全文获取类型
收费全文 | 864篇 |
免费 | 230篇 |
国内免费 | 215篇 |
专业分类
安全科学 | 48篇 |
废物处理 | 7篇 |
环保管理 | 47篇 |
综合类 | 393篇 |
基础理论 | 665篇 |
污染及防治 | 71篇 |
评价与监测 | 40篇 |
社会与环境 | 23篇 |
灾害及防治 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 44篇 |
2022年 | 42篇 |
2021年 | 51篇 |
2020年 | 49篇 |
2019年 | 39篇 |
2018年 | 92篇 |
2017年 | 60篇 |
2016年 | 54篇 |
2015年 | 76篇 |
2014年 | 63篇 |
2013年 | 109篇 |
2012年 | 68篇 |
2011年 | 82篇 |
2010年 | 68篇 |
2009年 | 52篇 |
2008年 | 53篇 |
2007年 | 41篇 |
2006年 | 45篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 24篇 |
2002年 | 20篇 |
2001年 | 13篇 |
2000年 | 13篇 |
1999年 | 19篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有1309条查询结果,搜索用时 250 毫秒
511.
Rising temperatures, a widespread consequence of climate change, have been implicated in enigmatic amphibian declines from habitats with little apparent human impact. The pathogenic fungus Batrachochytrium dendrobatidis (Bd), now widespread in Neotropical mountains, may act in synergy with climate change causing collapse in thermally stressed hosts. We measured the thermal tolerance of frogs along a wide elevational gradient in the Tropical Andes, where frog populations have collapsed. We used the difference between critical thermal maximum and the temperature a frog experiences in nature as a measure of tolerance to high temperatures. Temperature tolerance increased as elevation increased, suggesting that frogs at higher elevations may be less sensitive to rising temperatures. We tested the alternative pathogen optimal growth hypothesis that prevalence of the pathogen should decrease as temperatures fall outside the optimal range of pathogen growth. Our infection‐prevalence data supported the pathogen optimal growth hypothesis because we found that prevalence of Bd increased when host temperatures matched its optimal growth range. These findings suggest that rising temperatures may not be the driver of amphibian declines in the eastern slopes of the Andes. Zoonotic outbreaks of Bd are the most parsimonious hypothesis to explain the collapse of montane amphibian faunas; but our results also reveal that lowland tropical amphibians, despite being shielded from Bd by higher temperatures, are vulnerable to climate‐warming stress. Fisiología Termal, Enfermedades y Disminuciones de Anfibios en las Laderas Orientales de los Andes 相似文献
512.
513.
With high performance liquid chromatograph and fluorospectrometry, 1-hydroxypyrene is identified as a metabolite of pyrene in the urine of dogs after intramuscular injection of pyrene. When three successive doses of 1,2 and 5 μmol/kg wt. pyrene administered, urinary excretion of 1-hydroxypyrene reaches the peak level between 24th and 48th hours. Excreted 1-hydroxypyrene consists of only about 0.05% of injected pyrene. 相似文献
514.
515.
丁孝泉 《安全.健康和环境》2003,3(7):14-14,19
叙述了油田井下作业TK—5型全自动液气控制天车安全装置的工作原理,分析了该装置的安全可靠性。 相似文献
516.
517.
赵洪发 《防灾科技学院学报》2007,9(1):21-24
本文通过历史的回顾,总结了学院"创造良好氛围,启发进步意识,加强入党培训,把握环节教育,提供实践途径,注意善后工作"的学生组织发展工作的一条路子.在党建和思想政治工作方面,对于了解过去和指导当前的工作,都具有一定的参考意义. 相似文献
518.
本文在评价用传统方法即赤平极射投影和实体比例投影方法分析节理边坡稳定性的基础上,结合具体工程实例引进了优势结构面的确定、岩体破坏模式的运动学判释、可移动块体的几何判定和关键块体的确定等方法, 使传统方法得到拓宽和完善,从而具有更好的适用性和可操作性。 相似文献
519.
Xia Xinghui Meng Lihong Hu Lijuan 《Frontiers of Environmental Science & Engineering in China》2007,1(2):172-178
Experiments have been carried out to study the sorption of Benzo(a)pyrene(Bap) on sediment particles from the Yellow River
using a batch equilibration technique. Effects of particle size on the adsorption and partition of Bap were investigated with
the particle content of 3 g/L. Several significant results were obtained from the study. (1) Isotherms of Bap could be fitted
with the dual adsorption-partition model under different particle sizes, and the measured value of the adsorption and partition
was in agreement with the theoretical value of the dual adsorption-partition model. (2) When the particle diameter was d ⩾ 0.025 mm, the adsorption was predominant in the sorption of Bap, which accounted for 68.7%–82.4% of the sorption. For the
particles with the size of 0.007 mm⩽d<0.025 mm, the adsorption was predominant when the equilibrium concentration of Bap was 0–8.87 μg/L in the water phase; and
the partition was predominant when the equilibrium concentration of Bap was higher than 8.87 μg/L in the water phase. When
the particle diameter was d<0.007 mm, the partition was predominant. (3) On the point of particle size, the contribution of adsorption to sorption followed
the order: “d⩾0.025 mm”>“0.007 mm ⩽d<0.025 mm” >“d<0.007 mm”. (4) The partition coefficients of Bap in solids with different particle sizes were linearly correlated with the
organic content, and the K
oc of Bap was about 1.26 × 105 (L/kg).
Translated from Acta Scientiae Circumstantiae, 2006, 26(2): 269–274 [译自: 环境科学学报] 相似文献
520.
以射阳县环境监测站通过合并评审为例,分析了合并评审的社会环境、政策环境,阐述了合并评审应注意的4个环节,对基层环境监测、计量认证和实验室认可的合并评审工作,具有一定的借鉴价值. 相似文献