全文获取类型
收费全文 | 833篇 |
免费 | 28篇 |
国内免费 | 81篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 6篇 |
环保管理 | 116篇 |
综合类 | 330篇 |
基础理论 | 55篇 |
污染及防治 | 160篇 |
评价与监测 | 137篇 |
社会与环境 | 58篇 |
灾害及防治 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 24篇 |
2022年 | 13篇 |
2021年 | 16篇 |
2020年 | 22篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 11篇 |
2016年 | 15篇 |
2015年 | 15篇 |
2014年 | 36篇 |
2013年 | 35篇 |
2012年 | 28篇 |
2011年 | 66篇 |
2010年 | 35篇 |
2009年 | 60篇 |
2008年 | 57篇 |
2007年 | 51篇 |
2006年 | 35篇 |
2005年 | 21篇 |
2004年 | 24篇 |
2003年 | 19篇 |
2002年 | 27篇 |
2001年 | 24篇 |
2000年 | 29篇 |
1999年 | 27篇 |
1998年 | 35篇 |
1997年 | 32篇 |
1996年 | 11篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 13篇 |
1992年 | 25篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有942条查询结果,搜索用时 142 毫秒
821.
A regional pollution history has been reconstructed for the borough of Halton (northwest England) from four urban ponds in
north Cheshire and south Merseyside, using environmental analyses of lake sediment stratigraphies. Mineral magnetism, geochemistry
and radiometric dating have produced profiles of pollution characteristics dating from the mid-nineteenth century to present
day. These pollution profiles reflect the atmospheric deposition of a range of pollutants over 150 years of intensified industry.
Distinct phases of pollution deposition and characteristics are identified reflecting: (1) intensification of industry in
the nineteenth century; (2) expansion of industry during the twentieth century; (3) post 1956 Clean Air Acts. This work promotes
the potential use of these pollution archives for use in epidemiology to better understand links between human health and
environmental pollution, especially for diseases with long latency times, where retrospective pollution exposure assessments
are important. 相似文献
822.
823.
成都市大气污染及其防治对策 总被引:1,自引:0,他引:1
本文针对成都市大气污染源进行了探讨,根据可持续发展的原则,提出针对性的解决措施。 相似文献
824.
Charbel Afif Corinne Jambert Vincent Michou Aurélie Colom Gregory Eyglunent Agnès Borbon Véronique Daële Jean-François Doussin Pascal Perros 《环境科学学报(英文版)》2016,28(2):105-113
NitroMAC (French acronym for continuous atmospheric measurements of nitrogenous compounds) is an instrument which has been developed for the semi-continuous measurement of atmospheric nitrous acid (HONO). This instrument relies on wet chemical sampling and detection using high performance liquid chromatography (HPLC)-visible absorption at 540 nm. Sampling proceeds by dissolution of gaseous HONO in a phosphate buffer solution followed by derivatization with sulfanilamide/N-(1-naphthyl)-ethylenediamine. The performance of this instrument was found to be as follows: a detection limit of around 3 ppt with measurement uncertainty of 10% over an analysis time of 10 min. Intercomparison was made between the instrument and a long-path absorption photometer (LOPAP) during two experiments in different environments. First, air was sampled in a smog chamber with concentrations up to 18 ppb of nitrous acid. NitroMAC and LOPAP measurements showed very good agreement. Then, in a second experiment, ambient air with HONO concentrations below 250 ppt was sampled. While NitroMAC showed its capability of measuring HONO in moderate and highly polluted environments, the intercomparison results in ambient air highlighted that corrections must be made for minor interferences when low concentrations are measured. 相似文献
825.
Projecting Canadian Prairie Runoff for 2041–2070 with North American Regional Climate Change Assessment Program (NARCCAP) Data
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jeannine‐Marie St‐Jacques Yuliya Andreichuk David J. Sauchyn Elaine Barrow 《Journal of the American Water Resources Association》2018,54(3):660-675
The South Saskatchewan River Basin (SSRB) of Alberta, Canada, is semiarid and under severe water stress due to increasing human demands. We present the first examination of projected changes in SSRB runoff from a large set of North American Regional Climate Change Assessment Program regional climate models (RCMs) plus one Coordinated Regional Climate Downscaling Experiment RCM. We used six different runoff estimation methods: total surface and subsurface runoff (total runoff), surface runoff, and four estimations based on Budyko functions. Most RCM estimations showed substantial biases and distribution differences when compared to observed data; thus bias correction was necessary. Total runoff was the best of the six variables in modeling observed runoff for each of the four SSRB subbasins. Projected total runoff for 2041–2070 shows a geographic gradient in the SSRB, with possible drying in the southern Oldman River subbasin and possible increased runoff in the northernmost Red Deer River subbasin. A shift to an earlier spring peak in runoff and drier late summer, with a need for increased irrigation, should be expected. In a first examination of the important question of projected changes in interannual variability, we show increasing magnitude. This result further adds to adaptation challenges over the course of this century in this basin, which is already largely closed to further allocation. 相似文献
826.
南京市灰霾期间颗粒物污染的主要影响源识别 总被引:2,自引:0,他引:2
大气颗粒物污染影响范围广,污染种类繁多,污染物形态复杂多变,消除难度较大。随着2014年南京青奥会的日益临近,南京市"蓝天工程"、灰霾污染的控制进入了最关键的阶段。以南京市为例,从宏观微观两方面同时开展研究。在宏观层面上,采用主成分分析、因子分析、相关分析、逐步回归分析等方法,揭示可吸入颗粒物年均浓度、年均降尘量与表征各类影响源变量因素之间的相关关系,并计算贡献率;在微观层面上,采集各影响源尘样,进行相关实验分析得到各影响源特征谱;科学布点采集南京市空气样品,进行相关实验分析得到各点位大气颗粒物样特征谱;采用化学平衡分析法,揭示各粉尘影响源的主要贡献率大小。两方面相结合得到南京市灰霾的主要贡献源为二次扬尘和建筑扬尘,并根据结果提出控制对策。 相似文献
827.
828.
Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy recommendations are given for increasing the regional retention of rafting expenditures and for understanding both the beneficial and adverse impacts that accompany outdoor recreation in rural areas. 相似文献
829.
This paper reports on a nationwide survey of environmental farm plan programmes and plan characteristics, towards determining New Zealand's (NZ's) capability and eligibility for reporting on the Organisation for Economic Cooperation and Development's (OECD) environmental whole farm management plan agri-environmental indicator. Considerations regarding the validity of the indicator are discussed. Environmental farm planning in NZ is widespread, fragmented, and diverse. Nine of NZ's 16 regional authorities have environmental farm plan programmes involving 20 different types of environmental farm plans. Potentially half of NZ's total area of farmland is included, but this is reduced by limited and selective use of environmental farm plans as policy instruments. Three authorities are capable of readily reporting the number and coverage of their environmental farm plans; six would need to manually compile the information. Compliance monitoring is mostly informal, but necessary for checking the implementation of plan works and actions. Eligibility of NZ environmental farm plans cannot be determined until the OECD define acceptance standards. A contemporary definition of environmental farm plans is proposed, along with additional criteria necessary to ensure such plans are credible indicators of issue ownership, adoption of best management practice, and landscape changes intended to improve environmental quality. 相似文献
830.
Toronto is among the fastest-growing urban regions in North America. Regional efforts to preserve rural landscapes and remnant
habitat have had variable success. In the 1990s, significant conflict emerged over proposals to build large housing developments
on portions of the Oak Ridges Moraine, a 160-km stretch of environmentally sensitive land along the city’s northern edge.
After years of planning conflict, Ontario’s provincial government created the Oak Ridges Moraine Conservation Plan, an Act
of the Ontario Legislature. The Plan represents a dramatic change in Ontario’s approach to conservation planning. We examine
the development and implementation of the Conservation Plan as an example of environmental planning policy in a complex urban
setting. Data from interviews with policy actors, planning agency documents, and geospatial sources are used to construct
an analysis and discussion of the Plan and its implementation. From a policy research perspective, the evolution and implementation
of the Plan require analysis and monitoring to better understand how such approaches can best be implemented. The Conservation
Plan marks a change in policy in Ontario, and the implementation process highlights challenges in putting conservation plans
into practice. 相似文献