Advanced Materials Research Vols. 228-229

Abstract: Workpiece flipping equipment is widely used in hexagon workpiece multi face and work station processing. Hydraulic drive has advantages of easy linear motion achivement, high power quality ratio and rapid dynamic response, etc. It is an essential element of modern mechanical engineering and one of the key technologies of engineering controls. Hydraulic drive system of the hexagon workpiece flipping equipment was designed, the hydraulic system schematic was drawn, its working principle was analysed. The workpiece flipping was successfully achieved by using hydraulic technology, it obtained good results in practical applications.

Abstract: Direct extrusion forming process, two-stage extrusion forming process and composite extrusion forming process were designed for manufacturing a titanium alloy tapered piece. Comparison of the forming loads under the different processes were investigated using Deform finite element method(FEM).Considering the load size, energy consumption and production efficiency, the best extrusion forming process was eventually selected. The result showed that: In the direct extrusion forming process, the maximum load was 11.5MN, and the die life was short; In the two-stage extrusion forming process, the maximum load was only 4.25MN, but it had a poorer effectiveness and higher energy consumption because of two-stage forming processes. In the composite extrusion forming process, the maximum load was only 38.6% of direct forming process, and it had a higher effectiveness and lower energy consumption because of one-stage forming processes.

Abstract: Nacre of molluscan shells has evolved through millions of years to a level of perfect microstructure and excellent mechanical properties. Compressive strengths of nacre parallel and vertical to the surfaces of platelets are tested as 420MPa and 500MPa, respectively. The fracture surfaces are characterized by SEM and the fracture processes are analyzed. The toughening mechanism of compressive loading parallel to the aragonite platelet mainly includes cracks deflection, platelets disengagement, platelets crunch, platelet interlock, organic matrix bridging and mineral bridge. Comparably, the toughening mechanism of compressive loading vertical to the aragonite platelet mainly includes platelets crunch, organic matrix deformation and mineral bridges collapse. Additionally, the propagation of crack deflections in compressive loading parallel to the aragonite platelet is different from that in bending fracture of cross section.

Abstract: We study the effect of dispersion medium and dominated evaporation on the drying process and pattern of thin liquid layer colloidal suspention. Panasonic camera is used to capture the drying process and macroscopic pattern. It is shown that drying patterns are sensitive to the dispersion medium. As the volume ratio of ethanol in aqueous ethanol colloidal suspension increases, the evaporation rate increases, and film in the center becomes smaller and thinner, obvious broad-ring pattern can be observed. We suggest that difference in dispersion medium changes the evaporation rate, which has a direct proportional variation with strength of Marangoni convection. Furthermore, convection strength has great influence on self-assembly of colloid particles and the pattern formation of colloidal suspension. We design two simple experiments to change the evaporation rate and convection strength in order to verify the conclusion above. Broad-ring patterns with spray-like round edge at higher evaporation rate are obtained. Uniform film forms at lower evaporation rate.

Abstract: On the basis of analyzing the properties of the Camellia oleifera peel and seed, for the purpose of solving the problem of the separation of peel and seed, a device has been designed based on the aerodynamic principles. The single factor experiment has been carried out to research how the feeding angle, feeding height, fan inclination and fan height can influence the seperation. The result shows that the feeding angle has a significantly effect on the separation, the suitable angle is 40°; the feeding height has a significantly effect on the separation; when the feeding height is 200mm, the peel in the seed zone is the least, but the seed in mixing zone is the most, when the feeding height is 300mm, the seed in the mixing zone is the lesat, but the peel in the seed zone is the most, so in the actual production, the feeding height need to be comprehensive considered; the fan inclination has a significantly effect on the separation, the suitable inclination is 15°; the fan height does not have a significant effect on the separation.

Abstract: Firstly introduce compose structure of semi-automatic figuration machine of the grind material,and the motion it must be realized.Based on working demand of pneumatic actuator,analysing input and output signals of electricity control equipments,drawing a work process sketch map.According to the logic design method and step of electricity control circuitry,draw a logic relation chart.Reasonable dispose operation component work zone and write out operation component logic expression,then change the operation component logic expression to electricity control circuit diagram,finally point out the advantage of this design method.

Abstract: By taking the examples of the GEM model that widely applied in the research field of cluster competency, the article puts forward a new GEM model in connection with some influence factors of the knowledge innovation ability of University Science Parks based on the overview of the GEM model. Moreover, the article carries out a questionnaire survey into 11 National University Science Parks in Shanghai and discusses their knowledge innovation abilities through quantitative research. The article calculates the domain scores and the GEM values of 11 National University Science Parks in Shanghai and the calculating results helps us objectively to learn about the status of their knowledge innovation abilities at present.

Abstract: The surface lanthanum element plays a key role in emission mechanism of Lanthanum-contained cathodes. In order to gain insight into the relation between cathode emission properties and the cathode surface La/O ratio, lanthanum-rich film cathodes were prepared in situ by using a set of equipment, specially designed to cathode research, which connected with an Auger electron spectrometer (AES) and pulse laser deposition system. Electron emission properties and surface compositions (lanthanum and oxygen) of the cathodes are investigated experimentally. Experiment results indicate that film cathodes are lanthanum-rich film cathode, there has remained unchanged on film composition in different depth; the cathode emission properties are determined intensively by the surface atomic La/O ratios, the higher the La/O ratio gets, the better the emission property reaches. The excess active Lanthanum is crucial element to the improvement of emission properties.

Abstract: The domain wavelength is the most important colorimetric parameter of tested LED, it decides the LED color quality. The data acquisition system is build of linear CCD, monochromator，and PCI data acquisition card, which can obtain the chart of distribution value of 1urninous intensity and color coordinate of LED with LabVIEW. This paper present measurement method based on the table method, the measurement method is looking-up two domain wavelengths which distance is 1nm through slope which get from testing LED color coordinate and white light LED coordinate, and calculate the domain wavelength of testing LEDs using LabVIEW and mathematic interpolation, the measurement error of domain wavelength is 1 nm.

Abstract: A new finite element analysis method of driver drum is introduced in this paper, conveyor belt is introduced in analysis model, and the effect that bearing imposed on drum is treated as spherical constraints. The drum is analyzed under the coalition of assembly load and ultimate torque load using the paper method as well as the traditional method, and the results between two methods are compared. The analysis results show that the danger points are on the hub inner and the weld seam between spoke and hub, the comparison shows that the analysis results by the paper described method are smaller than the traditional method results by 10%. The load imposing ways described in this paper are more consistent with the actual work process, and the analysis results are more accurate and reliable.