Based on the boundary conditions of the running parameters and test data of 125 MW boiler drum, the transient thermal stress, mechanical stress and whole stresses of the boiler drum under four different working condit...
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Based on the boundary conditions of the running parameters and test data of 125 MW boiler drum, the transient thermal stress, mechanical stress and whole stresses of the boiler drum under four different working conditions were computed by finite element methods under 3-dimension model. The relationship among the three kinds of stresses was discussed as well as the spot of maximum stress and its varying tendency with the time was obtained.
X-ray diffraction (XRD) analysis on different polished surfaces normal to the hot pressing direction reveals that the phase compositions of the polished surfaces from the outside to the inside are pure TiC, Ti_3AlC_2+...
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X-ray diffraction (XRD) analysis on different polished surfaces normal to the hot pressing direction reveals that the phase compositions of the polished surfaces from the outside to the inside are pure TiC, Ti_3AlC_2+TiC, pure Ti_3AlC_2 and Ti_2AlC+Ti_3AlC_2, no matter elemental powder or TiC is used as raw materials. It is found that ternary-layered carbide Ti_2AlC samples synthesized at 1500 ℃ by hot-pressing sintering are inhomogeneous and have a gradient *** probe X-ray micro-analysis (EPMA) indicates that the Al content along the hot pressing axis is parabolic, it is the highest in the center and the lowest at the both ends, while the Ti content is constant along the axis. The experimental result reveals that the evaporation of Al in samples in an open system during hot pressing sintering results in a gradient structure.
This paper studied the thermal stresses of ceramicl metal gradient thermal barrier coating which combines the conceptions of ceramic thermal barrier coating （TBC） and functionally gradient material （FGM）. Thermal ...
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This paper studied the thermal stresses of ceramicl metal gradient thermal barrier coating which combines the conceptions of ceramic thermal barrier coating （TBC） and functionally gradient material （FGM）. Thermal stresses and residual thermal stresses were calculated by an ANSYS finite element analysis software. Negative thermal expansion coefficient method was proposed and element birth and death method was applied to analyze the residual thermal stresses which have non-uniform initial temperature field. The numerical results show a good agreement with the analytical results and the experimental results.
A series of bulk polycrystalline La1-xLixMnO3 samples with x ranging from 0.1 to 0.5 was prepared by sol-gel method,X-ray diffraction patterns show that the crystal structures are single rhombohedral perorskite for th...
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A series of bulk polycrystalline La1-xLixMnO3 samples with x ranging from 0.1 to 0.5 was prepared by sol-gel method,X-ray diffraction patterns show that the crystal structures are single rhombohedral perorskite for the x≤0.3 sample and the impurity appears when x〉*** the same synthesized conditions,the higher Li content samples display a higher content of liquid phase content and larger mean grain sizes,which leads to the increases of the effect of the grain *** experimental results show that the change of the ferromagnetic transition temperature and the resistivity can attribute to the effect of the grain boundary and the connectivity of the inter grains as well as the ratio of Mn^3＋ to Mn^4＋.
作者：
王友法Biomedical Materials and Engineering Research Center
Wuhan University of TechnologyWuhan 430070ChinaState Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China
Inorganic nanoparticles were used to treat cancer cells us well as normal cells. Ca9Sr（ PO4）6（OH）2 nanopartides were prepared through homogeneous precipitation method. Strontium hydroxide, calcium hydroxide solat...
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Inorganic nanoparticles were used to treat cancer cells us well as normal cells. Ca9Sr（ PO4）6（OH）2 nanopartides were prepared through homogeneous precipitation method. Strontium hydroxide, calcium hydroxide solation and monocalcium phosphate were used as initial materials. The strontium-doped hydroxyapatite nanoparticles were characterized by XRD, PCS and AFM. The nanoparticles were applied to interact with human bepatocellular carcinoma cells Bel-7402 and nornud liver cells L-02. Experimental results revealed that nano strontium-strontium apatiw has different bioeffects on proliferation of these two kinds of cells.
The HAP nanoparticles were synthesized with a chemical co-precipitation method. It was monodispersed in needle shape, Its average diameter was 30 nm and length was 70 nm. Human liver cancer cells and normal hepatic ce...
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The HAP nanoparticles were synthesized with a chemical co-precipitation method. It was monodispersed in needle shape, Its average diameter was 30 nm and length was 70 nm. Human liver cancer cells and normal hepatic cells were treated by hydroxyapatite nanopartides. SR-XRF analysis was used to detect the content variation of calcium and phosphor elements in cancer cells when the cells were treated by hydroxyapatite nanoparticles. It was introduced to reveal the anti-cancer mechanism of HAP nanoparticles. Experiments verified that the contents of calcium and phosphor elements in hepatocelltdar carcinoma had been obviously increased after the cells were treated by hydroxyapatite nanoparticles. And the contents increased with hydroxyapatite concentration and treatment time increasing. The Ca/P molar ratio in treated cell was different from both that in hydroxyapatite and that in untreated cancer cell. Apatite nanoparticles evidently altered the calcium and phosphor environmeats in treated hepatocellalar carcinoma cells. That finally halted the proliferation of carcinoma cells.
The Ti2AlC-Ti3AlC2-Ti3SiC 2 composite was fabricated in Ti-Al-Si-C quaternary system by spark plasma sintering (SPS) method from elemental powders. IN the SPS process, the gas in the chamber is discharged out at a con...
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The Ti2AlC-Ti3AlC2-Ti3SiC 2 composite was fabricated in Ti-Al-Si-C quaternary system by spark plasma sintering (SPS) method from elemental powders. IN the SPS process, the gas in the chamber is discharged out at a constant rate. It was observed that pressure peaks appeared in both samples sintered at 1200 and 1300 °C. It was found that for the sample sintered at 1300 °C, pressure peak was more pronounced than that of sample sintered at 1200 °c, which indicates the evaporation of Al or Si is more serious in sample sintered at 1300 °C, leading to the formation of TiC and the disapperance of Ti2AlC.
With the preparation of organic-inorganic layered perovskite-type compounds (C4H9NH3)2MCl4 (M = Mn, Cu) in solutions, X-ray diffraction (XRD), scanning electron microscopy (SEM),thermal gravimetry (TG) and differentia...
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Polycrystalline samples of Sr4Nd2Ti 4Ta6O30 (SNTT) and Sr4Sm 2Ti4Ta6O30 (SSTT) were prepared using high temperature solid state reaction techniques. SNTT and SSTT showed room temperature dielectric constant of around ...
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Polycrystalline samples of Sr4Nd2Ti 4Ta6O30 (SNTT) and Sr4Sm 2Ti4Ta6O30 (SSTT) were prepared using high temperature solid state reaction techniques. SNTT and SSTT showed room temperature dielectric constant of around 225 and 220 at 1 MHz. SSTT belongs to ferroelectric phase of tungsten-bronze (TB) structure and underwent diffuse type of ferroelectric-paraelectric phase transition around 30°C. Low temperature dielectric constant observed in the ceramic sample indicates that it may have attractive benefits in electrooptic and infrared pyroelectric detector applications when grown in buck single crystal or thin film form.
In order to compare the spark plasma sintedng （SPS） process plus hot isostatic press （HIP） with vacuum sintedng plus HIP, an investigation was carried out on the topography, microstructure and gain size distributi...
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In order to compare the spark plasma sintedng （SPS） process plus hot isostatic press （HIP） with vacuum sintedng plus HIP, an investigation was carried out on the topography, microstructure and gain size distribution of nanocrystalline WC-10Co composite powder and the sintered specimens prepared by SPS plus HIP and by vacuum sintering plus HIP by means of atomic force microscopy （AFM）. The mechanical properties of the sintered specimens were also investigated. It is very easy to find cobalt lakes in the specimen prepared by vacuum sintering plus HIP process. But the microstructure of the specimen prepared by SPS plus HIP is more homogeneous, and the grain size is smaller than that prepared by vacuum sintering plus HIP. The WC-10Co ultrafine cemented carbide consolidated by SPS plus HIP can reach a relative density of 99.4%, and the transverse rupture strength （TRS） is higher than 3540 MPa, the Rockwell A hardness （HRA） is higher than 92.8, the average grain size is smaller than 300 nm, and the WC-10Co ultrafine cemented carbide with excellent properties is achieved. The specimen prepared by SPS with HIP has better properties and microstructure than that prepared by vacuum sintering with HIP.
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