Complex plasma fluctuation processes have been extensively studied in many aspects,especially lattice waves in strongly coupled plasma crystals,which are of great significance for understanding fundamental physical ph...Complex plasma fluctuation processes have been extensively studied in many aspects,especially lattice waves in strongly coupled plasma crystals,which are of great significance for understanding fundamental physical phenomena.A challenge of experimental investigations in two-dimensional strongly coupled complex plasma crystals is to keep the main body and foreign particles of different masses on the same horizontal plane.To solve the problem,we have proposed a potential well formed by two negatively biased grids to bind the negatively charged particles in a two-dimensional(2D)plane,thus achieving a 2D plasma crystal in the microgravity environment.The study of such phenomena in complex plasma crystals under microgravity environment then becomes possible.In this paper,we focus on the continuum spectrum,including both phonon and optic branches of the impurity mode in a 2D system in microgravity environments.The results show the dispersion relation of the longitudinal and transverse impurity oscillation modes and their properties.Considering the macroscopic visibility of complex mesoscopic particle lattices,theoretical and experimental studies on this kind of complex plasma systems will help us further understand the physical nature of a wide range of condensed matters.展开更多
We theoretically demonstrate the imaging properties of a complex two-dimensional(2D) face-centered square lattice photonic crystal(PC) made from germanium cylinders in air background. The finitedifference time-domain(...We theoretically demonstrate the imaging properties of a complex two-dimensional(2D) face-centered square lattice photonic crystal(PC) made from germanium cylinders in air background. The finitedifference time-domain(FDTD) method is employed to calculate the band structure and simulate image construction. The band diagram of the complex structure is significantly compressed. Negative refraction occurs in the second energy band with negative phase velocity at a frequency of 0.228(2πc/a), which is lower than results from previous studies. Lower negative refraction frequency leads to higher image resolution. Numerical results show that the spatial resolution of the system reaches 0.7296λ, which is lower than the incident wavelength.展开更多
The vanadium（V） peroxo complexes containing Mannich base ligands having composition Na[VO（O2）2（L-L）]·H2O [where L-L=morpholinobenzyl acetamide （MBA）, piperidinobenzyl acetamide （PBA）, morpholinobenzyl b...The vanadium（V） peroxo complexes containing Mannich base ligands having composition Na[VO（O2）2（L-L）]·H2O [where L-L=morpholinobenzyl acetamide （MBA）, piperidinobenzyl acetamide （PBA）, morpholinobenzyl benzamide （MBB）, piperidinobenzyl benzamide （PBB）, morpholinomethyl benzamide （MMB）, piperidinomethyl benzamide （PMB）, morpholinobenzyl formamide （MBF）, piperdinobenzyl formamide （PBF）] have been reported. The complexes have been prepared by stirring vanadium pentoxide with excess of 30% aque- ous-H202 followed by treatment with ethanolic solution of the ligand and finally maintained the pH of the reaction mixture by adding dilute solution of sodium hydroxide. The synthesized complexes have been characterized by various physico-chemical techniques, via elemental analysis, molar conductivity, magnetic susceptibility measure- ments, infra red, electronic, mass, ~H NMR spectral and TGA/DTA studies. These studies revealed that the synthesized complexes are uni-univalent electrolytes and diamagnetic in nature. The ligands are bound to metal in a bi- dentate mode through carbonyl oxygen and the ring nitrogen. Thermal analysis result provides conclusive evidence for the presence of one molecule of lattice water in the complexes. Mass spectra confirm the molecular mass of the complexes.展开更多
The effect of the number of defect particles on the structure and dispersion relations of a two-dimensional(2D) dust lattice is studied by molecular dynamics(MD) simulation. The dust lattice structures are characteriz...The effect of the number of defect particles on the structure and dispersion relations of a two-dimensional(2D) dust lattice is studied by molecular dynamics(MD) simulation. The dust lattice structures are characterized by particle distribution, nearest neighbor configuration and pair correlation function. The current autocorrelation function, the dispersion relation and sound speed are used to represent the wave properties. The wave propagation of the dust lattice closely relates to the lattice structure. It shows that the number of defect particles can affect the dust lattice local structure and then affect the dispersion relations of waves propagating in it. The presence of defect particles has a greater effect on the transverse waves than on the longitudinal waves of the dust lattice. The appropriate number of defect particles can weaken the anisotropy property of the lattice.展开更多
Epitaxial PrBaCo_(2)O_(5+δ)(PBCO,0≤δ≤1)thin films were deposited by pulsed laser deposition.The structural and electrical properties of the films were characterized at high temperatures in reduced environments.X-r...Epitaxial PrBaCo_(2)O_(5+δ)(PBCO,0≤δ≤1)thin films were deposited by pulsed laser deposition.The structural and electrical properties of the films were characterized at high temperatures in reduced environments.X-ray diffraction scans at high temperature in reduced environment show potential structural transitions of PBCO as evidenced by both a large(Dl=0.335 nm)expansion of the out-plane(caxis)lattice,due to thermal and chemical expansion,and a step in the expansion of the c-axis lattice parameter.These transitions indicate the presence of oxygen vacancy ordering as the oxygen content in the films is reduced.Resistivity measurements under the same environments also show evidence of sharp transitions related with the structural transformations.This study helps the understanding of the structure-property relationship of PBCO at high temperature and provides important technological information to utilize these materials for solid oxide fuel cell at intermediate temperatures.展开更多
In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpi...In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpired solar air collector(UTC).Besides the lattice Boltzmann equation(LBE) for time evolution of particle distribution function for fluid field,we introduce an analogy,LBE for time evolution of distribution function for temperature.Both temperature fields of fluid(air) and solid(porous media) are modeled.We study the effects of fan velocity,solar radiation intensity,porosity,etc.on the thermal performance of the UTC.In general,our simulation results are in good agreement with what in literature.With the current system setting,both fan velocity and solar radiation intensity have significant effect on the thermal performance of the UTC.However,it is shown that the porosity has negligible effect on the heat collector indicating the current system setting might not be realistic.Further examinations of thermal performance in different UTC systems are ongoing.The results are expected to present in near future.展开更多
The copper complexes of biuret have been synthesized by solid phase react ion with microwave irradiation. The compositions and structures of the complexes are characterized by elemental analysis, molar conductance, in...The copper complexes of biuret have been synthesized by solid phase react ion with microwave irradiation. The compositions and structures of the complexes are characterized by elemental analysis, molar conductance, infrared spectra, e lectronic spectra, magnetic susceptibility, thermogravimetric and differential t hermal analysis, X-ray powder diffraction. The two complexes have the composit ions of Cl2(A) and (NO3)2(B)(bi=NH2CONHCONH2) and the molecula r formulae of CuC4H10O4N6Cl2 and CuC4H10O10N8, respectively. The molar conductan ce data show that the complexes are 1∶2 electrolyte. Infrared spectra of the c omplexes show oxygen atoms have been coordinated with divalent copper ion. The t hermal decomposition processes of the complexes show that the final residues are all cupper oxide. The results of indexes to the X-ray powder diffraction data indicate that the crystal structure of the complexes belong to monoclinic syste m, the lattice parameters are: a=0.6976nm,b=1.1546 nm,c=2.1689nm,a=96.80 1.7346nm3 for A; and a=0.7096nm,b=1.1359 nm,c=2.1002 nm,a=97.05nm3 for B, respectively.展开更多
基金supported by“Undergraduate Innovation and Entrepreneurship Training Program”at Harbin Institute of Technology。
文摘Complex plasma fluctuation processes have been extensively studied in many aspects,especially lattice waves in strongly coupled plasma crystals,which are of great significance for understanding fundamental physical phenomena.A challenge of experimental investigations in two-dimensional strongly coupled complex plasma crystals is to keep the main body and foreign particles of different masses on the same horizontal plane.To solve the problem,we have proposed a potential well formed by two negatively biased grids to bind the negatively charged particles in a two-dimensional(2D)plane,thus achieving a 2D plasma crystal in the microgravity environment.The study of such phenomena in complex plasma crystals under microgravity environment then becomes possible.In this paper,we focus on the continuum spectrum,including both phonon and optic branches of the impurity mode in a 2D system in microgravity environments.The results show the dispersion relation of the longitudinal and transverse impurity oscillation modes and their properties.Considering the macroscopic visibility of complex mesoscopic particle lattices,theoretical and experimental studies on this kind of complex plasma systems will help us further understand the physical nature of a wide range of condensed matters.
文摘We theoretically demonstrate the imaging properties of a complex two-dimensional(2D) face-centered square lattice photonic crystal(PC) made from germanium cylinders in air background. The finitedifference time-domain(FDTD) method is employed to calculate the band structure and simulate image construction. The band diagram of the complex structure is significantly compressed. Negative refraction occurs in the second energy band with negative phase velocity at a frequency of 0.228(2πc/a), which is lower than results from previous studies. Lower negative refraction frequency leads to higher image resolution. Numerical results show that the spatial resolution of the system reaches 0.7296λ, which is lower than the incident wavelength.
文摘The vanadium（V） peroxo complexes containing Mannich base ligands having composition Na[VO（O2）2（L-L）]·H2O [where L-L=morpholinobenzyl acetamide （MBA）, piperidinobenzyl acetamide （PBA）, morpholinobenzyl benzamide （MBB）, piperidinobenzyl benzamide （PBB）, morpholinomethyl benzamide （MMB）, piperidinomethyl benzamide （PMB）, morpholinobenzyl formamide （MBF）, piperdinobenzyl formamide （PBF）] have been reported. The complexes have been prepared by stirring vanadium pentoxide with excess of 30% aque- ous-H202 followed by treatment with ethanolic solution of the ligand and finally maintained the pH of the reaction mixture by adding dilute solution of sodium hydroxide. The synthesized complexes have been characterized by various physico-chemical techniques, via elemental analysis, molar conductivity, magnetic susceptibility measure- ments, infra red, electronic, mass, ~H NMR spectral and TGA/DTA studies. These studies revealed that the synthesized complexes are uni-univalent electrolytes and diamagnetic in nature. The ligands are bound to metal in a bi- dentate mode through carbonyl oxygen and the ring nitrogen. Thermal analysis result provides conclusive evidence for the presence of one molecule of lattice water in the complexes. Mass spectra confirm the molecular mass of the complexes.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12075315 and 11675261)。
文摘The effect of the number of defect particles on the structure and dispersion relations of a two-dimensional(2D) dust lattice is studied by molecular dynamics(MD) simulation. The dust lattice structures are characterized by particle distribution, nearest neighbor configuration and pair correlation function. The current autocorrelation function, the dispersion relation and sound speed are used to represent the wave properties. The wave propagation of the dust lattice closely relates to the lattice structure. It shows that the number of defect particles can affect the dust lattice local structure and then affect the dispersion relations of waves propagating in it. The presence of defect particles has a greater effect on the transverse waves than on the longitudinal waves of the dust lattice. The appropriate number of defect particles can weaken the anisotropy property of the lattice.
基金This research was partially supported by the National Institute on Minority Health and Health Disparities of the National Institutes of Health under Award Number G12MD007591This work was performed,in part,at the Center for Integrated Nanotechnologies,an Office of Science User Facility operated for the U.S.Department of Energy(DOE)Office of Science.Los Alamos National Laboratory,an affirmative action equal opportunity employer,is operated by Los Alamos National Security,LLC,for the National Nuclear Security Administration of the U.S.Department of Energy under contract DE-AC52-06NA25396.
文摘Epitaxial PrBaCo_(2)O_(5+δ)(PBCO,0≤δ≤1)thin films were deposited by pulsed laser deposition.The structural and electrical properties of the films were characterized at high temperatures in reduced environments.X-ray diffraction scans at high temperature in reduced environment show potential structural transitions of PBCO as evidenced by both a large(Dl=0.335 nm)expansion of the out-plane(caxis)lattice,due to thermal and chemical expansion,and a step in the expansion of the c-axis lattice parameter.These transitions indicate the presence of oxygen vacancy ordering as the oxygen content in the films is reduced.Resistivity measurements under the same environments also show evidence of sharp transitions related with the structural transformations.This study helps the understanding of the structure-property relationship of PBCO at high temperature and provides important technological information to utilize these materials for solid oxide fuel cell at intermediate temperatures.
基金Supported by the National Nature Science Foundation of China under Grant Nos. 10932010,11072220,11072229,U1262109,51176172,and 10972208
文摘In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpired solar air collector(UTC).Besides the lattice Boltzmann equation(LBE) for time evolution of particle distribution function for fluid field,we introduce an analogy,LBE for time evolution of distribution function for temperature.Both temperature fields of fluid(air) and solid(porous media) are modeled.We study the effects of fan velocity,solar radiation intensity,porosity,etc.on the thermal performance of the UTC.In general,our simulation results are in good agreement with what in literature.With the current system setting,both fan velocity and solar radiation intensity have significant effect on the thermal performance of the UTC.However,it is shown that the porosity has negligible effect on the heat collector indicating the current system setting might not be realistic.Further examinations of thermal performance in different UTC systems are ongoing.The results are expected to present in near future.
文摘The copper complexes of biuret have been synthesized by solid phase react ion with microwave irradiation. The compositions and structures of the complexes are characterized by elemental analysis, molar conductance, infrared spectra, e lectronic spectra, magnetic susceptibility, thermogravimetric and differential t hermal analysis, X-ray powder diffraction. The two complexes have the composit ions of Cl2(A) and (NO3)2(B)(bi=NH2CONHCONH2) and the molecula r formulae of CuC4H10O4N6Cl2 and CuC4H10O10N8, respectively. The molar conductan ce data show that the complexes are 1∶2 electrolyte. Infrared spectra of the c omplexes show oxygen atoms have been coordinated with divalent copper ion. The t hermal decomposition processes of the complexes show that the final residues are all cupper oxide. The results of indexes to the X-ray powder diffraction data indicate that the crystal structure of the complexes belong to monoclinic syste m, the lattice parameters are: a=0.6976nm,b=1.1546 nm,c=2.1689nm,a=96.80 1.7346nm3 for A; and a=0.7096nm,b=1.1359 nm,c=2.1002 nm,a=97.05nm3 for B, respectively.
