全文获取类型
收费全文 | 18092篇 |
免费 | 188篇 |
国内免费 | 205篇 |
专业分类
安全科学 | 585篇 |
废物处理 | 735篇 |
环保管理 | 2333篇 |
综合类 | 3684篇 |
基础理论 | 4279篇 |
环境理论 | 9篇 |
污染及防治 | 4458篇 |
评价与监测 | 1387篇 |
社会与环境 | 915篇 |
灾害及防治 | 100篇 |
出版年
2022年 | 164篇 |
2021年 | 148篇 |
2020年 | 133篇 |
2019年 | 164篇 |
2018年 | 273篇 |
2017年 | 317篇 |
2016年 | 434篇 |
2015年 | 330篇 |
2014年 | 522篇 |
2013年 | 1358篇 |
2012年 | 613篇 |
2011年 | 798篇 |
2010年 | 641篇 |
2009年 | 712篇 |
2008年 | 754篇 |
2007年 | 787篇 |
2006年 | 716篇 |
2005年 | 661篇 |
2004年 | 593篇 |
2003年 | 575篇 |
2002年 | 561篇 |
2001年 | 687篇 |
2000年 | 439篇 |
1999年 | 322篇 |
1998年 | 190篇 |
1997年 | 222篇 |
1996年 | 214篇 |
1995年 | 241篇 |
1994年 | 232篇 |
1993年 | 177篇 |
1992年 | 201篇 |
1991年 | 202篇 |
1990年 | 195篇 |
1989年 | 167篇 |
1988年 | 175篇 |
1987年 | 112篇 |
1986年 | 145篇 |
1985年 | 149篇 |
1984年 | 138篇 |
1983年 | 142篇 |
1982年 | 141篇 |
1981年 | 151篇 |
1980年 | 105篇 |
1979年 | 117篇 |
1978年 | 114篇 |
1976年 | 97篇 |
1974年 | 107篇 |
1972年 | 91篇 |
1967年 | 100篇 |
1964年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
65.
66.
67.
68.
H. Kühne 《Die Naturwissenschaften》1957,44(15):431-431
69.
Skelly JM Fredericksen TS Savage JE Snyder KR 《Environmental pollution (Barking, Essex : 1987)》1996,94(2):235-240
Ambient concentrations of ozone (O(3)) and carbon dioxide (CO(2)) were measured at locations from the forest floor to the top of the canopy in a deciduous forest at the Moshannon State Forest in northcentral Pennsylvania. O(3) concentrations were measured from May-September for three years (1993-1995) while CO(2) concentrations were measured only during July and August of 1994. O(3) concentrations increased steadily during the day at all locations, peaking during the middle to late afternoon hours. O(3) concentrations then steadily declined to their lowest point, just before dawn. Vertical O(3) concentration gradients varied seasonally and among years. However, O(3) concentrations were highest within the forest canopy and lowest at the forest floor, with an average difference of approximately 13%. Differences in O(3) concentrations between the canopy and forest floor were greatest at night. O(3) concentrations were slightly higher at locations within the canopy than above the canopy. CO(2) concentrations were consistenly higher near the forest floor and were higher above the canopy than within the canopy. CO(2) concentrations were higher at night than during the day at all locations, especially near the forest floor. 相似文献
70.
Exposure of the temperate sea anemone Anemonia viridis Forskål to increased seawater temperature (from 16 to 26°C) reduced the lysosomal latency of coelenterate tissues. Lysosomes in the mesenterial filaments of anemones were destabilised by increased temperature, with greater destabilisation in heat-shocked symbiotic anemones than in heat-shocked aposymbiotic anemones in the early stages of the experiment. Lysosomal enzyme activity in zooxanthellae from heat-shocked symbiotic anemones was associated with the algal membranes and the cytoplasm of degenerate algal cells. While the relationship between host coelenterate and symbiotic alga may confer many benefits under normal conditions, comparison of the responses of symbiotic and aposymbiotic anemones to heat shock suggests that there may be disadvantages for symbiotic anemones under stress. 相似文献