The (2+1)-dimensional Maxwell-Chern-Simons gravity with phantom dilaton field coupling is studied in this paper.It is shown that black hole solution to exist when electromagnetic coupled to dilaton field in the non-tr...The (2+1)-dimensional Maxwell-Chern-Simons gravity with phantom dilaton field coupling is studied in this paper.It is shown that black hole solution to exist when electromagnetic coupled to dilaton field in the non-trivial way.Moreover,asymptotic index and distribution parameter of current density are calculated by using black hole solution,some new features of this solution are briefly discussed.展开更多
This paper studies phantom linear scalar field （LSF） and phantom non-linear Born-Infeld （NLBI） scalar field with square potential of the form V（Ф） =1/2m^2Ф^2. The equation of state parameter w（z）, and evolut...This paper studies phantom linear scalar field （LSF） and phantom non-linear Born-Infeld （NLBI） scalar field with square potential of the form V（Ф） =1/2m^2Ф^2. The equation of state parameter w（z）, and evolution of scale factor a（t） in both phantom LSF and phantom NLBI scalar model are explored. The age of universe Hot and the transition redshift Z are obtained. The Gold data set of 157-SN-Ia is used to constrain parameters of the two models by numerical calculation. The phantom LSF is slightly better than the phantom NLBI type scalar field model for a large m. Although a smaller m corresponding to a slower rolling of field Ф better fits the observation data, the difference between phantom NLBI scalar field and phantom LSF is not distinct in this case.展开更多
This paper reviews the development of f(R) gravity theory and Phantom and Quintessence fields. Specifically, we present a new general action of f(R) gravity and Phantom and Quintessence fields coupled to scalar curvat...This paper reviews the development of f(R) gravity theory and Phantom and Quintessence fields. Specifically, we present a new general action of f(R) gravity and Phantom and Quintessence fields coupled to scalar curvature. Then, we deduce Euler-Lagrange Equations of different fields, matter tensor and effective matter tensor. Additionally, this paper obtains the general pressure, density and speed sound of the new general field action, and investigates different cosmological evolutions with inflation. Further, this paper investigates a general f(R) gravity theory with a general matter action and obtains the different field equations, general matter tensor and effective matter tensor. Besides, this paper obtains the effective Strong Energy Condition (SEC) and effective Null Energy Condition (NEC). Then, we prove that when f(R) approaches to R, the effective SEC and the effective NEC approach to the usual SEC and the usual NEC, respectively. Finally, this paper presents a general action of f(R) gravity, Quintessence and Phantom fields and their applications.展开更多
We present the Empirical Formula (EF) to calculate the phantom scatter factor, S<sub>p</sub>, of small radiation fields under charge particle dis-equilibrium conditions. The Empirical Formula (EF) was veri...We present the Empirical Formula (EF) to calculate the phantom scatter factor, S<sub>p</sub>, of small radiation fields under charge particle dis-equilibrium conditions. The Empirical Formula (EF) was verified by examining the calculated data with experimentally measured data utilizing the anthropomorphic phantom in twelve different combinations of beam entry and point location, where the value for S<sub>p</sub> per tissue composition was within 3% in 8/12 cases, 5% in 1/12 cases, and 10% in 3/12 cases. Our results showed a good agreement with experimental data to less than 1% when the ion chamber was surrounded by the homogeneous tissue, whether lung, soft tissue, or bone. Indicating that the prediction of the equation is valid, and it can be reliably used for phantom scatter factor calculation for different homogeneous media under charge particle dis- equilibrium conditions.展开更多
We investigate the phantom dark energy model derived from the scalar field with a negative kinetic term. By assuming a particular relation between the time derivative of the phantom field and the Hubble function, an e...We investigate the phantom dark energy model derived from the scalar field with a negative kinetic term. By assuming a particular relation between the time derivative of the phantom field and the Hubble function, an exact solution of the model is constructed. Absence of the ＇big rip＇ singularity is shown explicitly. We then derive special features of phantom dark energy model and show that its predictions are consistent with all astrophysical observations.展开更多
Abstract: The aim of this study was to develop a cheap, locally made and friendly applicable phantom for gamma camera quality control and to test its validity relative to standard results (intrinsic and extrinsic spat...Abstract: The aim of this study was to develop a cheap, locally made and friendly applicable phantom for gamma camera quality control and to test its validity relative to standard results (intrinsic and extrinsic spatial linearity and intrinsic and extrinsic uniformity) of gamma camera SPECT. And the significance of this experimental study was to introduce a multi-purpose phantom for gamma camera which could overcome the risk accompanied by quality control test procedure such as detector crystal damage and the appearance of moiré patterns. The results of the developed phantom showed an average count difference of 0.7% relative to the standard phantom and about 4% in X- to Y-axis directions relative to the standard phantom. Also, the measured absolute linearity was 0.63 mm in X direction and 0.64 mm in Y direction for the UFOV compare with 0.70 mm value of acceptance test. And the I.U. and D.U. of the developed phantom were 3.18% and 2.27% respectively for the UFOV relative to the standard phantom I.U. and D.U. (2.0% and 1.5%) for the UFOV respectively.展开更多
基金Supported by Natural Science Foundation of Sichuan Education Committee under Grant No. 11ZA100Scientific Research Foundation for Graduate Student of Sichuan Normal University under Grant No. 20113
文摘The (2+1)-dimensional Maxwell-Chern-Simons gravity with phantom dilaton field coupling is studied in this paper.It is shown that black hole solution to exist when electromagnetic coupled to dilaton field in the non-trivial way.Moreover,asymptotic index and distribution parameter of current density are calculated by using black hole solution,some new features of this solution are briefly discussed.
基金Project supported by the National Natural Science Foundation of China （Grant Nos.10573012, 10575068）, and the Shanghai Municipal Science and Technology Commission （Grant No.04dz05905）
文摘This paper studies phantom linear scalar field （LSF） and phantom non-linear Born-Infeld （NLBI） scalar field with square potential of the form V（Ф） =1/2m^2Ф^2. The equation of state parameter w（z）, and evolution of scale factor a（t） in both phantom LSF and phantom NLBI scalar model are explored. The age of universe Hot and the transition redshift Z are obtained. The Gold data set of 157-SN-Ia is used to constrain parameters of the two models by numerical calculation. The phantom LSF is slightly better than the phantom NLBI type scalar field model for a large m. Although a smaller m corresponding to a slower rolling of field Ф better fits the observation data, the difference between phantom NLBI scalar field and phantom LSF is not distinct in this case.
文摘This paper reviews the development of f(R) gravity theory and Phantom and Quintessence fields. Specifically, we present a new general action of f(R) gravity and Phantom and Quintessence fields coupled to scalar curvature. Then, we deduce Euler-Lagrange Equations of different fields, matter tensor and effective matter tensor. Additionally, this paper obtains the general pressure, density and speed sound of the new general field action, and investigates different cosmological evolutions with inflation. Further, this paper investigates a general f(R) gravity theory with a general matter action and obtains the different field equations, general matter tensor and effective matter tensor. Besides, this paper obtains the effective Strong Energy Condition (SEC) and effective Null Energy Condition (NEC). Then, we prove that when f(R) approaches to R, the effective SEC and the effective NEC approach to the usual SEC and the usual NEC, respectively. Finally, this paper presents a general action of f(R) gravity, Quintessence and Phantom fields and their applications.
文摘We present the Empirical Formula (EF) to calculate the phantom scatter factor, S<sub>p</sub>, of small radiation fields under charge particle dis-equilibrium conditions. The Empirical Formula (EF) was verified by examining the calculated data with experimentally measured data utilizing the anthropomorphic phantom in twelve different combinations of beam entry and point location, where the value for S<sub>p</sub> per tissue composition was within 3% in 8/12 cases, 5% in 1/12 cases, and 10% in 3/12 cases. Our results showed a good agreement with experimental data to less than 1% when the ion chamber was surrounded by the homogeneous tissue, whether lung, soft tissue, or bone. Indicating that the prediction of the equation is valid, and it can be reliably used for phantom scatter factor calculation for different homogeneous media under charge particle dis- equilibrium conditions.
文摘We investigate the phantom dark energy model derived from the scalar field with a negative kinetic term. By assuming a particular relation between the time derivative of the phantom field and the Hubble function, an exact solution of the model is constructed. Absence of the ＇big rip＇ singularity is shown explicitly. We then derive special features of phantom dark energy model and show that its predictions are consistent with all astrophysical observations.
文摘Abstract: The aim of this study was to develop a cheap, locally made and friendly applicable phantom for gamma camera quality control and to test its validity relative to standard results (intrinsic and extrinsic spatial linearity and intrinsic and extrinsic uniformity) of gamma camera SPECT. And the significance of this experimental study was to introduce a multi-purpose phantom for gamma camera which could overcome the risk accompanied by quality control test procedure such as detector crystal damage and the appearance of moiré patterns. The results of the developed phantom showed an average count difference of 0.7% relative to the standard phantom and about 4% in X- to Y-axis directions relative to the standard phantom. Also, the measured absolute linearity was 0.63 mm in X direction and 0.64 mm in Y direction for the UFOV compare with 0.70 mm value of acceptance test. And the I.U. and D.U. of the developed phantom were 3.18% and 2.27% respectively for the UFOV relative to the standard phantom I.U. and D.U. (2.0% and 1.5%) for the UFOV respectively.
