Advanced Materials Research Vol. 1081

Abstract: The cubic WO₃ powder was prepared by sol-gel method with WCl₆ as the soure of tungsten and P₁₂₃ as the structure-directing agent. The crystalline phase and microstructure of the powder were characterized through TG-DSC, XRD and SEM techniques, respectively. It was found the powder annealed at 250°C for 4h mainly was cubic WO₃ with a little monoclinic phase. The SEM micrographs revealed the powder has a petal shape with about 200 nm mean particle diameter. The photocatalytic activity of the powder was evaluated by methyl orange as mode compound to photocatalytic degradation under UV light irradiation. The results show the cubic WO₃ powder has much higher photocatalytic activity than the monoclinic phase.

Abstract: A new kind of organic prepolymer containing cobalt phthalocyanine ring (Co-FOM) was prepared by reaction from ferrocenyl organic magnetic prepolymer (FOM) and cobalt chloride. The structure of Co-FOM was characterized by Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectrophotometry (UV-vis). The magnetic properties of Co-FOM exhibited stronger magnetism than FOM at room temperature. The maximum saturation magnetization of Co-FOM reached to 15.8 emu/g at the magnetic field of 5000 Oe. Meanwhile, Co-FOM had one resonance peak for dielectric loss and two resonance peaks for magnetic loss in 0.5-18 GHz. Furthermore, this kind of magnetic material had a strong reflection loss at higher frequency (around 17 GHz). So Co-FOM will have potential application in electromagnetic shielding area.

Abstract: A one-step carbon thermal method was used to prepare LiFePO4/C particles by using normal Fe₂O₃, LiH₂PO₄ and sucrose as raw materials. The effect of H₂ content in the sintering atmosphere of N₂ on the morphology and the electrochemical performance were investigated. LiFePO₄/C materials were characterized by X-ray diffraction, scanning electron microscopy and the elemental analyzer. The results show that the precursor sintering under the atmosphere of 8%H₂+N₂ exhibits the highest electrochemical capacity (162.3 mAh/g at 0.1C) .

Abstract: The electrochemical behavior of pure Mg in H₃PO₄ acid (0.42 M) and phosphating solution (0.42 M H₃PO₄+0.34 M ZnO) was investigated through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curve and XRD measurements. The results show that Mg has higher corrosion resistance in the phosphating solution than that in the H₃PO₄ acid which may be due to the relative protective phosphating film on the surface.

Abstract: This paper uses the industrialization production device to study the factors that affecting the performance of fly ash products. Through adopting the appropriate material ratio and technological parameters, the load-bearing standard bricks with large admixing amount of fly ash were successful developed. The mixing amount of fly ash has reached about 50%, and the bricks were got the production application in the industrialized device which annual output is 400 million pieces. The product performances are referred to the requirements specified in JC 239-2001, and the compressive strength reach 16.6 MPa and the breaking strength reach 3.8 MPa. The product has the low thermal conductivity and qualified freeze-thaw resistance, dry shrinkage. The products were got widespread popularization and application in the building construction of Qinghai-Tibet Plateau.

Abstract: Liquid nucleation in an ideal silicon crystal is studied in the framework of Lindemann criteria by using molecular dynamics simulations. Lindemann parameter is traced during the transition. It is found that when Lindemann parameter reaches a critical value δ_L*=0.328, liquid emerges, and when 9.4% atoms in the crystal exceeds the critical value, a complete melting is achieved.

Abstract: Using the flux processing technique, the undercooling of pure silver melts could reach to 205K. Combining the Differential Scanning Calorimeter (DSC) technique, the specific heat of pure silver melts was measured, which showed a linear dependence on temperature in the range of the obtained undercooling from 0 K to 205K. The related thermodynamic properties of silver, such as the entropy change, the enthalpy change and the Gibbs free energy difference between the undercooled melt and the solid phase, were derived from the measured specific heat. The results showed that the model of Singh-Holz can reveal the reality of the non-equilibrium solidification more accurately than other models.

Abstract: Using classical non-equilibrium molecular dynamics simulations (NEMD), the interfacial thermal resistance and thermal rectification of nitrogen-doped zigzag graphene (NDZG) are investigated. Two different structural models about nitrogen-doped graphene are constructed. It is found that the interfacial thermal resistance at the location of nitrogen-doping causes severe reduction in thermal conductivity of the NDZG. Thermal rectification of the triangular single-nitrogen-doped graphene (SNDG) decreases with increasing temperature. However, thermal rectification is not detected in the parallel various–nitrogen-doped graphene (VNDG). These results suggest that SNDG might be a promising structure for thermal device.

Abstract: The heating furnace in CSP plant of WISCO has a lightweight lining which is built by all fiber templates. In light of its good thermal insulation performance and short service life, the lining material for heating furnace was optimized in this article by using heat transfer calculation while the thickness stays light and the insulation performance stays good. The castable was applied to substitute for lightweight fiber materials to prolong the service life of heating furnace lining. Also, this article shows a contrast analysis of heat insulation layer while using different insulation material: the fiber felt, nanoinsulation board and super hydrophobic insulation board. The effect on the temperature of external shell and heat loss was analyzed and discussed. The results generate a new design of material composition, which not only prolongs the service life of heating furnace lining, but also reduces the cost.

Abstract: In order to analyze the effect of RDX-based thermobaric explosive on strain rate, the stress-strain curves with different strain rates were measured by using the Split Hopkinson Pressure Bar (SHPB) and resistive strain testing technology. The different strain rates were obtained by changing the length to diameter ratio (L/D=0.46~0.92) and speed of the bullet (10~18m/s). The results showed that it is obvious to change the strain rate by the change of the L/D and speed of the bullet with different functional relationship; RDX-based thermobaric explosives have the evident strain rate: failure stress and strain are increased with the increase of strain rate.