The phosphors of ABF_4:Eu^(2+)and A_2SiF_6:Eu^(2+)(A=Na,K,Rb,Cs)have been synthesized,and the crystallographic data obtained accord with ASTM.In these materials,the f→f sharp lines emissions of Eu^(2+) were observed....The phosphors of ABF_4:Eu^(2+)and A_2SiF_6:Eu^(2+)(A=Na,K,Rb,Cs)have been synthesized,and the crystallographic data obtained accord with ASTM.In these materials,the f→f sharp lines emissions of Eu^(2+) were observed.The coordination numbers of Eu^(2+)in both NaBF_4 and Na_2SiF_6 hosts are less than 8.展开更多
A new nickel（II） complex [NiL2]（DMF）4 （HL = 2＇-[4-N,N＇-（dimethylamino- benzylidene）]-3,5-dihydroxybenzoylhydrazide） has been synthesized and its structure was characterized by IR,UV-Vis,1H NMR and elemental ...A new nickel（II） complex [NiL2]（DMF）4 （HL = 2＇-[4-N,N＇-（dimethylamino- benzylidene）]-3,5-dihydroxybenzoylhydrazide） has been synthesized and its structure was characterized by IR,UV-Vis,1H NMR and elemental analysis. The fluorescence emission mechanism of the complex was discussed by fluorimetric spectra. The single-crystal structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system,space group P1 with a = 0.9918（4）,b = 1.1297（4）,c = 1.1331（4） nm,α = 76.860（7）,β = 75.105（6）,γ = 89.022（7）°,V = 1.1936（8） nm^3,Z = 1,μ = 0.472 mm^-1,Dc = 1.319 g/cm^3,F（000） = 502 and Rint = 0.0913. In the title compound,the nickel（II） atom is four-coordinated with two nitrogen atoms from amide and two oxygen atoms from keto group. The complex is centrosymmetric with nickel located at the center.展开更多
The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was...The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was identified by means of 1H NMR,MS and IR spectrometries. The single crystal structure of \{3-phenyl\}-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was determined by X-ray diffraction. The preliminary bioassays have shown that the title compound exhibits the weak activities of fungicide and plant growth regulator.展开更多
By using an Ar^＋ ion laser, a tunable Rh6G dye laser（linewidth： 0.5 cm^-1） pumped by the second harmonic of a YAG：Nd laser and an 899-21 dye laser as light sources and using a monochromator, a phase-locking ampli...By using an Ar^＋ ion laser, a tunable Rh6G dye laser（linewidth： 0.5 cm^-1） pumped by the second harmonic of a YAG：Nd laser and an 899-21 dye laser as light sources and using a monochromator, a phase-locking amplifier and a computer as the data detecting system, the spectra and spectral hole burning of Eu^3＋：Y2SiO5 crystal were researched in this paper.Photoluminescence excitation spectrum and site selective fluorescence spectrum were detected at room temperature and 77 K. Hole burning experiments were reached at 16 K. A spectral hole with hole width of about 80 MHz were detected and it could be kept for 10 h.展开更多
The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-...The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal crystallizes in the orthorhombic system, space group Pbca with a = 14.366（4）, b = 15.159（4）, c = 16.443（5）A, V = 3580.9（17）/A3 Z = 4, De = 1.461 g/cm^3, /t = 0.253 mm^-1, F（000） = 1640, R = 0.0618 and wR = 0.1525 for 1615 observed reflections （I 〉 2σ（I））. In the structure of the title compound, a two-dimensional supramolecular layer is formed via intermolecular hydrogen bonding interactions.展开更多
Effective utilization of hot electrons generated from the decay of surface plasmon resonance in metal nanoparticles is conductive to improve solar water splitting efficiency.Herein,Ag nanoparticles and reduced graphen...Effective utilization of hot electrons generated from the decay of surface plasmon resonance in metal nanoparticles is conductive to improve solar water splitting efficiency.Herein,Ag nanoparticles and reduced graphene oxide(rGO)co-decorated hierarchical TiO2 nanoring/nanotube arrays(TiO2 R/T)were facilely fabricated by using two-step electrochemical anodization,electrodeposition,and photoreduction methods.Comparative studies were conducted to elucidate the effects of rGO and Ag on the morphology,photoresponse,charge transfer,and photoelectric properties of TiO2.Firstly,scanning electron microscope images confirm that the Ag nanoparticles adhered on TiO2 R/T and TiO2 R/T-rGO have similar diameter of 20 nm except for TiO2 R-rGO/T.Then,the UV-Vis DRS and scatter spectra reveal that the optical property of the Ag-TiO2 R/T-rGO ternary composite is enhanced,ascribing to the visible light absorption of plasmonic Ag nanoparticles and the weakening effect of rGO on light scattering.Meanwhile,intensity-modulated photocurrent spectroscopy and photoluminescence spectra demonstrate that rGO can promote the hot electrons transfer from Ag nanoparticles to Ti substrate,reducing the photogenerated electron-hole recombination.Finally,Ag-TiO2 R/T-rGO photoanode exhibits high photocurrent density(0.98 mA cm?2)and photovoltage(0.90 V),and the stable H2 evolution rate of 413μL h?1 cm?2 within 1.5 h under AM 1.5 which exceeds by 1.30 times than that of pristine TiO2 R/T.In line with the above results,this work provides a reliable route synergizing rGO with plasmonic metal nanoparticles for photocatalysis,in which,rGO presents a broad absorption spectrum and effective photogenerated electrons transfer.展开更多
In order to improve the red luminescent properties,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)was selected as a blue persistent luminescent donor phosphor,while light conversion agent was utilized to tune the persistent lumin...In order to improve the red luminescent properties,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)was selected as a blue persistent luminescent donor phosphor,while light conversion agent was utilized to tune the persistent luminescent spectra from blue to red.Composite red luminescent material Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)/light conversion agent(SMED/LCA)was fabricated with light conversion agent and Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)at a certain mass ratio.SiO_(2)(Al2 O_(3) or MgF2)were coated on the surface of SMED/LCA through heterogeneous deposition method.The structural and optical characteristics of the resulting samples were launched in terms of X-ray diffraction and emission spectrum as well as afterglow brightness.The results demonstrate that the emission spectrum exhibits two emission bands,and the peaks are located at around 470 and 615 nm.SiO_(2),Al_(2)O_(3) and MgF_(2) are coated on the surface of SMED/LCA like a protective shell to maintain its stability and luminescent properties,the afterglow initial brightness is still up to 0.37 cd/m^(2) and the afterglow color purity calculated from CIE color coordinates is basically unchanged.展开更多
Ce^(3+)and Eu^(2+)doped alkaline earth aluminates MAl_(2)O_(4)(M=Ca,Sr,Ba)were prepared by single-step combustion synthesis at low temperature(600℃).X-ray diffraction(XRD)analysis confirmed the formation of BaAl_(2)O...Ce^(3+)and Eu^(2+)doped alkaline earth aluminates MAl_(2)O_(4)(M=Ca,Sr,Ba)were prepared by single-step combustion synthesis at low temperature(600℃).X-ray diffraction(XRD)analysis confirmed the formation of BaAl_(2)O_(4),CaAl_(2)O_(4),and SrAl_(2)O_(4).Photoluminescence spectra and optimal luminescent properties of Ce^(3+)and Eu^(2+)doped MAl_(2)O_(4) phosphors were studied.Relation between Eu^(2+)and Ce^(3+)f-d transitions was explained.Spectroscopic properties known for Ce^(3+)were used to predict those of Eu^(2+)by using Dorenbos’method.The values thus calculated were in excellent agreement with the experimental results.The preferential substitution of Ce^(3+)and Eu^(2+)at different Ba^(2+),Sr^(2+),Ca^(2+)crystallographic sites was discussed.The dependence of emission wavelengths of Ce^(3+)and Eu^(2+)on local symmetry of different crystallographic sites was also studied by using Van Uitert’s empirical relation.Experimental results matched excellently with the predictions of Dorenbos’and Van Uitert’s models.展开更多
In conditions of monochromatic excitation (λexc=337.1), the spectral dependence of the efficiency of fluorescence quenching αλ of humic acids samples by Cd2+ and Cu2+ ions was studied. The difference of αλ depend...In conditions of monochromatic excitation (λexc=337.1), the spectral dependence of the efficiency of fluorescence quenching αλ of humic acids samples by Cd2+ and Cu2+ ions was studied. The difference of αλ dependencies for these ions was established. In the spectral range 350 - 650 nm, changes of the αλ for Cd2+ ion are markedly different from the magnitude for changes αλ, which occur for ion Cu2+. The interpretation of mismatch dependences obtained αλ ions Cd2+ and Cu2+ is carried out within the concept of the availability of different sites, due to the difference in ionic radii (0.108 nm and 0.08 nm for Cd2+ and Cu2+, respectively).展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘The phosphors of ABF_4:Eu^(2+)and A_2SiF_6:Eu^(2+)(A=Na,K,Rb,Cs)have been synthesized,and the crystallographic data obtained accord with ASTM.In these materials,the f→f sharp lines emissions of Eu^(2+) were observed.The coordination numbers of Eu^(2+)in both NaBF_4 and Na_2SiF_6 hosts are less than 8.
基金Project supported by the Natural Science Foundation of Zhejiang Province (Y406049)Education Committee Foundation of Zhejiang Province (No. 20060079)
文摘A new nickel（II） complex [NiL2]（DMF）4 （HL = 2＇-[4-N,N＇-（dimethylamino- benzylidene）]-3,5-dihydroxybenzoylhydrazide） has been synthesized and its structure was characterized by IR,UV-Vis,1H NMR and elemental analysis. The fluorescence emission mechanism of the complex was discussed by fluorimetric spectra. The single-crystal structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system,space group P1 with a = 0.9918（4）,b = 1.1297（4）,c = 1.1331（4） nm,α = 76.860（7）,β = 75.105（6）,γ = 89.022（7）°,V = 1.1936（8） nm^3,Z = 1,μ = 0.472 mm^-1,Dc = 1.319 g/cm^3,F（000） = 502 and Rint = 0.0913. In the title compound,the nickel（II） atom is four-coordinated with two nitrogen atoms from amide and two oxygen atoms from keto group. The complex is centrosymmetric with nickel located at the center.
文摘The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was identified by means of 1H NMR,MS and IR spectrometries. The single crystal structure of \{3-phenyl\}-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was determined by X-ray diffraction. The preliminary bioassays have shown that the title compound exhibits the weak activities of fungicide and plant growth regulator.
文摘By using an Ar^＋ ion laser, a tunable Rh6G dye laser（linewidth： 0.5 cm^-1） pumped by the second harmonic of a YAG：Nd laser and an 899-21 dye laser as light sources and using a monochromator, a phase-locking amplifier and a computer as the data detecting system, the spectra and spectral hole burning of Eu^3＋：Y2SiO5 crystal were researched in this paper.Photoluminescence excitation spectrum and site selective fluorescence spectrum were detected at room temperature and 77 K. Hole burning experiments were reached at 16 K. A spectral hole with hole width of about 80 MHz were detected and it could be kept for 10 h.
基金supported by the National Natural Science Foundation of China (No. 20401008)
文摘The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal crystallizes in the orthorhombic system, space group Pbca with a = 14.366（4）, b = 15.159（4）, c = 16.443（5）A, V = 3580.9（17）/A3 Z = 4, De = 1.461 g/cm^3, /t = 0.253 mm^-1, F（000） = 1640, R = 0.0618 and wR = 0.1525 for 1615 observed reflections （I 〉 2σ（I））. In the structure of the title compound, a two-dimensional supramolecular layer is formed via intermolecular hydrogen bonding interactions.
基金the National Natural Science Foundation of China(Grant No.51776009)for the financial support.
文摘Effective utilization of hot electrons generated from the decay of surface plasmon resonance in metal nanoparticles is conductive to improve solar water splitting efficiency.Herein,Ag nanoparticles and reduced graphene oxide(rGO)co-decorated hierarchical TiO2 nanoring/nanotube arrays(TiO2 R/T)were facilely fabricated by using two-step electrochemical anodization,electrodeposition,and photoreduction methods.Comparative studies were conducted to elucidate the effects of rGO and Ag on the morphology,photoresponse,charge transfer,and photoelectric properties of TiO2.Firstly,scanning electron microscope images confirm that the Ag nanoparticles adhered on TiO2 R/T and TiO2 R/T-rGO have similar diameter of 20 nm except for TiO2 R-rGO/T.Then,the UV-Vis DRS and scatter spectra reveal that the optical property of the Ag-TiO2 R/T-rGO ternary composite is enhanced,ascribing to the visible light absorption of plasmonic Ag nanoparticles and the weakening effect of rGO on light scattering.Meanwhile,intensity-modulated photocurrent spectroscopy and photoluminescence spectra demonstrate that rGO can promote the hot electrons transfer from Ag nanoparticles to Ti substrate,reducing the photogenerated electron-hole recombination.Finally,Ag-TiO2 R/T-rGO photoanode exhibits high photocurrent density(0.98 mA cm?2)and photovoltage(0.90 V),and the stable H2 evolution rate of 413μL h?1 cm?2 within 1.5 h under AM 1.5 which exceeds by 1.30 times than that of pristine TiO2 R/T.In line with the above results,this work provides a reliable route synergizing rGO with plasmonic metal nanoparticles for photocatalysis,in which,rGO presents a broad absorption spectrum and effective photogenerated electrons transfer.
基金Project supported by Natural Science Foundation of Jiangsu Province(BK20171140,BK20180629)National Natural Science Foundation of China(51803076)。
文摘In order to improve the red luminescent properties,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)was selected as a blue persistent luminescent donor phosphor,while light conversion agent was utilized to tune the persistent luminescent spectra from blue to red.Composite red luminescent material Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)/light conversion agent(SMED/LCA)was fabricated with light conversion agent and Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+)at a certain mass ratio.SiO_(2)(Al2 O_(3) or MgF2)were coated on the surface of SMED/LCA through heterogeneous deposition method.The structural and optical characteristics of the resulting samples were launched in terms of X-ray diffraction and emission spectrum as well as afterglow brightness.The results demonstrate that the emission spectrum exhibits two emission bands,and the peaks are located at around 470 and 615 nm.SiO_(2),Al_(2)O_(3) and MgF_(2) are coated on the surface of SMED/LCA like a protective shell to maintain its stability and luminescent properties,the afterglow initial brightness is still up to 0.37 cd/m^(2) and the afterglow color purity calculated from CIE color coordinates is basically unchanged.
文摘Ce^(3+)and Eu^(2+)doped alkaline earth aluminates MAl_(2)O_(4)(M=Ca,Sr,Ba)were prepared by single-step combustion synthesis at low temperature(600℃).X-ray diffraction(XRD)analysis confirmed the formation of BaAl_(2)O_(4),CaAl_(2)O_(4),and SrAl_(2)O_(4).Photoluminescence spectra and optimal luminescent properties of Ce^(3+)and Eu^(2+)doped MAl_(2)O_(4) phosphors were studied.Relation between Eu^(2+)and Ce^(3+)f-d transitions was explained.Spectroscopic properties known for Ce^(3+)were used to predict those of Eu^(2+)by using Dorenbos’method.The values thus calculated were in excellent agreement with the experimental results.The preferential substitution of Ce^(3+)and Eu^(2+)at different Ba^(2+),Sr^(2+),Ca^(2+)crystallographic sites was discussed.The dependence of emission wavelengths of Ce^(3+)and Eu^(2+)on local symmetry of different crystallographic sites was also studied by using Van Uitert’s empirical relation.Experimental results matched excellently with the predictions of Dorenbos’and Van Uitert’s models.
文摘In conditions of monochromatic excitation (λexc=337.1), the spectral dependence of the efficiency of fluorescence quenching αλ of humic acids samples by Cd2+ and Cu2+ ions was studied. The difference of αλ dependencies for these ions was established. In the spectral range 350 - 650 nm, changes of the αλ for Cd2+ ion are markedly different from the magnitude for changes αλ, which occur for ion Cu2+. The interpretation of mismatch dependences obtained αλ ions Cd2+ and Cu2+ is carried out within the concept of the availability of different sites, due to the difference in ionic radii (0.108 nm and 0.08 nm for Cd2+ and Cu2+, respectively).
