摘要：
The adsorption of chromium (VI) ions from aqueous solution by ethylenediamine-modified cross-linked magnetic chitosan resin (EMCMCR) was studied in a batch adsorption system. Chromium (VI) removal is pH dependent and the optimum adsorption was observed at pH 2.0. The adsorption rate was extremely fast and the equilibrium was established within 6-10 min. The adsorption data could be well interpreted by the Langmuir and Temkin model. The maximum adsorption capacities obtained from the Langmuir model are 51.813 mg g(-1), 48.780 mg g(-1) and 45.872 mg g(-1) at 293, 303 and 313 K, respectively. The adsorption process could be described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that film diffusion might be involved in the present case. Thermodynamic parameters revealed the feasibility, spontaneity and exothermic nature of adsorption. The sorbents were successfully regenerated using 0.1 N NaOH solutions. (C) 2010 Elsevier B.V. All rights reserved.
期刊：
Journal of Environmental Radioactivity,2010年101(6):504-508 ISSN：0265-931X
通讯作者：
Wang, Jing-song
作者机构：
[Wang, Jing-song; Bao, Zheng-lei; Xie, Shui-bo; Hu, Xin-jiang] Univ S China, Sch Urban Construct, Hengyang 421001, Hunan, Peoples R China.;[Wang, Jing-song; Xie, Shui-bo] Univ S China, Hunan Key Lab Pollut Control & Resource Reuse, Henyang 421001, Hunan, Peoples R China.;[Liu, Yun-guo; Hu, Xin-jiang] Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Hunan, Peoples R China.;[Wang, Jing-song] Univ S China, Sch Urban Construct, 28 W Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, Jing-song] Univ S China, Sch Urban Construct, 28 W Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
会议名称：
9th International Conference on Biogeochemistry of Trace Elements
会议时间：
JUL, 2007
会议地点：
Beijing, PEOPLES R CHINA
会议主办单位：
[Wang, Jing-song;Hu, Xin-jiang;Xie, Shui-bo;Bao, Zheng-lei] Univ S China, Sch Urban Construct, Hengyang 421001, Hunan, Peoples R China.^[Wang, Jing-song;Xie, Shui-bo] Univ S China, Hunan Key Lab Pollut Control & Resource Reuse, Henyang 421001, Hunan, Peoples R China.^[Hu, Xin-jiang;Liu, Yun-guo] Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Hunan, Peoples R China.
关键词：
Immobilized beads<&wdkj&>Aspergillus fumigatus<&wdkj&>Biosorption<&wdkj&>Uranium (VI)<&wdkj&>Pseudo-second order
摘要：
Biosorption of uranium (VI) ions by immobilized Aspergillus fumigatus beads was investigated in a batch system. The influences of solution pH, biosorbent dose, U (VI) concentration, and contact time on U (VI) biosorption were studied. The results indicated that the adsorption capacity was strongly affected by the solution pH, the biosorbent dose and initial U (VI) concentration. Optimum biosorption was observed at pH 5.0, biosrobent dose (w/v) 2.5%, initial U (VI) concentration 60 mg L(-1). Biosorption equilibrium was established in 120 min. The adsorption process conformed to the Freunlich and Temkin isothermal adsorption models. The dynamic adsorption model conformed to pseudo-second order model. (C) 2010 Elsevier Ltd. All rights reserved.
摘要：
An air-stable hypervalent organobismuth (III) perfluorooctanesulfonate was synthesized and characterized by spectroscopic and X-ray crystallographic techniques, and found to exhibit high catalytic efficiency towards one-pot Mannich-type reaction of ketones with aromatic aldehydes and aromatic amines in water. This catalyst also shows good recyclability and reusability. This catalytic system would provide a simple, efficient and 'green' avenue towards the synthesis of beta-amino ketones. (C) 2009 Published by Elsevier B.V.
摘要：
In order to investigate the mechanism of extracellular polymeric substances (EPS) influencing sludge characteristics, variations of extractable EPS from municipal sewage sludge by acid/alkaline pretreatment and gamma-ray irradiation were studied. The changes in constituents of EPS were analyzed by UV-vis spectra and SEM images. The effects of alkaline pretreatment and gamma-ray irradiation on the functional groups in EPS were investigated by Fourier transform infrared (FTIR) spectrometer. Results showed that the extractable EPS increased clearly with increasing irradiation dose from 0 to 15 kGy. UV-vis spectra indicated that a new absorption band from 240 nm to 300 nm existed in all irradiated samples, apart from acid condition. The results of FTIR spectroscopic analysis indicated that, irradiation influenced major functional groups in EPS, such as protein and polysaccharide, and these effects were clearer under alkaline condition. SEM images provided that after alkaline hydrolysis, gamma-ray irradiation was more effective in resulting in the sludge flocs and cells broken, compared with acid pretreatment (pH 2.50). (c) 2013 Published by Elsevier Ltd.
作者机构：
[Xie, Dong; Wang, Yun; Mo, Shunquan; Liao, Maili] Univ South China, Sch Urban Construct, Hengyang 421001, Peoples R China.;[Xie, Dong; Wang, Hanqing] Cent S Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Wang, Hanqing] Hunan Univ Commerce, Changsha 410205, Hunan, Peoples R China.
通讯机构：
[Xie, Dong] Univ South China, Sch Urban Construct, Hengyang 421001, Peoples R China.
关键词：
Capillary ceiling radiant cooling panel<&wdkj&>Distribution of temperature non-uniformity<&wdkj&>Cooling capacity<&wdkj&>CFD<&wdkj&>Numerical analysis
摘要：
Capillary ceiling radiant cooling panel is a high temperature cooling system, which could pose low energy consumption to meet thermal comfort requirements. A computational fluid dynamics (CFD) simulation study on heat transfer of chilled water flow in the capillary of ceiling radiant cooling panel was performed to attain surface temperature distributions and cooling capacities. Six influencing factors included chilled water inlet parameters, conditions of gypsum plaster and capillary mats structural parameters were considered to obtain the complicated relationships between capillary radiant panel conditions and heat transfer performance. The index of temperature non-uniformity coefficient was proposed to evaluate temperature profiles of ceiling panel surface. The results of the simulation were compared with the values depicted in ASHRAE Handbook and good agreement had been achieved. The average difference between simulation results and the values reported by ASHRAE handbook was within the region of 15%. The research results showed that temperature non-uniformity coefficient was negatively correlated with temperature of chilled inlet water (linear correlation), water velocity (correlation coefficient R = -0.85), and pipe diameter (correlation coefficient R = -0.93), but positively and linearly correlated with tube spacing. Cooling capacity was found to have negative linear correlation with temperature of chilled inlet water, covering thickness and tube spacing. (C) 2015 Elsevier Ltd. All rights reserved.
摘要：
Fe(II)-Al(III) layered double hydroxides (Fe-Al LDHs) were prepared by the sono-assisted precipitation method and used for the removal of uranium (VI) from aqueous solutions. The application of ultrasound in the Fe-Al LDHs preparation promoted the formation of the hydrotalcite-like phase and improved the adsorption capacity of U(VI). Batch experiments were carried out to investigate the influence of solid-to-solution ratio, initial U(VI) concentration, initial pH, contact time and temperature on the U(VI) removal process. The experimental results indicated that the removal process of U(VI) could be well described by the pseudo-second-order kinetic model. The equilibrium isotherm for U(VI) removal was fitted by the Langmuir model and the maximum adsorption capacity of Fe-Al LDHs was 113.64 mg/g at a temperature of 308 K. The thermodynamic parameters implied that the removal of U(VI) was essentially an endothermic process. The FT-IR, EDX and XPS results suggested that the removal mechanism involves combined adsorption-reduction processes. When the U(VI) ions absorbed onto the Fe-Al LDHs through physical adsorption, the Fe(II) in the structure of Fe-Al LDHs reduces U(VI) to U(IV) while Fe(II) was oxidized to Fe(III). (C) 2017 Elsevier B.V. All rights reserved.
摘要：
This study investigates the impact behavior of concrete beams using drop-weight facility. Different tups were used and varying drop weights and heights were applied. This study measures impact loads, mid-span accelerations, and strains at the top and bottom edges of the beam. To distinguish the inertial and bending components of impact forces, inertial force is formulated based on elastic beam theory. When the strain rate ranges between 0.1 s(-1) and 4 s(-1), rate effect is significant given corresponding dynamic increase factors ranging from 1.6 to 3.4. Finally, the equilibrium of momentum-impulse and energy conversion are examined. (C) 2014 Elsevier Ltd. All rights reserved.
摘要：
Taking the heterogeneity character of concrete into account, this paper presents an equivalent probabilistic model for failure study of concrete in which the heterogeneity of concrete is considered by assuming that the material properties conform to the Weibull distribution law and by using mesoscale mesh of finite elements. The study is divided into three parts. In the first part, a spatial correlation length factor is developed into the Weibull distribution formula so that the spatial correlation of local continuity of material properties can be considered. The second part presents a series of numerical analyses for investigating the size effect of self-compacting concrete (SCC) based on the equivalent probabilistic model, and a comparison is made between the simulation results and compression test measurements for illustrating the size effect on uniaxial compression strength and failure pattern of the SCC concerned. It is shown that the numerical model can provide reasonable predictions in the analysis of the size effect of SCC. In the final part, as an engineering application of the presented model, the damage and fracture behavior of the Koyna gravity dam during the 1967 earthquake are analyzed. Influences of concrete parameters on the crack pattern and failure modes of the dam prototype during the event are discussed. DOI: 10.1061/(ASCE)MT.1943-5533.0000179. (C) 2011 American Society of Civil Engineers.
关键词：
Dunkirk sediments<&wdkj&>lime<&wdkj&>compressive strength behaviour<&wdkj&>shear strength test<&wdkj&>compressibility<&wdkj&>triaxial test
摘要：
The increasing cost associated with high-quality materials has lead to the need for sediments to be treated and then used in road construction in the context of durable development. Therefore, the modification and stabilisation of Dunkirk marine sediments by using lime is necessary to study for their potential use in road construction. Based on the physical characteristics of untreated sediments, a series of laboratory tests to investigate the geotechnical properties of untreated sediments and lime-treated sediments, such as unconfined compressive strength tests, standard oedometer tests, direct shear tests and triaxial tests, were performed. Lime was added in percentages of 3% and 6%, by weight of dry sediments. The test results show a significant improvement in unconfined compressive strength and shear strength due to the addition of lime. From the strain–stress relationship of compressive strength tests, it can be found that the failure mode of solidified sediments develops gradually from plastic failure to brittle failure, while the failure strength increases and the failure strain decreases with lime content. Compared with untreated sediments, the shear strength parameters of solidified sediments determined by direct shear tests, such as internal friction angle and cohesion, are increased owing to the pozzolanic reaction between lime and clay minerals. Using the oedometer apparatus, it is observed that after lime treatment, the preconsolidation pressure, the coefficient of consolidation and the compression index are increased, while the swelling index is decreased. The characteristics of the deviator stress–axial strain relation and the pore water pressure distribution under different confining stresses are compared with untreated and treated sediments, and the effect of lime content on cohesion and internal friction angle determined by triaxial tests is discussed.
期刊：
International Conference on Nuclear Engineering, Proceedings, ICONE,2010年133(8):84502-1-84502-3 ISSN：0742-4795
通讯作者：
Wang, Jing-song
作者机构：
[Wang, Jing-song; Bao, Zheng-lei; Chen, Si-guang] Univ South China, Hunan Key Lab Pollut Control & Resource Reuse, Sch Urban Construct, Hengyang 421001, Hunan, Peoples R China.;[Yang, Jin-hui] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, Jing-song] Univ South China, Hunan Key Lab Pollut Control & Resource Reuse, Sch Urban Construct, Hengyang 421001, Hunan, Peoples R China.
会议名称：
18th International Conference on Nuclear Engineering (ICONE-18)
会议时间：
MAY 17-21, 2010
会议地点：
Xian, PEOPLES R CHINA
会议主办单位：
[Wang, Jing-song;Bao, Zheng-lei;Chen, Si-guang] Univ South China, Hunan Key Lab Pollut Control & Resource Reuse, Sch Urban Construct, Hengyang 421001, Hunan, Peoples R China.^[Yang, Jin-hui] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.
关键词：
uranium;aqueous;chitosan;ferrous;discharge standard
摘要：
This study focuses on developing a new method to remove uranium from aqueous solution. Chitosan and ferrous ions were used together to remove uranium ions from aqueous solution. Through two-step pH adjustment, the uptake behavior of chitosan and ferrous ions toward uranium in aqueous solution using batch systems was studied in different experimental conditions. The experimental results indicated that the removal of uranium by the synergetic effect of chitosan and ferrous ions was more effective than the way of adsorbing uranium ions by chitosan alone. Under the given experimental conditions, the concentration of the residual uranium in the effluent after the chitosan and ferrous ion treatment could meet the discharge standard (< 0.05 mg l(-1)) when the initial concentration of uranium ions was 10 mg l(-1) or 100 mg l(-1). The synergetic effect of chitosan and ferrous ions, including adsorption, coacervation, and coprecipitation, was responsible for the high removal rate of uranium. [DOI: 10.1115/1.4002817]
摘要：
For sandwich beams with second-order hierarchical corrugated truss core under three-point bending, a correction factor of shear deflection was firstly proposed to improve the prediction accuracy of the bending analysis, which was verified by finite element analysis and compared with the original formula. Then, the failure modes of the sandwich beam under bending were analyzed, including four competing modes of the large struts (i.e. plastic yielding, buckling, wrinkling of facesheet, shear buckling) and two competing modes of the small struts (i.e. plastic yielding, buckling). Subsequently, the analytical expressions of critical load for each failure mode were derived. On this basis, the failure mechanism maps were constructed. Finally, several typical points from the map were selected and verified by finite element analysis, and a good agreement of predicted failure modes was observed.
