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1.
2.
Effect of nickel coating on electrochemical performance of graphite anodes for lithium ion batteries
Among the different materials often studied and proposed as negative electrodes for lithium-ion batteries, graphite anodes
are the most used in commercial batteries. For this study, synthetic graphite was tested. During the first discharge 0.2 Li
ions were consumed for the formation of the SEI film and the capacity reaches about 387 mAh/g. But at the end of the first
charge only 72% of the initial charge was recovered (the reversible capacity is about 279 mAh/g). In order to improve this
performance we have deposited metallic nickel on graphite with the intention to obtain a homogeneous thin layer able to modify
the nature of the SEI film, to allow the diffusion of lithium ions through the protective layer, and also to increase the
performance of graphite electrodes. The results show a decrease of the irreversible capacity loss (16% instead of 28% for
pure graphite electrodes) as well as better cycleability for a nickel-deposited graphite electrode with only 11% weight ratio
of nickel. On the other hand, an increase of the nickel content decreases this performance. 相似文献
3.
Usually, numerical self-consistent calculations predict a much larger intrinsic bistability region than actually is measured in resonant tunneling diodes (RTDs). In addition, numerical calculations have shown that scattering in the well reduces bistability. We used a unified treatment of current flowing from continuum states and emitter quasi-bound states to show numerically and analytically that not only the scattering in the quantum well but also the scattering in the emitter reduces bistability. Moreover, within the Hartree approximation, bistability occurs by tunneling resonantly between emitter quasi-bound state and well quasi-bound state as a pitchfork bifurcation. 相似文献
4.
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6.
E. E. Grinberg Yu. I. Levin V. Z. Krasil’shchik I. E. Strel’nikova A. I. Vargunin R. A. Sandu E. A. Ryabenko I. B. Golubeva 《Russian Journal of Applied Chemistry》2012,85(3):391-395
Purification of a number of silicon derivatives (chloride, lower alcoholates) formed in processing of high-purity silicon for electronic and electrical industries was considered. It was found that high-purity substances suitable for use in electronics and optics can be produced from industrial wastes. 相似文献
7.
Popescu S 《Physical review letters》2007,99(13):130503
A Knill-Laflamme-Milburn (KLM) type quantum computation with bosonic neutral atoms or bosonic ions is suggested. Crucially, as opposite to other quantum computation schemes involving atoms (ions), no controlled interactions between atoms (ions) involving their internal levels are required. Versus photonic KLM computation, this scheme has the advantage that single-atom (ion) sources are more natural than single-photon sources, and single-atom (ion) detectors are far more efficient than single-photon ones. 相似文献
8.
We address the problem of "nonlocal computation," in which separated parties must compute a function without any individual learning anything about the inputs. Surprisingly, entanglement provides no benefit over local classical strategies for such tasks, yet stronger nonlocal correlations allow perfect success. This provides intriguing insights into the limits of quantum information processing, the nature of quantum nonlocality, and the differences between quantum and stronger-than-quantum nonlocal correlations. 相似文献
9.
It is proved that the following conditions are equivalent for an arbitrary commutative Moufang loop
:1) the loop
is finite over the center;2) every subloop of
defines a finite conjugacy class of subloops;3) every associative subloop of
defines a finite conjugacy class of subloops;4) every infinite associative subloop of
defines a finite conjugacy class of subloops. 相似文献
10.
Reproducing kernel spaces introduced by L. de Branges and J. Rovnyak provide isometric, coisometric and unitary realizations for Schur functions, i.e. for matrix-valued functions analytic and contractive in the open unit disk. In our previous paper [12] we showed that similar realizations exist in the nonstationary setting, i.e. when one considers upper triangular contractions (which appear in time-variant system theory as transfer functions of dissipative systems) rather than Schur functions and diagonal operators rather than complex numbers. We considered in [12] realizations centered at the origin. In the present paper we study realizations of a more general kind, centered at an arbitrary diagonal operator. Analogous realizations (centered at a point of the open unit disk) for Schur functions were introduced and studied in [3] and [4]. 相似文献