Abstract: The upconversion (UC) luminescence properties of phosphor Tm3+/Yb3+ co-doped Gd2Mo3O9were investigated in detail. Tm3+/Yb3+ co-doped Gd2Mo3O9was prepared by solid-state reaction method using Na2CO3 as flux and characterized by powder X-ray diffractometry. Under 980nm excitation, Tm3+/Yb3+ co-doped Gd2Mo3O9has exhibited a weak red emission near 651nm and strong blue emission at 476nm. Tm3+/Yb3+ co-doped Gd2Mo3O9phosphor has been considered as a better candidate in solid-state lighting applications.
Abstract: In this paper, the Fe-9Si-6Al soft magnetic composite has been prepared via powder particles coated with aluminum oxide and silicone. The magnetic properties and microstructure of Fe-Si-Al SMC has been investigated. Results showed that the powder particles surface contained a thin insulating layer made of aluminum oxide and silicone. After annealed at 800°C for 60min, the particles of component are all by themselves and the insulating layer is not destroyed. The Fe-Si-Al SMC has excellent magnetic properties. The magnetic permeability is steady with the frequency changing at 5kHz-100kHz range.
Abstract: Electrospinning of PVA can be performed from aqueous solution leading to the generation of homogenous nanofiber webs. PVA nanofibers are generally required to be modified because of its poor stability in water. The water stability of PVA nanofibers was improved by heat treatment in this paper. The test results showed that the crystallinity of the PVA nanofibers increases after heat-treatment. The crystallinity which is the largest increased by 12% when they were treated at 150°C for 10 min. The heat-treated fibers don’t dissolve in water and show certain degree of agglutination and swelling. PVA nanofibers were taken as the inner layer of the sandwich structure purification material prepared with the hot pressing technology. The filtering experiment showed that the filtration properties were better when the area density of PVA nanofibers is 2.5g/m2. The filtration efficiency of materials and retention rate of PVA nanofibers decreased after being used for 5 times.
Abstract: In this paper, the fracture process of WCp/Cu functionally graded materials(FGMs) was investigated. The used materials were fabricated by powder metallurgy using tungsten carbide(WC) particles and copper(Cu) matrix, and had functionally graded layers. In order to investigate the fracture process of the FGM, three-point-bending tests of rectangular specimens were carried out. From the results, it can be seen that the bending performance of FGM structures with increasing WC content from head layer to the bottom layer excels that of FGM structures with decreasing WC content in three-point-bending tests.
Abstract: Now-a-days natural Fibers are employed in various engineering applications because of their high tensile strength, low thermal expansion, high strength to weight ratio and good corrosion resistance. In this paper, woven roving composite laminates are prepared to produce automotive panel boards. Even though, various methods are available for preparing composites like Pultrusion method, filament winding method and hand layup method, hand lay method is used in this paper. The bundles of woven roving are alkalized at concentration between 1.2 and 6% of NaoH. Then, the treated fibres with increased strength are used as reinforcement with Epoxy LY556 resin with HY951 hardener under room temperature. The tensile analysis is conducted for the specimens like plain specimen, specimen with circular central hole and specimen with rectangular central hole. The results show that plain specimen is having more strength followed by circular hole and then rectangular hole specimens. It suggested that the case industry can make near optimal circular hole for its components by replacing rectangular hole.
Abstract: A novel non-halogen flame retardant APESP, cyclotriphosphazene containing six aminopropyltriethoxysilicone functional groups N3P3[NH(CH2)3Si(OCH2CH3)3]6, was synthesized by menas of SN2 nucleophilic substitution reaction, using hexachlorocyclotriphosphazene(HCCP) and 3-aminopropyltriethoxy-silane (KH550) as material. Firstly the industrial grade HCCP was purified through recrystallization and sublimation. Then the reaction process was investigated to prompt the yield, and the optimum reaction conditions were as follows: triethylamine as acid-binding agent, tetrahydrofuran as solvent, HCCP/KH550/triethylamine molar ratio 1:7.2:7.2, dripping time: 1 hour, temperature: 67°C and reaction time: 20h. Maximum APESP yield reached 94.3%. The chemical structure and purity was characterized by element analysis, Fourier-transformed infrared spectroscopy (FTIR), mass spectrum, gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) analysis. The results showed that the structure of synthesized product is consistent with the theoretical structure, in which the chlorine atoms were completely substituted. The charge distribution calculation of HCCP and KH550 confirmed the reaction mechanism.
Abstract: CMP is commonly recognized to be the most effective technique of achieving global planarization. SiO2 and CeO2 abrasives are the most commonly used in CMP slurries due to their good polish performance. To consider respectiveSubscript text advantages and synergistic effect, preparation of SiO2/CeO2 composite nanoparticles with core/shell structure have become a hot topic in CMP field. We introduced the preparation technology of SiO2/CeO2 and their applications in CMP in recent years.
Abstract: Isatin, an endogenous compound existent in many organisms, shows a wide range of biological activities. In this paper, we like to report the design and synthesis of several isatin derivatives through the acetalization and N-Acylation. Six newly synthesized compounds were characterized on the basis of 1H NMR, and those compounds were determined using two different human cancer cell . Anti-cancer activity showed those compounds IC50＜50 μm.
Abstract: The reactive polymer fiber with high adsorption capacity and good mechanical properties, RPF-AA, was prepared by the processes of pre-treatment, modification of the commercial PAN fiber. In order to improve the repeating circles of the semiconductor titania photocatalyst and broaden its applications, fine titania particles immobilized in RPF-AA fibers (TiO2/RPF-AA) were prepared successfully at room temperature by a dip-coating method. Tetrabutyl orthotitanate (TBOT) was hydrolyzed in presence of hydrolysis control agent tetrabutylammonium hydroxide (TBA)OH and the TiO2 fine particles were crystallized under microwave (MW) irradiation. The X-ray diffraction (XRD) analyses indicated that the fine particles obtained with MW irradiation have much higher crystallinity with a single phase anatase compared with the non-MW-treated solution. The continuous layers of titania were found on RPF-AA fibers by the scanning electron microscopy (SEM) analysis. The fibers with anatase coatings showed high photocatalytic property and better repetition on the photodegradation of MB. The coated fibers were scattered on the water surface and the catalytic reaction proceeded. After completion the decomposition process, the coated fibers were easily recovered using a filter.