Advanced Materials Research Vols. 941-944

Abstract: A detailed first-principles study of electronic structure and optical properties of Nd-doping ZnO with various concentrations of Nd was performed using density functional theory. The results show that the band gap of Nd-doping ZnO slightly widens with the increasing Nd concentration, this is because the conduction band undergoes a greater shift toward the lower-energy region than the valence band, which is agreement with experimental results. Furthermore, in comparison to pure-ZnO, the Fermi level shifts into the conduction band after Nd-doping ZnO. And the calculated result of imaginary part of dielectric function of Nd-doping ZnO shows that there is a sharp peak in the lower-energy region, which is due to the electrons transition between d-d orbital of Nd atom.

Abstract: A novel D-A type molecule based on central fluorene unit and aldehyde group termini has been designed and constructed. Optical spectra show that, from the solution to the solid state, the absorption and fluorescence spectra of the compounds are red-shifted. Moreover, a red-shift of the absorbance maxima and the emission maxima of the compounds were observed due to the electron-accepting groups. Blue light-emitting properties with purity color range at 412–468 nm were also obtained. Thus, the target compound is expected to be a promising pure blue light-emitting material for applications in organic light-emitting diodes (OLEDs).

Abstract: The hierarchically urchin-like magnetic hydroxyapatite (HAp)/Fe₃O₄ composites were hydrothermally fabricated and were used for the removal of Pb (II) from aqueous solutions. The morphology, composition and properties of the magnetic HAp/Fe₃O₄ composites were fully characterized and investigated. The results showed that the HAp/Fe₃O₄ composites had a 3D urchin-like hierarchical structure with Fe₃O₄ nanoparticles dispersed among the building units. These urchin-like composites had high surface area and good magnetic responsibility. The equilibrium removal process of Pb (II) by the composites was correlated well with the Langmuir model, resulting in the maximum adsorption capacity of 223.71 mg/g. The high adsorption capacity and good magnetic responsibility suggest that the multifunctional composites have great potentials for heavy metal ion removal.

Abstract: The complex permittivity and permeability of Dravite, Elbaite, ZnO and Dravite/ZnO complex powder are analyzed in this paper. Within the frequency range of 2~18 GHz, the dielectric losses of these four materials are in the sequence of: 0 ≈ Dravite ≈Elbaite < ZnO < coated powder = 0.211. The complex powder's magnetic loss decreases gradually with the increase of frequency. The magnetic loss is between 0.05 and 0.15 at the frequency ranging from 2 to 6 GHz. The research has shown that Dravite/ZnO complex powder exhibits some microwave absorbing capability, which may widen the application of tourmaline in the field of environmental depollution.

Abstract: In induction heating, one is often brought to solve the system of coupled equations:Thermal physical caracteristics (calorific capacity and thermal conductivity.) and electromagnetic (permeability, susceptibility, reluctivity, permittivity, electric conductivity) depend on the temperature for the first, the temperature and the magnetic or electric field for the seconds.The modelisation of the permeability according to the only applied field magnetic abounds in the scientific literature. But, its modelisation as a function of the applied field and also temperature is rather rare.The goal of this work is thus to establish this double modelisation.In this intention, we will use the heat equation, the Maxwell's equations and the function of Brillouin, wich is the physical and formally basis of this modelisation.

Abstract: High temperature, low temperature, water stability and fatigue test were done for three types of modified asphalt mixture of intermediate course used in high-grade highway engineering in Northeast region. The asphalt mixture design scheme with excellent performance suitable for application of intermediate course was selected for reference in Northeast area.

Abstract: The curve to detect concrete compression strength with resiliometer for area of Southeast province is established and studied by experiment and data analysis. The curve provides protection for the supervision and inspection of the structural engineering quality and concrete quality in the area.

Abstract: Finite element analysis is carried out on the dynamic splitting tensile mechanical properties of reinforced concrete with LS-DYNA. The impact of strain rate and reinforcement ratio on the dynamic tensile strength and failure mode of reinforced concrete is considered in the calculation. The result shows that the form of reinforcement and reinforcement ratio has a greater impact on the failure mode and tensile strength of concrete. The dynamic splitting tensile strength of reinforced concrete has a certain strain rate effect and its splitting tensile strength increases with the strain rate; the splitting tensile strength of reinforced concrete also increases with its reinforcement ratio.

Abstract: Road runoff was the major contribute to water body pollution. According to the cement concrete pavement flush was evaluated by artificial rainfall model, the experiment indicated that the runoff coefficient of cement concrete pavement was 0.85, the flush coefficient of dissolvable pollutant of road runoff flush model k was 0.082, and the flush coefficient of indissolvable pollutant of road runoff flush model k was 0.057. With the increasing cumulate runoff ratio, the initial flush coefficient k_n was decreasing. The emission of 90% dissolvable pollutant and of 30% indissolvable pollutant was removed by 30% runoff.

Abstract: This paper deals with the behavior of concrete columns actuated by SMA wires winding around the column’s cylindrical surface, when the concrete column are constrained and driven in circumferential direction by the SMA wires, the column’s ultimate bearing capacity and axial deformation are mainly studied. Both theoretical research and finite element simulation are carried out. The results indicate that, the SMA’s limited recovery in reverse transformation by heating can generate circumferential prestress, which will improve the concrete column’s ultimate bearing capacity and control its deformation, so as to realize the concrete column’s recovery strengthening.