The KxNa1-xNbO3 nanopowders with cubic-like morphology and an average size of about 50 nm were synthesized by sol-gel auto-combustion method.And then,the ceramics were prepared and the phase transition,microstructure ...The KxNa1-xNbO3 nanopowders with cubic-like morphology and an average size of about 50 nm were synthesized by sol-gel auto-combustion method.And then,the ceramics were prepared and the phase transition,microstructure and electrical properties of the KxNa1-xNbO3 ceramics were investigated.Pure perovskite phases of the KxNa1-xNbO3 ceramics were confirmed by XRD patterns and the K0.50Na0.50NbO3 ceramics show the coexistence of orthorhombic and monoclinic structures.SEM micrographs show that all samples have bimodal grain size distributions and the number of the small grains decrease with increasing K+content in the bimodal grain size distribution system.The K0.50Na0.50NbO3 ceramics with the uniform grain size and the maximum density show excellent electrical properties withεr=467.40,tanδ=0.020,d33=128 pC/N and kp=0.32 at the room temperature,demonstrating that the properties of the K0.50Na0.50NbO3 powers prepared by sol-gel auto-combustion are excellent and the ceramics are promising lead-free piezoelectric materials.展开更多
Magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline ph...Magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. Magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe2O4.展开更多
Introduced the modulation scheme, function and mechanism of plasticity plaster slurry preventing coal spontaneous combustion. The applications show that the plasticity plaster slurry has good hygroscopicity and adsorp...Introduced the modulation scheme, function and mechanism of plasticity plaster slurry preventing coal spontaneous combustion. The applications show that the plasticity plaster slurry has good hygroscopicity and adsorptivity. To spray it on the coal wall of tunnel can shut off leakage wind fast and effectively. To press it into the coal body can absorb the heat and descend the temperature, surround the coal pieces, eliminate the possibility of the fiery district resuming combustion.展开更多
基金Project(21501007)supported by the National Natural Science Foundation of ChinaProject(2016GY-226)supported by the Industrial Science and Technology Plan in Shaanxi Province of China+1 种基金Project(ZK15044)supported by the Doctoral Scientific Research Starting Foundation of Baoji University of Arts and Sciences,ChinaProject(201610721039)supported by Undergraduate Training Programs for Innovation and Entrepreneurship,China
文摘The KxNa1-xNbO3 nanopowders with cubic-like morphology and an average size of about 50 nm were synthesized by sol-gel auto-combustion method.And then,the ceramics were prepared and the phase transition,microstructure and electrical properties of the KxNa1-xNbO3 ceramics were investigated.Pure perovskite phases of the KxNa1-xNbO3 ceramics were confirmed by XRD patterns and the K0.50Na0.50NbO3 ceramics show the coexistence of orthorhombic and monoclinic structures.SEM micrographs show that all samples have bimodal grain size distributions and the number of the small grains decrease with increasing K+content in the bimodal grain size distribution system.The K0.50Na0.50NbO3 ceramics with the uniform grain size and the maximum density show excellent electrical properties withεr=467.40,tanδ=0.020,d33=128 pC/N and kp=0.32 at the room temperature,demonstrating that the properties of the K0.50Na0.50NbO3 powers prepared by sol-gel auto-combustion are excellent and the ceramics are promising lead-free piezoelectric materials.
文摘Magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. Magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe2O4.
文摘Introduced the modulation scheme, function and mechanism of plasticity plaster slurry preventing coal spontaneous combustion. The applications show that the plasticity plaster slurry has good hygroscopicity and adsorptivity. To spray it on the coal wall of tunnel can shut off leakage wind fast and effectively. To press it into the coal body can absorb the heat and descend the temperature, surround the coal pieces, eliminate the possibility of the fiery district resuming combustion.
