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991.
In view of the continuously worsening environmental problems, fossil fuels will not be able to support the development of human life in the future. Hence, it is of great importance to work on the efficient utilization of cleaner energy resources. In this case, cheap, reliable, and eco-friendly grid-scale energy storage systems can play a key role in optimizing our energy usage. When compared with lithium-ion and lead-acid batteries, the excellent safety, environmental benignity, and low toxicity of aqueous Zn-based batteries make them competitive in the context of large-scale energy storage. Among the various Zn-based batteries, due to a high open-circuit voltage and excellent rate performance, Zn-Ni batteries have great potential in practical applications. Nevertheless, the intrinsic obstacles associated with the use of Zn anodes in alkaline electrolytes, such as dendrite, shape change, passivation, and corrosion, limit their commercial application. Hence, we have focused our current efforts on inhibiting the corrosion and dissolution of Zn species. Based on a previous study from our research group, the failure of the Zn-Ni battery was caused by the shape change of the Zn anode, which stemmed from the dissolution of Zn and uneven current distribution on the anode. Therefore, for the current study, we selected K3[Fe(CN)6] as an electrolyte additive that would help minimize the corrosion and dissolution of the Zn anode. In the alkaline electrolyte, [Fe(CN)6]3– was reduced to [Fe(CN)6]4– by the metallic Zn present in the Zn-Ni battery. Owing to its low solubility in the electrolyte, K4[Fe(CN)6] adhered to the active Zn anode, thereby inhibiting the aggregation and corrosion of Zn. Ultimately, the shape change of the anode was effectively eliminated, which improved the cycling life of the Zn-Ni battery by more than three times (i.e., from 124 cycles to more than 423 cycles). As for capacity retention, the Zn-Ni battery with the pristine electrolyte only exhibited 40% capacity retention after 85 cycles, while the Zn-Ni battery with the modified electrolyte (i.e., containing K3[Fe(CN)6]) showed 72% capacity retention. Moreover, unlike conventional organic additives that increase electrode polarization, the addition of K3[Fe(CN)6] not only significantly reduced the charge-transfer resistance in a simplified three-electrode system, but also improved the discharge capacity and rate performance of the Zn-Ni battery. Importantly, considering that this strategy was easy to achieve and minimized additional costs, K3[Fe(CN)6], as an electrolyte additive with almost no negative effect, has tremendous potential in commercial Zn-Ni batteries.![]()
相似文献
992.
Miklos Füzi Judit Pászti Ágnes Gyuris Erika Orosz János Minárovits Zsuzsa Szénási 《Structural chemistry》2008,19(2):203-208
The cell-free lysate of free-living amebae Naegleria gruberi and Naegleria fowleri were reported to elicit cytopathic effect in various cell lines that could be indefinitely transmitted by the culture media.
The causative agent showed sensitivity to treatments detrimental to proteins while resisted exposures damaging to nucleic
acids. Here we demonstrate that subsequent to exposure to N. gruberi lysate mild digestion with proteinase K reveals the presence of a protein band in HeLa cells absent from control cell lines.
Though the small quantity of this protein with enhanced resistance to proteinase K relative to the total protein content of
the sample has proved to date insufficient for its purification, we suppose that it is a human cellular protein that assumed
altered conformation in a prion-like fashion. The conformational conversion could have been trigerred by an ameba protein
in the lysate. In addition, we showed that HeLa cells treated with N. gruberi lysate display elevated cathepsin B activity which is assumed to be a secondary response to the accumulation of the proteinase
K-resistant protein. We propose that a number of degenerative sequelae following previous microbial infections in mammals
could have a similar pathomechanism. Moreover, epidemiological data strongly suggest that natural prion disease in sheep,
goat and cervids may also have an etiology linked to prior infection/colonization with a microbe, as it had already been proposed
by one of us. 相似文献
993.
Masashi Misawa Takayoshi Ogawa 《Calculus of Variations and Partial Differential Equations》2008,33(4):391-415
We show a regularity criterion to the harmonic heat flow from 2-dimensional Riemannian manifold M into a sphere. It is shown that a weak solution of the harmonic heat flow from 2-dimensional manifold into a sphere is regular
under the criterion
where BMO
r
is the space of bounded mean oscillations on M. A sharp version of the Sobolev inequality of the Brezis–Gallouet type is introduced on M. A monotonicity formula by the mean oscillation is established and applied for proving such a regularity criterion for weak
solutions as above. 相似文献
994.
995.
Luigi Ambrosio Alessio Figalli 《Calculus of Variations and Partial Differential Equations》2008,31(4):497-509
In this paper we improve the regularity in time of the gradient of the pressure field arising in Brenier’s variational weak
solutions (Comm Pure Appl Math 52:411–452, 1999) to incompressible Euler equations. This improvement is necessary to obtain
that the pressure field is not only a measure, but a function in . In turn, this is a fundamental ingredient in the analysis made by Ambrosio and Figalli (2007, preprint) of the necessary
and sufficient optimality conditions for the variational problem by Brenier (J Am Mat Soc 2:225–255, 1989; Comm Pure Appl
Math 52:411–452, 1999). 相似文献
996.
Leo Harrington showed that the second-order theory of arithmetic WKL
0 is -conservative over the theory RCA
0. Harrington’s proof is model-theoretic, making use of a forcing argument. A purely proof-theoretic proof, avoiding forcing,
has been eluding the efforts of researchers. In this short paper, we present a proof of Harrington’s result using a cut-elimination
argument.
相似文献
997.
Simon L. Kokkendorff 《Differential Geometry and its Applications》2008,26(6):638-644
We discuss the measure theoretic metric invariants extent, rendezvous number and mean distance of a general compact metric space X and relate these to classical metric invariants such as diameter and radius. In the final section we focus attention to the category of Riemannian manifolds. The main result of this paper is Theorem 4 stating that the round sphere of constant curvature 1 has maximal mean distance among Riemannian n-manifolds with Ricci curvature Ric?n−1, and that such a manifold is diffeomorphic to a sphere if the mean distance is close to . 相似文献
998.
Jean-Pierre Demailly Jun-Muk Hwang Thomas Peternell 《Journal of Geometric Analysis》2008,18(2):324-340
Let X be a compact complex manifold which is the image of a complex torus by a holomorphic surjective map A→X. We prove that X is Kähler and that up to a finite étale cover, X is a product of projective spaces by a torus. 相似文献
999.
We offer a new way of proving spectral mapping properties of delay semigroups in L
p
-history spaces with finitely many rationally depending delays based on an explicit construction of approximate eigenvectors.
This allows us to provide proper generalizations of the existing spectral mapping theorems.
Submitted: April 25, 2007. Accepted: November 5, 2007. 相似文献
1000.
The aim of this paper is to study, for L
1-data, the absorption problem of parabolic type : with Dirichlet boundary conditions and initial conditions. Here a satisfies the classical Leray-Lions hypotheses and β(x, ·) is the subdifferential ∂j(x, ·), where j is a convex function such that j(·, 0) = 0. Existence and uniqueness of an entropy solution is established.
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