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1.
Suhail Gumaan Masda Mashhoor Ahmed Al-Wardat Jiyaulla Khan Moula Khan Pathan 《天文和天体物理学研究(英文版)》2018,(6)
The best physical and geometrical parameters of the main sequence close visual binary system(CVBS), HIP 105947, are presented. These parameters have been constructed conclusively using Al-Wardat's complex method for analyzing CVBSs, which is a method for constructing a synthetic spectral energy distribution(SED) for the entire binary system using individual SEDs for each component star. The model atmospheres are in its turn built using the Kurucz(ATLAS9) line-blanketed plane-parallel models. At the same time, the orbital parameters for the system are calculated using Tokovinin's dynamical method for constructing the best orbits of an interferometric binary system. Moreover, the mass-sum of the components, as well as the ?θ and ?ρ residuals for the system, is introduced. The combination of Al-Wardat's and Tokovinin's methods yields the best estimations of the physical and geometrical parameters. The positions of the components in the system on the evolutionary tracks and isochrones are plotted and the formation and evolution of the system are discussed. 相似文献
2.
Khan Mohammad Rasheed Tariq Zeeshan Abdulraheem Abdulazeez 《Natural Resources Research》2020,29(6):4017-4029
Natural Resources Research - Optimization and monitoring schemes for oil well and reservoir system require accurate estimation of production rate. Real-time monitoring is conducted typically using... 相似文献
3.
The relation between the water discharge (Q) and suspended sediment concentration (SSC) of the River Ramganga at Bareilly, Uttar Pradesh, in the Himalayas, has been modeled using Artificial Neural Networks (ANNs). The current study validates the practical capability and usefulness of this tool for simulating complex nonlinear, real world, river system processes in the Himalayan scenario. The modeling approach is based on the time series data collected from January to December (2008–2010) for Q and SSC. Three ANNs (T1-T3) with different network configurations have been developed and trained using the Levenberg Marquardt Back Propagation Algorithm in the Matlab routines. Networks were optimized using the enumeration technique, and, finally, the best network is used to predict the SSC values for the year 2011. The values thus obtained through the ANN model are compared with the observed values of SSC. The coefficient of determination (R2), for the optimal network was found to be 0.99. The study not only provides insight into ANN modeling in the Himalayan river scenario, but it also focuses on the importance of understanding a river basin and the factors that affect the SSC, before attempting to model it. Despite the temporal variations in the study area, it is possible to model and successfully predict the SSC values with very simplistic ANN models. 相似文献
4.
Muhammad Khurshid Mohammad Nafees Abdullah Khan Mehmet Somuncu Ashfaq Ahmad Khan Wajid Rashid 《地理学报(英文版)》2019,29(10):1758-1770
Journal of Geographical Sciences - Pastoralism is a viable socio-economic system-shaped by landless and agro-pastoral communities in many pastoral regions of the world. This system is mainly based... 相似文献
5.
Analysis of dry and wet climate characteristics at Uttarakhand (India) using effective drought index
Malik Anurag Kumar Anil Kisi Ozgur Khan Najeebullah Salih Sinan Q. Yaseen Zaher Mundher 《Natural Hazards》2021,105(2):1643-1662
Natural Hazards - Drought is a complex natural disaster that adversely affects human life and the ecosystem. A variety of drought indexes are available for monitoring meteorological drought events.... 相似文献
6.
Prosanta Kumar Khan 《International Journal of Earth Sciences》2011,100(7):1749-1758
Present study addresses the role of major plate-driving forces, particularly the slab pull and slab resistive forces, for
the generation of 26 December 2004 M
w > 9.0 off Sumatra megathrust earthquake. Major controls on the plate-driving forces are normally visualized through age,
speed, and average dip of the slab during subduction. Wide variation in age, plate obliquity, stress obliquity, subduction
rate, dip angle, and flexing depth of the subducting oceanic lithosphere between Andaman and Sumatra thus allowed us for quantitative
evaluation of the slab pull (F
SP) and slab resistive (F
SR) forces in three well-defined sectors (I, II and III). Computed values of these forces in the three sectors: (1) F
SP = 1.29 × 1013 N/m, F
SR = 1.41 × 1013 N/m; sector I, (2) F
SP = 2.10 × 1013 N/m, F
SR = 1.13 × 1013 N/m; sector II, and (3) F
SP = 2.08 × 1013 N/m, F
SR = 2.72 × 1013 N/m; sector III clearly suggest a spatial variation of stress regime in the subducting oceanic lithosphere. Excess F
SR in sectors I and III are interpreted as the causative forces behind the triggering of major seismic energy bursts near Sumatra
and Andaman on 26 December 2004. A gap of minimum seismic energy burst near Great Nicobar possibly was controlled by the excess
of F
SP in sector II. This study further advocates that the cyclic stress, resulted from unbalanced component of slab resistive force,
had a definite control on the occurrence of 2004 off Sumatra megathrust earthquake around the flexing zone of the subducting
lithosphere. 相似文献
7.
For mineral resource assessment, techniques based on fuzzy logic are attractive because they are capable of incorporating uncertainty associated with measured variables and can also quantify the uncertainty of the estimated grade, tonnage etc. The fuzzy grade estimation model is independent of the distribution of data, avoiding assumptions and constraints made during advanced geostatistical simulation, e.g., the turning bands method. Initially, fuzzy modelling classifies the data using all the component variables in the data set. We adopt a novel approach by taking into account the spatial irregularity of mineralisation patterns using the Gustafson–Kessel classification algorithm. The uncertainty at the point of estimation was derived through antecedent memberships in the input space (i.e., spatial coordinates) and transformed onto the output space (i.e., grades) through consequent membership at the point of estimation. Rather than probabilistic confidence intervals, this uncertainty was expressed in terms of fuzzy memberships, which indicated the occurrence of mixtures of different mineralogical phases at the point of estimation. Data from different sources (other than grades) could also be utilised during estimation. Application of the proposed technique on a real data set gave results that were comparable to those obtained from a turning bands simulation. 相似文献
8.
GIS-based impact assessment of land-use changes on groundwater quality: study from a rapidly urbanizing region of South India 总被引:4,自引:0,他引:4
Haris H. Khan Arina Khan Shakeel Ahmed Jerome Perrin 《Environmental Earth Sciences》2011,63(6):1289-1302
This study attempts to assess the influence of changing land-use patterns on the groundwater quality of the hard rock aquifer
system in the Maheshwaram watershed, near Hyderabad, India. The study area is a rapidly urbanizing region with land development
progressing at a fast pace. To study the impact of this rapid urbanization and overall land-use transition, a groundwater
quality index (GQI) was prepared within a geographical information system (GIS). The GQI integrates the different water quality
parameters to give a final index value that can be used for spatio-temporal comparisons. The land-use transitions were closely
monitored from 2003 to 2008 using multispectral satellite images. The land-use pattern has changed drastically with an increase
in the built-up area at the expense of other land uses. The analysis reveals a rapid deterioration of groundwater quality
related mainly to the increase in built-up land with unsewered sanitation and poultry farms. Seasonal variability of the groundwater
quality was also assessed. Mean GQI decreased from 84.16 to 83.26 over a period of 5 years from 2003 to 2008, while seasonal
variability of water quality increased. GQI and Seasonal Variability of water quality were integrated in GIS to yield a groundwater
sustainability map, in terms of water quality. Zones of sustainable and unsustainable groundwater use were demarcated for
better decision making related to municipal land allotment in this rapidly urbanizing region. 相似文献
9.
Sarat Kumar Das Pijush Samui Shakilu Zama Khan Nagarathnam Sivakugan 《Central European Journal of Geosciences》2011,3(4):449-461
Stability with first time or reactivated landslides depends upon the residual shear strength of soil. This paper describes prediction of the residual strength of soil based on index properties using two machine learning techniques. Different Artificial Neural Network (ANN) models and Support Vector Machine (SVM) techniques have been used. SVM aims at minimizing a bound on the generalization error of a model rather than at minimizing the error on the training data only. The ANN models along with their generalizations capabilities are presented here for comparisons. This study also highlights the capability of SVM model over ANN models for the prediction of the residual strength of soil. Based on different statistical parameters, the SVM model is found to be better than the developed ANN models. A model equation has been developed for prediction of the residual strength based on the SVM for practicing geotechnical engineers. Sensitivity analyses have been also performed to investigate the effects of different index properties on the residual strength of soil. 相似文献
10.
A. Yu. Bundel V. N. Kryzhov Young-Mi Min V. M. Khan R. M. Vilfand V. A. Tishchenko 《Russian Meteorology and Hydrology》2011,36(3):145-154
The probability multimodel forecast system based on the Asia-Pacific Economic Cooperation Climate Center (APCC) model data is verified. The winter and summer seasonal mean fields T 850 and precipitation seasonal totals are estimated. To combine the models into a multimodel ensemble, the probability forecast is calculated for each of single models first, and then these forecasts are combined using the total probability formula. It is shown that the multimodel forecast is considerably more skilful than the single-model forecasts. The forecast quality is higher in the tropics compared to the mid- and high latitudes. The multimodel ensemble temperature forecasts outperform the random and climate forecasts for Northern Eurasia in the above- and below-normal categories. Precipitation forecast is less successful. For winter, the combination of single-model ensembles provides the precipitation forecast skill exceeding that of the random forecast for both Northern Eurasia and European Russia. 相似文献