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Courtney G. Flint Amber Spackman Jones Jeffery S. Horsburgh 《Journal of the American Water Resources Association》2017,53(5):988-996
Integrating social and hydrologic sciences for understanding water systems is challenged by data management complexities. Contemporary mandates for open science and data sharing necessitate better understanding of the implications of social science data types. In the context of an interdisciplinary water research program that endeavors to integrate and share social science and biophysical data, we highlight the array of data types and issues associated with social water science. We present a multi‐dimensional classification of social water science data that provides insight into data management considerations for each data type. Recommendations for cyberinfrastructure, planning, and policy are offered. 相似文献
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Seth Payton Greg Lindsey Jeff Wilson John R. Ottensmann Joyce Man 《Journal of Environmental Planning and Management》2008,51(6):717-736
This paper measures the benefits of the urban forest by examining its effect on housing prices. A Geographic Information System is used to develop a measure of the urban forest, the Normalised Difference Vegetation Index, from satellite imagery and to construct other variables from a variety of sources. Spatial hedonic housing price models for the Indianapolis/Marion County area are estimated. The models indicate that greener vegetation around a property has a positive, significant effect on housing price, holding everything else constant. This effect is dominated by measures at the neighborhood level. These findings indicate that property owners value the urban forest, at least in part, by the premium they pay to live in neighborhoods with greener, denser vegetation. These findings also indicate that public action to maintain and enhance the urban forest may be warranted. Planners and urban foresters can use these findings to inform public and policy debates over urban forestry programs and proposals. 相似文献
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Alan S. Kolok Marlo K. Sellin Jeffries Lindsey Knight Daniel D. Snow Shannon L. Bartelt‐Hunt 《Journal of the American Water Resources Association》2014,50(2):266-274
Recent research has suggested that the fate of biologically active compounds (BACs) originating from point sources such as wastewater treatment plants is fundamentally different from that of similar compounds released from nonpoint sources through runoff from agricultural landscapes. Downstream from wastewater treatment plants, BACs will degrade via a variety of mechanisms; however, their concentration in the water adjacent to the point of discharge may not decrease over time, as the compounds are continually released. In contrast, in agricultural systems, BACs are episodically introduced to surface water during snowmelt and rainstorm events, and under these circumstances, may be found in water for only hours or days after a storm event. Recent research in our laboratories as well as others, has suggested that sediments play an important role in the persistence of herbicides and steroids in watersheds after nonpoint source loading events. Conceptually, the sediment serves as both a sink and a source, equilibrating with BACs during storm events then slowly releasing them back into the water over time, long after the initial pulse of chemicals has moved downstream. 相似文献
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When eggs hatch asynchronously, offspring arising from last-hatched eggs often exhibit a competitive disadvantage compared
with their older, larger nestmates. Strong sibling competition might result in a pattern of resource allocation favoring larger
nestlings, but active food allocation towards smaller offspring may compensate for the negative effects of asynchronous hatching.
We examined patterns of resource allocation by green-rumped parrotlet parents to small and large broods under control and
food-supplemented conditions. There was no difference between parents and among brood sizes in visit rate or number of feeds
delivered, although females spent marginally more time in the nest than males. Both male and female parents preferentially
fed offspring that had a higher begging effort than the remainder of the brood. Mean begging levels did not differ between
small and large broods, but smaller offspring begged more than their older nestmates in large broods. Male parents fed small
offspring less often in both brood sizes. Female parents fed offspring evenly in small broods, while in large broods they
fed smaller offspring more frequently, with the exception of the very last hatched individual. These data suggest male parrotlets
exhibit a feeding preference for larger offspring—possibly arising from the outcome of sibling competition—but that females
practice active food allocation, particularly in larger brood sizes. These differential patterns of resource allocation between
the sexes are consistent with other studies of parrots and may reflect some level of female compensation for the limitations
imposed on smaller offspring by hatching asynchrony. 相似文献
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S. Kent Hoekman Amber Broch Curtis Robbins Richard Purcell 《International Journal of Greenhouse Gas Control》2010,4(1):44-50
A laboratory-scale reactor system was built and operated to demonstrate the feasibility of catalytically reacting carbon dioxide (CO2) with renewably-generated hydrogen (H2) to produce methane (CH4) according to the Sabatier reaction: CO2 + 4H2 → CH4 + 2H2O. A cylindrical reaction vessel packed with a commercial methanation catalyst (Haldor Topsøe PK-7R) was used. Renewable H2 produced by electrolysis of water (from solar- and wind-generated electricity) was fed into the reactor along with a custom blend of 2% CO2 in N2, meant to represent a synthetic exhaust mixture. Reaction conditions of temperature, flow rates, and gas mixing ratios were varied to determine optimum performance. The extent of reaction was monitored by real-time measurement of CO2 and CH4. Maximum conversion of CO2 occurred at 300–350 °C. Approximately 60% conversion of CO2 was realized at a space velocity of about 10,000 h?1 with a molar ratio of H2/CO2 of 4/1. Somewhat higher total CO2 conversion was possible by increasing the H2/CO2 ratio, but the most efficient use of available H2 occurs at a lower H2/CO2 ratio. 相似文献