Fluorescence imaging in the second near-infrared window(NIR-II,900–1880 nm)with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imagi...Fluorescence imaging in the second near-infrared window(NIR-II,900–1880 nm)with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution.However,the traditional NIR-IIfluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal e±ciency,as well as di±cultly to adjust.Two types of upgraded NIR-IIfluorescence confocal microscopes,sharing the same pinhole by excitation and emission focus,leading to higher confocal e±ciency,are built in this work.One type is-ber-pinhole-based confocal microscope applicable to CW laser excitation.It is constructed forfluorescence intensity imaging with large depth,high stabilization and low cost,which could replace multiphotonfluorescence microscopy in some applications(e.g.,cerebrovascular and hepatocellular imaging).The other type is air-pinhole-based confocal microscope applicable to femtosecond(fs)laser excitation.It can be employed not only for NIR-IIfluorescence intensity imaging,but also for multi-channelfluorescence lifetime imaging to recognize different structures with similarfluorescence spectrum.Moreover,it can be facilely combined with multiphotonfluorescence microscopy.A single fs pulsed laser is utilized to achieve up-conversion(visible multiphotonfluorescence)and down-conversion(NIR-II one-photonfluorescence)excitation simultaneously,extending imaging spectral channels,and thus facilitates multi-structure and multi-functional observation.展开更多
Conventional color-printing systems often use inks of three hues, such as CMY, CMYK and CMYKLcLm, but in order to obtain more realistic color reproductions, the ink set of more than three hues has been adopted by some...Conventional color-printing systems often use inks of three hues, such as CMY, CMYK and CMYKLcLm, but in order to obtain more realistic color reproductions, the ink set of more than three hues has been adopted by some color-printing systems. It is difficult, however, to model the composed color with the multiple inks when the number of the output ink hues exceeds three due to the none-unique mapping between the color spaces of the CIE Lab and the multi-color printing device. In this paper, we propose a fine color-printing method for multi-color printing device with the ink set of more than three hues. The proposed approach has good color expression ability and provides fine control of the printed color. By dividing the output color space into several subspaces, our method allows one-to-one mapping between the standard color space and the multi-color output color space. It has been proved effective when applied to the digital inkjet printer—Mutoh8000.展开更多
Carbon dots(CDs)with aggregation-induced emission(AIE)have sparked significant interest in multidimensional anti-counterfeiting due to their exceptional fluorescence properties.However,the preparation of AIE CDs with ...Carbon dots(CDs)with aggregation-induced emission(AIE)have sparked significant interest in multidimensional anti-counterfeiting due to their exceptional fluorescence properties.However,the preparation of AIE CDs with multicolor solid-state fluorescence remains a formidable challenge due to its complicated construction.In the present work,a novel class of multicolor AIE CDs(M-CDs)were fabricated using selected precursor(salicylic acid,thiosalicylic acid,and 2,2'-dithiodibenzoic acid),with an eco-friendly,low-cost one-pot solvothermal method.In the dilute organic solution,M-CDs manifested blue emission,but upon aggregation in the presence of water,the red,yellow,green,and blue emissions were displayed due to the AIE effect.Structural analysis,coupled with theoretical calculations,revealed that the increase in the size of sp2 domains would lower the Eg and cause a red-shift emission wavelength.Significantly,the continuous emission of M-CDs from blue to red can be utilized as ink for multimode printing,enabling the creation of a variety of school badges and quick response codes.These findings hold promising implications for multi-information encryption applications.展开更多
To identify alien chromosomes in recipient progenies and to analyze genome components in polyploidy, a genomic in situ hybridization （GISH） technique that is suitable for cotton was developed using increased stringe...To identify alien chromosomes in recipient progenies and to analyze genome components in polyploidy, a genomic in situ hybridization （GISH） technique that is suitable for cotton was developed using increased stringency conditions. The increased stringency conditions were a combination of the four factors in the following optimized state： 100：1 ratio of blocking DNA to probe, 60% formamide wash solution, 43 ℃ temperature wash and a 13 min wash. Under these specific conditions using gDNA from Gossypium sturtianum （C1 C1 ） as a probe, strong hybridization signals were only observed on chromosomes from the C1 genome in somatic cells of the hybrid F1 （G. hirsutum x G. sturtianum） （AtDtC1）. Therefore, GISH was able to discriminate parental chromosomes in the hybrid. Further, we developed a multi-color GISH to simultaneously discriminate the three genomes of the above hybrid. The results repeatedly displayed the three genomes, At, Dt, and C1, and each set of chromosomes with a unique color, making them easy to identify. The power of the multi-color GISH was proven by analysis of the hexaploid hybrid F1 （G. hirsutum x G. australe） （AtAtDtDtG2G2）. We believe that the powerful multi-color GISH technique could be applied extensively to analyze the genome component in polyploidy and to identify alien chromosomes in the recipient progenies.展开更多
Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing...Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing smart fluorescent materials.Herein,a color-tunable supramolecular emissive system was developed based on cucurbit[8]uril mediated host-guest assembly.Chemical designing for the molecular structures with minimized change resulted in different assembly modes and hence generating distinctive fluorescence,including green,yellow and orange with the addition of cucurbit[n]uril.Taking advantage of this feature,the advanced information encryption material(4D code)with multiple encryption levels and time-dependent encryption feature was developed.Such a code was dynamic on time scale,generating a series of 3D codes with time.The encrypted information only can be recognized by integrating time-coursed codes.This work provides a new insight for designing intelligent fluorescent materials for information encryption with high level of security.展开更多
Frequency conversion based on three-wave mixing is a critical nonlinear optic application,extending the frequency range of existing lasers and realizing frequency-transduced detectors in a wavelength range that lacks ...Frequency conversion based on three-wave mixing is a critical nonlinear optic application,extending the frequency range of existing lasers and realizing frequency-transduced detectors in a wavelength range that lacks an effective detector.Phase matching is vital for effective frequency conversion.The advantages of quasi-phase matching(QPM)over birefringent phase matching are a lack of walk-off effect,a maximum nonlinear coefficient,and phase matching in the entire transparency window.Herein,using different types and orders of QPM,four kinds of effective frequency doubling processes are realized in a periodically poled potassium titanyl phosphate(KTP)crystal with a single period,and three kinds of frequency doubling processes are experimentally verified.We also show a feasible way to construct an RGB color generator based on two different QPM processes.This study significantly expands the feasible frequency conversion of existing lasers to different wavelengths,providing an effective method for multi-color laser generation based on periodically poled KTP crystals.展开更多
Mechano-luminescence(ML) has been found diverse applications such as stress sensing,3-D signature,energy harvesting,and anti-counterfeiting,due to the unique properties of the corresponding ML phosphors performing in-...Mechano-luminescence(ML) has been found diverse applications such as stress sensing,3-D signature,energy harvesting,and anti-counterfeiting,due to the unique properties of the corresponding ML phosphors performing in-situ and real-time response to mechanical stimulus.Trap-controlled ML materials realize reproducible,quantitative mechano-optical conversion resulting from the released carriers for the trap-mediated charge storage and release.Herein,modulating traps matters the controllable ML behavior for their promising applications.In this work,a deep trap distributed ranging from 0.9 to 1,3 eV is realized consecutively for the introduction of Sm^(3+)ions into LaGaO_(3) matrix,which contributes to the red emission at 600 nm under mechanical stimuli.Moreover,tunable ML emission modulated from 600to 545 nm is successfully achieved for the codopant of Tb^(3+)ions.It is unambiguously indicated that the released carriers from the trap sharing rather than an additional constructed trap contribute to the modulated ML color.Accordingly,multi-mode anti-counterfeiting and encryption are achieved with the as-explored Sm^(3+),Tb^(3+)co-activated ML phosphor.展开更多
This paper presents Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B, V and R filters by using the Nanshan 1 m telescope administered by ...This paper presents Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B, V and R filters by using the Nanshan 1 m telescope administered by Xinjiang Astronomical Observatory. 19 variable stars and three variable candi- dates were detected in a 45＇ - 48.75＇ field around the cluster. 12 of the variable stars are newly-discovered variable objects. The physical properties, classifications and memberships of these 22 objects are studied through their light curves, their positions on the color-magnitude diagram and with archival data from the Naval Observatory Merged Astrometric Dataset. Among these objects, five are eclipsing binary systems, six are pulsating variable stars including one known 6 Scuti star and one newly-discovered RR Lyrae star. The distance to the RR Lyrae star is estimated to be 7.9 - 0.3 kpc, indicating that the star is located far behind the cluster. Four variable stars are probable members of the cluster, and 13 of the 22 objects are confirmed to be field stars.展开更多
We study theoretically intense terahertz radiation from multi-color laser pulse with uncommon frequency ratios. Com- paring the two-color laser scheme, of which the uncommon frequency ratio should be set to be a speci...We study theoretically intense terahertz radiation from multi-color laser pulse with uncommon frequency ratios. Com- paring the two-color laser scheme, of which the uncommon frequency ratio should be set to be a specific value, we show that by using multi-color harmonic laser pulses as the first pump component, the lasers as the second pump component can be adjusted in a continuous frequency range. Moreover, these multi-color laser pulses can effectively modulate and enhance the terahertz radiation, and the terahertz yield increases with the increase of the wavelength of the uncommon pump com- ponent and is stable to the laser relative phase. Finally, we utilize the electron densities and velocities of ionization events to illustrate the physical mechanism of the intense terahertz generation.展开更多
Acenes with linearly fused benzene rings have attracted much attention due to their intriguing optical and electronic properties.Nevertheless,the poor ambient stability of longer acenes has hampered the investigation ...Acenes with linearly fused benzene rings have attracted much attention due to their intriguing optical and electronic properties.Nevertheless,the poor ambient stability of longer acenes has hampered the investigation of their physicochemical properties and potential applications.The incorporation of main group elements into the acene backbones provides a viable strategy to enhance the stability,and meanwhile,generates a new family of heteroatom-doped acenes(namely heteroacenes)with modified properties and functions.In particular,boron-containing acenes represent an attractive class of heteroacenes owing to the existence of vacant p orbital of boron,which endows theπ-conjugated systems with appealing features,such as Lewis acidity,electron-accepting capability,stimuli-responsivity,and adjustable photophysical properties.During the past decade,significant progress has been achieved in the synthesis and applications of boron-containing acenes,but a focused review on this topic has been elusive.Here,we summarize the recent advances in the studies on boron-containing acenes,covering their synthesis,intriguing properties,and various applications in electroluminescence and electronic devices,as well as in biosensors,etc.We hope that this timely review will stimulate new research interest in this unique family of materials and promote their optoelectronic applications.展开更多
Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluor...Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluorescent properties,feeding silkworms with fluorescent additives is facile,low-cost and environment friendly,which has the prospect of large-scale production.In this paper,we reviewed the research progress for this aim in the past ten years,and summarized the unified characteristics for the substances that can enter the silk gland by digestive tract of silkworms.The advantages and disadvantages of various fluorescent materials for this application are compared in detail.And the future research directions are suggested to overcome the shortcomings of the present research.展开更多
In an automatic bobbin management system that simultaneously detects bobbin color and residual yarn,a composite texture segmentation and recognition operation based on an odd partial Gabor filter and multi-color space...In an automatic bobbin management system that simultaneously detects bobbin color and residual yarn,a composite texture segmentation and recognition operation based on an odd partial Gabor filter and multi-color space hierarchical clustering are proposed.Firstly,the parameter-optimized odd partial Gabor filter is used to distinguish bobbin and yarn texture,to explore Garbor parameters for yarn bobbins,and to accurately discriminate frequency characteristics of yarns and texture.Secondly,multi-color clustering segmentation using color spaces such as red,green,blue(RGB)and CIELUV(LUV)solves the problems of over-segmentation and segmentation errors,which are caused by the difficulty of accurately representing the complex and variable color information of yarns in a single-color space and the low contrast between the target and background.Finally,the segmented bobbin is combined with the odd partial Gabor’s edge recognition operator to further distinguish bobbin texture from yarn texture and locate the position and size of the residual yarn.Experimental results show that the method is robust in identifying complex texture,damaged and dyed bobbins,and multi-color yarns.Residual yarn identification can distinguish texture features and residual yarns well and it can be transferred to the detection and differentiation of complex texture,which is significantly better than traditional methods.展开更多
Multi-color luminescence basing on amorphous Eu^3＋/Tb^3＋ co-doped Zn-A1 hydroxides and their annealed samples were studied in detail. Results suggest that excellent red emissions due to E^u3＋ and green emissions at...Multi-color luminescence basing on amorphous Eu^3＋/Tb^3＋ co-doped Zn-A1 hydroxides and their annealed samples were studied in detail. Results suggest that excellent red emissions due to E^u3＋ and green emissions attributed to Tb^3＋ appear under the excitation of favorable wavelength for all the as- prepared amorphous samples. Moreover, the emission intensity depends on the Eu^3＋/Tb^3＋ molar ratio. The samples annealed at 300, 500, and 700 ℃ still exhibit amorphous state, and multi-color lumi- nescence kept in the samples annealed at 300 ℃, while luminescence quenched for the samples annealed at 500 and 700 ℃. However, a broad emission ranging from 450 to 650 nm occurs in some samples annealed at 900 ℃. Further, the fluorescence decay and lifetimes for the as-prepared samples and the samples annealed at 300℃ were investigated. It is found that all the decay curves of emissions due to Tb^3＋ and Eu^3＋ present characteristic double exponential function despite their different lifetimes. The present work may be a good example for developing new multi-color even white light emitting materials.展开更多
Electrochemiluminescence(ECL),also called electrogenerated chemiluminescence,is luminescence that is produced by chemical reactions triggered by electrochemical method.ECL imaging is a novel imaging technique,which ca...Electrochemiluminescence(ECL),also called electrogenerated chemiluminescence,is luminescence that is produced by chemical reactions triggered by electrochemical method.ECL imaging is a novel imaging technique,which can simultaneously provide two kinds of signals of both electrochemistry and optical image.Over the past two decades,ECL imaging has been not only a powerful tool for investigating the fundamental scientific questions such as ECL mechanisms and reaction kinetics,but also a versatile analytical technique for detection of a wide range of analytes including small molecules,DNA,proteins,and cells.In the first part of this review,we briefly describe the reaction mechanisms of ECL generation.Then the review focuses on the research progress on the ECL imaging approach.It is basically introduced from the following five aspects:(i)visualization of electroactive sites on surfaces,(ii)imaging analysis at the single-bead and single-cell levels,(iii)array bioanalysis,(iv)multi-color ECL imaging,and(v)paper chip based on ECL imaging.Finally,some perspectives and future directions in this active research area are presented.展开更多
基金supported by National Natural Science Foundation of China(61975172,82001874 and 61735016).
文摘Fluorescence imaging in the second near-infrared window(NIR-II,900–1880 nm)with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution.However,the traditional NIR-IIfluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal e±ciency,as well as di±cultly to adjust.Two types of upgraded NIR-IIfluorescence confocal microscopes,sharing the same pinhole by excitation and emission focus,leading to higher confocal e±ciency,are built in this work.One type is-ber-pinhole-based confocal microscope applicable to CW laser excitation.It is constructed forfluorescence intensity imaging with large depth,high stabilization and low cost,which could replace multiphotonfluorescence microscopy in some applications(e.g.,cerebrovascular and hepatocellular imaging).The other type is air-pinhole-based confocal microscope applicable to femtosecond(fs)laser excitation.It can be employed not only for NIR-IIfluorescence intensity imaging,but also for multi-channelfluorescence lifetime imaging to recognize different structures with similarfluorescence spectrum.Moreover,it can be facilely combined with multiphotonfluorescence microscopy.A single fs pulsed laser is utilized to achieve up-conversion(visible multiphotonfluorescence)and down-conversion(NIR-II one-photonfluorescence)excitation simultaneously,extending imaging spectral channels,and thus facilitates multi-structure and multi-functional observation.
基金Project (No. M603034) supported by the Natural Science Foundationof Zhejiang Province, China
文摘Conventional color-printing systems often use inks of three hues, such as CMY, CMYK and CMYKLcLm, but in order to obtain more realistic color reproductions, the ink set of more than three hues has been adopted by some color-printing systems. It is difficult, however, to model the composed color with the multiple inks when the number of the output ink hues exceeds three due to the none-unique mapping between the color spaces of the CIE Lab and the multi-color printing device. In this paper, we propose a fine color-printing method for multi-color printing device with the ink set of more than three hues. The proposed approach has good color expression ability and provides fine control of the printed color. By dividing the output color space into several subspaces, our method allows one-to-one mapping between the standard color space and the multi-color output color space. It has been proved effective when applied to the digital inkjet printer—Mutoh8000.
基金the National Natural Science Foundation of China(No.21807085)the Natural Science Foundation Research Project of Shaanxi Province(No.2023-JCYB-087)+2 种基金the Technology Innovation Leading Program of Shaanxi(No.2020QFY07-05)the Innovation Capability Support Program of Shaanxi(No.2022KJXX-88)the fund of Education Department of Shaanxi Province(Program No.Z20230071).
文摘Carbon dots(CDs)with aggregation-induced emission(AIE)have sparked significant interest in multidimensional anti-counterfeiting due to their exceptional fluorescence properties.However,the preparation of AIE CDs with multicolor solid-state fluorescence remains a formidable challenge due to its complicated construction.In the present work,a novel class of multicolor AIE CDs(M-CDs)were fabricated using selected precursor(salicylic acid,thiosalicylic acid,and 2,2'-dithiodibenzoic acid),with an eco-friendly,low-cost one-pot solvothermal method.In the dilute organic solution,M-CDs manifested blue emission,but upon aggregation in the presence of water,the red,yellow,green,and blue emissions were displayed due to the AIE effect.Structural analysis,coupled with theoretical calculations,revealed that the increase in the size of sp2 domains would lower the Eg and cause a red-shift emission wavelength.Significantly,the continuous emission of M-CDs from blue to red can be utilized as ink for multimode printing,enabling the creation of a variety of school badges and quick response codes.These findings hold promising implications for multi-information encryption applications.
基金the National Natural Science Foundation of China (30571184)Jiangsu Provincial Natural Science Foundation (BK2007166)+3 种基金the Tenth Five-year Plan of the National Key Program (2004BA525B05)the 111 Project(B08025) the Eleventh Five-year Plan of the National Sci-technologicalSupporting Program (2006BAD13B04-1-08)the Changjiang Scholars and Innovative Research Team in University and the Teaching and Research AwardProgram for Outstanding Young Teachers in Higher Education Institutions ofMinistry of Education (MOE), China.
文摘To identify alien chromosomes in recipient progenies and to analyze genome components in polyploidy, a genomic in situ hybridization （GISH） technique that is suitable for cotton was developed using increased stringency conditions. The increased stringency conditions were a combination of the four factors in the following optimized state： 100：1 ratio of blocking DNA to probe, 60% formamide wash solution, 43 ℃ temperature wash and a 13 min wash. Under these specific conditions using gDNA from Gossypium sturtianum （C1 C1 ） as a probe, strong hybridization signals were only observed on chromosomes from the C1 genome in somatic cells of the hybrid F1 （G. hirsutum x G. sturtianum） （AtDtC1）. Therefore, GISH was able to discriminate parental chromosomes in the hybrid. Further, we developed a multi-color GISH to simultaneously discriminate the three genomes of the above hybrid. The results repeatedly displayed the three genomes, At, Dt, and C1, and each set of chromosomes with a unique color, making them easy to identify. The power of the multi-color GISH was proven by analysis of the hexaploid hybrid F1 （G. hirsutum x G. australe） （AtAtDtDtG2G2）. We believe that the powerful multi-color GISH technique could be applied extensively to analyze the genome component in polyploidy and to identify alien chromosomes in the recipient progenies.
基金supported by the National Natural Science Foundation of China(22025503,22220102004)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX03)+3 种基金the Fundamental Research Funds for the Central Universitiesthe Programme of Introducing Talents of Discipline to Universities(B16017)the Science and Technology Commission of Shanghai Municipality(21JC1401700)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(SN-ZJU-SIAS-006)。
文摘Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing smart fluorescent materials.Herein,a color-tunable supramolecular emissive system was developed based on cucurbit[8]uril mediated host-guest assembly.Chemical designing for the molecular structures with minimized change resulted in different assembly modes and hence generating distinctive fluorescence,including green,yellow and orange with the addition of cucurbit[n]uril.Taking advantage of this feature,the advanced information encryption material(4D code)with multiple encryption levels and time-dependent encryption feature was developed.Such a code was dynamic on time scale,generating a series of 3D codes with time.The encrypted information only can be recognized by integrating time-coursed codes.This work provides a new insight for designing intelligent fluorescent materials for information encryption with high level of security.
基金supported by the National Natural Science Foundation of China(Nos.92065101 and 11934013)the Space Debris Research Project of China(No.KJSP2020020202)。
文摘Frequency conversion based on three-wave mixing is a critical nonlinear optic application,extending the frequency range of existing lasers and realizing frequency-transduced detectors in a wavelength range that lacks an effective detector.Phase matching is vital for effective frequency conversion.The advantages of quasi-phase matching(QPM)over birefringent phase matching are a lack of walk-off effect,a maximum nonlinear coefficient,and phase matching in the entire transparency window.Herein,using different types and orders of QPM,four kinds of effective frequency doubling processes are realized in a periodically poled potassium titanyl phosphate(KTP)crystal with a single period,and three kinds of frequency doubling processes are experimentally verified.We also show a feasible way to construct an RGB color generator based on two different QPM processes.This study significantly expands the feasible frequency conversion of existing lasers to different wavelengths,providing an effective method for multi-color laser generation based on periodically poled KTP crystals.
基金Project supported by the Yunnan Provincial Natural Science Foundation (202101AT070126)the Research Start-up Fund of Chengdu University of Technology (10912-KYQD2020-08476)+1 种基金Fund of Hubei Key Laboratory of Plasma Chemistry,Advanced Materials (KF202103)Sichuan Natural Science Foundation (2022YFH0108,2022JDJQ0030)。
文摘Mechano-luminescence(ML) has been found diverse applications such as stress sensing,3-D signature,energy harvesting,and anti-counterfeiting,due to the unique properties of the corresponding ML phosphors performing in-situ and real-time response to mechanical stimulus.Trap-controlled ML materials realize reproducible,quantitative mechano-optical conversion resulting from the released carriers for the trap-mediated charge storage and release.Herein,modulating traps matters the controllable ML behavior for their promising applications.In this work,a deep trap distributed ranging from 0.9 to 1,3 eV is realized consecutively for the introduction of Sm^(3+)ions into LaGaO_(3) matrix,which contributes to the red emission at 600 nm under mechanical stimuli.Moreover,tunable ML emission modulated from 600to 545 nm is successfully achieved for the codopant of Tb^(3+)ions.It is unambiguously indicated that the released carriers from the trap sharing rather than an additional constructed trap contribute to the modulated ML color.Accordingly,multi-mode anti-counterfeiting and encryption are achieved with the as-explored Sm^(3+),Tb^(3+)co-activated ML phosphor.
基金supported by the National Natural Science Foundation of China under Grant No.11273051the program of Light in China Western Region(LCWR,Grant Nos.XBBS201221 and 2015-XBQN-A-02)
文摘This paper presents Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B, V and R filters by using the Nanshan 1 m telescope administered by Xinjiang Astronomical Observatory. 19 variable stars and three variable candi- dates were detected in a 45＇ - 48.75＇ field around the cluster. 12 of the variable stars are newly-discovered variable objects. The physical properties, classifications and memberships of these 22 objects are studied through their light curves, their positions on the color-magnitude diagram and with archival data from the Naval Observatory Merged Astrometric Dataset. Among these objects, five are eclipsing binary systems, six are pulsating variable stars including one known 6 Scuti star and one newly-discovered RR Lyrae star. The distance to the RR Lyrae star is estimated to be 7.9 - 0.3 kpc, indicating that the star is located far behind the cluster. Four variable stars are probable members of the cluster, and 13 of the 22 objects are confirmed to be field stars.
基金Project supported by the National Natural Science Foundation of China(Grant No.11604205)the Talent Program of Shanghai University of Engineering Science,China
文摘We study theoretically intense terahertz radiation from multi-color laser pulse with uncommon frequency ratios. Com- paring the two-color laser scheme, of which the uncommon frequency ratio should be set to be a specific value, we show that by using multi-color harmonic laser pulses as the first pump component, the lasers as the second pump component can be adjusted in a continuous frequency range. Moreover, these multi-color laser pulses can effectively modulate and enhance the terahertz radiation, and the terahertz yield increases with the increase of the wavelength of the uncommon pump com- ponent and is stable to the laser relative phase. Finally, we utilize the electron densities and velocities of ionization events to illustrate the physical mechanism of the intense terahertz generation.
基金financial support from the National Natural Science Foundation of China(Nos.92256304 and 22071120)the National Key R&D Program of China(2020YFA0711500)the Fundamental Research Funds for the Central Universities.
文摘Acenes with linearly fused benzene rings have attracted much attention due to their intriguing optical and electronic properties.Nevertheless,the poor ambient stability of longer acenes has hampered the investigation of their physicochemical properties and potential applications.The incorporation of main group elements into the acene backbones provides a viable strategy to enhance the stability,and meanwhile,generates a new family of heteroatom-doped acenes(namely heteroacenes)with modified properties and functions.In particular,boron-containing acenes represent an attractive class of heteroacenes owing to the existence of vacant p orbital of boron,which endows theπ-conjugated systems with appealing features,such as Lewis acidity,electron-accepting capability,stimuli-responsivity,and adjustable photophysical properties.During the past decade,significant progress has been achieved in the synthesis and applications of boron-containing acenes,but a focused review on this topic has been elusive.Here,we summarize the recent advances in the studies on boron-containing acenes,covering their synthesis,intriguing properties,and various applications in electroluminescence and electronic devices,as well as in biosensors,etc.We hope that this timely review will stimulate new research interest in this unique family of materials and promote their optoelectronic applications.
基金by the National Natural Science Foundation of China(21975048,21771039)the Shanghai Science and Technology Committee(19Dz2270100).
文摘Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluorescent properties,feeding silkworms with fluorescent additives is facile,low-cost and environment friendly,which has the prospect of large-scale production.In this paper,we reviewed the research progress for this aim in the past ten years,and summarized the unified characteristics for the substances that can enter the silk gland by digestive tract of silkworms.The advantages and disadvantages of various fluorescent materials for this application are compared in detail.And the future research directions are suggested to overcome the shortcomings of the present research.
基金Key Research and Development Plan of Shaanxi Province,China(No.2023-YBGY-330)。
文摘In an automatic bobbin management system that simultaneously detects bobbin color and residual yarn,a composite texture segmentation and recognition operation based on an odd partial Gabor filter and multi-color space hierarchical clustering are proposed.Firstly,the parameter-optimized odd partial Gabor filter is used to distinguish bobbin and yarn texture,to explore Garbor parameters for yarn bobbins,and to accurately discriminate frequency characteristics of yarns and texture.Secondly,multi-color clustering segmentation using color spaces such as red,green,blue(RGB)and CIELUV(LUV)solves the problems of over-segmentation and segmentation errors,which are caused by the difficulty of accurately representing the complex and variable color information of yarns in a single-color space and the low contrast between the target and background.Finally,the segmented bobbin is combined with the odd partial Gabor’s edge recognition operator to further distinguish bobbin texture from yarn texture and locate the position and size of the residual yarn.Experimental results show that the method is robust in identifying complex texture,damaged and dyed bobbins,and multi-color yarns.Residual yarn identification can distinguish texture features and residual yarns well and it can be transferred to the detection and differentiation of complex texture,which is significantly better than traditional methods.
基金Project supported by the National Natural Science Foundation of China(61564007)
文摘Multi-color luminescence basing on amorphous Eu^3＋/Tb^3＋ co-doped Zn-A1 hydroxides and their annealed samples were studied in detail. Results suggest that excellent red emissions due to E^u3＋ and green emissions attributed to Tb^3＋ appear under the excitation of favorable wavelength for all the as- prepared amorphous samples. Moreover, the emission intensity depends on the Eu^3＋/Tb^3＋ molar ratio. The samples annealed at 300, 500, and 700 ℃ still exhibit amorphous state, and multi-color lumi- nescence kept in the samples annealed at 300 ℃, while luminescence quenched for the samples annealed at 500 and 700 ℃. However, a broad emission ranging from 450 to 650 nm occurs in some samples annealed at 900 ℃. Further, the fluorescence decay and lifetimes for the as-prepared samples and the samples annealed at 300℃ were investigated. It is found that all the decay curves of emissions due to Tb^3＋ and Eu^3＋ present characteristic double exponential function despite their different lifetimes. The present work may be a good example for developing new multi-color even white light emitting materials.
基金We gratefully acknowledge the Nature Science Foundation of China(21335001,21575126)the Nature Science Foundation of Zhejiang Province(LR14B050001).
文摘Electrochemiluminescence(ECL),also called electrogenerated chemiluminescence,is luminescence that is produced by chemical reactions triggered by electrochemical method.ECL imaging is a novel imaging technique,which can simultaneously provide two kinds of signals of both electrochemistry and optical image.Over the past two decades,ECL imaging has been not only a powerful tool for investigating the fundamental scientific questions such as ECL mechanisms and reaction kinetics,but also a versatile analytical technique for detection of a wide range of analytes including small molecules,DNA,proteins,and cells.In the first part of this review,we briefly describe the reaction mechanisms of ECL generation.Then the review focuses on the research progress on the ECL imaging approach.It is basically introduced from the following five aspects:(i)visualization of electroactive sites on surfaces,(ii)imaging analysis at the single-bead and single-cell levels,(iii)array bioanalysis,(iv)multi-color ECL imaging,and(v)paper chip based on ECL imaging.Finally,some perspectives and future directions in this active research area are presented.
