This paper discusses the present status of, and future perspectives on nano Traditional Chinese medicine (TCM) by describing the concept, its methodologies, preservation, drug effect and pharmacological study. The exp...
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Pulse current heating technology is used to join TiB2-Ni cermets with Ti6A14V at different temperatures (1023K, 1073K and 1123K) with 7MPa pressure and Cu foil and Ni foil are used as joining interlayer. Joint points ...
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Pulse current heating technology is used to join TiB2-Ni cermets with Ti6A14V at different temperatures (1023K, 1073K and 1123K) with 7MPa pressure and Cu foil and Ni foil are used as joining interlayer. Joint points increase with welding temperature. The microstructure of joints is observed through SEM images and micrographs. The diffusion coefficient (D0) of Cu at the Cu/TiB2 interface is calculated by the EPMA patterns. The diffusion principle of pulse current heating and influences of electric field and current on atom diffusion are studied.
Using a reticulated polyurethane sponge with interconnected pores as primal framework and immersing into TiB2 slurry consisting of Ni and Mo as sintering additives, a porous TiB2 ceramics with high porosity and interc...
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Using a reticulated polyurethane sponge with interconnected pores as primal framework and immersing into TiB2 slurry consisting of Ni and Mo as sintering additives, a porous TiB2 ceramics with high porosity and interconnected pores was prepared by immersing and high temperature sintering process. The rheology of TiB2slurry which used silica sol as a binder was studied. The optimum condition of the slurry suitable for impregnating the polyurethane sponge was obtained. The flexural strength of the porous reticulated TiB2 ceramics can reach 1 MPa.
In this paper, silicon nitride (Si3N4) ceramics by aligning α-Si3N4 whiskers were prepared via tape casting, hot-press sintering technique using Y2O3 and MgO as sintering additives. Aligned α-Si3N4 whiskers were rea...
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In this paper, silicon nitride (Si3N4) ceramics by aligning α-Si3N4 whiskers were prepared via tape casting, hot-press sintering technique using Y2O3 and MgO as sintering additives. Aligned α-Si3N4 whiskers were realized by modifying the tape casting technique. After tape casting, Si3N4 tape with good flexibility and uniform pores can be obtained. Microstructures of the tape, green body and sintered sample were observed by SEM images. The results show α-Si3N4 whiskers in Si3N4 tape and green body were aligned preferentially along the tape casting direction. Si3N4 ceramics with aligned elongated grains are developed by hot-press sintering technique based on the reaction between Si3N4 and the sintering additives which lead to the liquid phase.
A new kind of functionally graded materials (FGM) with density gradient has come to show great potentials as flier-plates for creating quasi-isotropic compression waves. In order to meet the demand of lower density in...
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A new kind of functionally graded materials (FGM) with density gradient has come to show great potentials as flier-plates for creating quasi-isotropic compression waves. In order to meet the demand of lower density in the front face and wider density range for such flier-plate, Mg with a density of 1.74g/cm3 and W of 19.3g/cm3 are selected to make Mg-W system density graded materials, Mg-W alloys with various mass fractions of Mg and W were sintered by spark plasma sintering (SPS) technique at low temperatures, and the processing of densification is mainly investigated. It is found that, up to 92wt%W, the Mg-W alloys can be fully densified at 873K due to the conglutination of Mg particles. The Mg-W alloys still exist as a mechanical mixture of Mg and W. Finally, the Mg-W density graded materials with a density change from 1.74g/cm3 to 10.55g/cm3 have been successfully prepared.
In the present study, BaTi2O5 thin films were epitaxially grown on MgO (100) substrate by pulsed laser deposition, and the microstructure of the films was investigated. The b-axis oriented BaTi 2O5 thin film was obtai...
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ISBN:
(纸本)9788880800842
In the present study, BaTi2O5 thin films were epitaxially grown on MgO (100) substrate by pulsed laser deposition, and the microstructure of the films was investigated. The b-axis oriented BaTi 2O5 thin film was obtained at the optimum substrate temperature (Tsub = 973 K) and oxygen partial pressure (PO2 = 12.5 Pa). The as-deposited film was epitaxially grown on MgO (100), exhibiting a dense and rectangularly crossed granular texture. The epitaxial relationship between the film and substrate was BaTi2O5 (020) [100] // MgO (100) [001] and BaTi2O5 (020) [100] // MgO (100) [010].
A material in the system W/W-Cu/Cu with a density gradient, which has an important application in dynamic high pressure physics, was prepared by one-step hot-press sintering. W-Cu composite interlayers were produced f...
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ISBN:
(纸本)9788880800842
A material in the system W/W-Cu/Cu with a density gradient, which has an important application in dynamic high pressure physics, was prepared by one-step hot-press sintering. W-Cu composite interlayers were produced from W and Cu powders with Zn (2wt%) as the sintering aid. With increasing the sintering temperature, the relative density of W-Cu composites increased, reaching a higher value (>96%) at 850°C. Then by inserting three W-Cu composite interlayers between the tungsten and copper alloy plates followed by one-step hot-press at 850°C-20MPa-60min, a wholly dense W/W-Cu/Cu system functionally graded material was obtained, which had a large density range from 8.9 to 17.25g/cm3.
α-Al2O3 nanopowders were prepared by a novel synthesis process, using the nanosized α-Al2O3 obtained from pyrolyzing ammonium aluminum carbonate hydroxide as seeds and the self-dispersed nanosized AlOOH crystal powd...
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α-Al2O3 nanopowders were prepared by a novel synthesis process, using the nanosized α-Al2O3 obtained from pyrolyzing ammonium aluminum carbonate hydroxide as seeds and the self-dispersed nanosized AlOOH crystal powders as precursors. Based on their good self-dispersion in water, the α-Al2O3 seeds were dispersed evenly into the AlOOH sol by the new homodispersion mixing technique. This process enables the conversion of AlOOH to alumina at 190°C (hydrothermal temperature), in which the alumina is calcined to nanosized alpha-alumina having an average length to diameter ratio of 60nm:15nm at 930°C. In the synthesis reaction for transforming the AlOOH to alumina, the effect of superfine pulverization and self-dispersion of the precursors was studied.
In this study, K3Li2-xNb5+xO 15+2x (KLN) thin films were prepared by laser-ablated a sintered ceramic target. For an optimum deposition condition, in-situ post annealing method was employed on as-deposited films. XRD ...
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In this study, K3Li2-xNb5+xO 15+2x (KLN) thin films were prepared by laser-ablated a sintered ceramic target. For an optimum deposition condition, in-situ post annealing method was employed on as-deposited films. XRD measurements showed that KLN films with (310) preferred orientation were obtained on fused quartz substrate. Surface morphology studies indicated mat in-situ post annealing could improve the surface quality of KLN thin films. The average transmittance of as-deposited and annealed films in the visible range was nearly 80% to 90%.
The high intensity of thermal stress was generated during fabrication of 6063 aluminum/60SiC‐35Al‐5Si double‐layer material. In order to decrease the thermal stress, graded materials of Al/60SiC‐35Al‐5Si was fabr...
The high intensity of thermal stress was generated during fabrication of 6063 aluminum/60SiC‐35Al‐5Si double‐layer material. In order to decrease the thermal stress, graded materials of Al/60SiC‐35Al‐5Si was fabricated by spark plasma sintering. The CTE in the graded layer was controlled by SiC fraction and particle sizes. The calculation results indicate that the net stress of more than 800 MPa was generated in the double‐layer materials, but it decreased to 170 MPa or less in the graded materials. So the stability can be guaranteed in the graded composites. The graded layers also have the potential for high thermal conductivity, more than 180W/Mk for every layer, which satisfies the application.
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