全文获取类型
收费全文 | 416篇 |
免费 | 7篇 |
国内免费 | 14篇 |
专业分类
测绘学 | 24篇 |
大气科学 | 26篇 |
地球物理 | 65篇 |
地质学 | 214篇 |
海洋学 | 21篇 |
天文学 | 56篇 |
综合类 | 16篇 |
自然地理 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 7篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 30篇 |
2017年 | 33篇 |
2016年 | 30篇 |
2015年 | 30篇 |
2014年 | 32篇 |
2013年 | 42篇 |
2012年 | 20篇 |
2011年 | 13篇 |
2010年 | 17篇 |
2009年 | 11篇 |
2008年 | 18篇 |
2007年 | 10篇 |
2006年 | 11篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 8篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有437条查询结果,搜索用时 15 毫秒
431.
Helga de Wall Stefan Schöbel Manoj K. Pandit Kamal K. Sharma J. Just 《Journal of the Geological Society of India》2010,75(1):239-253
The Mirpur granite body represents a relatively small (10 km2) pluton intruded along the northern margin of the adjacent Mt. Abu batholith (∼125 km2) in NW India. It is a visibly undeformed alkali feldspar rich pink granite; in contrast, the Mt. Abu is a composite granitoid
body and variably deformed. Both are intruded by rhyolitic dykes and the terminal magmatic events in both the cases are mafic
dykes. The AMS (Anisotropy of Magnetic Susceptibility) data identify the Mt. Abu with SE-dipping foliations and subvertical
lineations as a single structural domain while the Mirpur granite body shows two domains characterized by predominantly E
— W trend of magnetic foliation in the eastern part (domain I) and N — S orientations in the western part (domain II). The
domain I shows magmatic fabrics, typical for the peraluminous granites of Malani Igneous Suite (MIS). Change in fabric orientation
in the domain II has resulted from cataclasis wherein the samples show destruction of the original E — W fabric and complete
transposition by N — S trends. The foliations in the Mt. Abu granites have been related to SE orientation of maximum horizontal
stress. The same maximum stress direction can be inferred from dyke orientation in the Mirpur granite, which is interpreted
as continuation of the tectonic imprint in this region during emplacement of both the granites. Age of the cataclastic overprint
with a predominant N — S orientation is not yet constrained but corresponds with the trend of the nearby Sindreth basin within
the Malani Igneous Suite. The Neoproterozoic tectonic scenario for the region has been interpreted in terms of an ongoing
crustal convergence and granitic magma emplacement against the back stop offered by the rigid Delhi Fold Belt. 相似文献
432.
Drinking and irrigational feasibility of groundwater,GIS spatial mapping in upper Thirumanimuthar sub-basin,Cauvery River,Tamil Nadu 总被引:1,自引:0,他引:1
M. Suresh B. Gurugnanam S. Vasudevan K. Dharanirajan N. Jawahar Raj 《Journal of the Geological Society of India》2010,75(3):518-526
In the present study, the chemical characteristics of groundwater with respect to drinking and Irrigation water quality in
upper Thirumanimuthar sub-basin, Cauvery River, have been studied. 51 groundwater samples were collected and analysed for
pH, conductance, total dissolved solids, total hardness, calcium, magnesium, carbonate, bicarbonate, total alkalinity, chloride,
sodium, potassium, sulphate etc. The values analyzed were evaluated in detail and compared with WHO water quality standards.
It is observed that, for most of the groundwater quality parameters, the values are not potable for drinking and irrigational
use. To understand the spatial distribution of unsuitable zones, ArcGIS was employed. Attributes were linked and spatial interpolation
mapping was done. Inverse distance weighted interpolation technique was followed for raster and vector mapping. Finally the
overlay analyses were also carried out to locate the worst quality zone. 相似文献
433.
Numerical model and flume experiments of single- and two-layered hillslope flow related to slope failure 总被引:1,自引:0,他引:1
A hillslope flow model is developed considering 3D saturated and unsaturated flow of water during rainfall events. A finite difference-based numerical model of hillslope flow processes is developed. Four different experiments are done to see the effects of a single- and double-layered soil in pore-water pressure dynamics and slope failure. Results from the numerical model are verified with experimental results. The numerical and experimental values of the pore-water pressure and moisture contents are in good agreement. The results show that the hillslope heterogeneity caused by multiple layers of soil has greater influence on hillslope pore-pressure dynamics and slope failure patterns. The depth of slope failure shows high dependency on layering characteristics of the soil slope and pattern of rainfall. The proposed model provides a perspective on failure mechanism of a single- or double-layered slope under rainfall infiltration. 相似文献
434.
435.
Numerical simulation of a typical tropical thunder storm event at Pune (18.53°N, 73.85°E), India, has been performed using the three nested domain configuration of Weather Research and Forecasting-Advanced Research Weather Model (version 3.2). The model simulations have been compared with observations. Sensitivity to cumulus parameterization schemes, namely Betts–Miller (BM), Grell–Devenyi (GD), and Kain–Fritsch (KF), for simulation of vertical structure and time evolution of weather parameters has been evaluated using observations from automatic weather station and global positioning system radiosonde ascents. Comparison of spatial distribution of 24-h accumulated rain with Tropical Rainfall Measuring Mission data shows that BM scheme could simulate better rain than GD and KF schemes. The BM scheme could well simulate the development of storm and heavy rain as it could generate sufficiently humid and deep layer in the lower and middle atmosphere, along with co-existence of updrafts and downdrafts and frozen hydrometeors at the middle level and rain water near the surface. 相似文献
436.
V.N. Viswanathan D.V. Ramana Rao Kamal Kumar 《International Journal of Mineral Processing》1980,7(2):137-146
Whereas high-grade dolomites and limestones find extensive use in the refractory and steel industries, high-silica dolomitic limestones are of little use and can cause disposal problems as mining rejects. The removal of silica and magnesia to certain specified limits can make them suitable for cement manufacture. Magnesia can be removed by a carbonation process after semi-calcination of dolomite but the removal of a large amount of silica prior to MgO separation, by the flotation process alone, is uneconomical. Here the results are presented of the investigations of hydrocyclone separation of silica from one such type of mining rejects. The results show that after grinding the feed material to suitable levels of liberation of quartz and carbonate grains, two cycles of operation in a 4′′ hydrocyclone, can recover about 45% of the limestone feed material with a lime/silica ratio adequate for cement manufacture. 相似文献
437.
In this paper, we developed statistical method for distance determination of a stellar group. The method depends on the assumption that, the stars scatter around a mean magnitude in a Gaussian distribution. The mean apparent magnitude of the stars is then expressed in terms of the frequency function of the apparent magnitudes, so as to correct for observational incompleteness at the faint end. The problem reduces to the solution of a highly transcendental equation for a given apparent magnitude parameter α. Computational algorithm of the method is illustrated and the numerical solutions of the basic equation are given for some values of α . 相似文献