全文获取类型
收费全文 | 736篇 |
免费 | 16篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 125篇 |
废物处理 | 7篇 |
环保管理 | 47篇 |
综合类 | 329篇 |
基础理论 | 68篇 |
环境理论 | 1篇 |
污染及防治 | 60篇 |
评价与监测 | 62篇 |
社会与环境 | 32篇 |
灾害及防治 | 33篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 18篇 |
2020年 | 17篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 15篇 |
2014年 | 34篇 |
2013年 | 57篇 |
2012年 | 42篇 |
2011年 | 49篇 |
2010年 | 29篇 |
2009年 | 44篇 |
2008年 | 29篇 |
2007年 | 46篇 |
2006年 | 42篇 |
2005年 | 26篇 |
2004年 | 32篇 |
2003年 | 21篇 |
2002年 | 25篇 |
2001年 | 23篇 |
2000年 | 13篇 |
1999年 | 19篇 |
1998年 | 30篇 |
1997年 | 21篇 |
1996年 | 16篇 |
1995年 | 13篇 |
1994年 | 14篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有764条查询结果,搜索用时 0 毫秒
691.
692.
Noriyuki Momoshima Fumio Inoue Jun Shimada 《Journal of environmental radioactivity》2010,101(8):615-621
Atmospheric 85Kr concentration at Fukuoka, Japan was determined by an improved 85Kr analytical method using liquid scintillation counting (LSC). An average value of 1.54 ± 0.05 Bq m−3 was observed in 2008, which is about two times that measured in 1981 at Fukuoka, indicating a 29 mBq y−1 rate of increase as an average for these 27 years. The analytical method developed involves collecting Kr from air using activated charcoal at liquid N2 temperature and purifying it using He at dry ice temperature, followed by Kr separation by gas chromatography. An overall Kr recovery of 76.4 ± 8.1% was achieved when Kr was analyzed in 500-1000 l of air. The Kr isolated by gas chromatography was collected on silica gel in a quartz glass vial cooled to liquid N2 temperature and the activity of 85Kr was measured with a low-background LS counter. The detection limit of 85Kr activity by the present analytical method is 0.0015 Bq at a 95% confidence level, including all propagation errors, which is equivalent with 85Kr in 1.3 l of the present air under the analytical conditions of 72.1% counting efficiency, 0.1597 cps background count rate, and 76.4% Kr recovery. 相似文献
693.
Hussain T Gondal MA Yamani ZH Baig MA 《Environmental monitoring and assessment》2007,124(1-3):131-139
Laser-induced breakdown spectroscopy (LIBS) has been applied for the determination of nutrients in the green house soil samples.
We determined appropriate spectral signatures of vital nutrients and calibrated the method to measure the nutrients in a naturally
fertilized plot, cultivated with tomato and cucumber plants. From the calibration curves we predicted the concentrations of
important nutrients such as Ca, K, P, Mg, Fe, S, Ni and Ba in the soil. Our measurements proved that the LIBS method rapidly
and efficiently measures soil nutrients with excellent detection limits of 12, 9, 7, 9, 7, 10, 8 and 12~mg/kg for Ca, K, P,
Mg, Fe, S, Ni and Ba respectively with a precision of 2%, The unique features of LIBS for rapid sample analysis demonstrated
by this study suggests that this method offers promise for precision measurements of soil nutrients as compared to conventional
methods in short span of time. 相似文献
694.
Ikem A Campbell M Nyirakabibi I Garth J 《Environmental monitoring and assessment》2008,140(1-3):69-81
Anthropogenic sources of pollution can significantly contribute to elevated concentrations of toxic elements in soils. A preliminary
survey of trace elements content and their availability in residential soils from New Madrid County, Missouri was undertaken.
Mean elemental concentrations (mg kg−1, dry wt) of sixty two soil samples were: As 6.6, Be 0.8, Cd 1.6, Co 9.7, Cr 24.5, Cu 18.1, Fe 9951, Mn 298, Ni 15.6, Pb 48.8,
V 42.1, Zn 95.5 and Hg 0.05. The US EPA preliminary remediation goals (PRGs) was only exceeded by As (7 % of samples) and
V (8% of samples). The Missouri average background values were exceeded by Pb (69%), Zn (31%), Cu (27%), As (23%), Be (19%),
Co (18%), Ni (16%), V (8%) and Mn (2%). Crustal enrichments (EFc) for As (97), Cr (6), Cu (10), Pb (121), V (7), and Hg (17) were highest for North Lilbourn soils. Fractionation experiment
revealed that Fe (54–79%) was in the residual phase while Zn (70–90%), Mn (88–92%), As (59–81%) and Pb (63–79%) were potentially
available in soils. Factor loadings of the element concentrations on principal components 1, 2 and 3 accounted for over 81%
variance of the data set. The factor loadings suggested that apart from natural contributions of trace elements to the soils,
human activities possibly accounted for other inputs in soils. 相似文献
695.
696.
地表水悬浮物分析中的几个问题 总被引:2,自引:0,他引:2
张向东 《环境监测管理与技术》2000,12(1):40-41
对地表水悬浮物分析中的样品烘干时间、次数和取样问题进行了实验,提出了减少悬的体操的烘干恒重次数、缩短分析过程呼时间的意见。同时提出悬浮物应单独采集样品,以提高悬浮物的分析质量。 相似文献
697.
煤气化过程中气态污染物采样分析的研究进展 总被引:1,自引:0,他引:1
通过考察气态污染物采样方法的基本原理,对比分析国内外常压采样系统和加压采样系统的设计特征,选择煤气化过程中5种常见气态污染物为分析对象,列举常用的化学分析法和仪器分析法,为加压气化装置采样系统的设计提供参考材料和建议,归纳了一些有助于提高气态污染物检测数据可靠性的措施,希望能为煤气化过程中(特别是加压煤气化过程中)气态污染物采样系统的设计提供思路和借鉴。 相似文献
698.
Totally 117 cloud/fog water samples were collected at the summit of Mt. Tai (1534 m a.s.l.)—the highest mountain in the Northern China Plain. The results were investigated by a combination of techniques including back trajectory model, regional air quality and dust storm models, satellite observations and Principal Component Analysis. Elemental concentrations were determined by Inductively Coupled Plasma Mass Spectrometry, with stringent quality control measures. Higher elemental concentrations were found at Mt. Tai compared with those reported by other overseas studies. The larger proportions and higher concentrations of toxic elements such as Pb and As in cloud/fog water compared with those in rainwater at Mt. Tai suggests higher potential hazards of cloud/fog water as a source of contamination in polluted areas to the ecosystem. Peak concentrations of trace elements were frequently observed during the onset of cloud/fog events when liquid water contents of cloud/fog water were usually low and large amount of pollutants were accumulated in the ambient air. Inverse relationship between elemental concentrations and liquid water contents were only found in the samples with high electrical conductivities and liquid water contents lower than 0.3 g m−3. Affected mainly by the emissions of steel industries and mining activities, air masses transported from south/southwest of Mt. Tai were frequently associated with higher elemental concentrations. The element Mn is attributed to play an important role in the acidity of cloud/fog water. The composition of cloud/fog water influenced by an Asian dust storm event was reported, which was seldom found in the literature. 相似文献
699.
《Journal of environmental science and health. Part. B》2013,48(5-6):737-746
Abstract A high-performance liquid chromatography method with diode-array detection (HPLC-DAD) is described for the determination of three neonicotinoid insecticides imidacloprid, thiacloprid, and thiamethoxam in soil and water. The soil samples were extracted with acetonitrile, while the water samples were extracted using C18 cartridges. The mean recoveries plus standard deviations for spiked soil samples were 82 ± 4.2% for thiamethoxam, 99 ± 4.2% for imidacloprid and 94 ± 1.4% for thiacloprid. The recoveries for water samples ranged from 87 ± 3.4% for thiamethoxam to 97 ± 3.9% for imidacloprid and 97 ± 2.6% for thiacloprid. The limits of quantitation (LOQ) were 0.1, 0.1, 0.01 mg/kg in soil (5 g), and 2, 2, 0.5 µg/L in water (50 mL) for thiamethoxam, imidacloprid, and thiacloprid, respectively. 相似文献
700.
《Environmental Forensics》2013,14(1):59-79
Environmental forensic analysis has evolved significantly from the early days of qualitative chemical fingerprint evaluations. The need for quantitative rigor has made the use of numerical methods critical in identifying and mapping contaminant sources in complex environmental systems. Given multiple contaminant sources, the environmental scientist is faced with the challenge of unraveling the contributions of multiple plumes with overlapping spatial and temporal distributions. The problem may be addressed through a multivariate statistical approach, but there is a mind-boggling array of the available "chemometric" methods. This paper provides an overview of these methods, along with a review of their advantages, disadvantages, and pitfalls. Methods discussed include principal component analysis and several receptor-modeling techniques. 相似文献