Advanced Materials Research Vols. 926-930

Abstract: Crack-free monolithic mesoporous carbon with worm-like structure has been synthesized by low-temperature autoclaving that use triblock copolymer F127 or P123 as composite template, and resorcinol-formaldehyde resol as carbon precursor. The effects of the composite template ratio on the structure of mesoporous carbon were studied by transmission electron microscopy, nitrogen adsorption measurements and element analysis. The results indicated that mesoporous carbon are worm-like structure when use F127/P123 as composite template. Compared mesoporous carbon synthesized by a single template, the pore size distribution of the mesoporous carbon synthesized by the composite template are directly affected by the molar ratio of P123 in the composite templates, however, the pore size is significantly enlarged when using F127/P123 as template. The pore size of mesoporous carbon increased to 12.0nm when the molar ratio of P123 in the composite templates is 67%. We achieved adjustable pore diameter by use F127/P123 changing the molar ratio of P123 in the composite templates.

Abstract: The two-stage deformation was processed to ZM21alloy as cast at different parameter condition, and structure evolution and mechanical property was analyzed. The results indicate that the grain of ZM21 alloy as cast will be fined by the two-stage extrusion deformation, and its size can decreases from about 100μm to 15.6μm. The strength of ZM21 alloy can be raised by the two-stage deformation, up to 261.7MPa, At the same time, the prolongation rate is more than 16% by the two-stage deformation.

Abstract: In this study, Ultrafine WC-VC-NbC-Co was sintered by vacuum sintering at the different sintering temperature. The microstructure and mechanical properties of alloy were analysed by Zeiss optical microscope, SEM-EDS. The results demonstrated that with the increasing sintering temperature, porosity first decreases and then increases, WC grain size enlarges content of η phase decreases. In addition, results reveal the best overall performance was abstained at 1440°C: Density, Vikers hardness, bening were: 14.30g/cm³, 1950HV₃₀, 1787Mpa.

Abstract: The primary purpose of this paper is to study the effects of temperature on crack propagation of nanocrystalline nickel by Molecular Dynamics (MD) simulations. Cracks are loaded in tension mode I. Results show that dislocation emission from a crack tip in nanocrystalline nickel due to the recombination of atomic lattice, then distortion of the crack tip promote crack propagation. The studies we have performed showed that temperature takes a great influence on the crack propagation and the crack shape, and we also found that the crack blunt obviously at high temperature.

Abstract: A pre-cleaning and an electroless nickel plating (EN-HP) were applied to copper foil to improve its tribological behaviour and corrosion resistance. The coating porosity was measured by the corrodkote, tribological behaviour was measured with microhardness tester and a CSM ball-on-disk tribometer, corrosion resistance was measured by potentiodynamic polarization in 3.5 wt.% NaCl solution. Matte nickel plating (mNi) and moderate compact Ni–P coating (EN-MP) were made as comparisons to EN-HP in those tests. By deposition of EN-HP, both coating porosity and tribological behaviour are greatly improved compared to mNi, and the corrosion resistance is distinctly ameliorated to the comparisons. Above research demonstrates that the copper foil with EN-HP coating is good underlay in assemblage of machine.

Abstract: Containing Pb (1.09% ) and Zn (1.97%),the lead-zinc sulphide ore of Bainiuchang mine is a refractory resource in Yunnan Mengzi. The flotation performance of lead is ineffective in plant practice. This research is carried out to enhance the rough flotation performance of lead. With the dosage of lime and zinc sulfate as depressors, sodium hexametaphosphate as dispersant, and ethyl thio carbamate and MA as combined collector, the grinding fineness of 85% , a lead concentrate with lead grade of 17.68%, lead recovery rate of 75.59%, and zinc grade of 7.16% was obtained. The performance of rough flotation of lead is improved.

Abstract: Offshore high-porosity and high-permeability reservoirs, characterized by large pore throat, wide distribution of pore size and enriched sensitive minerals, are easily damaged due to improper use of drilling fluids and completion fluids during the development stage. A series of experimental studies were carried out on the sensitivity damage analysis including X-ray diffraction, scanning electron microscopy, mercury injection porosimetry and core flow experiment. According to the laboratory evaluation results, the reservoir SZLF of high-porosity and high-permeability existed strong water sensitivity and mid to strong stress sensitivity. Furthermore, shielding and temporary plugging technique applied for reservoir protection was put forward, and laboratory tests showed that it had a better effect on solid intrusion prevention.

Abstract: In order to provide evidence for the adjust of grinding rate, we have did the experimental study on the grinding rate with different grinding concentration of Dahongshan copper, the tests indicate that the best grinding concentration and grinding rate of Dahongshan copper is 70% and 100%.

Abstract: Based on the determination of the equilibrium surface tension for anionic surfactant SDS and non-ionic surfactant TrionX-100 under different concentrations, the two surfactants continuous boiling test and the SDS for the hydrolysis tests were carried out. Objective is to analyze the diminishing process for active ingredient of the surfactants. Results show that the liquid with surfactant is capable of reducing the surface tension. With the increment of surfactant concentration, the surface tension decreases gradually, and the surface tension is minimized under the critical micelle concentration (CMC); When the concentration lower than CMC, the surface-active of TritonX-100 presented is stronger than the SDS. At continuous boiling experiment, the thermal stability of TritonX-100 solution is better than the SDS. When the SDS aqueous solution is in the sealed environment with set temperature and the continuous boiling environment under experiment situation, the active ingredients of SDS solution will change and the equilibrium surface tension will be undermined. Owing to the chemical losses, the inherent characteristics of solution perform dramatically different from the original one during boiling experiment, which includes the hydrolytic destruction and micro-layer pyrolysis chemical effects.

Abstract: In order to save water and reduce the cost of water on campus, the bath wastewater recycling by membrane bioreactor is studied. The results show that the treatment of bath wastewater by membrane bioreactor has good effect with COD＜50 mg/L and its average removal is 82.55%, NH₃-N＜10 mg/L and its average removal is 72.17%, turbidity＜0.5 ntu, average value of chromaticity is 26.43 tu and it is tasteless. The treated water of membrane conforms to the urban miscellaneous water standard (GB/T 18920-2002) and the processing cost is 1.45 yuan/m³ which is below the tap water price, and the economic benefit is obvious.