Langevin dynamical simulations are performed to determine the bulk modulus in twodimensional(2D) dusty plasmas from uniform periodic radial compressions. The bulk modulus is calculated directly from its physical defin...Langevin dynamical simulations are performed to determine the bulk modulus in twodimensional(2D) dusty plasmas from uniform periodic radial compressions. The bulk modulus is calculated directly from its physical definition of the ratio of the internal pressure/stress to the volume strain. Under various conditions, the bulk moduli obtained agree with the previous theoretical derivations from completely different approaches. It is found that the bulk moduli of2D Yukawa solids and liquids are almost independent of the system temperature and the external compressional frequency.展开更多
Alloy and small size nanostructure s are favorable to catalytical performance,but not to surface-enhanced Raman spectroscopy(SERS) applications.Integrating SERS and catalytic activity into the nanocrystals with both a...Alloy and small size nanostructure s are favorable to catalytical performance,but not to surface-enhanced Raman spectroscopy(SERS) applications.Integrating SERS and catalytic activity into the nanocrystals with both alloy and small size structures is of great interest in fabrication of SERS platform to in situ monitor catalytical reaction.Herein,we report a facile method to synthesize Au@AgPd trimetallic nanoflowers(Au@AgPd NFs) with both SERS and catalytic activities,through simultaneous selective growth of Ag and Pd on Au core to form highly-branched alloy shell.These nanocrystals have the properties of small sizes,defects abundance,and highly-dispersed alloy shell which offer superior catalytic activity,while the merits of monodisperse,excellent stability,and highly-branched shell and core/alloy-shell structure promise the enhanced SERS activity.We further studied their growth mechanisms,and found that the ratio of Ag to Pd,sizes of Au core,and surfactant cetyltrimethylammonium bromide together determine this special structure.Using this as-synthesized nanocrystals,a monolayer bifunctional platform with both SERS and catalytical activity was fabricated through selfassembly at air/water interface,and applied to in situ SERS monitoring the reaction process of Pdcatalyzed hydrogenation of 4-nitrothiophenol to 4-aminothio p henol.展开更多
基金supported by National Natural Science Foundation of China(Nos.12175159 and 11875199)the 1000 Youth Talents Plan,startup funds from Soochow Universitythe Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘Langevin dynamical simulations are performed to determine the bulk modulus in twodimensional(2D) dusty plasmas from uniform periodic radial compressions. The bulk modulus is calculated directly from its physical definition of the ratio of the internal pressure/stress to the volume strain. Under various conditions, the bulk moduli obtained agree with the previous theoretical derivations from completely different approaches. It is found that the bulk moduli of2D Yukawa solids and liquids are almost independent of the system temperature and the external compressional frequency.
基金supported by the National Key R&D Program of China(No.2016YFA0203102)the National Natural Science Foundation of China(Nos.21620102008 and 21827815)。
文摘Alloy and small size nanostructure s are favorable to catalytical performance,but not to surface-enhanced Raman spectroscopy(SERS) applications.Integrating SERS and catalytic activity into the nanocrystals with both alloy and small size structures is of great interest in fabrication of SERS platform to in situ monitor catalytical reaction.Herein,we report a facile method to synthesize Au@AgPd trimetallic nanoflowers(Au@AgPd NFs) with both SERS and catalytic activities,through simultaneous selective growth of Ag and Pd on Au core to form highly-branched alloy shell.These nanocrystals have the properties of small sizes,defects abundance,and highly-dispersed alloy shell which offer superior catalytic activity,while the merits of monodisperse,excellent stability,and highly-branched shell and core/alloy-shell structure promise the enhanced SERS activity.We further studied their growth mechanisms,and found that the ratio of Ag to Pd,sizes of Au core,and surfactant cetyltrimethylammonium bromide together determine this special structure.Using this as-synthesized nanocrystals,a monolayer bifunctional platform with both SERS and catalytical activity was fabricated through selfassembly at air/water interface,and applied to in situ SERS monitoring the reaction process of Pdcatalyzed hydrogenation of 4-nitrothiophenol to 4-aminothio p henol.
