The effects of the modification of electrode/ceramic interfaces through a chemical solution deposition-derived PbO buffer layer on the fatigue endurance of lead zirconate titanate（PZT） thin films were *** grain size...
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The effects of the modification of electrode/ceramic interfaces through a chemical solution deposition-derived PbO buffer layer on the fatigue endurance of lead zirconate titanate（PZT） thin films were *** grain size and the surface roughness of the PZT films increased through PbO interfacial ***,the PZT films with PbO interfacial modification had a better crystallographic structure and no evident secondary phases were *** the remanent polarization and dielectric constant were reduced,the fatigue endurance was *** on the results,the mechanism for the fatigue endurance improvement was discussed.
Catalytic effects of NiCl,TiC and TiN on the dehydrogenation/rehydrogenation characteristics of LiAlH were investigated by pressure -content-temperature(PCT),X-ray diffraction(XRD),differential scanning calorimatory(D...
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Catalytic effects of NiCl,TiC and TiN on the dehydrogenation/rehydrogenation characteristics of LiAlH were investigated by pressure -content-temperature(PCT),X-ray diffraction(XRD),differential scanning calorimatory(DSC),and field emission scanning electron microscopy(FESEM).The doped samples exhibit dehydrogenation at much lower *** with NiCl,TiC and TiN induce a decrease in the decomposition of first step by about 50-65℃compared to that of as received ***,amount of hydrogen release is significantly higher for TiC additions than that of samples doped with TiN and *** desorption results at 125℃reveal that dehydrating rate of doped alanate is much faster than that of pure ***,TiN and NiCl dopants show the reabsorption of about 1.9 wt.%, 1.3 wt.%,and 1.1 wt.%,*** and FESEM analyses suggest that both TiC and TiN are stable during the ball milling as well as the dehydrogenation *** the contrary,NiCl reacts and causes the partial decomposition of Li alanate during the ball milling process.
作者：
Pan YongJun潘勇军Xie HongQuan陈勇Chen Yong崔丽College of Material Science and Engineering
Wuhan Textile University Wuhan 430074 China 武汉纺织大学材料科学与工程学院 武汉 430073 Department of Chemistry Huazhong University of Science and Technology Wuhan 430074China 武汉理工大学复合材料国家重点实验室 武汉 430070 State key laboratory of advanced technology for materials synthesis and processingWuhan University of Technology Wuhan 430070 China
Graphene was prepared and used as an adsorbent for removal of cationic red X-GRL from aqueous solutions. The physico-chemical properties of graphene were characterized by the transmission electron microscope (TEM), th...
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Graphene was prepared and used as an adsorbent for removal of cationic red X-GRL from aqueous solutions. The physico-chemical properties of graphene were characterized by the transmission electron microscope (TEM), the Brunauer-Emmett-Teller (BET) specific surface area measurement, atomic force microscope (AFM), and Raman microscope. The adsorption properties of cationic red X-GRL onto graphene were studied as a function of pH, adsorbent dosage, contact time, and temperature. Kinetic data were well fitted by a pseudo second-order model. Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Equilibrium data agreed very well with the Langmuir model. Thermodynamic studies showed that the adsorption was a spontaneous and endothermic process.
Polycrystalline samples of Sr5PrTi3Ta7O30 （SPTT） and Sr5EuTi3Ta7O30 （SETT） compounds were prepared by high-temperature solid-state reaction method and their formation, structure and dielectric properties were stud...
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Polycrystalline samples of Sr5PrTi3Ta7O30 （SPTT） and Sr5EuTi3Ta7O30 （SETT） compounds were prepared by high-temperature solid-state reaction method and their formation, structure and dielectric properties were studied. They are found to be ferroelectric phase of filled tetragonal tungsten bronze （TB） structure at room temperature and undergoes diffuse type of ferroelectric-paraelectric phase transition around 34 ℃ and 31 ℃, respectively. At 1 MHz SPTT exhibits high dielectric constants of 177 and low dielectric losses of 3.5×10^-4 and SETT has high dielectric constants of 125 and low dielectric losses of 2.4×10^-3.
Density functional perturbation theory, combined with quasi-harmonic approximation theory and the Debye theory, has been used to calculate the thermal conductivity of the double-perovskite perovskite slab–rocksalt la...
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Density functional perturbation theory, combined with quasi-harmonic approximation theory and the Debye theory, has been used to calculate the thermal conductivity of the double-perovskite perovskite slab–rocksalt layer oxide compounds L2SrAl2O7 (L = La, Nd, Sm, Eu, Gd, and Dy), a promising class of high-temperature thermal insulators. The predicted properties are compared with experimental data and show excellent agreement from room temperature up to 1000 °C. This indicates that the methodology is an effective approach to calculating the thermal conductivity of complex, defect-free crystal structures.
Pb0.95Sr0.05[(Mn1/3Sb2/3) 0.06(Ni1/2W1/2)x(Zr 0.49Ti0.51)1-x-0.06]O3 (PMS-PNW-PZT) (x = 0.01∼0.04) were prepared by using traditional technique with solid reaction process. The effects of PNW contents and sintering t...
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Pb0.95Sr0.05[(Mn1/3Sb2/3) 0.06(Ni1/2W1/2)x(Zr 0.49Ti0.51)1-x-0.06]O3 (PMS-PNW-PZT) (x = 0.01∼0.04) were prepared by using traditional technique with solid reaction process. The effects of PNW contents and sintering temperatures on microstructure, dielectric and piezoelectric properties of PMS-PNW-PZT ceramics were investigated. When the amount of doping content was about 2 mol% and the sintering temperature was 1250°C, the optimum values of buck density, mechanical quality factor, dielectric loss, piezoelectric constant, dielectric constant, planar coupling coefficient were obtained as follows:ρ = 7.54 g/cm3, Qm = 2800, tanδ = 0.27%, d33 = 360pC/N, Ε3T3/Ε0 = 1990, kp = 0.63, which can meet the requirements of piezoelectric transformers.
Structure characterization and elastic properties of tetragonal phase of zirconia have been investigated by density functional theory (DFT). The XRD spectrums and vibration properties of Raman active modes of T-ZrO2 w...
Structure characterization and elastic properties of tetragonal phase of zirconia have been investigated by density functional theory (DFT). The XRD spectrums and vibration properties of Raman active modes of T-ZrO2 were calculated and the results were compared with references. The calculated results have showed researchers may distinguish cubic and tetragonal phases used XRD spectrums in the 2 range of 72.5°-75.5°, 122°-129° and 138°-148°. The calculated vibrated properties of Raman active modes as follows: the modes of Zr-O stretching are 262.6, 486.2, and 641.6 cm−1 the modes of Zr-O bending and O-O coupling are 344.4 and 606.9 cm−1 and the modes of Zr-O-Zr or O-Zr-O bending is 141.2 cm−1.
The thermal expansion behavior of semiconductor single-crystal nanowire arrays is of importance for their applications in electronic and optoelectronic nanodevices. We prepare hexagonal ZnS single-crystal nanowire arr...
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The thermal expansion behavior of semiconductor single-crystal nanowire arrays is of importance for their applications in electronic and optoelectronic nanodevices. We prepare hexagonal ZnS single-crystal nanowire arrays growing along the [110] direction via electrodeposition. The thermal expansion properties of the as-prepared ZnS nanowires have been studied by in situ x-ray diffraction method. The thermal expansion coefficient （TEC） of the ZnS nanowires decreases consistently from room temperature to 225℃ where it reaches a minimum value, and then increases rapidly. The average TEC in the studied temperature range is 4.74 × 10-6/℃, which is smaller than that of the conventional bulk counterpart.
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