Advanced Materials Research Vols. 476-478

Abstract: (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 (BZN) ceramic samples were prepared by solid state reaction, In order to reduce the sintering temperature of BZN ceramic we have used liquid coating technology to dope CuO by precursor solution of CuSO4. The sintering behavior, microstructures, phase structures, and dielectric properties were studied. The process reduces the amount of sintering aid and minimized the negative impact of sintering aid on dielectric properties. A ceramic composite which could be sintered well at 900°C and showed good dielectric properties of εr=161,tanδ=0.005 and TCF=-398ppm/°C（1MHz）was obtained when 0.5mol/l CuSO4 was added to the (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 ceramic.

Abstract: In this paper, the influences of MnO2 and V2O5 on the varistor properties of ZnO- V2O5-based ceramics were examined. The results show that, the addition of MnO2 to the ZnO-V2O5-based ceramics was found to improve varistor properties. The sintered temperature was benefit to enhancing the growth of crystals of the samples and the non-ohomic coefficient can be improved. The samples have non-ohmic coefficient α=27.8 and varistor voltage U1mA=60.9V/mm when they are sintered at 1100°C with 2 hours.

Abstract: By using ordinary lathe, carried out cutting experimental study with cylindrical turning 45# steel on TiB2 ceramic cutting tool. By using Stereo Microscopy and Scanning Electron Microscopy, recorded cutting tool surface’s friction and wear conditions. The results showed that higher cutting speed could made surface roughness decrease and surface quality better; TiB2 ceramic cutting tool’s wear mechanism was abrasive wear, aoxidation wear; wear of blade tip and main flank face were more serious.

Abstract: A toughening model of crack bridging reinforced ceramic matrix composites is presented. It was shown that this transition closely relates to the extent of toughness, particle size or volume fraction, and the particle yield stress. The constitutive equation is obtained through micromechanical considerations based on crack bridging toughening. The results show that the model is in good agreement with SEM results.

Abstract: Porous α-Fe2O3 nanorods were prepared by the hydrothermal method from FeCl4 and urea without templates. The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) analysis techniques. The as-prepared α-Fe2O3 has the porous nanorods structured with the length of about 200 nm, diameter of about 50 nm and high surface area (255.2 m2•g-1). The gas-sensing measurement results demonstrated that the sensor of porous α-Fe2O3 nanorods presented high response to ethanol vapor and which can response to ethanol vapor at low-temperature. Due to the exciting gas-sensing properties, the as-prepared porous α-Fe2O3 nanorods would be an ideal candidate for the application in ethanol sensors.

Abstract: Everyday engineering work is rife with uncertainty and complexity. Some of the uncertainty stems from highly variable natural phenomena such as wind and earthquakes. More prevalent is the uncertainty that arises from a simple lack of knowledge, especially in complex problems. This paper describes the key considerations of designing, manufacturing, and installing large amusement devices, with characteristics complex and uncertain by nature. A range of techniques for engineering decision-making and reasoning in the presence of uncertainty and complexity are described. The techniques may be applied throughout the design and manufacturing process, but are particularly effective in the early or conceptual stages, which are characterized by greater uncertainty than the latter design phases. The techniques described include qualitative reasoning, adaptive interval plotting, design space mapping, and design space reliability estimation. These methods allow the engineer to solve and visualize the design space. In contrast to engineering problem-solving approaches which find a single point configuration, a design space may include a large number of feasible solutions. The range of solutions may be used effectively in engineering decision making.

Abstract: Abstract.Based on the analysis of the concept and features of geological relics, this paper summarized the classification situation of Geological relics at home and abroad：there is no final conclusion, being in the stage of active exploration and development. There are several kinds of taxonomic hierarchies abroad, such as the American standards classification, UNESCO classification, and the British standards classification. Profound research concerning the classification of the geological relics has been made in the Chinese geological field. The author thinks that the basic scheme of classification which is put forward by Chen An-Ze and the China national geological park construction technical requirements not only includes all types of geological relics but also can be readily accepted by and easy for operation. To master the correct classification of the geological relics is favourable to the effective protection, rational exploitation and the Sustainable Development of geological relics.

Abstract: XPS analysis is used in studying surface chemical composition and structure of ultrafine raw Al powder and PVP/Al composite powder, respectively. It shows that: in PVP/Al composite powder’s surface, comparing with raw Al powder, relative content of Al decrease and relative contents of C and N increase. New chemical bonds are formed in PVP/Al composite powder’s surface, and it is certain that, these new chemical bonds derive from N atom and O atom of PVP’s pyrrole with Al atom in Al powder surface.

Abstract: To improve effectiveness of the production and manufacturing equipment and reduce the downtime, methods of effectiveness evaluation and integrated configuration and optimization for spare parts and repair equipments are studied. It makes that advanced manufacturing system is target and .efficient work percentage is the measure of effectiveness. On the basis of AMS effectiveness concept, measure parameter is confirmed and influence factors are analyzed considering operation concept, design concept, maintenance concept and supply concept. And then, AMS effectiveness simulation evaluation models are proposed and simulation evaluation system is designed and developed. Optimization model for the support quantities of the spare parts and repair equipments is given with constraints on efficient work percentage, and solved using marginal analysis algorithm. Finally, an example is provided to verify the validity of the methods.

Abstract: Aiming at the forest and wetland environment exploration mission, the mechanical structure and motion characteristic of a four-legs jumping robot are given particularly. Using the principle of virtual work states, the simplified dynamic model of one jumping leg is derived under some assumptions, and the relationship between the jumping height and thrust force of the leg is given and simulated. The simulation result have demonstrated the feasibility and validity of the theoretical analysis for the jumping robot.