Applied Mechanics and Materials Vols. 316-317

Abstract: CO2 laser rapidly patterning microfluidic chips on polymer substrate with direct writing ablation had attracted many experts from domestic and foreign in resent years. This method had features of flexible, rapid, easily controllable and high efficient, and was regarded as the most potentialized fabrication method to improve the development of microfluidic systems. This paper systematically reviewed polymer substrate materials, the mechanism of laser and material, fabrication models and factors influenced the fabrication process, as well as the influence on microfluidic chips fabrication quality by laser process parameters. Moreover, the existent problems and possible resolutions based on the mechanisms of interactions between laser and materials was analyzed.

Abstract: The graphite oxide was synthesized with Hummers liquid-phase oxidation method in experiment, and then was reduced to graphene by sodium borohydride, the iron oxide was loaded by dipping method. The catalyst that made reacted in SCR reaction unit in laboratory, the catalysis properties of catalyst was investigated. The experiment results showed that graphene was flake nanometer sheet and presented transparent fold shape, its crystal structure was in order arrangement; the nature of graphene was close to that of raw graphite; their surface function groups were similar; Fe/graphene SCR catalysts had certain catalytic ability in the reaction, the NO conversion rate of catalyst was about 50% while the temperature range was from 200°C to 300°C.

Abstract: Cr-substituted mesoporous aluminophosphate molecular sieve (Cr-MAP) was synthesized and characterized. Crystallization kinetics curves measured as an index to the relative degree of crystallinity, according to the Arrhenius equation to calculate the apparent nucleation activation energy and crystal growth activation energy of Cr-MAP, which was 63.7 and 14.7 kJ• mol^-1, respectively. Cr-MAP had highly catalytic activity for fabricating acetophenone by selectively oxizing ethylbenzene. Using tert-butylhydroperoxide as oxidant and chlorobenzene as solvent at 100 °C for 8 h, acetophenone selectivity, acetophenone yield and ethylbenzene conversion reaches 85.4, 62.2 and 72.8 %, respectively.

Abstract: The anodes of IrxSi1-xO2/Ti (x= 0.2~1) were prepared by thermal decomposition of non-aqueous solution of iridium chloride (IrCl3) and tetraethoxysilane (TEOS). The microstructure and surface morphology of the IrxSi1-xO2 coatings were characterized by XRD and SEM. A large amount of fine crystallites aggregated on the surface of coatings to form a porous structure with a range of particle size of 15-18nm. The particle size decreased firstly and then increased with increase of silica content and received a minimum value at the Ir0.6Si0.4O2 coatings. The electrochemical characterization determined by cyclic voltammetry (CV) indicated that the IrxSi1-xO2 coating with x=0.6 showed a maximum surface charge (q). The experiments of electrochemical synthesis of N2O5 from N2O4 in nitric acid indicated that the Ir0.6Si0.4O2 coating had the best electrocatalytic performance.

Abstract: This paper use the copper content of copper-rich solution is 49.43g/L for electrolyte, and it effecting factors of the quality of electric copper electrodeposition are studied. The results show that under the these conditions of the electrodeposition current density is 180A/m², and time of electrodeposition is 1.5h, concentration of NH₄⁺ in electrolyte is less than 2g/L, thiourea is 40 g/t and Henkel glue is 40 g/t, the cathode copper which have less impurity content and Cu+Ag≥99.95% could be obtained.

Abstract: Poly(vinylidene fluoride) (PVDF) powder was treated with aqueous sodium hydroxide to obtain partially defluorinated fluoropolymers with expected properties such as improved hydrophilicity and fouling resistance (used as membrane material). The effects of concentration of aqueous sodium hydroxide were investigated. The results showed that the membrane’s hydrophilicity increased with increase of the fraction of alkaline treated PVDF powder. The fouling potential also decreased with the increase of the fraction of alkaline treated PVDF powder.

Abstract: The corrosion behavior of 316L stainless steel and alloy 625 were deteced in superciritical water oxidation (SCWO) process for coking wastewater treatment. The operation conditions were 500 °C, 25 MPa, oxygen ratio of 3.5 and the reaction time of 150 h. Surface morphologies of metal samples, oxide structure and compositions across the oxide thickness of the metal samples after SCWO were analyzed using SEM and ESD, and the corrosion rates for both samples were obtained. Pitting corrosion was found on the surface of 316L stainless steel with a corrosion rate of 0.334 mm/a. While no remarkable corrosion was found on the surface of alloy 625, and the corrosion rate is 0.052 mm/a.

Abstract: Nd³⁺ has been immobilized on TiO₂/HNTs with conducting polymers by ions imprinting technology. The results showed that the neodymium ion imprinting photocatalysts could improve the photocatalytic activity of degradation on the tetracycline solution. The photodegradation rate of 40mg L-1 tetracycline simulated wastewater could reach 68.70%.

Abstract: In this study, SbCl₃ as catalyst to benzaldehyde, ethyl acetoacetate and urea as raw material in the ultrasonic radiation synthesis of 3,4-Dihydropyrimidin-2(1H)-ketone. According to the orthogonal design optimization experiment, optimization method ultrasonic extraction technology, and ultimate pass to get the best synthetic condition for: material ratio 1.0,1.0,1.5(mol), ultrasonic power 100 w, ultrasonic time 2 hours, ultrasonic temperature 65°C, the yield is 61.08%.

Abstract: As a nonuniform and unisotropic material with a relatively low tensile strength in spite of high compression strength, a concrete material is vulnerable to bending and tension. Due to the mechanical properties of the current reinforced concrete structures, it is hard for concrete materials to avoid the damages caused by cracks. Although cracks are the easiest things to detect and the most effectively repairable things due to their characteristics, it is very hard to measure them efficiently. In this research, the author measured cracks by visualizing them through mechano- luminescence(ML) paint. By applying ML paint on the surface of the specimen and using the 3-point bending test, the author conducted a quantitative evaluation on the mechanical properties of cracks such as the cracking aspect and length of reinforced concrete. Through the results of this research, the author confirmed the crack propagation speed by section and the mechanical correlation such as between loads and cracks and between deflection and cracks, which means this research was quite successful in analyzing the characteristics of cracks.