42,566 research outputs found
What kinds of coordinate can keep the Hawking temperature invariant for the static spherically symmetric black hole?
By studying the Hawking radiation of the most general static spherically
symmetric black hole arising from scalar and Dirac particles tunnelling, we
find the Hawking temperature is invariant in the general coordinate
representation (\ref{arbitrary1}), which satisfies two conditions: a) its
radial coordinate transformation is regular at the event horizon; and b) there
is a time-like Killing vector.Comment: 10 page
Pharmacokinetics of recombinant human erythropoietin applied subcutaneously to children with chronic renal failure
The single-dose pharmacokinetics of recombinant human erythropoietin (rHuEPO) given SC was investigated in 20 patients aged 7-20 years at different stages of chronic renal failure. In a pilot study we confirmed the lower bioavailability of the drug in 2 children when given SC compared with the IV route (24% and 43%, respectively). Following administration of 4,000 units/m2, rHuEPO SC effective serum erythropoietin concentrations increased from a mean baseline level (+/- SD) of 23 +/- 13 units/l to a mean peak concentration of 265 +/- 123 units/l, which was reached after 14.3 +/- 9.4 h, followed by a slow decline until baseline values were attained at 72 h. Mean residence time was 30 +/- 9 h and mean elimination half-time 14.3 +/- 7 h. The single-dose kinetics of SC rHuEPO in children with different degrees of renal failure are comparable to those in adult patients. Possibly, the higher efficacy of SC rHuEPO in patients with renal anaemia compared with IV rHuEPO is related to its prolonged action
Quantum Criticality and Inhomogeneous Magnetic Order in Fe-doped alpha-YbAlB4
The intermediate-valent polymorphs - and -YbAlB exhibit
quantum criticality and other novel properties not usually associated with
intermediate valence. Iron doping induces quantum criticality in
-YbAlB and magnetic order in both compounds. We report results of
muon spin relaxation (SR) experiments in the intermediate-valent alloys
-YbAlFeB, and 0.25. For we find
no evidence for magnetic order down to 25 mK\@. The dynamic muon spin
relaxation rate exhibits a power-law temperature dependence
, , in the temperature range 100 mK--2
K, in disagreement with predictions by theories of antiferromagnetic (AFM) or
valence quantum critical behavior. For , where AFM order develops in
the temperature range 7.5--10 K, where we find coexistence of meso- or
macroscopically segregated paramagnetic and AFM phases, with considerable
disorder in the latter down to 2 K.Comment: 9 pages, 10 figures, to be published in Phys. Rev.
Predicting and understanding spatio-temporal dynamics of species recovery : implications for Asian crested ibis Nipponia nippon conservation in China
Acknowledgements This work was supported by the National Natural Science Foundation of China (No. 31372218) and cofunded by the China Scholarship Council (CSC) and the ITC Research Fund, Enschede, the Netherlands. We thank Shaanxi Hanzhong Crested Ibis National Nature Reserve for sharing the data of nest site locations. We are grateful to Brendan Wintle, Justin Travis and two anonymous reviewers for helpful comments on a previous version of the manuscript.Peer reviewedPublisher PD
Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopy
We have performed high-resolution angle-resolved photoemission spectroscopy
on the optimally-doped BaKFeAs compound and determined
the accurate momentum dependence of the superconducting (SC) gap in four
Fermi-surface sheets including a newly discovered outer electron pocket at the
M point. The SC gap on this pocket is nearly isotropic and its magnitude is
comparable ( 11 meV) to that of the inner electron and hole
pockets (12 meV), although it is substantially larger than that of the
outer hole pocket (6 meV). The Fermi-surface dependence of the SC gap
value is basically consistent with () = coscos
formula expected for the extended s-wave symmetry. The observed finite
deviation from the simple formula suggests the importance of multi-orbital
effects.Comment: 4 pages, 3 figures, 1 tabl
Magnetoresistance in the s-d Model with Arbitrary Impurity Spin
The magnetoresistance, the number of the localized electrons, and the s-wave
scattering phase shift at the Fermi level for the s-d model with arbitrary
impurity spin are obtained in the ground state. To obtain above results some
known exact results of the Bethe ansatz method are used. As the impurity spin S
= 1/2, our results coincide with those obtained by Ishii \textit{et al%}. The
compairsion between the theoretical and experimental magneticresistence for
impurity S = 1/2 is re-examined.Comment: 6 pages, 2 figure
Spectroscopy of triplet Rydberg states
A combined experimental and theoretical spectroscopic study of high-, , triplet and Rydberg states in
is presented. has a large nuclear spin,
, and at high- the hyperfine interaction becomes comparable to, or
even larger than, the fine structure and singlet-triplet splittings which poses
a considerable challenge both for precision spectroscopy and for theory. For
high- states, the hyperfine shifts are evaluated
non-perturbatively taking advantage of earlier spectroscopic data for the
isotope , which results in good agreement with the
present measurements. For the states, this procedure is reversed by
first extracting from the present measurements the energies of
the states to be expected for isotopes without hyperfine
structure () which allows the determination of corrected
quantum defects in the high- limit.Comment: 13 pages, 8 figure
Nonlinear phenomena of the buck-boost converter analyzed by storage energy
Author name used in this publication: K. W. E. ChengAuthor name used in this publication: Z. H. ShiAuthor name used in this publication: K. DingVersion of RecordPublishe
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