金矿床的热液流体特征研究     

王建国  孙丽娜  赵玉山  侯根群  赵纯福 《国土资源》1993,(4)

通过对中国东部金成矿区域地质特征的分析,根据氢氧同位素及流体包裹体数据特征,表明中国东部金矿床成矿流体主要来自大气降水,其次为变质作用过程释放的水和岩浆分异水;成矿金属组分主要来自太古宙变质岩系。  相似文献   

黄土斜坡稳定性的模糊信息分析法     

王家鼎  冯学才  孟兴民 《山地学报》1991,(1)

本文基于黄土斜坡稳定性的实际资料,利用信息分配、模糊一二级近似推论及信息集中等原因建立了一套黄土斜坡稳定性的评价方法。用这套方法对一些黄土斜坡(非母体)稳定性进行了验证,其结果与实际情况一致。本方法已应用于兰州市滑坡防灾规划和皋兰山三台阁北侧几个滑坡及斜坡稳定性的研究中,效果良好。  相似文献   

Shakedown in layered pavements under moving surface loads     

I. F. Collins  A. P. Wang  L. R. Saunders 《国际地质力学数值与分析法杂志》1993,17(3):165-174

Elastic–plastic deformations in pavements consisting of layers of different frictional materials are investigated. The upper bound, kinematic shakedown theorem is used to obtain estimates of the critical shakedown loads. Fully general three-dimensional deformations are considered. The influence of the loading distribution, interactions between loads, and the effect of varying the thickness, stiffness and strength of the layers are explored. Consequences of this investigation for particular existing designs of flexible pavements are investigated. In particular, it is found that the strength of the subgrade has no effect on the magnitude of the critical shakedown load.  相似文献   

激变食变星PG0027+260的CCD光变曲线     

李泳  蒋兆基  陈建生  魏名智 《中国天文和天体物理学报》1990,(2)

我们于1989年11月30日晚对PG0027+260进行了时间分辨率为108秒的高速CCD测光,得到了一条完整的光变曲线,从而确认其为激变食变星系统,轨道周期0.146~d  相似文献   

Magnetic Field Strengths and Structures from Radio Observations of Solar Active Regions     

Chang－XiZhang  G.B.Gelfreikh 《中国天文和天体物理学报》2002,2(3):266-276

Radio observations of some active regions (ARs) obtained with the Nobeyama radioheliograph at λ=1.76cm are used for estimating the magnetic field strength in the upper chromosphere, based on thermal bremsstrahlung. The results are compared with the magnetic field strength in the photosphere from observations with the Solar Magnetic Field Telescope (SMFT) at Huairou Solar Observing Station of Beijing Astronomical Observatory. The difference in the magnetic field strength between the two layers seems reasonable. The solar radio maps of active regions obtained with the Nobeyama radioheliograph, both in total intensity (I-map) and in circular polarizations (V-map), are compared with the optical magnetograms obtained with the SMFT. The comparison between the radio map in circular polarization and the longitudinal photospheric magnetogram of a plage region suggest that the radio map in circular polarization is a kind of magnetogram of the upper chromosphere. The comparison of the radio map in total intensity with the photospheric vector magnetogram of an AR shows that the radio map in total intensity gives indications of magnetic loops in the corona, thus we have a method of defining the coronal magnetic structure from the radio I-maps at λ=1.76 cm. Analysing the I-maps, we identified three components: (a) a compact bright source; (b) a narrow elongated structure connecting two main magnetic islands of opposite polarities (observed in both the optical and radio magnetograms); (c) a wide, diffuse, weak component that corresponds to a wide structure in the solar active region which shows in most cases an S or a reversed S contour, which is probably due to the differential rotation of the Sun. The last two components suggest coronal loops on different spatial scales above the neutral line of the longitudinal photospheric magnetic field.  相似文献   

Numerical prediction of blast‐induced stress wave from large‐scale underground explosion     

Chengqing Wu  Yong Lu  Hong Hao 《国际地质力学数值与分析法杂志》2004,28(1):93-109

This paper presents a numerical model for predicting the dynamic response of rock mass subjected to large‐scale underground explosion. The model is calibrated against data obtained from large‐scale field tests. The Hugoniot equation of state for rock mass is adopted to calculate the pressure as a function of mass density. A piecewise linear Drucker–Prager strength criterion including the strain rate effect is employed to model the rock mass behaviour subjected to blast loading. A double scalar damage model accounting for both the compression and tension damage is introduced to simulate the damage zone around the charge chamber caused by blast loading. The model is incorporated into Autodyn3D through its user subroutines. The numerical model is then used to predict the dynamic response of rock mass, in terms of the peak particle velocity (PPV) and peak particle acceleration (PPA) attenuation laws, the damage zone, the particle velocity time histories and their frequency contents for large‐scale underground explosion tests. The computed results are found in good agreement with the field measured data; hence, the proposed model is proven to be adequate for simulating the dynamic response of rock mass subjected to large‐scale underground explosion. Extended numerical analyses indicate that, apart from the charge loading density, the stress wave intensity is also affected, but to a lesser extent, by the charge weight and the charge chamber geometry for large‐scale underground explosions. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

测绘生产计划统计管理应用系统的建立     

宋大伟  刘英春  王佩琳 《地理信息世界》2002,(2)

基于windows软件平台及foxpro工具软件开发的“测绘生产计划统计管理应用系统 (PPCMAS)”是一种较为科学的测绘生产管理模式 ,具有较先进的技术性和通用性 ,并以多媒体方式实现信息查询和综合统计图形显示、文字说明及统计报表 ,解决了规划和管理等问题 ,提供了数据录入、资源查询、统计生成、专家系统壳、显示输出、信息通讯等多方面的功能  相似文献   

Technique for Controlling Spread of Limnotic Oncomelania   总被引：1，自引：0，他引：1  

李大美  王祥三  LAI Yonggen 《中国海洋湖沼学报》2003,21(3):251-260

Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering farming land or residential areas. This paper reports a successful design process and a new oncomelania-free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco-hydraulic behavior and detailed flow field information through CFD simulation.  相似文献   

Petrogenesis of Adakitic Intrusive Rocksin Xu-Huai Area, Eastern China     

Qinghai Wang  Wenliang Xu  Dongyan Wang  Jingqian LinCollege of Earth Sciences  Jilin University  Changchun  China 《东北亚地学研究》2003,(2)

1IntroductionAdakite has specially sense in the resuming structure background of rock formed,because of its distinctive geochemistry feature and implying partic-ular petrogenesis and ore genesis mechanism (De-fant and Drummond,1990),as a result,it arouses numerous researchers widely concern. After adakite conception was drawn by Chinese (Wang etal.,2000), it was widely concerned by domestic re-searchers (Wang etal.,2000,2001a,2001b;Xu etal.,2000;Pan etal.,2001;Qian,2001;Xu etal.,2001;X…  相似文献   

未来的国际天球参考架     

金文敬  李东明  唐正宏  王叔和 《紫金山天文台台刊》2003,(1)

本文简述了国际天球参考架的发展历史和现在射电参考架的现状—基准源选择的标准和参考架的稳定性。描述了地面上光学观测在依巴谷参考架的维持和加密的一系列工作。介绍由天体测量卫星GAIA和SIM给出的天球参考架可能逵到的精度。详述了在今后十年中地面天体测量的作用以及正在开展有关天球参考架的研究课题 ,同时也列出了我国正在和即将开展天体测量的几个研究课题  相似文献