全文获取类型
收费全文 | 684篇 |
免费 | 68篇 |
国内免费 | 421篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 47篇 |
环保管理 | 38篇 |
综合类 | 649篇 |
基础理论 | 180篇 |
污染及防治 | 128篇 |
评价与监测 | 98篇 |
社会与环境 | 17篇 |
灾害及防治 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 34篇 |
2021年 | 22篇 |
2020年 | 16篇 |
2019年 | 40篇 |
2018年 | 39篇 |
2017年 | 48篇 |
2016年 | 64篇 |
2015年 | 67篇 |
2014年 | 82篇 |
2013年 | 105篇 |
2012年 | 67篇 |
2011年 | 49篇 |
2010年 | 65篇 |
2009年 | 42篇 |
2008年 | 42篇 |
2007年 | 56篇 |
2006年 | 46篇 |
2005年 | 49篇 |
2004年 | 45篇 |
2003年 | 25篇 |
2002年 | 17篇 |
2001年 | 35篇 |
2000年 | 30篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 17篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
排序方式: 共有1173条查询结果,搜索用时 15 毫秒
851.
Thomas H. Suchanek Peter J. Richerson John R. Flanders Douglas C. Nelson Lauri H. Mullen Linnie L. Brister Jesse C. Becker 《Environmental monitoring and assessment》2000,64(1):299-310
Mercury (Hg) in the aquatic ecosystem of Clear Lake has been documented since the 1970s when fishes were found to have elevated levels of toxic methyl mercury (meHg). Mining practices at the Sulphur Bank Mercury Mine (active intermittently from 1872–1957) along the shoreline of Clear Lake included the bulldozing of waste rock and overburden ore into the shallow nearshore regions of the lake and the creation of steeply sloped piles of waste rock at the water's edge. This process, plus erosion of the waste rock piles, resulted in the accumulation of an estimated 100 metric tons of Hg in Clear Lake. A monitoring program to assess Hg in Clear Lake was established in 1992, and conducted continuously from 1994. Drought conditions in California had persisted for ca. 6 yrs prior to 1992, when the U.S. Environmental Protection Agency (USEPA) remediated the steeply sloped eroding waste rock piles, which appeared to reduce sediment Hg concentrations significantly. In April 1995, a white flocculent material was observed in Clear Lake adjacent to the mine and has been observed every year since, leading to the discovery of ongoing acid mine drainage (AMD), low pH fluids high in Hg and extremely high in sulfate. AMD is now believed to be the most likely cause of elevated meHg in Clear Lake. The discovery of this source of meHg production in Clear Lake, which will significantly influence remedial options, was only made possible by implementation of a diligent monitoring program. 相似文献
852.
We monitored nest boxes during 1997–1999 at Acadia National Park, Mt. Desert Island, ME and at an old-field site in Orono,
ME to determine mercury (Hg) uptake in tree swallow (Tachycineta bicolor) eggs, tissues, and food boluses. Also, in 1998–1999 we monitored nest boxes at Grove Pond and Plow Shop Pond at a U.S. Environmental
Protection Agency Superfund site in Ayer, MA. We recorded breeding success at all locations. On average among locations, total
mercury (THg) biomagnified 2 to 4-fold from food to eggs and 9 to 18-fold from food to feathers. These are minimum values
because the proportion of transferable methyl mercury (MeHg) of the THg in insects varies (i.e., 35%–95% of THg) in food boluses.
THg was highest in food boluses at Aunt Betty Pond at Acadia, whereas THg in eggs was highest at the Superfund site. A few
eggs from nests at each of these locations exceeded the threshold (i.e., 800–1,000 ng/g, wet wt.) of embryotoxicity established
for Hg. Hatching success was 88.9% to 100% among locations, but five eggs failed to hatch from 4 of the 11 clutches in which
an egg exceeded this threshold. MeHg in feathers was highest in tree swallows at Aunt Betty Pond and the concentration of
THg in bodies was related to the concentration in feathers. Transfer of an average of 80%–92% of the Hg in bodies to feathers
may have enhanced nestling survival. Residues of Hg in tissues of tree swallows in the Northeast seem higher than those of
the Midwest. 相似文献
853.
Bank MS Burgess JR Evers DC Loftin CS 《Environmental monitoring and assessment》2007,126(1-3):105-115
We reviewed literature reporting both total and methylmercury from biota from Acadia National Park, Maine, USA. Our review
of existing data indicates that 1) mercury contamination is widespread throughout the Park’s various aquatic ecosystems; 2)
mercury pollution likely represents a moderate to high risk to biota inhabiting the Park; and 3) biota at all trophic levels
possess elevated concentrations of both total and methylmercury. Watershed fire history and the resulting post-fire forest
succession patterns are an important landscape attribute governing mercury cycling at Acadia National Park. Therefore, park
service personnel should consider these factors when planning and implementing Hg biomonitoring efforts. Additional baseline
funding from the National Park Service for Hg research and biomonitoring will likely be required in order to further evaluate
the spatial and temporal patterns of mercury contamination in the park’s biota.
An erratum to this article can be found at 相似文献
854.
Johnson KB Haines TA Kahl JS Norton SA Amirbahman A Sheehan KD 《Environmental monitoring and assessment》2007,126(1-3):55-67
Throughfall and bulk precipitation samples were collected for two watersheds at Acadia National Park, Maine, from 3 May to
16 November 2000, to determine which landscape factors affected mercury (Hg) deposition. One of these watersheds, Cadillac
Brook, burned in 1947, providing a natural experimental design to study the effects of forest type on deposition to forested
watersheds. Sites that face southwest received the highest Hg deposition, which may be due to the interception of cross-continental
movement of contaminated air masses. Sites covered with softwood vegetation also received higher Hg deposition than other
vegetation types because of the higher scavenging efficiency of the canopy structure. Methyl mercury (MeHg) deposition was
not affected by these factors. Hg deposition, as bulk precipitation and throughfall was lower in Cadillac Brook watershed
(burned) than in Hadlock Brook watershed (unburned) because of vegetation type and watershed aspect. Hg and MeHg inputs were
weighted by season and vegetation type because these two factors had the most influence on deposition. Hg volatilization was
not determined. The total Hg deposition via throughfall and bulk precipitation was 9.4 μg/m2/year in Cadillac Brook watershed and 10.2 μg/m2/year in Hadlock Brook watershed. The total MeHg deposition via throughfall and bulk precipitation was 0.05 μg/m2/year in Cadillac Brook watershed and 0.10 μg/m2/year in Hadlock Brook watershed. 相似文献
855.
856.
无汞开管法快速测定工业废水中的COD 总被引:1,自引:0,他引:1
采用无汞开管法测定 COD。方法使用硫酸 -磷酸介质、重铬酸钾氧化体系 ,以硫酸银作催化剂 ,其他试剂包括硝酸银和硫酸铬钾以排除氯离子的干扰。样品在玻璃试管中进行消化 ,用一台恒温器加热样品 ,反应温度 1 65℃ ,加热时间只需 1 0 min,消解后剩余的重铬酸盐用分光光度法或滴定法测定。试验结果表明 ,本法的检出限为 1 0 .9mg/ L,测定范围为 3 0~ 1 5 0 0 mg/ L。由于方法不使用剧毒的汞盐 ,也就避免了汞对环境的污染。应用本法测定了大批量工业废水样品 ,结果令人满意 相似文献
857.
Mercury presents a potential risk to the environment and humans, especially in its methylated form. It is among the highest priority environmental pollutants. River Idrijca (Slovenia) is highly contaminated with mercury due to past mercury mining. The aim of this work was to investigate whether the periphyton community in rivers such as Idrijca is a suitable indicator of Hg pollution and of changes in mercury methylation and could serve as an early warning system of increased input of MeHg in the food chain. Periphyton is the only site of primary production in temperate torrential rivers such as Idrijca and is therefore an important link in the food chain. It is also a potential site of Hg accumulation and its introduction to higher trophic levels. Our aim was to assess the response of the periphyton to seasonal and spatial variations in mercury levels and to evaluate its potential as an early warning system of changes in mercury reactivity and mobilization The results indicate that periphyton in a torrential river is too complex and unpredictable to be used as a sole indicator of mercury concentrations and changes in the river. Nevertheless, it can complement environmental measurements due to its importance in the riverine food web. 相似文献
858.
859.
860.
汞的毒性、环境行为、生物有效性不仅跟其浓度有关,还决定于其化学形态,因此汞的形态分析在环境科学中具有重要意义。样品前处理几乎是汞形态分析研究中不可或缺的步骤,而色谱和光谱/质谱联用技术是目前普遍采用的分离检测方法。文章对近十年来这些方面的研究进展进行了综述,主要包括样品的前处理方法如酸/碱溶剂萃取、微波辅助萃取、固相萃取、固相微萃取、单滴微萃取、分散液液微萃取等,以及色谱(液相色谱、气相色谱)和毛细管电泳与光谱/质谱(紫外可见光谱、原子吸收光谱、原子荧光光谱、等离子体质谱等)的联用技术在汞化合物形态分析中的应用情况。最后提出今后应重点研究建立高效、简便的前处理方法,发展高分离度、高灵敏度、高速度的分离检测联用技术,以便更好地对汞的形态进行分析监测。 相似文献