Advanced Materials Research Vols. 476-478

Abstract: Nonmagnetic metal-matrix composite (MMC) coatings were fabricated by laser cladding with direct injection of WC-FeNiCr powder onto the N1310 nonmagnetic steel matrix. Laser cladding was conducted using a Trumpf6000 CO2 laser. The WC-FeNiCr MMCs coating was characterized using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The phase constitution in the laser cladding was identified by x-ray diffraction (XRD). No pores or macro-cracks have been found at the interface indicating good metallurgical bonding between the coating and the N1310 nonmagnetic steel matrix. Magnetic measurements were carried out with vibrating sample magnetometer (VSM) at room temperature. The MMC coating was nonmagnetic and with a relative permeability of 1.004. The XRD analysis confirmed the presence of an austenitic γ-(Fe, Ni), Cr0.19Fe0.7Ni0.11, Fe3W3C, WC and W2C phases in the laser clad layer.

Abstract: In this paper, the method for plane wave ultrasoft pseudopotentials of first-principles is adopted to calculate electronic structures of three models including VN crystal, the absence of V atoms and the replacement of V atoms by Si atoms by the VASP software package. On the basis of the optimized VN’s lattice constant, the energy band structures and density of states(DOS) curves of those three models are analyzed. The results show that the 3d electrons of V atoms determine that VN crystal is a conductor. The crystal lack of V atoms forms a peak caused by the empty position near the Fermi level. Its valence band energy level splits and the ability to form bonds reduces to be a metastable phase structure. The formation of solid solution interface due to Si atoms replacing V atoms leads to the peak value of total DOS to decrease, the distribution of electrons to be more diffuse and the ability to form bonds to strengthen.

Abstract: Using experiment method, ZnO films are prepared at various substrate temperatures, annealing temperatures and oxygen pressures. The films are examined by X-ray diffraction, atomic force microscope. Through researching the structural and optical properties of ZnO films, optimized conditions for growing ZnO films are obtained. The results suggest that high quality ZnO films with high c-axis orientation can be prepared by pulse laser deposition.

Abstract: The magnetic field and vibration signal of electromagnetic direction valve can be detected real-timely by a non-intrusive on line detection device, which can use to monitor working state of the valve. A method of fault detection and diagnosis for electromagnetic direction valve from the signal detected by the non-intrusive on line detection device is presented in this paper. The wave frequency bands energy analysis method is adopted to distinguish the electromagnetic direction valve’s state, and the vibration signal are decomposed by three-layer wavelet packet which wavelet basis is db10. The fault identification method is based on BP artificial neural network (ANN), which is the most well-known three-layers BP ANN whose input and output layers have 8 and 3 neurons respectively.

Abstract: Polyethersulfone (PES) hollow fiber membranes have been widely used in many fields, such as ultrafiltration, microfiltration, reverse osmosis, liquid/liquid or liquid/solid separation, gas separation, hemodialysis, and so on. In this paper, the sheet PES hollow fiber membranes were prepared and post-processing of membranes were studied. Suction method and pressing hot water method can both increase pure water flux of membrane. Suction method is more efficient and with a smaller time to increase pure water flux. After membrane was soaked into glycerol/water solution, pure water flux of membrane increased greatly and the length shrinkage ratio of the membrane was more smaller.

Abstract: The oil filter materials are frequently subjected to abrading and all kinds of friction and making the materials suffered from damage,consequently,the property and service life of the filter materials is reduced.So the purpose of this thesis is to research the tensile performance of the automobile oil filter material and according to constant speed tensile test to measure the macro fracture characteristics,tensile property in the process of before and after tensile testing,tensile fracture form and the math expression.Then compared the breaking strength,breaking elongation,elongation at break and breaking work of these ten oil filter materials.Hope that through the study on the tensile performance of the oil filter materials and summarizes the damage mechanism and tensile fracture form,in order to provides a new way to develop the new material.

Abstract: Titanium dioxide thin films have been prepared from tetrabutyl-orthotitanate solution and methanol as a solvent by sol-gel dip coating technique. The thermal properties of TiO2 gel were analyzed by thermogravimetry and differential thermal analysis (TG-DTA). Structural properties of TiO2 thin films at different heat treatment temperatures were analyzed by X-ray diffraction (XRD), Infrared Raman spectroscopy and scanning electron microscopy (SEM). The results show that the TiO2 thin films crystallize in anatase phase at 400 °C and the crystallinity of anatase phase was improved with increasing temperature. The TiO2 thin films crystallize into the anatase-rutile phase at 600 °C and further into the rutile phase at 800 °C. The photocatalytic performance of TiO2 film was tested for the degradation of 2×10-5 mol/L Rhodamine B. The degradation of Rhodamine B solutions reached 0.9×10-5 mol/L after irradiated for 8 h under UV light. The TiO2 thin film exhibited relatively high photocatalytic activity towards degrading Rhodamine B.

Abstract: The ZnO and ZnO:Ce thin films were prepared by DC reactive magnetron sputtering. The structure, surface morphology, optical and photoluminescence properties of ZnO:Ce thin films were investigated. The XRD results indicated that all the samples exhibited a hexagonal wurtzite structure. The surface morphology of the films was sensitive to the Ce concentration. All the films had a higher average transmittance (more than 85%) in the visible region and a strong absorption near the band-edge of ZnO. The photoluminescence properties of the Ce-doped ZnO thin films were also studied. Blue emissions were observed from the ZnO:Ce thin films. Our results indicated that the photoluminescence properties of ZnO thin films doped with low Ce concentration were related to the intrinsic transition of Ce3+ ions. However, when the Ce concentration increased, Zni also played an important role.

Abstract: Preparation of TiO₂ thin films by pyrolysis was investigated. Butyl titanate and ACAC were dispersed in ethanol solvent, then transferring the whole solution on the glass substrate and getting TiO₂ films by vaporizing and decomposing the chelating butyl titanate at a certain temperature. The surface morphology of the prepared TiO₂ films was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM), showing the influences on the surface morphology at different preparation temperatures and chelant amount.

Abstract: 3D (three-dimensional) laser scanning can be used to collect spatial location of points rapidly and abundantly, and obtain three-dimensional coordinates of the target surface, which provides new technical means for the rapid creation of three-dimensional image model of the object. A three-dimensional modeling study on spatial object was carried out using the spatial data captured via ground-based 3D laser scanner in the Hui-Quan substation. The experiment result shows that rapid 3D visualization modeling on buildings can be achieved via the methods and procedures mentioned above. It has solved that the traditional equipment and the measuring technique is insufficiency in the special domain. It will bring the application mode and technical advantage, which tradition mapping way can not have. A platform for three-dimensional model of the substation can be achieved for the resources, landscape, security, environmental management and other social resources of digital, networked and dynamic visualization.By taking WuXi Hui-Quan Substation as the research object, building 3D models by Three-dimensional laser scanning technology and embedding 3D-GIS, Meanwhile, combining existing 2D-geographical spatial data, data preparation, construction of 3D-model, 3D-visualization, space inquiry and analysis, information management are given systematic analysis and research. In the end, in the programming environment of C#2.0, Skyline software is employed with its open Application Programmed Interface (API), which constructs 3D-scenes and 3D-terrain models of WuXi Hui-Quan Substation and comes to the realization of 3D-visualization, property inquiry and edit of Attribute data.