全文获取类型
收费全文 | 31667篇 |
免费 | 469篇 |
国内免费 | 989篇 |
专业分类
安全科学 | 1072篇 |
废物处理 | 1516篇 |
环保管理 | 3767篇 |
综合类 | 5976篇 |
基础理论 | 8112篇 |
环境理论 | 19篇 |
污染及防治 | 8447篇 |
评价与监测 | 2134篇 |
社会与环境 | 1841篇 |
灾害及防治 | 241篇 |
出版年
2023年 | 183篇 |
2022年 | 426篇 |
2021年 | 393篇 |
2020年 | 324篇 |
2019年 | 331篇 |
2018年 | 551篇 |
2017年 | 567篇 |
2016年 | 825篇 |
2015年 | 659篇 |
2014年 | 989篇 |
2013年 | 2559篇 |
2012年 | 1159篇 |
2011年 | 1527篇 |
2010年 | 1273篇 |
2009年 | 1268篇 |
2008年 | 1531篇 |
2007年 | 1550篇 |
2006年 | 1336篇 |
2005年 | 1138篇 |
2004年 | 1010篇 |
2003年 | 1105篇 |
2002年 | 973篇 |
2001年 | 1261篇 |
2000年 | 900篇 |
1999年 | 564篇 |
1998年 | 374篇 |
1997年 | 383篇 |
1996年 | 384篇 |
1995年 | 447篇 |
1994年 | 469篇 |
1993年 | 369篇 |
1992年 | 385篇 |
1991年 | 365篇 |
1990年 | 391篇 |
1989年 | 346篇 |
1988年 | 300篇 |
1987年 | 281篇 |
1986年 | 225篇 |
1985年 | 248篇 |
1984年 | 265篇 |
1983年 | 257篇 |
1982年 | 243篇 |
1981年 | 223篇 |
1980年 | 175篇 |
1979年 | 194篇 |
1978年 | 176篇 |
1975年 | 140篇 |
1974年 | 117篇 |
1972年 | 130篇 |
1971年 | 131篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Community response to hazard information 总被引:1,自引:0,他引:1
McKay JM 《Disasters》1984,8(2):118-123
The impact of flood hazard information on public acceptance of a selected flood mitigation strategy was assessed by an analysis of the content of newspaper reports of community reaction and letters to the editor. The impact of personal delivery of a flood hazard map on individual perception of risk and attitude to such information was assessed using personal interviews. The results indicated that media coverage of the flood hazard information reduced public criticism of the works. This result must be partially attributable to the dramatic style of media coverage and the fact that the media only emphasized the positive value of the works. The interview demonstrated that personal delivery of the information raised perception of risk, improved comprehension of flood risk, had no impact on acceptability of risk but discouraged some respondents from seeking such information in the future. Factors to explain the last negative change were identified to be the format of the map sheet and low salience of flood hazard. On the basis of all results, methods to improve community response to hazard information are provided. 相似文献
102.
The population dynamics of Mytilicola intestinalis Steuer in mussels (Mytilus edulis L.) from the River Lynher, Cornwall, England, have been studied over 3 years. By transplanting uninfested mussels from the River Erme, South Devon, into the Lynher mussel bed, the study was extended to the growth and development of new infestations under natural conditions. Female Mytilicola intestinalis are shown to breed twice, and two generations of parasites coexist for most of the year, with recruitment taking place in summer and autumn. One generation contributes its first brood to the autumn recruits before overwintering and contributing its second brood to the following summer's recruits. The other generation overwinters as juvenile and immature stages to contribute its two broods successively to the summer and autumn recruits. Environmental temperatures are believed to control the rates of development at all stages rather than acting as triggers in the onset or cessation of breeding at specific times. There is no evidence to support the contention that heavily infested mussels are killed, and parasite mortality is shown to be density-independent. 相似文献
103.
104.
Epidemiological procedures can be organised under disaster conditions by means of a simple surveillance system and with few personnel.
In the aftermath of the 4 February 1976 earthquake in Guatemala, an information system was organized by which the requisite information for decision-making was obtained with adequate speed and promptness.
The initial epidemiologic informution was based on reports collected during the early days on symptoms observed at hospitals and health centers and in localities and villages in the stricken area.
At a second, post-emergency stage a more elaborate surveillance system was instituted to provide guidance in the investigntwn of outbreaks, evaluate the health activities and establish basic criteria for preventive and control measures. 相似文献
In the aftermath of the 4 February 1976 earthquake in Guatemala, an information system was organized by which the requisite information for decision-making was obtained with adequate speed and promptness.
The initial epidemiologic informution was based on reports collected during the early days on symptoms observed at hospitals and health centers and in localities and villages in the stricken area.
At a second, post-emergency stage a more elaborate surveillance system was instituted to provide guidance in the investigntwn of outbreaks, evaluate the health activities and establish basic criteria for preventive and control measures. 相似文献
105.
J.M.R. Hutchinson 《Environment international》1980,3(5):363-364
The development of traceability in low-level radioactivity measurements is discussed. The role that the development of large quantities of natural matrix standards can play is also discussed. 相似文献
106.
Although oil spill cleanup requirements have existed in the United States for years, recent increases in oil imports and marine transportation of petroleum products as well as growing environmental concern have exposed a new industry, the Oil Spill Cleanup Industry. This paper explores some of the microeconomic aspects of this industry which has come under increased scrutiny by the general public, big business, and the federal government.In addition to a brief history and definition, several basic questions about the economic viability of the oil spill cleanup industry are raised and explored, and the impact on the industry of cleanup from government sources is examined, both from the perspective of present operations and from apparent future increases in federal participation. The primary dilemma facing the industry, that of providing continued and immediate supply while confronted with stochastic demand, is discussed. The effects of the large spill on the industry both in terms of revenue and ability to meet cleanup requirements is also considered.Information for the paper is drawn from past and continuing involvement in the U.S. Coast Guard's Marine Environmental Protection Program by both authors. The statistical evidence presented here was compiled through personal interviews and from two computerized Coast Guard information systems; PIRS (the Pollution Incident Reporting System), and SKIM (the Spill Cleanup Equipment Inventory System). 相似文献
107.
108.
109.
This paper describes the help given by the social services department of a shipping company to bereaved families following a shipping disaster. In the absence of clear, factual and prompt information from an authoritative source, there is a tendency for bereaved individuals to deny their loss and thereby delay the process of mourning and eventual recovery. Appropriate intervention and support can help to overcome this tendency as was seen in the Madasa case. 相似文献
110.
Gunavant M. Oza 《The Environmentalist》2003,23(2):189-192
Much of the forest wealth on the plains and in the hilly areas of India has been foolishly destroyed, and the rich heritage of wildlife has been slaughtered mostly for only temporary gain. The wanton axing of the larger indigenous trees and the uprooting of other floristic elements in the hills and on the lower slopes of the mountains, gradually impoverishes them, and may be followed by erosion that ultimately leaves the slopes barren. These alarming threats to the chir (Pinus roxburghii) and fir (Abies pindrow) forests of Kashmir will have disastrous consequences. Once densely-forested, the mountain slopes in Kashmir have become largely naked through too-heavy tapping and cutting of the trees; with concomitant landslides, frequent floods, and loss of fertile topsoil. Unfortunately, the people living in the areas of the chir and fir trees, do not play a proper part in their protection, and the last two decades have witnessed, year by year, the rapid march of urbanization and manifold destructive activities which have taken a heavy toll on these precious species. Urgent conservation measures are essential to preserve these endangered trees in Kashmir. 相似文献