Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacryla...Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.展开更多
The adsorption characteristics of cationic polyelectrolyte poly dimethyl diallyl ammonium chloride （PDADMAC） and anionic polyelectrolyte poly （sodium-p-styrenesulfonate） （PSS） on benzoguanamine formal- dehyde （...The adsorption characteristics of cationic polyelectrolyte poly dimethyl diallyl ammonium chloride （PDADMAC） and anionic polyelectrolyte poly （sodium-p-styrenesulfonate） （PSS） on benzoguanamine formal- dehyde （BGF） particles are investigated. The charging characteristics of BGF particles are changed and con- trolled using electrostatic self-assembly method. A variety of PE,-BGF/SiO2 composite abrasives are obtained. The as-prepared samples are analyzed by zeta potential analysis, transmission electron microscope （TEM） and thermogravimetric （TG） analysis. The composite abrasive slurries are prepared for copper polishing. The poli- shing results indicate that it is SiO2 abrasives, not only coated SiO2 abrasive on polymer particles but also free SiO2 abrasive in slurry, that offer the polishing action. The material removal rates of copper polishing are 264 nm/min, 348 nm/min and 476 nm/min using single SiO2 abrasive slurry, PE0-BGF/SiO2 mixed abrasive slur- ry and PE3-BGF/SiO2 composite abrasive slurry, respectively. The surface roughness Ra of copper wafer （with 5μm×5μm district） is decreased from 0.166 μm to 3.7 nm, 2.6 nm and 1.5 nm, and the surface peak-valley values Rrv are less than 20 nm, 14 nm and 10 nm using these kinds of slurries, respectively. Key words ： chemico-mechanical polishing; polishing slurry; composite abrasives ; polyelectrolyte ; copper展开更多
Sulfonatocalix[4]arene lowers the critical aggregation concentration of fluorocarbon surfactant pronouncedly by a factor of ca.100 to form binary amphiphilic aggregates on the basis of host-guest complexation,which wa...Sulfonatocalix[4]arene lowers the critical aggregation concentration of fluorocarbon surfactant pronouncedly by a factor of ca.100 to form binary amphiphilic aggregates on the basis of host-guest complexation,which was identified by1H NMR spectroscopy,fluorescence spectroscopy,optical transmittance spectroscopy,dynamic laser scattering,high-resolution transmission electron microscopy,scanning electron microscopy,and surface tension experiments.Moreover,the resulting aggregates can respond to external stimuli,including temperature and inclusion of competitor guest.Therefore,the present system may have potential applications in drug delivery systems.展开更多
The optical guiding of a moderately intense laser pulse in a parabolic preformed plasma channel is analyzed by means of the variational method.Relativistic,ponderomotive and their coupling nonlinearities are included....The optical guiding of a moderately intense laser pulse in a parabolic preformed plasma channel is analyzed by means of the variational method.Relativistic,ponderomotive and their coupling nonlinearities are included.The conditions for periodic defocusing and focusing,as well as constant spot size propagation are given.It is found that the laser focusing is released by the coupling of relativistic and ponderomotive nonlinearities.展开更多
A series of phosphine oxide-functionalized polyfluorene derivatives,PFH-PO-40-1 (P1),PFH-PO-20-1 (P2),PFH-PO-10-1 (P3),and PFH-PO-1-1 (P4),were prepared via a palladium-mediated Suzuki cross-coupling reaction.The stru...A series of phosphine oxide-functionalized polyfluorene derivatives,PFH-PO-40-1 (P1),PFH-PO-20-1 (P2),PFH-PO-10-1 (P3),and PFH-PO-1-1 (P4),were prepared via a palladium-mediated Suzuki cross-coupling reaction.The structures and purities of all polymers were fully characterized by 1H and 13C NMR,UV-vis and photoluminescent spectroscopy,gel permeation chromatography,and TGA/DSC.Their emission features showed single broad peaks at about 445 nm in film,compared with those in dilute solutions,which might be caused by some degree of aggregation in the excited states of the backbones.The best electroluminescence (EL) performance of these polymers with configuration of ITO/PEDOT:PSS/Polymer/Alq3/LiF/Al was obtained from P1 (current efficiency was 4.2 Cd/A at 6V).展开更多
Coronavirus disease 2019(COVID-19),caused by SARS-CoV-2,has rapidly spread and caused a severe global pandemic.Because no specific drugs are available for COVID-19 and few vaccines are available for SARS-CoV-2,accurat...Coronavirus disease 2019(COVID-19),caused by SARS-CoV-2,has rapidly spread and caused a severe global pandemic.Because no specific drugs are available for COVID-19 and few vaccines are available for SARS-CoV-2,accurate and rapid diagnosis of COVID-19 has been the most crucial measure to control this pandemic.Here,we developed a portable bifunctional electrical detector based on graphene fieldeffect transistors for SARS-CoV-2 through either nucleic acid hybridization or antigen-antibody protein interaction,with ultra-low limits of detection of~0.1 and~1 fg mL^(−1) in phosphate buffer saline,respectively.We validated our method by assessment of RNA extracts from the oropharyngeal swabs of ten COVID-19 patients and eight healthy subjects,and the IgM/IgG antibodies from serum specimens of six COVID-19 patients and three healthy subjects.Here we show that the diagnostic results are in excellent agreement with the findings of polymerase chain reaction-based optical methods;they also exhibit rapid detection speed(~10 min for nucleic acid detection and~5 min for immunoassay).Therefore,our assay provides an efficient,accurate tool for high-throughput point-of-care testing.展开更多
In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computa...In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefrac- rive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. ~, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different ~, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic.展开更多
基金the Natural Science Foundation of Hunan Province (No. 06JJ4117).
文摘Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.
基金Natural Science Foundation of Zhejiang Province(No.Z1080625)
文摘The adsorption characteristics of cationic polyelectrolyte poly dimethyl diallyl ammonium chloride （PDADMAC） and anionic polyelectrolyte poly （sodium-p-styrenesulfonate） （PSS） on benzoguanamine formal- dehyde （BGF） particles are investigated. The charging characteristics of BGF particles are changed and con- trolled using electrostatic self-assembly method. A variety of PE,-BGF/SiO2 composite abrasives are obtained. The as-prepared samples are analyzed by zeta potential analysis, transmission electron microscope （TEM） and thermogravimetric （TG） analysis. The composite abrasive slurries are prepared for copper polishing. The poli- shing results indicate that it is SiO2 abrasives, not only coated SiO2 abrasive on polymer particles but also free SiO2 abrasive in slurry, that offer the polishing action. The material removal rates of copper polishing are 264 nm/min, 348 nm/min and 476 nm/min using single SiO2 abrasive slurry, PE0-BGF/SiO2 mixed abrasive slur- ry and PE3-BGF/SiO2 composite abrasive slurry, respectively. The surface roughness Ra of copper wafer （with 5μm×5μm district） is decreased from 0.166 μm to 3.7 nm, 2.6 nm and 1.5 nm, and the surface peak-valley values Rrv are less than 20 nm, 14 nm and 10 nm using these kinds of slurries, respectively. Key words ： chemico-mechanical polishing; polishing slurry; composite abrasives ; polyelectrolyte ; copper
基金supported by the National Basic Research Program of China(2011CB932502)the National Natural Science Foundation of China(91227107 and 21172119)
文摘Sulfonatocalix[4]arene lowers the critical aggregation concentration of fluorocarbon surfactant pronouncedly by a factor of ca.100 to form binary amphiphilic aggregates on the basis of host-guest complexation,which was identified by1H NMR spectroscopy,fluorescence spectroscopy,optical transmittance spectroscopy,dynamic laser scattering,high-resolution transmission electron microscopy,scanning electron microscopy,and surface tension experiments.Moreover,the resulting aggregates can respond to external stimuli,including temperature and inclusion of competitor guest.Therefore,the present system may have potential applications in drug delivery systems.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 11047152,11147005,and 11178002the Natural Science Foundation of Jiangxi Province under Grant No. 2010GQW0048
文摘The optical guiding of a moderately intense laser pulse in a parabolic preformed plasma channel is analyzed by means of the variational method.Relativistic,ponderomotive and their coupling nonlinearities are included.The conditions for periodic defocusing and focusing,as well as constant spot size propagation are given.It is found that the laser focusing is released by the coupling of relativistic and ponderomotive nonlinearities.
基金supported by the National Basic Research Program of China (2006CB921602 and 2009CB623601)National Natural Science Foundation of China,and Hewlett Packard Company
文摘A series of phosphine oxide-functionalized polyfluorene derivatives,PFH-PO-40-1 (P1),PFH-PO-20-1 (P2),PFH-PO-10-1 (P3),and PFH-PO-1-1 (P4),were prepared via a palladium-mediated Suzuki cross-coupling reaction.The structures and purities of all polymers were fully characterized by 1H and 13C NMR,UV-vis and photoluminescent spectroscopy,gel permeation chromatography,and TGA/DSC.Their emission features showed single broad peaks at about 445 nm in film,compared with those in dilute solutions,which might be caused by some degree of aggregation in the excited states of the backbones.The best electroluminescence (EL) performance of these polymers with configuration of ITO/PEDOT:PSS/Polymer/Alq3/LiF/Al was obtained from P1 (current efficiency was 4.2 Cd/A at 6V).
基金the National Key R&D Program of China(2017YFA0204901)the National Natural Science Foundation of China(21727806,21772003 and 21933001)+1 种基金the Tencent Foundation through the XPLORER PRIZE,Guangdong Major Project of Basic and Applied Basic Research(2019B030302007)Beijing National Laboratory for Molecular Sciences(BNLMS201901)。
文摘Coronavirus disease 2019(COVID-19),caused by SARS-CoV-2,has rapidly spread and caused a severe global pandemic.Because no specific drugs are available for COVID-19 and few vaccines are available for SARS-CoV-2,accurate and rapid diagnosis of COVID-19 has been the most crucial measure to control this pandemic.Here,we developed a portable bifunctional electrical detector based on graphene fieldeffect transistors for SARS-CoV-2 through either nucleic acid hybridization or antigen-antibody protein interaction,with ultra-low limits of detection of~0.1 and~1 fg mL^(−1) in phosphate buffer saline,respectively.We validated our method by assessment of RNA extracts from the oropharyngeal swabs of ten COVID-19 patients and eight healthy subjects,and the IgM/IgG antibodies from serum specimens of six COVID-19 patients and three healthy subjects.Here we show that the diagnostic results are in excellent agreement with the findings of polymerase chain reaction-based optical methods;they also exhibit rapid detection speed(~10 min for nucleic acid detection and~5 min for immunoassay).Therefore,our assay provides an efficient,accurate tool for high-throughput point-of-care testing.
基金Supported by the National Natural Science Foundation of China under Grant No.11272023the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)Supported by the Fundamental Research Funds for the Central Universities of China under Grant No.2011BUPTYB02
文摘In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefrac- rive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. ~, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different ~, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic.
