Hollow and porous nanostructures have attracted a great deal of attention because of their widespread potential applications,and nanostructures with tunable size are desirable to optimize their ***,simple and high yie...
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Hollow and porous nanostructures have attracted a great deal of attention because of their widespread potential applications,and nanostructures with tunable size are desirable to optimize their ***,simple and high yield methods for preparation of nanostructures with tunable sizes have been regarded as pursuing ***,we report a novel simple method for large scale synthesis of porous ZnO hollow structures with tunable diameters and shell *** novel synthesis strategy involves oxidizing Zn spheres and polyhedrons in solid state to form a thin ZnO layer on the surface under low temperature,followed by removal of the Zn cores upon ***,not only can the diameter and shell thickness be respectively tuned,but also the shell thickness can be also easily controlled because of its slow oxidation rate in a solid-phase diffusion process under low *** is obvious that this novel simple method involved here can readily be extended to other metal oxide systems.
TaVO,which had a property of negative thermal expansion was prepared by solid-state *** average volume thermal expansion coefficients were 5.16×10/℃below room temperature（-150-20℃） and -1.22×10～5/℃abov...
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TaVO,which had a property of negative thermal expansion was prepared by solid-state *** average volume thermal expansion coefficients were 5.16×10/℃below room temperature（-150-20℃） and -1.22×10～5/℃above room temperature（20-800℃）.The structure of TaVO was investigated by neutron powder *** refinements were conducted on neutron data collected at -100,20 and 400℃revealed that there was a phase transition at about 15℃.The space group is P12/ml below this transition and Pnma above this *** negative thermal expansion of TaVO might be a consequence of rocking motions of the corner-shared TaO octahedral and VO tetrahedral.
Over the past few years,the concept of strain has been of interest at different scales for GaN *** is due to the fact that the presence of strain will not only change the lattice constant and the crystallographic symm...
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Over the past few years,the concept of strain has been of interest at different scales for GaN *** is due to the fact that the presence of strain will not only change the lattice constant and the crystallographic symmetry,but also the physical properties of the *** this paper,thick GaN films on c-sapphire(α-Al2O3) substrates with a self-buffer have been deposited by low pressure metal-organic chemical vapor deposition(LPMOCVD).The lattice constant in the hexagonal structure GaN films is measured using a high resolution x-ray diffraction technique at room *** obtain accurate results,emphasis has been placed on the importance of a carefully corrected Bragg angle of the GaN film.A strategy for eliminating related error will be *** results show that the lattice constants a and c of the GaN films are almost the same as that of the bulk *** space map(RSM) observation provided useful insights into the strain state in GaN *** residual stress in the GaN films is believed to be fully *** purpose of this paper is to measure the lattice constant of epitaxial GaN *** is important to realize that controlling GaN strain(or stress) is necessary to obtain desirable physical properties.
In order to get the stable discharging state,addition of flux to high ash fusion temperature Chinese coals are considered the principal challenges to the economic use of coals in slagging *** were carried out into the...
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In order to get the stable discharging state,addition of flux to high ash fusion temperature Chinese coals are considered the principal challenges to the economic use of coals in slagging *** were carried out into the influences of magnesium oxide on melting behavior of different coal ashes with different ash fusion temperature under reducing *** the increase of MgO addition,the melting temperature of ash initially decreases sharply,then gradually reaching its minimum value at the amount of MgO around 15%in ash. However increasing again with the further addition of *** and SEM were used to examine the mineral transformation of coal ashes at high ***'s shown that MgO can reduce the fusion temperature *** it's increased the proportion of alkalescent oxides,and the other is that in high temperature mullite reacted with periclase to form cordierite,forsterite and sapphirine,they are produce a low-melting eutectic mixture which decreases the ash fusion temperate.
N-doped ZnO/Ag nanocomposites were successfully prepared by using a plasma-assisted reactive evaporation(PARE) *** lattice parameters of the prepared nanocomposite were refined,their energy band and density of states ...
N-doped ZnO/Ag nanocomposites were successfully prepared by using a plasma-assisted reactive evaporation(PARE) *** lattice parameters of the prepared nanocomposite were refined,their energy band and density of states were also calculated with density functional theory (DFT) and studied the property of photochemical *** to the doping of N,the lattice parameters of original ZnO/Ag nanocomposites were altered which is most significant in the crystal face of(001).The band gap of the doped nanocomposites was about 1.19～0.47eV lower than that of pure ZnO,indicating the increased the activity of photochemical catalysis after doping.
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