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121.
At a rice-wheat rotational free-air CO2 enrichment(FACE) platform, the effect of elevated atmospheric CO2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO2 (ambient 370 μl/L 200 μl/L).32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effect of elevated atmospheric CO2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO2 may indicate the change of soil food web. 相似文献
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Ensegam A.M. Zohny 《环境科学学报(英文版)》2002,14(1):34-38
IntroductionInnatureCooccursintwooxidationstates ,Co2 + andCo3+ ,andformationofthecomplexanionCo(OH) - 3 isalsopossible .DuringweatheringCoisrelativelymobileinoxidizingacidenvironment,butduetoahighsorptionbyFeandMnoxides,aswellasbyclayminerals,thismetaldoesnotm… 相似文献
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《环境科学学报(英文版)》2023,35(3):553-567
Based on the online and membrane sampling data of Yuncheng from January 1st to February 12th, 2020, the formation mechanism of haze under the dual influence of Spring Festival and COVID-19 (Corona Virus Disease) was analyzed. Atmospheric capacity, chemical composition, secondary transformation, source apportionment, backward trajectory, pollution space and enterprise distribution were studied. Low wind speed, high humidity and small atmospheric capacity inhibited the diffusion of air pollutants. Four severe pollution processes occurred during the period, and the pollution degree was the highest around the Spring Festival. In light, medium and heavy pollution periods, the proportion of SNA (SO42−, NO3− and NH4+) was 59.6%, 56.0% and 54.9%, respectively, which was the largest components of PM2.5; the [NO3−]/[SO42−] ratio was 2.1, 1.5 and 1.7, respectively, indicating that coal source had a great influence; the changes of NOR (nitrogen oxidation ratio, 0.44, 0.45, 0.61) and SOR (sulphur oxidation ratio, 0.40, 0.49, 0.65) indicated the accumulation of secondary aerosols with increasing pollution. The coal combustion, motor vehicle, secondary inorganic sources and industrial sources contributed 36.8%, 26.59%, 11.84% and 8.02% to PM2.5 masses, respectively. Backward trajectory showed that the influence from the east was greater during the Spring Festival, and the pollutants from the eastern air mass were higher, which would aggravate the pollution. Meteorological and Spring Festival had a great impact on heavy pollution weather. Although some work could not operate due to the impact of the COVID-19 epidemic, the emission of pollutants did not reduce much. 相似文献
129.
Liu Zhenyu Yang Fenglin Quan Xie Zhang Xiaohong 《Frontiers of Environmental Science & Engineering in China》2007,1(2):166-171
A QWASI model dependent on temperature is parameterized to describe the long-term fate of persistent organic pollutants (POPs)
in the Liao River. The model parameters, namely fugacity capacity, degradation rate, and transfer coefficient, are profoundly
affected by temperature. This model is used to simulate the fate of γ-hexachlorocyclohexane (γ-HCH) in the lower reaches of the Liao River from 1998 to 2008. Modeling results show that γ-HCH fugacity capacities in air, water, and sediment increase as temperature decreases, and the transfer and transformation
rate coefficients increase as temperature increases. The variations of transfer and transformation parameter D values depend on fugacity capacities, and transfer and transformation coefficients simultaneously. The performance of the
model is evaluated by comparing the predicted and observed concentrations in the water and sediment of the Liao River. The
predicted values agree well with the observed value in the order of magnitude, in most cases within the factor of 3. It is
believed that the model is appropriate for simulating the long term fate of POPs in the Liao River.
Translated from Environmental Science, 2006, 27(1): 121–125 [译自: 环境科学] 相似文献
130.
Effects of acid deposition on forests in south China 总被引:1,自引:0,他引:1
1IntroductionWiththefastgrowingofmodernindustryandsharplyincreasingofenergyconsumptionprimarilycoal,airpolutionandaciddeposit... 相似文献