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With the goal of lightweight and strong microwave absorption, polyaniline/aminopropyltriethoxysilane/silicon carbide (PANI/APTES/SiC) nano-composites with hierarchical architecture were fabricated through a facile in situ polymerization method. Herein, the SiC powders were modified with APTES in advance to achieve a more uniform envelope by PANI. The composites with different thicknesses of PANI layer and adjustable dielectric properties can be obtained by altering the PANI ratio. For the optimized sample, the minimum value of reflection loss is − 51.34 dB at 13.92 GHz with a thickness of 1.9 mm and the effective attenuation bandwidth is in a broad range from 12.19 to 17.45 GHz (bandwidth of 5.26 GHz). The outstanding absorption properties are closely related to the suitable impedance matching and the multiple loss mechanisms. more...

We report experimental investigation on the ferroelectricity and electric field-induced strain response in LiNbO 3 -doped 0.94(Bi 0.5 Na 0.5 )TiO 3 -0.06BaTiO 3 (BNT-BT) piezoelectric ceramics. At room temperature, a large strain of 0.6% (at 70 kV/cm) is achieved in the 2.5%-LiNbO 3 -doped BNT-BT, higher than that of commercially-utilized Pb(Zr,Ti)O 3 . The corresponding piezoelectric coefficient d * 33 reaches 857 pm/V, which is high among these of BNT-based ceramics at room temperature. Further study indicates that the superior piezoelectric properties are realized at the ferroelectric-relaxor transition temperature T F-R , which is pushed to room temperature with 2.5% LiNbO 3 doping. This indicates that large electromechanical response can be induced via delicate mixing of the ferroelectric rhombohedral phase and the polar nanoregions (PNRs) relaxor-ferroelectric tetragonal phase. more...

The flower-like CuS/RGO composites were synthesized via a facile one-pot solvothermal method, which displayed outstanding photocatalytic activity for Methylene blue(MB) degradation under Xenon lamp irradiation. The as-prepared samples were e examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence(PL) spectra, scanning electron microscopy (SEM), transmission scanning electron microscopy (TEM) and UV–vis optical absorption spectroscopy to determine the properties of the samples, respectively. The results illustrated that RGO had an important effect on the photocatalytic performance of CuS/RGO for dyes. The flower-like CuS/RGO composites exhibited better photocatalytic activity and excellent recyclability in degrading Methylene blue(MB) solution in comparison with pure CuS. The photocatalytic degradation efficiency of MB reached up to nearly 80% after 140 min irradiation, which was more than four times higher than that of CuS, indicating that CuS/RGO composites could have a great potential application in organic pollutants removal. more...

The flower-like CuS hierarchical structures were synthesized by solvothermal method. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared(FTIR) spectroscopy, UV–vis optical absorption spectroscopy and thermogravimetric analysis (TGA). The results demonstrated that the as-prepared flower-like CuS with the diameter of 1–5 um was pure hexagonal phase CuS and had well-defined flower-like structures. (1) The as-prepared CuS was proved to possess high photocatalytic performance with band gap of 1.45 eV. The degradation rate of Methylene blue (MB) was up to, 98.26%, 100% after 30 min under UV and visible irradiation. (2)The UPF of cotton fabric treated with CuS reached up to 174 compared with the original untreated fabric with the UPF 20.62. (3) The electromagnetic interference shielding effectiveness (EMI SE) of CuS coating was up to 27–31 dB when the content of CuS increased to 28.6%wt in the frequency of 300 KHz–3 GHz. Furthermore, the influence of reaction conditions on the morphology of the as-prepared CuS was investigated systematically and the possible formation mechanism of the CuS hierarchical structure was also proposed. more...

Magnetic and electronic properties of S- and N-doped CrO 2 are studied by using the first-principle projector augmented wave potential within the generalized gradient approximation. The optimized lattice constants for CrO 2 agree well with the previous work. With increasing S doping (N doping), the lattice constants of CrO 2− x S x (CrO 2− x N x ) ( x =0.5, 1 and 1.5) all increase (decrease), While these compounds remain the tetragonal structure. CrO 1.5 S 0.5 , CrO 1.5 N 0.5 and CrON compounds remain the half-metallicity, while the band gap is determined by different factors. It is also found that the change of the total magnetic moment with equivalent atom S doping in CrO 2 compound is small except for x =1. more...

Structural, magnetic and electronic properties of C-doped monoclinic ZrO2 have been studied by using the first principles projector augmented wave potential within the generalized gradient approximation as well as taking into account on site Coulomb repulsive interaction. The optimized structures show the lattice constants a, b, c and monoclinic angle β of C-doped monoclinic ZrO2 change slightly. While the lattice constants a, b, c and monoclinic angle β of C1-doped monoclinic ZrO2 are smaller than that of C2-doped monoclinic ZrO2. The total magnetic moment of C-doped monoclinic ZrO2 is mainly contributed by the atomic magnetic moment of C atom. For C atom substituting O atom, the systems are found to be half-metallic material and usable in magnetoelectronic and spintronic devices. more...

Using the first principle projector augmented wave potential within the generalized gradient approximation as well as taking into account the on-site Coulomb repulsive interaction, the structure, magnetic and electronic properties of N-doped monoclinic ZrO2 have been studied. For N doping in different oxygen sites, the lattice constants a, b, c and monoclinic β angle are almost equal. The N-doped m-ZrO2 is a ferromagnetic half-metallic material. The total magnetic moment is mostly contributed by the N atom. Spin splitting occurs between the partial DOS of the up-spin and down-spin channels for N 2s and 2p states, as well as the hybridization appears between N 2p and O 2p states. The strong ionic bonding character in N-doped m-ZrO2 is revealed in the substantial charges transfer from Zr atoms to N and O atoms. more...

This paper analyzed temperature field and temperature stress of cement concrete pavement under periodic variable low temperature using finite element method modeling technique in ABAQUS. And discussed the effect of wind speed, surface thermal conductivity coefficient on temperature field. Cracking and warping at the joint of concrete panel was simulated to analyze pavement deformation and mechanical characteristics. Results show that at lower temperature, concrete face will appear horizontal longitudinal displacement, causing the appearance of cracking; and warping effect will appear at the concrete panel, leading to concrete pavement void. It is revealed that dowel bar has not occurred plastic deformation, that is, bending strength meets the requirements. more...

Micrococcus luteus Z3 was immobilized in polyurethane foam and its ability to degrade nitrobenzene was investigated. Batch experiments showed that polyurethane-foam-immobilized cells possessed a higher degradation capacity. Compared to freely suspended cells (FSC), immobilized cells degraded nitrobenzene more efficiently under alkali and acid conditions, as well as higher temperature. Kinetic studies revealed that higher concentrations of nitrobenzene were better tolerated and more quickly degraded by immobilized cells. Moreover, in the presence of NaCl (≤10%, w/v) immobilized cells exhibited better tolerance toward salinity. Therefore immobilization of Z3 in polyurethane foam could be a promising method for treating nitrobenzene industrial wastewater, especially with high salinity. more...

Pb0.97La0.02Zr0.95Ti0.05O3(PLZT) antiferroelectric thin films were prepared on Pt (111)/ Ti/SiO2/Si (100) substrates by a sol-gel process. The influences of annealing temperature on the structures and dielectric properties of the PLZT antiferroelectric thin films were investigated. And the phase structure and crystal orientation were studied by X-ray diffraction analyses (XRD). The antiferroelectric characterization of the PLZT thin films annealed at different temperature was demonstrated by P(polarization)-E(electric field) and C(capactitance)-E(electric field) curves. The maximum polarizations for the films annealed at 650°C, 700°C and 750°C were 35μC/cm2, 42μC/cm2and 47μC/cm2, respectively. The temperature dependent of the dielectric constant and loss was measured under the frequency 1, 10, 100 and 1000 kHz. The films annealed at 700°C have high (100)-preferred orientation and excellent dielectric properties. more...

By the sol-gel process, Pb0.97La0.02(Zr0.95Ti0.05)O3(PLZT) antiferroelectric (AFE) thin films with different thicknesses were successfully deposited on Pt(111)/Ti/SiO2/Si(100) substrates. The phase structure of the PLZT antiferroelectric thin films was studied by X-ray diffraction (XRD) analyses. The electric field-induced AFE-FE phase transformation behavior of the PLZT thin films，was examined by polarization versus field (P-E) and relative permittivity versus field (C-E) measurements, with priority focused on thickness-dependent phase switching field. The current by the polarization and depolarization of polar in the PLZT films was measured through current density-electric field (J-E) measurement. With the increase of film thickness, the maximum polarization less and less, the maximum current density is increasing. more...

The flow state of both the solid and gas phase in the fluidized-bed photo-oxidation reactor for Shenfu coal was studied by cold-model tests. The results showed that the appropriate pipe diameter, particle size of coal, and the coal addition for the gas-solid fluidized-bed reactor were 22 mm, 60-80 mesh, and 10g, respectively. more...