Search

The crystal structure of GdFeMn alloy has been investigated by using X-ray powder diffraction (XRD) followed by Rietveld refinement technique, differential thermal analysis (DTA) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) techniques. XRD results showed that annealed GdFeMn alloy was a single phase of Gd6(Fe0.5Mn0.5)23 compound, with Th6Mn23-structure. SEM/EDS results and Rietveld refinement revealed that GdFeMn alloy was not really a new ternary compound as reported, but a solid solution Gd6(Fe0.5Mn0.5)23 which was only a point between Gd6Fe23 and Gd6Mn23. It was also found from DTA measurement that a reaction, Gd (Fe0.5Mn0.5)2 → liquid (rich Gd) + Gd6(Fe0.5Mn0.5)23, had taken place above 650.81 oC, and the educed Gd existed in educed part of GdFeMn sample. The results demonstrated the real structure of the GdFeMn compound as reported was Gd6(Fe0.5Mn0.5)23 compound.

With the arrival of knowledge economy era and the shortening of product life cycle, information technology and the rapid development of e-commerce with each passing day, and customer gradually increasing expectations, the competition among enterprises are gradually entering the supply chain competition, Now enterprises have begun to realize that effective supply chain management, which would have to assess supply chain performance. However, most of the evaluation methods used in our country using expert analysis to evaluate the contractor's financial indicators to determine the final contractor. This method is not only too subjective, but also cuts off the correlation between the indicators. A quantitative management innovation classified performance model of supplier performance evaluation based on clustering and K-NN classification is proposed to classify suppliers. Then on the basis of above analysis, the contractor of misclassification is identified by the K-NN method. Finally, an evaluation and selection case is presented to verify the practicability and effectiveness of the model. The method not only overcomes the above shortcomings, but also reflects the contractor's comprehensive level objectively and fairly. The results show that it can provide an important reference for the fair and impartial evaluation of the project contractor as an important method for decision makers to select the contractor.

Mn100-xFex (x=50, 58) alloys were prepared by spark plasma sintering (SPS), and the structure, magnetostriction and magnetic properties of the polycrystalline Mn100-xFex alloys were investigated. The results of XRD and SEM showed that the as-cast and annealed samples presented a single face center cubic γ-phase, which is austenite structure. The magnetic measurement showed that Mn100-xFex (x=50, 58) alloys annealed at 700oC were a typical ferromagnet at low temperature and there was a gradual transition from the ferromagnetic phase to the paramagnetic phase in a wide temperature region (about 150-250K). The magnetostriction for the annealed samples, measured by strain-gauge bridge up to 3T, was ~100 ppm at 300K, but the results was chaotic. The results are not in agreement with the results reported. The further research on the mechanism of the magnetostriction is needed.

For C-Si-Mn low carbon HSLA(High Strength Low Alloyed) steel, the influence of microstructure and properties were researched on the different annealing processes. The result showed that the microstructure at room temperature of the steel were polygonal ferrite, island martensite and punctate bainite. With the increase of the annealing temperature, the content of martensite and bainiteincreased and the content of ferrite decreased. Accordingly, tensile strengthincreased from 1069MPa to 1498MPa, and the elongation decreased from 13.8% to 5.1%. With the increase of the overaging temperature, tensile strength decreased from 1315MPa to 1152MPa, and the elongationincreased from8.5% to9.8%. Finally, the optimum annealing process obtained that the annealing temperature was 820°C for 80s, slow cooling to 680°C, water quenching to room temperature, the overaging temperature was 280°C for 300s and air cooling to room temperature. The material obtained higher tensile strength and better elongation.

Molybdenum (Mo) film is deposited by Ion Beam Assisted Deposition (IBAD) on the 316L steel substrate surface in this experiment. The micro structure and nanohardness of the film are tested by Scanning Electronic Microscope (SEM) and nanoindentation tester. The tribological behaviors of Mo film under ZDDP and MoDTC lubrication are evaluated by SRV test machine. The tribo-film formed on the worn surfaces is investigated by X-ray photoelectron spectroscopy (XPS) to find out the tribological mechanisms between the Mo film and the two additional additives. The result shows that Mo film not only has friction reduction property but also has wear assistant property under ZDDP and MoDTC lubrication. As element Mo has advantage on promoting the deposition of these two lubricating additives.

E-Business is changing the traditional business model which takes the Internet as main carrier. Simultaneously, the knowledge becomes the essential factor to enterprise productivity in the new E-Business pattern, the enterprise struggles the superiority development to competitive advantage based on the knowledge. on the base of correlation theories review, This paper analyze the handicap existed in customer knowledge management, make full use of virtual enterprise of the brand-new type enterprise operation mode, and construct virtual enterprise based on lead user ,and then put forward the integration innovation operation mode and measures to resolve enterprise customer knowledge management problem based on E-Business. This pattern may help the enterprise to be quicker, grasp the market opportunity accurately, improve the product and the service unceasingly, enhance enterprise's core competitiveness which might provide reference for research and practice work in relevant fields.

Phase transformation of austenite continuous cooling process in low carbon high strength sheet steel has been researched by DIL805 thermal mechanical simulate. The Austenite continuous cooling transformation (CCT) diagram of steel has been determined by dilatometry and metallography. With the increase of cooling rate, ferritic transformation, perlitic transformation, bainite transformation and martensitic transformation have produced in the organization. Mathematical equations of phase transformation point-cooling rate and phase variable-cooling rate have been established and phase transformation model of high fit degree has been gained by regression calculation. The results show that calculated value and experimental value are nearly similar, so the phase transformation model is feasible.