The influence of stabilizing agents and reaction time on the luminescent properties of water-soluble CdTe quantum dots(QDs) was discussed.The thioglycolic acid(TGA)-CdTe ODs were characterized by TEM,XRD and FTIR.It i...The influence of stabilizing agents and reaction time on the luminescent properties of water-soluble CdTe quantum dots(QDs) was discussed.The thioglycolic acid(TGA)-CdTe ODs were characterized by TEM,XRD and FTIR.It is found that larger-size QDs can be synthesized more easily when L-cysteine(Cys) or golutathione(GSH) is chosen as stabilizing agent and TGA is proper to prepare highly luminescent QDs because of the effect between Cd2+ and sulfhydryl group.Furthermore,the absorption wavelength,full width at half maximum(FWHM),stokes shift,photoluminescence(PL) quantum yield and PL stability of TGA-CdTe are strongly dependent on reaction time,in which the absorption wavelength changes against reaction time with an exponential function.The TGA-CdTe QDs prepared at 2 h possess more excellent luminescent properties.展开更多
A series of N‐CQDs/Ag2CO3composite crystals(where N‐CQDs=Nitrogen doped carbon quantumdots)were prepared by adding different volumes of a solution of N‐CQDs during Ag2CO3crystalgrowth.Under irradiation from a350‐W...A series of N‐CQDs/Ag2CO3composite crystals(where N‐CQDs=Nitrogen doped carbon quantumdots)were prepared by adding different volumes of a solution of N‐CQDs during Ag2CO3crystalgrowth.Under irradiation from a350‐W Xe lamp light(with optical filter,λ≥420nm),the performanceof N‐CQDs/Ag2CO3in photocatalytic degradation of phenol was evaluated.The as‐preparedsamples were analyzed by XRD,SEM,TEM,BET,element mapping,UV‐vis DRS,FT‐IR,XPS,transientphotocurrent response and EIS testing.The results showed that after coupling with trace amountsof N‐CQDs,both the photocatalytic activity and stability of Ag2CO3were greatly boosted.The additionof N‐CQDs solution influenced the crystallization of Ag2CO3,resulting in a distinct decrease inAg2CO3crystal size and an obvious increase in surface area.Moreover,the charge transfer resistancewas greatly reduced,and the separation efficiency of photogenerated electrons and holes wasstrongly promoted.The presence of NCQDs on the surface of the catalysts facilitates the transfer ofphotogenerated electrons,slowing the photocorrosion rate of Ag2CO3,and then resulting in higherstability than bare Ag2CO3in degradation.The synergistic effect of the improvement of morphologyand charge transfer rate thus accounted for the superior photocatalytic performance ofN‐CQDs/Ag2CO3.展开更多
A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov...A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov/ne serum albumin （BSA） was proposed. The citrate-stabilized CdSe/CdS （QDs） were synthesized by using Se powder and Na2S as precursors instead of any pyrophoric organometallic precursors. The modified CdSe/CdS QDs are brighter and more stable against photobleaching in comparison with organic fluorophores. At pH 7.0, the fluorescence signal of CdSe/CdS is enhanced by increasing the concentration of BSA in the range of 0.1-10 μg/mL, and the low detection limit is 0.06 μg/mL. A linear relationship between the enhanced fluorescence peak intensity （△F） and BSA concentration （c） is established using equation △F=50.7c＋16.4 （R=0.996 36）. Results of determination for BSA in three synthetic samples are identical with the true values, and the recovery （98.9%-102.4%） and relative standard deviation （RSD, 1.8%-2.5%） are satisfactory.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
Classical network coding permits all internal nodes to encode or decode the incoming messages over proper fields in order to complete a network multicast. Similar quantum encoding scheme cannot be easily followed beca...Classical network coding permits all internal nodes to encode or decode the incoming messages over proper fields in order to complete a network multicast. Similar quantum encoding scheme cannot be easily followed because of various quantum no-go theorems. In this paper, to avoid these theorems in quantum multiple-source networks, we present a photonic strategy by exploring quantum transferring approaches assisted by the weak cross-Kerr nonlinearity. The internal node may nearly deterministically fuse all incoming photons into a single photon with multiple modes. The fused single photon may be transmitted using twophotonic hyperentanglement as a quantum resource. The quantum splitting as the inverse operation of the quantum fusion allows forwarding quantum states under the quantum no-cloning theorem. Furthermore, quantum addressing schemes are presented to complete the quantum transmissions on multiple-source networks going beyond the classical network broadcasts or quantum n-pair transmissions in terms of their reduced forms.展开更多
基金Projects(10805069,10405034) supported by the National Natural Science Foundation of China
文摘The influence of stabilizing agents and reaction time on the luminescent properties of water-soluble CdTe quantum dots(QDs) was discussed.The thioglycolic acid(TGA)-CdTe ODs were characterized by TEM,XRD and FTIR.It is found that larger-size QDs can be synthesized more easily when L-cysteine(Cys) or golutathione(GSH) is chosen as stabilizing agent and TGA is proper to prepare highly luminescent QDs because of the effect between Cd2+ and sulfhydryl group.Furthermore,the absorption wavelength,full width at half maximum(FWHM),stokes shift,photoluminescence(PL) quantum yield and PL stability of TGA-CdTe are strongly dependent on reaction time,in which the absorption wavelength changes against reaction time with an exponential function.The TGA-CdTe QDs prepared at 2 h possess more excellent luminescent properties.
基金supported by the National Natural Science Foundation of China(21567008,21607064,21707055)Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology+2 种基金Program of 5511 Talents in Scientific and Technological Innovation of Jiangxi Province(20165BCB18014)Academic and Technical Leaders of the Main Disciplines in Jiangxi Province(20172BCB22018)Jiangxi Province Natural Science Foundation(20161BAB203090)~~
文摘A series of N‐CQDs/Ag2CO3composite crystals(where N‐CQDs=Nitrogen doped carbon quantumdots)were prepared by adding different volumes of a solution of N‐CQDs during Ag2CO3crystalgrowth.Under irradiation from a350‐W Xe lamp light(with optical filter,λ≥420nm),the performanceof N‐CQDs/Ag2CO3in photocatalytic degradation of phenol was evaluated.The as‐preparedsamples were analyzed by XRD,SEM,TEM,BET,element mapping,UV‐vis DRS,FT‐IR,XPS,transientphotocurrent response and EIS testing.The results showed that after coupling with trace amountsof N‐CQDs,both the photocatalytic activity and stability of Ag2CO3were greatly boosted.The additionof N‐CQDs solution influenced the crystallization of Ag2CO3,resulting in a distinct decrease inAg2CO3crystal size and an obvious increase in surface area.Moreover,the charge transfer resistancewas greatly reduced,and the separation efficiency of photogenerated electrons and holes wasstrongly promoted.The presence of NCQDs on the surface of the catalysts facilitates the transfer ofphotogenerated electrons,slowing the photocorrosion rate of Ag2CO3,and then resulting in higherstability than bare Ag2CO3in degradation.The synergistic effect of the improvement of morphologyand charge transfer rate thus accounted for the superior photocatalytic performance ofN‐CQDs/Ag2CO3.
基金Project(50772133) supported by the National Natural Science Foundation of China
文摘A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov/ne serum albumin （BSA） was proposed. The citrate-stabilized CdSe/CdS （QDs） were synthesized by using Se powder and Na2S as precursors instead of any pyrophoric organometallic precursors. The modified CdSe/CdS QDs are brighter and more stable against photobleaching in comparison with organic fluorophores. At pH 7.0, the fluorescence signal of CdSe/CdS is enhanced by increasing the concentration of BSA in the range of 0.1-10 μg/mL, and the low detection limit is 0.06 μg/mL. A linear relationship between the enhanced fluorescence peak intensity （△F） and BSA concentration （c） is established using equation △F=50.7c＋16.4 （R=0.996 36）. Results of determination for BSA in three synthetic samples are identical with the true values, and the recovery （98.9%-102.4%） and relative standard deviation （RSD, 1.8%-2.5%） are satisfactory.
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.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61772437, 61702427, and 61671087)the Natural Science Foundation of Shandong Province (Grant No. ZR2015FL024)+2 种基金Sichuan Youth Science and Technique Foundation (Grant No. 2017JQ0048)Fundamental Research Funds for the Central Universities (Grant No. 2682014CX095)Chuying Fellowship
文摘Classical network coding permits all internal nodes to encode or decode the incoming messages over proper fields in order to complete a network multicast. Similar quantum encoding scheme cannot be easily followed because of various quantum no-go theorems. In this paper, to avoid these theorems in quantum multiple-source networks, we present a photonic strategy by exploring quantum transferring approaches assisted by the weak cross-Kerr nonlinearity. The internal node may nearly deterministically fuse all incoming photons into a single photon with multiple modes. The fused single photon may be transmitted using twophotonic hyperentanglement as a quantum resource. The quantum splitting as the inverse operation of the quantum fusion allows forwarding quantum states under the quantum no-cloning theorem. Furthermore, quantum addressing schemes are presented to complete the quantum transmissions on multiple-source networks going beyond the classical network broadcasts or quantum n-pair transmissions in terms of their reduced forms.
