Advanced Materials Research Vols. 433-440

Abstract: Thin CuInSi films have been prepared by magnetron co-sputtering, and followed by annealing in N₂ atmosphere at different temperatures. The structures of CuInSi films were detected by X-ray diffraction(XRD); X-ray diffraction studies of the annealed films indicate the presence of CuInSi, In₂O₃ and other peaks. The morphology of the film surface was studied by SEM. The band gap has been estimated from the optical absorption studies and found to be about 1.40 eV, but changes with purity of CuInSi. CuInSi thin film is a potential absorber layer material applied in solar cells and photoelectric automatic control.

Abstract: Using first-principles ultra-soft pseudo-potential approach of the plane wave based on the density functional theory (DFT), we investigated the surface properties for silicon carbide-derived structure (i.e. SiCDS). The calculated results show that, movement of C and Si atoms caused by Si removal results in surface structural changing, and a nanoporous surface feature can be observed on the SiCDS surfaces when more Si atoms are removed. The mulliken population analysis indicates that the Si removal leads to the stronger chemical bonds between C–Si and the formation of new stronger chemical bands between C–C. From the density of states, as the Si removal proportion increases, C2p becomes gradually dominant in the SiCDS surface state electrons. Moreover, the Si removal leads to evidently different band gaps, indicating that the conductivity for SiCDS surface structures can be adjusted through the Si removal.

Abstract: Thermal barrier coatings (TBCs) have been widely used by aero and land based gas turbines to protect hot section parts from oxidation and thermal loads. These coatings are generally consisting of multiple layers of coating (usually two) with each layer having a specific function. TBCs are generally deposited with air plasma spray (APS) or electron beam physical vapor deposition (EB-PVD) techniques. In this paper plasma sprayed TBCs were deposited on to 304 stainless steel substrates then ceramic surfaces were glazing with Nd-YAG laser. Metallographic examinations were applied to the samples to investigate microstructural changes in glazed ceramic layer. Both glazed and as-coated samples were subjected to oxidation tests to measure the high temperature oxidation resistance. The tests showed that, laser glazing is beneficial to oxidation resistance of TBCs. This improvement is attributed to sintering of zirconia layer which act as oxygen barrier and formed during glazing process.

Abstract: This paper has surveyed on education evaluation method and technology at home and abroad, and also researched on the statistics and analysis of internal education evaluation information processing technology. In view of the evaluation index system of secondary vocational education, it has established educational evaluation and analysis of statistical models based on decision tree algorithm, and also made a qualitative analysis and statistics of educational evaluation results, thereby providing the basis so as to obtain a qualitative analysis of educational evaluation in school, meanwhile, it provides a broad development prospects for the qualitative analysis quantitative analysis of educational evaluation results.

Abstract: the manual assembly line used for assembling a certain type of lighting panel was introduced. The manual assembly works were analyzed. The assembly workbench surface illumination of the assembly line was tested. According to the light source is linear form, the assembly workbench surface was divided into some rectangles firstly. The intensity of illumination of these rectangles centers were tested by the illuminance meter. The average illuminance was also calculated out. According to these values, the illuminance curves were draw, which were approximately parallel lines. Further, the time values of the workers complete the same assembly work in different illumination were measured. The analysis reveals that the high illumination or the low level of illumination will affect the work efficiency. The reasonable illumination interval values were found. The testing and analysis provide scientific basis for the adjustment of the workbench illuminance and the improvement of working environment lighting.

Abstract: In this paper, the peristaltic flow of a fluid of variable viscosity in a non uniform tube or channel lined with porous material is studied. This model is suitable for the pumps whose inner surface of the tube is rough, the roughness that arises due to corrugations plays an important role in pumping and in the biological systems such as blood vessels containing tissue region. The flow in the free flow of the tube is governed by Navier-Stokes equation and the flow in the permeable boundary is described by Darcy law. It is observed that the magnitude of peak pressure rise decreases with increase in flow rate and increases with increasing amplitude ratio and increasing Darcy number. It shows that the larger the permeability of porous medium, the greater the pressure rise against which the pump works. It is also observed that as the viscosity decreases the pressure rise increases and for different values of mean flow rate the frictional force exhibits opposite behavior to that of pressure rise. The trough in the frictional force increases with decreasing amplitude ratio and decreases with increasing Darcy number which shows that the increase in permeability of wall causes less frictional forces. The decrease in viscosity makes the peristaltic pump to work under less frictional force.

Abstract: To solve the irregular, poor efficiency and lowly reusable of resource, a structured framework based on the course of e-Learning is proposed. The concept knowledge and assisted learning knowledge are combined with course architecture. Based on this framework, course ontology is built according to the method of software engineering and the idea of reusable is adapted. The class hierarchy and the relationship between class are analyzed, and the course of computer network is combined as an example to create an instance.

Abstract: There have potential main-landslide and a undisturbed thin layer of siliceous rock under the left of Karst slope (K133+180), so it is easy to occur creeping slip surface because of gravity while excavating. Proceeding with geomechanics model and according to influence of heavy rainfall, two schemes proposed are analyzed by means of numerical simulation. Both the reinforcement with lattice beam and anchor cable and the reinforcement with anti-slide pile and cable satisfy stability of slope. But the second scheme has higher safety storage coefficient. And the result that the second scheme not only strength anti-shear ability but also change magnitude and trend of shear damage of potential landslide in slope is rewarded. So the restrain effect of the second scheme is better that of the first. According to engineering cost of two schemes, the cost of the reinforcement with anti-slide pile and cable is less than that of the reinforcement with lattice beam and anchor cable. So Karst slope (K133+180) is reinforced with the second scheme and it is stability undergoing strong rainfall. Experience of Karst slope (K133+180) can give useful guidance for similar projects in Karst terrain.

Abstract: In order to study the effects of velocity distribution of ultrasonic gas flow meter based on wall roughness, , a full developed turbulence model is established based on the theory of prandtl mixing length and flow loss coefficent λ has been calculated by using Colebrook friction correlation formula after analyzing time interval difference measuring method of ultrasonic flow meter. Through Matlab calculating and simulating velocity distribution in different conditions of wall roughness about the model shows and through Fluent simulating, velocity vector and pressure distribution in smooth and rough tube have been compared and analyzed. The experimental results shows that quantification of velocity distribution based on wall roughness can been solved with the model, and the analysis results have certain instructive significance to the development of ultrasonic gas flow meter.

Abstract: It is widely acknowledged that decisions made in the early design stages have a greater influence on the final product than those made in the later stages. In the early stages of a conventional design process, composite structures are designed without sufficient consideration being given to limitations of composite manufacturing process. Quite often some of composite designs cannot be produced with special performance requirement or cannot be produced at a reasonable cost. To resolve this drawback and achieve the manufacturable designs for composite product, a knowledge-based decision-making tool was introduced and applied to support the composite design optimization. Firstly, the current development of DFM techniques in composite domain, as well as the main problems in performing DFM for composites is analyzed. Secondly, some of key issues in the composite manufacturing process that should be considered during the composite design process are presented. And then, a knowledge-based DFM system for composite manufacturing process is proposed, focusing on the system decision task, the system framework and the flowchart. Finally, the system is illustrated with a case in autoclave process.