4,432 research outputs found
Elementary Proofs Of Two Theorems Involving Arguments Of Eigenvalues Of A Product Of Two Unitary Matrices
We give elementary proofs of two theorems concerning bounds on the maximum
argument of the eigenvalues of a product of two unitary matrices --- one by
Childs \emph{et al.} [J. Mod. Phys., \textbf{47}, 155 (2000)] and the other one
by Chau [arXiv:1006.3614]. Our proofs have the advantages that the necessary
and sufficient conditions for equalities are apparent and that they can be
readily generalized to the case of infinite-dimensional unitary operators.Comment: 8 pages in Revtex 4.1 preprint format, to appear in Journal of
Inequalities and Application
Simultaneous multiwavelength study of the reaction of phenolphthalein with sodium hydroxide
A photodiode array (PDA) spectrophotometer was used to study the
fading reaction of phenolpthalein in dilute sodium hydroxide
solution. The principal component analysis (PCA) method was
employed to identify the number of light absorbing species in the
kinetics system. The target factor analysis (TFA) procedure,
coupled with the Broyden-Fletcher-Goldfard-Shanno (BFGS)
optimization method, was applied to the observed data to deduce the
rate constants and the concentration-time profile of the reaction. The
internal referencing method was shown to be essential in improving
the quality of data obtained by a single beam PDA
spectrophotomer
On the Second-Order Statistics of Correlated Cascaded Rayleigh Fading Channels
The second-order statistics of two correlated cascaded (double) Rayleigh fading channels are analyzed, where different relevant second-order cross-correlation functions of in-phase and quadrature components of the cascaded Rayleigh channels are derived. The level crossing rate (LCR) and average fade duration (AFD) of the cascaded channels are evaluated, and a single-integral form of the LCR is derived. Numerical results of the LCR and AFD are presented, and the effect of the correlation is illustrated
Relation Between Quantum Speed Limits And Metrics On U(n)
Recently, Chau [Quant. Inform. & Comp. 11, 721 (2011)] found a family of
metrics and pseudo-metrics on -dimensional unitary operators that can be
interpreted as the minimum resources (given by certain tight quantum speed
limit bounds) needed to transform one unitary operator to another. This result
is closely related to the weighted -norm on . Here we
generalize this finding by showing that every weighted -norm on
with 1\le p \le \limitingp induces a metric and a
pseudo-metric on -dimensional unitary operators with quantum
information-theoretic meanings related to certain tight quantum speed limit
bounds. Besides, we investigate how far the correspondence between the
existence of metrics and pseudo-metrics of this type and the quantum speed
limits can go.Comment: minor amendments, 6 pages, to appear in J.Phys.
How Does Competition Help Future Learning in Serious Games? An Exploratory Study in Learning Search Engine Optimization
Serious games, many of which are multi-player games, have been commonly used in information technology education and training. Competition can be intuitively associated with games; however, it is not always considered as a necessary attribute of serious games. Particularly, the learning impact results of competition are mixed. Challenge and control are two game attributes that are highly relevant to competition. With the use of a multi-player serious game, SEO War, this study aims to explore the relationships among competition, perceived control, perceived challenge, and self-efficacy in a game-based learning environment. Particularly, it investigates whether competition leads to self-efficacy. It also examines whether perceived challenge and perceived control mediate the relationship between competition and self-efficacy in serious games. This study contributes to the expanding literature on selecting important attributes for serious games, and it advances our understanding of the mechanism of how competition leads to self-efficacy. Moreover, it will help game designers decide on important game attributes through which games can be enhanced
Flavor SU(3) symmetry and QCD factorization in and decays
Using flavor SU(3) symmetry, we perform a model-independent analysis of
charmless decays. All the relevant
topological diagrams, including the presumably subleading diagrams, such as the
QCD- and EW-penguin exchange diagrams and flavor-singlet weak annihilation
ones, are introduced. Indeed, the QCD-penguin exchange diagram turns out to be
important in understanding the data for penguin-dominated decay modes. In this
work we make efforts to bridge the (model-independent but less quantitative)
topological diagram or flavor SU(3) approach and the (quantitative but somewhat
model-dependent) QCD factorization (QCDF) approach in these decays, by
explicitly showing how to translate each flavor SU(3) amplitude into the
corresponding terms in the QCDF framework. After estimating each flavor SU(3)
amplitude numerically using QCDF, we discuss various physical consequences,
including SU(3) breaking effects and some useful SU(3) relations among decay
amplitudes of and .Comment: 47 pages, 3 figures, 28 table
Analysis of Two-Body Decays of Charmed Baryons Using the Quark-Diagram Scheme
We give a general formulation of the quark-diagram scheme for the nonleptonic
weak decays of baryons. We apply it to all the decays of the antitriplet and
sextet charmed baryons and express their decay amplitudes in terms of the
quark-diagram amplitudes. We have also given parametrizations for the effects
of final-state interactions. For SU(3) violation effects, we only parametrize
those in the horizontal -loop quark diagrams whose contributions are solely
due to SU(3)-violation effects. In the absence of all these effects, there are
many relations among various decay modes. Some of the relations are valid even
in the presence of final-state interactions when each decay amplitude in the
relation contains only a single phase shift. All these relations provide useful
frameworks to compare with future experiments and to find out the effects of
final-state interactions and SU(3) symmetry violations.Comment: 28 pages, 20 Tables in landscape form, 4 figures. Main changes are:
(i) some errors in the Tables and in the relations between the quark-diagram
amplitudes of this paper and those of Ref.[10] are corrected, (ii)
improvements are made in the presentation so that comparisons with previous
works and what have been done to include SU(3) breaking and final-state
interactions are more clearly stated; to appear in the Physical Review
Implications of Recent Measurements
The recent measurements of the color-suppressed modes imply non-vanishing relative final-state interaction (FSI)
phases among various decay amplitudes. Depending on whether or
not FSIs are implemented in the topological quark-diagram amplitudes, two
solutions for the parameters and are extracted from data using
various form-factor models. It is found that is not universal:
and with a relative phase
of order between and . If FSIs are not included in
quark-diagram amplitudes from the outset, and
will become smaller. The large value of compared to
or naive expectation implies the importance of
long-distance FSI contributions to color-suppressed internal -emission via
final-state rescatterings of the color-allowed tree amplitude.Comment: 17 pages. The Introduction is substantially revised and the order of
the presentation in Sec. 2 is rearranged. To appear in Phys. Re
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Low-Frequency Medium Power Capacitor-Free Self-Resonant Wireless Power Transfer
入院患者のサルモネラ保菌率およびその分離のための増菌培地の比較
The efficiencies of Rappaport medium, strontium chloride, strontium selenite and selenite F broths for enrichment in the isolation of salmonellas from human stools were compared. The study showed that Rappaport medium when used in conjunction with strontium selenite broth gave the most satisfactory result, because they covered the isolation of a wider range of salmonellas. With these media, the carriage rate of Salmonella serotypes of 3,325 hospital patients who were admitted without complaints of diarrhoea or gastroenteritis or enteric fever, were tested. The result revealed that 5.6% of them carried Salmonella serotypes ranging from those that may produce food-poisoning to those which are causal agents of enteric fever. Moreover, patients who were infected with the liver-fluke, Clonorchis sinensis, had a higher carriage rate than those who were infected with other intestinal parasites or non-infected.サルモネラ分離に際してRappaport培地,strontium chlorideブイヨン,strontium seleniteブイヨンおよびselenite Fブイヨンの4種の増菌培地を用い,その成績を比較した.その結果,Rappaport培地にstrontium seleniteブイヨンを併用すると,サルモネラの各種類の分離に最も満足すべき成績がえられた.これらの培地を用いて,下痢を全く伴わない患者,胃腸炎あるいはチフス性疾患の患者3,325名についてサルモネラ保菌率を検査した.その結果,22の血清型に属する189株のサルモネラを分離した.検出率は5.6%である.その血清型は,食中毒の原因と推定されたものから,チフス性疾患の原因菌に至るさまぎまの型が含まれていたが,最も多く分離されたのはS. derbyとS. anatumであった.また,Clonorchis sinensisに感染していた患者は,他の腸寄生虫感染者あるいは非感染者より高率にサルモネラを保有していた
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