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421.
Arabian Journal of Geosciences - The gravimetric geoid model can be used as vertical reference in surveying and other related technologies. It is being developed by NESCOM in collaboration with the... 相似文献
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Theoretical and Applied Climatology - The existing Laspeyres index, Paasche’s index, and Fisher’s index under classical statistics cannot be applied when observations are indeterminate,... 相似文献
424.
We use the f2FF model to study the generation of primordial magnetic fields (PMF) in the context of large field inflation (LFI), described by the potential, V ∼ Mϕp. We compute the magnetic and electric spectra for all possible values of the model parameters under de Sitter and power law expansion. We show that scale invariant PMF are not obtained in LFI to first order in the slow roll approximation, if we impose the constraint V (ϕ = 0) ∼ 0. Alternatively, if these constraints are relaxed, the scale invariant PMF can be generated. The associated electric field energy can fall below the energy density of inflation, ρInf for the ranges of comoving wavenumbers, k > 8 × 10–7 Mpc–1 and k > 4 × 10–6 Mpc–1 in de Sitter and power law (PL) expansion. Further, it can drop below ρInf on the ranges, e‐foldings N > 51, p < 1.66, p > 2.03, l0 > 3 × 105 MPl–1(Hi < 3.3 × 10–6 MPl), and M > 2.8 × 10–3 MPl. All of the above ranges fit with the observational constraints. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
425.
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
426.
Alam Mehtab Jiang Yuan-Jun Umar Muhammad Su Li-jun Rahman Mahfuzur Ullah Faheem 《Acta Geotechnica》2022,17(7):2875-2893
Acta Geotechnica - This paper presents a study in which triaxial tests were performed on loess soil reinforced with natural roots. Triaxial compression tests were performed on soil specimens with... 相似文献
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Wahyudi A’an J. Rahmawati Susi Irawan Andri Hadiyanto Hadiyanto Prayudha Bayu Hafizt Muhammad Afdal Afdal Adi Novi S. Rustam Agustin Hernawan Udhi. E. Rahayu Yusmiana P. Iswari Marindah Y. Supriyadi Indarto H. Solihudin Tubagus Ati Restu Nur Afi Kepel Terry L. Kusumaningtyas Mariska A. Daulat August Salim Hadiwijaya L. Sudirman Nasir Suryono Devi D. Kiswara Wawan 《Ocean Science Journal》2020,55(1):85-97
Ocean Science Journal - Seagrass meadows provide critical ecosystem services for coastal areas, e.g., as nursery habitats for various fish species, help with water filtration of suspended sediment,... 相似文献
429.
Muhammad?ShoaibEmail author Asaad?Y.?Shamseldin Sher?Khan Mudasser?Muneer?Khan Zahid?Mahmood?Khan Bruce?W.?Melville 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(1):155-168
The rainfall–runoff modelling being a stochastic process in nature is dependent on various climatological variables and catchment characteristics and therefore numerous hydrological models have been developed to simulate this complex process. One approach to modelling this complex non-linear rainfall–runoff process is to combine the outputs of various models to get more accurate and reliable results. This multi-model combination approach relies on the fact that various models capture different features of the data, and hence combination of these features would yield better result. This study for the first time presented a novel wavelet based combination approach for estimating combined runoff The simulated daily output (Runoff) of five selected conventional rainfall–runoff models from seven different catchments located in different parts of the world was used in current study for estimating combined runoff for each time period. Five selected rainfall–runoff models used in this study included four data driven models, namely, the simple linear model, the linear perturbation model, the linearly varying variable gain factor model, the constrained linear systems with a single threshold and one conceptual model, namely, the soil moisture accounting and routing model. The multilayer perceptron neural network method was used to develop combined wavelet coupled models to evaluate the effect of wavelet transformation (WT). The performance of the developed wavelet coupled combination models was compared with their counterpart simple combination models developed without WT. It was concluded that the presented wavelet coupled combination approach outperformed the existing approaches of combining different models without applying input WT. The study also recommended that different models in a combination approach should be selected on the basis of their individual performance. 相似文献
430.
Geophysical Investigation of Fresh‐Saline Water Interface: A Case Study from South Punjab,Pakistan
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The importance of the study of fresh‐saline water incursion cannot be over‐emphasized. Borehole techniques have been widely used, but they are quite expensive, intrusive, and time consuming. The electrical resistivity method has proved very successful in groundwater assessment. This advanced technique uses the calculation of Dar‐Zarrouk (D‐Z) parameters, namely longitudinal unit conductance, transverse unit resistance, and longitudinal resistivity has been employed by using 50 vertical electrical sounding points to assess the groundwater and delineate the fresh‐saline water interface over 1045 km2 area of Khanewal in Southern Punjab of Pakistan. The x‐y plots and maps of D‐Z parameters were produced to establish a decipherable vision for the occurrence and distribution of different water‐bearing formations of fresh‐saline water aquifers through a complicated situation of intermixing of different resistivity ranges for fresh‐saline water bodies. This technique is useful to reduce the ambiguity produced by the process of equivalence and suppression which cause intermixing in differentiating fresh, brackish, and saline aquifers during interpretation. The fresh‐saline water interface is correlated very well with the previous studies of water quality analysis carried out in Khanewal area. The results suggest that the D‐Z parameters are useful for demarcating different aquifer zones. The behavior and pattern of D‐Z parameters with respect to occurrence and distribution of different water‐bearing formations were effectively identified and delineated in the study area. 相似文献