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Yang Y.,Tsinghua University | Shao X.,Tsinghua University | Zhou G.,China Research Academy of Environmental science | Qin C.,Tsinghua University
Qinghua Daxue Xuebao/Journal of Tsinghua University | Year: 2015

30 surface water environmental quality models in the literatures were analyzed to classify model indicators according to the research topic, assessment criteria, and operation grade. Some features of these models such as model development, functional diversity, methodological diversity and application were used to develop an assessment system for hydrodynamic models while the classification variable was the research topic. An application of the ELCIRC model showed that the ELCIRC model does well. ©, 2015, Press of Tsinghua University. All right reserved. Source

Wei C.-Y.,Petrochina | Wang H.-T.,Petrochina | Zhao L.-N.,China Research Academy of Environmental science | Zhang S.-C.,Petrochina | Cheng L.,Petrochina
Bulletin of Mineralogy Petrology and Geochemistry | Year: 2012

Two groups of chloroform bitumen "A" samples were separated from some selected sedimentary rock samples using an accelerated solvent extraction apparatus (ASE300) and a fast Soxhlet extraction apparatus, respectively. The geochemical parameters of saturated hydrocarbons, aromatics, resin and asphaltene from the different chloroform bitumen "A" sample groups were systematically studied and compared. The experiment results showed that the obtained amounts of chloroform bitumen "A" are slightly higher using the ASE300 than using the fast Soxhlet in most cases, and that the main increments of using ASE300 are resin and asphaltene. GC-MS study indicated that saturated and aromatic hydrocarbons extracted from two groups of chloroform bitumen "A" samples are highly consistent, the deviations of the quantitative results are less than 5%, the differences of measured carbon stable isotope compositions for any identical component obtained respectively from two extraction methods fall into the range of ± 0.5‰. These results indicated that ASE300 and fast Soxhlet extracted instruments are comparative. Therefore, the ASE300, the relatively consumption saving and analytically efficient method, can replace the fast Soxhlet extraction apparatus in geochemical pretreatment experiments. Source

Huo T.,Agricultural University of Hebei | Bai S.,China Research Academy of Environmental science | Bai S.,Agricultural University of Hebei
Advanced Materials Research | Year: 2012

Through large-scale model tests on composite foundation of cement-soil piles under cyclic loading, a program was compiled based on the platform of MATLAB 7.0, considering the effects of cement mixing ratio, replacement ratio, cyclic stress ratio and number of cyclic on the permanent settlement of composite ground. A back-propagation neural network model to predict the settlement was established, and its prediction accuracy was inspected. Meanwhile, an predicting model of multivariable linear regression analysis was established .To compare the prediction accuracy of the two methods, and the result shows that the trained neural network have the better predictive and generalization. © (2012) Trans Tech Publications, Switzerland. Source

Liu M.,Shanghai Institute of Technology | Liu M.,Tongji University | Hou L.-A.,Tongji University | Xi B.-D.,China Research Academy of Environmental science | And 3 more authors.
Chemical Engineering Journal | Year: 2016

The magnetically separable Ag/AgCl - zero valent iron particles (ZVIP) impregnated zeolite X (Ag/AgCl/(x)Fe-ZX) photocatalysts were prepared for tetracycline (TC) degradation. The characterization results showed the Ag/AgCl/(x)Fe-ZX particles were spherical and crystalline Ag/AgCl was deposited on the surface of the (x)Fe-ZX. The spent Ag/AgCl/(x)Fe-ZX could be effectively separated from water due to the good magnetic property. When the content of the ZVIP increased, the photocatalytic efficiencies of Ag/AgCl/(x)Fe-ZX were increased. The photocatalytic efficiency of TC degradation was maximum as the weight ratio of ZVIP was 5%. The photocatalysts retained high photocatalytic activity after consecutive runs. The concentration of iron ions leaching was very low. The enhanced photocatalytic activities and stabilities of photocatalysts were ascribed to the enhanced adsorption capacity of (x)Fe-ZX, the strong absorbance in the visible-light region and improved space separation of photo-induced charge carriers. The study provides new insight into the preparation of stable and easily separated zeolite based heterogeneous photocatalysts. © 2016 Elsevier B.V. Source

An J.,CAS Institute of Atmospheric Physics | Xiang W.,CAS Institute of Atmospheric Physics | Han Z.,Chinese Academy of Sciences | Xiao K.,Tsinghua University | And 7 more authors.
Atmospheric Environment | Year: 2013

The urban canopy layer parameterization (UCP), a successive bias correction method (SBC), an atmospheric dispersion module for denser-than-air releases, and the emission intensity of chemicals monitored by a Fourier-transform-infrared remote sensor (EM27) were incorporated into the Institute of Atmospheric Physics emergency response model (IAPERM). IAPERM's performance was tested in Beijing using the field data collected from a 325-m meteorological tower and sulfur hexafluoride (SF6) diffusion and pool fire experiments. The results show that the IAPERM simulations of the vertical wind speeds in the urban canopy layer (UCL) with the UCP perform much better than those with the Monin-Obukhov similarity parameterization scheme. The IAPERM forecasts for air temperature and relative humidity are more accurate than those for wind speed and direction, which require correction. When the SBC with the local terrain effect is adopted, the wind speed and direction and the maximum concentrations of black carbon near the ground are well forecasted. IAPERM reproduces the spatial distributions of the SF6 observations more accurately near the release source (≤500m) than at locations far away from the release source with the use of the observed meteorological parameters. These results suggest that IAPERM could be a promising tool for passive and dense gas diffusion simulations or forecasts. © 2013 Elsevier Ltd. Source

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