Since some transition metal diborides have the same crystal structure with TiB 2, which can react with TiB 2 to form solid solution by adequate technique. With ZrB 2 used as additive, the TiB 2-ZrB 2 solid solution wa...
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Since some transition metal diborides have the same crystal structure with TiB 2, which can react with TiB 2 to form solid solution by adequate technique. With ZrB 2 used as additive, the TiB 2-ZrB 2 solid solution was prepared by hot pressing. The effects of additive content on mechanical properties of composite were investigated. The microstructure analyzing were employed by EPMA, SEM and TEM. It is shown that TiB 2 can partly form solid solution with ZrB 2 and redound to gain uniform grains, which results in the increase of mechanical properties.
A new compound,[Co（dien）2]（dienH3）（H3O）7[P2Mo5O23]2·14H2O, has been hydrothermallly synthesized by using Na2MoO4,CoCl2, H3PO4 and dien, and structurally characterized by elemental analysis, X-ray powder dif...
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A new compound,[Co（dien）2]（dienH3）（H3O）7[P2Mo5O23]2·14H2O, has been hydrothermallly synthesized by using Na2MoO4,CoCl2, H3PO4 and dien, and structurally characterized by elemental analysis, X-ray powder diffraction analysis, SEM, IR and TG analysis. The results show that the compound is composed of a polyanion [P2Mo5O23]2^12, complex [Co（dien）2]^2＋ cation, protonated [dienH3]^3＋ , and forteen crystallization water molecule.
The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing（HSCS） pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron m...
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The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing（HSCS） pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron microscope （SEM）, Fourier transform infrared spectrophotometry （FTIR）. Ultraviolet-visible pectrophotometer was used to determine the extraction ratio of aqueous solubility polysaccharide between the raw and broken spores. The immunological function on the mice before and after the breaking of spores wan investigated. The experimental results show that after being ground, the sporoderm-broken ratio reachs 100%, the original active ingredients of ganoderma lucidum spores do not change, and the extraction ratio of aqueous solubility polysaccharide is greatly increased by 40.08%. The broken spores show much higher immunological activity comparing with original spores of Ganoderma lucidum.
The unsatisfactory conductivity and large volume variation severely handicap the application of SnO2in sodium-ion batteries（SIBs）. Herein, we design unique three-layer structured SnO2@C@TiO2hollow spheres to tackle ...
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The unsatisfactory conductivity and large volume variation severely handicap the application of SnO2in sodium-ion batteries（SIBs）. Herein, we design unique three-layer structured SnO2@C@TiO2hollow spheres to tackle the above-mentioned issues. The hollow cavity affords empty space to accommodate the volume variation of SnO2, while the C and TiO2protecting shells strengthen the structural integrity and enhances the electrical conductivity. As a result, the three-layer structured SnO2@C@TiO2hollow spheres demonstrate enhanced Na storage performances. The SnO2@C@TiO2manifests a reversible capacity two times to that of pristine SnO2hollow spheres. In addition, Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO2@C@TiO2hollow spheres. This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials.
WC-10Co nanocrystalline composite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing （HIP）. Influences of carbo...
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WC-10Co nanocrystalline composite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing （HIP）. Influences of carbon content on properties and microstructure of ultrafine WC-10Co cemented carbide were investigated. The results show that the relative density of the ultrafine WC-10Co cemented carbides can reach 99.72%, and the transverse rupture strength （TRS） was higher than 3 890 MPa, Rockwell A hardness （HRA） was higher than 92.5, the average grain size was less than 460 nm, when carbon content in nanocrystalline composite powder was 5.54wt% and the ball-milled time was 48 hours, ultrafine WC-10Co cemented carbide with excellent properties and homogeneous microstructure was obtained.
A ternary-layered carbide Ti2AlC material could be synthesized by spark plasma sintering（SPS） technology using elemental powder mixture of Ti, Al and active carbon. By means of XRD and SEM, phases were identified an...
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A ternary-layered carbide Ti2AlC material could be synthesized by spark plasma sintering（SPS） technology using elemental powder mixture of Ti, Al and active carbon. By means of XRD and SEM, phases were identified and microscopically evaluated. The experimental results show that the main phase in the product was fully crystallized Ti2AlC with small particle size when sintered at 1200℃. The synthesis temperature of SPS was 200-400℃ lower than that of hot pressing （HP） or hot isostatic pressing （HIP）. Through thermodynamics calculations, the mechanism of Ti2AlC was studied by calculating changes of Gibbs free energy of reactions.
ZnO sub-millimeter crystals were synthesized by microwave heating from ZnO powders without any catalyst or transport agent. Zinc oxide raw materials were evaporated from the high-temperature zone in an enclosure and c...
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ZnO sub-millimeter crystals were synthesized by microwave heating from ZnO powders without any catalyst or transport agent. Zinc oxide raw materials were evaporated from the high-temperature zone in an enclosure and crystals were grown on the self-source substrate. The thermodynamics analysis method was used to estimate the partial pressure of gases in the chamber, which shows that the pressure of ZnO could be neglected entirely in the range of experiment temperature. The kinetics analysis was employed to estimate the growth rate in different conditions, which shows a remarkable temperature gradient and a high system temperature would enhance the growth rate. Optics photos reveal that these products are hexagon crystals with 0.2-0.3 mm in diameter and 0.5-1 mm in length. A vapor-solid mechanism is proposed to explain the growth process of ZnO crystals. The temperature distribution in microwave oven is mainly determined by properties of electric field and it is different from that of a conventional method.
MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxid...
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MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxide films on Si *** effect of Tsub on the preferred orientation,crystallinity and surface morphology of the films was *** films in single-phase were obtained at 473-973 *** increasing Tsub,the preferred orientation of the films changed from （200） to （111）.The crystallinity and surface morphology was different too,depending on *** Tsub=673 K,the MgO film became uniform and smooth,exhibiting high crystallinity and a dense texture.
Epitaxial （0001）-oriented Zn1-xCoxO （x= 0.01, 0.05 and 0.1） thin films were grown on c-sapphire substrates by pulsed laser deposition. The XRD analysis, optical transmittance and XPS measurements revealed that the...
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Epitaxial （0001）-oriented Zn1-xCoxO （x= 0.01, 0.05 and 0.1） thin films were grown on c-sapphire substrates by pulsed laser deposition. The XRD analysis, optical transmittance and XPS measurements revealed that the Co2＋ substituted Zn2＋ ions were incorporated into the lattice of ZnO in Zn1-xCoxO thin films. The electrical properties measurements revealed that the Co concentration had a non- monotonic influence on the electrical properties of the Zn1-xCoxO thin films due to the defects resulted from imperfections induced by Co substitution. The resistivity remarkably increased and the carrier concentration remarkably decreased in Zn1-x CoxO thin films after oxygen annealing at 600 ℃ under 15 Pa O2 pressure for 60 mins. Room-temperature ferromagnetic was observed and the ferromagnetic Co amount was smaller than the nominal Co concentration for Zn1-xCoxO samples before oxygen annealing. After oxygen annealing, the Zn1-x CoxO thin films exhibited paramagnetic behavior. It is suggested that the room-temperature ferromagnetic ofZn1-x CoxO thin films may attribute to defects or carriers induced mechanism.
Electrical conductivity and seebeck coefficient at different temperatures,and thermal conductivity at room temperature for various doped polyaniline (PAn) samples were measured,and the thermoelectric figure of merit Z...
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Electrical conductivity and seebeck coefficient at different temperatures,and thermal conductivity at room temperature for various doped polyaniline (PAn) samples were measured,and the thermoelectric figure of merit ZT was *** effects of preparation methods and temperature on thermoelectric properties were *** results show that the electrical conductivity and the seebeck coefficient of PAn are strongly dependent on the preparation conditions and *** electrical conductivity becomes larger and the seebeck coefficient becomes smaller as PAn molecular weight *** by organic acid and HCl results in an increase in both electrical conductivity and Seebeck coefficient of PAn,and therefore ZT *** electrical conductivity increases and the seebeck coefficient decreases as the temperature increases when TT *** thermal conductivity is lower,and insensitive to the sample preparation conditions.
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