Ga dopping GaxPb1-xTe(x=0.01-0.05) compounds were prepared by melting reaction method, and the in-c fluence of Ga content on the thermoelectric properties were investigated. The results showed that temperature dopende...
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Ga dopping GaxPb1-xTe(x=0.01-0.05) compounds were prepared by melting reaction method, and the in-c fluence of Ga content on the thermoelectric properties were investigated. The results showed that temperature dopendent carrier concentration increased and the hall mobility decreased with increasing Ga content, which indicated that the carrier scattering mechanism gradually changed from an acoustical scattering to the interaction between an acoustical phone and an ionized impurity scattering as x increased. All samples show n-type conduct and the absolute Seebeck coefficient values and the electric conductivity increase significantly with increasing Ga content.
The layered perovskite-type organic-inorganic hybrids (CnH2n+1NH3)2 MnCl4 (n=2, 4, 6, 8, 10, 12) were synthesized in solution and their structures were characterized. The results showed that the structures of the prod...
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The layered perovskite-type organic-inorganic hybrids (CnH2n+1NH3)2 MnCl4 (n=2, 4, 6, 8, 10, 12) were synthesized in solution and their structures were characterized. The results showed that the structures of the products were independent on the reaction initial temperature. The X-ray diffraction (XRD) patterns and the scanning electron microscopy (SEM) images of the products demonstrated that the hybrids crystallize very well and had typical layered structures. The interlayer distance of each hybrid was obtained from the XRD patterns. It was linear dependent on the carbon atom number in the organic chain and the organic chains interdigitated between the two adjacent inorganic sheets.
The solubility of layered perovskite-type organic-inorganic hybrids (CnH2n+1 NH3)2MCl4 (where M = Mn, Co, Cu, Zn;n = 2, 4, 6, 8, 10, 12) in seven kinds of solvent are obtained by atomic absorption spectrometry and tit...
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The solubility of layered perovskite-type organic-inorganic hybrids (CnH2n+1 NH3)2MCl4 (where M = Mn, Co, Cu, Zn;n = 2, 4, 6, 8, 10, 12) in seven kinds of solvent are obtained by atomic absorption spectrometry and titration method. The solvents are sherwood oil, cyclohexane, acetone, trichloromethane, DMF, methanol and water. The results show that the hybrids are prone to dissolve in polar solvent. This is attributed to the polarity of the hybrids. The hybrids disassembly dissolve when the interaction between the ammonium and the electron-donating group of the solvent is stronger than that between the organic and the inorganic parts in the hybrids. The series of M = Zn and Co have better solubility in the polar solvent than that of M = Mn and Cu and this is presumably because there are weaker interactions between the organic and inorganic parts in hybrids of M = Zn and Co.
In this paper, we presented a novel route for fabricating Ti 3SiC2-based and Ti3AlC2-based solid solutions with mixed powders of TiC/Ti/Si/Al in different molar ratios. The phase compositions of these solid solutions ...
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In this paper, we presented a novel route for fabricating Ti 3SiC2-based and Ti3AlC2-based solid solutions with mixed powders of TiC/Ti/Si/Al in different molar ratios. The phase compositions of these solid solutions were studied by XRD and the stoichiometrics of these compounds were determined to be Ti 2.63Si0.87Al0.13C2 and Ti 2.76Al0.78Si0.22C2 by EDS. We also investigated the electronic properties and mechanical properties of these two ceramics. The results showed that the dopants were not only beneficial to the fabrication of Ti3SiC2 and Ti3AlC2 but also improved the properties of these two ceramics.
Ca(Al1/2Nb1/2)O3 (CAN) and Ca(Fe 1/2Nb1/2)O3 (CFN) were prepared by solid reaction route. With the sintering temperature increased, the Q×f value of CAN changes from 7 200 to 17 500 GHz due to the changing of the...
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Ca(Al1/2Nb1/2)O3 (CAN) and Ca(Fe 1/2Nb1/2)O3 (CFN) were prepared by solid reaction route. With the sintering temperature increased, the Q×f value of CAN changes from 7 200 to 17 500 GHz due to the changing of the ordering degree, whereas, the dielectric constant and Q×f value of CFN decrease remarkably without structural changing. The reason of this phenomenon is that the difference in size of two B-site ions in CAN is larger than that in CFN. As a result, the ordering degree of CAN is more sensitive to the conditions of sample preparation, compared with CFN.
A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. S...
A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. Shen and S. Suresh [6]. In the present model, the functionally graded materials are considered as multilayered materials. Each layer consists of metal and ceramic with different volume fraction. The ceramic layer and the FGM interlayers are considered as elastic brittle materials. The metal layer is considered as elastic‐perfectly plastic ductile materials. Closed‐form solutions for different characteristic temperature for thermal loading are presented as a function of the structure geometries and the thermomechanical properties of the materials. A main advance of the present model is that the possibility of the initial and spread of plasticity from the two sides of the ductile layers taken into account. Comparing the analytical results with the results from the finite element analysis, the thermal stresses and deformation from the present model are in good agreement with the numerical ones.
Sodium potassium bismuth titanate (KNBT) slurry with high plasticity was prepared by the viscous polymer processing. The effects of milling time, bonding agent content, dispersant content, and pH value on the rheologi...
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Sodium potassium bismuth titanate (KNBT) slurry with high plasticity was prepared by the viscous polymer processing. The effects of milling time, bonding agent content, dispersant content, and pH value on the rheological properties were investigated by rheograms, and the optimal technological parameters were investigated. The KNBT fibers with improved properties were fabricated via an extruding machine. The results show that the slurry has optimal rheological behavior when the milling time is 16 h, the pH value is 7, the bonding agent content is 1.22% (in mass, the same below), and the dispersant content is 0.4%.
An analytical model of normal ballistic impact on the ceramic/metal gradient armor, which is based on modified Alekseevskii‐Tate equations, has been developed. The process of gradient armour impacted by the long rod ...
An analytical model of normal ballistic impact on the ceramic/metal gradient armor, which is based on modified Alekseevskii‐Tate equations, has been developed. The process of gradient armour impacted by the long rod can be divided into four stages in this model. First stage is projectile's mass erosion or flowing phase, mushrooming phase and rigid phase; second one is the formation of comminuted ceramic conoid; third one is the penetration of gradient layer and last one is the penetration of metal back‐up plate. The equations of third stage have been advanced by assuming the behavior of gradient layer as rigid‐plastic and considering the effect of strain rate on the dynamic yield strength.
The effect of ceramic/metal gradient armor's components characteristic on its impact‐resistant characteristic has been investigated by a new modified Alekseevskii‐Tate equation. The following researching work is...
The effect of ceramic/metal gradient armor's components characteristic on its impact‐resistant characteristic has been investigated by a new modified Alekseevskii‐Tate equation. The following researching work is done by the former model [1]: the effect of ceramic layer on the impact‐resistant characteristic, the effect of gradient layer on the impact‐resistant characteristic and the effect of metal layer on the impact‐resistant characteristic.
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