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   1228篇
  免费   19篇
  国内免费   10篇
安全科学   39篇
废物处理   43篇
环保管理   230篇
综合类   136篇
基础理论   366篇
环境理论   1篇
污染及防治   285篇
评价与监测   79篇
社会与环境   71篇
灾害及防治   7篇
  2023年   28篇
  2022年   33篇
  2021年   16篇
  2020年   13篇
  2019年   33篇
  2018年   24篇
  2017年   36篇
  2016年   42篇
  2015年   32篇
  2014年   48篇
  2013年   96篇
  2012年   41篇
  2011年   94篇
  2010年   70篇
  2009年   52篇
  2008年   54篇
  2007年   65篇
  2006年   71篇
  2005年   44篇
  2004年   39篇
  2003年   46篇
  2002年   42篇
  2001年   28篇
  2000年   13篇
  1999年   6篇
  1998年   14篇
  1997年   22篇
  1996年   18篇
  1995年   8篇
  1994年   15篇
  1993年   7篇
  1992年   8篇
  1991年   6篇
  1990年   7篇
  1989年   8篇
  1988年   10篇
  1987年   4篇
  1986年   4篇
  1985年   2篇
  1984年   5篇
  1983年   5篇
  1982年   6篇
  1981年   4篇
  1980年   5篇
  1979年   8篇
  1978年   6篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1965年   2篇
排序方式: 共有1257条查询结果,搜索用时 15 毫秒
161.
162.
Environmental Chemistry Letters - Nanoplastics are probably much more dangerous for living organisms than microplastics because they are more abundant and reactive. They can potentially...  相似文献   
163.
The carbamazepine (CBZ) abatement is herein evaluated using catalytic ozonation at different NiO concentrations as catalyst: 100, 300, and 500 mg   相似文献   
164.
165.
166.
Despite women's advancements in the workplace, gender inequality persists. We classify and test two frameworks used to explain gender differences in career success: unequal attributes and unequal effects. The unequal attributes framework suggests that gender is related to other attributes, which result in unequal career outcomes for men and women (i.e., a mediated effect). The unequal effects framework suggests that even when men and women share the same attribute or circumstances, they are rewarded differently, such that individual attributes have unequal effects on career outcomes for men and women (i.e., a moderated effect). We collected survey data from a gender‐balanced sample of 394 business school alumni. Using structural equation modeling to test the unequal attributes framework, we found that work hours, career orientation, having a nonemployed spouse, and working in a predominantly female job were unequal attributes that explained gender differences in career success. Using multigroup path analysis to examine unequal effects, we found that being agentic, married, having children at home, and working in a predominantly female workplace had unequal effects in relation to career success for men and women. We find support for both models across three categories of career success antecedents (i.e., personal, family, and job attributes).  相似文献   
167.
Growth of individually marked specimens of Notoacmea scutum (Rathke) was followed for 15 months (April, 1978 to June, 1979) at a field site in central California, USA. Growth rates were highly seasonal, being highest from late spring through early summer and lowest during winter. Growth rate also varied significantly with intertidal height: limpets lower in the intertidal zone grew faster. Both relationships may have been related to the relative abundance of food or to the amount of time available for foraging. Recently settled limpets, which were present throughout the year, grew to approximately 17 mm in length by the end of their first year; by then, they had also reached the size at which mature gonads were consistently found (16 mm). Limpets were almost 26 mm long by the end of the second year. Substantial mortality occurred throughout the year, but it was particularly severe during winter, when a large portion of the reproductive population was lost. This pronounced winter mortality was probably not caused by invertebrate predators such as seastars. Most limpets at the study site were less than 2 yr old.  相似文献   
168.
An urgent need for a sub-tropical and tropical indicator organism for use in the biological monitoring of pollutants is recognised. To this end, preliminary studies have been undertaken to test the indicator ability of the rock oyster Saccostrea glomerata (=Crassostrea glomerata Gould) for monitoring the trace metals cadmium, copper, iron and zinc. A survey of these trace metals in rock oysters from 54 sites in Hong Kong waters revealed elevated levels of metals in several areas. Profiles of metal abundance in S. glomerata agreed substantially with the distribution of industrial and domestic discharges in Hong Kong, and also with patterns of contamination found in studies of the Pacific oyster Crassostrea gigas and of sediments. Application of POLYDIV statistical analysis to these data has aided their interpretation and confirmed the relationship between known areas of contamination and elevated metal levels in S. glomerata. This oyster, which exhibits an unusually great capacity to accumulate a range of elements from the ambient environment, thus appears to be a reliable indicator organism, and may be of great value in global monitoring studies.  相似文献   
169.
Grey dunes are a priority habitat type of the European Union Habitats Directive and demand special attention for conservation and management. Knowledge of the ecology of coastal grey dunes can contribute to this policy. Dune grassland succession is initiated by fixation and driven by the complex of soil formation (humus accumulation) and vegetation development. Leaching and mobilization of CaCO3. which are important in nutrient dynamics, complicate the picture. At present, grass- and scrub encroachment greatly overrules these fine scaled soil processes and causes substantial loss of regional biodiversity. Belgium has an international responsibility in grey dune conservation because of the limited range of its characteristic vegetation, flora and fauna. As biomass removal seems essential in grassland preservation, grazing is an important management tool. Evaluation of management measures focuses on biodiversity measurements on the levels of landscape, community and species.  相似文献   
170.
When choosing between two potential mates, a male may benefit by picking a larger (longer and/or more heavy-bodied) female because she is likely to produce more or larger offspring. Males of many species use visual cues to evaluate the sizes of their mates, but in some situations (at night or in a crowded mating swarm), vision may be useless. Potentially, males may be able to use chemical cues that convey information about female body size. We manipulated cues available to free-ranging male garter snakes (Thamnophis sirtalis parietalis) in large courting aggregations near communal dens in Manitoba, Canada. Males not only directed disproportionate courtship to longer and heavier-bodied females, but also courted most vigorously in response to lipids extracted from the skins of such females. Our data show that with a flick of his tongue, a male garter snake can identify not only a female's body length, but also her body condition.  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