@article{7308,
abstract = {Carbon has been used widely as the basis of porous cathodes for nonaqueous Li–O2 cells. However, the stability of carbon and the effect of carbon on electrolyte decomposition in such cells are complex and depend on the hydrophobicity/hydrophilicity of the carbon surface. Analyzing carbon cathodes, cycled in Li–O2 cells between 2 and 4 V, using acid treatment and Fenton’s reagent, and combined with differential electrochemical mass spectrometry and FTIR, demonstrates the following: Carbon is relatively stable below 3.5 V (vs Li/Li+) on discharge or charge, especially so for hydrophobic carbon, but is unstable on charging above 3.5 V (in the presence of Li2O2), oxidatively decomposing to form Li2CO3. Direct chemical reaction with Li2O2 accounts for only a small proportion of the total carbon decomposition on cycling. Carbon promotes electrolyte decomposition during discharge and charge in a Li–O2 cell, giving rise to Li2CO3 and Li carboxylates (DMSO and tetraglyme electrolytes). The Li2CO3 and Li carboxylates present at the end of discharge and those that form on charge result in polarization on the subsequent charge. Li2CO3 (derived from carbon and from the electrolyte) as well as the Li carboxylates (derived from the electrolyte) decompose and form on charging. Oxidation of Li2CO3 on charging to ∼4 V is incomplete; Li2CO3 accumulates on cycling resulting in electrode passivation and capacity fading. Hydrophilic carbon is less stable and more catalytically active toward electrolyte decomposition than carbon with a hydrophobic surface. If the Li–O2 cell could be charged at or below 3.5 V, then carbon may be relatively stable, however, its ability to promote electrolyte decomposition, presenting problems for its use in a practical Li–O2 battery. The results emphasize that stable cycling of Li2O2 at the cathode in a Li–O2 cell depends on the synergy between electrolyte and electrode; the stability of the electrode and the electrolyte cannot be considered in isolation.},
author = {Ottakam Thotiyl, Muhammed M. and Freunberger, Stefan Alexander and Peng, Zhangquan and Bruce, Peter G.},
issn = {0002-7863},
journal = {Journal of the American Chemical Society},
number = {1},
pages = {494--500},
publisher = {ACS},
title = {{The carbon electrode in nonaqueous Li–O2 cells}},
doi = {10.1021/ja310258x},
volume = {135},
year = {2012},
}
@article{6588,
abstract = {First we note that the best polynomial approximation to vertical bar x vertical bar on the set, which consists of an interval on the positive half-axis and a point on the negative half-axis, can be given by means of the classical Chebyshev polynomials. Then we explore the cases when a solution of the related problem on two intervals can be given in elementary functions.},
author = {Pausinger, Florian},
issn = {1812-9471},
journal = {Journal of Mathematical Physics, Analysis, Geometry},
number = {1},
pages = {63--78},
publisher = {B. Verkin Institute for Low Temperature Physics and Engineering},
title = {{Elementary solutions of the Bernstein problem on two intervals}},
volume = {8},
year = {2012},
}
@article{7776,
abstract = {We present an analysis of finite-size effects in jammed packings of N soft, frictionless spheres at zero temperature. There is a 1/N correction to the discrete jump in the contact number at the transition so that jammed packings exist only above isostaticity. As a result, the canonical power-law scalings of the contact number and elastic moduli break down at low pressure. These quantities exhibit scaling collapse with a nontrivial scaling function, demonstrating that the jamming transition can be considered a phase transition. Scaling is achieved as a function of N in both two and three dimensions, indicating an upper critical dimension of 2.},
author = {Goodrich, Carl Peter and Liu, Andrea J. and Nagel, Sidney R.},
issn = {0031-9007},
journal = {Physical Review Letters},
number = {9},
publisher = {American Physical Society},
title = {{Finite-size scaling at the jamming transition}},
doi = {10.1103/physrevlett.109.095704},
volume = {109},
year = {2012},
}
@article{2904,
abstract = {Generalized van der Corput sequences are onedimensional, infinite sequences in the unit interval. They are generated from permutations in integer base b and are the building blocks of the multi-dimensional Halton sequences. Motivated by recent progress of Atanassov on the uniform distribution behavior of Halton sequences, we study, among others, permutations of the form P(i) = ai (mod b) for coprime integers a and b. We show that multipliers a that either divide b - 1 or b + 1 generate van der Corput sequences with weak distribution properties. We give explicit lower bounds for the asymptotic distribution behavior of these sequences and relate them to sequences generated from the identity permutation in smaller bases, which are, due to Faure, the weakest distributed generalized van der Corput sequences.},
author = {Pausinger, Florian},
issn = {2118-8572},
journal = {Journal de Theorie des Nombres des Bordeaux},
number = {3},
pages = {729 -- 749},
publisher = {Universite de Bordeaux},
title = {{Weak multipliers for generalized van der Corput sequences}},
doi = {10.5802/jtnb.819},
volume = {24},
year = {2012},
}
@unpublished{2928,
abstract = { This paper addresses the problem of approximate MAP-MRF inference in general graphical models. Following [36], we consider a family of linear programming relaxations of the problem where each relaxation is specified by a set of nested pairs of factors for which the marginalization constraint needs to be enforced. We develop a generalization of the TRW-S algorithm [9] for this problem, where we use a decomposition into junction chains, monotonic w.r.t. some ordering on the nodes. This generalizes the monotonic chains in [9] in a natural way. We also show how to deal with nested factors in an efficient way. Experiments show an improvement over min-sum diffusion, MPLP and subgradient ascent algorithms on a number of computer vision and natural language processing problems. },
author = {Kolmogorov, Vladimir and Schoenemann, Thomas},
booktitle = {arXiv},
pages = {16},
publisher = {ArXiv},
title = {{Generalized sequential tree-reweighted message passing}},
year = {2012},
}