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排序方式: 共有223条查询结果,搜索用时 218 毫秒
41.
Mirhashemihaghighi S León B Pérez Vicente C Tirado JL Stoyanova R Yoncheva M Zhecheva E Sáez Puche R Arroyo EM Romero de Paz J 《Inorganic chemistry》2012,51(10):5554-5560
A promising group of inorganic salts recently emerged for the negative electrode of advanced lithium-ion batteries. Manganese carbonate combines low weight and significant lithium storage properties. Electron paramagnetic resonance (EPR) and magnetic measurements are used to study the environment of manganese ions during cycling in lithium test cells. To observe reversible lithium storage into manganese carbonate, preparation by a reverse micelles method is used. The resulting nanostructuration favors a capacitive lithium storage mechanism in manganese carbonate with good rate performance. Partial substitution of cobalt by manganese improves cycling efficiency at high rates. 相似文献
42.
N. Andrés M. P. Arroyo H. Hinrichs K. Hinsch M. Quintanilla 《Experiments in fluids》2001,30(2):117-122
This paper investigates the feasibility of using holographic interferometry in wind tunnel flows for measuring velocity fields
rather than density or temperature fields. First results were obtained in a vortex street behind a cylinder at Re=190(U
∞=0.7 m/s). The light scattered from an illuminated fluid plane was holographically recorded twice with the same reference
beam. Using a time interval of 10 μs, local fluid displacements smaller than a few microns were recorded. The holographic
plate was placed in front and as close as possible to the fluid plane. The interferograms obtained from the hologram reconstruction
give information about one velocity component, at 45° with the illuminated plane. The alignment of the cylinder axis with
this 45° direction provided definite confirmation about the vortex street having a non-negligible axial velocity. The constant
velocity fluid region has proven to be very useful for quantifying the velocity information contained in the interferogram.
Received: 8 November 1999/Accepted: 14 March 2000 相似文献
43.
We consider Dirichlet boundary value problems for second order elliptic equations over polygonal domains. The coefficients of the equations under consideration degenerate at an inner point of the domain, or behave singularly in the neighborhood of that point. This behavior may cause singularities in the solution. The solvability of the problems is proved in weighted Sobolev spaces, and their approximation by finite elements is studied. This study includes regularity results, graded meshes, and inverse estimates. Applications of the theory to some problems appearing in quantum mechanics are given. Numerical results are provided which illustrate the theory and confirm the predicted rates of convergence of the finite element approximations for quasi-uniform meshes.
44.
A. O. Bazarko C. G. Arroyo K. T. Bachmann T. Bolton C. Foudas B. J. King W. C. Lefmann W. C. Leung S. R. Mishra E. Oltman P. Z. Quintas S. A. Rabinowitz F. J. Sciulli W. G. Seligman M. H. Shaevitz F. S. Merritt M. J. Oreglia B. A. Schumm R. H. Bernstein F. Borcherding H. E. Fisk M. J. Lamm W. Marsh K. W. B. Merritt H. M. Schellman D. D. Yovanovitch A. Bodek H. S. Budd P. de Barbaro W. K. Sakumoto T. Kinnel P. H. Sandler W. H. Smith 《Zeitschrift fur Physik C Particles and Fields》1995,65(2):189-198
We present the first next-to-leading-order QCD analysis of neutrino charm production, using a sample of 6090
– and
-induced opposite-sign dimuon events observed in the CCFR detector at the Fermilab Tevatron. We find that the nucleon strange quark content is suppressed with respect to the non-strange sea quarks by a factor =0.477
–0.053
+0.063
, where the error includes statistical, systematic and QCD scale uncertainties. In contrast to previous leading order analyses, we find that the strange seax-dependence is similar to that of the non-strange sea, and that the measured charm quark mass,m
c
=1.70±0.19 GeV/c2, is larger and consistent with that determined in other processes. Further analysis finds that the difference inx-distributions betweenxs(x) and
is small. A measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V
cd
|=0.232
–0.020
+0.018
is also presented. 相似文献
45.
46.
André C. Silva Alan Arroyo R. Bruce Richter Orlando Lee 《Discrete Mathematics》2019,342(11):3201-3207
The crossing number of a graph is the least number of crossings over all possible drawings of . We present a structural characterization of graphs with crossing number one. 相似文献
47.
Guadalupe Alcerreca Rubén Sanabria René Miranda Gabriel Arroyo Joaquín Tamariz Francisco Delgado 《合成通讯》2013,43(7):1295-1301
Several benzaldehydes were condensed with barbituric acid under infrared irradiation, in absence of solvent, affording the corresponding 5-benzylidene barbituric acids. 相似文献
48.
49.
F. J. Arroyo F. J. Carmona I. García De La Fuente J. A. González J. C. Cobos 《Journal of solution chemistry》2000,29(8):743-756
Excess molar volumes V
E
m at 25°C and atmospheric pressure over the entirecomposition range for binary mixtures of 1-heptanol with 2,5-dioxahexane, 2,5,8-trioxanonane,5,8,11-trioxapentadecane, 2,5,8,11-tetraoxadodecane,or 2,5,8,11,14-pentaoxapentadecane, and mixtures of 1-nonanol with 2,5-dioxahexane,3,6-dioxaoctane, 2,5,8-trioxanonane, 3,6,9-trioxaundecane, 5,8,11-trioxapentadecane,2,5,8,11-tetraoxadodecane, or 2,5,8,11,14-pentaoxapentadecane are reportedfrom densities measured with a vibrating-tube densimeter.V
E
m curves are nearlysymmetrical at about 0.5 mole fraction. Excess molar volumes are usually positive,indicating predominance of positive contributions to V
E
m from the disruption ofH bonds of alcohols and from physical interactions. When chain lengths ofboth components of the mixture are increased, the contribution from interstitialaccommodation appears to be sufficiently negative, such that V
E
m becomes negative(e.g., l-nonanol + 5,8,11-tetraoxapentadecane). 相似文献
50.
D. Arroyo P. Chamorro J.M. Amigó F.B. Rodríguez P. Varona 《The European physical journal. Special topics》2013,222(2):457-472
In this work, we apply ordinal analysis of time series to the characterisation of neuronal activity. Automatic event detection is performed by means of the so-called permutation entropy, along with the quantification of the relative cardinality of forbidden patterns. In addition, multivariate time series are characterised using the joint permutation entropy. In order to illustrate the suitability of the ordinal analysis for characterising neurophysiological data, we have compared the measures based on ordinal patterns of time series to the tools typically used in the context of neurophysiology. 相似文献