全文获取类型
收费全文 | 254篇 |
免费 | 7篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 17篇 |
大气科学 | 33篇 |
地球物理 | 49篇 |
地质学 | 85篇 |
海洋学 | 4篇 |
天文学 | 68篇 |
综合类 | 3篇 |
自然地理 | 6篇 |
出版年
2022年 | 6篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 16篇 |
2015年 | 9篇 |
2014年 | 17篇 |
2013年 | 20篇 |
2012年 | 10篇 |
2011年 | 18篇 |
2010年 | 7篇 |
2009年 | 16篇 |
2008年 | 8篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有265条查询结果,搜索用时 15 毫秒
61.
Natural Hazards - This study uses a high-resolution Weather Research and Forecasting model coupled with the chemistry module (WRF-Chem) to analyze the dust storm that occurred during 12?17... 相似文献
62.
Suchandra Aich Bhowmick Rashmi Sharma K. N. Babu A. K. Shukla Raj Kumar R. Venkatesan 《Marine Geodesy》2015,38(3):193-205
The focus of this study is the validation of significant wave height (SWH) and sea surface height anomaly (SSHA) obtained from the first Ka-band altimeter AltiKa onboard SARAL (Satellite for ARGOS and Altimeters). It is a collaborative mission of the Indian Space Research Organization and Centre National d'Etudes Spatiales (CNES). This is done using in-situ observations from buoy and Jason-2 measurements. Validation using buoy observations are at particular locations while that using Jason-2 altimeter is an attempt towards global validation of Altika products. The results clearly indicate that the SARAL/AltiKa provide high-quality data and the errors are within a predefined range of accuracy. A parallel validation of SWH from other altimeters, which monitored ocean since last decade, like EnviSAT and Jason-2 was also performed with buoy observations. The results clearly show that the accuracy of AltiKa SWH is much better than EnviSAT and comparable to reference mission Jason-2. The accuracy is quite good for the calm sea while in the rough seas the accuracy degrades some. The inter-comparison of SARAL/AltiKa SSHA with Jason-2 indicates a fair match between them. These validation exercises demonstrate the high quality of AltiKa products, usable for practical applications. 相似文献
63.
64.
Purushottam Kumar Garg Jairam Singh Yadav Santosh Kumar Rai Aparna Shukla 《地学前缘(英文版)》2022,(1):255-267
Glaciological mass balance(MB)is considered the most direct,undelayed and unfiltered response of the glaciers to climatic perturbations.However,it may inherit errors associated with stake underrepresentation,averaging over the entire glacier and human bias.Therefore,proper validation of glaciological MB with geodetic MB is highly recommended by the World Glacier Monitoring Service(WGMS).The present study focuses on the Dokriani Glacier,central Himalaya which is one of the bench-mark glaciers in the region and has glaciological MB records from 1993 to 2013 with intermittent gaps.In the present study,firstly the glaciological MB series is extended to 2014 i.e.,field-based MB for one more year is computed and,to compare with it,the geodetic MB is computed for the 1999–2014 period using high resolution Cartosat-1 digital elevation model(DEM)and SRTM DEM.Finally,the study assesses the regional representation of the Dokriani Glacier in terms of MB and evaluates the influence of the MB regime on its morphological evolution.Results show that the average glaciological MB(-0.34±0.2 m water equivalent(w.e.)y-1)is more negative than the geodetic MB(-0.23±0.1 m w.e.y-1)for the 1999–2014 period.This is likely because of the partial representation of glacier margins in the glaciological MB,where melting is strikingly low owing to thick debris cover(>30 cm).In contrast,geodetic MB considers all marginal pixels leading to a comparatively low MB.A comparative assessment shows that the MB of Dokriani Glacier is less negative(possibly due to its huge accumulation area)than most other glacier-specific and regional MBs,restricting it to be a representative glacier in the region.Moreover,continuous negative MB has brought a peculiar change in the epiglacial morphology in the lower tongue of the glacier as differential debris thickness-induced differential melting has turned the glacier surface into a concave one.This concavity has led to development of a large(10–20 m deep)supraglacial channel which is expanding incessantly.The supraglacial channel is also connected with the snout wall and accelerates terminus disintegration.Given the total thickness of about 30–50 m in the lower glacier tongue,downwasting at its current pace,deepening/widening of supraglacial channel coupled with rapid terminus retreat may lead to the complete vanishing of the lower one km glacier tongue. 相似文献
65.
R. C. Bhandari L. F. Curtis U. C. Shukla 《Journal of the Indian Society of Remote Sensing》1976,4(1-2):37-41
LANDSAT-MSS data in the form of a false colour composite image at a scale of 1:250,000 has been used to produce terrain unit maps of parts of north west India. The area of study consisted of central and southern districts of Haryana State. It has been possible to obtain a qualitative assessment of land use patterns and surface hydrology by means of visual Interpretation. The boundaries between differeat terrain units and moisture regimes were clearly discernible It is felt that comparative studies of false colour infrared imagery over a period of time can provide valuable Information for those engaged in reclamation schemes. In particular, the data can be used to plan reclamation of salt affected and waterlogged lands in semi-arid zones of states like Haryana. 相似文献
66.
67.
In the present work, histological changes in the gill, liver, kidney and intestine of Notopterus notopterus, induced by pulp waste, paper waste and mixed pulp and paper waste, have been studied both at sublethal and lethal concentrations. The pulp waste produces much more histological changes both at sublethal and lethal concentrations in the gill, liver, kidney and intestine as compared to paper waste and mixed pulp and paper waste. The changes are much more remarkable in the case of sublethal concentration, as compared to a lethal concentration. In a sublethal concentration, the localized necrosis, atrophy and partial and total liquefaction of epithelial cells, pilaster cells, mucous cells of the gill, hepatic cells of the liver, mesenchymatous cells, renal tubule cells and Bowman's capsule of the kidney, mucosal and submucosal cells and blood vessels of intestine have been observed. In lethal concentration, the changes are much more marked in the gill, as compared to the liver, kidney and intestine. The histological changes, produced in the different types of cells and in the tissue as a whole, can be correlated with the different chemical components present in the pulp waste, paper waste and mixed pulp and paper waste. 相似文献
68.
P. N. Shukla N. Bhandari V. N. Nijampurkar D. Kameswara Rao V. M. K. Puri Sanjiv Sharma 《Journal of Earth System Science》1983,92(3):255-260
Vertical profiles of137Cs and210Pb have been determined in a 9 m column of ice from accumulation zone of Changme-Khangpu glacier in north Sikkim valley.137Cs activity varies from 4 to 22 dpm/ L. In many samples210Pb occurs at a level of 20 to 65 dpm/ L which is much higher than the expected fallout value.137Cs and210Pb activities correlate well with each other but not with the dust content. Possibility of210Pb production in the nuclear explosions is discussed. Several peaks appear in the depth profile of137Cs and210Pb which can be matched with Chinese atmospheric nuclear explosions with some phase difference if a uniform ice accumulation
rate of 0.7 m per year is assumed since 1969. 相似文献
69.
70.
It is shown that dust-neutral and ion-neutral drags can produce instabilities of electrostatic waves in multicomponent self-gravitating dusty plasmas. Explicit expressions for the growth rates of the instabilities are presented. The relevance of our investigation to fragmentation of molecular dust clouds is discussed. 相似文献