首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   91247篇
  免费   1233篇
  国内免费   1125篇
安全科学   3845篇
废物处理   3243篇
环保管理   14258篇
综合类   21215篇
基础理论   26470篇
环境理论   78篇
污染及防治   14828篇
评价与监测   5455篇
社会与环境   3658篇
灾害及防治   555篇
  2022年   817篇
  2021年   822篇
  2020年   656篇
  2019年   893篇
  2018年   1144篇
  2017年   1192篇
  2016年   2203篇
  2015年   1835篇
  2014年   2602篇
  2013年   9318篇
  2012年   2227篇
  2011年   2505篇
  2010年   3300篇
  2009年   3417篇
  2008年   2058篇
  2007年   1941篇
  2006年   2328篇
  2005年   2247篇
  2004年   2627篇
  2003年   2425篇
  2002年   1960篇
  2001年   2259篇
  2000年   1982篇
  1999年   1486篇
  1998年   1376篇
  1997年   1359篇
  1996年   1484篇
  1995年   1585篇
  1994年   1490篇
  1993年   1332篇
  1992年   1332篇
  1991年   1298篇
  1990年   1244篇
  1989年   1194篇
  1988年   1048篇
  1987年   986篇
  1986年   994篇
  1985年   1067篇
  1984年   1161篇
  1983年   1175篇
  1982年   1186篇
  1981年   1100篇
  1980年   943篇
  1979年   927篇
  1978年   828篇
  1977年   725篇
  1976年   642篇
  1975年   614篇
  1973年   641篇
  1972年   646篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
731.
Environmental Science and Pollution Research - The Belt and Road Initiative (BRI) is closely linked to the ecological sustainability of the infrastructure ventures that intrinsically include the...  相似文献   
732.
Environmental Science and Pollution Research - Simultaneous achievement of sustainable development goals (SDGs), especially energy efficiency (SDG 7), economic growth (SDG 8), and pollution...  相似文献   
733.
Environmental Science and Pollution Research - The discovery of microRNAs (miRNAs) 20 years ago has advocated a new era of “small molecular genetics.” About 2000 miRNAs are present that...  相似文献   
734.
Environmental Science and Pollution Research - There has been alarming depletion of manganese (Mn) reserves owing to the ongoing extensive mining operations for catering the massive industrial...  相似文献   
735.
The presence of linear alkylbenzene sulfonates (LAS) and their degradation intermediates, sulfophenylcarboxylic acids (SPCs), with concentrations up to 100 ppb has been found in surface waters taken from the estuary of the river Guadalete (Cádiz, SW of Spain). Higher concentrations were found at the sampling site located adjacent to the discharge outlet of a wastewater treatment plant (WWTP). The concentrations decreased downstream to a few ppb as a result of dilution, sorption, and degradation processes, which were taking place along the estuary. Once the presence of both xenobiotics was confirmed in the environment, an in vivo assay was conducted to study their biotransformation and effects in the benthic fish Solea senegalensis. A flow-through system was employed, consisting of an exposure phase (120 h) with environmental levels of the surfactant (200, 500 and 800 microg/L of 2?C(10)LAS), followed by a depuration stage (72 h). The generation of SPCs has been quantified during these phases in both water and fish, with LAS biotransformation shown in all cases. The antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), the phase II enzyme glutathione S-transferase (GST), and the phase III acid and alkaline phosphatases (AcP, ALP) were also estimated and utilized as biomarkers.  相似文献   
736.
Disasters have the potential to act as focusing events, which can increase the amount of attention on disaster‐related problems and encourage policy action. Understanding of the political characteristics of disaster policymaking is underdeveloped, yet it is known that these features may be dissimilar to those of non‐disaster policy areas, especially concerning the coalitions of policy actors engaged in the disaster policy process. Coalitions in the realm of disaster policy processes may be less likely to form, may look very different, and may have different goals than those in non‐disaster domains. Knowledge of the emergence, composition, and purpose of coalitions in disaster policy is lacking. This paper draws on prior theory and case observations to define and describe the characteristics of a disaster policy subsystem and to build a typology of coalitions that may appear within such a subsystem, providing a foundation upon which scholars can work to study coalition dynamics in disaster policy subsystems.  相似文献   
737.
Hypotheses of feeding behaviors and community structure are testable with rare direct evidence of trophic interactions in the fossil record (e.g., bite marks). We present evidence of four predation, scavenging, and/or interspecific fighting events involving two large paracrocodylomorphs (=‘rauisuchians’) from the Upper Triassic Chinle Formation (~220–210 Ma). The larger femur preserves a rare history of interactions with multiple actors prior to and after death of this ~8–9-m individual. A large embedded tooth crown and punctures, all of which display reaction tissue formed through healing, record evidence of a failed attack on this individual. The second paracrocodylomorph femur exhibits four unhealed bite marks, indicating the animal either did not survive the attack or was scavenged soon after death. The combination of character states observed (e.g., morphology of the embedded tooth, ‘D’-shaped punctures, evidence of bicarination of the marking teeth, spacing of potentially serial marks) indicates that large phytosaurs were actors in both cases. Our analysis of these specimens demonstrates phytosaurs targeted large paracrocodylomorphs in these Late Triassic ecosystems. Previous distinctions between ‘aquatic’ and ‘terrestrial’ Late Triassic trophic structures were overly simplistic and built upon mistaken paleoecological assumptions; we show they were intimately connected at the highest trophic levels. Our data also support that size cannot be the sole factor in determining trophic status. Furthermore, these marks provide an opportunity to start exploring the seemingly unbalanced terrestrial ecosystems from the Late Triassic of North America, in which large carnivores far outnumber herbivores in terms of both abundance and diversity.  相似文献   
738.
739.
740.
Trichloroethylene (TCE) is a toxic organic compound, which can adversely affect human health. The chemical is one of the most frequently found contaminants in groundwater in the United States and around the world. A landfill in Maryland contaminated with high levels of TCE decades ago was added to the U.S. Environmental Protection Agency's National Priority List (NPL) in 1994. A biowall was installed on the site in 2013 to promote the bioremediation of TCE and subsequently of its degradation products. Six-year monitoring data indicated a steady removal of >99% groundwater TCE at the wall since installation. However, a concurrent buildup of intermediate byproducts was observed downgradient of the wall. An examination of the entire system was necessary to find the reason behind the inefficiency of the biowall. In this study, the background of the site, remediation plan, and installation were assessed. Monitoring data, including the concentration of TCE and its degradation byproducts, and geochemical and physical characteristics were evaluated to understand the conditions and challenges facing decision-makers of this project and possible options to improve biowall efficacy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号