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991.
Ram Krishan Sharma 《Astrophysics and Space Science》1987,135(2):271-281
This paper deals with the stationary solutions of the planar restricted three-body problem when the more massive primary is a source of radiation and the smaller primary is an oblate spheroid with its equatorial plane coincident with the plane of motion. The collinear equilibria have conditional retrograde elliptical periodic orbits around them in the linear sense, while the triangular points have long- or short-periodic retrograde elliptical orbits for the mass parameter 0 < crit, the critical mass parameter, which decreases with the increase in oblateness and radiation force. Through special choice of initial conditions, retrograde elliptical periodic orbits exist for the case = crit, whose eccentricity increases with oblateness and decreases with radiation force for non-zero oblateness. 相似文献
992.
R R Navalgund V Jayaraman A S Kiran Kumar Tara Sharma Kurien Mathews K K Mohanty V K Dadhwal M B Potdar T P Singh R Ghosh V Tamilarasan T T Medhavy 《Journal of the Indian Society of Remote Sensing》1996,24(4):207-237
Although data available from various earth observation systems have been routinely used in many resource applications, however there have been gaps, and data needs of applications at different levels of details have not been met. There is a growing demand for availability of data at higher repetivity, at higher spatial resolution, in more and narrower spectral bands etc. Some of the thrust areas of applications particularly in the Indian context are;
- Management of natural resources to ensure sustainable increase in agricultural production,
- Study the state of the environment, its monitoring and assessment of the impact of. various development actions on the environment,
- Updating and generation of large scale topographical maps.
- Exploration/exploitation of marine and mineral resources and
- Operational meteorology and studying various land and oceanic processes to understand/predict global climate changes.
- Moderate spatial resolution (l50-300m), high repetivity (2 Days), minimum set of spectral bands (VIS, NIR, MIR. TIR) full coverage.
- Moderate to high spatial resolution (20-40m), high repetivity (4-6 Days), spectral bands (VIS, MR, MIR, TIR) full coverage.
- High spatial resolution (5-10m) muitispectral data with provision for selecting specific narrow bands (VIS, N1R. MIR), viewing from different angles.
- Synthetic aperture radar operating in at least two frequencies (C, X, Ku), two incidence angles/polarizations, moderate to high spatial resolution (20-40m), high repetivity (4-6 Days).
- Very high spatial resolution (1-2m) data in panchromatic band to provide terrain details at cadastral level (1:10,000).
- Stereo capability (1-2m height resolution) to help planning/execution of development plans.
- Moderate resolution sensor operating in VIS, NIR, MIR on a geostationary platform for observations at different sun angles necessary for the development of canopy reflectance inversion models.
- Diurnal (at least two i.e. pre-dawn and noon) temperature measurements of the earth surface.
- Ocean colour monitor with daily coverage.
- Multi-frequency microwave radiometer, scatterometer. altimeter, atmospheric sounder, etc.
993.
P. Vallabh Sharma 《Pure and Applied Geophysics》1966,65(1):48-53
Summary A simple method is designed for programming the gravity and magnetic calculations of a right circular cylinder (vertical or horizontal) by treating it as a combination of thin rectangular slabs. It takes only a few seconds to compute a profile of each kind and the accuracy is comparable to that obtained by using exact expressions (involving complete elliptic integrals) instead. The method is also applicable to cylindrical bodies of arbitrary cross-section and could as well be used for rapid computation of derivatives of gravity and magnetic anomalies. 相似文献
994.
995.
The effect of ionic interactions on the kinetics of disproportionation of HO2, and the oxidation of Fe(II) and Cu(I) has been examined. The interactions of O2 with Mg2+ and Ca2+ ions in seawater increases the lifetime by 3–5 times compared to water. The effect of OH− on the oxidation of Fe(II) in water and seawater shows a second degree dependence from 5 to 45°C. The effect of salinity on the oxidation of Fe(II) was found to be independent of temperature, while the effect of temperature was found to be independent of salinity. The energy of activation for the overall rate constant was found to be 7 ± 0.5 kcal mol−1.The effect of pH, temperature, salinity and ionic composition on the oxidation of Cu(I) has also been examined. In NaCl solutions from 0.5 to 6 M, the log k for the oxidation was a linear function of pH (6–8) with a slope of 0.2 ± 0.05. The reaction was strongly dependent on the Cl− concentration with variation of
from 0.3 to 340 min from 0.5 to 6 M Cl−. The rates of oxidation of Cu+ and CuCl0 responsible for these effects are dependent upon ionic strength. The energy of activation for the reaction was 8.5–9.9 kcal mol−1 from 0.5 to 6 M. Studies of the oxidation in various NaX salts (X = I−, Br− and Cl−) give rates in the order Cl− > Br− > I− as expected, due to complex formation of Cu+ with X−. 相似文献
996.
Mukul Sharma Erin J. Rosenberg David A. Butterfield 《Geochimica et cosmochimica acta》2007,71(19):4655-4667
We present Os and Sr isotopes and Mg, Os, and Sr concentrations for ridge-crest high-temperature and diffuse hydrothermal fluids, plume fluids and ridge-flank warm spring fluids from the Juan de Fuca Ridge. The data are used to evaluate the extent to which (1) the high- and low-temperature hydrothermal alteration of mid-ocean ridge basalts (MORBs) provides Os to the deep oceans, and (2) hydrothermal contributions of non-radiogenic Os and Sr to the oceans are coupled. The Os and Sr isotopic ratios of the high-temperature fluids (265-353 °C) are dominated by basalts (187Os/188Os = 0.2; 87Sr/86Sr = 0.704) but the concentrations of these elements are buffered approximately at their seawater values. The 187Os/188Os of the hydrothermal plume fluids collected ∼1 m above the orifice of Hulk vent is close to the seawater value (=1.05). The low-temperature diffuse fluids (10-40 °C) associated with ridge-crest high-temperature hydrothermal systems on average have [Os] = 31 fmol kg−1, 187Os/188Os = 0.9 and [Sr] = 86 μmol kg−1, 87Sr/86Sr = 0.709. They appear to result from mixing of a high-temperature fluid and a seawater component. The ridge-flank warm spring fluids (10-62 °C) on average yield [Os] = 22 fmol kg−1, 187Os/188Os = 0.8 and [Sr] = 115 μmol kg−1, 87Sr/86Sr = 0.708. The data are consistent with isotopic exchange of Os and Sr between basalt and circulating seawater during low-temperature hydrothermal alteration. The average Sr concentration in these fluids appears to be similar to seawater and consistent with previous studies. In comparison, the average Os concentration is less than seawater by more than a factor of two. If these data are representative they indicate that low-temperature alteration of MORB does not provide adequate non-radiogenic Os and that another source of mantle Os to the oceans must be investigated. At present, the magnitude of non-radiogenic Sr contribution via low-temperature seawater alteration is not well constrained. If non-radiogenic Sr to the oceans is predominantly from the alteration of MORB, our data suggest that there must be a different source of non-radiogenic Os and that the Os and Sr isotope systems in the oceans are decoupled. 相似文献
997.
S. Bazgeer R. K. Mahey P. K. Sharma A. Sood S. S. Sidhu 《Journal of the Indian Society of Remote Sensing》2006,34(3):269-277
Wheat yield prediction using different agrometeorological indices, spectral index (NDVI, Normalized Difference Vegetation
Index) and trend predicted yield (TPY) were developed in Hoshiarpur and Rupnagar districts of Punjab. On the basis of examination
of Correlation Coefficients (R), Standard Error of Estimate (SEOE) and Relative Deviation (RD) values resulted from different
agromet models, the best agromet subset were selected as Minimum Temperature (Tmin), Maximum Temperature (Tmax) and accumulated Heliothermal Units (HTU) in case of Hoshiarpur district and Minimum Temperature (T--min), accumulated Temperature Difference (TD) and accumulated Pan Evaporation (E) for Rupnagar district at reproductive stage
(2nd week of March) of wheat. It was found that Agromet-Spectral-Trend-Yield model could explain 96 % (SEOE = 87 kg/ha) and 91
% (SEOE = 146 kg/ha) of wheat yield variations for Hoshiarpur and Rupnagar districts, respectively. 相似文献
998.
This paper presents tsunami intensity mapping and damage patterns along the surveyed coast of Tamilnadu (India) of the deadly
Indian Ocean tsunami of December 26, 2004. The tsunami caused severe damage and claimed many victims in the coastal areas
of eleven countries bordering the Indian Ocean. A twelve-stage tsunami intensity scale proposed by Papadopoulos and Imamura
(2001) was followed to assign the intensity at the visited localities. Along the coast of the Indian mainland, tsunami damage
sustained exclusively. Most severe damage was observed in Nagapattinam Beach, Nabiyarnagar, Vellaipalyam, and the Nagapattinam
Port of Nagapattinum District on the east coast and Keelamanakudy village of Kanyakumari District on the western coast of
Tamilnadu. The maximum assigned tsunami intensity was X+ at these localities. Minimum intensity V+ was received along the coast of Thanjavur, Puddukkotai and Ramnathpuram Districts in Palk Strait. The general observation
reported by many people was that the first arrival was a tsunami crest. The largest tsunami waves were first arrivals on the
eastern coast and the second arrivals on the western coast. Along the coast, people were unaware of the tsunami, and no anomalous
behavior of ocean animals was reported. Good correlation was observed between the severity of damage and the presence of shadow
zone of Sri Lanka, reflected waves from Sri Lanka and the Maldives Islands, variation in the width of the continental shelf,
elevation of the coast and the presence of breakwaters. The presence of medu (naturally elevated landmass very close to the
sea shore and elongated parallel to the coast) reduced the impact of the tsunami on the built environment. 相似文献
999.
1000.
A. K. Gupta J. R. Sharma G. Sreenivasan K. S. Srivastava 《Journal of the Indian Society of Remote Sensing》2004,32(1):1-24
Numerous studies have been carried out during last 20-25 years by different agencies to trace the courses of palaeo river
Sarasvati. Varying number of courses of river Sarasvati have been suggested by the different workers in the north-western
region. Taking advantage of the developments in satellite/ sensor and digital image processing technologies an attempt has
been made to rediscover the course of river Sarasvati and solve the controversy regarding its exact course, in the sand covered
Thar desert region. Data available from a variety of ground investigations carried out by different agencies working in this
area have been analyzed in support of confirmation of palaeo channels, along the courses mapped under the present study. The
results indicate that the river Sarasvati had its course through river Ghaggar and did not drain along the Aravalli hills.
Also it did not shift its course drastically and continuously from east to west, as suggested by earlier workers. The image
anomalies indicate that river Sarasvati flowed parallel to the river Indus as an independent river system (closer to the north-western
Indian border) and did not flow through present course of river Nara. The findings raise the doubt that ‘Rise along Delhi-Hardwar
ridge’ as suggested by earlier workers was the main cause for west-ward shift of Sarasvati river and ultimate drainage desiccation
in the northwestern region. The analysis indicates towards rise in Himalayas/ Siwaliks and consequent displacements in the
Siwaliks and its foot hills region (in the form of Yamuna and Satlej tear faults) as the main cause for drainage desiccation
and disappearance of river Sarasvati. 相似文献