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111.
There are two approaches in the application of satellite sensors to marine pollution studies. Satellite sensors are used to observe and characterize ocean pollutants such as industrial wastes and oil. in addition, satellite observations provide information useful in illuminating processes such as eutrophi-cation or air-sea exchange of CO2, that are important in determining the distribution and fate of pollutants. Satellite technology is an important tool in monitoring and studying ocean pollution. Visible sensors have been used to observe and characterize sewage sludge and industrial wastes dumped at sea. Oil slicks have been observed with Landsat, AVHRR and SAR imagery. Besides directly detecting pollutants, satellite sensors are useful for analyzing ocean processes that are influential in the fate of pollutants. These processes include eutrophication of coastal waters and the distribution of suspended matter. the fate of excess CO2 can be addressed using scatterometer-derived estimates of wind speeds to determine the CO2 exchange coefficient at the sea surface on a global scale. 相似文献
112.
Ocean acidification, as a result of increased atmospheric CO2, is predicted to lower the pH of seawater to between pH 7.6 and 7.8 over the next 100 years. The greatest changes are expected
in polar waters. Our research aimed to examine how echinoid larvae are affected by lower pH, and if effects are more pronounced
in polar species. We examined the effects of lowered pH on larvae from tropical (Tripneustes gratilla), temperate (Pseudechinus huttoni, Evechinus chloroticus), and a polar species (Sterechinus neumayeri) in a series of laboratory experiments. Larvae were reared in a range of lower pH seawater (pH 6.0, 6.5, 7.0, 7.5, 7.7, 7.8
and ambient), adjusted by bubbling CO2 gas. The effect of pH on somatic and skeletal growth, calcification index, development and survival were quantified, while
SEM examination of the larval skeleton provided information on the effects of seawater pH on the fine-scale skeletal morphology.
Lowering pH resulted in a decrease in survival in all species, but only below pH 7.0. The size of larvae were reduced at lowered
pH, but the external morphology (shape) was unaffected. Calcification of the larval skeleton was significantly reduced (13.8–36.9%
lower) under lowered pH, with the exception of the Antarctic species, which showed no significant difference. SEM examination
revealed a degradation of the larval skeletons of Pseudechinus and Evechinus when grown in reduced pH. Sterechinus and Tripneustes showed no apparent difference in the skeletal fine structure under lowered pH. The study confirms the need to look beyond
mortality as a single endpoint when considering the effects of ocean acidification that may occur through the 21st century,
and instead, look for a suite of more subtle changes, which may indirectly affect the functioning of larval stages. 相似文献
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J. Durban D. Ellifrit M. Dahlheim J. Waite C. Matkin L. Barrett-Lennard G. Ellis R. Pitman R. LeDuc P. Wade 《Marine Biology》2010,157(7):1591-1604
We used photographic mark-recapture methods to estimate the number of mammal-eating “transient” killer whales using the coastal
waters from the central Gulf of Alaska to the central Aleutian Islands, around breeding rookeries of endangered Steller sea
lions. We identified 154 individual killer whales from 6,489 photographs collected between July 2001 and August 2003. A Bayesian
mixture model estimated seven distinct clusters (95% probability interval = 7–10) of individuals that were differentially
covered by 14 boat-based surveys exhibiting varying degrees of association in space and time. Markov Chain Monte Carlo methods
were used to sample identification probabilities across the distribution of clusters to estimate a total of 345 identified
and undetected whales (95% probability interval = 255–487). Estimates of covariance between surveys, in terms of their coverage
of these clusters, indicated spatial population structure and seasonal movements from these near-shore waters, suggesting
spatial and temporal variation in the predation pressure on coastal marine mammals. 相似文献
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As the nations of the world negotiate future controls on greenhouse gas emissions, a critical environmental policy issue becomes
understanding the multiple environmental consequences of these controls. Here we describe an integrated assessment model for
quantifying multiple environmental impacts of large-scale environmental initiatives and apply this model to climate change
mitigation. Our analysis shows that reductions in global warming will be accompanied by reductions in ozone depletion, acid
rain and mercury emissions, and desulfurization waste generation. We also conclude that the largest collateral benefits from
reducing global climate change may be in the developing world. This result is critical since it is the developing nations
who ultimately control the long-term success of any climate stabilization strategy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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This paper outlines some of the potential uses of GIS in planning authorities, and identifies some of the pitfalls to be avoided. It begins with some practical considerations in the area of data sources and system configurations, goes on to envision ways in which GIS might benefit the work of a planning department, and finally considers some of the management issues which surround the introduction and use of GIS in planning. 相似文献