Abstract: Advances in the preparation and research of CuInSe2 thin films solar cell are reviewed. The main attention is given to the effects of synthesis methods, including sputtering, spray pyrolysis, thermal evaporation, electrodeposition, dissolution-spin coating. And the structures, morphologies, compositions and photoelectrical performances of the CIS thin films synthesized by different methods are compared. The defects of different methods and research direction in the future were discussed.
Abstract: Glass filament reinforced composite materials have become an indispensable material in national economic construction. The main purpose of this project is to produce the spacer fabric adopting glass filament through changing weaving process. First glass filaments were treated with epoxy resin to prevent from its low bending rigidity. Second ground warps and binding warps were separately warped and double warp beams were used in the weaving. At the shed crossing point the height of heald frames was different between the top layer and down layer warps, then the drafting sequence of the top layer of warps, the down layer of warps and binding warps were adjusted. The cotton yarns were chosen as the selvage warps which have good wear resistance and uniform tension. The long and short beat–up method was used. Eventually 3cm thickness of glass filament spacer fabric is achieved. It is hoped that this work will provide meaningful help to the development of glass filament spacer fabric.
Abstract: This paper presents the use of water to wash sand approach can effectively achieve the purpose of washing sand chloride. Desalination of sea sand after a qualified construction sand, and the production process is simple, has a price advantage, saving fresh water resources, use as a building material has good prospects.
Abstract: The k·p interaction of the conduction band and valence band of InN materials was calculated in this paper. The nonparabolicity of the conduction band is more pronounced, because the conduction band feels stronger perturbation from the valence bands when Eg is smaller or EP is larger. The increase in absorption edge with increasing electron concentration was calculated by the dispersion relation. In the calculation, the conduction band renormalization effects due to electron interaction and electron-ionized impurity interaction are also taken into account. A good consistent picture is established in describing the conduction band of InN based on the k·p interaction.
Abstract: Polyimide (PI) films filled with K0.5Na0.5NbO3 particles at different weight 0wt%,5wt%,10wt%,15wt% and 20wt% had been prepared by in-situ dispersion polymerization process in this article. then we measured morphology and dielectric properties. when the mass fraction of KNN reach 20%, its dielectric constant achieve 4.9(100Hz) with the dielectric loss tangent value is less than 0.025 (100 Hz).it Shows the good insulating properties.
Abstract: Polyimide-Al2O3 nanocomposite films were prepared via simple mechanical blending of Polyimide and surface modified Al2O3, and Polyimide-TiO2 nanocomposite films were prepared by the polymerization process of adding tetrabutyl orthotitanate (TBOT) and the coupling agent isocyanatopropyltriethoxysilane (ICTOS) in polyimide. The three layers nanocomposite films were characterized by scanning electron microscope (SEM). The homogeneous dispersion is observed by the SEM when the concentration of Al2O3 is low. The electrical properties of the nanocomposite films were investigated as a function of the concentration of the Al2O3 nanoparticles. The results show that the dielectric constant and the dielectric loss (tan δ) of these films increased with the increase of the content of silica particles.
Abstract: Polyimide nanocomposite insulating materials are widely used in electrical and electron engineering owing to their outstanding electrical, mechanical, thermal, and wear-resistance properties. Polyimide/silica (PI/SiO2) nanocomposites have been prepared by the polymerization process of adding tetraethoxysilane (TEOS) and the coupling agent isocyanatopropyltriethoxysilane (ICTOS) in polyimide. The effects of SiO2 addition on the microstructure and the dielectric property of nanocomposite films were investigated. It was found that the silica particles were well dispersed in PI matrix and the sizes of SiO2 particles in the hybrid films range from 20 nm to 30 nm for 5-15 wt% SiO2 loading in the matrix. The dielectric constant and the dielectric loss (tan δ) of these films increased with the increase of the content of silica particles.
Abstract: With the transformation of China's urbanization and accelerated pace of urban agglomeration, increasing construction waste has brought the conflict between the development of urban and environmental degradation. To use recycled aggregate (RA) to a certain extent eased pollution on the environment. Because of the source of RA cause exist quality poor stability, dispersion and other shortcomings. By test, comparative analysis the differences indicators between recycled aggregate and natural aggregate, brick gravel content of recycled coarse aggregate performance indicators in particular made a crushing value performance test. As the research properties of recycled aggregate and adapted to the local grading standards provide a frame of reference.
Abstract: The piezoelectric effect was determined and the magnetization testing of diverse tourmalines was carried out in this paper. The results show that static voltage on both ends of tourmaline crystal enhances gradually with pressure enhancing, but there is no linear function between each other. At the very time when crystal breaks, the static voltage can reach a maximum value. The direction of the static voltage is reverse when giving and losing pressure. The performances of piezoelectric strength are as follows: Elbaite>Schorl>Dravite. The piezoelectricity on both ends of tourmaline crystal is stronger than that on cylinder surface, which is 3 ~ 4 times of the cylindrical surface. The piezoelectric strength of tourmaline crystal has nothing to do with its crystal volume but has something to do with the crystal surface streak. The performance is that the more limpid of the crystal surface streak is, the more obvious of the piezoelectric effect is. The overall tourmaline magnetization is weak. Magnetic susceptibility is a linear function of the refractive index and Fe-contents. Magnetic susceptibility of Schorl is greater than that of Elbaite. Saturation magnetization and remanence magnetic of Schorl are greater perpendicular to than parallel to C axis.
Abstract: This paper reports the analysis of efficient terahertz (THz) wave generation on the basis of quasi phase matching (QPM) difference frequency generation (DFG) in periodical GaAs by CO2 laser. The efficient second-order nonlinear susceptibility of GaAs was calculated by similar to the calculation it of uniaxial crystal. We calculated second-order nonlinear susceptibility for the incidence two pump lights with the same propagation directions. The result shown that, the incidence two pump lights with the perpendicular polarization directions and the same polarization directions were efficient to obtain high power conversion efficiency of THz wave.