排序方式: 共有24条查询结果,搜索用时 846 毫秒
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Callaghan Terry V. Kulikova Olga Rakhmanova Lidia Topp-Jørgensen Elmer Labba Niklas Kuhmanen Lars-Anders Kirpotin Sergey Shaduyko Olga Burgess Henry Rautio Arja Hindshaw Ruth S. Golubyatnikov Leonid L. Marshall Gareth J. Lobanov Andrey Soromotin Andrey Sokolov Alexander Sokolova Natalia Filant Praskovia Johansson Margareta 《Ambio》2020,49(6):1161-1178
Ambio - The Circumpolar North has been changing rapidly within the last decades, and the socioeconomic systems of the Eurasian Arctic and Siberia in particular have displayed the most dramatic... 相似文献
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Novel catalytic nano-sized materials based on LaCoO(x) perovskite nanoparticles incapsulated in the mesoporous matrix of zirconia were prepared, characterized by physicochemical methods and tested in complete methanol oxidation. LaCoO(x) nanoparticles were prepared inside the mesopores of ZrO(2) by decomposition of bimetallic La-Co glycine precursor complexes. The catalysts have been studied by diffuse-reflectance FTIR-spectroscopy using such probe molecules as CO, CD(3)CN and CDCl(3) to test low-coordinated metal ions. At low temperatures of decomposition of complexes (up to 400°C), low-coordinated Co(3+) ions predominate in the LaCoO(x) nanoparticles, whereas basically Co(2+) ions are found upon increasing the decomposition temperature to 600°C. The novel nano-sized perovskite catalysts exhibit a very high catalytic activity in the abatement of volatile organic compounds present in air, like methanol and light hydrocarbons. 相似文献
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This paper presents a hybrid model for transport in connected macro-pores in porous media. A pore-scale model is used to parameterize the hybrid model. The hybrid model explicitly models the advection and diffusion of species in the connected macro-pores and treats the porous media around the connected macro-pores as a continuum with effective transport properties. The pore-scale model is used to calculate the effective transport properties of the porous continuum. This approach negates the need to calibrate the hybrid model against experimental data, which is common for continuum-scale models of porous media, and allows an arbitrary microstructure to be considered. The paper presents the multi-scale modeling approach along with the details of the hybrid and pore-scale models. Validation of the model is also presented along with several case studies investigating the applicability of the multi-scale modeling approach to different geometries and transport conditions. The case studies show that the multi-scale modeling approach is accurate for various connected macro-pore geometries given that the porosity of the porous medium around the connected macro-pores is sufficiently small. The accuracy of the hybrid model decreases with increasing porosity of the matrix. 相似文献
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Boris Tartakovsky Yehuda Kleiner Michelle-France Manuel 《Environmental science and pollution research international》2018,25(33):32844-32850
This study describes a novel wastewater treatment technology suitable for small remote northern communities. The technology is based on an enhanced biodegradation of organic carbon through a combination of anaerobic methanogenic and microbial electrochemical (bioelectrochemical) degradation processes leading to biomethane production. The microbial electrochemical degradation is achieved in a membraneless flow-through bioanode–biocathode setup operating at an applied voltage below the water electrolysis threshold. Laboratory wastewater treatment tests conducted through a broad range of mesophilic and psychrophilic temperatures (5–23 °C) using synthetic wastewater showed a biochemical oxygen demand (BOD5) removal efficiency of 90–97% and an effluent BOD5 concentration as low as 7 mg L?1. An electricity consumption of 0.6 kWh kg?1 of chemical oxygen demand (COD) removed was observed. Low energy consumption coupled with enhanced methane production led to a net positive energy balance in the bioelectrochemical treatment system. 相似文献
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Christina Vakh Ekaterina Evdokimova Alexey Pochivalov Leonid Moskvin Andrey Bulatov 《毒物与环境化学》2017,99(4):613-623
The novel and simple methods for the sensitive determination of cationic and anionic surfactants in water based on effervescence assisted dispersive liquid–liquid microextraction and microvolume UV-Vis spectrophotometry have been developed. The method involves ion-pair extraction of cationic and anionic surfactants with organic dyes (methyl orange and azure A, respectively) during the dispersion of extraction solvent (CHCl3) by CO2 bubbles which are formed by the injection of a mixture of the extraction solvent and proton donor solvent into the sample solution which contains carbonate-ions as effervescency agent. The analytical performance of the proposed procedure was compared with the conventional dispersive liquid–liquid microextraction. Appropriate experimental conditions for both methods were investigated. The absorbances of the colored extracts at wavelengths of 440 and 625 nm obey Beer's law within the range of 0.1–5.0 mg/L for both cationic and anionic surfactants. The limit of detection (LOD) obtained using the effervescence assisted extraction method was 30 µg/L for cationic and anionic surfactants. The proposed methods were successfully applied to determination of surfactants in water samples. 相似文献
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Minori Uchimiya Leonid Gorb Mohammad M. Qasim 《Environmental pollution (Barking, Essex : 1987)》2010,158(10):3048-3053
Extensive studies have been conducted in the past decades to predict the environmental abiotic and biotic redox fate of nitroaromatic and nitramine explosives. However, surprisingly little information is available on one-electron standard reduction potentials (Eo(R-NO2/R-NO2−)). The Eo(R-NO2/R-NO2−) is an essential thermodynamic parameter for predicting the rate and extent of reductive transformation for energetic residues. In this study, experimental (linear free energy relationships) and theoretical (ab initio calculation) approaches were employed to determine Eo(R-NO2/R-NO2−) for nitroaromatic, (caged) cyclic nitramine, and nitroimino explosives that are found in military installations or are emerging contaminants. The results indicate a close agreement between experimental and theoretical Eo(R-NO2/R-NO2−) and suggest a key trend: Eo(R-NO2/R-NO2−) value decreases from di- and tri-nitroaromatic (e.g., 2,4-dinitroanisole) to nitramine (e.g., RDX) to nitroimino compound (e.g., nitroguanidine). The observed trend in Eo(R-NO2/R-NO2−) agrees with reported rate trends for reductive degradation, suggesting a thermodynamic control on the reduction rate under anoxic/suboxic conditions. 相似文献
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