Advanced Materials Research Vols. 634-638

Abstract: In order to find out a method of computation on the viscosity of CaF₂-SiO₂-Al₂O₃-CaO-MgO slag system, which is accurate, rapid and convenient, a systematic study has been carried out. The refining slag samples have been made by the method of rotation-regression-orthogonal combination design during the test. When the temperature of the flux of the samples were 1600°C~1400°C, the experiment was performed by internal rotating cylinder method involving a spindle with the RTW-10 flux physical properties measuring apparatus in graphite crucible per 50°C, meanwhile, the viscosity of slag system were estimated by thermodynamic software FactSage per 50°C. Then, according to the viscosity results of calculation at 1600°C, the viscosity calculation equation was established, which was the relation of the mass fraction of every components and the value of the slag viscosity. Furthermore, the interaction of two components on the influence of the viscosity of slag was discussed.

Abstract: The global-minimum geometries and electronic states of AgnH2S (n=1-5) clusters have been calculated using density-functional theory. Our calculations predicate that the stable geometries of AgnH2S clusters can be got by directly adding the H2S molecule on different site of Agn clusters, Agn (n=1-5) clusters would like to bond with sulfur atom and the H2S molecule is partial to hold the top location and single fold coordination site in the clusters. After adsorption, the structures of Agn clusters and H2S molecule keep the original structures and are only distorted slightly. The averaged binding energy reveals that adsorption of H2S molecule can strengthen the stabilities of AgnH2S clusters. The second difference in energy and the energy gaps between the HOMO and LUMO of Agn and AgnH2S have been studied.

Abstract: According to the electric field intensity of ten-needle electrodes (OTNE) in vacuum, the discrete equations based on the indetermination linear current density were established by the boundary element integral equations (BEIE). The non-uniform distribution of the current flowing from ten-needle electrodes to conductive in vacuum was imaged by solving a set of linear equations. Then, the electric field intensity generated by OTNE in vacuum at any point can be determined through the boundary element method (BEM). It means that this method has an important referenced significance for computing the electric field intensity generated by OTNE in vacuum

Abstract: Three indophenol blue methods have been used to analyze ammounium-N in five typical soils in China. Method I and II, using the same catalyst of sodium nitroprusside but different quantity and types of reagents, are suggested by Soil Science Society of America (SSSA) and Soil Science Society of China (SSSC), respectively. Method III adopts acetone as the catalyst. It was shown that three methods yielded similar ammonium-N contents with each type of soil. But the use of sodium nitroprusside resulted in higher experimental sensitivity; and Method II by SSSC was recommended due to its lower cost.

Abstract: A catalytic voltammetric method for the determination of vanadium(V) at a multi-wall carbon nanotube paste electrode (MWCNT-PE) in a 4-(2-pyridylazo)-resorcinol(PAR)-bromate system is proposed. The voltammetric response of V(V)-PAR complex at MWCNT-PE was significantly enhanced because of a catalytic cycle consisting of electrochemical reduction of V(V) ion in the complex and subsequent chemical oxidation of the reduction product of V(V) by bromate. In pH 2.70 H2SO4 solution containing 5.0×10-6 mol•L-1 PAR and 3.0×10-2 mol•L-1 KBrO3 without any preconcentration, the linear sweep voltammetric peak current of the catalytic wave was proportional to the vanadium concentration in the range of 8.0×10-9 to 3.0×10-6 mol•L-1. The detection limit was 2.5×10-9 mol•L-1. Using the proposed method, the vanadium concentration in crude oil was evaluated and the results were compared with those of atomic absorption spectrometry.

Abstract: Electrochemical behaviors of chalcopyrite, covellite, chalcocite and bornite in 9K medium at 65 °C were compared in this paper to verify they whether or not the intermediate products of chalcopyrite. The results confirmed that bornite, chalcocite and covellite are the intermediate products of chalcopyrite. Chalcocite and bornite can both oxidize to covellite.

Abstract: Geo-accumulation Index and Enrichment Factor were applied in source apportionment of Changchun atmospheric particulate matter. By mutual comparison with the results respectively, explored the similarities and differences. The result shows that the Geo-accumulation index and Enrichment Factors likes Zn, Cd are more serious, meanwhile the urban dust, soil wind dust, coal dust are the mainly pollution sources of Changchun air pollution, both methods can make a scientific evaluation to the human impact of Changchun particulate pollution in the atmosphere, provide an important reference for atmospheric particulate matter source apportionment.

Abstract: The decolourization of dye wastewater by persulfate was studied using methylene blue as a model dye wastewater. Effects of several parameters, such as dose of oxidant, ionic strength, pH, temperature and UV irradiation, were investigated in detail. The results showed that the decolourization reaction of methylene blue by persulfate could be fitted to a pseudo-first order kinetics model. In addition, when the oxidant amount used is 2 times of methylene blue, pH 3.43 and reaction temperature for 60°C, after uv light under the irradiation of 20 min, methylene blue decolorization rate can reach more than 98%. The results are useful for the treatment of dye wastewater.

Abstract: In pH=5.70 B-R buffer solution, Na2WO4 and rhodamine 6G（R6G） could react with natural cytokinins of 6-benzylaminourine (6-BA) and kinetin (KT) and resulted in a great enhacement of synchronous light scattering (SLS) signals. This article first established the degree of polarized synchronous light scattering (P) based on the measurements of the polarized synchronous light scattering signals to distinguish two natural cytokinins of 6-BA and KT. Simultaneously based on the synchronous scattering spectrum and the double standard curve method, a novel method for simultaneous determination of 6-BA and KT was developed by SLS spectralmethod. The method was applied to simultaneous determination of 6-BA and KT in balsam pear skin and tomato skin with satisfactory results.

Abstract: The analytical method on sodium sulfide, sodium sulfite, sodium hydroxide and sodium thiosulfate in sodium polysulfide solution was studied in this paper. The questions in concealing sodium sulfite by formaldehyde and precipitating sodium sulfide by zine acetate, a common method reported in some papers before, was discussed. The improvement on concealing Na2SO3 by SrCl2 instead of formaldehyde and precipitating Na2S by Zn(OH)2 instead of Zn(Ac)2 and testing concentration of NaOH in the mixture, was studied. The results showed that new method is simpler, more rapid, more completely and accurate, the overwhelming reason being that it had no effect on stability of sodium polysulfide.