This work was attempted to modify the current technology for thermal barrier coatings(TBCs) by adding an additional step of surface modification,namely,supersonic fine particles bombarding(SFPB) process,on bond co...This work was attempted to modify the current technology for thermal barrier coatings(TBCs) by adding an additional step of surface modification,namely,supersonic fine particles bombarding(SFPB) process,on bond coat before applying the topcoat.After isothermal oxidation at 1000 °C for different time,the surface state of the bond coat and its phase transformation were investigated using X-ray diffraction(XRD),scanning electron microscopy(SEM) equipped with energy-dispersive X-ray spectrometry(EDS),transmission electron microscopy(TEM) and Cr3+ luminescence spectroscopy.The dislocation density significantly increases after SFPB process,which can generate a large number of diffusion channels in the area of the surface of the bond coat.At the initial stage of isothermal oxidation,the diffusion velocity of Al in the bond coat significantly increases,leading to the formation of a layer of stable α-Al2O3 phase.A great number of Cr3+ positive ions can diffuse via diffusion channels during the transient state of isothermal oxidation,which can lead to the presence of(Al0.9Cr0.1)2O3 phase and accelerate the γ→θ→α phase transformation.Cr3+ luminescence spectroscopy measurement shows that the residual stress increases at the initial stage of isothermal oxidation and then decreases.The residual stress after isothermal oxidation for 310 h reduces to 0.63 GPa compared with 0.93 GPa after isothermal oxidation for 26 h.In order to prolong the lifespan of TBCs,a layer of continuous,dense and pure α-Al2O3 with high oxidation resistance at the interface between topcoat and bond coat can be obtained due to additional SFPB process.展开更多
The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identifi...The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identified by elemental analyses. UV and IR of the complexeshave been investigated. The UV spectra indicated that the complexes' ultraviolet absorption weremainly the ligands' absorption. The IR spectra showed that the IR spectra of complexes are differentfrom those of free ligands. The fluorescence properties of them were investigated by usingluminescence spectroscopy, the results showed that only three complexes appear as betterluminescence, they were Eu-benzoic acid, Eu-m-phthalic acid and Eu-phthalic acid, while the othersexhibited the ligands' wideband emission.展开更多
In this research, the absorbance and luminescence response of two osmium(II) phenathrane (phen) carbonyl complexes to various DNA, heparin and i-carrageenan polyanions were studied. The [Os(phen)<sub>2</sub&g...In this research, the absorbance and luminescence response of two osmium(II) phenathrane (phen) carbonyl complexes to various DNA, heparin and i-carrageenan polyanions were studied. The [Os(phen)<sub>2</sub>CO(L)]<sup>2+</sup> complexes with L either a 4-phenyl pyridine (4-phpy) or phenyl imidazole (phimd) group exhibit moderate luminescent intensity in the visible region, their intensities are highly altered by the addition of DNA and other polyanion samples. These luminescent responses to polyanions were also compared with the [Ru(phen)<sub>3</sub>]<sup>2+</sup> complex. In ethanol solution, the presence of polyanions significantly enhanced the luminescent emission intensity of [Os(phen)<sub>2</sub>CO(L)]<sup>2+</sup> complexes with a blue shift. While the polyanions all showed emission enhancement on the highly lumi-nescent [Ru(phen)<sub>3</sub>]<sup>2+</sup> complex in ethanol solution with a red spectra shift. The [Os(phen)<sub>2</sub>CO(L)] <sup>2+</sup> with (phimd) ligand has the lowest emission in ethanol solution, its intensity can be enhanced up to 11 times in the presence of DNA polyanions. This enhancement for all the complexes in ethanol is mainly due to their electrostatic interaction with the anion sites and with some degree of ligand intercalation into the polyanion hydrophobic structure which reduced the solvent quenching of the complexes. The blue shift of the (4-phpy) and particularly (phimd) Os(II)CO complexes indicate an insertion of the (4-phpy) or (phimd) group into the polymer chains. The two new Os(II)CO complexes has great potential to be used as luminescence sensors for DNA and polyanion detection in the low micro molar range with high sensitivity.展开更多
Monitoring of coating health was achieved by embedding sensor materials(MAl_(2)O_(4):Eu^(2+),Dy^(3+),M=Sr,Ba)in tribological coating.When the luminescence disappears under ultraviolet(UV)light,it means that the functi...Monitoring of coating health was achieved by embedding sensor materials(MAl_(2)O_(4):Eu^(2+),Dy^(3+),M=Sr,Ba)in tribological coating.When the luminescence disappears under ultraviolet(UV)light,it means that the functional coating is worn out and that recoating is needed.In this work,four types of alloy(Cu-14Al-X,Cu,Cu-Al,Al)composite coatings were investigated by vacuum pres sure-as sis ted sintering method.The composite coatings with different copper-aluminium alloy matrixes were compared by phase composition,microstructure,luminescence properties and tribological performance.The results indicate that the Cu-14Al-X matrix composite coating shows not only good resistance to wear but also exhibits strong green light emitting under ultraviolet(UV)light.It is the best wear-resistant self-sensitive coating which has potential industrial value.When the coating wore or broke,the emitting intensity will decrease or disappear.展开更多
The Eu(Ⅲ)nitrate complex of the meso-N,N’-bis(2-pyridylmethylene)-1,2-(R,S)-cyclohexanediamine ligand was synthesized and characterized by single crystal and powder X-ray diffraction.The crystal lattice of the compl...The Eu(Ⅲ)nitrate complex of the meso-N,N’-bis(2-pyridylmethylene)-1,2-(R,S)-cyclohexanediamine ligand was synthesized and characterized by single crystal and powder X-ray diffraction.The crystal lattice of the complex is capable of absorbing and desorbing selectively acetonitrile molecules,at 293 K upon an acetonitrile vapor pressure of^0.1×10^5 Pa.This process,which is partially reversible,can be easily followed by both powder X-ray diffraction(P-XRD)and Eu(III)luminescence spectroscopy.The acetonitrile molecule,located in the outer coordination sphere of the metal ion,does not affect the radiative transition probability of 5 D0 level of Eu(Ⅲ)and also it does not activate further non-radiative channels from this level.On the other hand,this molecule is capable of affecting the energy position and intensities of the crystal field components of the 5 D0→7 F2 transition.The complex in solid form can be considered a promising material for the optical sensing of acetonitrile vapors.展开更多
基金Foundation item: Project (50575220) supported by the National Natural Science Foundation of ChinaProject supported by State Key Laboratory of Engines,China
文摘This work was attempted to modify the current technology for thermal barrier coatings(TBCs) by adding an additional step of surface modification,namely,supersonic fine particles bombarding(SFPB) process,on bond coat before applying the topcoat.After isothermal oxidation at 1000 °C for different time,the surface state of the bond coat and its phase transformation were investigated using X-ray diffraction(XRD),scanning electron microscopy(SEM) equipped with energy-dispersive X-ray spectrometry(EDS),transmission electron microscopy(TEM) and Cr3+ luminescence spectroscopy.The dislocation density significantly increases after SFPB process,which can generate a large number of diffusion channels in the area of the surface of the bond coat.At the initial stage of isothermal oxidation,the diffusion velocity of Al in the bond coat significantly increases,leading to the formation of a layer of stable α-Al2O3 phase.A great number of Cr3+ positive ions can diffuse via diffusion channels during the transient state of isothermal oxidation,which can lead to the presence of(Al0.9Cr0.1)2O3 phase and accelerate the γ→θ→α phase transformation.Cr3+ luminescence spectroscopy measurement shows that the residual stress increases at the initial stage of isothermal oxidation and then decreases.The residual stress after isothermal oxidation for 310 h reduces to 0.63 GPa compared with 0.93 GPa after isothermal oxidation for 26 h.In order to prolong the lifespan of TBCs,a layer of continuous,dense and pure α-Al2O3 with high oxidation resistance at the interface between topcoat and bond coat can be obtained due to additional SFPB process.
文摘The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identified by elemental analyses. UV and IR of the complexeshave been investigated. The UV spectra indicated that the complexes' ultraviolet absorption weremainly the ligands' absorption. The IR spectra showed that the IR spectra of complexes are differentfrom those of free ligands. The fluorescence properties of them were investigated by usingluminescence spectroscopy, the results showed that only three complexes appear as betterluminescence, they were Eu-benzoic acid, Eu-m-phthalic acid and Eu-phthalic acid, while the othersexhibited the ligands' wideband emission.
文摘In this research, the absorbance and luminescence response of two osmium(II) phenathrane (phen) carbonyl complexes to various DNA, heparin and i-carrageenan polyanions were studied. The [Os(phen)<sub>2</sub>CO(L)]<sup>2+</sup> complexes with L either a 4-phenyl pyridine (4-phpy) or phenyl imidazole (phimd) group exhibit moderate luminescent intensity in the visible region, their intensities are highly altered by the addition of DNA and other polyanion samples. These luminescent responses to polyanions were also compared with the [Ru(phen)<sub>3</sub>]<sup>2+</sup> complex. In ethanol solution, the presence of polyanions significantly enhanced the luminescent emission intensity of [Os(phen)<sub>2</sub>CO(L)]<sup>2+</sup> complexes with a blue shift. While the polyanions all showed emission enhancement on the highly lumi-nescent [Ru(phen)<sub>3</sub>]<sup>2+</sup> complex in ethanol solution with a red spectra shift. The [Os(phen)<sub>2</sub>CO(L)] <sup>2+</sup> with (phimd) ligand has the lowest emission in ethanol solution, its intensity can be enhanced up to 11 times in the presence of DNA polyanions. This enhancement for all the complexes in ethanol is mainly due to their electrostatic interaction with the anion sites and with some degree of ligand intercalation into the polyanion hydrophobic structure which reduced the solvent quenching of the complexes. The blue shift of the (4-phpy) and particularly (phimd) Os(II)CO complexes indicate an insertion of the (4-phpy) or (phimd) group into the polymer chains. The two new Os(II)CO complexes has great potential to be used as luminescence sensors for DNA and polyanion detection in the low micro molar range with high sensitivity.
基金financially supported by the National Natural Science Foundation of China(No.51674130)Natural Science Fund of Gansu Province of China(No.1508RJZA049)the International Science and Technology Cooperation Projects(No.2015DFR51090)。
文摘Monitoring of coating health was achieved by embedding sensor materials(MAl_(2)O_(4):Eu^(2+),Dy^(3+),M=Sr,Ba)in tribological coating.When the luminescence disappears under ultraviolet(UV)light,it means that the functional coating is worn out and that recoating is needed.In this work,four types of alloy(Cu-14Al-X,Cu,Cu-Al,Al)composite coatings were investigated by vacuum pres sure-as sis ted sintering method.The composite coatings with different copper-aluminium alloy matrixes were compared by phase composition,microstructure,luminescence properties and tribological performance.The results indicate that the Cu-14Al-X matrix composite coating shows not only good resistance to wear but also exhibits strong green light emitting under ultraviolet(UV)light.It is the best wear-resistant self-sensitive coating which has potential industrial value.When the coating wore or broke,the emitting intensity will decrease or disappear.
文摘The Eu(Ⅲ)nitrate complex of the meso-N,N’-bis(2-pyridylmethylene)-1,2-(R,S)-cyclohexanediamine ligand was synthesized and characterized by single crystal and powder X-ray diffraction.The crystal lattice of the complex is capable of absorbing and desorbing selectively acetonitrile molecules,at 293 K upon an acetonitrile vapor pressure of^0.1×10^5 Pa.This process,which is partially reversible,can be easily followed by both powder X-ray diffraction(P-XRD)and Eu(III)luminescence spectroscopy.The acetonitrile molecule,located in the outer coordination sphere of the metal ion,does not affect the radiative transition probability of 5 D0 level of Eu(Ⅲ)and also it does not activate further non-radiative channels from this level.On the other hand,this molecule is capable of affecting the energy position and intensities of the crystal field components of the 5 D0→7 F2 transition.The complex in solid form can be considered a promising material for the optical sensing of acetonitrile vapors.