全文获取类型
收费全文 | 187篇 |
免费 | 4篇 |
专业分类
测绘学 | 22篇 |
大气科学 | 5篇 |
地球物理 | 52篇 |
地质学 | 74篇 |
海洋学 | 11篇 |
天文学 | 22篇 |
自然地理 | 5篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 9篇 |
2017年 | 17篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 11篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 6篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有191条查询结果,搜索用时 15 毫秒
101.
K Narasimha Murty Nittala S Sarma Sudarsana Rao Pandi Gundala Chiranjeevulu Rayaprolu Kiran R Muralikrishna 《Journal of Earth System Science》2017,126(6):82
The influence of hydrodynamics on phytoplankton bloom occurrence/formation has not been adequately reported. Here, we document diurnal observations in the tropical Bay of Bengal’s mid-western shelf region which reveal microphytoplankton cell density maxima in association with neap tide many times more than what could be accounted for by solar insolation and nutrient levels. When in summer, phytoplankton cells were abundant and the cell density of Guinardia delicatula reached critical value by tide caused zonation, aggregation happened to an intense bloom. Mucilaginous exudates from the alga due to heat and silicate stress likely promoted and stable water column and weak winds left undisturbed, the transient bloom. The phytoplankton aggregates have implication as food resource in the benthic region implying higher fishery potential, in carbon dioxide sequestration (carbon burial) and in efforts towards improving remote sensing algorithms for chlorophyll in the coastal region. 相似文献
102.
Pramit Kumar Deb Burman Dipankar Sarma Mathew Williams Anandakumar Karipot Supriyo Chakraborty 《Journal of Earth System Science》2017,126(7):99
Tropical forests act as a major sink of atmospheric carbon dioxide, and store large amounts of carbon in biomass. India is a tropical country with regions of dense vegetation and high biodiversity. However due to the paucity of observations, the carbon sequestration potential of these forests could not be assessed in detail so far. To address this gap, several flux towers were erected over different ecosystems in India by Indian Institute of Tropical Meteorology as part of the MetFlux India project funded by MoES (Ministry of Earth Sciences, Government of India). A 50 m tall tower was set up over a semi-evergreen moist deciduous forest named Kaziranga National Park in north-eastern part of India which houses a significant stretch of local forest cover. Climatically this region is identified to be humid sub-tropical. Here we report first generation of the in situ meteorological observations and leaf area index (LAI) measurements from this site. LAI obtained from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) is compared with the in situ measured LAI. We use these in situ measurements to calculate the total gross photosynthesis (or gross primary productivity, GPP) of the forest using a calibrated model. LAI and GPP show prominent seasonal variation. LAI ranges between 0.75 in winter to 3.25 in summer. Annual GPP is estimated to be \(2.11\,\hbox {kg C m}^{-2} \, \hbox {year}^{-1}\). 相似文献
103.
S. Baruah A. Devi K. G. Bhattacharyya A. Sarma 《International Journal of Environmental Science and Technology》2017,14(2):341-352
Dried, mature leaves of Aegle Marmelos tree were converted to a powder, which was used as a biosorbent for dyes in water with methylene blue as a case study. The biosorbent had a surface area of 52.63 mg/g, and FTIR spectra showed the presence of –COOH, –NH2, –R–SC=O (thioester) and R1–S(=O, =O)-N(–R2, –R3) groups on the surface. The particles were found to be porous in nature from scanning electron micrographs, and EDX measurements showed the elements C, O, Na, Mg, K, Ca and Fe on the surface. Batch adsorption experiments showed that the adsorption of the dye was preferred at near-neutral conditions. Adsorption equilibrium was achieved in ~120 min with maximum dye uptake of 19.9 mg/g. Investigation into the kinetics of adsorption indicated that second-order kinetics gave the best fit to the experimental data, and a rate coefficient of 8.0 × 10?2 to 32.3 × 10?2 g mg?1 min?1 was obtained. 相似文献
104.
Natural Hazards - Regionalization on the basis of the properties of hydro-meteorological data helps in identifying the regions reflecting the similar characteristics which could be useful in... 相似文献
105.
The paper presents an analytical study of the consolidation of a semi-infinite clay layer subjected to a shear load distributed over a rectangular area. Biot's theory is made use of, along with the three displacement functions suggested by Verruijt. A complex Fourier and Laplace transformation technique enables the solution to be obtained in terms of non-dimensional parameters. Settlements and pore pressures under the loaded area are evaluated for two types of surface drainage conditions. Extension of the solutions to point loads is also suggested. The Mandel–Cryer effect is seen in the behaviour of the pore pressure. 相似文献
106.
B.K. Rastogi H.K. Gupta Prantik Mandal H.V.S. Satyanarayana M. Kousalya R. Raghavan Richa Jain A.N.S. Sarma N. Kumar C. Satyamurty 《Journal of Seismology》2001,5(4):609-615
A large destructive earthquake occurred on 26 January 2001 in the region of Kutch, Gujarat, in Western India, with magnitude Mw 7.7. The earthquake caused very heavy damage and a large number of casualties with more than 20,000 deaths. A preliminary study of ground deformation, damage pattern and aftershock distribution is presented. 相似文献
107.
Shishir Raut K S Sundara Sarma D K Das 《Journal of the Indian Society of Remote Sensing》2001,29(4):225-228
Efficacy of irrigation management of wheat and mustard crops grown in Western Yamuna Canal Command area was determined in the present study from agro-climatic data merged with Maximum Likelihood Classified (MXL) satellite image and from irrigation scheduling efficiencies obtained through FAO model CROPWAT. For computing irrigation scheduling efficiencies, amount of water supplied at different growth stages, soil water depletion and crop water need have been taken into account. Agro-meteorological data in combination with MXL classified crop map approximated the deficiency of applied irrigation amount compared to requirement. Irrigations at 35-80 Days After Sowing (DAS) for two times of applications, 30-60-90 DAS for three, 21-50-80-110 DAS in case of four and 20-45-70-90-120 DAS in case of five irrigations have yielded better scheduling efficiencies for wheat than other times of applications in all soil associations. 相似文献
108.
V. V. L. N. Sarma G. Murali Krishna B. Hema Malini K. Nageswara Rao 《Journal of the Indian Society of Remote Sensing》2001,29(1-2):85-91
Interpretation of multi-date satellite imagery has revealed changes in land use/land cover pattern in the Godavari deltaic region during the past 26 years. The area under intensive agriculture has increased from 1459 to 3500 km2 and the extent of wetland from 368 to 648 km2 during the period 1973-1999, while the seasonal fallow has decreased by 2321 km2. Analysis of the climatic data of 1970-1998 from different stations covering the entire 5100 km2 area of the delta indicated that the day time temperatures have decreased by 0.2° C to 0.7° C, while the night time temperatures have increased by 0.5° C to 0.6° C during the past three decades. At the same time the rainfall has increased by about 75 to 479 mm. These trends in the climatic parameters arc attributed to the increased vegetation cover and wetland extent in the Godavari deltaic region. 相似文献
109.
Using the Schwartz-Christofel transformation and numerical integration, the effect of a sloping topographic irregularity on the telluric field measurements in a sedimentary basin is estimated. Results show that in the vicinity of the topographic feature, the distortion introduced would increase with the angle of inclination of the sloping feature. It is noticed that, for moderate inclinations (20°–50°), the telluric field measured near the topographic feature is within 10% of its undisturbed value for distance greater than 0.1H–0.3H from the topographic feature, whereH is the thickness of the sedimentary column overlying the resistive basement. Suitable charts are prepared to aid as means to arrive at the estimates of errors for various angles of inclinations of such topographic feature and also to help in formulating approximate rules of thumb for selection of station sites in a field survey to minimize such topographic effects. 相似文献
110.