We study the interaction of a weak probe field, having two circular polarized components, i.e., cr- and a＋ polarization, with an optically dense medium of four-level atoms in a double-A configuration, which is mediat...We study the interaction of a weak probe field, having two circular polarized components, i.e., cr- and a＋ polarization, with an optically dense medium of four-level atoms in a double-A configuration, which is mediated by the electromagnetically induced transparency with a polarized control light with spatially inhomogeneous profile. We analyse the deflection of the polarized probe light and we find that we can selectively determine which circular component will be deflected after the polarized probe light enters the atom medium via adjusting the polarization and detuning of the control field.展开更多
On top of Shigujian Peak(1477 m a.s.l.) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to around one meter and d...On top of Shigujian Peak(1477 m a.s.l.) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to around one meter and depth from 10 cm to 45 cm are found on rock surface.These pits mainly appear on the NE and SE sides, and their drainage mouths are in the same direction.The identification results through micropolariscope and X-ray fluorescence spectrometer reveal that bedrock of pits is from middle to fine-grained moyite being apt to be weathered and modified.In Dayangshan region the annual mean temperature is 9.2℃ and annual precipitation is over 1700 mm.On the one hand, there always experiences a period of periglacial action with temperature oscillating near 0℃ for 4 months, i.e., from December to March next year.As a consequence, the freezing-thawing cycles may be remarkable to disintegrate the bedrock.On the other hand, the windward slope of Shigujian Peak meets typhoon of over force 10 on the Beaufort scale in summer, therefore, the blowing makes suspending sands or pebbles grind in swirling form.Based on field investigation and periglacial geomorphic theory, the pits on top of Shigujian Peak are attributed to freez-ing-thawing of periglacial action.Meanwhile, storm and strong wind accelerate the process.Observation shows that both the actions are still undergoing and variant directions of wind are the main cause for making different shapes of the pits.Because the top of Shigujian is 1500 m lower than the present snow line, some scholars considered that"glacial pothole"formed in the Quaternary is hard to work, even though in the Last Glacial Maximum(LGM).展开更多
基金Supported by the National Fundamental Research Program under Grant No. 2007CB925204the National Natural Science Foundation under Grant Nos. 10947135 and 10775048+4 种基金the Opening Project of Key Laboratory of Low Dimensional Quantum Structures and Quantum Control (Hunan Normal University),Ministry of Education, under Grant No. QSQC0903the Scientific Research Fund of Hunan Provincial Education Department under Grant No. 09C062the Construct Program of the Key Discipline in Hunan Provincethe Construct Program of the Key discipline in Changsha University of Science and Technologythe Foundation of Changsha University of Science and Technology
文摘We study the interaction of a weak probe field, having two circular polarized components, i.e., cr- and a＋ polarization, with an optically dense medium of four-level atoms in a double-A configuration, which is mediated by the electromagnetically induced transparency with a polarized control light with spatially inhomogeneous profile. We analyse the deflection of the polarized probe light and we find that we can selectively determine which circular component will be deflected after the polarized probe light enters the atom medium via adjusting the polarization and detuning of the control field.
基金Regional landform and landscape survey programme of the Zhejiang Institute of Geological Survey
文摘On top of Shigujian Peak(1477 m a.s.l.) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to around one meter and depth from 10 cm to 45 cm are found on rock surface.These pits mainly appear on the NE and SE sides, and their drainage mouths are in the same direction.The identification results through micropolariscope and X-ray fluorescence spectrometer reveal that bedrock of pits is from middle to fine-grained moyite being apt to be weathered and modified.In Dayangshan region the annual mean temperature is 9.2℃ and annual precipitation is over 1700 mm.On the one hand, there always experiences a period of periglacial action with temperature oscillating near 0℃ for 4 months, i.e., from December to March next year.As a consequence, the freezing-thawing cycles may be remarkable to disintegrate the bedrock.On the other hand, the windward slope of Shigujian Peak meets typhoon of over force 10 on the Beaufort scale in summer, therefore, the blowing makes suspending sands or pebbles grind in swirling form.Based on field investigation and periglacial geomorphic theory, the pits on top of Shigujian Peak are attributed to freez-ing-thawing of periglacial action.Meanwhile, storm and strong wind accelerate the process.Observation shows that both the actions are still undergoing and variant directions of wind are the main cause for making different shapes of the pits.Because the top of Shigujian is 1500 m lower than the present snow line, some scholars considered that"glacial pothole"formed in the Quaternary is hard to work, even though in the Last Glacial Maximum(LGM).
