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151.
Leandra Cho 《Ocean & Coastal Management》2005,48(11-12):932
Management of the Belize Barrier Reef was originally envisioned through the creation of marine protected areas. However, the influence of land-based activities was not accounted for in Marine Protected Area (MPA) programs. Therefore focus was shifted to an integrated approach via Integrated Coastal Management (ICM). The Belize ICM process has evolved into a system of coordination through the fostering of multi-sectoral linkages for integrated management of coastal resources. Marine protected areas were included in the ICM program as tools for achieving biodiversity protection and management of sensitive habitats. The ICM process has resulted in greater coordination and consultation in decision making for coastal resource issues, the MPA program however has not evolved with the trend of greater community involvement in MPA management. The greatest challenges to MPA and ICM programs in the next 10 years are: improved linkages between the two, fostering of community participation in management, broadening of the scope of ICM to watersheds and ocean governance, and sustainable financing for both programs. 相似文献
152.
The process of embryogenesis and larval development of the asteroid sea star Asterias amurensis (Lütken) was observed, with
special attention paid to morphological change and larval duration. In reproductive season, mature sea stars were collected
under floating net cages, located in Tongyeong, southern Korea. The mature eggs are 138 μm in average diameter, semi-translucent
and orange in color, sperms in good condition appear light cream to white-gray in color. Embryos develop through the holoblastic
equal cleavage stage and a wrinkled blastula stage that lasts about 9 hours after fertilization. Gastrulae bearing an expanded
archenteron hatch from the fertilization envelope 22 hours after fertilization. At the end of gastrulation, rudiments of the
left and right coelom are formed. By day 2, larvae possess complete alimentary canal and begin to feed. At this stage, the
larva is called early bipinnaria. In 6day-old larvae, the pre- and post- oral ciliated bands form complete circuits and the
bipinnarial processes start to develop. By day 12, the lateral and anterior projection of the larval wall processes along
the ciliated bands begins to thicken and curl, and the ciliated bands become more prominent. By day 32, early brachiolaria
are presented with three pairs of brachiolar arms. Advanced brachiolaria with a well-developed brachiolar complex (three pairs
of brachia and central adhesive disc) occur 6 weeks after fertilization. In the field, spawning of the sea star was observed
in April to May, settlement form larvae and just settlements seem to occur from June to July, and early juveniles occur from
August to September. Although we had not described the end of brachiolaria stage, it can be tentatively estimated that the
duration of the pelagic stage of A. amurensis is 40 to 50 days. 相似文献
153.
154.
The Saemanguem Reclamation Project proposed building a 33 km dike, to reclaim 28,300 ha of wetlands and estuary for rice production. In addition, the project would store 530 million tons of freshwater in the estuary for agriculture. The time frame for this construction was 21 years from 1991 to 2011 with a budget of US $2.1 billion. During the project, another reclamation project, called the “Shiwha Reclamation Project,” which was established between 1987 and 1994, was written off as a failure and an environmental disaster. The public started to recognize the value of wetlands and coastal waters and has strongly opposed the Saemanguem Reclamation Project. However, the voices of supporters for the project were also strong, so its resolution was controversial. This article analyzes the evolution and solution of conflicts among stakeholders and discusses some lessons applicable to large reclamation projects. 相似文献
155.
A numerical model describing the propagation and run-up process of nearshore tsunamis in the vicinity of shorelines is developed based on an approximate Riemann solver. The governing equations of the model are the nonlinear shallow-water equations. The governing equations are discretized explicitly by using a finite volume method. The nonlinear terms in the momentum equations are solved with the Harten-Lax-van Leer-Contact (HLLC) approximate Riemann solver. The developed model is first applied to prediction of water motions in a parabolic basin, and propagation and subsequent run-up process of nearshore tsunamis around a circular island. Computed results are then compared with available analytical solutions and laboratory measurements. Very reasonable agreements are observed. 相似文献
156.
In this paper, image processing technique that reduces video images of buoy motion to yield time series of image coordinates
of buoy objects will be investigated. The buoy motion images are noisy due to time-varying brightness as well as non-uniform
background illumination. The occurrence of boats, wakes, and wind-induced white caps interferes significantly in recognition
of buoy objects. Thus, semiautomated procedures consisting of object recognition and image measurement aspects will be conducted.
These offer more satisfactory results than a manual process. Spectral analysis shows that the image coordinates of buoy objects
represent wave motion well, indicating its usefulness in the analysis of wave characteristics. 相似文献
157.
ABSTRACTA hybrid hydrologic model (Distributed-Clark), which is a lumped conceptual and distributed feature model, was developed based on the combined concept of Clark’s unit hydrograph and its spatial decomposition methods, incorporating refined spatially variable flow dynamics to implement hydrological simulation for spatially distributed rainfall–runoff flow. In Distributed-Clark, the Soil Conservation Service (SCS) curve number method is utilized to estimate spatially distributed runoff depth and a set of separated unit hydrographs is used for runoff routing to obtain a direct runoff flow hydrograph. Case studies (four watersheds in the central part of the USA) using spatially distributed (Thiessen polygon-based) rainfall data of storm events were used to evaluate the model performance. Results demonstrate relatively good fit to observed streamflow, with a Nash-Sutcliffe efficiency (ENS) of 0.84 and coefficient of determination (R2) of 0.86, as well as a better fit in comparison with outputs of spatially averaged rainfall data simulations for two models including HEC-HMS. 相似文献
158.
Abstract In this paper, we introduce the cyclostationary processes into climate analysis and undertake a systematic study of the cyclic spectra of surface temperature fluctuations. The technique is adapted from cyclostationarity theory in signal processing. To demonstrate the usefulness of this technique, a very simple cyclostationary stochastic climate model is constructed. Our results show that the seasonal cycle strongly modulates the amplitudes of the covariance and the spectrum. The technique was also applied to the surface temperature fluctuations in a fifteen‐year seasonal run of the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM2, R15) using a zonally symmetric all‐land surface as the lower boundary. The results indicate that intraseasonal oscillations localized according to time of year are still present even after the surface temperature fields have been normalized using the commonly used procedure. Both examples suggest that the “annual cycle” cannot be “removed” by simply using a normalization procedure. The climate is not as completely represented when modelled as stationary processes. 相似文献
159.
The effects of variability in climate and watershed (groundwater withdrawal and land use) on dry‐weather streamflows were investigated using SWAT (Soil and Water Assessment Tool). The equation to predict the total runoff (TR) using climate data was derived from simulation results for 30 years by multiple regression analysis. These may be used to estimate effects of various climate variations (precipitation during the dry period, precipitation during the previous wet period, solar radiation, and maximum temperature). For example, if daily average maximum temperature increases by 3 °C, TR during the dry period will decrease by 27·9%. Similarly, groundwater withdrawals strongly affect streamflow during the dry period. However, land use changes (increasing urbanization) within the forested watershed do not appear to significantly affect TR during the dry period. Finally, a combined equation was derived that describes the relationships between the TR during the dry period and the climate, groundwater withdrawal and urban area proportion in a small monsoon watershed. This equation will be effective to predict the water availability during the dry periods in the future since it is closely related to changes of temperature, precipitation, solar radiation, urban area ratio, and groundwater withdrawal quantity. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
160.
Building period formulas in seismic design code are evaluated with over 800 apparent building periods from 191 building stations and 67 earthquake events. The evaluation is carried out with the formulas in ASCE 7‐05 for steel and RC moment‐resisting frames, shear wall buildings, braced frames, and other structural types. Qualitative comparison of measured periods and periods calculated from the code formulas shows that the formula for steel moment‐resisting frames generally predicts well the lower bound of the measured periods for all building heights. But the differences between the periods from code formula and measured periods of low‐ to‐medium rise buildings are relatively high. In addition, the periods of essential buildings designed with the importance factor are about 40% shorter than the periods of non‐essential buildings. The code formula for RC moment‐resisting frames describes well the lower bound of measured periods. The formula for braced frames accurately predicts the lower bound periods of low‐to‐medium rise buildings. The formula for shear wall buildings overestimates periods for all building heights. For buildings that are classified as other structural types, the measured building periods can be much shorter than the periods calculated with the code formula. Based on these observations, it is suggested to use Cr factor of 0.015 for shear walls and other structural types. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献