全文获取类型
收费全文 | 31203篇 |
免费 | 362篇 |
国内免费 | 464篇 |
专业分类
安全科学 | 977篇 |
废物处理 | 1471篇 |
环保管理 | 3857篇 |
综合类 | 5264篇 |
基础理论 | 8125篇 |
环境理论 | 18篇 |
污染及防治 | 8176篇 |
评价与监测 | 2127篇 |
社会与环境 | 1829篇 |
灾害及防治 | 185篇 |
出版年
2023年 | 134篇 |
2022年 | 326篇 |
2021年 | 327篇 |
2020年 | 251篇 |
2019年 | 298篇 |
2018年 | 497篇 |
2017年 | 501篇 |
2016年 | 764篇 |
2015年 | 588篇 |
2014年 | 905篇 |
2013年 | 2484篇 |
2012年 | 1087篇 |
2011年 | 1481篇 |
2010年 | 1192篇 |
2009年 | 1216篇 |
2008年 | 1483篇 |
2007年 | 1532篇 |
2006年 | 1296篇 |
2005年 | 1111篇 |
2004年 | 1000篇 |
2003年 | 1107篇 |
2002年 | 971篇 |
2001年 | 1246篇 |
2000年 | 876篇 |
1999年 | 523篇 |
1998年 | 360篇 |
1997年 | 369篇 |
1996年 | 367篇 |
1995年 | 429篇 |
1994年 | 466篇 |
1993年 | 370篇 |
1992年 | 381篇 |
1991年 | 360篇 |
1990年 | 397篇 |
1989年 | 348篇 |
1988年 | 300篇 |
1987年 | 278篇 |
1986年 | 229篇 |
1985年 | 262篇 |
1984年 | 272篇 |
1983年 | 268篇 |
1982年 | 253篇 |
1981年 | 231篇 |
1980年 | 182篇 |
1979年 | 201篇 |
1978年 | 185篇 |
1975年 | 142篇 |
1974年 | 120篇 |
1972年 | 136篇 |
1971年 | 136篇 |
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
701.
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
702.
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
703.
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
704.
705.
706.
707.
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
708.
709.
Richard E. Jackson Varadarajan Dwarakanath Hans W. Meinardus Carl M. Young 《补救:环境净化治理成本、技术与工艺杂志》2003,13(3):59-66
Recovering dense nonaqueous‐phase liquid (DNAPL) remains one of the most difficult problems facing the remediation industry. Still, the most common method of recovering DNAPL is to physically remove the contaminants using common technologies such as total fluids recovery pumps, vacuum systems, and “pump‐and‐treat.” Increased DNAPL removal can be attained using surfactants to mobilize and/or solubilize the pollutants. However, very little is understood of the methods developed by petroleum engineers beginning in the 1960s to overcome by‐passed, low‐permeability zones in heterogeneous oil reservoirs. By injecting or causing the formation of viscous fluids in the subsurface, petroleum engineers caused increased in‐situ pressures that forced fluid flow into low permeability units as well as the higher permeability thief zones. Polymer flooding involves injecting a viscous aqueous polymer solution into the contaminated aquifer. Foam flooding involves injecting surfactant to decontaminate the high‐permeability zones and then periodic pulses of air to cause a temporary viscous foam to form in the high‐permeable zones after all DNAPL is removed. Later surfactant pulses are directed by the foam into unswept low‐permeable units. These methods have been applied to DNAPL removal using surfactants but they can also be applied to the injection of bio‐amendments into low‐permeability zones still requiring continued remediation. Here we discuss the principles of mobility control as practiced in an alluvial aquifer contaminated with chlorinated solvent and coal tar DNAPLs as well as some field results. © 2003 Wiley Periodicals, Inc. 相似文献
710.
Sadika M. Baladi Catherine M. Lewis Amitava Ganguly Alvin G. Morrow Lisel R. Shoffner Robert F. Blundy Patrick F. Nakagawa Sara T. Mundy Larry Anderson Karen Adams 《补救:环境净化治理成本、技术与工艺杂志》2003,14(1):5-20
Enhanced bioremediation is quickly developing into an economical and viable technology for the remediation of contaminated soils. Until recently, chlorinated organic compounds have proven difficult to bioremediate. Environmentally recalcitrant compounds, such as polychlorinated biphenyls (PCBs) and persistent organic pesticides (POPs) such as dichlorodiphenyl trichloroethane (DDT) have shown to be especially arduous to bioremediate. Recent advances in field‐scale bioremedial applications have indicated that biodegradation of these compounds may be possible. Engineers and scientists at the Savannah River Site (SRS), a major DOE installation near Aiken, South Carolina, are using enhanced bioremediation to remediate soils contaminated with pesticides (DDT and its metabolites, heptachlor epoxide, dieldrin, and endrin) and PCBs. This article reviews the ongoing remediation occurring at the Chemicals, Metals, and Pesticides (CMP) Pits using windrow turners to facilitate microbial degradation of certain pesticides and PCBs. © 2003 Wiley Periodicals, Inc. 相似文献