Advanced Materials Research Vol. 709

Abstract: we proposed a scheme for simulating the electronic and thermoelectric properties of polycrystalline ceramics. The simulation results show that the ground state electrons are easily confined in the largest grain. In addition, with the increasing average grain size, the Seebeck coefficient decreases while the electrical conductivity increases monotonically. The simulation results agree well with the available experimental results. Therefore, the proposed model is proved to be a promising approach for thermoelectric investigations.

Abstract: The flux growrh method is employed to grow the Yb:LuPO4 crystal using lead pyrophosphate Pb2P2O7 as the high-timperature solvent. The infrared spectroscopy(IR) was tested to determine the purity of the obtained crystal. The absorption spectra of the 5% Yb-doped Yb:LuPO4 crystal was measured at room temperature. Three absorption peaks that located on 985nm, 976nm and 953nm were found, and the absorption cross sections on the absorption peaks were calculated respectively. The results shows that Yb:LuPO4 crystal has potential to be applied as laser material.

Abstract: Mn doped graphene-based dilute magnetic semiconductors (DMS) are investigated using the first-principle calculation based on density functional theory. In this paper, the Mn-C bond length, formation energy and magnetic moment are calculated in different doping systems and their density of states is made a detailed analysis. It is found that Mn-doped graphene has strong ferromagnetic properties and the magnetic moments of graphene supercells are different with the impurity concentrations. These supercells of a Mn atom substituting a C atom are increasingly stable with extending cells and the 11×11 supercell possesses the biggest magnetic moment of 3.8μB in these systems. The analysis of the density of states indicates the magnetic properties of Mn-doped graphene derive from the p-d exchange mechanism.

Abstract: The method of growing ADP crystal along {100} direction rapidly has been studied. A platform was used to grow ADP crystal to improve its utilization and optical quality. Chemical etching was used to analyze the dislocation mechanism. It indicates that the crystal grown in the defined crystallographic direction {100} could be qualified for optical application. The grown crystals were characterized by optical transmission spectra. It can be observed that the transmittance of the sample grown by our method reached 85% in the visible region.

Abstract: A new mixed laser crystal, Yb0.006Y0.923Lu0.071VO4, has been successfully grown using the Czochralski method. X-ray powder diffraction analysis shows that the crystal has ZrSiO4 structure. Density, thermal expansion coefficients, specific heat and thermal diffusion coefficients were measured, and the thermal conductivity coefficients were determined.

Abstract: Magnetic properties of 6H-SiC doped with transition metal (TM) atoms are calculated using the density functional theory method (DFT). It is shown that TM doped in a 6H-SiC host may have both magnetic and nonmagnetic states. From the figures of their density of states (DOS) and partial density of states (PDOS) and to compare the energy differences between ferromagnetic and nonmagnetic states, we demonstrate that Cr and Mn-doped 6H-SiC emerge a half-metallic ferromagnetic state, Co and Ni-doped 6H-SiC create very little magnetic features, while Fe-doped 6H-SiC is in the nonmagnetic state. We also calculate the energy differences between ferromagnetic and antiferromagnetic of Cr, Mn and Fe-doped 6H-SiC in the doping concentration (8.34%). It is found that the energy of the antiferromagnetic state is lower than that of the ferromagnetic state.

Abstract: In order to do research on the motion time of plasma spray gun in powder particle flame plating, the paper made an analog computation to powder particle motion process of plasma spray gun by establishing powder particle equation of motion and thermal evolution equation, after that the motion time of powder particle in electric arc was obtained. It provided advantageous theoretical basis for plasma spray gun design after confirming the computation results by making use of high-speed photography technology.

Abstract: The strength and elongation, the unevenness and the number of hairiness of the Newdal fiber/fine polyester blended yarn are tested. By the analysis of these results, the optimum blended ratio of the blended yarn is determined.

Abstract: In this paper, moisture transfer properties were studied on different weave structure and different weft of polyester-cotton fabric. Under the same conditions, the moisture absorption rates and permeability rates were measured on the different weft of plain weave, satin weave, twill fabrics. The influence law of the fabric density and structure on moisture absorption and permeability of polyester-cotton fabric were concluded. The results showed that under the same temperature and humidity conditions, the moisture absorption rates and permeability rates of the fabrics were both increased with the weft decreased. Moisture absorption rates and permeability rates of the plain weave fabrics were minimum, which of the satin weave fabrics were maximum, of the twill fabrics were moderate.

Abstract: A series of poly(vinyl alcohol)/silk fibroin nanofibers loaded with 10 wt.% vanillin were successfully prepared from aqueous solutions via electrospinning. The morphology, weight loss and swelling ability of the nanofibers were characterized. The controlled release characteristics of vanillin in the nanofiber mats were evaluated by in vitro release test. Vanillin-loaded nanofibers had smooth surfaces like drug-free nanofibers, and showed thinner diameter than the latter. The release rate of vanillin in the nanofiber mats decreased with the increment of silk fibroin content, so by regulating the content the drug release could be controlled. Moreover, after treated with ethanol the nanofiber mats showed better stability against disintegration in water and sustained release rate of vanillin than untreated mats.