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441.
In recent years, the United Arab Emirates (UAE) has experienced an unprecedented growth which is coupled with the increase in seismic activity in the surroundings. Previous studies presents significant variations in their results whereas some recent studies although very detailed focus on only few cities. This study reviews the results of previous studies and presents new findings for the whole of UAE based on the improved source model and use of next generation attenuation (NGA) equations. The peak ground accelerations, spectral accelerations and deaggregation of hazard for major cities are presented. Moreover, the breakdown of the range of mapped spectral accelerations (S 0.2 and S 1) is proposed to form the basis for the development of site amplification factors in subsequent studies. The results of this study indicate almost similar values of ground motion compared to some recently published studies and smaller values compared to some earlier studies. 相似文献
442.
A new bivariate Gamma distribution generated from functional scale parameter with application to drought data 总被引:1,自引:0,他引:1
Muhammad Mohsin Albrecht Gebhardt Jürgen Pilz Gunter Spöck 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(5):1039-1054
Univariate and bivariate Gamma distributions are among the most widely used distributions in hydrological statistical modeling and applications. This article presents the construction of a new bivariate Gamma distribution which is generated from the functional scale parameter. The utilization of the proposed bivariate Gamma distribution for drought modeling is described by deriving the exact distribution of the inter-arrival time and the proportion of drought along with their moments, assuming that both the lengths of drought duration (X) and non-drought duration (Y) follow this bivariate Gamma distribution. The model parameters of this distribution are estimated by maximum likelihood method and an objective Bayesian analysis using Jeffreys prior and Markov Chain Monte Carlo method. These methods are applied to a real drought dataset from the State of Colorado, USA. 相似文献
443.
Recharge to a saline, unconfined shallow-water-table aquifer is normally considered as an irrecoverable loss of water, but
such thinking could be reviewed empirically. The use of an appropriate groundwater harvesting system does not only provide
an opportunity to recover this lost water, but can also help in catchment salinity management and improvement. Agricultural-based
land-drainage systems such as those that use serial biological concentration (SBC) of salts, provide examples of such harvesting
methods. The impact of groundwater harvesting has been assessed on the hydro-salinity of a saline catchment in southeastern
Australia through modeling. For both the below average rainfall and very wet years, the “do nothing” scenario resulted in
increasing salinization in the catchment. However, after introducing a SBC system, groundwater salinity showed a decreasing
trend while hydraulic heads tended to stabilize around the depth of subsurface collector wells. However, for a successful
groundwater harvesting system, proper understanding of the groundwater flows and salt mobilization associated with a catchment
is necessary. The outcomes of this modelling study have the potential to address similar issues (salinization) and/or needs
(water harvesting) existing elsewhere in the world, particularly in semi-arid regions.
相似文献
Muhammad Nadeem AsgharEmail: |
444.
Stephan Schulz Rike Becker Juan Carlos Richard-Cerda Muhammad Usman Tim aus der Beek Ralf Merz Christoph Schüth 《水文研究》2021,35(3):e14077
Information on water balance components such as evapotranspiration and groundwater recharge are crucial for water management. Due to differences in physical conditions, but also due to limited budgets, there is not one universal best practice, but a wide range of different methods with specific advantages and disadvantages. In this study, we propose an approach to quantify actual evapotranspiration, groundwater recharge and water inflow, i.e. precipitation and irrigation, that considers the specific conditions of irrigated agriculture in warm, arid environments. This approach does not require direct measurements of precipitation or irrigation quantities and is therefore suitable for sites with an uncertain data basis. For this purpose, we combine soil moisture and energy balance monitoring, remote sensing data analysis and numerical modelling using Hydrus. Energy balance data and routine weather data serve to estimate ET0. Surface reflectance data from satellite images (Sentinel-2) are used to derive leaf area indices, which help to partition ET0 into energy limited evaporation and transpiration. Subsequently, first approximations of water inflow are derived based on observed soil moisture changes. These inflow estimates are used in a series of forward simulations that produce initial estimates of drainage and ETact, which in turn help improve the estimate of water inflow. Finally, the improved inflow estimates are incorporated into the model and then a parameter optimization is performed using the observed soil moisture as the reference figure. Forward simulations with calibrated soil parameters result in final estimates for ETact and groundwater recharge. The presented method is applied to an agricultural test site with a crop rotation of cotton and wheat in Punjab, Pakistan. The final model results, with an RMSE of 2.2% in volumetric water content, suggest a cumulative ETact and groundwater recharge of 769 and 297 mm over a period of 281 days, respectively. The total estimated water inflow accounts for 946 mm, of which 77% originates from irrigation. 相似文献
445.
Muhammad BASHARAT Joachim ROHN Mirza Shahid BAIG Muhammad Rustam KHAN Markus SCHLEIER 《山地科学学报》2014,11(1):19-30
The SPOT image analysis in Muzaffarabad Azad Kashmir,northwest Himalayas,Pakistan reveals that the Kashmir earthquake 2005 triggered a number of coseismic mass movements along the hanging wall block of the Muzaffarabad Fault.The Neelidandi and Langarpura rock falls have been identified as two major reactivated mass movements with an estimated volume of 3.1 × 106m3and 5.76 × 106m3,respectively.The Neelidandi and Langarpura mass movements were initiated during earthquake in the direction of northwest-southeast extension and northeastsouthwest directed thrusting,respectively.The Neelidandi rock fall occurred in sheared cherty dolomites and limestones of the Cambrian Muzaffarabad Formation,whereas the Langarpura rock fall occurred in alternating clays,shales,claystones,siltstones and sandstones of the Miocene Murree Formation.These rock units along the fault are highly fractured and jointed.The geotechnical maps and geological longitudinal profiles show the relationship between the geometrical characteristics and mechanism of these mass movements.Their characteristics were analyzed according to the role of topographic,seismic,geological and tectonic factors.The steep topography,sheared rocks,lithology,coseismic uplift and strong ground shaking of the hanging wall block along Muzaffarabad Fault facilitated the gravity collapse of these mass movements. 相似文献
446.
Salih Muhammad Awadh 《Environmental Earth Sciences》2012,66(8):2247-2256
Five dust storms that occurred in 2008 (15 March, 11 April, 28 April, 25, May and 26 June) in addition to the many sand dunes disseminated in the Western Desert of Iraq are sampled. The worse dust storm that occurred in Iraq in 11 April, 2008 covered 75% of the Iraq area and deposited 6.9?million tons approximately as a total weight of fallout during just 8?h, declining temperature 6°C. During the episodes of dust storms, visibility decreased enormously, no more than 30?m. Many people were taken to hospitals after sustaining breathing problems. Some of them died. Clay fraction is the dominant part in the dust storms forming 70% besides a little silt (20.6%) and sand (9.4%), then classified as mature arkose of clay to sandy clay, whereas sand dunes are formed from 72.7% sand, 25.1% silt and 2.19% clay, then classified as mature arkose of silty sand. Sand dunes have much maturity. Mineralogical composition of dust storms and sand dunes are Quartz (49.2%, 67.1%), feldspar (4.9%, 20.9%), calcite (38%, 5%), gypsum (4.8%, 0.4%), dolomite (0.8%, 1%) and heavy minerals (3.2%, 6.6%), respectively. Heavy mineral suites in the dust storms are represented by zircon, pyroxene, hornblende, chlorite and magnetite; whereas the sand dunes are represented by zircon, tourmaline, garnet and pyroxene, concentrated within sand fraction. Heavy minerals according to satellite images revealed the dry land of Sahara Desert in North Africa and the Arabian Peninsula as well as Syria and Jordan were a major source of the dust storms that have occurred in Asia, including Iraq. 相似文献
447.
Mautaz Al-Dabbas Salih Muhammad Awadh Ayad Abed Zaid 《Arabian Journal of Geosciences》2013,6(2):491-503
This study deals with the mineralogical and geochemistry of the Euphrates Formation (Lower Miocene) in Bahr Al-Najaf area in order to assess the lithofacies of the Euphrates Formation for Portland cement manufacturing. Petrographic and mineralogical studies were carried out on 210 core samples, collected from 21 boreholes, and showed that calcite is the dominant mineral with few amounts of quartz, gypsum, feldspar, and a rare amount of dolomite. Clay mineral suites (palygorskite, kaolinite, montmorillonite, and illite) formed about 5% from the total mineral composition. Palygorskite precipitated directly in alkali shallow water rich with Si and Mg ions. Chemical weathering of feldspar under acidic conditions participated in formation of Kaolinite. Geochemistry showed that there is no high variation in chemical constituents with depth, and the average of CaO (51.5), MgO (0.83), SO3 (0.54), SiO2 (4.3), Fe2O3 (0.45), Al2O3 (0.93), L.O.I (40.7), Na2O3 (0.08), K2O (0.14), and Cl- (0.1) qualified the lithofacies of Euphrates Formation to be raw materials suitable for manufacturing the Portland cement. Triangle Block method is applied to estimate the reserve on square area (2?×?2 km2) which is computed to be 63 million tons of medium-tough limestone as potential probable reserve. 相似文献
448.
Muhammad MURTAZA Abdul Hadi Abd RAHMAN Joerg MUTTERLOSE Najiatun NAJLA Mazshurraiezal Bin NASIR 《《地质学报》英文版》2021,95(2):333-341
Discovery of the remains of belemnites referred to the Hibolithes sp. from the Jurassic–Cretaceous Pedawan Formation in Sarawak, on the island of Borneo(Malaysia) comprises four fragments of belemnite rostra. The specimens are characterized by multiple fractures and vein filling. Two fragments measuring about 130 mm are relatively intact, with only part of the alveolar region missing; a third piece represents the middle part of a rostrum, and the fourth specimen is too fragmentary to be assigned to any specific part of the rostrum. Based on specimen characteristics, a Tithonian–Hauterivian age is plausible. The sedimentary succession that yielded the belemnite material comprises thick shale that reflects the Te division of Bouma sequence. The occurrence of a Hibolithes taxon in the uppermost Jurassic to lowermost Cretaceous Pedawan Formation sediments in Borneo reflects a near to global palaeobiogeographic distribution of this genus. 相似文献
449.
Danish KHAN LIANG Chao QIU Longwei Kamran MIRZA WANG Yelei Muhammad KASHIF Saif Ur REHMAN WANG Yuzhe TENG Jianbin 《《地质学报》英文版》2023,97(2):589-609
The effect of various depositional parameters including paleoclimate, paleosalinity and provenance, on the depositional mechanism of lacustrine shale is very important in reconstructing the depositional environment. The classification of shale lithofacies and the interpretation of shale depositional environment are key features used in shale oil and gas exploration and development activity. The lower 3rd member of the Eocene Shahejie Formation(Es3x shale) was sel... 相似文献
450.
This article explores the role of geographical context in generating a stigmatised identity among residents of Tara rural subdivisions in the coal seam gas fields in Queensland’s Western Downs. The research was based on qualitative interviews with Tara ‘Blockies’, as these residents are commonly referred to, that revealed how their existence in the middle of an agrarian region resulted in the assignation of a stigma that has marked them as different, and subsequently devalued their status. We explain that this distinction and category division of the normals, referring to Tara’s Agrarian residents, from the ‘stigmatised’ led to an antagonistic relationship that prevented successful socio-cultural assimilation. We demonstrate how an immoral place becomes disadvantaged, resulting in poor well-being, and how imposed labels threaten the self-esteem of its occupants. 相似文献