全文获取类型
收费全文 | 126篇 |
免费 | 4篇 |
国内免费 | 4篇 |
专业分类
废物处理 | 3篇 |
环保管理 | 65篇 |
综合类 | 23篇 |
基础理论 | 10篇 |
污染及防治 | 11篇 |
评价与监测 | 12篇 |
社会与环境 | 9篇 |
灾害及防治 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2013年 | 8篇 |
2012年 | 1篇 |
2011年 | 9篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有134条查询结果,搜索用时 15 毫秒
81.
Many government agencies and other organizations sample natural alpine and subalpine surface waters using varying protocols
for sample storage and filtration. Simplification of protocols would be beneficial if it could be shown that sample quality
is unaffected. In this study, samples collected from low ionic strength waters in alpine and subalpine lake inlets and outlets
in the western United States were used to evaluate (1) effects of refrigerated storage time on the chemistry of unfiltered
samples, and (2) differences in sample filtration protocols. No analytes exhibited significant changes when stored less than
48 h. Six analytes (pH, sodium, ammonium, potassium, chloride, sulfate) exhibited statistically significant (but small) changes
when storage time exceeded 48 h. Two analytes (calcium, nitrate) were significantly higher when samples were field filtered
than when filtered in the laboratory, but the differences were also small. For waters similar to those in this test, unfiltered
refrigerated samples may be stored up to 48 h without compromising sample quality. The small differences between field and
lab filtration do not justify the expense, training, and contamination risk of field filtration. 相似文献
82.
Ecotechnological methods have been employed by developed countries like the United States of America, Europe, Australia and
Japan in the restoration of their degraded freshwater ecosystems. These methods according to literature sources, in many cases
have produced the desired results in these countries where they have been implemented. This article is aimed at providing
an overview on aspects of available ecotechnological methods employed in the reduction of eutrophication and acidification
and in Lake Ecosystem restoration in general. Ecotechnological methods offer great opportunities for developing countries
with tropical or subtropical climates due to their cost-effectiveness. The efficacy and potential limitations of the various
methods in their respective restorative approach is also reported in this article. 相似文献
83.
Climate change is likely to impact terrestrial and aquatic ecosystems via numerous physical and biological mechanisms. This study outlines a framework for projecting potential impacts of climate change on lakes using linked environmental models. Impacts of climate drivers on catchment hydrology and thermal balance in Onondaga Lake (New York State) are simulated using mechanistic models HSPF and UFILS4. Outputs from these models are fed into a lake ecosystem model, developed in AQUATOX. Watershed simulations project increases in the magnitude of peak flows and consequent increases in catchment nutrient export as the magnitude of extreme precipitation events increases. This occurs concurrently with a decrease in annual stream discharge as a result of increased evapotranspiration. Simulated lake water temperatures increase by as much as 5 °C during the 2040-2069 time period, accompanied by a prolonging of the duration of summer stratification. Projected changes include shifts in the timing of nutrient cycling between lake sediments and water column. Plankton taxa projected to thrive under climate change include green algae and Bosmina longirostris. Responses for species at higher trophic levels are mixed. Benthic macroinvertebrates may either prosper (zebra mussels) or decline (chironomids), while fish (e.g., gizzard shad) exhibit high seasonal variability without any clear trend. 相似文献
84.
The International Joint Commission's Water Quality Board has identified 42 Areas of Concern in the Great Lakes ecosystem where Great Lakes Water Quality Agreement objectives or jurisdictional standards, criteria or guidelines, established to protect uses, have been exceeded and remedial actions are necessary to restore beneficial uses. As a result of the 1985 report of the Water Quality Board, the eight Great Lakes states and the Province of Ontario committed themselves to developing a remedial action plan (RAP) to restore all uses in each Area of Concern within their political boundaries. Each RAP must identify the specific measures necessary to control existing sources of pollution, abate existing contamination (e.g., contaminated sediments), and restore all beneficial uses. Points which must be explicitly addressed in each RAP include: geographic extent of problem, beneficial uses impaired, causes of problems, remedial measures and a schedule for implementation, responsible agencies, and surveillance and monitoring activities that will be used to track effectiveness of remedial actions. The jurisdictions are responsible for developing RAPs, and the International Joint Commission is responsible for evaluating the adequacy of each RAP and tracking progress in restoring beneficial uses. 相似文献
85.
Sigurd Rognerud Vladimir A. Dauvalter Eirik Fjeld Brit Lisa Skjelkvåle Guttorm Christensen Nickolay Kashulin 《Ambio》2013,42(6):724-736
A large copper–nickel smelter complex is located at the Kole Penninsula, Russia, close to the Norwegian border. Trace-element concentrations in surface sediments (0–0.5 cm) and pre-industrial sediments from 45 lakes in the region were used to uncover spatial deposition patterns and contamination factor of sediments. Elevated concentrations were found, especially for Ni and Cu, but also for Pb, Co, Hg, As, and Cd. Highest concentrations were found up to 20 km from the smelter, but the concentrations decreased exponentially with distance from the smelter. Increasing Ni, Cu, As, and Hg concentrations from sub-surface to surface sediments were found for lakes at intermediate distances (20–60 km). This may reflect recent changes in atmospheric depositions, as shown in nearby Norwegian areas. However, we cannot rule out that this also may have been caused by diagenetic processes, especially for the most redox-sensitive elements such as As. 相似文献
86.
Anna C. Hurlimann 《The Environmentalist》2007,27(1):83-94
The emergence of a global water crisis has seen the necessity for a sustainable approach to water management. Policies directed
towards water recycling have been implemented in many regions of the world. In Australia, prolonged drought conditions in
most major cities during the past decade have led to serious national calls for less drinking water to be used (Prime Minister’s
Science Engineering and Innovation Council, 2003), and a strategic policy response from many State Governments, including
bold targets for water recycling. A key consideration to the realisation of these policies is greater understanding of community
attitudes to recycled water use, without which, a number of recycled water projects have failed (Hurlimann and McKay, 2004).
Despite the critical nature of community attitudes, little research has been conducted, especially in relation to perception
of risk, which has been found to be critical in the adoption of new technologies (Cvetkovich and Lofstedt, 1999). This paper
investigates an urban Australian community’s perception of risk involved with using recycled water. Key findings include:
perception of risk increased as the use of recycled water became increasingly personal. Perception of risk was significantly
negatively related to trust, perception of fairness and information. Trust in the Water Authority to manage risk was significantly
related to perception of trust, communication and integrity of the Authority. 相似文献
87.
Nancy A. Connelly Tommy L. Brown Jonathan W. Brown 《Journal of the American Water Resources Association》2007,43(4):1016-1023
Abstract: The purpose of this article was to show how the value of recreational boating can be assessed and how that value can be linked to water levels. Data were gathered via a survey of recreational boaters to determine days boated and willingness‐to‐pay (net economic value) for boating on Lake Ontario and on the St. Lawrence River in 2002. Depth measurements were taken at marinas and yacht clubs, boat launch ramps, and private docks. Stage‐damage curves were used to pinpoint at what water levels and to what extent boaters would be impacted. Boaters recreated an estimated 1.3 million days in 2002 and spent an estimated US$178 million in New York counties bordering Lake Ontario and the St. Lawrence River. The mean net economic value per day per boat (above current expenditures) was $69.36, with an estimated total net economic value of US$90 million. Using Lake Ontario as an example, the stage‐damage curves show that the overall negative impact would be small, between 245 and 248 ft. Maintaining water levels within that range for the entire boating season would be ideal for Lake Ontario boaters and associated businesses. 相似文献
88.
Trick Charles G. Creed Irena F. Henry Michael F. Jeffries Dean S. 《Water, Air, & Soil Pollution: Focus》2002,2(1):103-128
We explored the spatial variation in diatom communities withinthe Turkey Lakes Watershed (TLW). The TLW is a single watershed in an old growth sugar maple forest that contains an alternatingseries of stream and lake embayments. Near the outlet of each lake, we sampled pools and riffles to determine abundance and diversity of diatom communities along this hydrologic system. Diatom diversity, measured by Shannon-Weaver Index, richness andevenness, increased steadily downstream before eventually decreasing near the watershed outlet. Canonical CorrespondenceAnalysis indicated that diatom genera were correlated with streamchemistry. Upper reaches were the least productive, characterizedby lower pH (<7), higher N:P (113:1 to 124:1, dominated by complex forms of N), and high mean relative abundances of Eunotia spp., Tabellaria spp., and Pinnularia spp. Middle and lower reaches were more productive, characterized byhigher pH (>7), lower N:P (71:1 to 90:1, dominated by simple forms of N, e.g., nitrate-N), and high mean relative abundances of Cymbella spp. and Brachysira spp. Achnanthesminutissima (Kutz.) Hustedt, the most abundant species, and Navicula spp., Nitzschia spp., Gomphonema spp., and Frustrulia spp. were represented at all stream sites. Thisstudy revealed that within the TLW, a hydrologic system of the same stream order, the diatom community was influenced by a nutrient gradient, where the stream and its intervening lakes contributed to a shift from acidic, inorganic N-poor upper reaches to a circum-neutral, inorganic N-richer outlet. By imparting genera-specific stresses, stream flow (i.e. pools vs. riffles) further shaped the diatom community. 相似文献
89.
Robert E. Deyle 《Journal of the American Water Resources Association》1995,31(3):387-398
ABSTRACT: Water management in the United States has historically been characterized by a decisionmaking system that is fragmented along three dimensions: (1) physical, (2) institutional, and (3) political-technical. The result is often ‘garbage can’ decision-making in open decisionmaking structures with the attributes of an ‘organized anarchy’ rather than the rational, comprehensive decisionmaking prescribed for water management. A case study of water quality management decisionmaking in the New York Finger Lakes is used to illustrate how the garbage can model can illuminate the forces that operate in fragmented water management. Interorganizational decisionmaking theory and experience from water management integration initiatives are then applied to assess what strategies may be effective in reducing the organizational anarchy that results from fragmented water management institutions. 相似文献
90.
S. J. Bolsenga 《Journal of the American Water Resources Association》1976,12(1):147-156
ABSTRACT. Data from seven vessel cruises from late May to early November permitted definition of the surface water temperature regime of Lake Huron on a monthly basis. Quantitative values are furnished for a portion of the warming, stable, and cooling periods. The lowest temperatures occurred near the center of the lake, southwest of Manitoulin Island, and at De Tour Passage. The highest temperatures occurred at the mouth of Saginaw Bay and in the southernmost portions of the lake. Comparison of the surface water temperatures with temperatures in the 21 - 30 m layer shows the heat storage lag characteristic of large lakes. 相似文献