Applied Mechanics and Materials Vols. 66-68

Abstract: Divided flow extrusion deformation behaviors and as-extruded tube properties of AZ31-Ce-Sb alloy were investigated. Addition of Sb and RE in AZ31 could accelerate the nucleation of dynamic recrystallization grains and refine tube microstructure. Compared to AZ31 Mg alloy, higher deformation temperature, extrusion speed and ration were allowed. AZ31-1%Ce-1%Sb alloy tubes had much better comprehensive performance.

Abstract: In the present study, the Zr-Cu-Ni-Al based bulk metallic glasses with different Ti addition was successfully prepared by suction casting . It was found that the glass forming ability was improved with increasing of Ti content from 3 at.% to 7 at.%. However, with increasing of Ti content, the room-temperature plasticity decreased from 4.33% to 0.66 %.

Abstract: The research is aimed at presenting a novel determination method of IPMC (Ionic Polymer Metal Composites) Young’s Modulus. This method would fill up some deficiencies, such as damaging the tested IPMC strip, having low precision and so on, in the traditional method like tensile test and bending test. The paper presents a novel determination method based on cantilever resonance theory. Cantilever resonance theory is one of the methods to determinate the Young’s modulus of metal wire and metal strip. This method adopts Euler-Bernoulli beam to build a vibration differential equation of the beam. Then, by using the separate variable method, the general solution of the equation would be obtained. Considering the boundary conditions, a formula about the relation of the Young’s modulus and the first natural frequency is obtained. Limited by the experimental equipment and test method, this method has not been applied in the composite material. This paper attempts to apply this method in the IPMC material. The laser probing DISP (displacement) technique is applied in the test experiment. The laser displacement transducer is a kind of accurate un-contact laser displacement measurement set. The distance measured, which could be used to measure the change in position of the tested object, is based on the triangle principle.

Abstract: Under the Euler-Bernoulli beam theory, the wave propagation method is used for the vibration analysis of beams with arbitrary boundary conditions. The boundary conditions end the beam could be arbitrary that all the conventional homogeneous beam boundary conditions can be included by setting the stiffnesses of the springs be infinity or zero. In this paper, the flexural displacement of the beam is expressed in the wave propagation form including wave numbers. The wavenumber could be obtained in a known form for conventional boundary conditions. So the results are obtained through the boundary conditions and the known wavenumbers and compared with the numerical results. In order to validate the correctness, results with different stiffness are compared with those obtained by previous published papers.

Abstract: According to problems existed in the current farm machinery scheduling process, a new farm machinery scheduling scheme is adopted in this dissertation. The collaborative scheduling model of farm machinery is established and multitask collaborative scheduling algorithm is designed through analyzing the differences between Vehicle Scheduling Problem and agricultural machinery scheduling in the dissertation. Earliest Start Time First and minimal resource allocated capacity first strategies are used in the farm machinery scheduling. The algorithm is useful for the case of machinery owner with sufficient farm machinery. The experiment proves that the collaborative scheduling algorithm is more effective than the serial scheduling algorithm.

Abstract: A templated carbon has been prepared by using a clinoptilolite-Ca mineral as template and furfuralcohol as carbon source. X-ray diffraction (XRD), nitrogen adsorption, scanning electric microscope (SEM) and cyclic voltammetry (CV) are used to analyze the phase composition, pore structure, micro morphology and electrochemical performance. The specific surface area of the templated carbon is 590m²/g and the mesoporosity is high to 63.4%. In H₂SO₄ medium, due to its rich mesopores, the carbon exhibits a large capacity and a good rate capability. The capacity of the carbon is 174F/g at a scan rate of 5mV/s. When the scan rate increases from 5 to 300mV/s, the capacity of the carbon decreases only from 174 to 144F/g, exhibiting a good rate capability.

Abstract: In this paper, LiMn2O₄ materials were prepared by a solution combustion synthesis method using acetate salts as raw materials and acetic acid as fuel. The effect of further calcination at 500°C and 600°C on the phase structure and composition were investigated. The composition and phase structure are determined by X-ray diffraction (XRD). XRD results indicated that the main phase of the products was LiMn2O₄, and there was a trace amount Mn₂O₃ impurity in the products prepared at 500°C and 600°C. The impurity Mn₂O₃ in the products prepared at 500°C is increased with increasing calcination time, but the Mn₂O₃ in the products prepared at 600°C is decreased. The grain sizes of the products prepared at 500°C and 600°C are increased with increasing calcination time, and the grain sizes of the products prepared at 600°C are larger than these of the products prepared at 500°C. The lattice parameters of the products prepared at 500°C and 600°C are smaller than that of LiMn₂O₄ with perfect crystal, and the lattice parameters of the products are more close to that of LiMn₂O₄ with perfect crystal.

Abstract: Fe doped LiFe_xMn_2-xO₄ materials were prepared by a low-temperature molten-salt combustion synthesis method. The phase structure and compositions of the products were determined by X-ray diffraction (XRD). The investigation on Fe doping content indicated that the main phase of the as-prepared products was LiFe_xMn_2-xO₄, and the impurity was Mn₂O₃. With increasing Fe doping content, the relative content of Mn₂O₃ and the lattice parameter of the products were decreased, and the crystallinity was increased. The study of the calcination temperature on LiFe_0.1Mn_1.9O₄ suggested that the main phase of the LiFe_0.1Mn_1.9O₄ materials prepared at 300-600°C was LiFe_0.1Mn_1.9O₄. Mn₃O₄ and MnO impurities could be investigated in the product prepared at 300°C, and single impurity Mn₂O₃ could be observed in the products prepared at 400-600°C. The relative content of Mn₂O₃ decreased, and the lattice parameters and grain size of the products were increased with increasing calcination temperatures.

Abstract: In this paper the propagation properties of axisymmetric compression wave in an infinite and transversely isotropic magneto-electro-elastic cylinder are investigated. Numerical results show that mechanical boundary conditions have obvious and different influences on the propagation properties of axisymmetric compression wave in a magneto-electro-elastic cylinder.

Abstract: Mobile agent (MA) is an offspring of distributed technology combined with agent technology and it is a intelligent agent with mobility. So it has good application potential in distributed network. The appearance and characteristics of mobile agent are presented, and then three standards and criterion related to the mobile agent are summarized. Five representational mobile agent platform (MAP) are discussed and their communication paradigm and structure, providing service and characteristics are compared. Finally, the application potential, deficiencies of current research and the possible trend of mobile agent technology (MAT) are discussed.