全文获取类型
收费全文 | 1221篇 |
免费 | 63篇 |
国内免费 | 121篇 |
专业分类
安全科学 | 62篇 |
废物处理 | 16篇 |
环保管理 | 443篇 |
综合类 | 407篇 |
基础理论 | 94篇 |
污染及防治 | 163篇 |
评价与监测 | 118篇 |
社会与环境 | 61篇 |
灾害及防治 | 41篇 |
出版年
2024年 | 9篇 |
2023年 | 16篇 |
2022年 | 26篇 |
2021年 | 41篇 |
2020年 | 47篇 |
2019年 | 28篇 |
2018年 | 27篇 |
2017年 | 43篇 |
2016年 | 60篇 |
2015年 | 42篇 |
2014年 | 62篇 |
2013年 | 56篇 |
2012年 | 66篇 |
2011年 | 110篇 |
2010年 | 52篇 |
2009年 | 92篇 |
2008年 | 93篇 |
2007年 | 78篇 |
2006年 | 72篇 |
2005年 | 37篇 |
2004年 | 38篇 |
2003年 | 36篇 |
2002年 | 34篇 |
2001年 | 26篇 |
2000年 | 27篇 |
1999年 | 23篇 |
1998年 | 15篇 |
1997年 | 23篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 16篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
排序方式: 共有1405条查询结果,搜索用时 46 毫秒
991.
南四湖入湖重点污染河流筛选与水环境问题分析 总被引:4,自引:0,他引:4
根据南四湖主要河流入湖口水质空间分布监测数据,按平均综合污染指数〖WTBX〗Pj〖WTBZ〗>2的标准共筛选出洸府河和薛城小沙河等17条重污染河流,这些河流CODcr、TP、TN的单项污染贡献率平均值依次为455%、763%、86.4%,说明南四湖TN和TP主要来自于重污染河流, CODcr、TP、TN的单项污染分担率平均值依次为22.7%、15.4%、61.9%,说明南四湖的首要入湖污染物是TN,其次是CODcr和TP。给出了南四湖湖东区入湖河口NH3 N与TN的线性回归方程,受湖西与湖东地形地势、河流形态、水力停留时间以及水体中pH、SS、叶绿素a等多种因素的影响,湖西比湖东河流的硝化过程较完全,湖西区和湖东区入湖河口氨氮与总氮的平均比值分别为025和065。分析表明,重污染河流的汇水区域一般都在主要城镇和工矿区分布,CODcr和氮污染物主要来自于工业和城市生活等点污染源,磷污染物主要来自于部分工业行业。因此,加强南四湖流域的工业结构调整、重点企业截污和城市污水处理厂脱氮除磷等点源控制措施仍是重中之重。 相似文献
992.
Lead (Pb) is a toxin that after childhood exposure poses a lifetime of health risks. One route of exposure is soil-Pb as a
result of ∼12 million metric tons of Pb residue in paint and gasoline sold in the US during the 20th Century. Pb accumulated
in soil of the community is a good predictor for blood Pb of children living there. This retrospective study compares the
soil-Pb on Housing Authority of New Orleans (HANO) properties with adjacent private residential (RES) properties within a
0.8 km (0.5 mile) radius. The sample subset (n = 951) is from two soil-Pb surveys (total n = 9,493) conducted between 1989 and 2000. The properties were in both the inner city (CORE) and outlying (OUTER) communities.
The data were analyzed using multi-response permutation procedures (MRPP). The soil-Pb results differ significantly (P-value < 0.001) on same-aged HANO properties at different locations; thus, year of construction does not give adequate explanation
for the soil-Pb differences. HANO and RES soils are significantly more Pb contaminated in the CORE than in OUTER communities
(P-value < 0.001). The CORE has many more years of traffic congestion than OUTER communities; therefore, the lead additives
to gasoline, and not lead-based paint, best elucidate the differences of the soil-Pb footprint at HANO and RES properties
in the CORE and OUTER communites. Currently HANO properties are being redeveloped with cleaner soil, but soil on RES properties
in the CORE of New Orleans remains a large source of Pb (median = 707 mg/kg in this study) for human exposure, especially
children. 相似文献
993.
The danger to health, especially of young children, from lead-bearing particulates in the surface environment is still a valid
concern. Given the multifaceted uses of lead today as well as historically, the sources of lead must be investigated to distinguish
the etiology of lead contamination on the environment. The lead isotope finger printing technique based on isotopic ratio
analyses (IRA) is one of the methods used commonly for provenancing lead sources in environmental studies throughout the world.
This technique, however, has some inherited shortcomings. Therefore, caution must be used in the interpretation of the results,
as this technique can lead to overestimations as well as underestimations of the true source etiology/apportionment of lead
in specific environments. This paper illustrates this with some examples. Data on geographical information systems (GIS) mapping
in urban regions are also presented in this paper. 相似文献
994.
Richard A. McKinney 《Journal of Coastal Conservation》2008,12(4):217-231
Urban coastal wetlands and adjoining coves and embayments can provide habitat for significant numbers of waterbirds, despite
being subject to high levels of stressors from human activities. Yet to date little emphasis has been placed on identifying
these areas and prioritizing them for conservation. In this study I outline a three-step process to identify and prioritize
local sites for conservation using waterbird abundance and diversity and an index of the risk to a site from marine development,
and apply it to a series of urban coastal sites in two North Atlantic estuaries located in the northeast US. By combining
waterbird abundance and species richness with the risk from marine development I generated a ranked list of sites with the
highest listed sites having high bird diversity and low risk from development. From this list individual sites can be prioritized
for conservation, and various protection scenarios can be evaluated and compared. For example, 7 of the top 10 ranked sites
in Boston Harbor, combined with sites already protected under local, state, or federal statutes, represented over half of
the total bird diversity in the Harbor. Similarly, in Narragansett Bay 6 of the top 10 sites when combined with sites already
protected represent 48.8% of the Bay’s bird diversity. Formally protecting these sites, all of which are at relatively low
risk from marine development, could result in the conservation of considerable waterbird habitat at low economic cost (i.e.,
from loss of development potential). Other ranking scenarios (by bird diversity alone, or by risk from marine development)
were also evaluated and compared to the combined ranking. Identification of sites with high bird diversity and low risk from
development could provide important information for local land acquisition groups and planning boards when considering options
for the conservation of urban coastal habitats. 相似文献
995.
Slavica Rajšić Zoran Mijić Mirjana Tasić Mirjana Radenković Jasminka Joksić 《Environmental Chemistry Letters》2008,6(2):95-100
An assessment of air quality of Belgrade, Serbia, was performed by determining the trace element content in airborne daily
PM10 and PM2.5 samples collected from a central urban area. The ambient concentrations of Zn were the highest in PM2.5 (1,998.0 ng m−3). Multivariate receptor modelling (principal component analysis and cluster analysis) has been applied to determine the contribution
of different sources of specific metallic components in airborne particles. The obtained results showed that vehicle traffic
and fossil fuel combustion in stationary objects were the main sources of trace metals in Belgrade urban aerosols. 相似文献
996.
STUART J. MARSDEN 《Environmental management》2000,26(2):207-213
One of the UK's largest flocks of pochard Aythya ferina and tufted duck A. fuligula winters in Manchester's busy dockland redevelopment area. I examined the effects of human disturbance on the population,
and used this information to recommend minimal land-use restrictions that will help ensure the population's continued use
of the site. Birds fed at the docks every night, but on 75% of days, the flock flew to suburban or rural refuges in response
to disturbance. The common causes of disturbance, particularly pedestrians, did not affect the duck greatly, but disturbances
associated with building and redevelopment of the site (e.g., machinery) often made duck evacuate the dock. While birds were
no less likely to evacuate the docks as the winter progressed, they did show some short-term flexibility in their responses
to disturbance. For example, birds appeared able to sit out disturbances throughout the afternoon if they had avoided evacuation
of the docks during the morning. Birds spent only a small proportion of time feeding, and feeding activity was not heightened
following periods of exclusion from the docks due to disturbance. Daytime feeding activity was elevated during periods of
lowering temperatures, and despite heavy disturbance at the site, the impact of disturbance may only be significant during
the coldest period of the winter. During very cold spells, it is important to limit the incidence of unusual disturbances,
such as evening concerts and waterborne activities which tend to make duck evacuate the site. 相似文献
997.
Reconnecting Cities to the Biosphere: Stewardship of Green Infrastructure and Urban Ecosystem Services 总被引:2,自引:0,他引:2
Erik Andersson Stephan Barthel Sara Borgström Johan Colding Thomas Elmqvist Carl Folke Åsa Gren 《Ambio》2014,43(4):445-453
Within-city green infrastructure can offer opportunities and new contexts for people to become stewards of ecosystem services. We analyze cities as social–ecological systems, synthesize the literature, and provide examples from more than 15 years of research in the Stockholm urban region, Sweden. The social–ecological approach spans from investigating ecosystem properties to the social frameworks and personal values that drive and shape human interactions with nature. Key findings demonstrate that urban ecosystem services are generated by social–ecological systems and that local stewards are critically important. However, land-use planning and management seldom account for their role in the generation of urban ecosystem services. While the small scale patchwork of land uses in cities stimulates intense interactions across borders much focus is still on individual patches. The results highlight the importance and complexity of stewardship of urban biodiversity and ecosystem services and of the planning and governance of urban green infrastructure. 相似文献
998.
Contribution of Ecosystem Services to Air Quality and Climate Change Mitigation Policies: The Case of Urban Forests in Barcelona,Spain 总被引:1,自引:0,他引:1
Francesc Baró Lydia Chaparro Erik Gómez-Baggethun Johannes Langemeyer David J. Nowak Jaume Terradas 《Ambio》2014,43(4):466-479
Mounting research highlights the contribution of ecosystem services provided by urban forests to quality of life in cities, yet these services are rarely explicitly considered in environmental policy targets. We quantify regulating services provided by urban forests and evaluate their contribution to comply with policy targets of air quality and climate change mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in biophysical and monetary terms the ecosystem services “air purification,” “global climate regulation,” and the ecosystem disservice “air pollution” associated with biogenic emissions. Our results show that the contribution of urban forests regulating services to abate pollution is substantial in absolute terms, yet modest when compared to overall city levels of air pollution and GHG emissions. We conclude that in order to be effective, green infrastructure-based efforts to offset urban pollution at the municipal level have to be coordinated with territorial policies at broader spatial scales. 相似文献
999.
We review the current state of knowledge about urban ecosystem services in New York City (NYC) and how these services are regulated, planned for, and managed. Focusing on ecosystem services that have presented challenges in NYC—including stormwater quality enhancement and flood control, drinking water quality, food provisioning and recreation—we find that mismatches between the scale of production and scale of management occur where service provision is insufficient. Adequate production of locally produced services and services which are more accessible when produced locally is challenging in the context of dense urban development that is characteristic of NYC. Management approaches are needed to address scale mismatches in the production and consumption of ecosystem services. By coordinating along multiple scales of management and promoting best management practices, urban leaders have an opportunity to ensure that nature and ecosystem processes are protected in cities to support the delivery of fundamental urban ecosystem services. 相似文献
1000.
We explore whether Rotterdam city has the governance capacity in terms of processes at place, and the attention in terms of vision and strategy to take up an integrated approach toward urban resilience. We adopt an interpretative policy analysis approach to assess the dynamics of urban ecosystem governance considering interviews, gray literature, and facilitated dialogues with policy practitioners. We show the inner workings of local government across strategic, operational, tactical, and reflective governance processes about the way urban ecosystems are regulated. Despite the existing capacity to steer such processes, a number of underlying challenges exist: need for coordination between planning departments; need to ease the integration of new policy objectives into established adaptive policy cycles; and need to assess the lessons learnt from pilots and emerging green initiatives. Regulating and provisioning ecosystem services receive heightened policy attention. Focus on regulating services is maintained by a policy renewal cycle that limits and delays consideration of other ecosystem services in policy and planning. 相似文献