The concept and method of analysis of photonic crystals and band gaps are introduced into InP-film network structure, which is treated theoretically as photonic crystals. We investigate different aspects of the absolu...
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The concept and method of analysis of photonic crystals and band gaps are introduced into InP-film network structure, which is treated theoretically as photonic crystals. We investigate different aspects of the absolute photonic band gap (PBG) formation for 2D photonic crystal (PC) consisting of air bars drilled into InP films. The formation of PBG is exhibited and confirmed by a calculation of the transfer matrix method (TMM). We find that for InP based networks for a lattice constant of 0.45 a (a=250 nm) two PBGs exist, which ranges are from 530 to 700 nm and from 800 to 940 nm at visible and near-infrared frequency.
This paper aimed at the high added value use of a deoiled asphaltene. Monodispersed highly graphitized graphitic spheres (GSs) with high thermal stability were synthesized by vacuum thermal processing followed chemica...
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This paper aimed at the high added value use of a deoiled asphaltene. Monodispersed highly graphitized graphitic spheres (GSs) with high thermal stability were synthesized by vacuum thermal processing followed chemical vapor deposition (CVD). The carbon microbeds and the synthesized GSs were compared by means of SEM, HRTEM, XRD and TGA. Vacuum thermal processed GSs are of high degree of graphitization and good thermal stability. The disordered structure of carbon microbeds were thermodynamically propelled to transit to the graphitic structure, forming the GSs.
A nanostructured surface layer was fabricated on a magnesium alloy AZ31B by using a surface mechanical attrition treatment (SMAT) technique. SMAT induced structural changes along the depth of the treated sample surfac...
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A nanostructured surface layer was fabricated on a magnesium alloy AZ31B by using a surface mechanical attrition treatment (SMAT) technique. SMAT induced structural changes along the depth of the treated sample surface layer were characterized by means of X-ray diffraction (XRD), transmission electron microscope (TEM). Experimental results show that the nanostructured surface layer is formed after SMAT and the average grain size increases from 50 nm in the surface layer to 200nm at the depth of 40 μm. The mechanism for nanostructure formation is the co-actions of the deformation twinning and dynamic recrystallization. The hardness of nanostructured surface layer is enhanced significantly after SMAT compared with that of the initial sample.
The technical processes of preparing onion-like fullerenes (OLFs) with different current densities by arc-discharge in water were explored. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and high-resoluti...
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The technical processes of preparing onion-like fullerenes (OLFs) with different current densities by arc-discharge in water were explored. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) were used to characterize the morphologies and microstructures of the OLFs. The results indicated that the OLFs had an hollowness at the centre with diameter about 25 nm. The influence of current density on yield, productivity and degree of graphitization of the OLFs were studied. The yield and productivity of OLFs rose obviously with the increasing of current density in the range of 20-50A.
A nanostructurd surface layer was fabricated on an Al-Zn-Mg alloy using a High Energy Shot Peening (HESP) technique. HESP induced structure along the depth of the treated sample surface layer was characterized by mean...
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A nanostructurd surface layer was fabricated on an Al-Zn-Mg alloy using a High Energy Shot Peening (HESP) technique. HESP induced structure along the depth of the treated sample surface layer was characterized by means of X-ray diffraction, optical electron microscope and transmission electron microscope, and the thermal stability of the surface nanocrystallites was examined. Experimental results show that equiaxed nanocrystallites with random crystallographic orientations were obtained in the surface layer of Al-Zn-Mg alloy samples by means of HESP. In the process of severe plastic deformation, grains were subdivided during straining on a smaller and smaller scale. Dynamic recrystallization may be the final cause of the nanocrystallites formation. The high strains with a high strain rate are necessary for the formation of nanocrystallites during plastic deformation of metals. After vacuum annealed at 250°C for lh, the grain size of the surface crystals grew to about 300 nm, indicating satisfying thermal stability.
Rare-earth oxide graphite intercalation compounds （CeO-GICs） were prepared using graphite and CeO as raw materials by vacuum *** stage-5 GICs was formed after heat treatment at 800℃,and it was examined and characte...
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Rare-earth oxide graphite intercalation compounds （CeO-GICs） were prepared using graphite and CeO as raw materials by vacuum *** stage-5 GICs was formed after heat treatment at 800℃,and it was examined and characterized by X-ray diffraction （XRD）.The XRD analysis of intercalation compounds indicated that a number of non- carbon reactant （atom,molecule,ion or groups） could intercalate the layers of graphite with reticulated layer structure *** the layered structure of graphite changed and new physical and chemical properties were ob- tained.X-ray photoelectron spectroscopy （XPS） suggested that the compound intercalated into graphite should contain Ce compounds.
Magnesium alloys have been considered as one of most potential advanced structural materials because of their low density,high specific strength and specific *** have found their wide application in air-plane and auto...
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Magnesium alloys have been considered as one of most potential advanced structural materials because of their low density,high specific strength and specific *** have found their wide application in air-plane and automobile industries[1].However,the poor ductility of magnesium makes it difficult to form because of its hcp *** magnesium alloys normally
Recently,zeolite became very attractive for synthesizing of functional materials in nanometer dimension,such as molecular *** provided a variety of uniform nano channels and such well-defined nanospaces were utilized ...
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Recently,zeolite became very attractive for synthesizing of functional materials in nanometer dimension,such as molecular *** provided a variety of uniform nano channels and such well-defined nanospaces were utilized for synthesizing unique nano materials as *** the present paper,we reported a novel method to prepare homogeneous carbon nano particles by
Schiff base 1, 2-cyclohexyldiamino-N, N'-bis (2-hydroxy-3-methoxybenzaldehyde) (1) and its zinc complex (2) were synthesized. The structure of the ligand and its compound (2) was characterized by IR and elemental ...
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Schiff base 1, 2-cyclohexyldiamino-N, N'-bis (2-hydroxy-3-methoxybenzaldehyde) (1) and its zinc complex (2) were synthesized. The structure of the ligand and its compound (2) was characterized by IR and elemental analysis techniques. The UV-vis absorption and photoluminescence spectra of the compound (2) indicate that it is a blue emitter under UV radiation while the effective energy-transfer from the ligand to the central Zn2+ ion occurs in the complex. The electrochemical band gap is approximatively consistent with optical band gap estimated by UV-vis absorption spectral edge. The results indicated the complex (2) could emit intensive blue fluorescence with peak wavelength at 460 nm and bandwidth of 72.2 nm under UV excitation at 365 nm. The complex (2) of bright blue photoluminescence might be applied as luminescent in organic electroluminescence devices (OLEDs).
Cr2O3-graphite intercalation compounds (GICs) were prepared using graphite and CrO3 as raw materials by vacuum heat-treatment. The stage 5 GICs was formed after heat treatment at 1400°C, and it was examined and c...
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Cr2O3-graphite intercalation compounds (GICs) were prepared using graphite and CrO3 as raw materials by vacuum heat-treatment. The stage 5 GICs was formed after heat treatment at 1400°C, and it was examined and characterized by X-ray diffraction (XRD). The XRD analysis of intercalation compounds indicated that a number of non-carbon reactant (atom, molecule, ion or groups) could intercalate the layers of graphite with reticulated layer structure physically. Consequently the layered structure of graphite changed and thus new physical and chemical properties were obtained. X-ray photoelectron spectroscopy (XPS) suggested that the compound intercalated into graphite should contain CrIII compound.
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