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361.
Mohammad Goodarzi Erlinda V. Ortiz Leandro dos S. Coelho Pablo R. Duchowicz 《Atmospheric environment (Oxford, England : 1994)》2010,44(26):3179-3186
This work aims to predict the air to water partitioning for 96 organic pesticides by means of the Quantitative Structure–Property Relationships Theory. After performing structural feature selection with Genetics Algorithms and Replacement Method linear approaches, it is found that among the most important molecular features appears the Moriguchi octanol–water partition coefficient, and higher lipophilicities would lead to compounds having higher Henry’s law constants. We also compare the statistical performance achieved by four fully-connected Feed-Forward Multilayer Perceptrons Artificial Neural Networks. The statistical results found reveal that the best performing model uses the Levenberg–Marquardt with Bayesian regularization (BR) weighting function for achieving the most accurate predictions. 相似文献
362.
363.
Md. Abul Kashem Bal Ram Singh Hiroshi Kubota Reiko Sugawara Nobuyuki Kitajima Toshihito Kondo Shigenao Kawai 《Environmental science and pollution research international》2010,17(5):1174-1176
Background, aim, and scope
Zinc is an essential micronutrient element but its concentrations found in contaminated soils frequently exceed those required by the plant and soil organisms, and thus create danger to animal and human health. Phytoremediation is a technique, often employed in remediation of contaminated soils, which aims to remove heavy metals or other contaminants from soils or waters using plants. Arabidopsis (A.) halleri ssp. gemmifera is a plant recently found to be grown vigorously in heavy metal contaminated areas of Japan and it contained remarkably high amount of heavy metals in its shoots. However, the magnitude of Zn accumulation and tolerance in A. halleri ssp. gemmifera need to be investigated for its use as a phytoremediation plant. 相似文献364.
Peter R. Claggett Judy A. Okay Stephen V. Stehman 《Journal of the American Water Resources Association》2010,46(2):334-343
Claggett, Peter R., Judy A. Okay, and Stephen V. Stehman, 2010. Monitoring Regional Riparian Forest Cover Change Using Stratified Sampling and Multiresolution Imagery. Journal of the American Water Resources Association (JAWRA) 46(2):334-343. DOI: 10.1111/j.1752-1688.2010.00424.x Abstract: The Chesapeake Bay watershed encompasses 165,760 km2 of land area with 464,098 km of rivers and streams. As part of the Chesapeake Bay restoration effort, state and federal partners have committed to restoring 26,000 miles (41,843 km) of riparian forest buffers. Monitoring trends in riparian forest buffers over large areas is necessary to evaluate the efficacy of these restoration efforts. A sampling approach for estimating change in riparian forest cover from 1993/1994 to 2005 was developed and implemented in Anne Arundel County, Maryland, to exemplify a method that could be applied throughout the Bay watershed. All stream reaches in the county were stratified using forest cover change derived from Landsat imagery. A stratified random sample of 219 reaches was selected and forest cover change within the riparian buffer of each sampled reach was interpreted from high-resolution aerial photography. The estimated footprint of gross change in riparian forest cover (i.e., the sum of gross gain and gross loss) for the county was 1.83% (SE = 0.22%). Stratified sampling taking advantage of a priori knowledge of locations of change proved to be a practical and efficient protocol for estimating riparian forest buffer change at the county scale and the protocol would readily extend to much broader scale monitoring. 相似文献
365.
Janya L. Kelly Diane V. Michelangeli Paul A. Makar Donald R. Hastie Michael Mozurkewich Janeen Auld 《Atmospheric environment (Oxford, England : 1994)》2010,44(3):361-369
A kinetically based gas-particle partitioning box model is used to highlight the importance of parameter representation in the prediction of secondary organic aerosol (SOA) formation following the photo-oxidation of toluene. The model is initialized using experimental data from York University's indoor smog chamber and provides a prediction of the total aerosol yield and speciation. A series of model sensitivity experiments were performed to study the aerosol speciation and mass prediction under high NOx conditions (VOC/NOx = 0.2). Sensitivity experiments indicate vapour pressure estimation to be a large area of weakness in predicting aerosol mass, creating an average total error range of 70 μg m?3 (range of 5–145 μg m?3), using two different estimation methods. Aerosol speciation proved relatively insensitive to changes in vapour pressure. One species, 3-methyl-6-nitro-catechol, dominated the aerosol phase regardless of the vapour pressure parameterization used and comprised 73–88% of the aerosol by mass. The dominance is associated with the large concentration of 3-methyl-6-nitro-catechol in the gas-phase. The high NOx initial conditions of this study suggests that the predominance of 3-methyl-6-nitro-catechol likely results from the cresol-forming branch in the Master Chemical Mechanism taking a significant role in secondary organic aerosol formation under high NOx conditions. Further research into the yields and speciation leading to this reaction product is recommended. 相似文献
366.
S. Alfieri U. Amato M.F. Carfora M. Esposito V. Magliulo 《Atmospheric environment (Oxford, England : 1994)》2010,44(15):1866-1876
Quantifying trace gas emissions and the influence of surface exchange processes on the atmosphere is a necessary step towards the control of global greenhouse gas emissions and reliability of air quality models. This paper proposes a procedure based on the mass balance method and implemented on highly resolved aircraft data. It allows one to estimate surface exchanges on areas of several km2 and heterogeneous features exploiting the characteristics of convective boundary layer during steady state conditions that permit the estimation of emission/absorption terms as functions of advective fluxes only. A nonparametric approach is adopted and the fluxes on the surface of a virtual box surrounding the area of interest are reconstructed on the basis of scalar densities and wind vectors using Shepard functions. Two different techniques are also proposed to face lack of data on the top surface of the box. The method has been applied to experimental data coming from measurement campaigns on two different sites. It provides realistic estimates of the CO2 emission/absorption in the considered areas that are in good agreement with CO2 fluxes evaluated by Airborne Eddy Covariance and confirm the suitability of the proposed approach for the assessment of turbulent exchange of trace gases by composite landscapes. Uncertainties on the estimated emissions due to both propagation of the experimental error and interpolation have been quantified by bootstrap analysis as 6%. 相似文献
367.
368.
The effect of invertebrate predation pressure by the cladoceran Leptodora kindti on the population structure of Daphnia galeata and D. hyalina has been estimated by analyzing the occurrence frequency of the normal and spined morphotypes in Lake Baikal. It is shown
that the growth of L. kindti population density leads to an increase in the proportion of the spined morphotype, while that of that of the normal morphotype
decreases. 相似文献
369.
V. N. Orlov Yu. M. Borisov S. Yu. Irkhin A. A. Kovaleva 《Russian Journal of Ecology》2010,41(6):519-523
The distribution of three chromosome races (Moscow, Western Dvina, and Seliger) of the common shrew Sorex araneus L. in the zone of contact between their ranges in the Valdai Heights (32°00′ E, 57°00′ N) is discussed. The area co-inhabited
by all the three races is extremely small. Representatives of all the three races have been captured on only one trap line,
although there are no obstacles to the expansion of shrews. The extremely small area co-inhabited by the three races, as well
as the strictly parapatric distribution of the Moscow and Western Dvina races, may be related with competition forms such
as avoidance of contacts and separation of ecological niches. 相似文献
370.
Using the long-tailed tit (Aegithalos c. caudatus) as an example of the so-called irruptive species, the ecophysiological characteristics (body mass, fat reserves) and migration
speed during autumn period were analyzed. The mean body mass and the median fat score did not depend on the number of migrating
individuals. There was no evidence of the so-called stress in birds, participating in migration: migrants had even higher
fat reserves than residents, while no significant difference in the body mass was recorded. The increase in fat reserves in
the long-tailed tit during migration period was similar to the seasonal changes in energy reserves known for typical migrants.
This makes it possible for late-migrating individuals to maintain higher total speed of migration compared to early-migrating
ones. Basing on the obtained data, we conclude that the ecophysiological characteristics of the long-tailed tits migrating
in autumn are similar to those of regular migrants. 相似文献