17,925 research outputs found
Western colonial representations of the other: the case of Exotica Tibet
Alexandra David-Néel had influenced many belletrists as well as academics interested in Tibet by her travelogues and notes from journeys to Tibet, China, Nepal, Mongolia, and India. This text focuses on the image of her personality outlined in one of her most famous books, Voyage d'une Parisienne a Lhassa à Pied et en Mendiant de la Chine à l'Inde à Travers le Thibet, 1927. The image of a woman travelling to the forbidden mystical country, early anthropologist fascinated by Tibetan customs, and capable writer of novels pervades her books and gives an understanding of perspective oriental studies and early beginnings of Tibetan studies in Europe
Metallic behavior induced by potassium doping of the trigonal antiferromagnetic insulator EuMn2As2
We report magnetic susceptibility \chi, isothermal magnetization M, heat
capacity C_p and electrical resistivity \rho measurements on undoped EuMn2As2
and K-doped Eu0.96K0.04Mn2As2 and Eu0.93K0.07Mn2As2 single crystals with the
trigonal CaAl2Si2-type structure as a function of temperature T and magnetic
field H. EuMn2As2 has an insulating ground state with an activation energy of
52 meV and exhibits antiferromagnetic (AFM) ordering of the Eu+2 spins S=7/2 at
T_N1 = 15 K from C_p(T) and \chi(T) data with a likely spin-reorientation
transition at T_N2 = 5.0 K. The Mn+2 3d5 spins-5/2 exhibit AFM ordering at T_N
= 142 K from all three types of measurements. The M(H) isotherm and \chi(T)
data indicate that the Eu AFM structure is both noncollinear and noncoplanar.
The AFM structure of the Mn spins is also unclear. A 4% substitution of K for
Eu in Eu0.96K0.04Mn2As2 is sufficient to induce a metallic ground state.
Evidence is found for a difference in the AFM structure of the Eu moments in
the metallic crystals from that of undoped EuMn2As2 versus both T and H. For
metallic Eu0.96K0.04Mn2As2 and Eu0.93K0.07Mn2As2, an anomalous S-shape T
dependence of \rho related to the Mn magnetism is found. Upon cooling from 200
K, \rho exhibits a strong negative curvature, reaches maximum positive slope at
the Mn T_N ~ 150 K, and then continues to decrease but more slowly below T_N.
This suggests that dynamic short-range AFM order of the Mn spins above the Mn
T_N strongly suppresses the resistivity, contrary to the conventional decrease
of \rho that is only observed upon cooling below T_N of an antiferromagnet.Comment: 21 pages, 22 figures, 4 Table
Roll Resonance for a Gravity-gradient Satellite
Roll and attitude stability for gravity gradient satellite
Cosmic Origins Spectrograph Observations of Warm Intervening Gas Towards 3C263
We present HST/COS high S/N observations of the z = 0.32566 multi-phase
absorber towards 3C263. The COS data shows absorption from H I, O VI, C III, N
III, Si III and C II. The Ne VIII in this absorber is detected in the FUSE
spectrum. The low and intermediate ions are kinematically aligned with each
other and H I and display narrow line widths of 6 km/s. The O VI lines are
kinematically offset by 12 km/s from the low ions and are a factor of four
broader. All metal ions except O VI and Ne VIII are consistent with an origin
in gas photoionized by the extragalactic background radiation. The bulk of the
observed H I is also traced by this photoionized medium. The carbon abundance
in this gas phase is near-solar. The O VI and Ne VIII favor an origin in
collisionally ionized gas at T = 5.2 x 10^5 K. The H I absorption associated
with this warm absorber is a BLA marginally detected in the COS spectrum. This
warm gas phase has total hydrogen column density of N(H) ~ 3 x 10^19 which is 2
dex higher than what is traced by the photoionized gas. Simultaneous detection
of O VI, Ne VIII and BLAs in an absorber can be a strong diagnostic of gas with
temperature in the range of 10^5 - 10^6 K corresponding to the warm phase of
the WHIM or shock-heated gas in the extended halos of galaxies.Comment: Accepted for publication in the Astrophysical Journa
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