期刊文献+
共找到31篇文章
< 1 2 >
每页显示 20 50 100
欧元区的资本为什么会转向美国? 被引量:1
1
作者 孙立坚 谷耀 王培泽 《世界经济文汇》 CSSCI 北大核心 2005年第4期206-212,共7页
本文以欧元区近期的资本移动作为考察对象,首先对资本移动成因做了详细的文献综述,然后对欧元区自成立以来的资本移动现状做了考察,在此基础上通过对欧元区经济发展背景的分析来讨论欧元区资本流动转向美国的原因。本文的结论是近期欧... 本文以欧元区近期的资本移动作为考察对象,首先对资本移动成因做了详细的文献综述,然后对欧元区自成立以来的资本移动现状做了考察,在此基础上通过对欧元区经济发展背景的分析来讨论欧元区资本流动转向美国的原因。本文的结论是近期欧元区资本移动的驱动力主要来自于区内经济状况的下滑,即是“拉力”主宰了近期欧元区的资本移动。 展开更多
关键词 国际资本移动 欧元区 “引力”理论 欧元区经济 资本移动 美国 转向 考察对象 文献综述 资本流动
下载PDF
Light Propagation in the Second post-Newtonian Approximation of Scalar-Tensor Theory of Gravity 被引量:2
2
作者 DONG Peng LI Lei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第3期457-461,共5页
In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light... In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions. 展开更多
关键词 post-Newtonian approximation scalar-tensor theory light propagation
下载PDF
The Double Self—Dual Gravity with Cosmological Term and Constraints Under the Double Constant Conformal Transformation 被引量:1
3
作者 WUYa-Bo GUOYong-Xin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第6期663-666,共4页
The double constraint equations in the self-dual gravitational theory containing the cosmological term are derived in gravity. Furthermore, in order to deeply study the Lorentzian and Euclidean reality conditions for... The double constraint equations in the self-dual gravitational theory containing the cosmological term are derived in gravity. Furthermore, in order to deeply study the Lorentzian and Euclidean reality conditions for this theory, the relations between constraints are discussed by introducing the double constant conformal transformation and the double complex function method. 展开更多
关键词 self-dual gravity constraint equations conformal transformations reality conditions
下载PDF
Cosmological Constant and Stability of the Cosmological Models 被引量:1
4
作者 WANGYong-Jiu TANGZhi-Ming 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第6期667-670,共4页
The importance of cosmological constant for the cosmological models is given. The variations of the cosmological model for parameters and were discussed respectively. Near , the cosmological model is unstable with t... The importance of cosmological constant for the cosmological models is given. The variations of the cosmological model for parameters and were discussed respectively. Near , the cosmological model is unstable with the change of , and near , the cosmological model is unstable with the change of . So when we consider the stable cosmological model, we must consider the nonzero cosmological constant. 展开更多
关键词 COSMOLOGY cosmological models general relativity
下载PDF
Unified Theory of Fundamental Interactions 被引量:1
5
作者 WUNing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第5期561-568,共8页
Based on local gauge invariance, four different kinds of fundamental interactions in nature are unified in a theory which has Gravitational Gauge Group gauge symmetry. In this approach, gravitational field, like elec... Based on local gauge invariance, four different kinds of fundamental interactions in nature are unified in a theory which has Gravitational Gauge Group gauge symmetry. In this approach, gravitational field, like electromagnetic field, intermediate gauge field, and gluon field, is represented by gauge potential. Four kinds of fundamental interactions are formulated in the similar manner, and therefore can be unified in a direct or semi-direct product group. The model discussed in this paper is a renormalizable quantum model and can be regarded as an extension of the standard model to gravitational interactions, so it can be used to study quantum effects of gravitational interactions. 展开更多
关键词 unified field theories gauge field quantum gravity
下载PDF
Debye Entropic Force and Modified Newtonian Dynamics 被引量:1
6
作者 李昕 常哲 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第4期733-736,共4页
Verlinde has suggested that the gravity has an entropic origin, and a gravitational system could be regarded as a thermodynarnical system. It is well-known that the equipartition law of energy is invalid at very low t... Verlinde has suggested that the gravity has an entropic origin, and a gravitational system could be regarded as a thermodynarnical system. It is well-known that the equipartition law of energy is invalid at very low temperature. Therefore, entropic force should be modified while the temperature of the holographic screen is very low. It is shown that the modified entropic force is proportional to the square of the acceleration, while the temperature of the holographic screen is much lower than the Debye temperature TD. The modified entropic force returns to the Newton's law of gravitation while the temperature of the holographic screen is much higher than the Debye temperature. The modified entropic force is connected with modified Newtonian dynamics (MOND). The constant ao involved in MOND is linear in the Debye frequency WD, which can be regarded as the largest frequency of the bits in screen. We find that there do have a strong connection between MOND and cosmology in the framework of Verlinde's entropic force, if the holographic screen is taken to be bound of the Universe. The Debye frequency is linear in the Hubble constant Ho. 展开更多
关键词 entropic force modified Newtonian dynamics
下载PDF
Inconsistence of Non-Singular Spherically Symmetric Solution and a Satisfactory Energy-Momentum Complex
7
作者 Gamal G.L.Nashed 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第10期625-629,共5页
Two spherically symmetric non-singular black hole solutions in Moiler tetrad theory of gravitation have been obtained. Although the two solutions have the same form of metric (spherically symmetric nonsingular black ... Two spherically symmetric non-singular black hole solutions in Moiler tetrad theory of gravitation have been obtained. Although the two solutions have the same form of metric (spherically symmetric nonsingular black hole), their energy contents are different. We use another method given by Gibbons and Hawking to calculate the energy content of these solutions. We also obtained different value of energy. Study the requirements of a satisfactory energymomentum complex given by Moiler we find that the second solution, which behaves as 1/√r, is not transformed as a four-vector under Lorentz transformation. 展开更多
关键词 non-singular black hole solutions energy using Moiler complex energy using Gibbons and Hawking method Lorentz transformatio
下载PDF
Classification of Kantowski-Sachs and Bianchi Type Ⅲ Space-Times According to Their Killing Vector Fields in Teleparallel Theory of Gravitation
8
作者 Ghulam Shabbir Suhail Khan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第9期469-472,共4页
In this paper we classify Kantowski-Sachs and Bianchi type Ⅲ space-times according to their teleparallel Killing vector fields using direct integration technique. It turns out that the dimension of the telepaxallel K... In this paper we classify Kantowski-Sachs and Bianchi type Ⅲ space-times according to their teleparallel Killing vector fields using direct integration technique. It turns out that the dimension of the telepaxallel Killing vector fields are 4 or 6, which are the same in numbers as in general relativity. In case of 4 the teleparallel Killing vector fields are multiple of the corresponding Killing vector fields in general relativity by some function of t. In the case of 6 Killing vector fields the metric functions become constants and the Killing vector fields in this case are exactly the same as in general relativity. Here we also discuss the Lie algebra in each case. 展开更多
关键词 teleparallel killing vector fields Weitzenb5ck connections TORSION
下载PDF
Reconstructing Equation of State for Dark Energy in Double Complex Symmetric Gravitational Theory
9
作者 SHAO Ying GUI Yuan-Xing WANG Wei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第6期1148-1152,共5页
We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory (DCSGT). The universe we live in is taken as the real part of the whole spacetime MC^4(J), which ... We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory (DCSGT). The universe we live in is taken as the real part of the whole spacetime MC^4(J), which is double complex. By introducing the spatially flat FRW metric, not only the double Friedmann equations but also the two constraint conditions py = 0 and J^2 = 1 are obtained. Farthermore, using parametric DL(z) ansatz, we reconstruct the ω/(z) and V(Ф) for dark energy from real observational data. We find that in the two cases of J = i, pJ = 0, and J = ε, pJ≠0, the corresponding equations of state ω'(z) remain close to -1 at present (z = 0) and change from below -1 to above -1. The results illustrate that the whole spacetime, i.e. the double complex spacetime MC^4(J), may be either ordinary complex (J = i, pJ = 0) or hyperbolic complex (J = ε, pJ≠ 0). And the fate of the universe would be Big Rip in the future. 展开更多
关键词 double complex symmetric gravitational theory equation of state dark energy
下载PDF
Two-Flux Colliding Plane Waves in String Theory
10
作者 CHEN Bin ZHANG Jun-Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3X期463-472,共10页
We construct the two-flux colliding plane wave solutions in higher-dimensional gravity theory with dilaton,and two complementary fluxes. Two kinds of solutions have been obtained: Bell-Szekeres (BS) type and homogeneo... We construct the two-flux colliding plane wave solutions in higher-dimensional gravity theory with dilaton,and two complementary fluxes. Two kinds of solutions have been obtained: Bell-Szekeres (BS) type and homogeneous type. After imposing the junction condition, we find that only the BS type solution is physically well-defined. Furthermore, we show that the future curvature singularity is always developed for our solutions. 展开更多
关键词 colliding plane wave string theory
下载PDF
Classification of Teleparallel Homothetic Vector Fields in Cylindrically Symmetric Static Space-Times in Teleparallel Theory of Gravitation
11
作者 Ghulam Shabbir Suhail Khan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第10期675-678,共4页
In this paper we classify cylindrically symmetric static space-times according to their teleparallel homothetic vector fields using direct integration technique. It turns out that the dimensions of the teleparallel ho... In this paper we classify cylindrically symmetric static space-times according to their teleparallel homothetic vector fields using direct integration technique. It turns out that the dimensions of the teleparallel homothetic vector fields are 4, 5, 7 or 11, which are the same in numbers as in general relativity. In case of 4, 5 or 7 proper teleparallel homothetic vector fields exist for the special choice to the space-times. In the case of 11 teleparallel homothetic vector fields the space-time becomes Minkowski with all the zero torsion components. Teleparallel homothetic vector fields in this case are exactly the same as in general relativity. It is important to note that this classification also covers the plane symmetric static space-times. 展开更多
关键词 teleparallel homothetic vector fields WeitzenbSck connections TORSION
下载PDF
A Note on Classification of Spatially Homogeneous Rotating Space-Times According to Their Teleparallel Killing Vector Fields in Teleparallel Theory of Gravitation
12
作者 Ghulam Shabbir Suhail Khan Amjad Ali 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第2期268-272,共5页
In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique.It turns out that the dimension of the teleparallel Killing... In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique.It turns out that the dimension of the teleparallel Killing vector fields is 5 or 10.In the case of 10 teleparallel Killing vector fields the space-time becomes Minkowski and all the torsion components are zero.Teleparallel Killing vector fields in this case are exactly the same as in general relativity.In the cases of 5 teleparallel Killing vector fields we get two more conservation laws in the teleparallel theory of gravitation.Here we also discuss some well-known examples of spatially homogeneous rotating space-times according to their teleparallel Killing vector fields. 展开更多
关键词 teleparallel killing vector fields Weitzenbock geometry TORSION
下载PDF
The kinematics modeling based on Spinor theory for CT-guided hybrid robot 被引量:2
13
作者 唐粲 《High Technology Letters》 EI CAS 2009年第1期20-25,共6页
This paper focused on a simplified method for solving the hybrid robot kinematics in CT-guided (computerized tomography, CT) surgery. By position constraint introduced, the hybrid robot can be transformed as a redun... This paper focused on a simplified method for solving the hybrid robot kinematics in CT-guided (computerized tomography, CT) surgery. By position constraint introduced, the hybrid robot can be transformed as a redundant serial 7-DOF robot. The forward displacement calculation was developed based on the product-of-exponential formula (POE). Because of the kinematics complexity of the hybrid and redundant robot, the combination technique of Ulrich two-step iteration method and paul variables detachment method (UTI-PVD) was introduced to fulfill the inverse kinematics of redundant robot, the novelty of which lay in the flexibility of various robots structures and in high calculation efficiency for realtime control. The process of solving the inverse displacement was analyzed. The UTI-PVD method can be applicable to kinematics of many robots, especially for redundant robots with more than 6DOF. The kinematics simulation was provided, and robot dexterity analysis was presented. The results indicated that the hybrid robot could implement the minimally invasive CT-guided surgery. 展开更多
关键词 CT-guided surgery hybrid robot KINEMATICS product-of-exponential formula UTIPVD method
下载PDF
A New Solution with Torsion in Model of dS Gauge Theory of Gravity
14
作者 黄超光 马孟森 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第1期65-68,共4页
A new static de Sitter solution with torsion in the model of de Sitter gauge theory of gravity is obtained. The torsion only contains Q(3)-symmetric tensor part according to irreducible decomposition. Some propertie... A new static de Sitter solution with torsion in the model of de Sitter gauge theory of gravity is obtained. The torsion only contains Q(3)-symmetric tensor part according to irreducible decomposition. Some properties of the new solution are discussed. 展开更多
关键词 static dS solution with torsion model dS gauge theory of gravity tensor part of torsion
下载PDF
Schwarzschild-de-Sitter Solution in Quantum Gauge Theory of Gravity
15
作者 Gheorghe Zet Camelia Popa Doina Partenie 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5期843-846,共4页
We use the theory based on the gravitational gauge group G to obtain a spherical symmetric solution of the field equations for the gravitational potentials on a Minkowski space-time. The gauge group G is defined and t... We use the theory based on the gravitational gauge group G to obtain a spherical symmetric solution of the field equations for the gravitational potentials on a Minkowski space-time. The gauge group G is defined and then we introduce the gauge-covariant derivative Dμ. The strength tensor of the gravitational gauge field is also obtained and a gauge-invariant Lagrangian including the cosmological constant is constructed. A model whose gravitational gauge potentials A^α μ (x) have spherical symmetry, depending only on the radial coordinate τ is considered and an analytical solution of these equations, which induces the Schwarzschild-de-Sitter metric on the gauge group space, is then determined. All the calculations have been performed by GR Tensor II computer algebra package, running on the Maple V platform, along with several routines that we have written for our model. 展开更多
关键词 gauge theory gravitational field spherical symmetry
下载PDF
Increase in Probability of the Correct Forecast of Tsunami Formation
16
作者 V.I. Korochentsev E.V. Lisunov P.P. Sherbakov 《Journal of Environmental Science and Engineering》 2011年第6期716-719,共4页
The presented paper exhibits theory of the "gravitational" waves propagation near the Earth surface and in the ocean. There was determined an expression "gravitational" wave which was registered by the gravimeters... The presented paper exhibits theory of the "gravitational" waves propagation near the Earth surface and in the ocean. There was determined an expression "gravitational" wave which was registered by the gravimeters being placed in several points of the Earth globe. Alteration of gravitational field was accompanied by alteration of the "gravitational" wave which has the velocity differing from the velocity of seismic waves. The theoretical model was proved by many experiments realized under registration of the underwater earthquake core by tens of gravimeters being placed in the Earth globe different points. The "gravitational" waves assist to increase the right forecast probability of the beginning tsunami to 50%. 展开更多
关键词 TSUNAMI EARTHQUAKE gravitational waves tsunami forecast.
下载PDF
Axial Anomaly for Eguchi-Hanson Metrics with Nonzero Total Mass
17
作者 ZHANGXiao ZHANGYao-Zhong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第1期79-80,共2页
We compute the Dirac indexes for the two spin structures κ_0 and κ_1 forEguchi-Hanson metrics with nonzero total mass. It shows that the Dirac indexes do not vanish ingeneral, and axial anomaly exists. When the metr... We compute the Dirac indexes for the two spin structures κ_0 and κ_1 forEguchi-Hanson metrics with nonzero total mass. It shows that the Dirac indexes do not vanish ingeneral, and axial anomaly exists. When the metric has zero total mass, the Dirac index vanishes forthe spin structure κ_0 , and no axial anomaly exists in this case. 展开更多
关键词 axial anomaly eguchi-hanson metric total mass
下载PDF
Frame Dragging Effect on Properties of Rotating Neutron Stars with Strong Magnetic Field
18
作者 GUO Yu-Wu WEN De-Hua HU Jian-Xun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第12期1469-1472,共4页
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
关键词 rotating neutron star frame dragging effect moment of inertia magnetic field
下载PDF
Gravitational Field Excitation from the First Term of Quantum Wilson Loop
19
作者 SHAO Liang SHAO Dan +2 位作者 SHAO Chang-Gui H. Noda CHEN Yi-Han 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期77-86,共10页
In 4-dimensional R-gravity, using the linear and square terms of the expanding expression of the space-time connection, we calculate the possible curvature excitation (order k^4) of gravitational field, which is giv... In 4-dimensional R-gravity, using the linear and square terms of the expanding expression of the space-time connection, we calculate the possible curvature excitation (order k^4) of gravitational field, which is given by the first term of quantum Wilson loop (w) through two-point Green's function of the connection. At the same time using the tree diagram propagators of gravitons, the lowest order (k^4) correction to (w) is also calculated through the graviton self-energy in the term. Under the accuracy condition up to order k^4, we have obtained a complete expression of the excitation contributed from the leading term (w^(2))of (w). 展开更多
关键词 excitation of gravitational field graviton self-energy correction complete expression of excitation of order k^4 in (w^(2))
下载PDF
Dilaton Black Hole Tunneling Radiation in de Sitter Universe
20
作者 LI Gu-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第3期453-454,共2页
The Hawking radiation via tunneling from the dilaton black hole in de Sitter universe is investigated using Parikh Wilczek's method. We show that if the self-gravitational interaction and energy conservation are take... The Hawking radiation via tunneling from the dilaton black hole in de Sitter universe is investigated using Parikh Wilczek's method. We show that if the self-gravitational interaction and energy conservation are taken into account, the modified radiation spectrum deviates from exact thermal spectrum and satisfies the unitary theory. 展开更多
关键词 tunneling radiation de Sitter universe dilaton black hole
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部