全文获取类型
收费全文 | 3335篇 |
免费 | 248篇 |
国内免费 | 778篇 |
专业分类
安全科学 | 266篇 |
废物处理 | 61篇 |
环保管理 | 747篇 |
综合类 | 1852篇 |
基础理论 | 461篇 |
环境理论 | 3篇 |
污染及防治 | 302篇 |
评价与监测 | 120篇 |
社会与环境 | 402篇 |
灾害及防治 | 147篇 |
出版年
2024年 | 27篇 |
2023年 | 74篇 |
2022年 | 128篇 |
2021年 | 145篇 |
2020年 | 117篇 |
2019年 | 109篇 |
2018年 | 122篇 |
2017年 | 173篇 |
2016年 | 216篇 |
2015年 | 174篇 |
2014年 | 151篇 |
2013年 | 237篇 |
2012年 | 247篇 |
2011年 | 294篇 |
2010年 | 226篇 |
2009年 | 212篇 |
2008年 | 171篇 |
2007年 | 219篇 |
2006年 | 262篇 |
2005年 | 170篇 |
2004年 | 132篇 |
2003年 | 137篇 |
2002年 | 120篇 |
2001年 | 90篇 |
2000年 | 80篇 |
1999年 | 59篇 |
1998年 | 42篇 |
1997年 | 28篇 |
1996年 | 24篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 14篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 12篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1975年 | 6篇 |
1973年 | 6篇 |
1972年 | 3篇 |
1971年 | 6篇 |
排序方式: 共有4361条查询结果,搜索用时 0 毫秒
71.
Transport strategies have been developed for nine European cities to achieve optimum performance in terms of a range of objective functions. The functions selected represent economic efficiency, sustainability and a combination of these. The strategies have been based on combinations of a standard set of policy instruments, including public transport infrastructure, frequency and fares, road capacity increases, low cost road pricing and parking charges. The optimisation method is described, and results presented. The reactions of city authorities to the proposed strategies are discussed and implications for transport policy outlined. 相似文献
72.
Urban ecology is emerging as an integrative science that explores the interactions of people and biodiversity in cities. Interdisciplinary research requires the creation of new tools that allow the investigation of relations between people and biodiversity. It has been established that access to green spaces or nature benefits city dwellers, but the role of species diversity in providing psychological benefits remains poorly studied. We developed a user‐friendly 3‐dimensional computer program (Virtual Garden [ www.tinyurl.com/3DVirtualGarden ]) that allows people to design their own public or private green spaces with 95 biotic and abiotic features. Virtual Garden allows researchers to explore what elements of biodiversity people would like to have in their nearby green spaces while accounting for other functions that people value in urban green spaces. In 2011, 732 participants used our Virtual Garden program to design their ideal small public garden. On average gardens contained 5 different animals, 8 flowers, and 5 woody plant species. Although the mathematical distribution of flower and woody plant richness (i.e., number of species per garden) appeared to be similar to what would be expected by random selection of features, 30% of participants did not place any animal species in their gardens. Among those who placed animals in their gardens, 94% selected colorful species (e.g., ladybug [Coccinella septempunctata], Great Tit [Parus major], and goldfish), 53% selected herptiles or large mammals, and 67% selected non‐native species. Older participants with a higher level of education and participants with a greater concern for nature designed gardens with relatively higher species richness and more native species. If cities are to be planned for the mutual benefit of people and biodiversity and to provide people meaningful experiences with urban nature, it is important to investigate people's relations with biodiversity further. Virtual Garden offers a standardized tool with which to explore these relations in different environments, cultures, and countries. It can also be used by stakeholders (e.g., city planners) to consider people's opinions of local design. Programa de Computadora de Jardín Virtual para Uso en la Exploración de los Elementos de Biodiversidad que la Gente Desea en las Ciudades 相似文献
73.
CHERYL S. BREHME JEFF A. TRACEY LEROY R. MCCLENAGHAN ROBERT N. FISHER 《Conservation biology》2013,27(4):710-720
A primary objective of road ecology is to understand and predict how roads affect connectivity of wildlife populations. Road avoidance behavior can fragment populations, whereas lack of road avoidance can result in high mortality due to wildlife‐vehicle collisions. Many small animal species focus their activities to particular microhabitats within their larger habitat. We sought to assess how different types of roads affect the movement of small vertebrates and to explore whether responses to roads may be predictable on the basis of animal life history or microhabitat preferences preferences. We tracked the movements of fluorescently marked animals at 24 sites distributed among 3 road types: low‐use dirt, low‐use secondary paved, and rural 2‐lane highway. Most data we collected were on the San Diego pocket mouse (Chaetodipus fallax), cactus mouse (Peromyscus eremicus), western fence lizard (Sceloporus occidentalis), orange‐throated whiptail (Aspidoscelis hyperythra), Dulzura kangaroo rat (Dipodomys simulans) (dirt, secondary paved), and deer mouse (Peromyscus maniculatus) (highway only). San Diego pocket mice and cactus mice moved onto dirt roads but not onto a low‐use paved road of similar width or onto the highway, indicating they avoid paved road substrate. Both lizard species moved onto the dirt and secondary paved roads but avoided the rural 2‐lane rural highway, indicating they may avoid noise, vibration, or visual disturbance from a steady flow of traffic. Kangaroo rats did not avoid the dirt or secondary paved roads. Overall, dirt and secondary roads were more permeable to species that prefer to forage or bask in open areas of their habitat, rather than under the cover of rocks or shrubs. However, all study species avoided the rural 2‐lane highway. Our results suggest that microhabitat use preferences and road substrate help predict species responses to low‐use roads, but roads with heavy traffic may deter movement of a much wider range of small animal species. 相似文献
74.
75.
Mohamed El-Hadef El-Okki Leila Sahli Alima Bentellis Radia Azzoug Gijs Du Laing Oualida Rached 《毒物与环境化学》2016,98(1):53-63
Levels of six trace metals were assessed in bank soils of the Rhumel wadi (Northeast Algeria) and their association with soil properties was investigated. Samples were collected at 10 sites. The soils are neutral to moderately alkaline, have high contents of carbonate, and are low in organic carbon and clay. Mean metal concentrations are 1.1 (Cd), 63 (Cr), 20 (Cu), 26 (Ni), 31 (Pb), and 98 (Zn) mg kg?1. The Cd, Cu, Pb, and Zn contents in soil from sites closest to Constantine City were higher than in uncontaminated soils worldwide, indicating accumulation due to human activities (residential, industrial, and agricultural). Statistical analyses (correlation and principal component analysis) demonstrated that Cd, Pb, and Zn are of anthropogenic origin in the urban areas, whereas Cr and Cu enrichment in some situations is caused by industrial activities, while Ni was geogenic. 相似文献
76.
Integrated environmental assessment: an urban perspective 总被引:2,自引:0,他引:2
John Murlis 《环境科学学报(英文版)》1999,11(3):264-271
1 IntroductionUrbanareasthroughouttheworldareincreasinglyafocusofenvironmentalconcern.Theyareplacesofintenseandgrowingeconomicactivity.Inresponse,urbanpopulationsaregrowingrapidly.Itisestimatedthat,by2000,morethanhalftheworld○spopulationwillliveintow… 相似文献
77.
1 IntroductionIntegratedenvironmentalassessment(IEA)isafundamentalmeansforcomprehensiveenvironmentalmanagementandforcoordinatingtherelationshipbetweeneconomicdevelopmentandenvironmentalprotection.IEAaimstoidentifythemainenvironmentalproblemsinaregion… 相似文献
78.
The common language of space: a way of looking at the social,economic and environmental functioning of cities on a common basis 总被引:4,自引:0,他引:4
Bill Hillier 《环境科学学报(英文版)》1999,11(3):344-349
1 SomequestionsandanswersaboutcomplexityThefirstsentenceinanydiscussionaboutthescienceofcitiesusuallycontainstheword“complexity”.Oneofthemostobviousformsthistakesisthesheerphysicalandspatialcomplexityofthecityasanobject.Thereis,however,inmosturbanres… 相似文献
79.
介绍了王台铺矿采用SNP悬浮型填料和先进的水下曝气技术对生活污水进行二级处理,与常规的半软性填料和鼓风曝气方法比较,投资少,成本低,管理方便,曝气均匀,水处理效果好。 相似文献
80.
通过进行大体积露天垃圾堆肥试验,证明大体积鲜垃圾露天单元式堆肥,是在堆温、养分及卫生学等各项指标均达到国家标准的厌氧高温堆肥 相似文献