Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a ce...
Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19% of this excess in the abyssal ocean beneath 2,000 m, dominated by Southern Ocean warming. The ocean also has taken up about 27% of anthropogenic carbon, resulting in acidification of the upper ocean. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcingand ventilation. The most recent decade of global hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (∼20%) and deep-ocean oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the ocean's overturning circulation.
We present a study of the precessional dynamics of exchange coupled Ni 81Fe19/Ni81Fe19:Eux, bilayers, 50 nm thick. Eu codopants are of interest in soft ferromagnetic films since they can be used to enhance the gigaher...
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We present a study of the precessional dynamics of exchange coupled Ni 81Fe19/Ni81Fe19:Eux, bilayers, 50 nm thick. Eu codopants are of interest in soft ferromagnetic films since they can be used to enhance the gigahertz precessional frequency (f p) in Ni81Fe19 thin films without contributing to damping. Under-damped precessional dynamics with fp 'tunable' by as much as roughly 0.3 GHz were observed. Dynamical behavior agrees well with a single-domain Landau-Lifshitz simulation at constant relaxation rate λ/4π = 150 MHz across the series. The variation of precessional frequency with bias field shows that the enhancement of resonant frequency arises from an increase of dynamic anisotropy HK, matched well by static HK as measured by SQUID. An increasing contribution in g factor (2.1-2.4) is mostly balanced by a decreasing saturation magnetization Ms.
作者：
HARRISON, CHARLES W.COMMANDER CHARLES W. HARRISON
JR. USN attended the U. S. Naval Academy Preparatory School the U. S. Coast Guard Academy and the University of Virginia where in 1939 he received the S.B. degree in Engineering and in 1940 the degree of Electrical Engineer. In 1942 he was graduated with the S.M. degree in Communication Engineering from Cruft Laboratory Harvard University and that summer completed the Navy Course in Radar Engineering at Massachusetts Institute of Technology. Subsequently for several years he was engaged in lecturing to officers of the Armed Forces assigned to the radar schools at Harvard and Princeton Universities. He has had four tours of duty in the Electronics Design and Development Division Bureau of Ships two at the U.S. Naval Research Laboratoryone at the Signal Corps Engineering Laboratories (Evans Signal Laboratory)and one at the Philadelphia Naval Shipyard. His experience includes amateur
naval and broadcasting operation. In 1951 Commander Harrison was selected for training in Advanced Science at Harvard University under sponsorship of the Office of Naval Research. This program led to the M. Eng. degree in 1952 and Ph.D. degree in Applied Physics in 1954. Commander Harrison is presently Electronics Officer on the Staff of Commander Operational Development Force. He is a member of several societies and associations including the Harvard Chapter of the Society of Sigma Xi.
Summary: The measurement of the magnetic field associated with a linearly or elliptically polarized electric field, using a small loop, or magnetic probe, is discussed. It is shown that in general a loop will not meas...
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