1,185 research outputs found
On the spectrum of the AdS(5) x S-5 string at large lambda
archiveprefix: arXiv primaryclass: hep-th reportnumber: HU-EP-10-85 slaccitation: %%CITATION = ARXIV:1012.4471;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: HU-EP-10-85 slaccitation: %%CITATION = ARXIV:1012.4471;%
A note on the integral equation for the Wilson loop in N = 2 D=4 superconformal Yang-Mills theory
We propose an alternative method to study the saddle point equation in the
strong coupling limit for the Wilson loop in D=4 super
Yang-Mills with an SU(N) gauge group and 2N hypermultiplets. This method is
based on an approximation of the integral equation kernel which allows to solve
the simplified problem exactly. To determine the accuracy of this
approximation, we compare our results to those obtained recently by Passerini
and Zarembo. Although less precise, this simpler approach provides an explicit
expression for the density of eigenvalues that is used to derive the planar
free energy.Comment: 12 pages, v2: section 2.5 (Free Energy) amended and reference added,
to appear in J. Phys.
Scalable Synthesis of Microsized, Nanocrystalline ZnFeO-C Secondary Particles and Their Use in ZnFe O-C/LiNiMnO Lithium-Ion Full Cells
Conversion/alloying materials (CAMs) are a potential alternative to graphite as Liâion anodes, especially for highâpower performance. The so far most investigated CAM is carbonâcoated ZnFeO, which provides very high specific capacity of more than 900 mAhâg and good rate capability. Especially for the latter the optimal particle size is in the nanometer regime. However, this leads to limited electrode packing densities and safety issues in largeâscale handling and processing. Herein, a new synthesis route including three sprayâdrying steps that results in the formation of microsized, spherical secondary particles is reported. The resulting particles with sizes of 10â15 Îźm are composed of carbonâcoated ZnFeO nanocrystals with an average diameter of approximately 30â40 nm. The carbon coating ensures fast electron transport in the secondary particles and, thus, high rate capability of the resulting electrodes. Coupling partially prelithiated, carbonâcoated ZnFeO anodes with LiNiMnO cathodes results in cobaltâfree Liâion cells delivering a specific energy of up to 284 Whâkg (at 1âC rate) and power of 1105 Wâkgâ1 (at 3âC) with remarkable energy efficiency (>93â% at 1âC and 91.8â% at 3âC)
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