Advanced Materials Research Vols. 228-229

Abstract: The grind test is detected curve of the grinding surface roughness of thin in use of three-dimensional contour in this paper, major influence factor in the accuracy of surface roughness is proposed in the analysis based on grinding surface roughness.Trend of the grinding surface roughness is simulated in Matlab. It is expected that best surface roughness can be obtained by selecting the appropriate cutting speed and feed rate for the material pair of workpiece and cutting tool.

Abstract: The Corex process, which consists of the upper reduction shaft and the melter-gasifier is an alternative ironmaking process to the blast furnace. The Corex melter-gasifier is a countercurrent reactor to produce liquid iron. Directly reduced iron(DRI), noncoking coal, and other additives are charged to the melter-gasifier at their respective temperature, and O2 is blown through the tuyeres. Moving bed of melter-gasifier is an important zone for reduction of iron oxide and melting of DRI, in which lump coal is a function as skeleton of moving bed replacing coke. A two-dimensional mathematical model was developed for describing gas flowing in the moving bed of Corex melter-gasifier. The gas velocity and pressure distribution were obtained. Further more, the effects of deadman porosity and cohesive zone, burden profile and height of moving bed above tuyere on the gas velocity and pressure distribution were studied.

Abstract: The damping capacity of Fe-Ga rods and sheets has been studied using a computer-controlled automatic inverted torsion pendulum instruments in a wide temperature range in a series of frequency. The frequency and temperature has different influence on the damping capacity of solidified Fe83Ga17 rods and (Fe83Ga17)97.25Cr2B0.75 sheets. The damping capacity of all specimens increased with frequencies. The solidified Fe-Ga rods showed an obvious low-temperature peak and a potential high-temperature peak with increasing temperature. However, the damping capacity of Fe-Ga sheets kept steady in a wide temperature range and then rapidly increased on further heating above 400°C. Damping capacity of about 0.02 was obtained in both Fe-Ga rods and sheets at temperatures from room temperature to 500°C. Thus, The Fe-Ga alloys are considered to be a class of promising high damping alloys.

Abstract: Naval airport aerial equipment support leads a vital status in aerial equipment support, a key point to support airport aerial equipment is the warehouse, but most existents are single and fixed, survival risk of the warehouse becomes an important threat to combat ability of airplane. Aimed at reducing risk of naval airport aerial equipment warehouse in wartime, a distributed system was given to optimize the naval airport aerial equipment storage solution. This system effects not only on reducing risks in wartime equipments supply, but also on equipment transferring support. Based on analysis of the necessity and feasibility of distributed storage, this paper introduce structure and operation process of the system in detail, and some constructive suggestion was given to naval airport aerial equipments storage.

Abstract: Ca3-xHoxCo4O9 (x=0.0, 0.15, 0.3, 0.45) samples were prepared using solid reaction and the effect of Ho doping on their high thermoelectric properties were investigated. The substitution of Ho for Ca resulted in an increase of both thermopower and electrical resistivity which could be attributed to the decrease of hole concentrations. The Ho-doped samples had lower thermal conductivity than Ca3Co4O9 due to their lower electronic and lattice thermal conductivity. The largest ZT values were attained in Ca2.7Ho0.3Co4O9 sample.

Abstract: It is necessary for Parallel Hybrid Electric Vehicle (PHEV) to distribute energy between engine and motor and to control state-switch during work. Aimed at keeping the total torque unchanging under state-switch, the dynamic torque control algorithm is put forward, which can be expressed as motor torque compensation for engine after torque pre-distribution, engine speed regulation and dynamic engine torque estimation. Taking Matlab as the platform, the vehicle control simulation model is built, based on which the fundamental control algorithm is verified by simulation testing. The results demonstrate that the dynamic control algorithm can effectively dampen torque fluctuations and ensures power transfer smoothly under various state-switches.

Abstract: The paper presents a mechatronic system designed to simulate the surroundings of night-driving roads in mesopic vision. Visual Performance in the mesopic range to define mesopic visual performance is thought of the most essential methods to research the mesopic vision. And there is no standard model to evaluate the mesopic performance. Therefore, the experimental system BJ-MV2 is designed to measure and record the reaction time. By changing the parameters of mesopic environment, we get a series of experimental data and calculate curve-fitting data. According to the curve, the tendency of reaction time appears clearly and BJ-MV2 is proved to be a reliable system for researching mesopic vision.

Abstract: This paper first of all provides the guiding principles for choosing assessment subjects for the environmental protection performance of local party and government officials: effectiveness, scientificalness and objectivity. Effectiveness includes usefulness, inexpensiveness, and urgency; scientificalness includes professionality, systematicness and representativeness; objectivity includes independence, political rationality and authority. After that, starting from these guiding principles, this paper discusses the process of how to choose the best performance assessment subjects according to the analytical model of stakeholder assessment subjects. And then characteristics of potential assessment subjects for the environmental protection performance of local party and government officials are analyzed. At last, through the analytical model of stakeholder assessment subjects and characteristics of potential assessment subjects for the environmental protection performance of local party and government officials, this paper makes a relative analysis of the best assessment subjects for the environmental protection performance of local party and government officials, and gets a conclusion that professional assessment institutions are the best choice.

Abstract: The effect of stepped aging treatment including two-stepped retrogression aging and retrogression reaging treatment on the mechanical properties, electrical conductivity and the microstructure of AA7085 has been investigated. Electron microscopy observations were used to analyze the microstructures and tensile fracture surfaces of AA7085 processed via various treatment schedules. Besides, X-ray diffractometer and differential scanning calorimeter were used to explore the thermodynamic factors of heat treatment. Through the investigation of the effect of the retrogression time on the properties and microstructure of AA7085, the optimized retrogression time was confirmed. The results of comparing retrogression aging and retrogression reaging treatment showed that through RRA treatment, higher conductivity and fracture toughness were gained. Through the optimized RRA treatment based on appropriate retrogression time, the tensile strength, elongation, fracture toughness and conductivity of AA7085 were raised to 660MPa, 12%,36.6MPa•m1/2and 38.1%IACS.

Abstract: The effect of postweld heat treatment (PWHT) on microstructure and properties of the heat affected zone (HAZ) in ASTM4130 steel fabricated by single-pass welding was investigated by weld thermal simulation test, optical microscope, transmission electron microscopy and scanning electron microscope. The results show that the subcritical HAZ (SCHAZ) toughness slightly decreases due to the aggregation and growth of carbides. Other HAZ toughness is significantly improved showing that the 650°C/1.5h PWHT is effective. The toughness improvement of the fine-grained HAZ (FGHAZ) and the intercritical HAZ (ICHAZ) is chiefly resulted from the complete decomposition of martensite and M-A constituent. Meanwhile, the supersaturation reduction of non-equilibrium microstructure and the relief of residual stress effectively improve CGHAZ toughness.