全文获取类型
收费全文 | 52篇 |
免费 | 1篇 |
专业分类
安全科学 | 1篇 |
环保管理 | 8篇 |
综合类 | 4篇 |
基础理论 | 23篇 |
污染及防治 | 10篇 |
评价与监测 | 3篇 |
社会与环境 | 1篇 |
灾害及防治 | 3篇 |
出版年
2018年 | 1篇 |
2016年 | 1篇 |
2015年 | 6篇 |
2013年 | 7篇 |
2012年 | 5篇 |
2011年 | 2篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2003年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1925年 | 2篇 |
排序方式: 共有53条查询结果,搜索用时 31 毫秒
41.
42.
Thomas Mehner Susan Busch Catriona Clemmesen Ingeborg Palm Helland Franz H?lker Jan Ohlberger Myron A. Peck 《Marine Biology》2012,159(11):2583-2603
Systematic comparisons of the ecology between functionally similar fish species from freshwater and marine aquatic systems are surprisingly rare. Here, we discuss commonalities and differences in evolutionary history, population genetics, reproduction and life history, ecological interactions, behavioural ecology and physiological ecology of temperate and Arctic freshwater coregonids (vendace and ciscoes, Coregonus spp.) and marine clupeids (herring, Clupea harengus, and sprat, Sprattus sprattus). We further elucidate potential effects of climate warming on these groups of fish based on the ecological features of coregonids and clupeids documented in the previous parts of the review. These freshwater and marine fishes share a surprisingly high number of similarities. Both groups are relatively short-lived, pelagic planktivorous fishes. The genetic differentiation of local populations is weak and seems to be in part correlated to an astonishing variability of spawning times. The discrete thermal window of each species influences habitat use, diel vertical migrations and supposedly also life history variations. Complex life cycles and preference for cool or cold water make all species vulnerable to the effects of global warming. It is suggested that future research on the functional interdependence between spawning time, life history characteristics, thermal windows and genetic differentiation may profit from a systematic comparison of the patterns found in either coregonids or clupeids. 相似文献
43.
Myron P. Zalucki Stephen B. Malcolm Christopher C. Hanlon Timothy D. Paine 《Chemoecology》2012,22(2):75-88
Growth rate and survival of first-instar larvae of Danaus plexippus, a milkweed specialist, depended on milkweed species, and was related to the amount of latex produced from wounds, leaf cardenolide
concentrations and the presence of leaf hairs. Larval growth was more rapid and survival was higher on leaves of Asclepias californica with experimentally reduced latex, and this species has characteristically high latex, low- to mid-range cardenolide concentrations,
and very hirsute leaves. Similarly, growth was higher on reduced latex leaves of both A. eriocarpa (a high latex/high cardenolide, hirsute species) and A. erosa (glabrous fleshy leaves, high latex/high cardenolides). There were no differences in either survival or growth rate between
larvae on reduced latex or control leaves of the low latex/low cardenolide A. fascicularis with soft glabrous leaves and both survival and growth rate were higher on this species than the other species tested. Larval
growth rates on leaves with reduced latex were similar among ten milkweed species tested to date but differed from growth
rates on intact leaves suggesting that latex and possibly included cardenolides are both important in first-instar monarch
larval growth, development and survival. We show for a range of ecologically important milkweeds that experiments on cut plant
material (no latex outflow) lead to higher growth rates compared to intact plants. Such laboratory assays based on detached
leaves will be misleading if the objective is to determine the impact of treatments such as Bt-maize pollen on monarchs on field plants. 相似文献
44.
Studies of the long-term impacts of acidic deposition in Europe and North America have prompted growing interest in understanding the dynamics linking the nitrogen (N) and calcium (Ca) cycles in forested watersheds. While it has been shown that increasing concentrations of nitrate (NO3-) through atmospheric deposition or through nitrification can increase Ca loss, the reciprocal effects of Ca on N transformation processes have received less attention. We studied the influence of soil Ca availability on extractable inorganic N (NO3- + NH4+) across a Ca gradient in the Adirondack Mountains, New York, USA. Our results did not show the direct Ca-N interaction that we had expected, but instead showed that exchangeable Ca coupled with soil moisture, soil organic matter, and ambient temperature accounted for 61% of the variability in extractable inorganic N across 11 sites over two growing seasons. Soil Ca concentrations were, however, positively related to sugar maple (Acer saccharum) and American basswood (Tilia americana) basal areas and negatively related to American beech (Fagus grandifolia) basal area. Based on litter chemistry differences among these tree species and reported potential N mineralization values, we suggest that the influence of Ca on soil inorganic N is through a multistep pathway: reciprocal interactions between soil Ca concentrations and species composition, which in turn affect the quality of litter available for N mineralization. If chronic soil Ca depletion continues, as reported in some forested ecosystems, potential shifts in biotic communities could result in considerable alterations of N cycling processes. 相似文献
45.
Sulfate () concentrations and fluxes were studied for multiple storm events in the Point Peter Brook watershed, a glaciated, forested
watershed located in Western New York, USA. Investigations were performed across one large (696 ha) and three small (1.6–3.4 ha)
catchments with varying extent of riparian and wetland areas. Concentrations of in groundwater sources (mean values: 238–910 μmolc L−1) were considerably greater than concentrations recorded for rainfall (60 μmolc L−1) and throughfall (72–129 μmolc L−1). Seasonality in concentrations was most pronounced for valley-bottom riparian waters with maximum concentrations in late winter–spring (February–March)
and a minimum in late summer (August). Concentrations of in wetland water were considerably less than riparian water indicating the likelihood of reduction in anoxic wetland conditions. Storm events displayed a dilution pattern in concentrations with a minimum coinciding with the maximum in throughfall contributions. End member mixing analysis (EMMA)
was able to predict the storm event concentrations of for four of the six comparisons. Concentrations of at the outlet of the large (696 ha) catchment were much greater than values recorded for the smaller catchments. Exports
of in streamflow exceeded the inputs from atmospheric deposition suggesting that watersheds like Point Peter Brook may not show
any immediate response to decreases in atmospheric deposition. 相似文献
46.
Shreeram Inamdar Julia Rupp Myron Mitchell 《Journal of the American Water Resources Association》2008,44(6):1458-1473
Abstract: Differences in the storm‐event responses of dissolved organic carbon (DOC) and nitrogen (DON) in streamflow and ground water were evaluated for a glaciated forested watershed in western New York. Eight to ten storm events with varying rainfall amounts, intensities, and antecedent moisture conditions were studied for three catchments (1.6, 3.4, and 696 ha) over a three‐year period (2003‐2005). Concentrations of DOC in streamflow exiting the catchments were significantly higher for storm events following a dry period, whereas no similar response was observed for DON. Highest DON concentrations in streamflow were typically associated with storm events following wet antecedent moisture conditions. In addition to antecedent moisture conditions, DOC concentrations were also positively correlated with precipitation amounts, while DON did not reveal a consistent pattern. Streamwater and ground‐water concentrations of DOC during storm events were also strongly correlated with riparian ground‐water depths but a similar relationship was not observed for DON. Ground‐water DON concentrations were also more variable than DOC. We hypothesized that the differences in DOC and DON responses stemmed from the differences in catchment sources of these solutes. This study suggests that while DOC and DON are intrinsically linked as components of dissolved organic matter, their dynamics and exports from watersheds may be regulated by a different set of mechanisms and factors. Identifying these differences is critical for developing more reliable and robust models for transport of dissolved organic matter. 相似文献
47.
This study examined the relationship between environmental concern and ratings of acceptability of environmental impacts among visitors at two national park settings. Based on the concept of a social ecological paradigm shift, it was hypothesized that individuals with greater levels of environmental concern are less accepting of environmental impacts in national parks than individuals with lesser degrees of concern. Sample data came from Cape Lookout National Seashore (N=392) and Moores Creek National Battlefield (N=236), two national park units in the south-eastern U.S.A. Environmental concern was measured by the New Ecological Paradigm scale. Acceptability was measured by visitor responses to 25 items covering different types of environmental park impacts. Analysis of variance and Tukey's means comparison procedure were used to test for differences between groups defined by levels of environmental concern on impact acceptability. Significant relationships were found between environmental concern and 15 of the 25 specific impacts in the Cape Lookout sample and 13 significant relationships were found in the Moores Creek sample. However, the relationships between environmental concern and acceptability varied somewhat across the two samples. These findings suggested that individuals with greater environmental concern were less accepting (or tolerant) of certain types of park impacts, while individuals with lesser degrees of environmental concern were more accepting of certain park impacts. Differences across the study settings were attributed to the different orientations of park visitors between the two national park units and recency effects. While the data reported are preliminary, they should be informative for park management purposes, particularly in the determination of standards for park impacts. 相似文献
48.
49.
50.
Amarpreet Chahal John Bissett Owen Rowland Myron L. Smith S. Shea Miller 《Journal of environmental science and health. Part. B》2013,48(12):945-954
The capacity of two soil fungi, Trichoderma koningii and Penicillium janthinellum, to oxidize n-C10:0 and n-C11:0 fatty acids to CO2 and store intracellular lipids during growth is unknown. This article reports for the first time the metabolism of decanoic acid (DA, C10:0), undecanoic acid (UDA, n-C11:0), a mixture of the acids (UDA+DA) and a mixture of UDA+ potato dextrose broth (PDB) by T. koningii and P. janthinellum and their mixed culture. A control PDB complex substrate was used as a substrate control treatment. The fungal cultures were assayed for their capacity to: (1) oxidize n-C10:0 and n-C11:0 fatty acids to CO2 and (2) store lipids intracellularly during growth. On all four fatty acid substrates, the mixed T. koningii and P. janthinellum culture produced more biomass and CO2 than the individual fungal cultures. Per 150 mL culture, the mixed species culture grown on UDA+PDB and on PDB alone produced the most biomass (7,567 mg and 11,425 mg, respectively). When grown in DA, the mixed species culture produced the least amount of biomass (6,400 mg), a quantity that was lower than those obtained in UDA (7,550 mg) or UDA+DA (7,270 mg). Amounts of CO2 produced ranged from 210 mg under DA to 618 mg under PDB, and these amounts were highly correlated with biomass (r2 = 0.99). Fluorescence microscopy of stained lipids in the mixed fungal cell cultures growing during the exponential phase demonstrated larger fungal cells and higher accumulation of lipids in membranes and storage bodies than those observed during the lag and stationary phases. T. koningii and P. janthinellum grown on n-C10:0 and n-C11:0 fatty acids produced lower amounts of biomass and CO2, but stored higher amounts of intracellular lipids, than when grown on PDB alone. 相似文献