A review of our experience in range of electron spectroscopy of the physical vapor-phase deposition and growth of single- and multilayer nanostructures with atomic scale interfaces is presented. The foundation of an i...A review of our experience in range of electron spectroscopy of the physical vapor-phase deposition and growth of single- and multilayer nanostructures with atomic scale interfaces is presented. The foundation of an innovative methodology for the combined AES-EELS analysis of layered nanostructures is developed. The methodology includes: 1) determination of the composition, thickness, and the mechanism of phase transitions in nanocoatings under the probing depth most appropriated for the range of film thickness 1 - 10 ML;2) quantitative iteration Auger-analysis of the composition, thickness and growth mechanism of nanocoating;3) structural and phase analysis of nanocoatings with use of the analysis of position, shape and energy of the plasmon EELS peak and with subtracting the contribution from the substrate;4) analysis of phase transitions with use of the shift of the plasmon Auger-satellite and 5) non-destructive profiling of the composition of nanocoatings over depth with use of a dependence of the intensity and energy of EELS peaks on the value of the primary electron energy.展开更多
We investigate a modified surface wave splitter with a double-layer structure, which consists of symmetrical metallic grating and an asymmetrical dielectric, using the finite-difference time-domain （FDTD） simulation...We investigate a modified surface wave splitter with a double-layer structure, which consists of symmetrical metallic grating and an asymmetrical dielectric, using the finite-difference time-domain （FDTD） simulation method. The metal/dielectric interface structure at this two-side aperture can support bound waves of different wavelengths, thus guiding waves in opposite directions. The covered dielectric films play an important role in the enhancement and confinement of the diffraction wave by the waveguide modes. The simulation result shows that the optical intensities of the guided surface wave at wavelengths of 760-nm and 1000-nm are about 100 times and 4-5 times those of the weaker side, respectively, which means that the surface wave is split by the proposed device.展开更多
In the present work,hierarchical nanostructured titanium dioxide(TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr(TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased elect...In the present work,hierarchical nanostructured titanium dioxide(TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr(TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased electrolyte containing 0.5wt% NH4F.The nanostructured TiO2 films exhibited three distinct types depending on the anodization time:top irregular nanopores(INP)/beneath regular nanopores(RNP),top INP/middle regular nanotubes(RNT)/bottom RNP and top RNT with underlying RNP.The evolution of the nanostructured TiO2 films with anodization time demonstrated that self-organizing nanopores formed at the very beginning and individual nanotubes originated from underlying nanopore dissolution.Furthermore,a modified two-stage self-organizing mechanism was introduced to illustrate the growth of the nanostructured TiO2 films.Compared with TLM titanium alloy matrix,the TiO2 films with special nano-structure hold better hydrophilicity and higher specific surface area,which lays the foundation for their biomedical applications.展开更多
A novel layered hexagonal boron nitride/titanium dioxide(h-BN/TiO2) composite photocatalyst has been constructed by anchoring TiO2 nanoflakes on the surface of hBN flakes via a solvothermal method. The morphology and ...A novel layered hexagonal boron nitride/titanium dioxide(h-BN/TiO2) composite photocatalyst has been constructed by anchoring TiO2 nanoflakes on the surface of hBN flakes via a solvothermal method. The morphology and dispersion of TiO2 can be tuned by controlling the amount of flake h-BN. Benefiting from the unique hetero-structure, the photocatalytic performance of the obtained composite toward rhodamine B(Rh B) degradation is greatly enhanced, among which 12 wt% h-BN/TiO2 composites show 3.5 and 6.9 times higher degradation rate than the synthesized TiO2 and commercial TiO2(P25), respectively, and an excellent cycling stability has also been obtained. Moreover, the first-principles calculation reveals the synergetic catalytic effect between TiO2 and h-BN flake, which is found to be responsible for the significantly enhanced photocatalytic performance of h-BN/TiO2 composites.展开更多
Using fast multiple rotation rolling(FMRR),a nanostructure layer was fabricated on the surface of Ti6Al4V alloy.The microstructure of the surface layer was investigated using optical microscopy,transmission electron m...Using fast multiple rotation rolling(FMRR),a nanostructure layer was fabricated on the surface of Ti6Al4V alloy.The microstructure of the surface layer was investigated using optical microscopy,transmission electron microscopy,scanning electron microscopy,and X-ray diffraction.The results indicated that a nanostructured layer,with an average grain size of 72—83 nm,was obtained in the top surface layer,when the FMRR duration was 15 min.And the average grain size further reduced to 24—37 nm when the treatment duration increased to 45 min.High density dislocations,twins,and stacking faults were observed in the top surface layer.The microhardness of FMRR specimen,compared with original specimen,was significantly increased.A uniform,continuous and thicker compound layer was obtained in the top surface of FMRR sample,and the diffusion speed of N atom in the top surface layer was accelerated.FMRR treatment provides corrosion improvement.展开更多
In the present study,we calculated the elastic,mechanical,and thermo-physical properties of Zirconium Nitride(ZrN)/Magnesium Oxide(MgO)(001)nanostructures in the temperature range of 50∼300 K using higher-order elast...In the present study,we calculated the elastic,mechanical,and thermo-physical properties of Zirconium Nitride(ZrN)/Magnesium Oxide(MgO)(001)nanostructures in the temperature range of 50∼300 K using higher-order elastic constants.With two fundamental factors,nearest-neighbor distance and hardness parameter,in this tem-perature range,the second-and third-order elastic constants(SOECs and TOECs)are estimated using the Coulomb&Born-Mayer potential.The computed values of SOECs have been used to calculate Young’s modulus,thermal conductivity,Zener anisotropy,bulk modulus,thermal energy density,shear modulus,and Poisson’s ratio to as-sess the thermal and mechanical properties of the ZrN/MgO(001)nanostructured layer.Additionally,SOECs are used to calculate the wave velocities for shear as well as longitudinal modes of propagation along crystalline orientations<100>,<110>,and<111>in these temperature ranges.The temperature-dependent Debye average velocity,hardness,melting temperature,and ultrasonic Grüneisen parameters(UGPs)were evaluated.The frac-ture/toughness(B/G)ratio in the current investigation was greater than 1.75,indicating that the ZrN/MgO(001)nanostructured layer was ductile in this temperature range.The selected materials fully satisfied the Born me-chanical stability requirement.At this ambient temperature,it has been computed how long thermal relaxation takes to complete and how ultrasonic waves are attenuated by thermo-elastic relaxation and phonon-phonon interaction mechanisms.These results,in combination with other well-known physical properties,can be applied to the non-destructive testing of materials for various industrial applications such as microelectronic devices,optical coatings,batteries,and solar cells.展开更多
This paper reports the application of the biomolecular probe sensor based on the tilted fiber Bragg grating （TFBG） surface plasma resonance （SPR） which can recognize the specificity of the specific molecule by dep...This paper reports the application of the biomolecular probe sensor based on the tilted fiber Bragg grating （TFBG） surface plasma resonance （SPR） which can recognize the specificity of the specific molecule by depositing sensitive biological membrane outside the active golden layer. The method of self-assembly was used to make the fixed sensitive biological membrane to achieve the best effect in the experiment. To illustrate the specific recognition of the DNA molecule, the TFBG-SPR biosensor was exposed to complementary DNA solutions with the concentration of 0.1 mmol/L and 0.05 mmol/L, respectively. The resonance wavelength of the TFBG-SPR biosensor increased gradually, indicating that the hybridization with the complementary DNA molecules changed the effective refractive index in the vicinity of the golden layer. Furthermore, the results illustrated the feasibility of the biomolecular probe sensor based on the TFBG surface plasma resonance for detecting the specific molecule.展开更多
文摘A review of our experience in range of electron spectroscopy of the physical vapor-phase deposition and growth of single- and multilayer nanostructures with atomic scale interfaces is presented. The foundation of an innovative methodology for the combined AES-EELS analysis of layered nanostructures is developed. The methodology includes: 1) determination of the composition, thickness, and the mechanism of phase transitions in nanocoatings under the probing depth most appropriated for the range of film thickness 1 - 10 ML;2) quantitative iteration Auger-analysis of the composition, thickness and growth mechanism of nanocoating;3) structural and phase analysis of nanocoatings with use of the analysis of position, shape and energy of the plasmon EELS peak and with subtracting the contribution from the substrate;4) analysis of phase transitions with use of the shift of the plasmon Auger-satellite and 5) non-destructive profiling of the composition of nanocoatings over depth with use of a dependence of the intensity and energy of EELS peaks on the value of the primary electron energy.
文摘We investigate a modified surface wave splitter with a double-layer structure, which consists of symmetrical metallic grating and an asymmetrical dielectric, using the finite-difference time-domain （FDTD） simulation method. The metal/dielectric interface structure at this two-side aperture can support bound waves of different wavelengths, thus guiding waves in opposite directions. The covered dielectric films play an important role in the enhancement and confinement of the diffraction wave by the waveguide modes. The simulation result shows that the optical intensities of the guided surface wave at wavelengths of 760-nm and 1000-nm are about 100 times and 4-5 times those of the weaker side, respectively, which means that the surface wave is split by the proposed device.
基金Supported by the National Natural Science Foundation of China(No.51372169)Natural Science Foundation of Tianjin(No.11JCZDJC17300)
文摘In the present work,hierarchical nanostructured titanium dioxide(TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr(TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased electrolyte containing 0.5wt% NH4F.The nanostructured TiO2 films exhibited three distinct types depending on the anodization time:top irregular nanopores(INP)/beneath regular nanopores(RNP),top INP/middle regular nanotubes(RNT)/bottom RNP and top RNT with underlying RNP.The evolution of the nanostructured TiO2 films with anodization time demonstrated that self-organizing nanopores formed at the very beginning and individual nanotubes originated from underlying nanopore dissolution.Furthermore,a modified two-stage self-organizing mechanism was introduced to illustrate the growth of the nanostructured TiO2 films.Compared with TLM titanium alloy matrix,the TiO2 films with special nano-structure hold better hydrophilicity and higher specific surface area,which lays the foundation for their biomedical applications.
基金supported by the National Natural Science Foundation for Excellent Young Scholars of China (51522402)the National Postdoctoral Program for Innovative Talents (BX20180034)+1 种基金the Fundamental Research Funds for the Central Universities (FRF-TP-18-045A1)China Postdoctoral Science Foundation (2018M641192)
文摘A novel layered hexagonal boron nitride/titanium dioxide(h-BN/TiO2) composite photocatalyst has been constructed by anchoring TiO2 nanoflakes on the surface of hBN flakes via a solvothermal method. The morphology and dispersion of TiO2 can be tuned by controlling the amount of flake h-BN. Benefiting from the unique hetero-structure, the photocatalytic performance of the obtained composite toward rhodamine B(Rh B) degradation is greatly enhanced, among which 12 wt% h-BN/TiO2 composites show 3.5 and 6.9 times higher degradation rate than the synthesized TiO2 and commercial TiO2(P25), respectively, and an excellent cycling stability has also been obtained. Moreover, the first-principles calculation reveals the synergetic catalytic effect between TiO2 and h-BN flake, which is found to be responsible for the significantly enhanced photocatalytic performance of h-BN/TiO2 composites.
基金National Key Research and Development Program of China(No.2016YFB0300700)Education and Scientific Research Project of Shanghai(No.19SG46)+2 种基金Natural Science Foundation of Shanghai(No.17ZR1440900)International Science and Technology Cooperation Program(No.CU03-29)Project of Shandong Province Higher Educational Science and Technology Program(No.J17KA017)。
文摘Using fast multiple rotation rolling(FMRR),a nanostructure layer was fabricated on the surface of Ti6Al4V alloy.The microstructure of the surface layer was investigated using optical microscopy,transmission electron microscopy,scanning electron microscopy,and X-ray diffraction.The results indicated that a nanostructured layer,with an average grain size of 72—83 nm,was obtained in the top surface layer,when the FMRR duration was 15 min.And the average grain size further reduced to 24—37 nm when the treatment duration increased to 45 min.High density dislocations,twins,and stacking faults were observed in the top surface layer.The microhardness of FMRR specimen,compared with original specimen,was significantly increased.A uniform,continuous and thicker compound layer was obtained in the top surface of FMRR sample,and the diffusion speed of N atom in the top surface layer was accelerated.FMRR treatment provides corrosion improvement.
文摘In the present study,we calculated the elastic,mechanical,and thermo-physical properties of Zirconium Nitride(ZrN)/Magnesium Oxide(MgO)(001)nanostructures in the temperature range of 50∼300 K using higher-order elastic constants.With two fundamental factors,nearest-neighbor distance and hardness parameter,in this tem-perature range,the second-and third-order elastic constants(SOECs and TOECs)are estimated using the Coulomb&Born-Mayer potential.The computed values of SOECs have been used to calculate Young’s modulus,thermal conductivity,Zener anisotropy,bulk modulus,thermal energy density,shear modulus,and Poisson’s ratio to as-sess the thermal and mechanical properties of the ZrN/MgO(001)nanostructured layer.Additionally,SOECs are used to calculate the wave velocities for shear as well as longitudinal modes of propagation along crystalline orientations<100>,<110>,and<111>in these temperature ranges.The temperature-dependent Debye average velocity,hardness,melting temperature,and ultrasonic Grüneisen parameters(UGPs)were evaluated.The frac-ture/toughness(B/G)ratio in the current investigation was greater than 1.75,indicating that the ZrN/MgO(001)nanostructured layer was ductile in this temperature range.The selected materials fully satisfied the Born me-chanical stability requirement.At this ambient temperature,it has been computed how long thermal relaxation takes to complete and how ultrasonic waves are attenuated by thermo-elastic relaxation and phonon-phonon interaction mechanisms.These results,in combination with other well-known physical properties,can be applied to the non-destructive testing of materials for various industrial applications such as microelectronic devices,optical coatings,batteries,and solar cells.
文摘This paper reports the application of the biomolecular probe sensor based on the tilted fiber Bragg grating （TFBG） surface plasma resonance （SPR） which can recognize the specificity of the specific molecule by depositing sensitive biological membrane outside the active golden layer. The method of self-assembly was used to make the fixed sensitive biological membrane to achieve the best effect in the experiment. To illustrate the specific recognition of the DNA molecule, the TFBG-SPR biosensor was exposed to complementary DNA solutions with the concentration of 0.1 mmol/L and 0.05 mmol/L, respectively. The resonance wavelength of the TFBG-SPR biosensor increased gradually, indicating that the hybridization with the complementary DNA molecules changed the effective refractive index in the vicinity of the golden layer. Furthermore, the results illustrated the feasibility of the biomolecular probe sensor based on the TFBG surface plasma resonance for detecting the specific molecule.
