全文获取类型
收费全文 | 111篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 10篇 |
地球物理 | 30篇 |
地质学 | 41篇 |
海洋学 | 24篇 |
天文学 | 8篇 |
自然地理 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有118条查询结果,搜索用时 15 毫秒
61.
62.
Sea Surface Height (SSH) variability in the Indian Ocean during 1993-1995 is studied using TOPEX/POSEIDON (T/P) altimetry data. Strong interannual variability is seen in the surface circulation of the western Arabian Sea, especially in the Somali eddy structure. During the Southwest (SW) monsoon, a weak monsoon year is characterized by a single eddy system off Somalia, a strong or normal monsoon year by several energetic eddies. The Laccadive High (LH) and Laccadive Low (LL) systems off southwest India are observed in the altimetric SSH record. The variability of the East India Coastal Current (EICC), the western boundary current in the Bay of Bengal, is also detected. Evidence is found for the propagation of Kelvin and Rossby waves across the northern Indian Ocean; these are examined in the context of energy transfer to the western boundary currents, and associated eddies. A simple wind-driven isopycnal model having three active layers is implemented to simulate the seasonal changes of surface and subsurface circulation in the North Indian Ocean and to examine the response to different wind forcing. The wind forcing is derived from the ERS-1 scatterometer wind stress for the same period as the T/P altimeter data, enabling the model response in different (active/weak) monsoon conditions to be tested. The model output is derived in 10-day snapshots to match the time period of the T/P altimeter cycles. Complex Principal Component Analysis (CPCA) is applied to both altimetric and model SSH data. This confirms that long Rossby waves are excited by the remotely forced Kelvin waves off the southwest coast of India and contribute substantially to the variability of the seasonal circulation in the Arabian Sea. 相似文献
63.
Evaluation of atmospheric corrections on hyperspectral data with special reference to mineral mapping 总被引:1,自引:0,他引:1
Hyperspectral images have wide applications in the fields of geology, mineral exploration, agriculture, forestry and environmental studies etc. due to their narrow band width with numerous channels. However, these images commonly suffer from atmospheric effects, thereby limiting their use. In such a situation, atmospheric correction becomes a necessary pre-requisite for any further processing and accurate interpretation of spectra of different surface materials/objects. In the present study, two very advance atmospheric approaches i.e. QUAC and FLAASH have been applied on the hyperspectral remote sensing imagery. The spectra of vegetation, man-made structure and different minerals from the Gadag area of Karnataka, were extracted from the raw image and also from the QUAC and FLAASH corrected images. These spectra were compared among themselves and also with the existing USGS and JHU spectral library. FLAASH is rigorous atmospheric algorithm and requires various parameters to perform but it has capability to compensate the effects of atmospheric absorption. These absorption curves in any spectra play an important role in identification of the compositions. Therefore, the presence of unwanted absorption features can lead to wrong interpretation and identification of mineral composition. FLAASH also has an advantage of spectral polishing which provides smooth spectral curves which helps in accurate identification of composition of minerals. Therefore, this study recommends that FLAASH is better than QUAC for atmospheric correction and correct interpretation and identification of composition of any object or minerals. 相似文献
64.
K. Gopala Reddy G. Bharathi A. Ravi Kumar M. V. Subrahmanyam K. Muni Krishna 《Journal of Earth System Science》2003,112(2):267-281
Time series measurements of radiative fluxes were made onboard INS Sagardhwani (SD) in the south Bay of Bengal near DS3 (13‡N
and 87‡E) during the BOBMEX field experiment. An inter-comparison experiment conducted at DS3 showed that the radiative fluxes
measured by Kipp and Zonen, Albedo meter and net Pyrgeometer onboard SD and by Eppley radiometers onboard ORV Sagar Kanya
(SK) are well matched. It may be mentioned that the measurements showed consistency and good agreement between SD and SK ships,
even though no Gimbal mounting was used for radiation instruments onboard SD.
The main aim of the experiment was collection of high quality radiation data during the monsoon period, which can give an
insight into the nature of the ocean-atmosphere coupling. The data on the four radiative fluxes collected on SD are averaged
at 5 minute intervals and then hourly and daily averages have been computed. The hourly shortwave albedo and the atmospheric
transmission factor are also computed and the variation of albedo in relation to the solar altitude and the transmissivity
factor (TF) are studied. The mean albedo over the south Bay of Bengal under clear, partly cloudy and overcast skies are found
to be 0.05, 0.07 and 0.2 respectively. 相似文献
65.
Ocean Dynamics - The present study focuses on the variability of subsurface ocean temperature and associated planetary waves (oceanic Kelvin and Rossby waves) in the Indian Ocean during the boreal... 相似文献
66.
Francis Pavanathara Augustine Jithin Abraham Kaduvathazham Chatterjee Abhisek Mukherjee Arnab Shankar Doraiswamy Vinayachandran Puthenveettil Narayanamenon Ramakrishna Surireddi Satya Venkata Siva 《Ocean Dynamics》2020,70(3):387-404
Ocean Dynamics - The structure and variability of undercurrents in the East India Coastal Current (EICC), which is the western boundary current system in the Bay of Bengal (BoB), and the mechanisms... 相似文献
67.
Flood modelling inputs used to create flood hazard maps are normally based on the assumption of data stationarity for flood frequency analysis. However, changes in the behaviour of climate systems can lead to nonstationarity in flood series. Here, we develop flood hazard maps for Ho Chi Minh City, Vietnam, under nonstationary conditions using extreme value analysis, a coupled 1D–2D model and high-resolution topographical data derived from LiDAR (Light Detection and Ranging) data. Our findings indicate that ENSO (El Niño Southern Oscillation) and PDO (Pacific Decadal Oscillation) influence the magnitude and frequency of extreme rainfall, while global sea-level rise causes nonstationarity in local sea levels, having an impact on flood risk. The detailed flood hazard maps show that areas of high flood potential are located along river banks, with 0.60 km2 of the study area being unsafe for people, vehicles and buildings (H5 zone) under a 100-year return period scenario. 相似文献
68.
Mineralogical changes and geotechnical properties of an expansive soil interacted with caustic solution 总被引:1,自引:0,他引:1
Puvvadi Venkata Sivapullaiah Gullapalli Sankara Mehter M. Allam 《Environmental Earth Sciences》2010,60(6):1189-1199
The type and amount of clay mineral plays an important role in the behaviour of fine-grained soils. Clay minerals are the
primary source and moisture is often the external agent of swelling in soils. Also soils may exhibit increased/reduced swelling
due to interaction with chemicals. Alkalis used in industrial operations are one such example. Concentrations of alkali and
mineral type are the key factors in such interactions. The present paper reports the changes in the properties of an expansive
Black Cotton soil containing a mixed layer mineral, rectorite upon interaction with high concentration caustic solutions.
X-ray diffraction studies have shown that the rectorite present in the soil undergoes changes with increase in the concentration
of alkali. Saponite gets transformed to nantronite. Small amount of kaolinitic mineral present in the soil also reacts with
alkali producing some changes in its mineralogy. Many hydroxides are produced. Differential thermal analysis studies have
been supportive of these changes. Consequent of these changes, the soil-specific surface increases, changes its Atterberg
limits and free swell volume increases. The results have been supported by the characteristics and behaviour of samples contaminated
in the field with alkali from an alumina extraction plant. 相似文献
69.
J. Venkata Ratnam Filippo Giorgi Akshara Kaginalkar Stefano Cozzini 《Climate Dynamics》2009,33(1):119-139
A regional coupled atmosphere–ocean model was developed to study the role of air–sea interactions in the simulation of the
Indian summer monsoon. The coupled model includes the regional climate model (RegCM3) as atmospheric component and the regional
ocean modeling system (ROMS) as oceanic component. The two-way coupled model system exchanges sea surface temperature (SST)
from the ocean to the atmospheric model and surface wind stress and energy fluxes from the atmosphere to the ocean model.
The coupled model is run for four years 1997, 1998, 2002 and 2003 and the results are compared with observations and atmosphere-only
model runs employing Reynolds SSTs as lower boundary condition. It is found that the coupled model captures the main features
of the Indian monsoon and simulates a substantially more realistic spatial and temporal distribution of monsoon rainfall compared
to the uncoupled atmosphere-only model. The intraseasonal oscillations are also better simulated in the coupled model compared
to the atmosphere-only model. These improvements are due to a better representation of the feedbacks between the SST and convection
and highlight the importance of air–sea coupling in the simulation of the Indian monsoon. 相似文献
70.
K. S. R. Murthy V. Subrahmanyam A. S. Subrahmanyam G. P. S. Murty K. V. L. N. S. Sarma 《Natural Hazards》2010,55(2):167-175
The South Indian (Peninsular) Shield which includes both the Eastern and Western Continental Margins of India is not as stable
as it was originally thought of. The importance of intraplate seismicity within this Shield has recently been realized with
some devastating earthquakes that occurred during the last few decades. It is also significant to note that most of the Precambrian
tectonic lineaments in this Shield are oriented in either a NW–SE or W–E direction, joining the eastern offshore. In contrast,
the western margin has an elevated coast, associated with a linear coast parallel escarpment, particularly on the southern
side, superimposed by Deccan Trap volcanics on the northern side. The fault reactivation and the associated seismicity are
hence more predominant on the east coast. Recent geophysical studies delineated land–ocean tectonics (LOTs) over the eastern
margin, in some cases associated with moderate seismicity as a result of the compressional stress acting on the Indian Plate.
Though the Eastern Continental Margin of India (ECMI) is considered as a passive margin, coastal seismicity due to the reactivation
of the pre-existing tectonic lineaments extending offshore represents a potential natural hazard. In this context, the ECMI
appears to be much more vulnerable compared to its counterpart on the west. 相似文献