全文获取类型
收费全文 | 1901篇 |
免费 | 266篇 |
国内免费 | 1326篇 |
专业分类
安全科学 | 188篇 |
废物处理 | 61篇 |
环保管理 | 92篇 |
综合类 | 1737篇 |
基础理论 | 1017篇 |
污染及防治 | 266篇 |
评价与监测 | 121篇 |
社会与环境 | 5篇 |
灾害及防治 | 6篇 |
出版年
2024年 | 33篇 |
2023年 | 105篇 |
2022年 | 114篇 |
2021年 | 164篇 |
2020年 | 101篇 |
2019年 | 128篇 |
2018年 | 108篇 |
2017年 | 134篇 |
2016年 | 128篇 |
2015年 | 134篇 |
2014年 | 205篇 |
2013年 | 158篇 |
2012年 | 159篇 |
2011年 | 149篇 |
2010年 | 153篇 |
2009年 | 150篇 |
2008年 | 128篇 |
2007年 | 150篇 |
2006年 | 133篇 |
2005年 | 107篇 |
2004年 | 86篇 |
2003年 | 89篇 |
2002年 | 75篇 |
2001年 | 72篇 |
2000年 | 50篇 |
1999年 | 56篇 |
1998年 | 66篇 |
1997年 | 67篇 |
1996年 | 53篇 |
1995年 | 77篇 |
1994年 | 53篇 |
1993年 | 38篇 |
1992年 | 18篇 |
1991年 | 22篇 |
1990年 | 14篇 |
1989年 | 12篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有3493条查询结果,搜索用时 343 毫秒
331.
改性粉煤灰在处理锑矿选矿废水中的应用 总被引:9,自引:1,他引:8
针对锑矿选矿废水中锑和丁基黄原酸钠严重超标的问题,用酸改性粉煤灰对其进行吸附处理.试验结果表明,当改性粉煤灰处理选矿废水的最佳质量体积比(g.mL-1)为1:100,pH值为3,静置时间为4h时,可以将选矿废水中的锑浓度从28.611mg.L-1降到0.05mg.L-1以下,去除率达99.8%以上;废水中的丁基黄原酸钠浓度可从0.373mg.L-1降到0.02mg.L-1以下,去除率达95.0%以上.处理废水后的改性粉煤灰用硫酸-硝酸浸提,浸出液中重金属离子浓度均低于国家浸出毒性标准,表明改性粉煤灰是一种很好的锑矿选矿废水处理剂. 相似文献
332.
氯酚类化合物对青鱼和细鳞斜颌鯝幼鱼的毒性 总被引:10,自引:1,他引:9
以我国特有青鱼和细鳞斜颌鯝为受试物种,利用其生命早期阶段的急性毒性LC50值和28d慢性生长抑制试验所获得的最大可接受浓度(MATC)评价了3种氯酚类化合物的毒性效应.实验结果显示,2,4-二氯酚(2,4-DCP),2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)对青鱼和细鳞斜颌鯝的的96hLC50值分别为4.01(3.61~4.68)、1.22(1.12~1.31)、0.10(0.08~0.11)mg·mL-1和2.48(1.94~2.89)、1.10(0.38~1.36)、0.09(0.08~0.10)mg·mL-1,且3种氯酚类化合物对青鱼的毒性和细鳞斜颌鲴的毒性存在良好的线性相关性.根据化学物质对鱼类毒性分级标准,PCP对青鱼和细鳞斜颌鲴均为剧毒,2,4-DCP和2,4,6-TCP对青鱼和细鳞斜颌鲴均为高毒.青鱼对2,4-DCP,2,4,6-TCP和PCP的MATC分别为0.05mg·mL-1、0.10mg·mL-1和0.015mg·mL-1,对应的急慢性毒性比(ACR)分别为80.2、12.2和6.67;细鳞斜颌鲴对2,4-DCP、2,4,6-TCP和PCP的MATC分别为0.30mg·mL-1、0.15mg·mL-1和0.01mg·mL-1,对应ACR分别为8.27、7.33和9.00. 相似文献
333.
334.
Accumulation of copper (Cu) and cadmium (Cd) in six rice cultivars (94D-22, 94D-54, 94D-64, Gui630, YY-1 and KY1360) was evaluated through exposure to heavy metal contamination (100 mg/kg Cu, 1.0 mg/kg Cd, and 100 mg/kg Cu + 1.0 mg/kg Cd) in a greenhouse. The dry weight of shoot and root, concentrations of Cu and Cd in plant tissues and the Cu, Cd, P, Fe concentrations in the root surface iron plaques were analyzed eight weeks later after treatment. The results indicated that the plant biomass was mainly determined by rice genotypes, not Cu and Cd content in soil. Separated treatment with Cu/Cd increased each metal level in shoot, root and iron plaques. Soil Cu enhanced Cd accumulation in tissues. In contrast, Cu concentrations in shoot and root was unaffected by soil Cd. Compared to single metal contamination, combined treatment increased Cd content by 110.6%, 77.0% and 45.2% in shoot, and by 112.7%, 51.2% and 18.4% in root for Gui630, YY-1 and KY1360, respectively. The content level of Cu or Cd in root surface iron plaques was not affected by their soil content. Cu promoted Fe accumulation in iron plaques, while Cd has no effect on P and Fe accumulation in it. The translocation of Cu and Cd from iron plaques to root and shoot was also discussed. These results might be beneficial in selecting cultivars with low heavy metal accumulation and designing strategies for soil bioremediation. 相似文献
335.
Acute toxicity of excess Cu on the photosynthetic performance of Chlorella pyrenoidosa was examined by using chlorophyll a fluorescence transients and JIP-test after exposure to elevated Cu concentrations for a short time period. High Cu concentration resulted in a significant suppression in photosynthesis and respiration. The absorption flux (ABS/RC) per PSII reaction center increased with increasing Cu concentration, but the electron transport flux (ET0/RC) decreased. Excess Cu had an insignificant effect on the trapping flux (TR0/RC). The decline in the efficiency, with which a trapped exciton can move an electron into the electron transport chain further than QA−(Ψ0), the maximal quantum yield of primary photochemistry (?P0), and the quantum yield of electron transport (?E0) were also observed. The amount of active PSII reaction centers per excited cross section (RC/CS) was also in consistency with the change of photosynthesis when cells were exposed to excess Cu concentration. JIP-test parameters had a good linear relationship with photosynthetic O2 evolution. These results suggested that the decrease of photosynthesis in exposure to excess Cu may be a result of the inactivation of PSII reaction centers and the inhibition of electron transport in the acceptor side. 相似文献
336.
文章主要研究模拟高放废液加入沸石预处理经碱矿渣水泥固化后Cs+的浸出性能。实验结果表明,处理含Cs+高放废液固化体中加入沸石,能使Cs+浸出率降低";两步法"掺入沸石固化体抗Cs+浸出性能更有所提高;pH值升高Cs+的吸附比增大。 相似文献
337.
338.
339.
340.
Using the nematode Caenorhabditis elegans as a model animal for assessing the
toxicity induced by microcystin-LR 总被引:1,自引:0,他引:1
Among more than 75 variants of microcystin(MC),microcystin-LR(MC-LR) is one of the most common toxins.In this study,the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied.C.elegans was treated with MC-LR at different concentrations ranging from 0.1 to 80 μg/L.The results showed that MC-LR could reduce lifespan,delay development,lengthen generation time,decrease brood size,suppress locomotion behavior,and decreases hsp-16-2-gfp expression.The endpoints of generation time,brood... 相似文献