A phenomenological approach to investigate the effect of interfacial layers on the absorption of metal-dielectric composite at elevated temperatures is put forward by making use of a model in which weakly nonlinear sp...A phenomenological approach to investigate the effect of interfacial layers on the absorption of metal-dielectric composite at elevated temperatures is put forward by making use of a model in which weakly nonlinear spherical metallic particles with linear concentric shells are randomly embedded in a linear host. Corresponding formulae in terms of the interfacial factor are derived in detail by incorporating Taylor expansion and Drude model. We take composite as numerical calculation. It is concluded that such absorption is dependent not only on the temperature, but also on the properties of interfacial layers. Many other interesting phenomena are shown.展开更多
The laser metal deposition （LMD） was conducted on copper by varying the processing parameters in order to achieve the best possible settings. Two sets of experiments were conducted. The deposited composites were cha...The laser metal deposition （LMD） was conducted on copper by varying the processing parameters in order to achieve the best possible settings. Two sets of experiments were conducted. The deposited composites were characterized through the evolving microstructure, microhardness profiling and mechanical properties. It was found that the evolving microstructures of the deposited composites were characterized with primary, secondary and tertiary arms dendrites, acicular microstructure as well as the alpha and beta eutectic structures. From the two sets of experiments performed, it was found that Sample E produced at a laser power of 1200 W and a scanning speed of 1.2 m/min has the highest hardness of HV （190±42） but exhibits some lateral cracks due to its brittle nature, while Sample B produced at laser power of 1200 W and a scanning speed of 0.3 m/min shows no crack and a good microstructure with an increase in dendrites. The strain hardening coefficient of the deposited copper composite obtained in this experiment is 3.35.展开更多
With the widespread application of radionuclide ^235U（VI）, it is inevitable that part of U（VI） is released into the natural environment. The potential toxicity and irreversibility impact on the natural environment...With the widespread application of radionuclide ^235U（VI）, it is inevitable that part of U（VI） is released into the natural environment. The potential toxicity and irreversibility impact on the natural environment has become one of the most forefront pollution problems in nuclear energy utilization. In this work, rod-like metal-organic framework （MOF-5） nanomaterial was synthesized by a solvothermal method and applied to efficiently adsorb U（VI） from aqueous solutions. The batch experimental results showed that the sorp- tion of U（Vl） on MOF-5 was strongly dependent on pH and independent of ionic strength, indicating that the dominant interaction mechanism was inner-sphere surface complexation and electrostatic interac- tion. The maximum sorption capacity of U（Vl） on MOF-5 was 237.0 mg]g at pH 5.0 and T = 298 K, and the sorption equilibrium reached within 5 rain. The thermodynamic parameters indicated that the removal of U（VI） on MOF-5 was a spontaneous and endothermic process. Additionally, the FT-IR and XPS analyses implied that the high sorption capacity of U（Vl） on MOF-5 was mainly attributed to the abundant oxygen-containing functional groups （i.e., C-O and C=O）. Such a facile preparation method and efficient removal performance highlighted the application of MOF-5 as a candidate for rapid and efficient radionuclide contamination＇s elimination in practical applications.展开更多
Highly ordered nanocomposite arrays of Rh6G-Au-AAO are formed by filling anodized aluminum oxide （AAO） with Rhodamine 6G （Rh6G） and gold nanoparticles. The optical properties of Rh6G-Au-AAO are studied by visible ...Highly ordered nanocomposite arrays of Rh6G-Au-AAO are formed by filling anodized aluminum oxide （AAO） with Rhodamine 6G （Rh6G） and gold nanoparticles. The optical properties of Rh6G-Au-AAO are studied by visible absorptive and fluorescent spectroscopy. Compared with the fluorescence spectra of Rh6G-Au in the solution environment, the fluo- rescence peak intensities of Rh6G-Au-AAO are significantly enhanced, the maximum enhancement rate is 5.5, and a constant blue shift of-12 nm of peak positions is presented. The effects come from the spatial confinement of AAO and the inhibition of the fluorescence quenching effect induced by gold nanoparticles. The results show that the nanocomposite structures of fluorescence molecules-metal nanoparticles-AAO have a considerable potential in engineering molecular assemblies and creating functional materials of superior properties for future nanoDhotonics.展开更多
As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are in...As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.展开更多
Optical near-field excitations were investigated on the basis of molecular alignment control of liquid crystals (LCs) on an optically rewritable nanostructure of photoreactive molecular thin films. Twisted nematic (TN...Optical near-field excitations were investigated on the basis of molecular alignment control of liquid crystals (LCs) on an optically rewritable nanostructure of photoreactive molecular thin films. Twisted nematic (TN) cells of LC molecules were constructed utilizing ITO substrates with 260 nm gratings of an azobenzene molecular thin film, fabricated using standing evanescent waves. The polarization changes of light transmitted through the TN cells, which were due to the alignment changes of LC molecules locally rubbed by the azobenzene nanogratings, were observed. Furthermore, we demonstrated local plasmon excitation of Au nanowires deposited on the azobenzene nanogratings using oblique vacuum evaporation, a phenomenon that produced strong anti-optical absorption spectra. The modulation of the local plasmon resonance in metallic nanowires decorated with LC molecules was confirmed.展开更多
A detailed study is presented on magnetic, electrical and optical properties of Gal_xMnxN： Si film grown by metal organic chemical vapor deposition （MOCVD） with high-purity Sill4 as the Si dopant source. The room-t...A detailed study is presented on magnetic, electrical and optical properties of Gal_xMnxN： Si film grown by metal organic chemical vapor deposition （MOCVD） with high-purity Sill4 as the Si dopant source. The room-temperature field dependence magnetization and zero-field-cooled （ZFC）/field-cooled （FC） measurements indicate that the film remains room-temperature ferromagnetism and it declines slightly after Si co-doping. However, room-temperature Hall measurements indicate that the electrical property of the film improves distinctly compared with Gal-xMnxN. Cathode luminescence （CL） measurements show an obvious enhancement in luminous property and different peak strength changes at three different positions. Therefore, we demonstrate that Fermi level and the electron structure of Mn atoms will change with variation of the impurities co-doped and the intrinsic defects and this may be related with room-temperature ferromagnetism and the other corresponding properties of the film.展开更多
The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes t...The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes third-order NLO switches,which are far superior to congeneric optical switches in terms of their performance conversion,versatility,and fast response,were successfully designed and synthesized.The test of their third-order NLO properties proves that the metal complexes exhibit reverse saturable absorption and self-defocusing refraction.After light irradiation,the third-order NLO behavior turns quickly into self-focusing refraction.The relation between the molecular structures and the third-order NLO properties was investigated via1H nuclear magnetic resonance and ultraviolet-visible absorption.The results show that the metal ions have a significant influence on the NLO behavior and reveal the origin of third-order NLO properties via Z-scan determinations,pump-probe technology,and density functional theory calculations.These metal complexes can be used as third-order NLO switches with excellent fatigue resistance and broaden the application range of third-order NLO materials with adjustable performances.展开更多
A mechanical metamaterial that has a tailorable coefficient of thermal expansion(CTE)is promising for guaranteeing the reliability of electrical and optical instruments under thermal fluctuations.Despite growing resea...A mechanical metamaterial that has a tailorable coefficient of thermal expansion(CTE)is promising for guaranteeing the reliability of electrical and optical instruments under thermal fluctuations.Despite growing research on the design and manufacturing of metamaterials with extraordinary CTEs,it remains challenging to achieve a nearly isotropic tailorable CTE while ensuring a sufficient load bearing capacity for applications,such as mechanical supporting frames.In this research,we propose a type of bi-metallic lattice whose CTE is artificially programmed from positive(75 ppm/K)to negative(−45 ppm/K),and whose equivalent modulus can be as high as 80 MPa.The bi-metallic lattice with a tailorable CTE in two orthogonal directions can be readily assembled without special modifications to construct large-scale planar structures with desired isotropic CTEs.A theoretical model that considers the actual configuration of the bi-metallic joint is developed;the model precisely captures the thermal deformations of lattice structures with varied geometries and material compositions.Guided by our theoretical design method,planar metallic structures that were manufactured using Al,Ti,and Invar alloy were experimentally characterized;the structures exhibited outstanding performance when compared with typical engineering materials.展开更多
文摘A phenomenological approach to investigate the effect of interfacial layers on the absorption of metal-dielectric composite at elevated temperatures is put forward by making use of a model in which weakly nonlinear spherical metallic particles with linear concentric shells are randomly embedded in a linear host. Corresponding formulae in terms of the interfacial factor are derived in detail by incorporating Taylor expansion and Drude model. We take composite as numerical calculation. It is concluded that such absorption is dependent not only on the temperature, but also on the properties of interfacial layers. Many other interesting phenomena are shown.
基金supported by the Council of Scientific and Industrial Research(CSIR),National Laser Centre,Rental Pool Programme,Pretoria,South Africa and also for the award of the Africa Laser Centre bursary to the main author
文摘The laser metal deposition （LMD） was conducted on copper by varying the processing parameters in order to achieve the best possible settings. Two sets of experiments were conducted. The deposited composites were characterized through the evolving microstructure, microhardness profiling and mechanical properties. It was found that the evolving microstructures of the deposited composites were characterized with primary, secondary and tertiary arms dendrites, acicular microstructure as well as the alpha and beta eutectic structures. From the two sets of experiments performed, it was found that Sample E produced at a laser power of 1200 W and a scanning speed of 1.2 m/min has the highest hardness of HV （190±42） but exhibits some lateral cracks due to its brittle nature, while Sample B produced at laser power of 1200 W and a scanning speed of 0.3 m/min shows no crack and a good microstructure with an increase in dendrites. The strain hardening coefficient of the deposited copper composite obtained in this experiment is 3.35.
基金supported by the National Key Research and Development Program of China(2017YFA0207002)the National Natural Science Foundation of China(21577032,21607042)+1 种基金the Fundamental Research Funds for the Central Universities(2018ZD11,2018MS114,and 2016MS02)the Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection and the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘With the widespread application of radionuclide ^235U（VI）, it is inevitable that part of U（VI） is released into the natural environment. The potential toxicity and irreversibility impact on the natural environment has become one of the most forefront pollution problems in nuclear energy utilization. In this work, rod-like metal-organic framework （MOF-5） nanomaterial was synthesized by a solvothermal method and applied to efficiently adsorb U（VI） from aqueous solutions. The batch experimental results showed that the sorp- tion of U（Vl） on MOF-5 was strongly dependent on pH and independent of ionic strength, indicating that the dominant interaction mechanism was inner-sphere surface complexation and electrostatic interac- tion. The maximum sorption capacity of U（Vl） on MOF-5 was 237.0 mg]g at pH 5.0 and T = 298 K, and the sorption equilibrium reached within 5 rain. The thermodynamic parameters indicated that the removal of U（VI） on MOF-5 was a spontaneous and endothermic process. Additionally, the FT-IR and XPS analyses implied that the high sorption capacity of U（Vl） on MOF-5 was mainly attributed to the abundant oxygen-containing functional groups （i.e., C-O and C=O）. Such a facile preparation method and efficient removal performance highlighted the application of MOF-5 as a candidate for rapid and efficient radionuclide contamination＇s elimination in practical applications.
基金supported by the National Natural Science Foundation of China (No.60978020)the Key International S&T Cooperation Project (No.2005DFA10170)+3 种基金the National "973 Project" (No.2007CB307001)the National Natural Science Foundation of China (No.60408006)the Natural Science Fund of Tianjin (No.06TXTJJC13500)Program for Changjiang Scholars and Innovative Research Team in Nankai University, and the Cultivation Fund of the Key Scientific and Technical Innovation Project
文摘Highly ordered nanocomposite arrays of Rh6G-Au-AAO are formed by filling anodized aluminum oxide （AAO） with Rhodamine 6G （Rh6G） and gold nanoparticles. The optical properties of Rh6G-Au-AAO are studied by visible absorptive and fluorescent spectroscopy. Compared with the fluorescence spectra of Rh6G-Au in the solution environment, the fluo- rescence peak intensities of Rh6G-Au-AAO are significantly enhanced, the maximum enhancement rate is 5.5, and a constant blue shift of-12 nm of peak positions is presented. The effects come from the spatial confinement of AAO and the inhibition of the fluorescence quenching effect induced by gold nanoparticles. The results show that the nanocomposite structures of fluorescence molecules-metal nanoparticles-AAO have a considerable potential in engineering molecular assemblies and creating functional materials of superior properties for future nanoDhotonics.
基金supported by the National Basic Research Program of China(2014CB931700)the Fundamental Research Funds for the Central Universities(30920130111017 and NE2012004)+1 种基金the Opened Fund of the State Key Laboratory on Integrated Optoelectronics(IOSKL2012KF06)the Program for Eastern Scholar at Shanghai Institutions of Higher Learning(2012-53)
文摘As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.
基金supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan
文摘Optical near-field excitations were investigated on the basis of molecular alignment control of liquid crystals (LCs) on an optically rewritable nanostructure of photoreactive molecular thin films. Twisted nematic (TN) cells of LC molecules were constructed utilizing ITO substrates with 260 nm gratings of an azobenzene molecular thin film, fabricated using standing evanescent waves. The polarization changes of light transmitted through the TN cells, which were due to the alignment changes of LC molecules locally rubbed by the azobenzene nanogratings, were observed. Furthermore, we demonstrated local plasmon excitation of Au nanowires deposited on the azobenzene nanogratings using oblique vacuum evaporation, a phenomenon that produced strong anti-optical absorption spectra. The modulation of the local plasmon resonance in metallic nanowires decorated with LC molecules was confirmed.
文摘A detailed study is presented on magnetic, electrical and optical properties of Gal_xMnxN： Si film grown by metal organic chemical vapor deposition （MOCVD） with high-purity Sill4 as the Si dopant source. The room-temperature field dependence magnetization and zero-field-cooled （ZFC）/field-cooled （FC） measurements indicate that the film remains room-temperature ferromagnetism and it declines slightly after Si co-doping. However, room-temperature Hall measurements indicate that the electrical property of the film improves distinctly compared with Gal-xMnxN. Cathode luminescence （CL） measurements show an obvious enhancement in luminous property and different peak strength changes at three different positions. Therefore, we demonstrate that Fermi level and the electron structure of Mn atoms will change with variation of the impurities co-doped and the intrinsic defects and this may be related with room-temperature ferromagnetism and the other corresponding properties of the film.
基金the National Natural Science Foundation of China(21671174 and U1904172)the Zhongyuan Thousand Talents Project,the Natural Science Foundation of Henan Province(182300410008)the Open Foundation of Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials,Guangxi University(2019GXYSOF12).
文摘The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes third-order NLO switches,which are far superior to congeneric optical switches in terms of their performance conversion,versatility,and fast response,were successfully designed and synthesized.The test of their third-order NLO properties proves that the metal complexes exhibit reverse saturable absorption and self-defocusing refraction.After light irradiation,the third-order NLO behavior turns quickly into self-focusing refraction.The relation between the molecular structures and the third-order NLO properties was investigated via1H nuclear magnetic resonance and ultraviolet-visible absorption.The results show that the metal ions have a significant influence on the NLO behavior and reveal the origin of third-order NLO properties via Z-scan determinations,pump-probe technology,and density functional theory calculations.These metal complexes can be used as third-order NLO switches with excellent fatigue resistance and broaden the application range of third-order NLO materials with adjustable performances.
基金supported by the National Natural Science Foundation of China(Grant Nos.12122202,12002032,and 12002031).
文摘A mechanical metamaterial that has a tailorable coefficient of thermal expansion(CTE)is promising for guaranteeing the reliability of electrical and optical instruments under thermal fluctuations.Despite growing research on the design and manufacturing of metamaterials with extraordinary CTEs,it remains challenging to achieve a nearly isotropic tailorable CTE while ensuring a sufficient load bearing capacity for applications,such as mechanical supporting frames.In this research,we propose a type of bi-metallic lattice whose CTE is artificially programmed from positive(75 ppm/K)to negative(−45 ppm/K),and whose equivalent modulus can be as high as 80 MPa.The bi-metallic lattice with a tailorable CTE in two orthogonal directions can be readily assembled without special modifications to construct large-scale planar structures with desired isotropic CTEs.A theoretical model that considers the actual configuration of the bi-metallic joint is developed;the model precisely captures the thermal deformations of lattice structures with varied geometries and material compositions.Guided by our theoretical design method,planar metallic structures that were manufactured using Al,Ti,and Invar alloy were experimentally characterized;the structures exhibited outstanding performance when compared with typical engineering materials.
