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51.
We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park,
to help meet the goals of the Natural Resource Challenge—a program to help strengthen natural resource management at national
parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified
information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being
globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for
wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding
aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife.
With these significant natural resources in mind, we also developed a suite of natural resource management recommendations
in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint
for natural resource conservation at publically owned lands. 相似文献
52.
Ming-Der Yang Carolyn J. Merry Robert M. Sykes 《Journal of the American Water Resources Association》1999,35(2):253-263
ABSTRACT: Water quality modeling has been developed for more than three quarters of a century, but is limited to the study of trends instead of making accurate short-term forecasts. A major barrier to water quality forecasting is the lack of an efficient system for water quality monitoring. Traditional water quality sampling is time-consuming, expensive, and can only be taken for small sizes. Remote sensing provides a new technique to monitor water quality repetitively for a large area. The objective of this research is to use remotely sensed data in a water quality model - QUAL2E - in a case study of the Te-Chi Reservoir in Taiwan. The water quality variables developed from the simulations are displayed in map form. The developed forecasting system is designed to predict water quality variables using remote sensing data as an input to initialize and update water quality conditions. 相似文献
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The crystal structure of octachlorodibenzo-p-dioxin (OCDD) was determined and compared with the calculated geometry obtained by the semi-empirical modified neglect of diatomic overlap (MNDO) method. Experimental and calculated geometries for OCDD show excellent agreement. 相似文献
57.
Burton GA Greenberg MS Rowland CD Irvine CA Lavoie DR Brooker JA Moore L Raymer DF McWilliam RA 《Environmental pollution (Barking, Essex : 1987)》2005,134(1):133-144
An in situ toxicity and bioaccumulation assessment approach is described to assess stressor exposure and effects in surface waters (low and high flow), the sediment-water interface, surficial sediments and pore waters (including groundwater upwellings). This approach can be used for exposing species, representing major functional and taxonomic groups. Pimephales promelas, Daphnia magna, Ceriodaphnia dubia, Hyalella azteca, Hyalella sp., Chironomus tentans, Lumbriculus variegatus, Hydra attenuatta, Hexagenia sp. and Baetis tibialis were successfully used to measure effects on survival, growth, feeding, and/or uptake. Stressors identified included chemical toxicants, suspended solids, photo-induced toxicity, indigenous predators, and flow. Responses varied between laboratory and in situ exposures in many cases and were attributed to differing exposure dynamics and sample-processing artifacts. These in situ exposure approaches provide unique assessment information that is complementary to traditional laboratory-based toxicity and bioaccumulation testing and reduce the uncertainties of extrapolating from the laboratory to field responses. 相似文献
58.
Saad F. Tahir Carolyn A. Koh 《Environmental science and pollution research international》1996,3(1):20-23
Bench-scale experiments have been conducted to evaluate a series of titania-supported Pt-Pd (as oxides) catalysts in the presence and absence of MoO3 and Fe2O3 additives for their effectiveness in the complete catalytic oxidation of volatile organic compounds (VOCs) in air likely to be found in waste gases. Under oxidizing conditions, all of the catalysts promoted the complete oxidation of VOCs to CO2 and H2O. 99 % Conversion was achieved with a C2H4-C2H6 gas mixture in air at temperatures between about 160–450 °C and at a space velocity of 20,000 h?1. Oxidation activity for the titania supported catalysts were found to decrease in the order Pt-Pd-Mo-Fe > Pt-Pd-Mo > Pt-Pd-Fe > Pt-Pd. However, the addition of MoO3 and Fe2O3 increase the catalyst activity and reduce the reaction temperature for the complete destruction. Ageing was also performed in order to study the stability of the most active catalyst. Pt-Pd-Mo-Fe (as oxides) on titania catalyst is effective in oxidizing a wide range of volatile organic compounds at relatively low temperatures (220–405 °C) and and at a space velocity of 40,000 h?1 and is resistant to poisoning by halogenated and amine volatile organic compounds. 相似文献
59.
Yin Heliang Sun Tong Yao Lan Jiao Yan Ma Li Lin Lin Graff J Carolyn Aleya Lotfi Postlethwaite Arnold Gu Weikuan Chen Hong 《Environmental science and pollution research international》2021,28(30):40424-40430
Environmental Science and Pollution Research - Currently, 2019-nCoV has spread to most countries of the world. Understanding the environmental factors that affect the spread of the disease COVID-19... 相似文献
60.
Deirdre J. Semeyn Carolyn C. Cush Kerri M. Scolardi Jennifer Hebert Justin D. McBride Denis Grealish John E. Reynolds 《Journal of Coastal Conservation》2011,15(4):573-583
Conservation and management of the endangered Florida manatee is often centered on reducing mortality caused by watercraft
collisions. Lee County, Florida, has led the state in watercraft-related mortality for eight of the last 10 years. This county
is of particular concern as it contains important habitat for manatees, including extensive feeding grounds and an artificial
warm-water refuge where more than 900 manatees have been recorded on a single day. Distributional aerial surveys were conducted
from April 2007 through April 2009 over Lee County waters. Surveys yielded higher numbers of manatees than previously observed
in this area. Using GIS methodology, kernel density analysis illustrated seasonal changes in distribution patterns and highlighted
areas where manatees were most densely clustered. For example, during summer months, manatees were widely distributed throughout
the survey area, with high-density areas associated with seagrass beds. During winter months, manatees were densely clustered
at warm-water sites and over feeding grounds within close distance of these sites. These seasonal distribution patterns coincide
well with speed zone designations. Counts and distributions of manatees were made available, almost immediately if necessary,
to local marine law enforcement in an attempt to focus resources toward reducing manatee-watercraft collisions. Future studies
should implement similar communication strategies to improve conservation efforts. 相似文献