1,920 research outputs found
Extremely large perpendicular magnetic anisotropy of an Fe(001) surface capped by 5d transition metal monolayers: A density functional study
Significant enhancement of the magnetocrystalline anisotropy (MCA) of an Fe(001) surface capped by 4d and 5d transition metal monolayers is presented in this study using first principles density functional calculations. In particular, an extremely large perpendicular MCA of +10 meV/Ir was found in Ir-capped Fe(001), which originates not from the Fe but from the large spin-orbit coupling of the Ir atoms. From the spin-channel decomposition of the MCA matrix and electronic structure analyses, we find that strong 3d-5d band hybridization in the minority spin state is responsible for the sign changes of the MCA from parallel to perpendicular.open0
Design and fabrication of double pancake coil using 2G wire for conduction cooled superconducting magnet
AbstractA large bore double pancake coil(DPC) was designed and tested with 2G HTS wire to develop the conduction cooled superconducting magnet with central field intensity of 3 T at 20K operating temperature and clear bore of 100mm at room temperature. The effect of insulation between turns of double pancake coils was tested. Two double pancake coils with and without turn to turn insulation were wound using 4mm wide 2G conductor. A temporary result suggests that the coil wound without electrical insulation can be protected from higher over current and shows improved stability
Morphing Planar Graph Drawings Optimally
We provide an algorithm for computing a planar morph between any two planar
straight-line drawings of any -vertex plane graph in morphing steps,
thus improving upon the previously best known upper bound. Further, we
prove that our algorithm is optimal, that is, we show that there exist two
planar straight-line drawings and of an -vertex plane
graph such that any planar morph between and requires
morphing steps
A characteristic free criterion of birationality
One develops {\em ab initio} the theory of rational/birational maps over
reduced, but not necessarily irreducible, projective varieties in arbitrary
characteristic. A numerical invariant of a rational map is introduced, called
the Jacobian dual rank. It is proved that a rational map in this general setup
is birational if and only if the Jacobian dual rank attains its maximal
possible value. Even in the "classical" case where the source variety is
irreducible there is some gain for this invariant over the degree of the map as
it is, on one hand, intrinsically related to natural constructions in
commutative algebra and, on the other hand, is effectively straightforwardly
computable. Applications are given to results so far only known in
characteristic zero. In particular, the surprising result of Dolgachev
concerning the degree of a plane polar Cremona map is given an alternative
conceptual angle.Comment: 24 page
Community analysis of aggregated bacteria in southern Lake Baikal
The main aim of this study is to unveiling the community structure of aggregated bacteria in lake Baikal and determining the relations with free-living bacteria. For achieving this aim, FISH method was applied to free-living and aggregated bacteria in Lake Baikal at April, 2001. Bacterial counts of free-living bacteria by DAPI staining ranged from 0.2×10⁶ to 3.2×10⁶ cells·ml⁻¹, which decreased with depths, whereas aggregated bacterial numbers dramatically increased with depths, ranged from 0.4×10⁴ to 3.3×10⁴ cells·ml⁻¹. Also, the ratios of EUB probe binding cells to DAPI counts ranged from 52.3 to 74.1% in free-living bacteria, from 39.6 to 66.7% in aggregated bacteria, respectively. Community composition of aggregated bacteria was very different from free-livng bacteria. Especially, that is remarked at 25m depth which is observed the highest value phytoplankton. The vertical profile of aggregated bacteria community was very particular. β-Proteobacteria was increasing with depth till 100m. In 250m depth, γ-Proteobacteria was 44% of DAPI bound cells, while other groups were less than 1%. In conclusion, the bacterial community structures of free-living and aggregated bacteria were very different, and they sustain the independent ecosystem separately.Article信州大学山地水環境教育研究センター研究報告 2: 91-95(2004)departmental bulletin pape
Anthropogenic point-source and non-point-source nitrogen inputs into Huai River basin and their impacts on riverine ammonia–nitrogen flux
This study provides a new approach to estimate both anthropogenic non-point-source and point-source nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River basin of China, a water–shed with one of the highest levels of N input in the world. Multi-year average (2003-2010) inputs of N to the watershed are 27 200 ± 1100 kg N km-2 yr-1. Non-point sources comprised about 98 % of total N input, and only 2 % of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River basin (69 % of net anthropogenic N inputs), followed by atmospheric deposition (20 %), N fixation in croplands (7 %), and N content of imported food and feed (2 %). High N inputs showed impacts on riverine AN flux: fertilizer application, point-source N input, and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams may influence the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from both point sources and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.This study was financially supported by the Key Research Program of the Chinese Academy of Sciences (no. KZZD-EW-10-02-3), the 13th Five-Year Plan of Chinese Academy of Sciences (no. YSW2013B02) and State Key Laboratory of Urban and Regional Ecology scientific project (no. SKLURE2013-1-05). The authors wish to express their gratitude to the China Scholarship Council (201408110138) for funding the visiting venture that generated this paper, and to Huai River Basin Water Resources Protection Bureau and Hydrologic Information Center of Huai River Commission for providing water quality and hydrological data
Reverse-link performance of synchronous DS-CDMA systems in dispersive Rician multipath fading channels
Synchronization in a System of Globally Coupled Oscillators with Time Delay
We study the synchronization phenomena in a system of globally coupled
oscillators with time delay in the coupling. The self-consistency equations for
the order parameter are derived, which depend explicitly on the amount of
delay. Analysis of these equations reveals that the system in general exhibits
discontinuous transitions in addition to the usual continuous transition,
between the incoherent state and a multitude of coherent states with different
synchronization frequencies. In particular, the phase diagram is obtained on
the plane of the coupling strength and the delay time, and ubiquity of
multistability as well as suppression of the synchronization frequency is
manifested. Numerical simulations are also performed to give consistent
results
Interface Motion and Pinning in Small World Networks
We show that the nonequilibrium dynamics of systems with many interacting
elements located on a small-world network can be much slower than on regular
networks. As an example, we study the phase ordering dynamics of the Ising
model on a Watts-Strogatz network, after a quench in the ferromagnetic phase at
zero temperature. In one and two dimensions, small-world features produce
dynamically frozen configurations, disordered at large length scales, analogous
of random field models. This picture differs from the common knowledge
(supported by equilibrium results) that ferromagnetic short-cuts connections
favor order and uniformity. We briefly discuss some implications of these
results regarding the dynamics of social changes.Comment: 4 pages, 5 figures with minor corrections. To appear in Phys. Rev.
Planar Octilinear Drawings with One Bend Per Edge
In octilinear drawings of planar graphs, every edge is drawn as an
alternating sequence of horizontal, vertical and diagonal ()
line-segments. In this paper, we study octilinear drawings of low edge
complexity, i.e., with few bends per edge. A -planar graph is a planar graph
in which each vertex has degree less or equal to . In particular, we prove
that every 4-planar graph admits a planar octilinear drawing with at most one
bend per edge on an integer grid of size . For 5-planar
graphs, we prove that one bend per edge still suffices in order to construct
planar octilinear drawings, but in super-polynomial area. However, for 6-planar
graphs we give a class of graphs whose planar octilinear drawings require at
least two bends per edge
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