全文获取类型
收费全文 | 1311篇 |
免费 | 92篇 |
国内免费 | 483篇 |
专业分类
安全科学 | 122篇 |
废物处理 | 68篇 |
环保管理 | 130篇 |
综合类 | 808篇 |
基础理论 | 219篇 |
污染及防治 | 335篇 |
评价与监测 | 73篇 |
社会与环境 | 75篇 |
灾害及防治 | 56篇 |
出版年
2024年 | 9篇 |
2023年 | 21篇 |
2022年 | 75篇 |
2021年 | 70篇 |
2020年 | 69篇 |
2019年 | 51篇 |
2018年 | 63篇 |
2017年 | 62篇 |
2016年 | 87篇 |
2015年 | 82篇 |
2014年 | 117篇 |
2013年 | 130篇 |
2012年 | 120篇 |
2011年 | 123篇 |
2010年 | 111篇 |
2009年 | 91篇 |
2008年 | 85篇 |
2007年 | 90篇 |
2006年 | 73篇 |
2005年 | 49篇 |
2004年 | 37篇 |
2003年 | 40篇 |
2002年 | 36篇 |
2001年 | 39篇 |
2000年 | 21篇 |
1999年 | 29篇 |
1998年 | 16篇 |
1997年 | 21篇 |
1996年 | 13篇 |
1995年 | 12篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 15篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 1篇 |
排序方式: 共有1886条查询结果,搜索用时 140 毫秒
501.
Organochlorine pesticides in the dust fall around Lake Chaohu, the fifth largest lake in China 总被引:2,自引:0,他引:2
Hui-Ling Ouyang Qing-Mei Wang Wei He Ning Qin Xiang-Zhen Kong Wen-Xiu Liu Qi-Shuang He Yu-Jiao Jiang Chen Yang Bin Yang Fu-Liu Xu 《Environmental monitoring and assessment》2014,186(1):383-393
The residual levels of organochlorine pesticides (OCPs) in the dust fall around Lake Chaohu were measured using gas chromatography mass spectrometry from April 2010 to March 2011. The fluxes, components, temporal–spatial variations, and sources of OCPs were also analyzed. Twenty-one types of OCPs were detected in the dust fall samples around Lake Chaohu, with a total concentration of 51.54?±?36.31 ng/g and a total flux of 10.01?±?13.69 ng/(m2 day). Aldrin (35.3 %), endosulfan (39.1 %), dichlorodiphenyltrichloroethanes (DDTs) (49.8 %), and isodrin (37.1 %) were the major OCPs in the spring, summer, autumn, and winter, respectively. Both the residual level and the flux were higher in the spring than in other seasons and higher at the outer lake sampling sites than inner lake sampling site. The potential source of the hexachlorcyclohexanes in the dust fall may be recent lindane usage. The DDTs mainly came from historical dicofol usage, and a significant input of DDT was found during April and June. The presence of endosulfan may be due to the present use of technical endosulfan. The aldrin in the dust might be due to its occasional usage, and isodrin may be a result of long-distance transport from other countries. 相似文献
502.
Quantitative tolerance values for common stream benthic macroinvertebrates in the Yangtze River Delta,Eastern China 总被引:5,自引:0,他引:5
Chun-Yan Qin Jin Zhou Yong Cao Yong Zhang Robert M. Hughes Bei-Xin Wang 《Environmental monitoring and assessment》2014,186(9):5883-5895
Aquatic organisms’ tolerance to water pollution is widely used to monitor and assess freshwater ecosystem health. Tolerance values (TVs) estimated based on statistical analyses of species-environment relationships are more objective than those assigned by expert opinion. Region-specific TVs are the basis for developing accurate bioassessment metrics particularly in developing countries, where both aquatic biota and their responses to human disturbances have been poorly documented. We used principal component analysis to derive a synthetic gradient for four stressor variables (total nitrogen, total phosphorus, dissolved oxygen, and % silt) based on 286 sampling sites in the Taihu Lake and Qiantang River basins (Yangtze River Delta), China. We used the scores of taxa on the first principal component (PC1), which explained 49.8 % of the variance, to estimate the tolerance values (TVr) of 163 macroinvertebrates taxa that were collected from at least 20 sites, 81 of which were not included in the Hilsenhoff TV lists (TVh) of 1987. All estimates were scaled into the range of 1–10 as in TVh. Of all the taxa with different TVs, 46.3 % of TVr were lower and 52.4 % were higher than TVh. TVr were significantly (p?<?0.01, Fig. 2), but weakly (r 2?=?0.34), correlated with TVh. Seven biotic metrics based on TVr were more strongly correlated with the main stressors and were more effective at discriminating references sites from impacted sites than those based on TVh. Our results highlight the importance of developing region-specific TVs for macroinvertebrate-based bioassessment and to facilitate assessment of streams in China, particularly in the Yangtze River Delta. 相似文献
503.
Shuling Song Xiaodong Ma Ling Tong Qin Tian Yi Huang Shaoquan Yin Hongbin Sun 《Environmental monitoring and assessment》2013,185(9):7225-7229
Forty-eight human breast milk samples were collected from mothers in Beijing. The hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) (including α-HCH, β-HCH, γ-HCH, δ-HCH, p,p′-DDE, p,p′-DDD, o,p′-DDT, and p,p′-DDT) contents of the samples were determined by gas chromatography/electron capture detection and gas chromatography/mass spectrometry. α-HCH, β-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, and p,p′-DDT were detected at rates of 20, 100, 10, 100, 10, and 22 %, respectively. The average residue levels in the samples were 174.6 ng/g fat for β-HCH, 333.8 ng/g fat for p,p′-DDE, 6.57 ng/g fat for α-HCH, 7.67 ng/g fat for γ-HCH, 4.18 ng/g fat for p,p′-DDD, and 11.4 ng/g fat for p,p′-DDT. The results showed that the infants’ daily intake levels of HCH and DDT were 0.95 and 1.76 μg/kg body weight/day, respectively. Our result suggested that the total residue level of these organochlorine pesticides in breast milk from Beijing decreased and was lower than that from other coastal and heavy industrial cities in China. On the other hand, the levels of HCH and DDT were higher than those from some developed countries, but lower than those from other developing countries such as India. 相似文献
504.
505.
506.
507.
对2017年除夕至初一期间(1月27—28日),湖南省14个市州的78个城市环境空气自动监测站点数据进行了分析。结果表明,烟花爆竹的集中燃放会在短时间内造成严重的大气污染,其中,对PM10和PM2.5影响最为显著,其次是SO2,NO2和O3受影响程度相对最小。集中燃放烟花对PM10和PM2.5的小时值增长倍数贡献明显。对全省14个城市PM10和PM2.5的小时值最大贡献量分别为195~652和116~680 μg/m3;最大增高倍数分别为1.8~10.5倍和2.2~15.8倍。其中对郴州市的影响程度最高。城市集中燃放烟花爆竹期间,ρ(PM2.5)/ρ(PM10)明显上升,初一01:00最大值为0.69。气象条件也是影响春节期间空气质量的重要因素,风速小、逆温强、湿度大和无降水等不利气象条件使污染物浓度不断累积,形成持续性污染过程。 相似文献
508.
集约化养猪废水SBR中17β-雌二醇高效降解菌的分离鉴定及其降解特性 总被引:2,自引:0,他引:2
从集约化养猪废水生物处理SBR的活性污泥中分离到3株高效降解17β-雌二醇(E2)的菌株,分别命名为ha、chs和hc。研究表明,这3株菌以E2为惟一碳源,在4 d内对初始浓度为1 mg/L E2的降解率为70%~95%。25℃条件下菌ha、chs和hc的一级反应动力学常数分别为0.0086、0.072和0.013。在温度为37℃时,3株菌的降解效率最高,在高浓度的氨氮和碱性pH的条件下,这3株菌均存在降解作用。其中,pH 9.05时,一级动力学常数菌ha降至0.0066,菌chs升至0.076,菌hc降至0.012。同时,在添加C源后,对降解有促进作用,并且C/N比在15∶1时降解效果较好。3株菌的一级反应动力学常数分别升到0.027、0.73和0.021。经16S rRNA基因序列分析鉴定为枯草芽孢肝菌(Bacillus subtilis)。 相似文献
509.
多元微电解技术对高浓度化学清洗废水预处理的影响 总被引:1,自引:1,他引:0
以高浓度化学清洗废水为研究对象,分别考察了常规混凝沉淀、多元微电解2种工艺对有机物污染物的去除效率和改善废水可生化性的效果。结果表明:多元微电解工艺的最佳pH 3.0,填充比1∶3,微电解1 h,气水比1∶1的条件下,其对COD平均去除率可达到60%,而直接混凝沉淀仅为10.5%,多元微电解工艺能使BOD5/COD值由原来的0.12升高到0.32,提高了废水的可生化性,减轻了后续生化处理负荷,是对高浓度化学清洗废水的有效预方法。 相似文献
510.
Qin Hua 《中国人口.资源与环境(英文版)》2012,10(3):9-17
Abstract: Migration process has become increasingly important in recent research on population and the environment. A majority of the existing migration and environment literature has focused on the en... 相似文献