Applied Mechanics and Materials Vols. 66-68

Abstract: The low-carbon economy becomes a hot issue in every country after Copenhagen’s meeting, and Logistics enterprise is an important economic entity to achieve a low carbon economy, so how to effectively evaluate the effect of logistics enterprises and low-carbon benefits of emission reduction become a problem that really needed to solve. Therefore, it evaluated the effects of low-carbon benefits of logistics respectively from the economic benefits, logistics operational efficiency and CO₂ emission reduction by AHP. Based on it, logistics enterprise evaluation model of low-carbon benefits was built in the way of fuzzy comprehensive evaluation, and finally verified the effectiveness of the evaluation system with a case.

Abstract: Transportation industry is an important field to reduce greenhouse gas emissions and climate change. Scenario analysis of transportation industry can provide theoretical support to the formulation and implementation of carbon emissions reduction policy. In view of this, The transportation industry of Jiangxi province will be given into four departments including civil aviation, railways, highways and waterways, and it was used the LEAP model to set three scenarios in the different application of economic development mode and different traffic development mode, then forecasted the main carbon emissions of Jiangxi transportation industry in 2010-2030, and analyzed the result of forecasting. It shown that the way to ease the nervous energy supply and the pressure of carbon emissions, and achieve the sustainable development of energy and the environment, must be set the four departments of reasonable transportation distribution under the condition of different energy sources, and increase the scope of using the new energy and renewable energy.

Abstract: This paper proposes a non-cooperative game framework for concurrent tolerance design. The optimization issues in concurrent tolerance design for manufacture and assembly are discussed, and the mechanism of non-cooperative game for concurrent tolerance design is investigated. Finally, the algorithm is proposed to achieve concurrent tolerance design with non-cooperative game.

Abstract: This paper firstly introduces the principles of Stirling heat engines based on refrigerant phase-change circulation. This heat engines use two external heat reservoire. When the refrigerant in an engine cylinder absorbs heat from high-temperature heat sources, refrigerant is transformed from liquid to gas and the volume of the refrigerant expands to drive the piston apply work. When the refrigerant releases heat to low-temperature sources, the volume of the refrigerant shrinks. Therefore, phase change thermal engine technology using solar energy, industrial waste heat and heat produced by combustion of any fuel to work, no gas emissions, high thermal efficiency and environmental advantages. Thermal phase transition and thus the engine technology will be in the field of energy and power of a cutting-edge technology, great development potential and prospects.

Abstract: A humanoid robot arm with both shoulder joint and elbow joint is built. It is actuated by pieces of Mckibben muscles. Its skeleton-muscle formation is similar to the anatomical structure of the human arm. A pneumatic experiment system is established for supporting and testing the robot arm. The relationship between the robot arm actions and the Mckibben muscles is studied. Some main actions of the robot arm including the elbow bending, the whole arm arising and the rotating around the arm axis are realized.

Abstract: After the virtual NC real-time machining process control technology is studied, we design the NC code interpreter using the pipeline control method of overlapped resources in this paper. In order to improve the availability of interpreter, the design adopts the function pointer array and expression evaluation algorithm. By using two methods, the scalability is enhanced. Also the versatility is improved by using keywords information table to some extent. The system achieves a straight line and arc of the trajectory interpolation by the digital sampling algorithm and makes the efficiency improved by using RCS communication mechanism, windows thread and timing mechanism.

Abstract: By constant stress tensile test, the corrosion mechanism of high temperature QPQ treated 25CrMnMo steel specimen in H₂S environment was analyzed and discussed. The γ′-Fe₄N in the ε compound layer turns into corrosion substance in the test and expands. At the surface of the ε compound layer, the corrosion layer is visible. The compound layer breaks off in little blocks for volume expansion of the corrosion substance and the exterior tensile stress. The coefficient of diffusion of hydrogen atom in the ε compound layer is very low, that decrease the probability of the hydrogen-induced corrosion of high temperature QPQ treated specimens in H₂S environment.

Abstract: When the pressure of CO₂ is 2 MPa, through the autoclave corrosion tests of annealed N80 steel specimens in simulated oil field water solution at different temperature, the mechanism of corrosion and the change rule of corrosion resistance with the change of temperature were discussed. In the autoclave tests, some iron elements of the specimens become Fe²⁺ ions and the Fe²⁺ ions go into the solution, which results in the corrosion weight loss. Scaling develops because the CO₃^2- ions in the simulated oil field water solution react with iron elements of the specimen. To QPQ treated specimens, with the increase of temperature, the compactness of the scaling increase, the corrosion weight loss and the weight of scaling decrease. In the same temperature, the corrosion weight loss and the weight of scaling of QPQ treated specimens are both lower than that of untreated specimens.

Abstract: Studying how and how much the factors affect on the cooling rate of workpieces is very significant to improve the ability of vacuum high pressure gas quenching furnace. From changing the structure and technology of nozzle-type vacuum high pressure gas quenching furnace, by a large number of computer simulation, this paper discusses some factors affecting the cooling rate. By changing the number and distance of nozzles on each wind pipe, we can better control the cooling rate and uniformity of workpieces. From the perspective of improved process, the number, shape, size and placement of the workpieces have certain effects on cooling rate, in which the placement of the workpiece is very significant and significant. The simulation results for the further development of new high-pressure gas quenching vacuum device provide a theoretical basis.

Abstract: Rotating tube method for preparing Cu-Ca alloy semi-solid slurry was investigated. Compared the microstructure of slurry prepared through the tube and of untreated original sample, discussed evolution characteristics of microstructure flowing through the rotation tube, and analyzed effect of process parameter on microstructure. The results show that the semi-solid slurry of Cu-Ca alloy could be prepared through rotating tube process; the melt were hardly affected in the initial stage. The tube began to play a major part in the next stage and the melt were stirred effectively in the last stage; Spherical microstructures of Cu-Ca alloy slurry were obtained through controlling or adjusting the process parameters to control solidification conditions.