全文获取类型
收费全文 | 2524篇 |
免费 | 173篇 |
国内免费 | 830篇 |
专业分类
安全科学 | 240篇 |
废物处理 | 108篇 |
环保管理 | 201篇 |
综合类 | 1521篇 |
基础理论 | 407篇 |
污染及防治 | 626篇 |
评价与监测 | 145篇 |
社会与环境 | 151篇 |
灾害及防治 | 128篇 |
出版年
2024年 | 6篇 |
2023年 | 40篇 |
2022年 | 109篇 |
2021年 | 128篇 |
2020年 | 118篇 |
2019年 | 91篇 |
2018年 | 93篇 |
2017年 | 143篇 |
2016年 | 95篇 |
2015年 | 130篇 |
2014年 | 148篇 |
2013年 | 197篇 |
2012年 | 196篇 |
2011年 | 190篇 |
2010年 | 171篇 |
2009年 | 167篇 |
2008年 | 158篇 |
2007年 | 194篇 |
2006年 | 144篇 |
2005年 | 95篇 |
2004年 | 107篇 |
2003年 | 93篇 |
2002年 | 96篇 |
2001年 | 97篇 |
2000年 | 96篇 |
1999年 | 78篇 |
1998年 | 67篇 |
1997年 | 65篇 |
1996年 | 44篇 |
1995年 | 38篇 |
1994年 | 24篇 |
1993年 | 25篇 |
1992年 | 29篇 |
1991年 | 8篇 |
1990年 | 12篇 |
1989年 | 16篇 |
1988年 | 10篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有3527条查询结果,搜索用时 62 毫秒
211.
Occurrence of organotins in the Yangtze River and the Jialing River in the urban section of Chongqing, China 总被引:2,自引:0,他引:2
Jun-Min Gao Ying Zhang Jin-Song Guo Fen Jin Ke Zhang 《Environmental monitoring and assessment》2013,185(5):3831-3837
The occurrence of organotins in the Yangtze River and the Jialing River in the urban section of Chongqing, China and their impact on drinking water waterworks are reported in this study. Water samples were extracted by solid-phase microextraction and measured using a gas chromatograph with mass spectrometer. The results showed that the rivers studied were polluted by both butyltins and phenyltins and that the butyltin species was the dominant pollutant. Butyltins, especially monobutyltin, were detected in all 18 sampling stations, and phenyltins were detected only in 11 sampling stations. Majority of the organotins were MBTs with concentrations varying from 27.3 to 1,145.8 ng Sn L?1. Diphenyltin and dibutyltin were the second most common with the highest levels of 113.7 and 202.5 ng Sn L?1, respectively. Monophenyltin, tributyltin, and triphenyltin had the lowest detection rates with concentration levels of 9.7, 161.8, and 37.2 ng Sn L?1, respectively. Some of the organotins were also detected in drinking water waterworks, which posed a threat to the water quality of Chongqing. 相似文献
212.
通过对我国辐射环境监测相关法规的调研,在深入分析当前辐射环境监测法规框架结构和突出问题的基础上,构建我国辐射环境监测法规体系,重点关注辐射环境质量监测、核与辐射监督性监测及应急监测等方面的工作需求,提出完善部门规章、健全核安全导则及规范性文件的建议。 相似文献
213.
Zhang Q Wang C Zhang X Jin D Huang C Zhao M 《Journal of environmental monitoring : JEM》2012,14(2):465-472
Chiral pesticides are ubiquitous in the aquatic environment, and their enantioselectivities in aquatic toxicity are known to be complicated. The difference in enantioselective effects between enantiomers may sometimes differ by approximately 100-fold or more, which makes it important to incorporate enantioselective effects into the risk assessment of chiral pesticides. In this paper, we reviewed relevant work on the aquatic toxicity of chiral pesticides with an emphasis on the enantioselective aquatic toxicity under both chronic and acute exposure conditions. We provided a personal account of the importance of studies on molecular mechanisms of developmental toxicity and specific endpoints such as vitellogenin, yolk sac edema and pericardial edema in future research. Given the widespread use of chiral pesticides, we suggest that a more comprehensive understanding of the significance of enantioselective aquatic toxicity will be very helpful in improving risk assessment and regulation of chiral pesticides. 相似文献
214.
Na Wang You-Gan Wang Shuwen Hu Zhi-Hua Hu Jing Xu Hongwu Tang Guangqiu Jin 《Environmental Modeling and Assessment》2018,23(6):779-786
We introduce robust procedures for analyzing water quality data collected over time. One challenging task in analyzing such data is how to achieve robustness in presence of outliers while maintaining high estimation efficiency so that we can draw valid conclusions and provide useful advices in water management. The robust approach requires specification of a loss function such as the Huber, Tukey’s bisquare and the exponential loss function, and an associated tuning parameter determining the extent of robustness needed. High robustness is at the cost of efficiency loss in parameter loss. To this end, we propose a data-driven method which leads to more efficient parameter estimation. This data-dependent approach allows us to choose a regularization (tuning) parameter that depends on the proportion of “outliers” in the data so that estimation efficiency is maximized. We illustrate the proposed methods using a study on ammonium nitrogen concentrations from two sites in the Huaihe River in China, where the interest is in quantifying the trend in the most recent years while accounting for possible temporal correlations and “irregular” observations in earlier years. 相似文献
215.
城镇化过程中的流域面源污染时空变化 总被引:1,自引:0,他引:1
以斧头湖流域为研究对象,在野外调查的基础上,借助遥感和GIS技术,对2008年、2015年斧头湖流域土地利用格局、人畜排放进行分析,利用输出系数模型解析斧头湖的面源污染负荷时空分布及主要来源。结果表明:斧头湖流域2008~2015年面源总氮(TN)和总磷(TP)负荷输出分别从由原来的 2 915 和 178 t 增长至 3 252 和 202 t。城镇化发展使得农村耕地面积减少,耕地对TN的输出贡献比例降低,但是耕地化肥使用依然是TN最主要来源。城镇化使得居民区对面源贡献增大,特别是TP的贡献显著增加。随着人们生活水平的提高,畜禽养殖对面源污染的贡献也显著增加,应予以足够重视 相似文献
216.
吹扫捕集-气相色谱法测定汽油类有机物 总被引:1,自引:0,他引:1
采用吹扫-捕集富集、DB624毛细管柱分离,气相色谱FID检测汽油类化合物,使用4-溴氟苯代用品标准作为质量控制物质,保证了测定全过程处于受控之中。该法具有较高的灵敏度和良好的线性关系,应用于实际样品的分析,水样中汽油检测限0.04mg/L,土样的汽油检测限为2.2mg/kg。回收率在92%~105%之间。相对标准差为2.5%,分析结果令人满意。 相似文献
217.
Just before the new round of UN climate change conference in Bonn, a survey report, named as the Climate Change in the Chinese Mind 2017, was released in Beijing. The investigation was conducted in the form of a computer-assisted telephone survey with a sample size of 4,025 samples, covering 332 prefecture-level administrative units and four municipalities in China. Urban-rural proportion and sex proportion were specially taken into account, so as to demonstrate the Chinese public awareness objectively. The investigation measures the public awareness from six aspects, which includes climate change beliefs, impacts, response, policies, actions, and the assessment of the effectiveness of climate communication. This article presents the key findings of the survey and provides further insights behind the data. 相似文献
218.
Liumeng Pan Liping Lu Jingpeng Wang Cunwu Zheng Yujie Fu Siyuan Xiao Yating Jin Shulin Zhuang 《Environmental Chemistry Letters》2017,15(4):673-678
The fungicide difenoconazole has been frequently detected in agricultural products, soils and surface waters, causing increasingly public concern due to toxicological properties. Although systemic triazole fungicides can inhibit the enzymatic activity of many CYP450 isozymes, how difenoconazole affects the human CYP3A4 still remains largely unknown. We thus investigated the effect of difenoconazole on normal mRNA expression and protein expression of human CYP3A4 by real-time quantitative PCR and western blot, respectively. Results show that the exposure to difenoconazole from 0.01 to 0.5 μM for 24 h down-regulates mRNA expression levels of human CYP3A4 in HepG2 cells. We also found that difenoconazole could inhibit the enzymatic activity of human CYP3A4 in a concentration-dependent mode. The IC50 of difenoconazole for inhibition of CYP3A4 activity is 0.41 µM, showing a stronger inhibitor in comparison with ketoconazole. Overall, our findings indicate the potential risk of difenoconazole for the disruption of human CYP3A4. 相似文献
219.
苏丹红是一种人工合成偶氮染料,可引起肝脏及泌尿系统等多个脏器的肿瘤,但苏丹红对生殖系统的毒性研究较少。本研究以昆明小鼠为受试对象,探讨苏丹红I对小鼠卵巢组织Caspase-3和Ki-67表达的影响。将24只昆明小鼠随机分为:对照组、低剂量(60 mg·kg~(-1))、中剂量(120 mg·kg~(-1))、高剂量(240 mg·kg~(-1))4组,6只/组。胃灌4周,4周末处死。HE染色观察各组卵巢组织病理变化,免疫组化法检测卵巢组织Caspase-3和Ki-67表达,Real time PCR检测卵巢组织Caspase-3和Ki-67 m RNA表达,Western blotting检测卵巢组织中Ki-67及Caspase-3蛋白表达。与对照组比较,实验组卵巢中Caspase-3阳性细胞率显著升高(P0.05),而Ki-67阳性细胞率显著降低(P0.05),Real time PCR及Western blotting结果与免疫组化法结果一致。本实验发现苏丹红染毒后颗粒细胞的Caspase-3表达增加,且Caspase-3表达呈剂量依赖性,但Ki-67表达受到抑制。 相似文献
220.