边坡稳定性评价的模糊层次分析方法

针对常用边坡稳定性分析方法的复杂性和局限性,将层次分析法和模糊数学理论结合起来,建立了边坡稳定性评价的模糊层次分析模型,同时应用该评价模型对清江隔河岩水电站厂房高边坡进行了分析评价。结果表明,使用该模型可以使边坡稳定性评价更全面、更科学、更符合实际,该方法简便可行,结论可靠,具有一定的优越性,为决策者提供了有力的参考和支持。     

Parameterisation of surface radiation flux at an Antarctic site

During the Antarctic summer 1994/95 the values of downward and upward flux densities of both solar and terrestrial radiation were recorded at 1200 m for a period of 1 month on the Reeves Nevè Glacier (lat 74°39′S, long 161°35′E), near the Italian base of Terra Nova Bay. The relations proposed by Swinbank [Swinbank, W.C., 1963. Long-wave radiation from clear skies. Q. J. R. Meteorol. Soc. 89, 339–348], Idso and Jackson [Idso, S.B., Jackson, R.D., 1969. Thermal radiation from the atmosphere. J. Geophys. Res. 74, 5397–5403] and Deacon [Deacon, E.L., 1970. The derivation of Swinbank's long-wave radiation formula. Q. J. R. Meteorol. Soc. 96, 313–319] associating the long-wave atmospheric radiation flux only to the air temperature at screen level were tested in extreme Antarctic climatological condition. A relation between the long-wave radiation flux and both screen air temperature and cloud cover fraction in accordance to the height of the cloud base was defined using the Kasten and Czeplak relationship that relates the solar radiation flux and the cloud cover index. The study of the incoming short-wave radiation flux from the clear sky and that reflected by the surrounding snow cover allowed for highlighting the role of surface geometry on the albedo measurements.     

Cloud drop spectra at different levels and with respect to cloud thickness and rain

Measurements on drop size were made in cumulus clouds over Pune (inland region) during the summer monsoon seasons. In this paper, the measurements of the cloud drop spectra made in non-raining clouds at different levels and for different thickness have been studied. Also, those on the days with rain and with no rain (the rain being observed within the clouds) have been compared. The average spectra broadened with height. The concentration of drops >50 μm (N_L), liquid water content (LWC), mean volume diameter (MVD) and dispersion increased with height. The concentration of drops <20 μm (N_S) and total concentration (N_T) decreased with height. The spectra were broader, while N_S and N_T are smaller and the other parameters are greater for thicker clouds as compared to those for thinner. The spectra were broader, while N_S and N_T are smaller and the other parameters are greater on the days with rain with respect to those on the days with no rain. The distributions were bimodal at higher levels, for thicker clouds and on the days with rain, while they were unimodal at lower levels, for thinner clouds and on the days with no rain. The variations of the cloud drop spectra, preceding rain, at initial stage of rain and following rain are discussed.     

喷锚支护技术在昆明市深基坑工程中的应用

喷锚支护已在昆明市深基坑工程中得到广泛的应用 ,本文简述喷锚支护基本原理和施工工艺 ,并针对昆明市区地层特点 ,介绍近期所采用的相应施工措施。     

基于可执行对象模型的通信系统软件开发过程

讨论了使用可执行对象模型开发通信系统的相关概念、方法和技术 ,提出了一个利用可执行对象模型进行通信系统开发的过程 ,以提高通信软件质量 ,缩短开发周期 ,减少软件维护费用     

松辽盆地徐家围子断陷深层天然气同位素倒转现象研究

天然气的同位素组成受源岩有机质类型、热演化程度和成藏后的次生变化等多种因素的影响, 其单体烃同位素分布特征是区分各种因素影响程度的地球化学指纹.天然气单体烃同位素通常有随碳数增加而变重的趋势, 而徐家围子深层天然气单体烃同位素倒转现象却比较普遍, 高地温和细菌氧化对于造成该区同位素倒转的可能性不大, 浅层油型气或无机气的混合作用没有充分的地质证据, 同层有机质中不同类型气的混合和盖层微渗漏造成的蒸发分馏作用可能是导致徐家围子断陷深层天然气同位素倒转的主要原因.      

城市建设用地与地质环境协调性评价的GIS方法及其应用

城市地质环境评价是城市规划和场地选址的基础 .以兰州市为例 ,以地理信息系统软件ARC/INFO为开发平台 ,建立了城市地质环境基础数据库 ,将城市用地类型分为高层建筑用地、多层建筑用地、低层建筑用地、垃圾填埋用地及自然保护用地 ,系统分析了各类用地与地质环境协调性评价的指标体系 ,采用层次分析法建立了评价模型 ,对不同的用地类型进行了评价 .结果表明GIS与评价模型的结合可以快捷、准确地进行城市建设用地与地质环境的协调性评价     

中国土地利用变化现代过程时空特征的研究──基于卫星遥感数据

为实现土地利用变化现代过程的卫星遥感研究,须建立时间序列完整的空间型遥感数据平台。在此基础上,通过建模分析,可以有效地研究土地利用变化的现代过程,其中包括土地利用变化的时间动态特征和空间动态特征。为探讨基于卫星遥感数据的中国土地利用变化现代过程研究的方法论,采用陆地卫星TM分层抽样方法,对全国土地利用类型区域组合、土地利用程度变化和土地利用动态度进行了分析。     

关于中国地理学发展的思考

提出了地理学发展的几点思路:①加强地球表层系统现代自然过程及其驱动力的研究,促进自然地理与人文地理的高层次综合;②加快地理科学的理论创新步伐,推动地理科学走向国际研究前沿;③充分利用现代科学技术成果,促进地理科学现代化;④高度重视野外台站科学数据积累及室内分析与模拟工作,为地理科学的发展奠定基础;⑤集中力量对重点地区进行深入研究,体现地理科学研究的区域特色;⑥充分利用现有地理科学研究成果,为社会经济建设服务。     

土性平稳随机场的空间统计特性分析

阐明了平稳随机场的空间统计特性,根据平稳随机场各态历经性概念,讨论了土层满足各态历经性的条件,以及计算空间平均方差和相关距离的公式。并结合工程实例,分析了空间平均方差计算的影响因素。