黔西南泥堡金矿床构造特征及其控矿作用

位于扬子板块西南缘的右江盆地是我国卡林型金矿的集中分布区之一,素有滇-黔-桂"金三角"之称.泥堡金矿是右江盆地西北侧一个大型矿床,矿区构造主要有NEE向泥堡背斜、二龙抢宝背斜和同方向的F1、F3、F4、F5和F9断层,以及产于F1断层下盘的层间破碎带等.详细构造调查和新近勘查资料的综合研究表明:F1、F5和F9为逆冲断...     

基于灰色关联与模糊数学的重力式挡土墙震害评估

龙门山地区强震荷载导致大量已建边坡支挡结构严重受损,如何对震区受损挡土墙进行震害评估成为亟待解决的技术难点。本文首先通过对研究区挡土墙的震害分析,总结出其主要破坏模式包括滑移破坏、沉降破坏、倾覆破坏、墙身破坏以及越顶破坏5类。然后根据全面性、重要性以及科学性原则对影响震害评价的因子进行定性分析和分类,并结合挡墙的破坏模式,综合分析得到挡土墙安全评估的敏感性因子和一般因子。将震害范围60%作为挡墙评价的敏感性因子,而一般因子分为两级共10个指标,包括:滑移距离,沉降深度,倾斜角度,裂缝数量,裂缝长度比,开裂深度比,开裂宽度,错动距离,垮塌范围,覆盖范围。最后,采用灰色关联分析与模糊数学理论相结合的方法构建挡土墙震害评估体系,从而变事后处理为事先预防,为灾后恢复重建服务。     

A developed technique for measuring water content in oil-contaminated porous media

Water content is an important physical parameter for soil, vadose zone, and porous aquifer. Accurate measurement of water content in oil-contaminated porous media is critical for the research on oil pollution process and remediation in soil and groundwater systems. In this study, an improved water content calculation formula for oil-contaminated porous media was proposed based on the theory of oven-drying method, and laboratory experiments were conducted to test the applicability and accuracy of the formula for several types of manually prepared oil-contaminated porous media with different water contents. Furthermore, the measuring method and calculation formula, which can be used to determine the water content of porous media sampled from the oil-contaminated sites, were proposed for the first time in this study based on the improved formula. The experimental results showed that the improved formula was very accurate when used to calculate the water contents of diesel-contaminated sand, gasoline-contaminated mild clay, and engine oil-contaminated sand, indicating that it was widely applicable to oils with different volatile ability as well as porous media with different texture. This study meets the urgent need for accurate determination of water content in oil-contaminated porous media, and it solves the technical problem that the existing water content measuring methods cannot be applied directly in the field study.     

On the calculation of spurious velocity signal produced by atmospheric differential extinction in whole-disk oscillation measurements

The systematic diurnal signal drift in full-disk solar oscillation measurements has been calculated taking into account differential rotation, the inclination of the rotational axis of the Sun with respect to the picture plane, the limb-darkening function and a realistic estimation of the sky transparency, slightly variable during the day. An illustration of this method on the Kumbel (U.S.S.R.) IRIS data is presented and discussed.     

Models of neutron stars in generalized bimetric theory of gravitation

Yerevan State University; Institute of Applied Physics Problems, Armenian Academy of Sciences. Translated fromAstrofizika, Vol. 35, No. 1, pp. 121–129, July–August, 1991.     

New Criterion for Lunar Crescent Visibility

A new criterion for lunar crescent visibility has been established using 737 observations, almost half of them obtained by the Islamic Crescent Observation Project (ICOP). This criterion is based on two variables, viz. the topocentric arc of vision and the topocentric crescent width. The new model is able to predict the visibility of the lunar crescent both for naked eye and optically aided observations. From the database we found a Danjon limit of 6.4 degrees. Vice-President of “Crescents, Calendars and Mawaqeet Committee” of AUASS.     

区域地下水污染综合评价研究现状与建议

区域地下水污染综合评价研究是一项总结区域地下水水质特征、评估地下水水质和污染状况、分析其驱动机制、研判其演化趋势的重要基础性工作,也是地下水污染防控以及水质改善的重要依据。受水文地质领域一些传统概念、观念以及技术方法的限制,在水质综合评价、污染评价、天然劣质水与污染的区分、人类活动影响等方面存在诸多问题和挑战,认知的科学性和可靠性不断受到质疑,给政府管理部门的应用和决策带来困惑。本研究通过梳理分析近年来区域地下水污染综合评价的研究现状,回顾总结了在水质综合评价、背景值、污染评价、劣质水和劣变水评估以及人类活动识别等方面存在的问题,提出了几点认识和建议:(1)“指标分类评价-组合表达”的水质及污染综合评价思路,可为解决现阶段水质及污染综合评估容易造成歧义和误导的问题提供新的方向;(2)视背景值的建立不仅能够解决传统概念背景值无法获取的问题,还能有效进行污染判定、劣质水和劣变水评估以及人类活动识别,是一项亟待全面开展的基础性工作;(3)劣质水和劣变水概念及评价思路的提出,对区分天然劣质水和污染水具有借鉴意义,在科学回答这两类水对我国地下水水质的影响、帮助决策者理解水质不安全成因等方面有重要意义,但是方法学方面需要进一步探讨;(4)对人类活动影响的识别和量化,进一步推动了对输入型污染、诱导型水质恶化以及水化学场变化所引起的各种水质问题的认识,进而对判断水质演化趋势、污染防控、分类解决水质问题具有重要的意义。     

江西武功山中生代花岗岩的锆石U-Pb年龄、Hf同位素特征及其地质意义

江西省武功山地区主要发育早古生代和中生代两期花岗岩,后者主要为二云二长花岗岩和黑云母二长花岗岩等,分布于三江村、明月山及和平村等地区, 为了研究其形成时代、岩石成因、源区特征和构造环境,分别选取三江地区和和平地区的细中粒斑状黑云母二长花岗岩及细粒斑状二云二长花岗岩进行岩石学、矿物学、地球化学、锆石U-Pb同位素测年和锆石Lu—Hf同位素研究。花岗岩SiO2含量为72.96%~74.16%,Na2O+K2O含量为6.68%~8.42%,MgO含量为029%~0.70%,铝饱和指数A/CNK为1.11~1.36,为强过铝质高钾钙碱性花岗岩。ΣREE较低,稀土配分曲线呈右倾型,具强烈δEu负异常,为S型花岗岩。花岗岩锆石n（206Pb）/n（238U）年龄加权平均值为152.41±0.89 Ma和149.31±0.71 Ma,为晚侏罗世岩浆活动的产物。花岗岩 fLu/Hf值均小于-0.9,εHf（t）均为负值,岩浆来源于演化的元古宙陆壳物质。地质演化背景结合样品构造判别图解,综合分析认为武功山中生代花岗岩形成于陆内俯冲环境。