Applied Mechanics and Materials Vols. 130-134

Abstract: AuNi alloy was synthesized by vacuum arc melting in high-purity argon atmosphere. The AuNi alloy was characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results of EDS indicated that Au and Ni atoms were well-distributed in the alloy. Moreover, the results of XPS exhibited an electronic transfer from Ni to Au in AuNi phase. The Electrocatalytic oxygen reduction reaction (ORR) activity and the methanol tolerance of the AuNi alloy were respectively investigated using the RDE method and the electrochemical cyclic voltammetry. The results suggested that O₂ was directly oxidized to H₂O on the AuNi catalyst via an approximate four-electron reduction pathway, and that the AuNi catalyst had a high electrocatalytic activity for the ORR and an acceptable methanol tolerance, simultaneously.

Abstract: In this work, high compression strength silicon hybrid material was prepared through a sol-gel process. Structure of high compression strength hybrid material was characterized through FTIR spectra. The molar ratios of MTES to TEOS, mass ratio of siloxane to modified silicate sand were optimized to enhance compression strength. The results showed that linear Si-O-Si network and fourfold siloxane rings were produced in the sol-gel process which were necessary to obtain high compression strength material. When the volume ratio of MTES to TEOS was 3.0 and mass ratio of siloxane to sand was in the range of 0.64~0.70, the hybrid material showed high compression strength of 5.49 MPa.

Abstract: Mesoporous TiO₂ films was prepared by evaporation-induced self-assembly and dip-coating method. And the pore size of the TiO₂ films is adjusted by controlling the molar ratio of H₂O/TiO₂ (H value). Water contact angle was chosen to represent the hydrophilic property, and XRD and AFM were carried out to characterize the films. With the increase of H value, the pore size increased firstly then decreased. And when H is 15, the pore size is the biggest, which hydrophilicity in dark is the best too. With the extention of the non-irridation time, the hydrophilicity is worse. And the reason may be ascribed to the adsorption of organic matter in air.

Abstract: The fire fighting equipments used for fight forest and grassland fire of China are mainly small two-stroke gasoline-powered portable wind fire-extinguishers owing to these areas are located in the more remote and inaccessible, where generally stay away from water. The main drawback of the wind fire-extinguisher is that it would lower the efficiency of power attributed to overheating of the two-stroke gasoline engine in the long process of firefighting, which will lead to decline the output speed and volumetric flow of fire extinguishing wind drived by the turbine when fire ambient temperature is high in the spring and summer. If this situation occurs, it will reduce efficiency of its fire fighting, what is more the adverse effects of wind to help the fire rather than put out the fire because the output of the extinguishing wind speed and volumetric flow is too small. In order to avoid the occurrence of such adverse effects and improve the extinguishing effect of fire extinguishers in the long process of firefighting, a program which use CO₂ coordinate with wind fire-extinguisher to put out a fire was proposed in this paper, and the structure, characteristics of operation and precautions of the CO₂ fire-extinguisher were described detailly.

Abstract: Perovskite-type cathode materials La_0.6Sr_0.2Ca_0.2Co_1-yFe_yO_3-δ (0.2≤y≤0.5, marked as LSCCF62282, LSCCF62273, LSCCF62264 and LSCCF62255) for intermediate-temperature solid oxide fuel cells (IT-SOFCs) were prepared by solid state reaction. The establishment process and phase transformation were measured by TG-DTA, FT/IR and XRD techniques. Single hexagonal perovskite phase can be achieved after sintered at 1100 °C for 3 h. Mixed conductivity, thermal expansion behavior and chemical stability of sintered samples at 1100 °C for 3 h have been investigated. At intermediate temperature (600-800 °C), the mixed conductivity characterized by DC four-probe technique is higher than 100 S/cm. LSCCF62282 has the highest conductivity of 297.3 S/cm at 700 °C among the four samples. At lower temperatures, the conductivity follows small polaron hopping mechanism. Thermal expansion coefficients (TECs) of the samples from 50 °C to 850 °C exhibit a reducing tendency with increasing amount of doped Fe³⁺. Thermal expansion behavior can be improved by doping with Ca²⁺ and Fe³⁺ commonly. XRD pattern for LSCCF62282 and YSZ mixture sintered at 800 °C for 6h indicates that cathode material LSCCF62282 is chemically stable against YSZ electrolyte at operating temperature.

Abstract: The fatigue property of welded specimen of different form of Ti6Al4V Titanium Alloy plate was researched in the environmental condition of atmosphere and salt fog,The test results indicate the holes along weld seam in welding specimen have great influence on fatigue property, The fatigue life of Ti6Al4V Titanium Alloy doesn’t low under the salt fog condition in high stress range. The salt fog brings about the influence on fatigue life obviously at the same corrosion condition with fatigue stress lowering.

Abstract: Thiophene is a typical thiophenenic sulfur compound that exists in coking benzene. In this paper, investigate oxidation chlorination of thiophene in coking benzene. Potassium permanganate was combined with hydrochloric acid for a new KMnO₄/HCl system of oxidation desulfurization. The preliminary results show that the thiophene in the benzene cannot be deep oxidized desulfurization alone potassium permanganate solution even at acetum. The thiophene in the coking benzene could be mostly converted by using KMnO₄/HCl system. In suitable reaction conditions thiophene’s removal rate can reach more than 93%.

Abstract: Metal Rubber is a kind of material with nonlinear of resuming force. In the dynamic test of Metal Rubber based on the control of displacement loading, its force-displacement curve is a hysteretic loop. The hysteretic phenomenon is studied with the means theory and experiment in this paper. The generalized restoring force is the binary function of displacement and speed. For the binary function, it is unilateral to represent the hysteretic loop only on the displacement-force plane, so the space hysteretic loop is introduced. The important parameters of the linear vibration isolators are stiffness and damping coefficient, however the nonlinear vibration isolators have stiffness and damping function, which all need be identified from the tested data. The results have proved that the dynamic model can meet the requirements of dynamic analysis of Metal Rubber in engineering.

Abstract: The scaled swine farms have been developed rapidly in China since 21^st century, which bring serious problem in environmental pollution, especially in winter. In order to s reduce the pollution from intensive scaled swine farms, as well as produce biogas in winter, a technological route was put forward to control the sewage pollution in swine farm by using bio-tank of glass fiber reinforced plastics (GFRP). The experiments in swine farm of FuJian Hua Feng Co. Ltd in Nanping city showed that the developed technology had achieved zero-draining, which was able to solve the pollution problem and produce biogas in winter. The sewage temperature of bio-tank of GFRP increased average 1.18°C more than that of bio-tank of reinforced concrete. And the average biogas-generating rate of bio-tank of GFRP of year 2009 was 0.45 m³·m^-3·d^-1, which increased 28% more than that of reinforced concrete. The indexes of COD, BOD, SS, NH₃-N, and TP for the out-let wastewater of the treatment were 579.1 mg·L^-1, 237.7 mg·L^-1, 289.8 mg·L^-1, 319.4 mg·L^-1and 31.7 mg·L^-1, respectively.

Abstract: This paper proposes a new packing algorithm for strips cutting method in steel plate cutting technology. It remarks the shapes by many horizontal lines. It firstly searches the best sequence and each shape’s angle for packing all shapes by genetic simulated annealing algorithm, and then a new heuristic algorithm which satisfies the practical need of strips cutting technology based on the bottom-left algorithm is used to complete the automatic layout of two dimensional irregular shapes. In the end, satisfactory results of optimal layout are obtained.