velocity ratio by directivity angle （0） is defined from earthquake modeling. It shows Vn/V is controlled by directivity angle, distance between the site, epicenter and rupture length. This ratio has the same trend in Silakhor earthquake strong ground velocity data. In this paper the equation for Vn/Vp variations by directivity angle is recommended. The authors used Somervill et al. （1997） directivity model parameters as （R/L） cos2 ~ to define directivity effect on Vn/V ratio and therefore directivity factor is determined to account in near field empirical strong ground velocity attenuation relationships.展开更多
文摘水切伦科夫探测器阵列(Water Cherenkov Detector Array,WCDA)是高海拔宇宙线观测站(Large High Altitude Air Shower Observatory,LHAASO)的主体探测器之一,水作为探测器的唯一探测介质,水的洁净度直接影响探测器对切伦科夫光的探测效率.为保证水切伦科夫探测器阵列物理目标的实现,水衰减长度的实时测量和监测至关重要,是探测器正常运行和标定的关键工作之一.分别介绍了水衰减长度测量装置和紫外可见分光光度计的工作原理,并通过不同波长的发光二极管(Light Emitting Diode,LED)对各种样品水进行测量,将两种方法的数据结果进行对比分析,得出两种装置的测量误差分别为0.22 m和0.18 m,以及工业指标吸光度与科研指标水衰减长度之间的对应关系,并为几何和跟踪(GEometry AND Tracking,GEANT4)模拟确定了一种Querry水质模型,进一步推进了模拟的真实化.通过对水切伦科夫探测器阵列1号水池水衰减测量装置的验证及从注水到稳定运行期间的水质监测的数据研究,总结了一套稳定可靠的水质监测方案,为2、3号水池的监测工作奠定了良好的基础.
文摘Rupture directivity effect causes spatial variation in strong ground motion parameters. It causes difference between the strike- normal （V.） and strike-parallel （Vp） components of horizontal ground motion amplitudes. These variations become significant for strong ground motion velocity and the authors have developed a modification to define directivity effect factor to account for the effect of rupture directivity in empirical velocity attenuation relations which are based on modeling Silakhor earthquake, using finite element method by ANSYS. The ground motion parameters that are modified include ratio of Vn/Vp component of horizontal velocity and Vn component to average horizontal velocity （V）. The ratio of Vn to Vp is large in both the forward directivity direction, where velocity is larger, and in the backward directivity direction, where velocity is smaller. Therefore the authors expected that the Vn/Vp was mainly controlled by directivity angle. Also the variation of fault normal velocity to average horizontal velocity ratio by directivity angle （0） is defined from earthquake modeling. It shows Vn/V is controlled by directivity angle, distance between the site, epicenter and rupture length. This ratio has the same trend in Silakhor earthquake strong ground velocity data. In this paper the equation for Vn/Vp variations by directivity angle is recommended. The authors used Somervill et al. （1997） directivity model parameters as （R/L） cos2 ~ to define directivity effect on Vn/V ratio and therefore directivity factor is determined to account in near field empirical strong ground velocity attenuation relationships.
