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41.
The French Transportable Laser Ranging System (FTLRS) was deployed in the calibration site of satellite radar altimeters in Corsica over the 2002 and 2005 campaigns. The paper describes the different steps of SLR data processing. The average arcs RMS obtained are about 1–2 cm for Lageos-1&;-2, Starlette and Stella satellites; it is shown that the best results of satellite orbits determination and geocentric positioning are obtained with Eigen-Grace03s gravity model. The difference of FTLRS absolute 3D positioning, between 2002 and 2005, of about 7.7 mm (i.e., 2.6 mm/yr) is less than residual errors of ITRF2005 velocities (of about 4.3 mm/yr).  相似文献   
42.
We calculate the gluon self-mass and the QCD coupling constant at finite temperature in the real-time formalism up to the first loop level. The expressions are derived in a form that is valid for all temperature ranges in QCD. Using these results the dynamically generated mass of gluons and the plasma screening length can be determined from their effective potential.  相似文献   
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Landslides are the most established geological hazards in the frontal fold–thrust belt of Northwestern Himalaya comprising of Siwaliks and Murree strata. The continuous rainfall from 2 to 6 September, 2014 caused a massive landslide at village Sadal in Udhampur district of Jammu and Kashmir state. The landslide occurred in the early morning of September 6, 2014, destroying entire Sadal habitation comprising 45 houses, and killing 41 people and more than 500 domestic animals. Google earth images of pre and post-landslide events along with the field measurements show the kinematics of upper and lower parts of the slide. Horizontal and vertical components of displacement and mode of failure suggest the landslide as of complex nature. The shallow subsurface geophysical imaging through Ground Penetrating Radar (GPR) survey shows the failure plane composed of friable mudstone bed underlain by massive mudstone and overlain by cross-bedded sandstone. The depth of debris material above the failure plane ranges from 6 m at Site S1a-b to 10 m at Site-S2b and 20 m at Site S3a. The velocity analysis of Site-3 shows four thick layers represented from bottom to surface by L1—sandstone (V?=?0.16 m/ns, travel time?=?356.36 ns), L2—mudstone (V?=?0.17 m/ns, travel time?=?288.48 ns), L3—massive mudstone (V?=?0.19 m/ns, travel time 220.68 ns), and L4—cross-laminated sandstone (V?=?0.20 m/ns, travel time?=?77.58 ns) overlaying the failure plane. The study shows the landslide occur along the western limb of a fold identified during the present work. We mapped an old landslide on the same limb which shows 5–6 m-thick subsurface debris material with thick rock fragments involved in the landslide process. The detailed geological and geophysical investigations suggest that both the landslides were triggered by extreme rain fall events.  相似文献   
46.
The present work has been carried out in Moradabad, one of the important cities in the state of Uttar Pradesh. The main focus of the study is to estimate the extent of anthropogenic contamination in shallow groundwater of the area. For this purpose, total 188 groundwater samples collected from handpumps in pre- and post monsoon period of 2012 and 2013 (47 in each season) were analyzed for physico-chemical parameters such as pH, EC, TDS, major cations (Ca, Mg, Na, and K) and anions (Cl, HCO3, SO4, NO3 and F). The results of the analysis suggested that groundwater is slightly alkaline, hard to very hard in nature, average TDS values were found to be more than 1000 mg/l, which gives a clear evidence of anthropogenic influences. To estimate the extent of contamination, the information on relatively unpolluted groundwater systems occurring in different terrains including Ganga plain where the groundwater was relatively unaffected by anthropogenic activities is used. The estimated pristine chemical composition of groundwater of different terrains used in the present study was compared with the groundwater of Moradabad city. This comparison showed that Moradabad city with the highest Na, K, Cl, SO4 and NO3 values being 440 mg/l, 96 mg/l, 537 mg/l, 537 mg/ l and 244 mg/l, respectively, is one of the most polluted urban centres within the Ganga plain. It may be suggested that values of > 50 mg/l for Na, > 10 mg/l for K, > 25 mg/l for Cl, > 50 mg/l for SO4 and > 10 mg/l for NO3 have their respective sources in anthropogenic activities such as agricultural in the peripheral region, human and animal wastes, leakages from drains and septic tanks, landfill leachates and industrial effluents.  相似文献   
47.
Miraj  M. A. F.  Ali  A.  Ahsan  N.  Afgan  Sh.  Saleem  R. F. 《Geotectonics》2020,54(6):807-820
Geotectonics - Comparative analysis of three randomly chosen salt structures (diapir A, diapir B and diapir C) of the Southern North Sea has been presented through the interpretation and...  相似文献   
48.
Linear and nonlinear properties of coupled modes in a magnetized quantum plasma in the presence of electron Fermi pressure are studied in a nonuniform magnetoplasma composed of electrons, ions, and extremely massive and negatively charged immobile dust grains. Stationary solutions of the nonlinear equations that govern the dynamics of coupled modes are presented. It is found that electrostatic dipolar vortex structure can form in such a plasma. The dipolar structures in dense plasmas are observed to be formed on a much shorter scalelength by comparison with their classical counterparts. It is found that the increasing Fermi temperature shortens the scalelength over which the nonlinear coherent structures are formed. The relevance of the present investigation with regard to the dense astrophysical plasmas is also pointed out.  相似文献   
49.
In this paper, sediment texture, clay mineral composition, and δ 18O data on Globigerinoides ruber of a sediment core collected from a water depth of 250 m near Landfall Island, Bay of Bengal, is presented to understand paleoenvironmental shifts during the Mid–Late Holocene period. From the sediment core, five organic carbon-rich samples were radiocarbon dated and the reservoir-corrected ages range from 6,078 to 1,658 years BP. The marine sediment core is represented dominantly by clayey silt with incursions of coarser components that occur around 6,000, 5,400, and 3,400 years BP. The sedimentation of the coarser detritus is due to strengthened southwest monsoon (SWM) since 6,500 to 5,400 years BP. Clay minerals are represented by smectite, illite, kaolinite, and chlorite in varying amounts. High kaolinite content and K/C ratio indicate intense SWM and strong bedrock weathering from the hinterland (~6,500–5,400 years BP). Incidence of smectite (48.82 to 25.09 %) and chlorite/illite (C/I) ratio (0.56 to 0.28) indicate an overall weakened southwest monsoon since 6,000 to 2,000 years BP with a brief incursion of extremely reduced SWM around 4,400 to 4,200 years BP. This is corroborated with the oxygen isotope on G. ruber that reveals a significant shift in the isotopic values ~4,300 years BP (?3.39?‰), indicating weakening in SWM. Subsequently, fluctuations in the intensity of SWM are observed since 2,000 years to present.  相似文献   
50.
Electrostatic solitary structures are studied in uniform and nonuniform magnetoplasmas with superthermal electrons. In the linear analysis, the differences in the acoustic frequencies for Maxwellian, Cairns, and Kappa distributed electrons for both homogeneous and inhomogeneous plasmas are highlighted and discussed. It is shown that using the linear dispersion relation, nonlinear Zakharov-Kuznetsov (ZK) equation can be derived both for the homogeneous and inhomogeneous magnetoplasmas. The solution of the ZK equation is presented using the tangent hyperbolic method. It is found that the increasing magnetic field and the angle of propagation enhances the amplitude whereas the increasing number density mitigates the amplitude of the acoustic drift solitary wave. Furthermore, it is observed that the amplitude of the solitary structure is maximum for Cairns, intermediate for Maxwellian, and minimum for the Kappa distributed electrons. The results presented in this paper may be beneficial to understand the formation of electrostatic drift solitary waves in planetary environments where the nonthermal population of electrons are observed by various satellite missions.  相似文献   
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