Applied Mechanics and Materials Vol. 618

Abstract: A study on vacuum diffusion bonding between as-extruded AZ31 magnesium alloy and 7075 aluminum alloy was carried out according to atomic diffusion theory. Recrystallization annealing was used for grain refinement of AZ31 magnesium alloy and 7075 aluminum alloy before the diffusion welding. The quality of the bonding joints was checked by shear test, micro-hardness test and microstructure analysis. Experimental results showed that the welding temperature and holding time have a great effect on the joint shear strength. The maximum of shear strength was 38.41MPa under the temperature of 470°C and the holding time of 60min. The result of micro-hardness measurement showed that the micro-hardness of welded joints was maximum. Three kinds of intermetallic compounds, Mg₂A1₃, MgAl and Mg_l7Al₁₂, formed at the interfacial transition zone at 470°C.

Abstract: We used surface treatment technology to handle wasted polyurethane foam in this paper. And made out a series of new oil absorbed foams to realize the waste reused. We used the following two technical schemes to improve oil absorption of the polyurethane foam: 1 Dealing polyurethane foam with tung oil;2 Dealing polyurethane foam with tung oil and organic silicon compoundly. Study shows the oil absorbency is up to 22.4 times when using tung oil, at the same time when the concentration of organic silicon is 1:5 , the oil absorbency is 16 times. The oil absorption effect of polyurethane soft foam which experiences the twenty-minute tung oil processing is the best.

Abstract: Fluid drag is an important phenomenon at solid-liquid interface. In nano/microfluidics, it has significant importance due to small surface to volume ratio. Slip at the interface is an important phenomenon which reduces the friction at the interface. In this study we have proposed a more general theoretical model for the slip induced magneto-hydrodynamic (MHD) flow across parallel plates. We have analyzed the effect of slip parameter on the velocity and the flow rate across parallel plates. The effect of magnetic field on velocity and the flow rate has also been discussed. Our results show satisfactory agreement with the previously conducted experimental and analytical studies. In this paper, we have briefly discussed and compared the new model with the existing experimental and theoretical studies.

Abstract: The study combines the UV/TiO₂ and an ultrasonic procedure to degrade the azo dye wastewater of Acid Yellow 17 and investigates the effects of various factors including the quantities of TiO₂ and iron ions added on the efficiency of the removal of the azo dye wastewater of Acid Yellow 17. The experimental results reveal the a significant additive effects occurs through the combination of the two procedures under the 13 watts UV irradiations and 10 watts ultrasound. The analysis of the catalyst properties indicates that there are no evident changes of the appearance of the crystal and TiO₂ catalyst when UV/TiO₂ is combined with ultrasonic procedures. Since the formation of hydrogen peroxide (ND≦1 mg L^-1) was not detected during the reactions, the additions of Fe (II) and Fe (III) are unable to induce the Fenton-like reaction effectively. Nevertheless, the additions of Fe ions significantly affect the degradation rate of the dye. Moreover, the effect of Fe (III) was found to be superior to that of Fe (II) under the same concentration.

Abstract: A new coumarin-1,2,3-triazole diad was designed and synthesized by Pechmann-Duisberg reaction and click chemistry. The three-step synthetic route to the target compound afforded an overall yield of 56%. The structures of the synthesized compounds were characterized by ¹H NMR, ¹³C NMR, IR and mass spectrum. The click chemistry provided an ideal approach for synthesis under mild conditions of coumarin-1,2,3-triazole diads which may exhibit excellent biological activities such as antitubercular activity.

Abstract: The three-dimensionally ordered nanopores 3DON lithium ionic sieve precursors Li₄Ti₅O₁₂ were synthesized by homemade polymethyl methacrylate (PMMA) colloidal crystal templates filled with lithium acetate, tetrabutyl titanate, oxalic acid and critric acid mixed solution after melt crystallization. The corresponding LiTi-H as a new lithium ion-sieve was obtained after the dilute hydrochloric acid treatment. The morphology and structure of the material were analyzed with SEM and X-ray diffraction (XRD), and saturated exchange capacity, adsorptive selectivity and reusability characterized the ion exchange properties. It turns out that PMMA colloidal crystal templates and 3DON precursors Li₄Ti₅O₁₂ arranged orderly and macro pore diameter was approximately 80nm. What’s more, Li₄Ti₅O₁₂ were spinel phase and lithium ionic sieve LiTi-H had a high selectivity for Li⁺, saturated exchange capacity for Li, 56.81mg (Li⁺).g^-1 and good acid stability.

Abstract: Polyaspartic acid (PASP) and a copolymer (AA) of acrylic acid and acrylicester were synthesized. A ternary composite (PASP-AA-DTPMP) was made from PASP, AA and DTPMP. The performances of ternary composite were studied by using static scale inhibition and weight loss of rotating hung steel slices test. When the concentration of ternary composite was 6mg/L, the scale inhibition rate reached 95% and the corrosion inhibition rate reached 97.9%. The results showed that the ternary composite had good scale and corrosion inhibiton performance and was suitable for high temperature and hardness circulating cooling water system.

Abstract: Cyclic carbonate emulsion was prepared by means of polymerization technology using DOMA (which was synthesized by glycidyl methacrylate and carbon dioxide) and acrylic monomers. Effect of temperature, amount of emulsifier, initiator, DOMA and acrylic acid on properties of the emulsion and the film were studied. It was found that with 4% emulsifier, of which the ratio of OP-10 and SDS was 2:1, and 0.4% initiator, 3.5% acrylic acid, 13.3% DOMA, the temperature was 78°C. Under this condition the performance was the best, and then the aqueous non-isocyanate polyurethane was synthesized by cyclic carbonate emulsion and diethylenetriamine as curing agent. The structure of emulsion and aqueous non-isocyanate polyurethane was characterized by FTIR.

Abstract: Work is devoted to the study of new catalysts on the basis of polymermetalyc complexes of transition metals in the oxidation of toluene. Catalytic agents on the basis of iron (III) complexes with the copolymer polietilenimin-polyacrylic acid put on a silicate substrate have been investigated. Special attention is paid to study influence of physical and chemical parameters on oxidation process, to fixing of kinetic and thermodynamic indexes of process.

Abstract: The Manganese^II Isovanillin complex [Mn₂(C₈H₇O₃)₄(H₂O)₂], Diaqua-tetra (isovanillinato-O,O')-bis (manganese^II),the Mn^II atom is coordinated by three isovanillinate anions and one water molecule in a distorted trigonal bipyramidal configuration with five-coordinations geometry. And one isovanillinate ligand chelates to the Mn^II atom through its methyl and hydroxy O atoms, the other two isovanillinate ligand chelates to the Mn^II atom only through its hydroxy O atoms. The same as another Mn^II atom. So we get a Binuclear Mn^II metal complexe. The fact clearly suggests not so much significant contribution from the electrostatic interaction in the Mn-O bonding in Binuclear Mn^II metal complexes as we gotten in mononuclear Mn^II metal complexes. Adjacent complex link to each other via hydrogen bonds forming the three-dimensional supramolecular structure.