Horizontal winds in the mesosphere （80-100 km） were measured by meteor radar in Wuhan, China （30° N, 114° E） over a 45-month interval in 2002-2005 and the data examined to investigate the monthly mean be...Horizontal winds in the mesosphere （80-100 km） were measured by meteor radar in Wuhan, China （30° N, 114° E） over a 45-month interval in 2002-2005 and the data examined to investigate the monthly mean behavior of the Ol tide. A clear seasonal variation in amplitude of the O1 tide ranging from -0.3 m/s to 2.6 m/s was observed. In most months, the northward and eastward components differed by about 7 lunar hours with the eastward component leading. Comparison of the amplitudes of the M2 and O1 tides suggests the O1 tide is quite stronger over Wuhan, China. The amplitude ratio of the O1 tide to the M2 tide is quite stronger than that the gravitational potential being 0.41. The vertical wavelength of the O1 tide differs on a monthly basis. Height profiles of the O1 tide showed obvious height variation. The O1 tide is stronger in January and July. In different month, the vertical wavelength for the O1 tide changes considerably at the same height. The year＇s variation trend of the northward and eastward components is very similar in both phase and amplitude.展开更多
A Fourier transform （FT） spectrum of praseodymium （Pr） extending from UV to IR was investigated. Hyperfine （hf） structures of unclassified lines with sufficiently high signal to noise ratio （SNR） were analyzed...A Fourier transform （FT） spectrum of praseodymium （Pr） extending from UV to IR was investigated. Hyperfine （hf） structures of unclassified lines with sufficiently high signal to noise ratio （SNR） were analyzed and some new levels were found. We present these new levels in this work. Some of the new levels have energies almost equal to the energies of already known or other new levels, distinguished either by different values of angular momentum J or by their parity.展开更多
Over the past two decades, scientific drilling into sediments and rocks in the ocean and the continent has revealed the presence of physiologically and phylogenetically complex microbial life in the deep subsurface. M...Over the past two decades, scientific drilling into sediments and rocks in the ocean and the continent has revealed the presence of physiologically and phylogenetically complex microbial life in the deep subsurface. Microorganisms, most of which have no cultured or known relatives in the surface biosphere, have been discovered in sediments and rock at depth as deep as 1 km below the seafloor and more than 3 km deep in the continent. The deep biosphere probably represents the most voluminous part of the global biosphere and may constitute as much as 50% of the Earth’s biomass. In this article, we review the current knowledge of and most recent advances in studying the deep biosphere and suggest directions in future research.展开更多
基金Acknowledgements This research was supported by National Natural Science Foundation of China （41104095）
文摘Horizontal winds in the mesosphere （80-100 km） were measured by meteor radar in Wuhan, China （30° N, 114° E） over a 45-month interval in 2002-2005 and the data examined to investigate the monthly mean behavior of the Ol tide. A clear seasonal variation in amplitude of the O1 tide ranging from -0.3 m/s to 2.6 m/s was observed. In most months, the northward and eastward components differed by about 7 lunar hours with the eastward component leading. Comparison of the amplitudes of the M2 and O1 tides suggests the O1 tide is quite stronger over Wuhan, China. The amplitude ratio of the O1 tide to the M2 tide is quite stronger than that the gravitational potential being 0.41. The vertical wavelength of the O1 tide differs on a monthly basis. Height profiles of the O1 tide showed obvious height variation. The O1 tide is stronger in January and July. In different month, the vertical wavelength for the O1 tide changes considerably at the same height. The year＇s variation trend of the northward and eastward components is very similar in both phase and amplitude.
文摘A Fourier transform （FT） spectrum of praseodymium （Pr） extending from UV to IR was investigated. Hyperfine （hf） structures of unclassified lines with sufficiently high signal to noise ratio （SNR） were analyzed and some new levels were found. We present these new levels in this work. Some of the new levels have energies almost equal to the energies of already known or other new levels, distinguished either by different values of angular momentum J or by their parity.
文摘Over the past two decades, scientific drilling into sediments and rocks in the ocean and the continent has revealed the presence of physiologically and phylogenetically complex microbial life in the deep subsurface. Microorganisms, most of which have no cultured or known relatives in the surface biosphere, have been discovered in sediments and rock at depth as deep as 1 km below the seafloor and more than 3 km deep in the continent. The deep biosphere probably represents the most voluminous part of the global biosphere and may constitute as much as 50% of the Earth’s biomass. In this article, we review the current knowledge of and most recent advances in studying the deep biosphere and suggest directions in future research.
