Change trend of temperature in the Songhua River Basin during the past 51 years

利用1958～2008年松花江流域34个气象站的日温度数据,采用滑动平均法、Mann-Kendall非参数检验、突变法和森斜率估计法,定量地分析了松花江流域年平均温度和季节温度的年际变化、变化趋势及变化幅度。研究结果表明,1958～2008年间松花江流域年平均温度表现为显著的上升趋势,51年来共上升了2℃,上升趋势在1990年发生了显著的突变。在季节变化方面,1958～2008年间松花江流域冬季平均温度上升幅度最大,达到0.06℃/a,夏季平均温度上升的幅度最小,仅为0.03℃/a。松花江流域的年和四季的增温幅度远远高于全国和全球水平。因此,应采取积极措施应对气候变化带来的不利影响

Quantification of Impacts of Precipitation Change and Human Activities on Streamflow in the Yanhe River Basin

利用Mann-Kendall突变检验法对延河流域1952—2008年降水量与甘谷驿站径流量进行分析,并以1952—1994年为基准期,定量分析1995—2008年降水变化和人类活动对径流的影响。结果表明:57年来延河流域正常降水发生概率达80.7%,径流年型以偏枯和枯水年为主;年降水量和径流量均呈减少趋势,突变分别发生在1995和2005年;与1952—1994年相比,1995—2008年的降水量和径流量较基准期分别减少11.1%和27.3%;降水变化和人类活动对径流减少的贡献率分别为46.2%和53.8%

Methodology of Dynamic Monitoring Gully Erosion Process Using 3D Laser Scanning Technology

在介绍三维激光扫描技术基本原理的基础上,详述了应用三维激光扫描技术实现沟蚀发育过程动态监测的方法和流程,包括扫描测量前期准备、扫描测量、点云预处理、坐标转换、TIN及等高线的生成、侵蚀量的估算等。以沟蚀发育过程的模拟降雨试验为案例,介绍了应用三维激光扫描技术进行沟蚀发育过程动态监测的方法,包括实地数据采集、点云分析处理和建模等,并分析了本案例基于三维激光扫描技术估算侵蚀量的精度,其平均精度达到96.85%。建议在野外应用三维激光扫描技术动态监测沟蚀过程时结合GPS进行辅助测量

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies