Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of...Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of montmorillonite (MT) by ion exchange and coordination reaction of L with the Tb^3+ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL (NO3) ]^2+-MT and [TbL]^3+-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing (d001) approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.展开更多
Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impreg...Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.展开更多
A novel rare earth luminescent material La2O2CO3 was synthesized successfully by sintering the mixture of La2(CO3)3 and KCl powders. The XRD results revealed that the additive KCl not only affected the crystal form an...A novel rare earth luminescent material La2O2CO3 was synthesized successfully by sintering the mixture of La2(CO3)3 and KCl powders. The XRD results revealed that the additive KCl not only affected the crystal form and crystallinity of the final product, but also greatly promoted its luminescence, compared with the products without adding KCl. The as-prepared material showed a strong green emission band centered at 470 nm under the excitation of 325 nm. Our experimental results indicated that the crystal form of La2O2CO3 affected its luminescent properties significantly. According to the primary analysis, the green emission might be related to the oxygen vacancies in La2O2CO3 lattice.展开更多
Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth ...Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth luminescent materials were used owing to their active light emission and reusability.Additionally,solar lightemitting diode lights and car-light reflection were utilised to increase the recognition and reliability of reflective cat eyes.Along with carbon reduction,this can save energy and enhance road safety.This study considered the Theory of Inventive Problem Solving and a literature review to analyse the issues in existing products.Then,expert interviews were conducted to screen projects and develop product design policies.Finally,the ratio of light-storage materials was experimentally determined and the prototypes implemented.This cat’s eye addresses the shortcomings identified in previous analyses of existing products.We applied energy storage environmental protection materials,together with material proportioning(which balanced warning efficiency against cost-effectiveness)to develop diversified modular kits;these were flexible in terms of quantity and easily assembled.This study achieved four key objectives:(1)reducing the research and development costs of the manufacturer;(2)offering buyers a diverse suite of products;(3)responding to a need to improve diverse road user safety;and(4)reducing government procurement costs for safety warning products.The results provide a reference for the creative modular design of energy-saving products for public road safety planning in various industries.展开更多
Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properti...Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.展开更多
Due to the outbreak of |x-19,colleges and universities have actively responded to the call of the state to carry out online teaching in completing their teaching tasks.After the epidemic,the online and offline hybrid ...Due to the outbreak of |x-19,colleges and universities have actively responded to the call of the state to carry out online teaching in completing their teaching tasks.After the epidemic,the online and offline hybrid teaching has become a novel mode of teaching which meets the requirements of teaching reform and the information society.This teaching method integrates both the online and offline teaching which plays an important role in enhancing teaching qualities and learning experiences.However,due to the lack of experience,there are some issues occurring in the teaching process of this method.The Luminescent Materials and Applications course is used as the subject in this article.The difficulties in traditional offline teaching as well as the advantages,detailed course construction process,and effectiveness evaluation of hybrid teaching are summarized and meticulously analyzed.In regard to that,the application of the online and offline hybrid teaching in the Luminescent Materials and Applications course is beneficial to the learning of professional knowledge and the cultivation of students'scientific literacy.Therefore,it is an effective way to improve and enrich this course by using the online and offline hybrid teaching method.展开更多
Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymeriz...Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.展开更多
A new method was reported for surface modification of an up-conversion luminescence material with hydrosulfide group. The factors that may influence the surface modification,such as reaction time,amount of catalyzer a...A new method was reported for surface modification of an up-conversion luminescence material with hydrosulfide group. The factors that may influence the surface modification,such as reaction time,amount of catalyzer and modifier,and reaction solvent,were investigated. The optimal conditions were that the reaction time,the quantity of the basic catalyzer,the quantity of modifier and the volume of reaction solvent were 40 min,1.0,1.0,and 40 mL,respectively. The results indicated that hydrosulfide group content modified on the surface of up-conversion luminescence material reached to 0.1430 mmol/g,and this modified up-conversion luminescence material could be widely used in the study of structure of protein and the property of microenvironment.展开更多
Persistent luminescence (PersL) materials,as environmentally friendly and energy-saving materials,have broad application prospects in many fields such as lighting,chemistry and even biomedicine.However,studies on the ...Persistent luminescence (PersL) materials,as environmentally friendly and energy-saving materials,have broad application prospects in many fields such as lighting,chemistry and even biomedicine.However,studies on the types,performances and mechanism of PersL materials are still insufficient,which significantly restricts their development and application.Under this consideration,we successfully synthesized a yellow PersL material CaSrGa_(4)O_(8)(CSG).The crystal structure was studied in detail through Rotation Electron Diffraction (RED) and Powder X-ray Diffraction (PXRD).What’s more,by co-doping Mn^(2+) and Yb^(3+),the afterglow brightness of CSG could be increased by nearly 20 times,and the afterglow duration could reach more than 6 h.It is worth mentioning that the samples also have excellent performances in mechanical luminescence (ML),photostimulated luminescence (PSL) and cathodoluminescence (CL),which was also investigated systematically.Finally,an anti-counterfeiting label was designed by the samples to reveal the potential of their application in anti-counterfeiting.The results showed that our research not only provided a new candidate PersL material for multifunctional applications,but also gave good help for studying the physical and chemical properties of CSG.展开更多
The combinatorial material chip approach is an excellent innovation for inorganic functional material research, and it can discover and screen new materials efficiently. In the present work, the approach was used to f...The combinatorial material chip approach is an excellent innovation for inorganic functional material research, and it can discover and screen new materials efficiently. In the present work, the approach was used to find quickly and improve gadolinium aluminate phosphors (Gd_ 1-xAl_yO_z∶RE_x). Under UV lamp excited (λ_ ex=254 nm) the Gd_ 1-xAl_yO_z∶RE_x phosphor material chip evaluation shows that the suitable n(Al)∶n(Gd) in host materials is 1∶1 for Eu and Tb ion activators. The luminescence character coherence between combinatorial material chip and parallelism powder samples produced by nitric-citric process was also confirmed.展开更多
Surface modification of up-conversion luminescence materials (Na[Y0.57Yb0.39Er0.04]F4 modified by amino groups) by grafting and modifying with aldehyde groups was studied by means of Fourier transform infrared spect...Surface modification of up-conversion luminescence materials (Na[Y0.57Yb0.39Er0.04]F4 modified by amino groups) by grafting and modifying with aldehyde groups was studied by means of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and emission spectrum (EM). The surface modification effect was compared using two different finishhag agents, p-phthalaldehyde and glutaraldehyde. It was found that the surface of up-conversion luminescence materials could be modified by aldehyde groups of the two finishing agents, the systematic dispersibility and the thermostability of the up-conversion luminescence material modified by p-phthalaldehyde were better than those of the material modified by glutaraldehyde, and the luminous intensity of the material modified by p-phthalaldehyde was increased. The AI (the ratio of the suspended segmental quality in the specimen to the total mass of the specimen) of the material modified by p-phthalaldehyde was higher than that of the material modified by glutaraldehyde. It is obviously seen that the embellishment effect of p-phthalaldehyde as a finishing agent was better than that of glutaraldehyde. In addition, the reasons why p-phthalaldehyde is a good finishing agent are also explained.展开更多
Progress of studies on various multi-color long afterglow luminescence materials was reviewed.Two luminescent mechanism of long afterglow behavior were discussed.Further research and development prospects about the ma...Progress of studies on various multi-color long afterglow luminescence materials was reviewed.Two luminescent mechanism of long afterglow behavior were discussed.Further research and development prospects about the materials were proposed.展开更多
The polycrystalline Sr_9Ca(PO_4)_6Cl_2:Eu has been synthesized by solid state reaction.The reaction condition,the appropriate raw materials and their quantity used,which may affect the photostimulable luminescence (PS...The polycrystalline Sr_9Ca(PO_4)_6Cl_2:Eu has been synthesized by solid state reaction.The reaction condition,the appropriate raw materials and their quantity used,which may affect the photostimulable luminescence (PSL),have been systematically inves- tigated.The properties of this PSL phosphor as a material for storing and reproducing the X-ray image in computer-aided radiography have been reported briefly.展开更多
The study on the effects of SrO/Al 2O 3 molar ratio on the crystalline phases and photoluminescence characteristics of strontium aluminate phosphors co-activated with Eu 2+ and Dy 3+ were conducted by X-ray po...The study on the effects of SrO/Al 2O 3 molar ratio on the crystalline phases and photoluminescence characteristics of strontium aluminate phosphors co-activated with Eu 2+ and Dy 3+ were conducted by X-ray powder diffractometry, fluorescence spectrometer and photometer. The strontium aluminate luminescent materials with different SrO/Al 2O 3 molar ratio emit the visible lights with different color tone after removal of excitation. The peak wavelengths of the emission spectra drift in the direction of short wave, the quantity of Sr 4Al 14O 25 crystalline phase increases and the afterglow time lengthens with the SrO/Al 2O 3 reduction. The results show that when the SrO/Al 2O 3 molar ratio is near 1, the photoluminescence materials have high luminescent intensity, and when it is near 0.75, they have long afterglow time. However, when SrO/Al 2O 3 molar ratio is more than 1, the luminescent materials appear strong alkaline in water solution; when SrO/Al 2O 3 molar ratio is much less than 0.75, the samples need a higher temperature to be sintered.展开更多
Long afterglow phosphors MAl2O4:Eu^2+ , Dy^3+ (M = Ca, Sr, Ba) were synthesized by microemulsion method, and their crystal structure and luminescent properties were compared and investigated. XRD patterns of samp...Long afterglow phosphors MAl2O4:Eu^2+ , Dy^3+ (M = Ca, Sr, Ba) were synthesized by microemulsion method, and their crystal structure and luminescent properties were compared and investigated. XRD patterns of samples indicate that phosphors CaAl2O4:Eu^2+, Dy^3+ and SrAl2O4 : Eu^2+, Dy^3+ are with monoelinie crystal structure and phosphor BaAl2O4:Eu^2+ , Dy^3+ is with hexagonal crystal structure. The wide range of excitation spectrum of phosphors MAl2O4: Eu^2 + , Dy^3+ (M = Ca,Sr, Ba) indicates that the luminescent materials can he excited by light from ultraviolet ray to visible light and the maximum emission wavelength of phosphors MAl2O4:Eu^2+ , Dy^3+ (M = Ca, Sr, Ba) is found mainly at λem of 440 nm (M = Ca), 520 nm (M = Sr) and 496 nm (M = Ba) respectively, the corresponding colors of emission light are blue, green and eyna-green respectively. The afterglow decay tendency of phosphors can he summarized as three processes: initial rapid decay, intermediate transitional decay and very long slow decay. Afterglow decay curves coincide with formula I = At^ - n, and the sequence of afterglow intensity and time is Sr 〉 Ca 〉 Ba.展开更多
The translucent GGAG:Ce/glass composites are prepared successfully by ball-milling,tableting,and pressureless sintering.The thickness of composites is about 400μm.The x-ray diffraction(XRD),differential scanning calo...The translucent GGAG:Ce/glass composites are prepared successfully by ball-milling,tableting,and pressureless sintering.The thickness of composites is about 400μm.The x-ray diffraction(XRD),differential scanning calorimetry(DSC),density of composite materials are measured and discussed systematically.The scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS)elemental mapping are employed to analyze the particle size,the shape of powders,and the distribution of GGAG:Ce particles in the glass matrix,respectively.The decay time,ultraviolet,(UV),x-ray excitation luminescence spectra,and temperature spectra are studied.The results show that the composite materials have high light output,good thermostability,and short decay time.The method adopted in this work is an effective method to reduce the preparation time and cost of the sample.The ultralow afterglow indicates that the composite materials have an opportunity to be used for x-ray detection and imaging.展开更多
Precursor of SrAl_2O_4∶Eu, Dy phosphor was prepared by co-precipitation method, in which dispersing agent was added to control particle size. Microwave radiation method was used to synthesize SrAl_2O_4∶Eu, Dy phosph...Precursor of SrAl_2O_4∶Eu, Dy phosphor was prepared by co-precipitation method, in which dispersing agent was added to control particle size. Microwave radiation method was used to synthesize SrAl_2O_4∶Eu, Dy phosphors. Experimental results show that the precursor was composed of crystalline ammonium dawsonite hydrate and strontium carbonate, and the adding of dispersing agent can effectively diminish precursor size. The precursor can be transformed to pure SrAl_2O_4 phase after being calcined for 40 min in microwave chamber. The phosphors possess good persistent luminescent properties, finer grain size ranged from 0.2 μm to 5 μm and better size distribution than that of solid-state reaction. The doping of B^(3+) will result in the increasing of crystallite size, but can effectively improve phosphors′ persistent luminescent properties.展开更多
Blue luminescent compounds T1―T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1 H NMR,13 C NMR and high resolution mass spectrometry(HRMS).Four co...Blue luminescent compounds T1―T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1 H NMR,13 C NMR and high resolution mass spectrometry(HRMS).Four compounds T1―T4 exhibit excellent solubility in common solvents and good film forming properties.Quantum chemical calculations show that compounds T1―T4 have asymmetric linear structures and the proper highest occupied molecular orbital(HOMO) levels.The UV-Vis absorption and fluorescence emission spectra of the four compounds in dilute chloroform solutions and on the solid films were measured.It reveals that compounds T1―T4 exhibit similar spectral behavior,suggesting that these compounds can form amorphous state in solid films.The calculated absorption and emission spectra of compounds T1―T4 are in good agreement with experimentally determined ones.Compounds T1―T4 have absolute fluorescence quantum yield above 17% in dilute chloroform solutions.Four compounds possess high glass-transition temperature(T g) exceeding 97 ℃ and the maximum T g is 155.28 ℃ for compound T3.Cyclic voltammetry measurements show that these compounds have proper HOMO levels in a range of-5.01―-5.13 eV for hole injection.The properties of compounds T1―T4 indicate that these compounds are candidates for the application in organic light-emitting devices(OLEDs) as hole-transporting materials(HTMs).展开更多
CaO-SiO2-B2O3 :Sm2O3 glasses were synthesized in air atmosphere with conventional high temperature process. The optimal temperature of synthesis, the absorption spectrum and the luminescent properties of the glasses ...CaO-SiO2-B2O3 :Sm2O3 glasses were synthesized in air atmosphere with conventional high temperature process. The optimal temperature of synthesis, the absorption spectrum and the luminescent properties of the glasses were studied. The fluorescence spectrum of Sm^3+ was observed in CaO-SiO2-B2O3 : Sm2O3 glasses. The fluorescence spectrum of the sample has three major emission bands peaking at 568, 605 and 650 nm respectively. The strongest emission band peak at 605 nm. It is concluded that the emissions were caused by the f-f transition of the 4f electrons of Sm^3+. The emission bands peaking at 568, 604 and 650 nm correspond to the ^4G5/2→^6H5/2 transition, ^4G5/2→^6H7/2 transition and ^4G5/2→^6H9/2 trasition respectively. The luminescent properties of CaO-SiO2-B2O3 glasses indicate that the glass can convert the ultraviolet in the sunlight into red light, thus increasing the intensity of red light. The luminescent properties of these glasses may be used to make kinds of light-conversion glass for agriculture.展开更多
文摘Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of montmorillonite (MT) by ion exchange and coordination reaction of L with the Tb^3+ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL (NO3) ]^2+-MT and [TbL]^3+-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing (d001) approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.
基金financial supportfrom PRAMX 98-05 and helpful discussion with Dr.A.C.Franville.
文摘Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
基金Science and Technology Development Fund (Shanghai ,0752nm008 ,JY601)
文摘A novel rare earth luminescent material La2O2CO3 was synthesized successfully by sintering the mixture of La2(CO3)3 and KCl powders. The XRD results revealed that the additive KCl not only affected the crystal form and crystallinity of the final product, but also greatly promoted its luminescence, compared with the products without adding KCl. The as-prepared material showed a strong green emission band centered at 470 nm under the excitation of 325 nm. Our experimental results indicated that the crystal form of La2O2CO3 affected its luminescent properties significantly. According to the primary analysis, the green emission might be related to the oxygen vacancies in La2O2CO3 lattice.
基金This work was supported by Ministry of Science and Technology funded by the Taiwan Government[Grant No.MOST 105-2622-E-327-011-CC3]However,the publication of our work is fully in MOST’s favor.
文摘Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth luminescent materials were used owing to their active light emission and reusability.Additionally,solar lightemitting diode lights and car-light reflection were utilised to increase the recognition and reliability of reflective cat eyes.Along with carbon reduction,this can save energy and enhance road safety.This study considered the Theory of Inventive Problem Solving and a literature review to analyse the issues in existing products.Then,expert interviews were conducted to screen projects and develop product design policies.Finally,the ratio of light-storage materials was experimentally determined and the prototypes implemented.This cat’s eye addresses the shortcomings identified in previous analyses of existing products.We applied energy storage environmental protection materials,together with material proportioning(which balanced warning efficiency against cost-effectiveness)to develop diversified modular kits;these were flexible in terms of quantity and easily assembled.This study achieved four key objectives:(1)reducing the research and development costs of the manufacturer;(2)offering buyers a diverse suite of products;(3)responding to a need to improve diverse road user safety;and(4)reducing government procurement costs for safety warning products.The results provide a reference for the creative modular design of energy-saving products for public road safety planning in various industries.
文摘Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.
基金supported by the 2019-2021 Undergraduate Teaching Project of Chengdu University of Information Technology(BKJX2020022,BKJX2020081)Department of Human Resources and Social Security of Sichuan Province(2019Z226).
文摘Due to the outbreak of |x-19,colleges and universities have actively responded to the call of the state to carry out online teaching in completing their teaching tasks.After the epidemic,the online and offline hybrid teaching has become a novel mode of teaching which meets the requirements of teaching reform and the information society.This teaching method integrates both the online and offline teaching which plays an important role in enhancing teaching qualities and learning experiences.However,due to the lack of experience,there are some issues occurring in the teaching process of this method.The Luminescent Materials and Applications course is used as the subject in this article.The difficulties in traditional offline teaching as well as the advantages,detailed course construction process,and effectiveness evaluation of hybrid teaching are summarized and meticulously analyzed.In regard to that,the application of the online and offline hybrid teaching in the Luminescent Materials and Applications course is beneficial to the learning of professional knowledge and the cultivation of students'scientific literacy.Therefore,it is an effective way to improve and enrich this course by using the online and offline hybrid teaching method.
文摘Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.
基金the National Natural Science Foundations of China (No50372006 and No20273007)
文摘A new method was reported for surface modification of an up-conversion luminescence material with hydrosulfide group. The factors that may influence the surface modification,such as reaction time,amount of catalyzer and modifier,and reaction solvent,were investigated. The optimal conditions were that the reaction time,the quantity of the basic catalyzer,the quantity of modifier and the volume of reaction solvent were 40 min,1.0,1.0,and 40 mL,respectively. The results indicated that hydrosulfide group content modified on the surface of up-conversion luminescence material reached to 0.1430 mmol/g,and this modified up-conversion luminescence material could be widely used in the study of structure of protein and the property of microenvironment.
基金supported by the Department of Industry and Information Technology of Gansu Province and Baotou Rare Earth Research Institute。
文摘Persistent luminescence (PersL) materials,as environmentally friendly and energy-saving materials,have broad application prospects in many fields such as lighting,chemistry and even biomedicine.However,studies on the types,performances and mechanism of PersL materials are still insufficient,which significantly restricts their development and application.Under this consideration,we successfully synthesized a yellow PersL material CaSrGa_(4)O_(8)(CSG).The crystal structure was studied in detail through Rotation Electron Diffraction (RED) and Powder X-ray Diffraction (PXRD).What’s more,by co-doping Mn^(2+) and Yb^(3+),the afterglow brightness of CSG could be increased by nearly 20 times,and the afterglow duration could reach more than 6 h.It is worth mentioning that the samples also have excellent performances in mechanical luminescence (ML),photostimulated luminescence (PSL) and cathodoluminescence (CL),which was also investigated systematically.Finally,an anti-counterfeiting label was designed by the samples to reveal the potential of their application in anti-counterfeiting.The results showed that our research not only provided a new candidate PersL material for multifunctional applications,but also gave good help for studying the physical and chemical properties of CSG.
文摘The combinatorial material chip approach is an excellent innovation for inorganic functional material research, and it can discover and screen new materials efficiently. In the present work, the approach was used to find quickly and improve gadolinium aluminate phosphors (Gd_ 1-xAl_yO_z∶RE_x). Under UV lamp excited (λ_ ex=254 nm) the Gd_ 1-xAl_yO_z∶RE_x phosphor material chip evaluation shows that the suitable n(Al)∶n(Gd) in host materials is 1∶1 for Eu and Tb ion activators. The luminescence character coherence between combinatorial material chip and parallelism powder samples produced by nitric-citric process was also confirmed.
基金This work was financially supported by the National Natural Science Foundation of China (Nos.50372006 and 20273007).
文摘Surface modification of up-conversion luminescence materials (Na[Y0.57Yb0.39Er0.04]F4 modified by amino groups) by grafting and modifying with aldehyde groups was studied by means of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and emission spectrum (EM). The surface modification effect was compared using two different finishhag agents, p-phthalaldehyde and glutaraldehyde. It was found that the surface of up-conversion luminescence materials could be modified by aldehyde groups of the two finishing agents, the systematic dispersibility and the thermostability of the up-conversion luminescence material modified by p-phthalaldehyde were better than those of the material modified by glutaraldehyde, and the luminous intensity of the material modified by p-phthalaldehyde was increased. The AI (the ratio of the suspended segmental quality in the specimen to the total mass of the specimen) of the material modified by p-phthalaldehyde was higher than that of the material modified by glutaraldehyde. It is obviously seen that the embellishment effect of p-phthalaldehyde as a finishing agent was better than that of glutaraldehyde. In addition, the reasons why p-phthalaldehyde is a good finishing agent are also explained.
文摘Progress of studies on various multi-color long afterglow luminescence materials was reviewed.Two luminescent mechanism of long afterglow behavior were discussed.Further research and development prospects about the materials were proposed.
文摘The polycrystalline Sr_9Ca(PO_4)_6Cl_2:Eu has been synthesized by solid state reaction.The reaction condition,the appropriate raw materials and their quantity used,which may affect the photostimulable luminescence (PSL),have been systematically inves- tigated.The properties of this PSL phosphor as a material for storing and reproducing the X-ray image in computer-aided radiography have been reported briefly.
文摘The study on the effects of SrO/Al 2O 3 molar ratio on the crystalline phases and photoluminescence characteristics of strontium aluminate phosphors co-activated with Eu 2+ and Dy 3+ were conducted by X-ray powder diffractometry, fluorescence spectrometer and photometer. The strontium aluminate luminescent materials with different SrO/Al 2O 3 molar ratio emit the visible lights with different color tone after removal of excitation. The peak wavelengths of the emission spectra drift in the direction of short wave, the quantity of Sr 4Al 14O 25 crystalline phase increases and the afterglow time lengthens with the SrO/Al 2O 3 reduction. The results show that when the SrO/Al 2O 3 molar ratio is near 1, the photoluminescence materials have high luminescent intensity, and when it is near 0.75, they have long afterglow time. However, when SrO/Al 2O 3 molar ratio is more than 1, the luminescent materials appear strong alkaline in water solution; when SrO/Al 2O 3 molar ratio is much less than 0.75, the samples need a higher temperature to be sintered.
文摘Long afterglow phosphors MAl2O4:Eu^2+ , Dy^3+ (M = Ca, Sr, Ba) were synthesized by microemulsion method, and their crystal structure and luminescent properties were compared and investigated. XRD patterns of samples indicate that phosphors CaAl2O4:Eu^2+, Dy^3+ and SrAl2O4 : Eu^2+, Dy^3+ are with monoelinie crystal structure and phosphor BaAl2O4:Eu^2+ , Dy^3+ is with hexagonal crystal structure. The wide range of excitation spectrum of phosphors MAl2O4: Eu^2 + , Dy^3+ (M = Ca,Sr, Ba) indicates that the luminescent materials can he excited by light from ultraviolet ray to visible light and the maximum emission wavelength of phosphors MAl2O4:Eu^2+ , Dy^3+ (M = Ca, Sr, Ba) is found mainly at λem of 440 nm (M = Ca), 520 nm (M = Sr) and 496 nm (M = Ba) respectively, the corresponding colors of emission light are blue, green and eyna-green respectively. The afterglow decay tendency of phosphors can he summarized as three processes: initial rapid decay, intermediate transitional decay and very long slow decay. Afterglow decay curves coincide with formula I = At^ - n, and the sequence of afterglow intensity and time is Sr 〉 Ca 〉 Ba.
基金the National Natural Science Foundation of China(Grant Nos.11975220,51972291,11575170,and 11605194)。
文摘The translucent GGAG:Ce/glass composites are prepared successfully by ball-milling,tableting,and pressureless sintering.The thickness of composites is about 400μm.The x-ray diffraction(XRD),differential scanning calorimetry(DSC),density of composite materials are measured and discussed systematically.The scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS)elemental mapping are employed to analyze the particle size,the shape of powders,and the distribution of GGAG:Ce particles in the glass matrix,respectively.The decay time,ultraviolet,(UV),x-ray excitation luminescence spectra,and temperature spectra are studied.The results show that the composite materials have high light output,good thermostability,and short decay time.The method adopted in this work is an effective method to reduce the preparation time and cost of the sample.The ultralow afterglow indicates that the composite materials have an opportunity to be used for x-ray detection and imaging.
文摘Precursor of SrAl_2O_4∶Eu, Dy phosphor was prepared by co-precipitation method, in which dispersing agent was added to control particle size. Microwave radiation method was used to synthesize SrAl_2O_4∶Eu, Dy phosphors. Experimental results show that the precursor was composed of crystalline ammonium dawsonite hydrate and strontium carbonate, and the adding of dispersing agent can effectively diminish precursor size. The precursor can be transformed to pure SrAl_2O_4 phase after being calcined for 40 min in microwave chamber. The phosphors possess good persistent luminescent properties, finer grain size ranged from 0.2 μm to 5 μm and better size distribution than that of solid-state reaction. The doping of B^(3+) will result in the increasing of crystallite size, but can effectively improve phosphors′ persistent luminescent properties.
基金Supported by the National High-Tech Research and Development Program of China(No.2008AA03A315)the Natural Science Foundation of Tianjin City,China(No.08JCZDJC16900)
文摘Blue luminescent compounds T1―T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1 H NMR,13 C NMR and high resolution mass spectrometry(HRMS).Four compounds T1―T4 exhibit excellent solubility in common solvents and good film forming properties.Quantum chemical calculations show that compounds T1―T4 have asymmetric linear structures and the proper highest occupied molecular orbital(HOMO) levels.The UV-Vis absorption and fluorescence emission spectra of the four compounds in dilute chloroform solutions and on the solid films were measured.It reveals that compounds T1―T4 exhibit similar spectral behavior,suggesting that these compounds can form amorphous state in solid films.The calculated absorption and emission spectra of compounds T1―T4 are in good agreement with experimentally determined ones.Compounds T1―T4 have absolute fluorescence quantum yield above 17% in dilute chloroform solutions.Four compounds possess high glass-transition temperature(T g) exceeding 97 ℃ and the maximum T g is 155.28 ℃ for compound T3.Cyclic voltammetry measurements show that these compounds have proper HOMO levels in a range of-5.01―-5.13 eV for hole injection.The properties of compounds T1―T4 indicate that these compounds are candidates for the application in organic light-emitting devices(OLEDs) as hole-transporting materials(HTMs).
文摘CaO-SiO2-B2O3 :Sm2O3 glasses were synthesized in air atmosphere with conventional high temperature process. The optimal temperature of synthesis, the absorption spectrum and the luminescent properties of the glasses were studied. The fluorescence spectrum of Sm^3+ was observed in CaO-SiO2-B2O3 : Sm2O3 glasses. The fluorescence spectrum of the sample has three major emission bands peaking at 568, 605 and 650 nm respectively. The strongest emission band peak at 605 nm. It is concluded that the emissions were caused by the f-f transition of the 4f electrons of Sm^3+. The emission bands peaking at 568, 604 and 650 nm correspond to the ^4G5/2→^6H5/2 transition, ^4G5/2→^6H7/2 transition and ^4G5/2→^6H9/2 trasition respectively. The luminescent properties of CaO-SiO2-B2O3 glasses indicate that the glass can convert the ultraviolet in the sunlight into red light, thus increasing the intensity of red light. The luminescent properties of these glasses may be used to make kinds of light-conversion glass for agriculture.