全文获取类型
收费全文 | 987篇 |
免费 | 20篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 45篇 |
环保管理 | 253篇 |
综合类 | 85篇 |
基础理论 | 254篇 |
污染及防治 | 225篇 |
评价与监测 | 65篇 |
社会与环境 | 33篇 |
灾害及防治 | 14篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 12篇 |
2020年 | 11篇 |
2019年 | 11篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 30篇 |
2015年 | 25篇 |
2014年 | 35篇 |
2013年 | 106篇 |
2012年 | 35篇 |
2011年 | 56篇 |
2010年 | 39篇 |
2009年 | 36篇 |
2008年 | 53篇 |
2007年 | 47篇 |
2006年 | 44篇 |
2005年 | 30篇 |
2004年 | 26篇 |
2003年 | 36篇 |
2002年 | 33篇 |
2001年 | 16篇 |
2000年 | 20篇 |
1999年 | 20篇 |
1998年 | 5篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 15篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 3篇 |
排序方式: 共有1019条查询结果,搜索用时 15 毫秒
891.
892.
Emily Mann Michael A. Long Paul B. Stretesky Margaret Anne Defeyter 《Local Environment》2018,23(10):1008-1022
In response to the problem of holiday hunger, hundreds of local “holiday clubs” have recently been established across the UK. This research examines the spatial relationship between income, childhood deprivation, ethnicity and holiday clubs across 32,844 Lower Super Output Areas (LSOAs) in England to determine if these clubs are currently operating in an inclusive fashion. Data on the location of holiday clubs comes from a national survey. Binary logistic regression results suggest that holiday clubs are likely to operate in economically disadvantaged areas. At the same time, clubs are not distributed equally by ethnicity. That is, holiday clubs operated by voluntary organisations are more likely to be situated in LSOAs that are disproportionately white and English\British and less likely to be situated in LSOAs that are disproportionately ethnic minority. This finding has important implications for the pursuit of holiday clubs as a policy mechanism for addressing access to food in light of the state’s failure to adequately feed all of the country’s children. 相似文献
893.
Douglas Torgerson 《Journal of Environmental Policy & Planning》2018,20(6):781-791
ABSTRACTThe quest for sustainability signals a departure from industrialist presuppositions about the human capacity to control nature that had hardly been questioned during the modern era. Environmental politics, indeed, entered the public scene with warnings of environmental crisis that disrupted industrialist assumptions and supported a call for a dramatic change in course. As environmental problems became part of an agenda of sustainable development, however, there came a shift from a disruptive politics towards professionalization and a managerial emphasis. A reflexive approach to sustainability needs to reconsider the relevance of politics while also thematizing problems of history and power. The concept of ‘developmental constructs’, which Harold D. Lasswell offered as part of his proposal for a reflexive project of contextual mapping, is advanced here as relevant to that end. Comparing the early interventions of Rachel Carson and Amory Lovins to Lasswell's conception of developmental constructs, the article maintains that such proposals for sustainable futures highlight the importance of a political connection. 相似文献
894.
Kitto ME Fielman EM Haines DK Menia TA Bari A 《Journal of environmental radioactivity》2008,99(8):1255-1257
Methods currently approved for the measurement of radon ((222)Rn) in water in New York State are liquid scintillation counting and emanation into alpha-scintillation cells. A passive system using an electret ion chamber (EIC) was evaluated as an alternative for the measurement of radon in water. Over 130 water samples from a community water supply containing 32BqL(-1) and 30 standards containing 686BqL(-1) were measured using the EIC method over 1- to 4-day exposure times. For comparison, identical samples were measured using liquid scintillation counting. Results of duplicate samples were typically within 5% for liquid scintillation counting and within 10% for the EIC. With respect to accuracy, the EIC produced results that were consistently low by 11-15%. 相似文献
895.
The marine toxin, okadaic acid (OA) is produced by dinoflagellates of the genera Prorocentrum and Dinophysis and is the causative agent of the syndrome known as diarrheic shellfish poisoning. In addition, OA acts as both a tumor promoter, attributed to OA-induced inhibition of protein phosphatases as well as an inducer of apoptosis. To better understand the potentially divergent toxicological profile of OA, the concentration-dependent cytotoxicity and alterations in gene expression on the human liver tumor cell line HepG2 upon OA exposure were determined using RNA microarrays, DNA fragmentation, and cell proliferation assays as well as determinations of cell detachment and cell death in different concentrations of OA. mRNA expression was quantified for approximately 15,000 genes. Cell attachment and proliferation were both negatively correlated with OA concentration. Detached cells displayed necrotic DNA signatures but apoptosis also was broadly observed. Data suggest that OA has a concentration dependent effect on cell cycle, which might explain the divergent effects that at low concentration OA stimulates genes involved in the cell cycle and at high concentrations it stimulates apoptosis. 相似文献
896.
Douglas Goudie 《Water, Air, & Soil Pollution: Focus》2009,9(5-6):469-484
Engineering is taking a lead role in sustainability implementation, despite problems linking institutional decision-makers with such things as water purification and cleansing wetlands. An emerging science may help speed an all-system approach to implementing sustainable urban planning. The many innovative approaches to engineering and planning will lead to cities and suburbs where water, urban travel, energy chains and food provision infrastructures are bound together by ESD values, flow-on principles and a workable process of sustainability achievement. JCU Townsville is developing such a process of Sustainability Implementation Planning (SIP) and Engineering, aspiring to become a tropics sustainability exemplar. This article reports on a 90-strong workshop: Paths to Sustainability held in August 2008, with strong regional leadership support. An integrated intellectual frame and ‘futures oriented’ blueprint is provided to achieve the myriad cultural, social, economic, energy, water, food, engineering and environmental needs to ‘go sustainable’ in an urban setting, where most of us live. The workshop results show SIP water management begins with local raindrops, local capture, local ground penetration, use and reuse, entering local nutrient flows to local urban food gardens and then used as a source to grow aquatic protein and fuel oils. Energy engineering becomes a local mix of renewables and innovative storage, appropriate building design, transport systems and industry; including embodied and life-cycle energy analysis and careful considerations in all built structure and use. Urban planning, people movement, housing location and travel mode will increasingly be judged by energy costs, as will food production. 相似文献
897.
Douglas W. Cooper 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1130-1132
Performance of a three-component monostatic Doppler sodar was compared with performance of collocated meteorological tower instruments and evaluated for electric utility applications. The sensors were components of an air pollution monitoring network that was upgraded to assess the impact of coal conversion on ambient air quality at Northeast Utilities' Mt. Tom Generating Station situated in rugged terrain in the Connecticut River valley of western Massachusetts. To determine how well sodar and tower measurements agree, and how reliable sodar is for this type of application, meteorological data and system performance statistics obtained from August 1982 through July 1983 were examined. A statistical comparison of wind speed and direction measurements at 50 m indicated good agreement between the two monitoring techniques. High correlations also were observed for data collected during various weather conditions. System reliability was demonstrated by data recovery rates and sodar vertical range capabilities. Monthly data recovery rates exceeded 90 percent and occasionally approached 98 percent after initial break-in problems were resolved. Sodar range was 100 m more than 95 percent of the time and 200 m more than 50 percent of the time. Under optimum conditions, the vertical range extended beyond 200 m. 相似文献
898.
Douglas S. G. Neufeld 《Environmental monitoring and assessment》2010,168(1-4):385-396
The uptake and seasonal fluctuations of total mercury were followed in caged and uncaged Asiatic clams, Corbicula fluminea, over a 1-year period in South River, Virginia. Mercury was rapidly accumulated in clams transplanted from a nominally uncontaminated site into cages on the contaminated South River, reaching 0.99 μg g???1 dry mass within the first month. Resident clams moved to cages had higher mercury contents after the first month (2.04 μg g???1 dry mass) and at all subsequent times in the study. Large monthly fluctuations in mercury were noted for both resident caged and transplant caged clams with a notable peak occurring in early spring (4.31 μg g???1 dry mass in resident caged clams). Tissue mass of caged clams steadily increased through the winter and early spring. Adjustment of mercury concentrations for tissue mass changes indicated that the changes in mercury contents were primarily due to uptake/release rather than changes in tissue mass (concentration/dilution). The present study demonstrates the utility of using caged Corbicula as mercury biomonitors and illustrates the importance of accounting for large, short-term changes of mercury content in Corbicula when designing long-term biomonitoring studies. 相似文献
899.
Samuel S. Butcher Douglas I. Buckley 《Journal of the Air & Waste Management Association (1995)》2013,63(4):346-348
This paper summarizes the methodology developed to analyze alternative oxidant control strategies of the 1979 Air Quality Plan for the San Francisco Bay Area. The analysis of alternative oxidant control strategies is a complex task, particularly when a grid-based photochemical model is the primary analysis tool. To handle quantitatively spatial and temporal variations in emissions under both existing and projected future conditions, as well as to simulate the effects of a wide variety of control strategies, a system of computer-based models was assembled. The models projected and distributed a number of variables in space and time: population, employment, housing, land use, transportation, emissions, and air quality. Given time and budget constraints, an approach to maximizing the information return from a limited number of model runs was developed. The system was applied in three sequences to determine (1) what future air quality would be if no further controls were implemented, (2) the degree of hydrocarbon and NOx emission control necessary to attain the oxidant standard, and (3) the effectiveness of alternative stationary source, mobile source, transportation and land use control strategies in contributing to attainment and maintenance of the oxidant standard. A number of significant modeling assumptions had to be developed in order properly to interpret the modeled results in the context of the oxidant standard. In particular, a Larsen-type analysis was used to relate modeled atmospheric conditions to “worst case” conditions, and a proportional assumption was made to compensate model results for an imperfect validation. The specification of initial and boundary conditions for future year simulations was found to be a problem in need of further research. 相似文献
900.
Roy V. Rea Kenneth N. Child David P. Spata Douglas MacDonald 《Environmental management》2010,46(1):101-109
Plants cut at different times produce resprouts that vary in their nutritional value relative to when they are cut. To determine
how vegetation management in transportation (road and rail) corridors at different times of the year could influence browse
quality in the years following cutting, and how this could potentially influence encounters between herbivores and vehicles,
we undertook a 3-year study. In 2001, at a wildlife viewing area near Prince George, British Columbia, Canada, we established
a control area and treatment areas where shrubs and trees that are used as food by moose (Alces alces) were cut at the beginning of June, July, August, September, and October. In the fall, moose were most often observed browsing
the resprouts of plants cut in August (years 1 and 2 post-treatment) and September (year 3). Cumulative winter track counts
were highest in the uncut control area in the years following cutting. Spring pellet counts revealed that most pellets were
deposited in the uncut (years 1 and 2) and August-cut (year 3) areas during winter. With the exception of the first year after
cutting, browse removal by moose was highest for plants cut later in the growing season. Overall, our findings suggest that
following cutting, plants cut later in the year are selected more often by moose relative to those cut earlier. To reduce
browse use of corridor vegetation in areas where concerns for moose-vehicle collisions exist, we recommend that vegetation
maintenance activities be conducted in the early summer months of June and July. 相似文献