Spin-crossover (SCO) magnets can act as one of the most possible building blocks in molec- ular spintronics due to their magnetic bistability between the high-spin (HS) and low-spin (LS) states. Here, the electr...Spin-crossover (SCO) magnets can act as one of the most possible building blocks in molec- ular spintronics due to their magnetic bistability between the high-spin (HS) and low-spin (LS) states. Here, the electronic structures and transport properties through SCO magnet Fe(II)-N4S2 complexes sandwiched between gold electrodes are explored by performing exten- sive density functional theory calculations combined with non-equilibrium Green's function formalism. The optimized Fe-N and Fe-S distances and predicted magnetic moment of the SCO magnet Fe(II)-N4S2 complexes agree well with the experimental results. The reversed spin transition between the HS and LS states can be realized by visible light irradiation according to the estimated SCO energy barriers. Based on the obtained transport results, we observe nearly perfect spin-filtering effect in this SCO magnet Fe(II)-N4S2 junction with the HS state, and the corresponding current under small bias voltage is mainly contributed by the spin-down electrons, which is obviously larger than that of the LS case. Clearly, these theoretical findings suggest that SCO magnet Fe(II)-N4S2 complexes hold potential applications in molecular spintronies.展开更多
Properties of the triaxiai superdeformed (TSD) bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU...Properties of the triaxiai superdeformed (TSD) bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU(5)) symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia, and the spin of the TSD bands in Hf isotopes are obtained. It shows that this approach is quite powerful in describing the properties of the triaxial superdeformation in Hf isotopes.展开更多
A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer e...A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.展开更多
For an alcohol/water system and with fin baffle packing,continuous distillation experiments were carried out in a rotating packed bed(RPB)system at atmospheric pressure.The effects of the average high gravity factor(...For an alcohol/water system and with fin baffle packing,continuous distillation experiments were carried out in a rotating packed bed(RPB)system at atmospheric pressure.The effects of the average high gravity factor(β),liquid reflux ratio(R)and feedstock flux(F)on the momentum transfer and mass transfer were investigated. The gas phase pressure drop of RPB increased with the average high gravity factor,liquid reflux ratio and feedstock flux,which was 13.55-64.37 Pa atβof 2.01-51.49,R of 1.0-2.5,and F of 8-24 L·h1for a theoretical tray in the RPB with fin baffle packing.The investigation on the mass transfer in the RPB with different packings showed that the number of transfer units of RPB with a packing also increased with the average high gravity factor,reflux ratio and feedstock flux.It is found that the fin baffle packing(packing III)presents the best mass transfer performance and lowest pressure drop for the height equivalent to a theoretical plate(HETP),which is 6.59-9.84 mm.展开更多
The general relativistic frame dragging effect on the properties,such as the moments of inertia and the radiiof gyration of fast rotating neutron stars with a uniform strong magnetic field,is calculated accurate to th...The general relativistic frame dragging effect on the properties,such as the moments of inertia and the radiiof gyration of fast rotating neutron stars with a uniform strong magnetic field,is calculated accurate to the first orderin the uniform angular velocity.The results show that compared with the corresponding non-rotating static sphericalsymmetric neutron star with a weaker magnetic field,a fast rotating neutron star(millisecond pulsar)with a strongermagnetic field has a relative smaller moment of inertia and radius of gyration.展开更多
The rotating packed bed (RPB) with split packing is a novel gas-liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteri...The rotating packed bed (RPB) with split packing is a novel gas-liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteristics with adjacent rings in counter-rotation and co-rotation modes in a split packing RPB were studied experimentally. The physical absorption system NH3-H2O was used for characterizing the gas volumetric mass transfer coeffi- cient (kyae) and the effective inteffacial area (ae) was determined by chemical absorption in the CO2-NaOH sys- tem. The variation in kyae and ae with the operating conditions is also investigated. The experimental results indicated that kyae and ae for counter-rotation of the adjacent packing rings in the split packing RPB were higher than those for co-rotation, and both counter-rotation and co-rotation of the split packing RPB were superior over conventional RPBs under the similar ooerating conditions.展开更多
A statistical algorithm for the reconstruction from time sequence echocardiographic images is proposed in this paper. The ability to jointly restore the images and reconstruct the 3D images without blurring the bounda...A statistical algorithm for the reconstruction from time sequence echocardiographic images is proposed in this paper. The ability to jointly restore the images and reconstruct the 3D images without blurring the boundary is the main innovation of this algorithm. First, a Bayesian model based on MAP-MRF is used to reconstruct 3D volume, and extended to deal with the images acquired by rotation scanning method. Then, the spatiotemporal nature of ultrasound images is taken into account for the pa-rameter of energy function, which makes this statistical model anisotropic. Hence not only can this method reconstruct 3D ul-trasound images, but also remove the speckle noise anisotropically. Finally, we illustrate the experiments of our method on the synthetic and medical images and compare it with the isotropic reconstruction method.展开更多
Using the effective-field theory we studied the magnetic properties of a spin-1/2 Ising supedattice, which consist of three different ferromagnet materials. The magnetic behavior of this superlattice is examined. The ...Using the effective-field theory we studied the magnetic properties of a spin-1/2 Ising supedattice, which consist of three different ferromagnet materials. The magnetic behavior of this superlattice is examined. The critical temperature and the compensation temprature of the system are studied as a function of the exchange interactions between the nearest-neiboring spins across the interface and in the intraface. Temperature dependence of magenetizations is also given.展开更多
Spiral waves, whose rotation center can be regarded as a point defect, widely exist in various two-dimensional excitable systems. In this paper, by making use of Duan's topological current theory, we obtain the charg...Spiral waves, whose rotation center can be regarded as a point defect, widely exist in various two-dimensional excitable systems. In this paper, by making use of Duan's topological current theory, we obtain the charge density of spiral waves and the topological inner structure of its topological charge. The evolution of spiral wave is also studied from the topological properties of a two-dimensional vector field. The spiral waves are found generating or annihilating at the limit points and encountering, splitting, or merging at the bifurcation points of the two-dimensional vector field. Some applications of our theory are also discussed.展开更多
The critical properties of the planar rotator model with chiral Dzyaloshinsky-Moriya interaction are analyzed using a hybrid Monte Carlo method.Simulations on different lattices conform an observation that there is an...The critical properties of the planar rotator model with chiral Dzyaloshinsky-Moriya interaction are analyzed using a hybrid Monte Carlo method.Simulations on different lattices conform an observation that there is an XY-like Berezinskii-Kosterlitz-Thouless (BKT) phase transition in this model.The ground state and some thermodynamics properties are also discussed.展开更多
Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model (CSM) w...Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model (CSM) with the paring correlations treated by the particle-number-conserving (PNC) method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia (f^(1) and ,f^(2) versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f(1) with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6(5) keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189(1) keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 (1/2-[770]) orbital at the high spin leads to band-crossings at hω = 0.20 (hω~=0.25) MeV for the 7/2-[514]ω= -1/2 (ω= +1/2) band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.展开更多
基金supported by the National Natural Science Foundation of China(No.21473168 and No.11634011)the Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology
文摘Spin-crossover (SCO) magnets can act as one of the most possible building blocks in molec- ular spintronics due to their magnetic bistability between the high-spin (HS) and low-spin (LS) states. Here, the electronic structures and transport properties through SCO magnet Fe(II)-N4S2 complexes sandwiched between gold electrodes are explored by performing exten- sive density functional theory calculations combined with non-equilibrium Green's function formalism. The optimized Fe-N and Fe-S distances and predicted magnetic moment of the SCO magnet Fe(II)-N4S2 complexes agree well with the experimental results. The reversed spin transition between the HS and LS states can be realized by visible light irradiation according to the estimated SCO energy barriers. Based on the obtained transport results, we observe nearly perfect spin-filtering effect in this SCO magnet Fe(II)-N4S2 junction with the HS state, and the corresponding current under small bias voltage is mainly contributed by the spin-down electrons, which is obviously larger than that of the LS case. Clearly, these theoretical findings suggest that SCO magnet Fe(II)-N4S2 complexes hold potential applications in molecular spintronies.
基金supported by National Natural Science Foundation of China under Grant No. 10475026the Natural Science Foundation of Zhejiang Province under Grant No. KY607518
文摘Properties of the triaxiai superdeformed (TSD) bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU(5)) symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia, and the spin of the TSD bands in Hf isotopes are obtained. It shows that this approach is quite powerful in describing the properties of the triaxial superdeformation in Hf isotopes.
基金Supported by the National Natural Science Foundation of China(20821004 20990221) the National High Technology Research and Development Program of China(2006AA030202)+1 种基金 the Program for New Century Excellent Talents in University of China(NCET-07-0053) the National Basic Research Program of China(2009CB219903)
文摘A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20060110003)the Youth Science and Technology Research Fund of Shanxi Province(2008021009-1)the Development Project Fund for Colleges and Universities of Shanxi Province(20091127)
文摘For an alcohol/water system and with fin baffle packing,continuous distillation experiments were carried out in a rotating packed bed(RPB)system at atmospheric pressure.The effects of the average high gravity factor(β),liquid reflux ratio(R)and feedstock flux(F)on the momentum transfer and mass transfer were investigated. The gas phase pressure drop of RPB increased with the average high gravity factor,liquid reflux ratio and feedstock flux,which was 13.55-64.37 Pa atβof 2.01-51.49,R of 1.0-2.5,and F of 8-24 L·h1for a theoretical tray in the RPB with fin baffle packing.The investigation on the mass transfer in the RPB with different packings showed that the number of transfer units of RPB with a packing also increased with the average high gravity factor,reflux ratio and feedstock flux.It is found that the fin baffle packing(packing III)presents the best mass transfer performance and lowest pressure drop for the height equivalent to a theoretical plate(HETP),which is 6.59-9.84 mm.
基金National Natural Science Foundation of China under Grant Nos.10647116 and 10575140the China Postdoctoral Science Foundation under Grant No.2005037175
文摘The general relativistic frame dragging effect on the properties,such as the moments of inertia and the radiiof gyration of fast rotating neutron stars with a uniform strong magnetic field,is calculated accurate to the first orderin the uniform angular velocity.The results show that compared with the corresponding non-rotating static sphericalsymmetric neutron star with a weaker magnetic field,a fast rotating neutron star(millisecond pulsar)with a strongermagnetic field has a relative smaller moment of inertia and radius of gyration.
基金the National Natural Science Foundation of China(21376229,21206153)
文摘The rotating packed bed (RPB) with split packing is a novel gas-liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteristics with adjacent rings in counter-rotation and co-rotation modes in a split packing RPB were studied experimentally. The physical absorption system NH3-H2O was used for characterizing the gas volumetric mass transfer coeffi- cient (kyae) and the effective inteffacial area (ae) was determined by chemical absorption in the CO2-NaOH sys- tem. The variation in kyae and ae with the operating conditions is also investigated. The experimental results indicated that kyae and ae for counter-rotation of the adjacent packing rings in the split packing RPB were higher than those for co-rotation, and both counter-rotation and co-rotation of the split packing RPB were superior over conventional RPBs under the similar ooerating conditions.
基金Project supported by the National Basic Research Program (973) of0China (No. 2003CB716104), and Shanghai Science and TechnologyResearch Foundation (No. 034119820), China
文摘A statistical algorithm for the reconstruction from time sequence echocardiographic images is proposed in this paper. The ability to jointly restore the images and reconstruct the 3D images without blurring the boundary is the main innovation of this algorithm. First, a Bayesian model based on MAP-MRF is used to reconstruct 3D volume, and extended to deal with the images acquired by rotation scanning method. Then, the spatiotemporal nature of ultrasound images is taken into account for the pa-rameter of energy function, which makes this statistical model anisotropic. Hence not only can this method reconstruct 3D ul-trasound images, but also remove the speckle noise anisotropically. Finally, we illustrate the experiments of our method on the synthetic and medical images and compare it with the isotropic reconstruction method.
基金The project supported by Shanghai Leading Academic Discipline Project under Grant No. T0104
文摘Using the effective-field theory we studied the magnetic properties of a spin-1/2 Ising supedattice, which consist of three different ferromagnet materials. The magnetic behavior of this superlattice is examined. The critical temperature and the compensation temprature of the system are studied as a function of the exchange interactions between the nearest-neiboring spins across the interface and in the intraface. Temperature dependence of magenetizations is also given.
基金supported by National Natural Science Foundation of China and the Cuiying Programme of Lanzhou University
文摘Spiral waves, whose rotation center can be regarded as a point defect, widely exist in various two-dimensional excitable systems. In this paper, by making use of Duan's topological current theory, we obtain the charge density of spiral waves and the topological inner structure of its topological charge. The evolution of spiral wave is also studied from the topological properties of a two-dimensional vector field. The spiral waves are found generating or annihilating at the limit points and encountering, splitting, or merging at the bifurcation points of the two-dimensional vector field. Some applications of our theory are also discussed.
基金Supported by the Foundation of Hubei Department of Education under Grant No.Q20101602the National Natural Science Foundation of China under Grant No.11147180
文摘The critical properties of the planar rotator model with chiral Dzyaloshinsky-Moriya interaction are analyzed using a hybrid Monte Carlo method.Simulations on different lattices conform an observation that there is an XY-like Berezinskii-Kosterlitz-Thouless (BKT) phase transition in this model.The ground state and some thermodynamics properties are also discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.11275098 and 11275067)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model (CSM) with the paring correlations treated by the particle-number-conserving (PNC) method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia (f^(1) and ,f^(2) versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f(1) with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6(5) keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189(1) keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 (1/2-[770]) orbital at the high spin leads to band-crossings at hω = 0.20 (hω~=0.25) MeV for the 7/2-[514]ω= -1/2 (ω= +1/2) band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.