Advanced Materials Research Vols. 430-432

Abstract: This paper studied experimental conditions of making higher absorption activated carbon from Jincheng anthracite. The result was obtained by using the orthogonal experiment in which four factors were designated: the carbonization temperature, the carbonization time, the activation time as well as the additive types, with the target of iodine value. The optimized parameters had been found out: the carbonization temperature is 600 °C，the carbonization time is 1.5 h, the activation time is 4 h and the additive is NaNO3 which is better in a weight proportion of 8 %. At last, under the optimized parameters, the better activated carbon products could be gained by acid pickling, which has a higher iodine value 1094.8 mg/g and low ash content 8.73 %.

Abstract: The formation reson of the surface defect of 0Cr18Ni10Ti after rolling is analyzed, some improving solutions are performed for avoiding the surface defect and enhancing the production quality. The investigation shows that the surface defect of rolled steel is mainly ascribed to the inclusions containing Ti, and TiO2 and TiN is a primary source of inclusions in the steel. An effective way of reducing the inclusion performed is decreasing the Ti and N content in liquid steel. By appropriately increasing the carbon content of molten steel entering into the AOD, decreasing the carbon content of the end of blasting oxygen, slag skimming in the ladle and slagging in LF furnace, feeding SiCa wire before Ti alloying in LF furnace and optimization of Ti alloying method and protection casting with no oxidation, the yield of Ti is greatly increased, the TiO2 and TiN inclusions is controlled better, the quality of products 0Cr18Ni10Ti all are greatly improved. The number of continuous casting furnace is increased from one to the three furnace, and the production efficiency is obviouly enhanced in TISCO.

Abstract: Ni60WC35 self-fluxing composite coating was fabricated by transverse-flow CO2 laser apparatus on 45 medium-carbon steel surfaces. The microstructure and phase transform behavior of WC reinforced particles under the laser cladding conditions was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). The results show that laser scanning speed has a great important influence on the microstructure of Ni-based WC composite coating, WC particles has a transition to the Ni-based coating. The main feature of WC particle is its edge hard phase has transformed into needle phase, and the needle phase areas increase with the decrease of the laser scanning speed. Some WC particles turn into needle clusters structure, and then white block phase. In addition, WC particle has some microscopic defects, and the surface priority defect can be dissolved. When the pool temperature rises to 1250°C, WC decomposition reaction become W2C and C. The elements diffusion can promote the dissolution of WC particles when the pool temperature rises continuously.

Abstract: Based on plastic-damage constitutive model of concrete, the developing process of damage domains is simulated for the earthquake analysis of concrete dam by taking account of the change of strain speed and stiffness degradation effect caused by material damage. The plastic-damage constitutive model is applied and the dam-reservoir dynamic interaction resulting from the transverse component of ground motion is modeled using the developed and generalized Westergaard formula added mass technique. Numerical simulation results show that the damaged domains mainly distribute at the change in geometry of upper part of the dam and vertical construction joints. The damaged domains of dam are same as the maximum tensile stress because the tensile strength of concrete is less its compress strength.

Abstract: Fe₃O₄/C composites were prepared by using Fe and polyacrylonitrile (PAN) as precursors, and then heat-treated at temperatures of 600,700 and 800 °C, respectively. The phase composition of the composites at different temperatures was analyzed by X-ray diffraction, and Fe reacted with O from PAN to form Fe₃O₄, which contributed to the improvement of magnetic loss of the carbon matrix. Electromagnetic and microwave absorption properties of the composites were investigated. The results show that the values of real and imaginary part of permittivity were all increased as the temperature increasing, and also the microwave absorption capability was improved.

Abstract: Production of extracellular polysaccharide by the culture of Mycobacterium phlei were examined, using molasses wastewater to replace glucose as carbon source and energy source in the culture medium. Results showed that the COD concentration in molasses wastewater favorable for the growth of the Mycobacterium phlei cell was 5000 mg•L-1, and inoculum size of 5%(v/v), 28°C, initial pH 7.0 and shaking speed of 150 r•min-1, under the optimal culture conditions, the highest flocculating activity achieved for Kaolin suspension was 95.5% and 5.0 g cell/L broth was obtained. The Mycobacterium phlei cell was effective in flocculating some soluble reactive dye in aqueous solution, reactive Light-Yellow K-4G with a decolorization efficiency of 93.5%, respectively, using 20 mL of the flocculant in 500 mL of 100 mg•L-1 dye solution.

Abstract: To improve the performance of traditional hydrogels, dually responsive multi-network hydrogel was designed and fabricated in two steps. Firstly, temperature-and pH-responsive copolymeric microgel of N-isopropylacrylamide, methacrylic acid and polyethyleneglycol methacrylate were prepared via precipitation polymerization in poly (vinyl alcohol) (PVA) aqueous solution. Then glutaraldehyde was added to the microgel dispersion to build crosslinks among microgels and PVA, producing multi-network hydrogel with thermo-and pH-sensitivity. The morphology of the microgel and hydrogel was characterized by electron microscope technique. Swelling and deswelling behaviors show that the obtained hydrogels exhibit good temperature-and pH-sensitivity. The hydrogel shows rapid deswelling kinetics and approaches deswelling equilibrium in ~30min.

Abstract: The expressions of the effective elastic constants of composite material with cylindrical inclusions are derived based on M-T method, and it can be used in discussing the approximate range of effective elastic constant of air. Moreover, it is possible to homogenize tube-sheet by making use of the expression. The numerical result obtained is in good agreement with effective elastic constant adopted by the ASME code. It demonstrates that the approach is effective and accurate. At the last, the relationship between effective elastic and thickness of the tube-sheet is discussed.

Abstract: In this paper, the solid-state reactions between EuCl₃ and pyridine dicarboxylic acid (DPA) are studied. The complex is synthesized by one step solid state reaction at room temperature and the material was characterized by element analysis, fourier transform infrared (FTIR) spectra, absorption and fluorescence spectra. The compositions of complex has been confirmed to be [Eu (DPA)₂(Cl)₂]•6H₂O. Organic light emitting diodes based on the structure of ITO/PEDOT:PSS/PVK:PSS/PVK:Eu/Bphen (12 nm)/LiF(1 nm)/Al were fabricated, the electroluminescence of Eu³⁺ complex was investigated under different driving voltage.

Abstract: Based on the mechanical behaviors of deep soft rock at the accelerating creep stage, a nonlinear rheological cell containing exponential equation replaces classic linear cell, a new nonlinear viscoelasto-plastic creep model of deep soft rock is established on the basis of Nishihara model, and the model can describe the three stages of rock nonlinear creep. Using the least squares method of Matlab to investigate test results, the result shows the new nonlinear creep model accords better with the creep test curves, and verify correctness of the new model.