Applied Mechanics and Materials Vols. 401-403

Abstract: The iron oxide/graphene (Fe₃O₄/rGO) nanocomposite modified electrode and the electrochemical properties of Sudan I were investigated. It was found the anodic peak current of Sudan I was linear with the concentration of Sudan I from 0.008 μM to 6 μM with a detection limit of 0.0005 μM (S/N=3). The regression equation was: I_pa (μA)=-0.8151-0.9651c (μM), R=0.9934. It was convenient and excellent sensitive electrochemical method for Sudan I determination. This electrochemical method was successfully applied to determine Sudan I in food samples.

Abstract: In this paper, the oxygen evolution potential and kinetics of Pb–0.3%Ag-0.06%Ca rolled alloy anode during the 15 days electrolysis in acid zinc sulphate electrolyte solution were investigated with galvanostatic polarization curve and Quasi-stationary polarization (Tafel) techniques. The results revealed that the anodic oxygen evolution potential and reaction kinetics varied a lot during the electrolysis for it is a process indicating the formation and stabilization of anodic oxide layer. With the increasing electrolysis time, the potentials (MSE) and overpotentials of oxygen evolution mainly present a declining trend while the electrode surface exchange current density a rising trend.

Abstract: Determination of the surface integrity is of particular importance because of its influence on workpiece service life. The microstructure of 7050-T7451 aluminum alloy under the cutting speed of 3000~5000m/min was observed in this paper. With the increase of cutting speed, microhardness was analyzed to investigate the thermal softening phenomenon engendered, which would affect the surface performance in return. According to the results, influences of cutting speed on microstruceture and microhardness in high speed were explored and further research on temperature in high speed is suggested.

Abstract: Ag₃PO₄ photocatalyst was successfully synthesized via a aqueous precipitation process using AgNO₃, NH₃·H₂O and NH₄H₂PO₄ as raw materials, and characterized by X-ray diffraction (XRD),solid-UV-Vis and FE-SEM techniques. Photodegradation of Methylene blue solution,Rhodamine B,was studied with Ag₃PO₄ under experiment light recourse of metal halide lamp . The XRD result showed that the sample Ag₃PO₄ synthesized in a high purity belongs to tetragonal. And the sample has a strong absorption between 200 nm and 400 nm analysized by UV-Vis. The photodegradation experiment showed that Methylene blue solutionRhodamine B was more easily photodegradated with Ag₃PO₄ and light recourse was metal halide lamp.

Abstract: This study investigated the use of nanoscale bilayers assembly for hydrophilic surface modification on stainless steel plate. This study first performed nanoscale bilayers assembly method, with the addition of top layer coatings for durability purposes, to modify the surface structure and thereby the hydrophilicity of the surface at 15, 17, 20, 23, and 25 bilayers. The relationship between the number of bilayers and the resulting contact angle was then empirically established. Results showed 17 bilayers to be the optimal number of bilayers among the samples tested, resulting in the smallest contact angle of 11° (compared to 70° on unmodified surface), corresponding to the highest surface wettability and hydrophilicity. From 0 to 17 bilayers, the contact angle seems to decrease linearly with the number of bilayers. Beyond 17 bilayers, at 20, 23, 25, and 30 bilayers, the samples showed no significant improvements in contact angle or hydrophilicity.

Abstract: Single-phase Ba₅(PO₄)₃Cl:Ce³⁺,Tb³⁺ (BPCl:Ce³⁺,Tb³⁺) samples have been synthesized via solid-state reaction method. The phase structure and luminescence properties are characterized using powder X-ray diffraction (XRD), photoluminescence excitation and emission spectra. Effective energy transfer occurs from Ce³⁺ to Tb³⁺ due to the observed spectral overlap between the emission band of Ce³⁺ and the excitation band of Tb³⁺. Ce³⁺/Tb³⁺-codoped Ba₅(PO₄)₃Cl shows more intense yellowish-green light compared to that of Tb³⁺-doped sample under UV light excitation.

Abstract: nanoAl₂O₃ has been synthesized by homogeneous precipitation method using dodecyl trimethyl ammonium bromide (DTAB) as surfactant. The as-prepared powder was characterized by FT-IR, XRD, TEM and SEM. The results indicate the surfactant existence in the precursors but disappeared in the products. This is mainly due to the combination of precursor and surfactant, which results in particles of nanosize. The nucleation and growth rate during the precipitation has also been controlled by the addition of surfactant. During the calcination process, the surfactant has decomposed and volatilized into air. The XRD characterization shows the calcined powders were γ-Al₂O₃ particles with mean size of 27 nm, which was in accordance with TEM characterization. The morphology of the prepared alumina particles has also been investigated by SEM and showed that the powder has a spherical morphology with a uniform particle size.

Abstract: High boron alloyed stainless steel composite plates with different Ti content by cladding casting and hot forming process were fabricated. The mechanical properties of composite plates were analyzed after solution treatment. The results show that the composite plate has optimal microstructure and properties at 1100°C solution temperature, holding for 4h.The comprehensive properties of the composite plates are improved with the increase of Ti content, but excess Ti content can lower the plasticity. The elongation and the tensile strength of composite plate reaches 29% and 527MPa respectively, the mechanical properties can meet and exceed the supply standard requirements in ASTM A887-89 of U.S. when the reasonable content of Titanium is about 5%.

Abstract: When acoustic wave passes through concrete, it can reflect concrete quality information through velocity of sound, amplitude, and frequency. Because single acoustic parameter is incapable of reflect concrete quality information in full, the paper carry out the research of multi-parameter models of strength estimation of cement concrete. The paper founded multi-parameter mathematic models of strength estimation on based of wave equation with ultrasonic method. These models consist of dual-parameter model I between velocities of sound, attenuation coefficient I and compressive strength , dual-parameter model II between velocities of sound, attenuation coefficient II and compressive strength, and tri-parameter between velocities of sound, attenuation coefficient I, and attenuation coefficient II and compressive strength. Correlation coefficient of strength estimation of dual-parameter and tri-parameter models is higher. When testing distance is equivalent standard test block in detecting structure of cement concrete, these models may be adopted strength estimation of dual-parameter and tri-parameter models apply in Penetrating method of ultrasonic directive wave.

Abstract: This paper studies the performance change by adding a certain percentage of graphene and high-temperature reduction graphene to copper powder,which would be sinteringed by Spark Plasma Sintering (sps) under certain temperature and pressure. The image of electrical conductivity measured by Physical Property Measurement System (ppms) showed that the electrical conductivity of the sample added with graphene increased by 4.39% compared with the sample added with no graphene. Meanwhile ,hardness increased by 50%. It showed that graphene could improve the conductive properties as well as the strength of copper, which suggests the graphene will have great potential application in power transmission conductor and electrical contact materials.