1,639 research outputs found
Lattice model theory of the equation of state covering the gas, liquid, and solid phases
The three stable states of matter and the corresponding phase transitions were obtained with a single model. Patterned after Lennard-Jones and Devonshires's theory, a simple cubic lattice model containing two fcc sublattices (alpha and beta) is adopted. The interatomic potential is taken to be the Lennard-Jones (6-12) potential. Employing the cluster variation method, the Weiss and the pair approximations on the lattice gas failed to give the correct phase diagrams. Hybrid approximations were devised to describe the lattice term in the free energy. A lattice vibration term corresponding to a free volume correction is included semi-phenomenologically. The combinations of the lattice part and the free volume part yield the three states and the proper phase diagrams. To determine the coexistence regions, the equalities of the pressure and Gibbs free energy per molecule of the coexisting phases were utilized. The ordered branch of the free energy gives rise to the solid phase while the disordered branch yields the gas and liquid phases. It is observed that the triple point and the critical point quantities, the phase diagrams and the coexistence regions plotted are in good agreement with the experimental values and graphs for argon
Estimating Shapley effects for moderate-to-large input dimensions
Sobol' indices and Shapley effects are attractive methods of assessing how a
function depends on its various inputs. The existing literature contains
various estimators for these two classes of sensitivity indices, but few
estimators of Sobol' indices and no estimators of Shapley effects are
computationally tractable for moderate-to-large input dimensions. This article
provides a Shapley-effect estimator that is computationally tractable for a
moderate-to-large input dimension. The estimator uses a metamodel-based
approach by first fitting a Bayesian Additive Regression Trees model which is
then used to compute Shapley-effect estimates. This article also establishes
posterior contraction rates on a large function class for this Shapley-effect
estimator and for the analogous existing Sobol'-index estimator. Finally, this
paper explores the performance of these Shapley-effect estimators on four
different test functions for moderate-to-large input dimensions and number of
observations.Comment: 19 pages, 3 figure
Development of a New Type Personal Dosemeter with Silicon Detector
開始ページ、終了ページ: 冊子体のページ付
Exact location of the multicritical point for finite-dimensional spin glasses: A conjecture
We present a conjecture on the exact location of the multicritical point in
the phase diagram of spin glass models in finite dimensions. By generalizing
our previous work, we combine duality and gauge symmetry for replicated random
systems to derive formulas which make it possible to understand all the
relevant available numerical results in a unified way. The method applies to
non-self-dual lattices as well as to self dual cases, in the former case of
which we derive a relation for a pair of values of multicritical points for
mutually dual lattices. The examples include the +-J and Gaussian Ising spin
glasses on the square, hexagonal and triangular lattices, the Potts and Z_q
models with chiral randomness on these lattices, and the three-dimensional +-J
Ising spin glass and the random plaquette gauge model.Comment: 27 pages, 3 figure
A Spin - 3/2 Ising Model on a Square Lattice
The spin - 3/2 Ising model on a square lattice is investigated. It is shown
that this model is reducible to an eight - vertex model on a surface in the
parameter space spanned by coupling constants J, K, L and M. It is shown that
this model is equivalent to an exactly solvable free fermion model along two
lines in the parameter space.Comment: LaTeX, 7 pages, 1 figure upon request; JETP Letters, in pres
Evidence for Isospin Violation and Measurement of C P Asymmetries in B → K ∗ ( 892 ) γ
We report the first evidence for isospin violation in B→K∗γ and the first measurement of the difference of CP asymmetries between B+→K*+γ and B0→K*0γ. This analysis is based on the data sample containing 772×106B¯B pairs that was collected with the Belle detector at the KEKB energy-asymmetric e+e− collider. We find evidence for the isospin violation with a significance of 3.1σ, Δ0+=[+6.2±1.5(stat)±0.6(syst)±1.2(f+−/f00)]%, where the third uncertainty is due to the uncertainty on the fraction of B+B− to B0¯B0 production in Υ(4S) decays. The measured value is consistent with predictions of the standard model. The result for the difference of CP asymmetries is ΔACP=[+2.4±2.8(stat)±0.5(syst)]%, consistent with zero. The measured branching fractions and CP asymmetries for charged and neutral B meson decays are the most precise to date. We also calculate the ratio of branching fractions of B0→K*0γ to B0s→ϕγ
Elevation of soluble interleukin-2 receptor levels in nasal allergy
To investigate soluble IL-2 receptor (sIL-2R) levels in nasal allergy, the sera and nasal secretions from patients with nasal allergy and from healthy subjects were subjected to a double-epitope enzyme-linked immunosorbent assay. Significant elevation of sIL-2R concentrations in the sera and nasal secretions was observed in the allergy patients (n = 26) compared with those of healthy subjects (n = 9). IL-2R-positive (CD25+) cells were observed in the crust formed in an allergic nasal mucosa. The concentration of sIL-2R in the sera correlated neither with the eosinophil count of the peripheral blood count nor with clinical severity. The concentration of sIL-2R in the nasal secretions was significantly higher compared with that in the sera from allergic patients (p < 0.01), whereas no significant difference was observed between sIL-2R levels in the sera and nasal sections from normal subjects. These findings indicate that sIL-2R plays an essential role in allergic processes by regulating IL-2R-positive cells recruited into the nasal mucosa
Critical phase of a magnetic hard hexagon model on triangular lattice
We introduce a magnetic hard hexagon model with two-body restrictions for
configurations of hard hexagons and investigate its critical behavior by using
Monte Carlo simulations and a finite size scaling method for discreate values
of activity. It turns out that the restrictions bring about a critical phase
which the usual hard hexagon model does not have. An upper and a lower critical
value of the discrete activity for the critical phase of the newly proposed
model are estimated as 4 and 6, respectively.Comment: 11 pages, 8 Postscript figures, uses revtex.st
Localization of Adenylate Kinase 4 in Mouse Tissues
Adenylate kinase (AK) is a key enzyme in the high-energy phosphoryl transfer reaction in living cells. Of its isoforms, AK4 has a similar sequence and subcellular localization to that of AK3 in the mitochondrial matrix. However, unlike AK3, AK4 lacks the guanosine triphosphate: adenosine monophosphate phosphotransferase activity. To elucidate the physiological role of AK4, we explored the protein localization of AK4 in various mouse tissues by immunohistochemical analysis. AK4 protein was detected in the kidney, liver, brain, heart, stomach, intestine, and gonads but not in the lung and spleen. Interestingly, cell-type specific expression was evident in the brain, gastrointestinal tract, and gonads. In the cerebellum, AK4 was detected in granular cells but not in Purkinje cell bodies. In the gastrointestinal tract, AK4 was highly expressed in epithelia. In the ovary, AK4 was detected in oocytes and corpora lutea. In the testis, AK4 was detected in spermatocytes but not in spermatogonia. Our findings demonstrate that AK4 localizes uniquely in a cell-type and tissue-specific manner in mouse tissues
- …