全文获取类型
收费全文 | 961篇 |
免费 | 32篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 52篇 |
废物处理 | 43篇 |
环保管理 | 255篇 |
综合类 | 82篇 |
基础理论 | 258篇 |
环境理论 | 2篇 |
污染及防治 | 200篇 |
评价与监测 | 67篇 |
社会与环境 | 34篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 14篇 |
2018年 | 20篇 |
2017年 | 21篇 |
2016年 | 28篇 |
2015年 | 30篇 |
2014年 | 26篇 |
2013年 | 60篇 |
2012年 | 58篇 |
2011年 | 58篇 |
2010年 | 40篇 |
2009年 | 60篇 |
2008年 | 68篇 |
2007年 | 60篇 |
2006年 | 56篇 |
2005年 | 32篇 |
2004年 | 42篇 |
2003年 | 39篇 |
2002年 | 35篇 |
2001年 | 9篇 |
2000年 | 15篇 |
1999年 | 14篇 |
1998年 | 14篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 18篇 |
1993年 | 11篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1971年 | 1篇 |
1957年 | 2篇 |
排序方式: 共有1001条查询结果,搜索用时 15 毫秒
811.
Polycyclic aromatic hydrocarbons (PAH) were analyzed in surficial sediments and benthic organisms in southwestern Lake Erie near a large coal fired power plant. Sediment concentrations (530–770 ppb PAH) were relatively homogenous throughout most of the 150 km2 area, although river and nearshore concentrations reached nearly 4 ppm. Oligochaete worms and chironomid midges were near equilibrium with local sediments except for enhanced concentrations in nearshore midges. 相似文献
812.
813.
Estimating the aqueous solubility of aromatic hydrocarbons by high performance liquid chromatography
Empirical equations which correlate high performance liquid chromatography capacity factor (k′) to aromatic hydrocarbon aqueous solubility are developed. The correlations of k′ to octanol-water partition coefficients, and k′ to hydrocarbon surface area are also shown. 相似文献
814.
Callaghan TV Björn LO Chernov Y Chapin T Christensen TR Huntley B Ims RA Johansson M Jolly D Jonasson S Matveyeva N Panikov N Oechel W Shaver G Elster J Jónsdóttir IS Laine K Taulavuori K Taulavuori E Zöckler C 《Ambio》2004,33(7):418-435
Environmental manipulation experiments showed that species respond individualistically to each environmental-change variable. The greatest responses of plants were generally to nutrient, particularly nitrogen, addition. Summer warming experiments showed that woody plant responses were dominant and that mosses and lichens became less abundant. Responses to warming were controlled by moisture availability and snow cover. Many invertebrates increased population growth in response to summer warming, as long as desiccation was not induced. CO2 and UV-B enrichment experiments showed that plant and animal responses were small. However, some microorganisms and species of fungi were sensitive to increased UV-B and some intensive mutagenic actions could, perhaps, lead to unexpected epidemic outbreaks. Tundra soil heating, CO2 enrichment and amendment with mineral nutrients generally accelerated microbial activity. Algae are likely to dominate cyanobacteria in milder climates. Expected increases in winter freeze-thaw cycles leading to ice-crust formation are likely to severely reduce winter survival rate and disrupt the population dynamics of many terrestrial animals. A deeper snow cover is likely to restrict access to winter pastures by reindeer/caribou and their ability to flee from predators while any earlier onset of the snow-free period is likely to stimulate increased plant growth. Initial species responses to climate change might occur at the sub-species level: an Arctic plant or animal species with high genetic/racial diversity has proved an ability to adapt to different environmental conditions in the past and is likely to do so also in the future. Indigenous knowledge, air photographs, satellite images and monitoring show that changes in the distributions of some species are already occurring: Arctic vegetation is becoming more shrubby and more productive, there have been recent changes in the ranges of caribou, and "new" species of insects and birds previously associated with areas south of the treeline have been recorded. In contrast, almost all Arctic breeding bird species are declining and models predict further quite dramatic reductions of the populations of tundra birds due to warming. Species-climate response surface models predict potential future ranges of current Arctic species that are often markedly reduced and displaced northwards in response to warming. In contrast, invertebrates and microorganisms are very likely to quickly expand their ranges northwards into the Arctic. 相似文献
815.
The microbial role in hot spring silicification 总被引:8,自引:0,他引:8
Recent experimental studies indicate that microorganisms play a passive role in silicification. The organic functional groups that comprise the outer cell surfaces simply serve as heterogeneous nucleation sites for the adsorption of polymeric and/or colloidal silica, and because different microorganisms have different cell ultrastructural chemistry, species-specific patterns of silicification arise. Despite their templating role, they do not appear to increase the kinetics of silicification, and at the very most, they contribute only marginally to the magnitude of silicification. Instead, silicification is due to the polymerization of silica-supersaturated hydrothermal fluids upon discharge at the surface of the hot spring. Microorganisms do, however, impart an influence on the fabric of the siliceous sinters that form around hot spring vents. Different microorganisms have different growth patterns, that in turn, affect the style of laminations, the primary porosity of the sinter and the distribution of later-stage diagenetic cementation. 相似文献
816.
The measurement of roadway PM10 emission rates using atmospheric tracer ratio techniques 总被引:2,自引:0,他引:2
Ravi Kantamaneni Glen Adams Lee Bamesberger Eugene Allwine Hal Westberg Brian Lamb Candis Claiborn 《Atmospheric environment (Oxford, England : 1994)》1996,30(24):4209-4223
In this work, stationary and mobile point source tracer release techniques have been used to determine PM10 emission rates from four-lane commercial/residential paved roads under sanded and unsanded conditions, and from unpaved roads relative to site-specific vehicular and ambient parameters. Measured street (4 + lanes; ? 10,000 vehicles per day) emission factors for unsanded and sanded roads were 40 and 20% lower, respectively, than the EPA approved reference value. The sanded road emission factor was approximately 40% higher than that for the unsanded road. These results indicate a consistent relationship between PM10 and relative humidity under unsanded conditions. There is some evidence to suggest that street sweeping has a measurable effect on PM,, emission reduction during periods of low relative humidity (i.e. ? 30%). Within the constraints imposed by the variable experimental conditions, the emission factors determined for unpaved roads agreed reasonably well with the unpaved road empirical formula. Limited correlations were observed with ambient meteorological parameters. The capability of the “upwind-dowiawind” concentration modeling method to predict accurate emission was tested using a Gaussian dispersion model (SIMFLUX). Predictions agreed well with the experimentally determined emission factors. 相似文献
817.
818.
Brian A. Davies 《Environmental geochemistry and health》2001,23(1):79-84
Instructions for Authors
Environmental Geochemistry and Health 相似文献819.
Symmetric fights as a measure of escalation potential in a symbiotic,territorial snapping shrimp 总被引:1,自引:0,他引:1
Summary The shrimp Alpheus armatus territorially defends the sea anemone it occupies, using as a weapon its large, specially modified snapping claw. This behavior was studied in experimental contests which were symmetric (matched individuals) with respect to sex, size, and residency. Characteristics of these contests were compared for two size-classes of male and female shrimp.There were no significant differences between these groups of shrimp in the number of bouts required to establish dominance or in the number of snaps exchanged. Large females had shorter contests than either small or large males, and losers of contests between large females were injured more frequently and more severely.This distinctiveness of large female contests could be interpreted as evidence that (i) controlling anemones is more important for large females, (ii) injuries are less important for large females, or (iii) large females lose the ability to assess one another because their contests are less frequent.If injuries are an accurate measure of the most important costs associated with fighting, then these results indicate that short contests are not necessarily the least costly, and that females can be more aggressive than males, as measured by escalation potential, in sexually selected species. 相似文献
820.