ZnO-B2O3-SiO2 additive with 0.55: 0.35: 0.10 molar ratio was added to Ba0.3Sr0.7TiO3 ceramics in order to lower the sintering temperature. The densification behavior, crystalline structure, microstructure, dielectric ...
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ZnO-B2O3-SiO2 additive with 0.55: 0.35: 0.10 molar ratio was added to Ba0.3Sr0.7TiO3 ceramics in order to lower the sintering temperature. The densification behavior, crystalline structure, microstructure, dielectric properties and breakdown strength of ceramics were studied. When 9 wt.% additive was mixed with pure Ba0.3Sr0.7TiO3 powder, the densification temperature of samples decreased from 1350°C to 1100°C compared with no additive system, and the sintered ceramics revealed dielectric properties at room temperature as follows: dielectric constant Εr = 413, dielectric loss tanδ = 0.00231 under 1 kHz and the breakdown strength Eb = 9.2 kV/mm.
One-dimensional (1D) anatase TiO2 nanostructures such as nanotubes, nanorods and nanobelts were synthesized by hydrothermal method. These TiO2 nanomaterials with different morphology were used to photocatalytically de...
One-dimensional (1D) anatase TiO2 nanostructures such as nanotubes, nanorods and nanobelts were synthesized by hydrothermal method. These TiO2 nanomaterials with different morphology were used to photocatalytically degrade gaseous benzene with P25 as a comparison. the prepared 1D TiO2 were characterized by XRD, TEM and BET, and the degraded efficiency of benzene and the production of CO2 were detected by Gas Chromatograph. The results showed that the morphology difference led to a significant variation of photocatalytic performance for degradation of gaseous benzene, with the activity order as follows: TiO2 nanotubes > TiO2 nanorods > TiO2 nanobelts > P25 TiO2.
Based on a facile glucose-guided hydrolyzing-heat-treating approach, urchin-like α-Fe2O3 nanomaterials with controllab.e morphology and crystallinity were prepared via adjusting the heat-treating temperature, and the...
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Based on a facile glucose-guided hydrolyzing-heat-treating approach, urchin-like α-Fe2O3 nanomaterials with controllab.e morphology and crystallinity were prepared via adjusting the heat-treating temperature, and their electrochemical performances were investigated. The results showed that changing the heat-treating temperature can effectively control the structure and electrochemical property of the as-made products. The urchin-like α-Fe2O3 nanomaterials obtained by heat-treating at 300°C, composed of a mass of the shuttle fibrous brunches, had higher initial discharge capacity(1475 mAhg-1) than those consisting of nanorods formed at 700°C. The above difference is ascribed to the urchin-like samples obtained at the relatively low heat-treating temperature, which, with low crystallinity, large SBET, and well-regulated porous, is helpful to the adsorption of electrolyte and the transport of lithium ion, resulting in the high activity and discharge-charge capacity.
In the present study, (1-x)(Sr_(0.88)Bi_(0.08))TiO_(3)-xBi(Mg_(0.5)Ti_(0.5))O_(3) (SBT-BMT) system was synthesized using conventional solid stateprocessing. X-ray diffraction (XRD) and SEM testings were employed to d...
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ISBN:
(纸本)9781457711626
In the present study, (1-x)(Sr_(0.88)Bi_(0.08))TiO_(3)-xBi(Mg_(0.5)Ti_(0.5))O_(3) (SBT-BMT) system was synthesized using conventional solid stateprocessing. X-ray diffraction (XRD) and SEM testings were employed to determine the phase constitution and microstructure of ceramics. SBT-BMT ceramics exhibited moderate dielectric permittivities ((epsilon)_(r)) (>1100 at RT) and low dielectric loss (0.07percent) over the temperature range from -20 to 200 deg C, with flat temperature coefficients of permittivity. In addition, SBT-BMT ceramics were observed to possess dielectric relaxation characteristics and energy densities, being on the order of 1.4 J/cm~(3) at 180 kV/cm was observed for the 0.8S_(0.88)B_(0.08)T-0.2BMT ceramics.
An approach of image matching for weld seam recognition is proposed based on the nonlinear dimensionality reduction algorithm Isomap. The target image to be recognized and the template images are considered as high di...
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Morphotropic phase boundary (MPB) of (0.8-x)PMT-xPbTiO3(PT)-0. 2PbZrO3(PZ) ternary system (x = 0.4) was studied by X-ray diffraction (XRD). It shows that by comparing with 0.4PMT-0.2PZ-0.4PT sample, after doping with ...
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Morphotropic phase boundary (MPB) of (0.8-x)PMT-xPbTiO3(PT)-0. 2PbZrO3(PZ) ternary system (x = 0.4) was studied by X-ray diffraction (XRD). It shows that by comparing with 0.4PMT-0.2PZ-0.4PT sample, after doping with Ni, c/a remains almost same (about1.009), while both c and a decrease indicating that lattice shrinks. Content of the tetragonal phase TP% of Ni-doped samples increase up to 81.1% when the doping limit of the nickel is reached (y = 0.05), and the dielectric constant Ε was found to increase up to 4570 when y = 0.05 and the Curie temperatures of doping samples were found to decrease from 175°C to 157°C.
A novel cast processing method, self-inoculation method (81M), was proposed. The process involves selfinoculants addition to the melt, then pouring the melt to mould through a multi-stream mixing cooling channel. In t...
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ISBN:
(纸本)9781622762866
A novel cast processing method, self-inoculation method (81M), was proposed. The process involves selfinoculants addition to the melt, then pouring the melt to mould through a multi-stream mixing cooling channel. In this paper, the process parameters were investigated. Results indicate that melt treatment temperature, addition amount of selfinoculants, slope angle of the cooling channel were the key factors for 81M process. The optimized parameters were obtained: melt treatment temperature is at 680 - 700°C;addition of self-inoculants is between 5wt% -7wt%;slope angle of the cooling channel is at 30°∼45°. Further analysis reveals that 81M changes the solidification microstructure of slurry by controlling the nucleation and growth of the primary phase in the melt.
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