基于结构水文地质学的采掘诱发高势能突水溃砂主动防控

在谷德振先生“水文地质结构”学术思想指引下,本文提出建立结构水文地质学的设想,论述了其基础理论框架。从方法论角度将矿山水害防控分为被动防控和主动防控两种方法。以结构水文地质学指导煤矿高势能突水溃砂防控,分析了被动防控可能产生突水溃砂灾害的机理; 提出了主动地质工程防控的原理,包括地质材料性质改造、结构隔水性能重构、赋存水动力环境改造、减轻采掘诱发覆岩破坏等具体方法。抛砖引玉,以期催生符合中国矿山防治水实践需要的创新理论和方法。     

利用小波阈值消噪改进M-W组合周跳探测性能

受伪距噪声的影响,Turbo Eidt法中M-W组合难以探测所有周跳。分析了M-W组合观测量的误差特性,指出伪距误差导致周跳漏检、探测延迟的原因。采用小波阈值消噪方法对M-W组合观测值进行处理,阈值估计使用Visushrink方法可削弱伪距噪声、增加周跳的辨识度。消噪后,周跳会发生扩散,除当前历元外,前后多个历元均会超出阈值,便于探测。实测数据结果表明:经小波消噪后的M-W组合观测值能够准确定位小至1周的所有周跳,避免漏检现象,增强周跳探测的可靠性。     

应用单历元模糊度算法解决实时GPS水汽探测技术中模糊度问题

首先简要介绍实时水汽探测技术的原理,然后采用详细的推算过程将求水汽量转化为求宽巷模糊度的问题,并利用双频P码求出宽巷模糊度。运用实例模拟分析双频P码求宽巷模糊度的精度,解释宽巷模糊度的精度随卫星高度角变化的原因。     

利用改进灰色模型的钟差预报算法及其精度分析

灰色模型在钟差长期预报中虽具有一定的优势,但是预测的精度还有进一步提高的可能。在本文中,采用经过数据预处理和残差修正对一阶灰色模型进行了改进,再对GPS卫星钟差进行不同时间尺度上的预报。算例利用IGS提供的精密钟差产品,建立了一个基于改进灰色模型的预报算法,改进灰色模型的预报精度较传统的二次项模型有了很大的提高,且预报结果的收敛性也获得了一定程度的改善。     

论地理国情监测的技术支撑

地理国情监测是新时期空间信息科学的重要使命。对地理国情监测的必要性和内容进行了讨论,逐一剖析了空天地一体化遥感技术、全球卫星导航定位技术、网格GIS技术、地理信息网络服务、多维时空数据挖掘技术、空间信息云计算技术等在地理国情监测中的地位和作用、面临的问题和发展建议,以期为全面实现地理国情的定期监测、日常监测和应急监测奠定技术基础。     

1961—2009年辽河流域水文气象要素变化特征

依据1961—2009年辽河流域5个气象观测站点逐日降水和气温观测资料,运用非参数检验方法（Mann-Kendall法）,对辽河流域降水和气温的变化趋势进行了分析。利用2006—2010年夏季共162d降水日的铁岭站日降水量与铁岭水文站径流量资料,探讨了日降水量与径流量之间的相关关系。结果表明：辽河流域年降水量减少趋势明显,降水量偏少年份明显增加,其主要原因为占全年降水量65%的夏季降水以7.4 mm/10 a的气候趋势倾向率递减,呈现出明显的减少趋势;辽河流域的年平均气温是在波动中逐渐上升的,且升温趋势明显,春季呈明显的升温趋势,夏季略有下降,秋季变化不大,冬季是气温上升最明显的季节;日降水量与径流量存在正相关关系,且日降水量与降水第二日的径流量相关显著。     

Monsoon Change in East Asia in the 21st Century: Results of RegCM3

The authors investigate monsoon change in East Asia in the 21st century under the Special Report on Emissions Scenarios (SRES) A1B scenario using the results of a regional climate model, RegCM3, with a high horizontal resolution. First, the authors evaluate the model’s performance compared with NCEP-NCAR reanalysis data, showing that the model can reliably reproduce the basic climatology of both winter and summer monsoons over East Asia. Next, it is found that the winter monsoon in East Asia would slightly weaken in the 21st century with spatial differences. Over northern East China, anomalous southerly winds would dominate in the mid-and late-21st century because the zonal land-sea thermal contrast is expected to become smaller, due to a stronger warming trend over land than over ocean. However, the intensity of the summer monsoon in East Asia shows a statistically significant upward trend over this century because the zonal land-sea thermal contrast between East Asia and the western North Pacific would become larger, which, in turn, would lead to larger sea level pressure gradients throughout East Asia and extending to the adjacent ocean.     

A Study on Water Vapor Transport and Budget of Heavy Rain in Northeast China

The characteristics of moisture transport and budget of widespread heavy rain and local heavy rain events in Northeast China are studied using the NCEP--NCAR reanalysis 6-hourly and daily data and daily precipitation data of 200 stations in Northeast China from 1961--2005. The results demonstrate that during periods with widespread heavy rain in Northeast China, the Asian monsoon is very active and the monsoonal northward moisture transport is strengthened significantly. The widespread heavy rainfall obtains enhanced water vapor supply from large regions where the water vapor mainly originates from the Asian monsoon areas, which include the East Asian subtropical monsoon area, the South China Sea, and the southeast and southwest tropical monsoon regions. There are several branches of monsoonal moisture current converging on East China and its coastal areas, where they are strengthened and then continue northward into Northeast China. Thus, the enhanced northward monsoonal moisture transport is the key to the widespread heavy rain in Northeast China. In contrast, local heavy rainfall in Northeast China derives water vapor from limited areas, transported by the westerlies. Local evaporation also plays an important role in the water vapor supply and local recycling process of moisture. In short, the widespread heavy rains of Northeast China are mainly caused by water vapor advection brought by the Asian monsoon, whereas local heavy rainfall is mainly caused by the convergence of the westerly wind field.     

空间碎片观测中拖长星像的测光

提出空间碎片观测中对拖长背景恒星的测光算法,介绍了该方法的基本原理.利用迭代法对目标图像进行局部阈值分割提取,得到的二值图像通常包含多个连通域.最后对各连通域块检测判断,计算出目标的星等,达到测光的目的.通过与天文图像和数据处理软件IRAF的测光结果对比,此算法的误差在0.02mag左右,可以达到测光的要求.