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1.
To date, the fastest lithium ion-conducting solid electrolytes known are the perovskite-type ABO3 oxide, with A = Li, La and B = Ti, lithium lanthanum titanate (LLTO)
Li3x La( 2 \mathord | / |
\vphantom 2 3 3 ) - x [¯]( 1 \mathord | / |
\vphantom 1 3 3 ) - x TiO3 {\rm Li}_{3x} {\rm La}_{\left( {{2 \mathord{\left/ {\vphantom {2 3}} \right. \kern-\nulldelimiterspace} 3}} \right) - x} \Box_{\left( {{1 \mathord{\left/ {\vphantom {1 3}} \right. \kern-\nulldelimiterspace} 3}} \right) - x} {\rm TiO}_3 and its structurally related materials. In this formula, [¯]\Box represents the vacancy. These materials have attracted much attention due to their application in lithium ion batteries used
as energy sources in microelectronic and information technologies. In addition to the well-established simple cubic, tetragonal
and orthorhombic perovskite type distorted cell structures, the hexagonal unit cell was reported in a recent study for Li0.5 La0.5 TiO3 − δ
, ( 0 £ d £ 0.06 )\left( {0 \le \delta \le 0.06} \right). We investigated the ionic conductivity in hexagonal La0.5 Li0.5 TiO3{\rm La}_{0.5} {\rm Li}_{0.5}\- {\rm TiO}_3 by molecular dynamics. We confirmed that ionic conductivity in this compound is due to the motion of lithium ions. We show
that both Arrhenius and Vogel–Tamman–Fulcher-type relationships could be used to express the high-temperature conductivity
of this compound. From our results, hexagonal LLTO exhibits almost 1.7–1.9 ×10 − 3 S cm − 1 at room temperature. Thus, due to its high ionic conductivity, this compound is expected to show some advantages in comparison
with the best conductors of this family, for usual applications of ionic conductors. 相似文献
3.
The temperature dependences of the quenching rate constants of the states
N 2 (${\rm C} \ {^{3}{
\rm \Pi }_{u}}${\rm C} \ {^{3}{
\rm \Pi }_{u}} v ′=0,1) by N 2 (X) and of the state
N 2 (${\rm C} \ {^{3}{
\rm \Pi }_{u}} \ v^{\prime}=0${\rm C} \ {^{3}{
\rm \Pi }_{u}} \ v^{\prime}=0) by O 2 (X) are studied.
Time-resolved light emission from the gas was analyzed in the temperature
range from 300 K to 210 K keeping the gas at constant density. In case of
quenching by N 2 (X), the quenching rate constant for the vibrational
level v ′= 0 increases by (13 ±3)% with gas cooling whereas the
quenching rate constant for v ′= 1 decreases by (5.0 ±2.5)% in this
temperature range. For quenching by O 2 (X), the quenching rate constant
decreases by (3 ±2)% with gas cooling. The temperature variation of
the N 2 (C 3Π u v ′=0) emission intensity for pure nitrogen
and dry air are calculated using the obtained quenching rate constants and
is compared with the experimental data available in the literature. 相似文献
4.
The damages triggered by ionizing radiation on chemical and biological targets depend on the survival probability of radicals
produced in clusters of ionization-excitation events. In this paper, we report on femtolysis (FEMTOsecond radioLYSIS) of pure
liquid water using an innovative laser produced high-energy, ultra-short electron bunches in the 2.5-15 MeV range and high
energy radiation femtochemistry (HERF) measurements. The short-time monitoring of a primary reducing radical, hydrated electron
e -aq^{-}_{aq}, has been performed in confined ionization spaces (nascent spurs). The calculated yield of hydrated electrons at early time,
G(e -aq) ETG({\rm e}^{-}_{aq})_{ET}, is estimated to be 6.5 ± 0.5 (number/100 eV) at t ~ 5 ps after the ultrafast energy deposition. This estimated value is high compare to (i) the available data of previous
works that used scavenging techniques; (ii) the predictions of stochastic water radiolysis modelling for which the initial
behaviour of hydrated electron is investigated in the framework of a classical diffusion regime of independent pairs. The
HERF developments give new insights into the early ubiquitous radical escape probability in nascent aqueous spurs and emphasize
the importance of short-lived solvent bridged electron-radical complexes
[H 3O +...{\rm H}_{3}{\rm O}^{+...}
e aq-{\rm e}_{aq}^{-} ..OH] nH2O{\rm OH}]_{n{\rm H}_2{\rm O}}
(non-independent pairs). A complete understanding of the
G(e -aq) ET{\rm e}^{-}_{aq})_{ET} value needs to account for quantum aspects of 1 s-like trapped electron ground state and neoformed
prototropic radicals that govern ultra-fast recombination processes within these non-independent pair configurations. Femtolysis
data
emphasize that within a time-dependent non-diffusion regime, spatio-temporal correlations between hydrated electron and nearest
neighbours OH radical or hydrated proton (H 3O +{\rm H}_{3}{\rm O}^{+}) would assist ultrafast anisotropic 1D recombination within solvent bridged electron-radical complexes. The emerging HERF
domain would provide guidance for understanding of ultrashort-lived sub-structure of tracks and stimulate future semi-quantum
simulations on prethermal radical reactions. 相似文献
5.
Summary Reflectivity measurements have been done on doped n-type HgCr 2Se 4 ( n≈(10 15÷10 19) cm −3), at various temperatures ((4÷300) K) in the infra-red range
. The spectra show the structure of a plasma edge and reststrahlbands. Data have been analysed by a Kramers-Kronig procedure.
The deduced dynamical conductivity shows an anomaly near the plasma frequency ω p. The transmitivity measurements show a strong temperature dependence of the conduction band.
Paper presented at the ?V International Conference on Ternary and Multinary Compounds?, held in Cagliari, September 14–16,
1982. 相似文献
6.
Three-dimensional quantitative structure–activity relationship (3D-QSAR) models were developed based on comparative molecular
field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA), on a series of 43 hydroxyethylamine
derivatives, acting as potent inhibitors of β-site amyloid precursor protein (APP) cleavage enzyme (BACE-1). The crystal structure of the BACE-1 enzyme (PDB ID: 2HM1)
with one of the most active compound 28 was available, and we assumed it to be the bioactive conformation of the studied series, for 3D-QSAR analysis. Statistically
significant 3D-QSAR model was established on a training set of 34 compounds, which were validated by a test set of 9 compounds.
For the best CoMFA model, the statistics are, r
2 = 0.998, r2cv = 0.810{r^{2}_{\rm cv} = 0.810} , n = 34 for the training set and r2pred = 0.934{r^{2}_{\rm pred} = 0.934} , n = 9 for the test set. For the best CoMSIA model (combined steric, electrostatic, hydrophobic, and hydrogen bond donor fields),
the statistics are r
2 = 0.978, r2cv = 0.754{r^{2}_{\rm cv} = 0.754} , n = 34 for the training set and r2pred = 0.750{r^{2}_{\rm pred} = 0.750} , n = 9 for the test set. The resulting contour maps, produced by the best CoMFA and CoMSIA models, were used to identify the
structural features relevant to the biological activity in this series of analogs. The data generated from the present study
will further help to design novel, potent, and selective BACE-1 inhibitors. 相似文献
7.
We present the results of elliptic flow for the collision of nearly symmetric nuclei ( 10Ne 20+ 13Al 27_{10}{\rm Ne}^{20}+\,_{13}{\rm Al}^{27}, 18Ar 40+ 21Sc 45_{18}{\rm Ar}^{40}+\,_{21}{\rm Sc}^{45}, 30Zn 64+ 28Ni 58_{30}{\rm Zn}^{64}+\,_{28}{\rm Ni}^{58}, 36Kr 86+ 41Nb 93_{36}{\rm Kr}^{86}+\,_{41}{\rm Nb}^{93}) using the quantum molecular dynamics (QMD) model. General features of elliptic flow are investigated with the help of theoretical
simulations. The simulations are performed at beam energies between 45 and 105 MeV /nucleon. A significant change can be seen
from in-plane to out-of-plane elliptic flow of different fragments with incident energy. A comparison with experimental data
is also made. Further, we show that elliptic flow for different fragments follows power-law dependence as given by the function
C( Atot) tC{(A_{\rm tot})^\tau}. 相似文献
8.
With the discovery of Dark Energy, Λ DE, there is now a universal length scale, lDE= c/(L DE G) 1/2{\ell_{\rm DE}=c/(\Lambda_{\rm DE} G)^{1/2}}, associated with the universe that allows for an extension of the geodesic equations of motion. In this paper, we will study
a specific class of such extensions, and show that contrary to expectations, they are not automatically ruled out by either
theoretical considerations or experimental constraints. In particular, we show that while these extensions affect the motion
of massive particles, the motion of massless particles are not changed; such phenomena as gravitational lensing remain unchanged.
We also show that these extensions do not violate the equivalence principal, and that because lDE=14010 800820{\ell_{\rm DE}=14010^{800}_{820}} Mpc, a specific choice of this extension can be made so that effects of this extension are not be measurable either from
terrestrial experiments, or through observations of the motion of solar system bodies. A lower bound for the only parameter
used in this extension is set. 相似文献
9.
To determine nonspherical angular-momentum amplitudes in hadrons at long ranges (low Q 2), data were taken for the p(ˉ e, e'p)π 0 reaction in the Δ region at Q
2 = 0.060 (GeV/ c) 2 utilizing the magnetic spectrometers of the A1 Collaboration at MAMI. The results for the dominant transition magnetic dipole
amplitude and the quadrupole to dipole ratios at W = 1232 MeV are
, Re(
)%, and Re(
)%. These disagree with predictions of constituent quark models but are in reasonable agreement with lattice calculations
with nonlinear (chiral) pion mass extrapolations, with chiral effective field theory, and with dynamical models with pion
cloud effects. These results confirm the dominance, and general Q 2 variation, of the pionic contribution at large distances. 相似文献
10.
We determine the extreme points of the tracial state space of the noncommutative 3-sphere Calg( Sq3){C^{\rm alg}(S_{\theta}^{3})} when the deformation parameter θ is an irrational number. 相似文献
11.
One-dimensional system of Brownian motions called Dyson’s model is the particle system with long-range repulsive forces acting
between any pair of particles, where the strength of force is β/2 times the inverse of particle distance. When β=2, it is realized as the Brownian motions in one dimension conditioned never to collide with each other. For any initial
configuration, it is proved that Dyson’s model with β=2 and N particles,
$\mbox {\boldmath $\mbox {\boldmath
, is determinantal in the sense that any multitime correlation function is given by a determinant with a continuous kernel.
The Airy function
(z){\rm Ai}(z)
is an entire function with zeros all located on the negative part of the real axis ℝ. We consider Dyson’s model with β=2 starting from the first N zeros of
Ai( z){\rm Ai}(z)
, 0> a
1> ⋅⋅⋅> a
N
, N≥2. In order to properly control the effect of such initial confinement of particles in the negative region of ℝ, we put the
drift term to each Brownian motion, which increases in time as a parabolic function: Y
j
( t)= X
j
( t)+ t
2/4+{ d
1+∑
ℓ=1
N
(1/ a
ℓ
)} t,1≤ j≤ N, where
d1=Ai¢(0)/Ai(0)d_{1}={\rm Ai}'(0)/{\rm Ai}(0)
. We show that, as the N→∞ limit of
$\mbox {\boldmath $\mbox {\boldmath
, we obtain an infinite particle system, which is the relaxation process from the configuration, in which every zero of
(z){\rm Ai}(z)
on the negative ℝ is occupied by one particle, to the stationary state
m Ai\mu_{{\rm Ai}}
. The stationary state
m Ai\mu_{{\rm Ai}}
is the determinantal point process with the Airy kernel, which is spatially inhomogeneous on ℝ and in which the Tracy-Widom
distribution describes the rightmost particle position. 相似文献
13.
In this paper, we study the generalized quantum double construction for paired Hopf algebras with particular attention to
the case when the generalized quantum double is a Hopf algebra with projection. Applying our theory to a coquasitriangular
Hopf algebra ( H, σ), we see that H has an associated structure of braided Hopf algebra in the category of Yetter-Drinfeld modules over , where H
σ
is a subHopf algebra of H
0, the finite dual of H. Specializing to the quantum group H = SL
q
( N), we find that H
σ
is , so that the duality between these quantum groups is just the evaluation map. Furthermore, we obtain explicit formulas for
the braided Hopf algebra structure of SL
q
( N) in the category of left Yetter-Drinfeld modules over .
The second author held a postdoctoral fellowship at Mount Allison University from 2005 to 2007 and would like to thank Mount
Allison for their warm hospitality. Support for the first author’s research and partial support for the postdoctoral position
of the second author came from an NSERC Discovery Grant. The second author now holds research support from Grant 434/1.10.2007
of CNCSIS. 相似文献
14.
A new solid substrate-room temperature phosphorescence (SS-RTP) method for the determination of trace manganese (II) has been
established. It bases on the fact that fullerol (R) emits strong and stable room temperature phosphorescence (RTP) on filter
paper substrate. H 2O 2 can oxidize R to cause the SS-RTP quenching. But manganese (II) can obstruct H 2O 2 to oxidize R, and enhance the RTP of R. α,α′-Bipyridine (Bipy) can sensitize the RTP. After adding Bipy, the Δ I
p enhances 7 times than that without Bipy. Under the optimum conditions, the linear dynamic range of this method is 0.016–1.12 pg spot −1 with a detection limit (L.D.) of 4.6 fg spot −1 ( is the absolute mass of Mn 2+), and the regression equation of working curve is Δ I
p=25.20 + 63.55 (pg spot −1), n=6, r=0.9983. For 0.016 and 1.12 pg spot −1 Mn 2+, RSDS are 4.3 and 4.8%, respectively ( n=7). This method has been applied to the determination of trace manganese (II) in actual sample with high sensitivity and
good selection. And the reaction mechanism of SS-RTP is discussed. 相似文献
16.
The experimental determination of the radial electric field E
r and the associated E × B drift velocity at the edge of RFX is presented and possible mechanisms responsible for its generation are discussed. E
r measurements by means of an array of Langmuir probes and those deduced from Doppler spectroscopy of impurity lines agree
fairly well. In particular the rotation velocity of the plasma edge has been determined from the Doppler shift of a C III
emission line. The observation of other ions characterised by different radial positions, such as B IV and C V, has allowed
an estimate of the velocity shear. Typical values of plasma rotation at the edge are around 10 km/s while the velocity shear
is of the order of (10 5−10 6)s −1 in the spontaneous layer, a few cm thick, usually observed in standard discharges. Plasma rotation has been artificially
modified by both positive and negative edge biasing and the associated increase or decrease of the fluid velocity is well
in agreement with the radial electric field change. The modification of E
r during edge biasing and Pulsed Poloidal Current Drive (PPCD) are also reported and interpreted within a momentum balance
model. Analytical and self-consistent Monte Carlo models at the plasma edge suggest that impurities have a relevant role in
the generation of the radial electric field, due to their relatively large Larmor radius.
Presented at the Workshop on Role of Electric Fields in Plasma Confinement and Exhaust, Budapest, 18–19 June 2000. 相似文献
17.
Let S
2 be the 2-dimensional unit sphere and let J
α
denote the nonlinear functional on the Sobolev space H
1( S
2) defined by
$J_\alpha(u) = \frac{\alpha}{16\pi}\int_{S^2}|\nabla u|^2\, d\mu_0 + \frac{1}{4\pi} \int_{S^2} u\, d \mu_0 -{\rm ln} \int_{S^2} e^{u}
\, \frac{d \mu_0}{4\pi},$J_\alpha(u) = \frac{\alpha}{16\pi}\int_{S^2}|\nabla u|^2\, d\mu_0 + \frac{1}{4\pi} \int_{S^2} u\, d \mu_0 -{\rm ln} \int_{S^2} e^{u}
\, \frac{d \mu_0}{4\pi}, 相似文献
18.
We consider a modification of the three-dimensional Navier–Stokes equations and other hydrodynamical evolution equations with
space-periodic initial conditions in which the usual Laplacian of the dissipation operator is replaced by an operator whose
Fourier symbol grows exponentially as e |k|/kd{{{\rm e}^{|k|/k_{\rm d}}}} at high wavenumbers | k|. Using estimates in suitable classes of analytic functions, we show that the solutions with initially finite energy become
immediately entire in the space variables and that the Fourier coefficients decay faster than e -C(k/kd) ln(|k|/kd){{{\rm e}^{-C(k/k_{\rm d})\,{\rm ln}(|k|/k_{\rm d})}}} for any C < 1/(2 ln 2). The same result holds for the one-dimensional Burgers equation with exponential dissipation but can be improved:
heuristic arguments and very precise simulations, analyzed by the method of asymptotic extrapolation of van der Hoeven, indicate
that the leading-order asymptotics is precisely of the above form with C = C
* = 1/ ln 2. The same behavior with a universal constant C
* is conjectured for the Navier–Stokes equations with exponential dissipation in any space dimension. This universality prevents
the strong growth of intermittency in the far dissipation range which is obtained for ordinary Navier–Stokes turbulence. Possible
applications to improved spectral simulations are briefly discussed. 相似文献
19.
The axial coupling and the magnetic moment of D
∗-meson or, more specifically, the couplings gD*Dpg_{D^{\ast}D\pi} and gD*Dgg_{D^{\ast}D\gamma }, encode the non-perturbative QCD effects describing the decays D
∗→ Dπ and D
∗→ Dγ. We compute these quantities by means of lattice QCD with N
f=2 dynamical quarks, by employing the Wilson (“ clover”) action. On our finer lattice ( a≈0.065 fm) we obtain gD*Dp+=20±2g_{D^{\ast}D\pi^{+}}=20\pm2, and gD*0 D0g=2.0±0.6 GeV -1g_{D^{\ast0} D^{0}\gamma}=2.0\pm 0.6~{\rm GeV}^{-1}. This is the first determination of gD*0 D0gg_{D^{\ast0} D^{0}\gamma} on the lattice. We also provide a short phenomenological discussion and the comparison of our result with experiment and
with the results quoted in the literature. 相似文献
20.
Ground-state magnetic-dipole moments (μ) of 30-32Al and
electric quadrupole moments (Q) of 31,32Al have been measured
with the β-NMR method using spin-polarized radioactive-isotope
beams produced in projectile-fragmentation reactions. Beams of
30-32Al were obtained by using RIKEN projectile-fragment
separator RIPS after the fragmentation of 40Ar projectiles at an
energy of E = 95A MeV on a 93Nb target. The obtained
μ exp[ 30-32Al] and
values agree well with shell-model calculations within the sd
shell using the USD interaction. Also, Q exp[ 31Al]
was found to be small. Thus, we can conclude that these aluminum
isotopes are located outside the island of inversion. 相似文献
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