东北三省城市扩展及植被覆盖状况

基于三期遥感影像数据( MSS、ETM、CBERS) 对城市建成区的面积进行了调查,研究30 多年来东北三省城市的扩展情况,并且结合NDVI 数据,对研究区范围内的植被覆盖情况进行了研究。结果表明: 1976-2000 年、2000-2007 年两个阶段,城市建成区的面积持续增加,年均扩展率由 5. 10%增加至6. 32%,扩展强度比较显著的区域主要分布在哈大交通经济带上; 研究区范围内东部的植被覆盖情况明显好于西部,NDVI 均值随与城市距离的增加而提高。     

浅析云峰井变径前后气压效应与井径比的关系

本文通过改变云峰井孔径试验,探讨了提高地下水观测井映震能力的一种途径。     

The onset of chaotic motion in the restricted problem of three bodies

A full characterization of a nonintegrable dynamical system requires an investigation into the chaotic properties of that system. One such system, the restricted problem of three bodies, has been studied for over two centuries, yet few studies have examined the chaotic nature of some ot its trajectories. This paper examines and classifies the onset of chaotic motion in the restricted three-body problem through the use of Poincaré surfaces of section, Liapunov characteristic numbers, power spectral density analysis and a newly developed technique called numerical irreversibility. The chaotic motion is found to be intermittent and becomes first evident when the Jacobian constant is slightly higher thanC ₂.     

裂隙岩质边坡地下水渗流数值模拟

本文从反倾向岩质高边坡的渗流特征和渗流普遍规律出发,根据渗流力学知识,建立数学模型,通过渗流数值模拟计算分析了渗透压力、水头变化规律以及对岩质边坡稳定性的影响.     

高应变法在判定大直径灌注桩缺陷中的应用

测试数据准确可靠的高应变法检测,能够定量分析基桩缺陷,准确判定缺陷位置。通过工程桩的低应变法和高应变法对桩身完整性判定分析的工程实例,结合钻芯法验证,总结高应变法在不同情况下对桩身完整性的评定。     

Momentum transport of wave zero during March: A possible predictor for the Indian summer monsoon

Analysis of monthly momentum transport of zonal waves at 850 hPa for the period 1979 to 1993, between ‡S and ‡N for January to April, using zonal (u) and meridional (v) components of wind taken from the ECMWF reanalysis field, shows a positive correlation (.1% level of significance) between the Indian summer monsoon rainfall (June through September) and the momentum transport of wave zero TM(0) over latitudinal belt between 25‡S and 5‡N (LB) during March. Northward (Southward) TM(0) observed in March over LB subsequently leads to a good (drought) monsoon season over India which is found to be true even when the year is marked with the El-Nino event. Similarly a strong westerly zone in the Indian Ocean during March, indicates a good monsoon season for the country, even if the year is marked with El-Nino. The study thus suggests two predictors, TM(0) over LB and the strength of westerly zone in the Indian Ocean during March.     

岩体工程质量分级应用研究

岩体质量评价采用的测试技术包括地质勘察、弹性波检测和室内岩石力学试验。结合水布垭水利枢纽大坝建基岩体工程质量评价实例,对岩体工程质量分级的应用进行了研究。     

双坡面临空岩质边坡滑动破坏模式下的稳定性分析

多数岩质边坡稳定性分析已基本解决了常走向单坡面临空的边坡平面滑动问题。然而,在路堑边坡工程和自然边坡中有很多边坡坡面并不是平面,它包含多个坡面。多坡面边坡包含两个或多个不同走向的坡面。多坡面边坡几何特征不同于单坡面边坡,所以滑动条件也不一样。在赤平投影图上,多坡面的滑动包络线是组成边坡的每个坡面单独投影包络线的组合。为了探讨方便,只讨论了双坡面临空岩质边坡的滑动破坏模式,并将其分为双坡面临空下的平面破坏和楔形体破坏。在赤平投影图上,双坡面滑动区域定义为双坡面边坡滑动包络图中两侧坡面的真倾线之间的面积。如果有一两个节理面真倾向线落在滑动区内,滑动破坏才可能发生。     

浅谈全国第二次土地调查项目的几个关键环节

介绍了全国第二次土地调查项目中调绘底图生产、土地调查、田坎系数测定、农村宅基地调查等关键环节,结合实际生产,分析了各环节的重要性及实施情况。     

Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China

To study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the Permian Period from the Huainan coalfield, Anhui province, China, borehole samples of 336 coals, two partings, and four roof and floor mudstones were collected from mineable coal seams. Major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HAAS). The depositional environment, abundances, distribution, and modes of occurrence of trace elements were investigated. Results show that clay and carbonate minerals are the principal inorganic constituents in the coals. A lower deltaic plain, where fluvial channel systems developed successively, was the likely depositional environment of the Permian coals in the Huainan coalfield. All major elements have wider variation ranges than those of Chinese coals except for Mg and Fe. The contents of Cr, Co, Ni, and Se are higher than their averages for Chinese coals and world coals. Vertical variations of trace elements in different formations are not significant except for B and Ba. Certain roof and partings are distinctly higher in trace elements than underlying coal bench samples. The modes of occurrence of trace elements vary in different coal seams as a result of different coal-forming environments. Vanadium, Cr, and Th are associated with aluminosilicate minerals, Ba with carbonate minerals, and Cu, Zn, As, Se, and Pb mainly with sulfide minerals.