Patterned ZnO nanorods have been first grown on patterned silicon nanocrystallite (SiNC) films that were fabricated on (100) orientation p-type boron-doped silicon wafer by hydrogen ion implantation technique and the ...
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Patterned ZnO nanorods have been first grown on patterned silicon nanocrystallite (SiNC) films that were fabricated on (100) orientation p-type boron-doped silicon wafer by hydrogen ion implantation technique and the anodic etching method, and their field emission properties were obtained. Field emission measurements demonstrated that the synthesized ZnO nanorods have excellent field emission properties, namely low turn-on field, low threshold field, and high emission spot density. The patterned ZnO nanorods have great potential in the application of flat panel displays.
In order to unclose the dynamics of SPS densification, a special sintering sample (Cu/Ti wires compact) was designed. Characters of the shrinkage rates during sintering process and microstructures of products fabricat...
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In order to unclose the dynamics of SPS densification, a special sintering sample (Cu/Ti wires compact) was designed. Characters of the shrinkage rates during sintering process and microstructures of products fabricated by the spark plasma sintering(SPS) and hot-press sintering were investigated. The experimental results reveal that a higher temperature field is formed at the connected area and conductive net of the compact. These high-temperature parts deformed more easily than other parts, which is believed to be the main cause of SPS fast densification, according to a hard-core and soft-hell material model.
Polymer-protected monodisperse nickel nanoparticles were synthesized by a modified polyol reduction method in the presence of poly（N-vinyl-2-Pyrrolidone）.These nanoparticles were characterized by transmission electr...
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Polymer-protected monodisperse nickel nanoparticles were synthesized by a modified polyol reduction method in the presence of poly（N-vinyl-2-Pyrrolidone）.These nanoparticles were characterized by transmission electron microscopy（TEM）,X-ray diffraction（XRD）,selected area electron diffraction（SAED）,as well as vibrating sample magnetometer（VSM）.The experimental results show that the addition of PVP and the concentration of NaOh have strong influences on the *** and uniformity of *** the presence of PVP and NaoH with low *** nickel nanoparticles with average diameters about 42 nm were obtained and characterized to the pure nickel crystalline with foc *** structures such as *** strings resulted from magnetic interactions between particles were *** chemical interaction between the PVP and nickel nanoparticles was found by *** saturation magnetization（Ms）.remanent magnetization（Mr）and coercivity（Hc）of these nickel nanoparticles are lower than those of bulk nickel.
ZrB2 ceramics were prepared by self-propagating high-temperature synthesis（SHS） and were sintered by hot pressing（HP）.The effects of the granularities and doses of raw materials in Zr-B2O3-Mgon SHS process and pro...
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ZrB2 ceramics were prepared by self-propagating high-temperature synthesis（SHS） and were sintered by hot pressing（HP）.The effects of the granularities and doses of raw materials in Zr-B2O3-Mgon SHS process and product were *** and combustion temperature curves prove that the ideal SHS reactants of Zr-B2O3-Mg are 50μm Zr powder,75μm B2O3 powder and 400μm Mg powder with 45% *** particle sizes of SHS product,acid-leached product,sintered product are 2-5μm,0.5-2μm,2-10μm *** analysis indicates that the acid-leached product consists of ZrB2（94.59%）,ZrO2（3.87%）,and H3BO3（1.54%）,The sintered product has a relative density of 95.4%.
When boiler runs under certain pressure and temperature, the disfigurement and crack will propagate, resulting in failure of the boiler drum. According to the Assess criterion of Pressure Container's Disfigurement...
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When boiler runs under certain pressure and temperature, the disfigurement and crack will propagate, resulting in failure of the boiler drum. According to the Assess criterion of Pressure Container's Disfigurement, the maximal stress value in the dangerous area for 125MW boiler drum and its change within certain time frame under different working conditions are found out by means of finite element method. The allowable length of crack is calculated with COD mode and the yearly crack-propagating value is predicted and analyzed.
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.
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＋.
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.
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.
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