We study the ordinary differential equations related to rotationally symmetric pseudo-Khler metricsof constant scalar curvatures. We present various solutions on various holomorphic line bundles over projectivespaces ...We study the ordinary differential equations related to rotationally symmetric pseudo-Khler metricsof constant scalar curvatures. We present various solutions on various holomorphic line bundles over projectivespaces and their disc bundles, and discuss the phase change phenomenon when one suitably changes initialvalues.展开更多
It is well known that tip leakage flow has a strong effect on the compressor performance and stability. This paper reports on a numerical investigation of detailed flow structures in an isolated transonic compressor r...It is well known that tip leakage flow has a strong effect on the compressor performance and stability. This paper reports on a numerical investigation of detailed flow structures in an isolated transonic compressor rotor-NASA Rotor 37 at near stall and stalled conditions aimed at improving understanding of changes in 3D tip leakage flow structures with rotating stall inception.Steady and unsteady 3D Navier-Stokes analyses were conducted to investigate flow structures in the same rotor.For steady analysis,the predicted results agree well with the experimental data for the estimation of compressor rotor global performance.For unsteady flow analysis, the unsteady flow nature caused by the breakdown of the tip leakage vortex in blade tip region in the transonic compressor rotor at near stall condition has been captured with a single blade passage.On the other hand, the time-accurate unsteady computations of multi-blade passage at near stall condition indicate that the unsteady breakdown of the tip leakage vortex triggered the short length-scale-spike type rotating stall inception at blade tip region.It was the forward spillage of the tip leakage flow at blade leading edge resulting in the spike stall inception. As the mass flow ratio is decreased,the rotating stall cell was further developed in the blade passage.展开更多
The influence of the linear birefringence on magneto-optical property measurement for optical fibers is investigated theoretically and experimentally. The evolution of polarization in fibers is simulated by the Jones ...The influence of the linear birefringence on magneto-optical property measurement for optical fibers is investigated theoretically and experimentally. The evolution of polarization in fibers is simulated by the Jones matrix. To verify this theoretical model, a magneto-optical system is built to measure the input azimuth, output azimuth and ellipticity. The Faraday rotation of spun fibers with different pitches is measured. The Verdet constant increases, while the linear birefringence decreases as the pitch becomes smaller. For spun fibers with 1 mm pitch, the Verdet constant can be enhanced by about 20.7% at 660 nm, compared with that of the unspun fiber. The results indicate that smaller linear birefringence can provide more accurate Faraday rotation measurement.展开更多
At the energy regimes close to Planck scales, the usual structure of Lorentz symmetry fails to address certain fundamental issues and eventually breaks down, thus paving the way for an alternative road map. It is thus...At the energy regimes close to Planck scales, the usual structure of Lorentz symmetry fails to address certain fundamental issues and eventually breaks down, thus paving the way for an alternative road map. It is thus argued that some subgroup of proper Lorentz group could stand consistent and might possibly help us to circumvent this problem.It is this subgroup that goes by the name of Very Special Relativity(VSR). Apart from violating rotational symmetry,VSR is believed to preserve the very tenets of special relativity. The gaugeon formalism due to type-I Yokoyama and type-II Izawa are found to be invariant under BRST symmetry. In this paper, we analyze the scope of this invariance in the scheme of VSR. Furthermore, we will obtain VSR modified Lagrangian density using path integral derivation. We will explore the consistency of VSR with regard to these theories.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos.10425101, 10631050)National Basic Research Program of China (973 Project) (Grant No. 2006cB805905)
文摘We study the ordinary differential equations related to rotationally symmetric pseudo-Khler metricsof constant scalar curvatures. We present various solutions on various holomorphic line bundles over projectivespaces and their disc bundles, and discuss the phase change phenomenon when one suitably changes initialvalues.
基金National Natural Science Foundation of China(Project No:50806073)
文摘It is well known that tip leakage flow has a strong effect on the compressor performance and stability. This paper reports on a numerical investigation of detailed flow structures in an isolated transonic compressor rotor-NASA Rotor 37 at near stall and stalled conditions aimed at improving understanding of changes in 3D tip leakage flow structures with rotating stall inception.Steady and unsteady 3D Navier-Stokes analyses were conducted to investigate flow structures in the same rotor.For steady analysis,the predicted results agree well with the experimental data for the estimation of compressor rotor global performance.For unsteady flow analysis, the unsteady flow nature caused by the breakdown of the tip leakage vortex in blade tip region in the transonic compressor rotor at near stall condition has been captured with a single blade passage.On the other hand, the time-accurate unsteady computations of multi-blade passage at near stall condition indicate that the unsteady breakdown of the tip leakage vortex triggered the short length-scale-spike type rotating stall inception at blade tip region.It was the forward spillage of the tip leakage flow at blade leading edge resulting in the spike stall inception. As the mass flow ratio is decreased,the rotating stall cell was further developed in the blade passage.
基金supported by the National Natural Science Foundation of China(Nos.61177088,61275051,61227012,61475096,61422507 and 61520106014)the Science and Technology Commission of Shanghai Municipality of China(Nos.14511105602,14DZ1201403 and 15220721500)
文摘The influence of the linear birefringence on magneto-optical property measurement for optical fibers is investigated theoretically and experimentally. The evolution of polarization in fibers is simulated by the Jones matrix. To verify this theoretical model, a magneto-optical system is built to measure the input azimuth, output azimuth and ellipticity. The Faraday rotation of spun fibers with different pitches is measured. The Verdet constant increases, while the linear birefringence decreases as the pitch becomes smaller. For spun fibers with 1 mm pitch, the Verdet constant can be enhanced by about 20.7% at 660 nm, compared with that of the unspun fiber. The results indicate that smaller linear birefringence can provide more accurate Faraday rotation measurement.
文摘At the energy regimes close to Planck scales, the usual structure of Lorentz symmetry fails to address certain fundamental issues and eventually breaks down, thus paving the way for an alternative road map. It is thus argued that some subgroup of proper Lorentz group could stand consistent and might possibly help us to circumvent this problem.It is this subgroup that goes by the name of Very Special Relativity(VSR). Apart from violating rotational symmetry,VSR is believed to preserve the very tenets of special relativity. The gaugeon formalism due to type-I Yokoyama and type-II Izawa are found to be invariant under BRST symmetry. In this paper, we analyze the scope of this invariance in the scheme of VSR. Furthermore, we will obtain VSR modified Lagrangian density using path integral derivation. We will explore the consistency of VSR with regard to these theories.
