We investigate the unified first law and the generalized second law in a modified holographic dark energy model. The thermodynamical analysis on the apparent horizon can work and the corresponding entropy formula is e...We investigate the unified first law and the generalized second law in a modified holographic dark energy model. The thermodynamical analysis on the apparent horizon can work and the corresponding entropy formula is extracted from the systematic algorithm. The entropy correction term depends on the extra-dimension number of the brane as expected, but the interplay between the correction term and the extra dimensions is more complicated. With the unified first law of thermodynamics well-founded, the generalized second law of thermodynamics is discussed and it is found that the second law can be violated in certain circumstances. Particularly, if the number of the extra dimensions is larger than one, the generalized law of thermodynamics is always satisfied; otherwise, the validity of the second law can only be guaranteed with the Hubble radius greatly smaller than the crossover scale rcof the 5-dimensional DGP model.展开更多
The possibility of a description of the fundamental interactions of physics, including gravitation, based upon the assumption of 6 real extra dimensions is presented. The usual 4-dimension space-time, a curved surface...The possibility of a description of the fundamental interactions of physics, including gravitation, based upon the assumption of 6 real extra dimensions is presented. The usual 4-dimension space-time, a curved surface with the Lorentz group as local symmetry, is embedded in a larger flat 10-dimension space. Through a fundamental assumption about the geometry of the orthogonal 6-d space in every point of the 4-d surface, there are two possibilities for classifying the physical states, corresponding to two types of particles: 1) hadrons, experiencing a gauge field associated to a real symmetry group GH(6), isomorphous to SU(3), which is identified with the strong interaction, and 2) leptons experiencing another gauge field associated with a real symmetry group GL(6), isomorphous to SU(2) × U(1) but different from the usual electroweak coupling. In addition, both hadrons and leptons are subject to weak and electromagnetic interactions plus a scalar BEH-like coupling, with the respective real symmetries SO(3), SO(2), SO(1), isomorphous to SU(2), U(1), I(1). This description can be extended so as to include gravitation;postulating a minimal Lagrangian in the full 10-d space, the equations of motion are derived. They imply the existence of a set of additional vector-type fields which do not act the same way upon hadrons and leptons, thus inducing a violation of the equivalence principle.展开更多
特高压交流输变电工程输送距离长,建设规模大,施工安全风险大,文明施工和环保水保要求高,建设管理难度增大。本文以淮南-南京-上海1 000 k V交流特高压工程为例,集成应用地理信息系统、三维可视化和IT等技术,对施工现场实施无人机航摄,...特高压交流输变电工程输送距离长,建设规模大,施工安全风险大,文明施工和环保水保要求高,建设管理难度增大。本文以淮南-南京-上海1 000 k V交流特高压工程为例,集成应用地理信息系统、三维可视化和IT等技术,对施工现场实施无人机航摄,开展特高压工程施工安全管控系统研究[1-6],实现施工现场的安全、质量、环保水保和通道清理信息的管控,使建设管理人员全面地掌握施工现场信息,进一步提高基建管理水平。展开更多
基金Supported by National Foundation of China under Grant Nos.10747155 and 11205131the Ministry of Science and Technology of the National Natural Science Foundation of China key project under Grant Nos.11175270,11005164,11073005,and 10935013Chongqing Science and Technology Commission under Grant No.2010BB0408
文摘We investigate the unified first law and the generalized second law in a modified holographic dark energy model. The thermodynamical analysis on the apparent horizon can work and the corresponding entropy formula is extracted from the systematic algorithm. The entropy correction term depends on the extra-dimension number of the brane as expected, but the interplay between the correction term and the extra dimensions is more complicated. With the unified first law of thermodynamics well-founded, the generalized second law of thermodynamics is discussed and it is found that the second law can be violated in certain circumstances. Particularly, if the number of the extra dimensions is larger than one, the generalized law of thermodynamics is always satisfied; otherwise, the validity of the second law can only be guaranteed with the Hubble radius greatly smaller than the crossover scale rcof the 5-dimensional DGP model.
文摘The possibility of a description of the fundamental interactions of physics, including gravitation, based upon the assumption of 6 real extra dimensions is presented. The usual 4-dimension space-time, a curved surface with the Lorentz group as local symmetry, is embedded in a larger flat 10-dimension space. Through a fundamental assumption about the geometry of the orthogonal 6-d space in every point of the 4-d surface, there are two possibilities for classifying the physical states, corresponding to two types of particles: 1) hadrons, experiencing a gauge field associated to a real symmetry group GH(6), isomorphous to SU(3), which is identified with the strong interaction, and 2) leptons experiencing another gauge field associated with a real symmetry group GL(6), isomorphous to SU(2) × U(1) but different from the usual electroweak coupling. In addition, both hadrons and leptons are subject to weak and electromagnetic interactions plus a scalar BEH-like coupling, with the respective real symmetries SO(3), SO(2), SO(1), isomorphous to SU(2), U(1), I(1). This description can be extended so as to include gravitation;postulating a minimal Lagrangian in the full 10-d space, the equations of motion are derived. They imply the existence of a set of additional vector-type fields which do not act the same way upon hadrons and leptons, thus inducing a violation of the equivalence principle.
文摘特高压交流输变电工程输送距离长,建设规模大,施工安全风险大,文明施工和环保水保要求高,建设管理难度增大。本文以淮南-南京-上海1 000 k V交流特高压工程为例,集成应用地理信息系统、三维可视化和IT等技术,对施工现场实施无人机航摄,开展特高压工程施工安全管控系统研究[1-6],实现施工现场的安全、质量、环保水保和通道清理信息的管控,使建设管理人员全面地掌握施工现场信息,进一步提高基建管理水平。
