By the fractal dimension method, the polaron properties in cylindrical GaAs/AlxGa1-xAs core-shell nanowire are explored. In this study, the polaron effects in GaAs/AlxGa1-xAs core-shell nanowire at different values of...By the fractal dimension method, the polaron properties in cylindrical GaAs/AlxGa1-xAs core-shell nanowire are explored. In this study, the polaron effects in GaAs/AlxGa1-xAs core-shell nanowire at different values of shell width and aluminum concentration are discussed. The polaron binding energy, polaron mass shift and fractal dimension parameter are numerically worked out each as a function of core radius. The calculation results show that the binding energy and mass shift of the polaron first increase and then decrease as the core radius increases, forming their corresponding maximum values for different aluminum concentrations at a given shell width. Polaron problems in the cylindrical GaAs/AlxGa1-xAs core-shell nanowire are solved simply by using the fractal dimension method to avoid complex and lengthy calculations.展开更多
Sandwich construction incorporating a honeycomb cellular core offers the attainment of structures that are very stiff and strong in bending while the weight is kept at a minimum. Generally, an aluminum or Nomex honeyc...Sandwich construction incorporating a honeycomb cellular core offers the attainment of structures that are very stiff and strong in bending while the weight is kept at a minimum. Generally, an aluminum or Nomex honeycomb core is used in applications requiring sandwich construction with fiber-reinforced composite facesheets. However, the use of a fiber-reinforced composite core offers the potential for even lower weight, increased stiffness and strength, low thermal distortion compatible with that of the facesheets, the absence of galvanic corrosion and the ability to readily modify the core properties to suit specialized needs. Furthermore, the material of the core itself will exhibit anisotropic material properties in this case. In order to design, analyze and optimize these structures, knowledge of the effective mechanical properties of the core is essential. In this paper, the effective three-dimensional mechanical properties of a composite hexagonal cell core are determined using a numerical method based on a finite element analysis of a representative unit cell. In particular, the geometry of the simplest repeating unit of the core as well as the appropriate loading and boundary conditions that must be applied is presented.展开更多
Based on the generalized uncertainty principle with maximum momentum arid minimal length, we discuss the equation of state of ideal ultra-relativistic Fermi gases at zero temperature. Maximum momentum avoids the probl...Based on the generalized uncertainty principle with maximum momentum arid minimal length, we discuss the equation of state of ideal ultra-relativistic Fermi gases at zero temperature. Maximum momentum avoids the problem that the Fermi degenerate pressure blows up since the increase of the Fermi energy is not limited. Applying this equation of state to the Tolman-Oppenheimer Volkoff （TOV） equation, the quantum gravitational effects on the cores of compact stars are discussed. In the center of compact stars, we obtain the singularity-free solution of the metric component, gtt ～-（1 ＋ 0.2185×r^2）. By numerically solving the TOV equation, we find that quantum gravity plays an important role in the region r～10^4α0（△x）min. Current observed masses of neutron stars indicate that the dimensionless parameter α0 cannot exceed 10^19.展开更多
The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters （core structure, fuel assembly component） by using the Monte Carlo method....The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters （core structure, fuel assembly component） by using the Monte Carlo method. The obtained values of Keff are compared and analysed, which can provide theoretical basis for reactor design.展开更多
Memory effect has been studied in the system using magnetic nanoparticles with Ni nanocore encapsulated by non-magnetic and oxidation-resistant Ni2P nanoshell acquired through surface-phosphatizing Ni nanoparticles. T...Memory effect has been studied in the system using magnetic nanoparticles with Ni nanocore encapsulated by non-magnetic and oxidation-resistant Ni2P nanoshell acquired through surface-phosphatizing Ni nanoparticles. The self-assembled array with interparticle spacing of about 6 nm shows memory effect up to 200 K below its average blocking temperature of 260 K. And reducing the interparticle spacing of the self-assembled array via annealing can further enlarge the temperature range of memory effect up to room-temperature. The memory effect can be understood based on the thermal relaxation theory of single-domain magnetic nanoparticles. Furthermore, the read-write magnetic coding is realized based on the temperature changes, using the memory effect up to room-temperature, which may be useful for future memory devices.展开更多
Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the...Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the bundleeffect was affected considerably by processing conditions(applied pressure and processing time).The boundaryof the bundles was disappeared under suitable processingconditions and finally an even fiber/resin distributioncould be attained.In consolidation,filament bundlesgetting close each other and resin flowing into the bundl-es occurred simultaneously,and eventually the bundleswere fully impregnated by the resin.Fiber packing den-sity in UD-laminate was the same as that of frictionspun core yarn(55%-65% in volume)and was not af-fected significantly by processing conditions under thecurrent experimental conditions.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10574011 and 10974017)
文摘By the fractal dimension method, the polaron properties in cylindrical GaAs/AlxGa1-xAs core-shell nanowire are explored. In this study, the polaron effects in GaAs/AlxGa1-xAs core-shell nanowire at different values of shell width and aluminum concentration are discussed. The polaron binding energy, polaron mass shift and fractal dimension parameter are numerically worked out each as a function of core radius. The calculation results show that the binding energy and mass shift of the polaron first increase and then decrease as the core radius increases, forming their corresponding maximum values for different aluminum concentrations at a given shell width. Polaron problems in the cylindrical GaAs/AlxGa1-xAs core-shell nanowire are solved simply by using the fractal dimension method to avoid complex and lengthy calculations.
文摘Sandwich construction incorporating a honeycomb cellular core offers the attainment of structures that are very stiff and strong in bending while the weight is kept at a minimum. Generally, an aluminum or Nomex honeycomb core is used in applications requiring sandwich construction with fiber-reinforced composite facesheets. However, the use of a fiber-reinforced composite core offers the potential for even lower weight, increased stiffness and strength, low thermal distortion compatible with that of the facesheets, the absence of galvanic corrosion and the ability to readily modify the core properties to suit specialized needs. Furthermore, the material of the core itself will exhibit anisotropic material properties in this case. In order to design, analyze and optimize these structures, knowledge of the effective mechanical properties of the core is essential. In this paper, the effective three-dimensional mechanical properties of a composite hexagonal cell core are determined using a numerical method based on a finite element analysis of a representative unit cell. In particular, the geometry of the simplest repeating unit of the core as well as the appropriate loading and boundary conditions that must be applied is presented.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No ZYGX2009X008
文摘Based on the generalized uncertainty principle with maximum momentum arid minimal length, we discuss the equation of state of ideal ultra-relativistic Fermi gases at zero temperature. Maximum momentum avoids the problem that the Fermi degenerate pressure blows up since the increase of the Fermi energy is not limited. Applying this equation of state to the Tolman-Oppenheimer Volkoff （TOV） equation, the quantum gravitational effects on the cores of compact stars are discussed. In the center of compact stars, we obtain the singularity-free solution of the metric component, gtt ～-（1 ＋ 0.2185×r^2）. By numerically solving the TOV equation, we find that quantum gravity plays an important role in the region r～10^4α0（△x）min. Current observed masses of neutron stars indicate that the dimensionless parameter α0 cannot exceed 10^19.
基金Project supported by the National Natural Science Foundation of China(Grant No10647109)
文摘The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters （core structure, fuel assembly component） by using the Monte Carlo method. The obtained values of Keff are compared and analysed, which can provide theoretical basis for reactor design.
基金Funded by the National Natural Science Foundation of China(No.11174092)
文摘Memory effect has been studied in the system using magnetic nanoparticles with Ni nanocore encapsulated by non-magnetic and oxidation-resistant Ni2P nanoshell acquired through surface-phosphatizing Ni nanoparticles. The self-assembled array with interparticle spacing of about 6 nm shows memory effect up to 200 K below its average blocking temperature of 260 K. And reducing the interparticle spacing of the self-assembled array via annealing can further enlarge the temperature range of memory effect up to room-temperature. The memory effect can be understood based on the thermal relaxation theory of single-domain magnetic nanoparticles. Furthermore, the read-write magnetic coding is realized based on the temperature changes, using the memory effect up to room-temperature, which may be useful for future memory devices.
文摘Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the bundleeffect was affected considerably by processing conditions(applied pressure and processing time).The boundaryof the bundles was disappeared under suitable processingconditions and finally an even fiber/resin distributioncould be attained.In consolidation,filament bundlesgetting close each other and resin flowing into the bundl-es occurred simultaneously,and eventually the bundleswere fully impregnated by the resin.Fiber packing den-sity in UD-laminate was the same as that of frictionspun core yarn(55%-65% in volume)and was not af-fected significantly by processing conditions under thecurrent experimental conditions.
