Sensitizing Mechanism and Adsorption Properties of Dye—Sensitized TiO2 Thin Films

The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces,and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were inverstigated.The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed.Experimental results show that the concentration,the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption.Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.     

Kinetic model for water/oil absorption of mesquite gum (Prosopis juliflora) and gum arabic (Acacia senegal)

The water and oil uptake of mesquite and arabic gums in powdered form was studied at temperatures of 23, 35 and 45°C. A previously proposed equation to predict osmotic equilibrium was tested using the experimental data with both gums and a good statistical fit was obtained. Mesquite gum showed the highest water and oil absorption at all temperatures studied. Temperature dependence of the reciprocal of the S₁ and WL_∞ were determined using an Arrhenius equation. The activation energy for water and oil absorption for gum arabic was 21.98 and 39.57 kJ mol⁻¹, compared to that of mesquite gum having values of 15.79 and 46.16 kJ mol⁻¹, respectively. A second order kinetic model was obtained for water and oil absorption for both gums.     

Influence of residual milk-clotting enzyme and proteolysis on melting properties of soft cheese

In this work, we assessed the influence of coagulant residual activity and primary proteolysis on Cremoso Argentino cheese melting properties. For that purpose, we made Cremoso soft cheeses using different amounts of coagulant, and also obtained samples in which milk-clotting enzyme was inactivated. Primary proteolysis correlated with residual activity of coagulant in early stages of cheese ripening; however, it was similar in all cheeses after 30 days. The hydrolysis of caseins did not significantly affect the melting ability of the cheeses, expressed as the area increase after heating samples under standardized conditions. Samples with similar proximate composition showed some changes in meltability; those seemed related to pH evolution during ripening.     

碘量法测铜中物质性质和分析操作

本文讨论了碘量法测定铜量中一些有关物质的特性,以及这些性质对分析条件和操作的要求。     

Water-soluble copolymers: 22. Copolymers of acrylamide with 2-acrylamido-2-methylpropanedimethylammonium chloride: Aqueous solution properties of a polycation

The viscometric, turbidimetric and potentiometric properties of copolymers of acrylamide (AM) with 2-acrylamido-2-methylpropanedimethylammonium chloride (AMPDAC) were studied in aqueous solutions. The AMPDAC polymers exhibit poor salt tolerance and large, negative viscosity/temperature coefficients. Furthermore, the polymers were found to be sensitive to changes in pH. The AMPDAC polymers undergo phase separation in the presence of dianions as a function of temperature and AMPDAC composition.     

La doping effects on intergrowth Bi2WO6–Bi3TiNbO9 ferroelectrics

La doping effects on intergrowth Bi₂WO₆–Bi₃TiNbO₉ ferroelectric ceramics were studied by X-ray diffraction, electron probe microanalysis and dielectric spectroscopy. It was found that the La³⁺ distribution, ferroelectric phase transition and dielectric relaxation behavior are apparently affected by La doping. With increasing La³⁺ content, the site of dopant ion varies, the grain growth of Bi₅TiNbWO₁₅ is restrained, the Curie temperature is reduced and broadened. Furthermore, two dielectric relaxation loss peaks were observed both in temperature and frequency spectra. The calculated relaxation parameters revealed the oxygen vacancy related to the relaxation process.     

Nucleation of copper on an assembly of carbon microelectrodes

The initial stage of copper electrodeposition on the electrochemically activated assembly of carbon microelectrodes from an acid solution of copper sulfate was investigated using cyclic voltammetry, potentiostatic pulse technique and electrochemical impedance spectroscopy. Analysis of the experimental current transients has been carried out using a non-linear fitting procedure according to the model that takes into account spherical diffusion towards a disc-shaped microelectrode. The higher values of diffusion coefficient in comparison with those observed on planar electrodes were explained with an increased diffusion caused by the electrode geometry. Impedance spectra showed two time constants, the high-frequency related to the charge transfer process and the low-frequency corresponded to the deposit morphology.     

VN合金在大规格角钢生产中的应用研究

大规格角钢主要用于铁塔制造和建筑结构中。唐钢过去用16Mn钢生产Q345级别角钢，因供轧化学成分范围较窄，供轧率偏低。通过加入V-Fe合金及VN合金进行微合金化，设计了16Mnv(N)钢种生产角钢，使角钢综合性能有显著提高。分析比较了16Mn、16MnV及16MnV(N)角钢的性能，认为在大规格高强度角钢生产中，用VN合金进行微合金化，其效果是最佳的。     

含钡合金的生产及其对钢液脱氧行为的研究

介绍了含钡合金的生产状况。在MoSi2炉上对钢管钢进行了含钡合金脱氧行为的研究，然后在150tLF／VD精炼设备上进行了使用含钡合金的工业试验。研究中主要选取SiAlBa、SiCaBa、SiAlBaCa、SiAlBaCaSr及用于钙处理的SiCa包芯线，并选用Al和FeSiAl作为对比脱氧剂，分别考察了实验室条件下和实际生产过程中，采用钡系合金对钢液脱氧的全氧含量，脱氧产物的分布、尺寸和形貌，探讨了钡系合金脱氧和对夹杂物的变质作用的机理。