Advanced Materials Research Vols. 912-914

Abstract: Hierarchical calcium carbonate spheres composed of nanoparticles has been successfully synthesized via a solvothermal process. The structures are fabricated by the reaction of Ca (CH₃COO)₂ with (CO(NH₂)₂) at 110 °C in diethylene glycolwater mixed solvents in the presence of polyvinylpyrrolidone. The as-prepared products were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The characterization results revealed that the average diameter of the hierarchical calcium carbonate spheres is about 5 μm, and the size of the nanoparticals range from 50 to 100 nm. In addition, a small amount of bundle-like aragonite calcium carbonate is also obtained in the experimental parameters.

Abstract: To establish the determination of the content of chlorhexiidine acetate by ultraviolet spectrophotometry .The spectra (range: λ=200~320 nm) were processed. The linear ranges of chlorhexidine acetate was at 2~ 20 μg mL^-1 .the chlorhexiidine acetate showed good linear correlation.The ultraviolet spectrophotometry data of the samples were also used to evaluate the samples quantitative composition.It was shown that recovery of the method by standard addition method was respectively valued 99.55% for chlorhexiidine acetate .The method was simple,reliable,accurate,reproducible with high sensitivity and selectivity.

Abstract: VO₂ films were grown on sapphire substrates by pulsed laser deposition (PLD), and the structural and optical properties of as-grown films were investigated by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), photoluminescence (PL), and optical-transmission measurements. The oxygen partial pressure in the growth chamber was found to be the key factor deciding the microstructure and properties of as-deposited VO₂ films, and its effects and corresponding mechanism were investigated systemically. Results indicated that dense and uniform VO₂ films with smooth surface were achieved by PLD under optimized oxygen partial pressure. Strong blue emission peaks were observed in room temperature photoluminescence (PL) spectra. Excellent selective optical-transmission of the VO₂ thin films from 200~3000 nm were also recorded at room temperature.

Abstract: s: Rigid Pavement composite performance is more complex, there is no analytical formulas can better predict its mechanical properties. This article by buried sensors in ShanMei Expressway Cement Asphalt Paving Project, on-site monitoring of the actual variation of the mechanical properties of the composite pavement structure, this study provides a theory basis for the optimization design of highway asphalt overlay structure of Cement Concrete Pavement.

Abstract: In this paper, the variation of viscosity with time is studied under condition of different influencing factors such as shearing time, mass concentration, salinity and temperature. The applicable conditions are optimized as following: The optimum mass concentration, salinity and temperature through laboratory experiment is 3000 mg/L~4000 mg/L, 40000 mg/L~80000 mg/L with Ca²⁺ under 5000 mg/L and 20 °C~60 °C respectively. Finally, anti-shearing and oil displacement experiment are carried out under laboratory conditions. The results show that the new polymer after being sheared also has the ability to self-assemble and the enhancement in oil recovery obtained in core flow experiment is higher than conventional polymer flooding, which suggests that it has a wide application prospects in tertiary oil recovery.

Abstract: Electrochemical corrosion behavior of epoxy aluminum coating immersed in 3.5%NaCl solution was investigated using electrochemical impedance spectroscopy (EIS). SEM was also used to analyze the surface images of coating, and the failure mechanism was discussed as well. The experimental results showed that corrosive species can penetrate into coatings and reach the coating/substrate interface promptly, causing the decrease of electro-resistance and the beginning of electrochemical corrosion at the coatings/metal interface. The coating was compact and continuous at beginning, while the blisters and cavities appeared after corrosion, which were formed osmotic pressure created by corrosion species penetration.

Abstract: Currently, the Oxygen-enriched combustion technology of boiler is gradually developing and its application dimensions and area are continuously expanding. The paper discussed the background and significance of oxygen-enriched technology, and described its theatrical basis. Introducing the developing course and instance of membrane method for oxygen making and oxygen-enriched combustion technology, the paper prospecting the technology, pointed out that oxygen-enriched combustion technology would has wide foreground at energy saving and environment protection.

Abstract: A novel gadolinium diethylenetriamine-N, N-bis (2-acetamide benzoic acid)-N, N-bisacetic acid complex has been synthesized and characterized by elemental analysis, infrared spectrum, ultraviolet spectroscopy and thermal analysis. The interaction between Gd³⁺ and aminopolycarboxlicacid ligand was investigated by fluorescence titration. The binding constant of this complex is calculated to be 1.2018×10⁴ L·mol^-1, and binding stoichiometry is 1:1. Fluorescence spectra was also used to study the interaction between Gd (III) complex and bovine serum album (BSA). The results showed that Gd (III) complex can effectively quench the intrinsic fluorescence of BSA via static quenching. According to Stern-Volmer equation and Linewerver-Burk equation, the binding constant is calculated to be 3.7491×10⁴ L·mol^-1 and binding site is about 1.0.

Abstract: In this study, shell powder was modified by sodium stearate surface modifier for improving the compatibility of SP with polymer materials. The surface modifiers influence on the physical and chemical properties of SP were studied by scanning electron microscope (SEM), fourier infrared spectrum (FT-IR), surface contact angle meter, XRD diffraction analysis meter and other modern instruments and analysis method. The results showed that the surface modifier was successfully coupled to the shell powder surface. After surface modifier modification, the interfacial compatibility of the shell powder with polymer materials was effectively improved. The contact angle of shell powder surface increased from 73.5 ° to 110.8 ° , along with the dosage of sodium stearate surface modifier was 4.0%. All results suggested that modified shell powder is promising for using as a reinforcement filler in polymer materials.

Abstract: Li₃V₂(PO₄)₃/C composites were synthesized by sol-gel routine with citric acid as chelates and carbon sources at different preparation conditions , meanwhile saccharose has been used to separate the Li₃V₂(PO₄)₃/C particles When it dissolve out in the process of solvent volatilizing. The effects of different preparation conditions and the existence of saccharose on crystal structure and electrochemical performance were characterized by XRD, SEM and electrochemical workstation. The results shows that all the Li₃ V₂ (PO₄)₃ samples are pure monoclinic phase; The crystal structure and the lattice parameters remain unchanged in different conditions, but it has effects on their average size of particles. The existence of saccharose suppress the growth of particle size and particle aggregation, and then affect electrochemical performances indirectly. In addition , the cycling performances of all samples displayed well at 3.0~4.2V on low rate charge/discharge, but the rate performance become worse with the increasing of average size of particle and particle aggregation and the capacity reduces seriously on high rate charge/discharge.