<正> From the k symmetric action of IIB string in AdS_2×S~2 background given by Zhou,we derive theequations of motion.By using the twisted dual transformation which was introduced by Hou,we construct the fl...<正> From the k symmetric action of IIB string in AdS_2×S~2 background given by Zhou,we derive theequations of motion.By using the twisted dual transformation which was introduced by Hou,we construct the flatcurrents,conserving non-local charge with one free parameter,for the superstring in AdS_2×S_2.展开更多
A systematic rigorous analysis of both massless fermion fields in the mass spectra of superstring theory is carried out. Our interest is in dynamical aspects of these fields. An explicit novel expression for the propa...A systematic rigorous analysis of both massless fermion fields in the mass spectra of superstring theory is carried out. Our interest is in dynamical aspects of these fields. An explicit novel expression for the propagator of the massless Rarita-Schwinger field (the gravitino), in the mass spectrum involving massless fermions in superstring theory in 10 dimensions, is derived. The analysis is carried in the presence of a non-constrained external source so that the full expression of the propagator emerges. The number of associated degrees of freedom is also obtained. We work in a Coulomb-like gauge. The massless Dirac field (the dilatino), the other massless fermion field in the mass spectra of superstring theory in 10 dimensions, is first investigated to this end.展开更多
A patch antenna and our proposed metamaterial patch antenna are simulated and compared. A high gain patch antenna using a single layer metamaterial superstrate with a near to zero refractive index(n)is proposed.The si...A patch antenna and our proposed metamaterial patch antenna are simulated and compared. A high gain patch antenna using a single layer metamaterial superstrate with a near to zero refractive index(n)is proposed.The simulation results provide that the gain of the proposed antenna is increased by about 7dB. Consequently,the high gain antenna can be easily obtained by using our metamaterial superstrate.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 90403019
文摘<正> From the k symmetric action of IIB string in AdS_2×S~2 background given by Zhou,we derive theequations of motion.By using the twisted dual transformation which was introduced by Hou,we construct the flatcurrents,conserving non-local charge with one free parameter,for the superstring in AdS_2×S_2.
文摘A systematic rigorous analysis of both massless fermion fields in the mass spectra of superstring theory is carried out. Our interest is in dynamical aspects of these fields. An explicit novel expression for the propagator of the massless Rarita-Schwinger field (the gravitino), in the mass spectrum involving massless fermions in superstring theory in 10 dimensions, is derived. The analysis is carried in the presence of a non-constrained external source so that the full expression of the propagator emerges. The number of associated degrees of freedom is also obtained. We work in a Coulomb-like gauge. The massless Dirac field (the dilatino), the other massless fermion field in the mass spectra of superstring theory in 10 dimensions, is first investigated to this end.
基金The project supported by National Natural Science Foundation of China under Grant No. 90403019 Acknowledgments We would like to thank Prof. Kang-Jie Shi for many stimulating discussions. Xie is also grateful to Zhan-Yun Wang, Xiao-Lin Cai, Pei Song, and Jun Feng for their helpful discussions, and especially A-Ping Yang＇s encouragements.
基金supported by the IT R&D program of MKE/IITA.2009-F-033-02,Study of technologies for improving the RF spectrum characteristics by using the meta-electromagnetic structure.
文摘A patch antenna and our proposed metamaterial patch antenna are simulated and compared. A high gain patch antenna using a single layer metamaterial superstrate with a near to zero refractive index(n)is proposed.The simulation results provide that the gain of the proposed antenna is increased by about 7dB. Consequently,the high gain antenna can be easily obtained by using our metamaterial superstrate.
