全文获取类型
收费全文 | 359篇 |
免费 | 3篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 23篇 |
大气科学 | 13篇 |
地球物理 | 52篇 |
地质学 | 128篇 |
海洋学 | 15篇 |
天文学 | 121篇 |
综合类 | 5篇 |
自然地理 | 9篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 23篇 |
2017年 | 24篇 |
2016年 | 16篇 |
2015年 | 4篇 |
2014年 | 20篇 |
2013年 | 34篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 18篇 |
2009年 | 26篇 |
2008年 | 19篇 |
2007年 | 8篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 8篇 |
1986年 | 8篇 |
1985年 | 1篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有366条查询结果,搜索用时 171 毫秒
21.
Interactive visualization has been an integral part of landscape simulation to facilitate understanding of environmental processes.
In most cases, however, interaction with the data is limited to viewing only. Thus to support more 3D interaction, in this
study an attempt has been made to apply multi-view approach of the model for orientation, navigation and selection as visual
metaphors on the landscape. This paper further describes how JAVA 3D/VRML can be used to model a landscape for better user
interaction and exploration. Data used for generation of landscape model is SRTM-3 pertaining to a part of Alwar district
in Rajasthan. This study emphasizes the importance of user interaction with 3D landscape for visualizing future design implications,
landuse change and visual exploration. 相似文献
22.
23.
The various forms of energy and energy conversions have been computed over a part of the Indian region during an active monsoon period, using the quasigeostrophic baroclinic model. The energetics of the monsoon depression have been discussed on the basis of these results. 相似文献
24.
Protein digestibility was determined via two feeding trials in glass aquaria by the indicator (Chromium oxide) method using a mixture of shrimp powder with oil cake and wheat bran respectively (1: 1 W/W) as food. Analyses of feed were made to calculate the crude protein, carbohydrate, lipid and ash contents. Feces were analysed to determine their total nitrogen and chromium oxide. Protein digestibility was studied in relation to salinity of the medium size and weight of the fish body. The apparent digestibility of crude protein of a corresponding die has shown that 1st: Younger fish do possess a lower capability of protein digestion than fish having a medium weight and medium size; 2nd: Older fish with a high weight and large size exhibit no improvement in efficiency to digest the food protein, though their weight and size are significantly greater than those of middle weight and medium size fish; 3rd: The replacement of oil cake by wheat bran decreases the protein digestibility of shrimp powder mixture with them; 4th: A salinity (NaCl) of the aquatic medium at or above 3 g/l depletes the protein digestibility when fish of the same size were experimented with; but a salinity up to 2 g/l does not result in a significant decrease in the protein digestion rate. 相似文献
25.
K. N. Chari N. C. Pandey G. Mahapatra C. Patro 《Journal of the Indian Society of Remote Sensing》1978,6(2):57-62
In order to prepare schemes for Land reclamation, plantation and permanent settlement of the tribals of shifting cutivation areas in Orrisa a proper survey is a prerequisite. Earlier attempts vaguely idenified these areas. Wide disparity in data are found in the reports from different sources. Interpretation of LANDSAT-1 imagery can be used to study shifting cultivation areas in a scientific way. Lack of forests on sloping land is the chief characteristic of shifting cullivation areas. Landsat observation along with classified slope from topographic sheets provide most reliable and accurate data by minimising human error. 相似文献
26.
G. S. Dubey U. S. Pandey J. P. Singh L. K. Singh S. N. Singh 《Journal of Astrophysics and Astronomy》1990,11(1):23-28
The equation governing the equilibrium of a centrally-symmetric, self-gravitating distribution of matter is obtained by assuming
that matter is described by magnetofluid and it is shown that the equation of stellar structure described by an ideal fluid
is recovered when magnetic fieldh is vanishing 相似文献
27.
Neeraj Singh Bankoti Navin Chandra Joshi Bimal Pande Seema Pande Wahab Uddin Kavita Pandey 《New Astronomy》2011,16(4):269-275
This paper presents the study of normalized north–south asymmetry, cumulative normalized north–south asymmetry and cumulative difference indices of sunspot areas, solar active prominences (at total, low (?40°) and high (?50°) latitudes) and Hα solar flares from 1964 to 2008 spanning the solar cycles 20–23. Three different statistical methods are used to obtain the asymmetric behavior of different solar activity features. Hemispherical distribution of activity features shows the dominance of activities in northern hemisphere for solar cycle 20 and in southern hemisphere for solar cycles 21–23 excluding solar active prominences at high latitudes. Cumulative difference index of solar activity features in each solar cycle is observed at the maximum of the respective solar cycle suggesting a cyclic behavior of approximately one solar cycle length. Asymmetric behavior of all activity features except solar active prominences at high latitudes hints at the long term periodic trend of eight solar cycles. North–south asymmetries of SAP (H) express the specific behavior of solar activity at high solar latitudes and its behavior in long-time scale is distinctly opposite to those of other activity features. Our results show that in most cases the asymmetry is statistically highly significant meaning thereby that the asymmetries are real features in the N–S distribution of solar activity features. 相似文献
28.
Anshu Prakash Mishra A. C. Pandey S. Rai 《Journal of the Geological Society of India》2010,76(5):468-478
In this article, the authors examine Sea surface temperature (SST), Sea surface circulation (SSC) and Vertical velocity (VV) fields from simulation of 25 layers coarse resolution Modular ocean model (MOM version 3.0) with prescribed wind forcing for the region 74.25°S to 65°N, 180°W-180°E. It is found that distribution of SST simulated by the model shows its consistency with the observed climatology. However, simulated SST in the areas of Arabian Sea, Bay of Bengal, Indonesian Throughflow (ITF) region and east of North America near equator exhibit slight warming with respect to observation, which may be due to model deficiency and forcing problems. Circulation features suggest that one of the strongest current viz. Antarctic circumpolar current (ACC) along with other major current systems viz. Gulf stream current, North and South Pacific current, Agulhas current, Labrador current, Canary current, etc are captured well by the model. In the Indian Ocean and other ocean basins, current patterns are well captured by the model simulation. Intense upwelling as well as downwelling areas is marked in the horizontal distribution of VV, which is as expected. VV show quasi-stagnant and convergent regions suggesting that floating materials may be accumulated during January/July in the real ocean and wind driven circulation may act as an important contribution for such transport of floating materials in these regions. An attempt has also been made to understand the fluctuations of the SST in NINO 3.4 region during the period of model simulation using SST anomalies. 相似文献
29.
Md. M. Rahman Z.-H. Shon C.-J. Ma R. J. C. Brown S. K. Pandey C. G. Park I. S. Bae J. R. Sohn H.-O. Yoon K.-H. Kim 《International Journal of Environmental Science and Technology》2014,11(7):1897-1910
In this work, 17-polychlorinated dibenzo-p-dioxin/furan (PCDD/Fs) isomers were measured in ambient air at four urban sites in Seoul, Korea (from February to June 2009). The concentrations of their summed values (ΣPCDD/Fs) across all four sites ranged from 1,947 (271 WHO05 TEQ) (Jong Ro) to 2,600 (349 WHO05 TEQ) fg/m3 (Yang Jae) with a mean of 2,125 (± 317) fg/m3 (292 WHO05 TEQ fg/m3). The sum values for the two isomer groups of ΣPCDD and ΣPCDF were 527 (30 WHO05 TEQ) and 1,598 (263 WHO05 TEQ) fg/m3, respectively. The concentration profile of individual species was dominated by the 2,3,4,7,8-PeCDF isomer, which contributed approximately 36 % of the ΣPCDD/Fs value. The observed temporal trends in PCDD/F concentrations were characterized by relative enhancement in the winter and spring. The relative contribution of different sources, when assessed by principal component analysis, is explained by the dominance of vehicular emissions along with coal (or gas) burning as the key source of ambient PCDD/Fs in the residential areas studied. 相似文献
30.
Hypsometric analysis of Shakkar river catchment through geographical information system 总被引:2,自引:0,他引:2
Sarita Gajbhiye S. K. Mishra Ashish Pandey 《Journal of the Geological Society of India》2014,84(2):192-196
Hypsometric analysis of watershed (area-elevation analysis) has generally been used to reveal the stages of geomorphic development (stabilized, mature and young). The geologic stages of development and proneness of the watersheds for erosion are quantified by hypsometric integral. The estimation of hypsometric integral is carried out from the graphical plot of the measured contour elevation and encompassed area by using empirical formulae. In this study, efforts were made to estimate the hypsometric integral values of Shakkar river watershed which is a tributary of Narmada river located in Madhya Pradesh. The watershed was delineated into eight sub-watersheds and hypsometric analysis was carried out for all of them using digital contour maps, which was generated using Arc/Info GIS. The hypsometric integral values for all the sub-watersheds of Shakkar river ranges between 0.47 and 0.51. In the study area, only mature stage of erosion cycle is identified. 相似文献