Search

It is well-known that the life span of solutions to Kirchhoff equations tends to infinity when initial data tend to zero. These results are usually referred to as almost global existence, at least in a neighborhood of the null solution. Here we extend this result by showing that the life span of solutions is lower semicontinuous, and in particular it tends to infinity whenever initial data tend to some limiting datum that originates a global solution. We also provide an estimate from below for the life span of solutions when initial data are close to some of the classes of data for which global existence is known, namely data with finitely many Fourier modes, analytic data, and quasi-analytic data. [ABSTRACT FROM AUTHOR]

An |$L^2$| version of the classical Denjoy–Carleman theorem regarding quasi-analytic functions was proved by P. Chernoff on |$\mathbb {R}^n$| using iterates of the Laplacian. We give a simple proof of this theorem that generalizes the result on |$\mathbb {R}^n$| for any |$p\in [1, 2]$|⁠. We then extend this result to Riemannian symmetric spaces of compact and noncompact type for |$K$| -biinvariant functions. [ABSTRACT FROM AUTHOR]

In this paper, we prove that the identity map for the smoothly bounded pseudoconvex domain of finite type in C 2 extends to a bi-Hölder map between the Euclidean boundary and Gromov boundary. As an application, we show the bi-Hölder boundary extensions for quasi-isometries between these domains. Moreover, we get a more accurate index of the Gehring–Hayman type theorem for the bounded m-convex domains with Dini-smooth boundary. [ABSTRACT FROM AUTHOR]

Inspired by some iterative algorithms useful for proving the real analyticity (or the Gevrey regularity) of a solution of a linear partial differential equation with real‐analytic coefficients, we consider the following question. Given a smooth function defined on [a,b]⊂R$[a,b]\subset {\mathbb {R}}$ and given an increasing divergent sequence dn$d_n$ of positive integers such that the derivative of order dn$d_n$ of f has a growth of the type Mdn$M_{d_n}$, when can we deduce that f is a function in the Denjoy–Carleman class CM([a,b])$C^M([a,b])$? We provide a positive result and show that a suitable condition on the gaps between the terms of the sequence dn$d_n$ is needed. [ABSTRACT FROM AUTHOR]

It is well established that politically experienced candidates are electorally more successful than "novices." However, methodological challenges have prevented scholars from establishing how much of this is attributable to voters who use political experience as a cue to infer competence. Further, information about political experience may decrease the weight voters place on other, less informative cues. In a natural quasi-experiment, I exploit the condition that—in the 2015 Swiss national elections—information about candidates' political experience on party ballots varied approximately at random. In line with cue-based accounts, I show that political experience is most of an asset if it is mentioned on the ballot. Contrary to expectations, however, these cues do not crowd out group-membership cues such as those based on a candidate's migration background. The results from two original candidate choice survey experiments, designed to measure causal processes, further corroborate these findings. [ABSTRACT FROM AUTHOR]

In the present paper, we form a sharp inequality for a doubly warped product submanifold of a Riemannian manifold of nearly quasi-constant curvature. [ABSTRACT FROM AUTHOR]

The concept of 2-normed spaces and 2-Banach spaces are considered as a generalization of normed and Banach spaces. In the present paper, we have studied the existence of square roots and quasi square roots of some elements of a 2-Banach algebra. Moreover, the relation between nth roots and quasi nth roots of elements in 2-Banach algebras are considered. [ABSTRACT FROM AUTHOR]

A quasi-analytical solution on the minimum length and its corresponding system energy is proposed for the stable multi-layer folded graphene wrinkles (FGWs). The quasi-analytical solution shows that: (1) at a certain threshold height, a single-layer FGW becomes energetically favorable compared to a standing graphene wrinkle. (2) All the geometrical properties of single-layer FGW reproduce in the double-layer FGWs, which is considered as the typical configuration for predicting the multi-layer folded FGWs. (3) Parametric studies show that the increased bending stiffness per length promotes the minimum graphene length while the case is reversed for the increased adhesion energy density. Both of the increased bending stiffness per length and adhesion energy density lead to the decreased system energy for the stable folded structure, while the system energy is less sensitive to the variation of adhesion energy density compared to that of the bending stiffness per length. Besides, molecular mechanics simulation shows that the present model has high accuracy on evaluating the system energy and the configuration for multi-layer FGWs. [ABSTRACT FROM AUTHOR]

Let S be a ternary semigroup. In this article we introduce our notation and prove some elementary properties of a pair ideal (I, J) of a ternary semigroup S and give some characterizations of the minimality of pair left (right) and middle ideal in ternary semigroup. [ABSTRACT FROM AUTHOR]

Exploiting this article, we provide the coefficient estimate with m-th root transform for a class defined by Hohlov operator using quasi-subordination for conic domains. The authors sincerely hope this article will revive this concept and encourage the other researchers to work in this quasi subordination in the near future in the area of complex function theory. [ABSTRACT FROM AUTHOR]

Background: The aims of the present study were to assess changes in weight status between the first and last year of primary education among children with overweight/obesity in response to locally implemented school-based prevention programs, and to assess the influence of process indicators, expressed as child-staff ratios (CSRs), on these changes.Methods: To meet the study objectives, a quasi-experimental design was used. Four municipalities that systematically monitored the weight status of schoolchildren and participated in the "Vivons en Forme" program agreed to provide the data available in their school medical service records. The local implementers involved in training sessions were mainly municipal staff in charge of serving midday school meals, which is compulsory in France, and those in charge of designing and facilitating creative, interactive activities at school between and after classes. CSRs were determined by occupation (school catering service/facilitator of extracurricular activities) and training session (healthy eating/physical activity) in each municipality program, and classified as low (1-5 children per adult) or moderate.Results: During the 4 years of primary education, weight status improved in half of the children with overweight/obesity, and worsened in 6.6% of children with overweight/normal weight. In children who remained overweight, the BMI z-score diminished over time. Estimates of the positive 4-year weight changes were related to low CSRs in locally implemented variations of the program. Estimates increased with age and were significantly higher in low-to-moderate CSR multicomponent interventions than moderate CSR single-component intervention (reference). The moderate CSR multicomponent intervention had a similar effect as the reference. The estimated negative weight change decreased with age.Conclusions: Our findings suggest that training ancillary school staff in experiential-focused interventions for healthy eating and physical activity in locally implemented school-based programs contributed positively to reducing childhood obesity during the four years of primary education without interfering with educational activities. The results also provide preliminary evidence that low CSRs could be pivotal for optimal outcomes, especially in deprived areas. [ABSTRACT FROM AUTHOR]

Copyright of Diyala Journal for Pure Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mathematical Physics, Analysis, Geometry (18129471) is the property of B Verkin Institute for Low Temperature Physics & Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, degenerate perturbation theory through second order is used to characterize the vicinity of a three state conical intersection. This report extends our recent demonstration that it is possible to describe the branching space (in which the degeneracy is lifted linearly) and seam space (in which the degeneracy is preserved) in the vicinity of a two state conical intersection using second order perturbation theory. The general analysis developed here is based on a group homomorphism approach. Second order perturbation theory, in conjunction with high quality ab initio electronic structure data, produces an approximately diabatic Hamiltonian whose eigenenergies and eigenstates can accurately describe the three adiabatic potential energy surfaces, the interstate derivative couplings, and the branching and seam spaces in their full dimensionality. The application of this approach to the minimum energy three state conical intersection of the pyrazolyl radical demonstrates the potential of this method. A Hamiltonian comprised of the ten characteristic (linear) parameters and over 300 second order parameters is constructed to describe the branching space associated with a point of conical intersection. The second order parameters are determined using data at only 30 points. In the vicinity of the conical intersection the energy and derivative couplings are well reproduced and the singularity in the derivative coupling is analyzed. [ABSTRACT FROM AUTHOR]

Quasiharmonic models with Tersoff [Phys. Rev. B 38, 9902 (1988)] interatomic potential are used to study the thermodynamic properties of crystalline silicon. It is shown that, compared to the molecular dynamics simulation data, the reciprocal space quasiharmonic model accurately predicts the thermal properties for temperatures up to 800 K. For higher temperatures, anharmonic effects become significant. With a significantly higher computational cost, the results from the real space quasiharmonic model approach the results from the reciprocal space quasiharmonic model as the number of atoms increases. The local quasiharmonic model does not accurately describe the thermal properties as it neglects the vibrational coupling of the atoms. We also investigate the effect of the strain on the thermodynamic properties. The variation of the thermodynamic properties with temperature under a tension, compression, and a shear deformation state is computed. [ABSTRACT FROM AUTHOR]

We have designed and fabricated a set of AlGaAs multilayer waveguides, which can serve as a source of entangled photons at 1.55 μm through parametric fluorescence. In our scheme two counterpropagating, orthogonally polarized signal/idler modes are nonlinearly generated by a pump wave impinging on the upper surface of the waveguide. To check the compliance with design specifications on phase-matching wavelength and parametric gain, we have systematically measured effective indices and surface-emitting second-harmonic generation, respectively. This characterization allowed us to single out a nominal sample with optimum performances, which we numerically modeled for counterpropagating parametric fluorescence. We predict a pair generation efficiency ηPF=4×10-13 (signal photons per pump photon). For a 1 W (peak), 100 ns pump pulse at normal incidence, this corresponds to about 14 photons per dark count with state-of-the-art avalanche photodiodes. [ABSTRACT FROM AUTHOR]

The article presents the front cover of the periodical; a list of its editorial board members, including Christopher W. Parker, Linus Kramer and John S. Wilson; along with the copyright information and table of content of the periodical.

Abstract A detailed description of the structure of two-ended arc-transitive digraphs is given. It is also shown that several sets of conditions, involving such concepts as Property Z, local quasi-primitivity and prime out-valency, imply that an arc-transitive digraph must be highly-arc-transitive. These are then applied to give a complete classification of two-ended highly-arc-transitive digraphs with prime in- and out-valencies. [ABSTRACT FROM AUTHOR]

This paper presents a numerical method to implement the parameter estimation method using response statistics that was recently formulated by the authors. The proposed approach formulates the parameter estimation problem of Itô drift diffusions as a nonlinear least-squares problem. To avoid solving the model repeatedly when using an iterative scheme in solving the resulting least-squares problems, a polynomial surrogate model is employed on appropriate response statistics with smooth dependence on the parameters. The existence of minimizers of the approximate polynomial least-squares problems that converge to the solution of the true least square problem is established under appropriate regularity assumption of the essential statistics as functions of parameters. Numerical implementation of the proposed method is conducted on two prototypical examples that belong to classes of models with a wide range of applications, including the Langevin dynamics and the stochastically forced gradient flows. Several important practical issues, such as the selection of the appropriate response operator to ensure the identifiability of the parameters and the reduction of the parameter space, are discussed. From the numerical experiments, it is found that the proposed approach is superior compared to the conventional approach that uses equilibrium statistics to determine the parameters. [ABSTRACT FROM AUTHOR]

We study the impact of noise on the rate dependent transitions in a noisy bistable oscillator using a thermoacoustic system as an example. As the parameter—the heater power—is increased in a quasi-steady manner, beyond a critical value, the thermoacoustic system undergoes a subcritical Hopf bifurcation and exhibits periodic oscillations. We observe that the transition to this oscillatory state is often delayed when the control parameter is varied as a function of time. However, the presence of inherent noise in the system introduces high variability in the characteristics of this critical transition. As a result, if the value of the system variable—the acoustic pressure—approaches the noise floor before the system crosses the unstable manifold, the effect of rate on the critical transition becomes irrelevant in determining the transition characteristics, and the system undergoes a noise-induced tipping to limit-cycle oscillations. The presence of noise-induced tipping makes it difficult to identify the stability regimes in such systems by using stability maps for the corresponding deterministic system. [ABSTRACT FROM AUTHOR]

Abstract In [13] , initially motivated by questions about the Hodge line bundle of a Hodge-type Shimura variety, we singled out a generalization of the notion of minuscule character which we termed quasi-constant. Here we prove that the character of the Hodge line bundle is always quasi-constant. Furthermore, we classify the quasi-constant characters of an arbitrary connected, reductive group over an arbitrary field. As an application, we observe that, if μ is a quasi-constant cocharacter of an F p -group G , then our construction of group-theoretical Hasse invariants in loc. cit. applies to the stack G - Zip μ , without any restrictions on p , even if the pair (G , μ) is not of Hodge type and even if μ is not minuscule. We conclude with a more speculative discussion of some further motivation for considering quasi-constant cocharacters in the setting of our program outlined in loc. cit. [ABSTRACT FROM AUTHOR]

For a sequence of continuous, monotone functions f1,…,fn:I→R (I is an interval) we define the mapping M:In→In as a Cartesian product of quasi-arithmetic means generated by fj-s. It is known that, for every initial vector, the iteration sequence of this mapping tends to the diagonal of In. We will prove that whenever all fj-s are C2 with nowhere vanishing first derivative, then this convergence is quadratic. Furthermore, the limit VarMk+1(v)(VarMk(v))2 will be calculated in a nondegenerated case. [ABSTRACT FROM AUTHOR]

In infinite-dimensional spaces, we investigate a set-valued system from the image perspective. By exploiting the quasi-interior and the quasi-relative interior, we give some new equivalent characterizations of (proper, regular) linear separation and establish some new sufficient and necessary conditions for the impossibility of the system under new assumptions, which do not require the set to have nonempty interior. We also present under mild assumptions the equivalence between (proper, regular) linear separation and saddle points of Lagrangian functions for the system. These results are applied to obtain some new saddle point sufficient and necessary optimality conditions of vector optimization problems. [ABSTRACT FROM AUTHOR]

We prove the existence of quasi-periodic small-amplitude solutions for quasi-linear Hamiltonian perturbation of the fifth order KdV equation on the torus in presence of a quasi-periodic forcing. [ABSTRACT FROM AUTHOR]

Complex energy eigenvalues which specify the location and width of quasibound or resonant states are computed to good approximation by a simple dimensional scaling method. As applied to bound states, the method involves minimizing an effective potential function in appropriately scaled coordinates to obtain exact energies in the D→∞ limit, then computing approximate results for D=3 by a perturbation expansion in 1/D about this limit. For resonant states, the same procedure is used, with the radial coordinate now allowed to be complex. Five examples are treated: the repulsive exponential potential (e-r); a squelched harmonic oscillator (r2e-r); the inverted Kratzer potential (r-1 repulsion plus r-2 attraction); the Lennard-Jones potential (r-12 repulsion, r-6 attraction); and quasibound states for the rotational spectrum of the hydrogen molecule (X 1∑g+, v=0, J=0 to 50). Comparisons with numerical integrations and other methods show that the much simpler dimensional scaling method, carried to second-order (terms in 1/D2), yields good results over an extremely wide range of the ratio of level widths to spacings. Other methods have not yet evaluated the very broad H2 rotational resonances reported here (J>=39), which lie far above the centrifugal barrier. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Pain is the property of Quintessence Publishing Company Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Programmatic research in sales is facilitated by the availability of scales with known and acceptable psychometric properties. Comer et al. (1989) have suggested a significantly shortened version of INDSALES for sales researchers who are constrained by questionnaire length. Using a quasi-replication methodology, we evaluate this shortened version of INDSALES by comparing the Comer et al. results with those of a non-industrial sample. Findings generally support the reduced scale's psychometric properties, although some qualifications are given. [ABSTRACT FROM AUTHOR]

The Borel map j ∞ takes germs at 0 of smooth functions to the sequence of iterated partial derivatives at 0. In the literature, it is well known that the restriction of j ∞ to the germs of quasianalytic ultradifferentiable classes which are strictly containing the real analytic functions can never be onto the corresponding sequence space. In this paper, we are interested in studying how large the image of j ∞ is and we investigate the size and the structure of this image by using different approaches (Baire residuality, prevalence and lineability). We give an answer to this question in the very general setting of quasianalytic ultradifferentiable classes defined by weight matrices, which contains as particular cases the classes defined by a single weight sequence or by a weight function. [ABSTRACT FROM AUTHOR]

In this paper, we prove that a class of quasi-periodically forced flow with external parameters on a m-torus is linearizable, i.e. conjugable to the quasi-periodic rotation, under some appropriate conditions. More concretely, utilizing Pöschel-Rüssmann KAM method we can find a quasi-periodic transformation such that this flow becomes a quasi-periodic linear flow in a Cantor subset of parameters when forcing frequency and unperturbed rotation vector to satisfy the Brjuno-Rüssmann’s non-resonant condition and a weaker non-degeneracy condition, respectively. While in the case where the unperturbed rotation vector does not satisfy the weaker non-degeneracy condition, Herman’s method is applied to overcome the degeneracy so that we show that some perturbed systems can conjugate to the original system with prescribed rotation vector Finally, as an application, our results are used to investigate the spectrum and eigenfunctions of a quasi-periodic Schrödinger operators. [ABSTRACT FROM AUTHOR]

In this paper, we consider the effective reducibility of the quasi-periodic linear Hamiltonian system x˙=A+εQt,εx, ε∈0,ε0, where A is a constant matrix with possible multiple eigenvalues and Q(t,ε) is analytic quasi-periodic with respect to t. Under nonresonant conditions, it is proved that this system can be reduced to y˙=A⁎ε+εR⁎t,εy, ε∈0,ε⁎, where R⁎ is exponentially small in ε, and the change of variables that perform such a reduction is also quasi-periodic with the same basic frequencies as Q. [ABSTRACT FROM AUTHOR]

In the present study, we introduce the classes QCV (μ; A;B) and QST (; A;B). Furthermore, we obtain coefficient bounds of these classes. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we characterize the centers of the quasi-homogeneous planar polynomial differential systems of any degree n ∈ N. First, we prove that the system does not admit centers if n is even, then present the sufficient and necessary conditions that the system admits a center if n is odd. Furthermore, we provide a simple method to obtain such these systems with center for a given order. [ABSTRACT FROM AUTHOR]

Abstract Over the last few years machine learning (ML) has evolved becoming pervasive in many scientific and industrial fields. Such success is ignited by the possibility of applying algorithms that can solve complex problems through generic rule formulations. With such premise, ML surely represents a new opportunity to improve existing design paradigms. In this paper we propose a novel ML-driven synthesis methodology that allows to describe generic Boolean functions through a representative subset of core expressions using Classification Trees (CTs). Obtained circuits are able to mimic Boolean functions to a certain degree of accuracy, hence the name quasi-exact logic functions. The proposed synthesis flow enables a smart hardware mapping of quasi-exact logic functions by means of reduced and ordered decision diagrams. Experiments conducted on a subset of open-source benchmarks demonstrate that CTs are indeed able to cover rather complex Boolean functions with a very high degree of accuracy, 88% on average, still requiring 3× less area over standard multi-level circuit counterparts. Highlights • A novel logic synthesis flow inspired by machine learning techniques is proposed. • Quasi-exact logic functions are obtained by training classification trees. • Binary Decision Diagrams are leveraged to perform trees minimization. [ABSTRACT FROM AUTHOR]

A galloping-based energy harvester, which is surrounded by structure(s) such as an enclosure, has an aerodynamic force change due to a change in flow caused by movement of the bluff body against the structure(s). Therefore, any model derived without considering this effect cannot predict the harvester's behavioral or energetic characteristics accurately. The main goal of this study was to develop a model that could be used to accurately simulate a galloping-based energy harvester surrounded by an enclosure. To consider the effect of the enclosure on the aerodynamic force applied to the bluff body, a bivariate quasi-static aerodynamic force model was newly proposed, which was accomplished by performing an experiment involving two variables, the attack angle, and the distance from the nearest wall of the bluff body. A set of governing nonlinear field equations reflecting this force model were derived, and their perturbed solutions were obtained and validated by comparison with experimental results. The effect of the enclosure on the performance of the present energy harvester system was investigated and discussed using both theoretical and experimental methods. [ABSTRACT FROM AUTHOR]

We employ a conformal mapping transformation to solve a generalized Grad-Shafranov equation with incompressible plasma flow of arbitrary direction and construct particular up-down asymmetric D-shaped and diverted tokamak equilibria. The proposed method can also be employed as an alternative quasi-analytic method to solving two dimensional elliptic partial differential equations. [ABSTRACT FROM AUTHOR]

In this work, we introduce implicit and explicit iterations for solving the variational inclusion problem for the sum of two operators and the fixed point problem of nonexpansive mappings. We then prove its strong convergence theorems in the framework of Banach spaces. We finally provide some applications of the main results. [ABSTRACT FROM AUTHOR]

In this paper, quasi-strict feasibility of a generalized mixed variational inequality as a new notation is introduced, which is weaker than its strict feasibility and recovers the existing concept of strict feasibility for a generalized variational inequality. By using the equivalent characterization of the nonemptiness and boundedness of the solution set for the generalized mixed variational inequality, it is proved that quasi-strict feasibility is a sufficient condition for the generalized mixed variational inequality with a f-pseudomonotone and upper hemicontinuous mapping to have a nonempty and bounded solution set in reflexive Banach spaces. Our results generalize and extend some known results in Zhong and Huang (J Optim Theory Appl 152(3):696-709, 2012). [ABSTRACT FROM AUTHOR]

We develop a convolution theory for quasianalytic ultradistributions of Gelfand–Shilov type. We also construct a special class of ultrapolynomials, and use it as a base for the parametrix method in the study of new topological and structural properties of several quasianalytic spaces of functions and ultradistributions. In particular, our results apply to Fourier hyperfunctions and Fourier ultra-hyperfunctions. [ABSTRACT FROM AUTHOR]

We show that the family of all holomorphic functions $f$ in a domain $D$ satisfying $$\begin{eqnarray}\frac{|f^{(k)}|}{1+|f|}(z)\leq C\quad \text{for all }z\in D\end{eqnarray}$$ (where $k$ is a natural number and $C>0$ ) is quasi-normal. Furthermore, we give a general counterexample to show that for $\unicode[STIX]{x1D6FC}>1$ and $k\geq 2$ the condition $$\begin{eqnarray}\frac{|f^{(k)}|}{1+|f|^{\unicode[STIX]{x1D6FC}}}(z)\leq C\quad \text{for all }z\in D\end{eqnarray}$$ does not imply quasi-normality. [ABSTRACT FROM AUTHOR]

Inspired by the Fibonacci tree shown in the recent book, Catalan Numbers, by Richard Stanley, we present a combinatorial way to construct double Riordan arrays by using ECO technique. The sequence characterizations of double Riordan arrays and subgroups of the double Riordan group are found. As an extension of Pascal–Fibonacci triangle, the compression forms of double Riordan arrays called double quasi-Riordan arrays are defined. The connections of lower triangular matrices and double Riordan arrays as well as their compressions are given. Those results are also extended to the case of high order Riordan arrays, which are defined in the paper. The pairs of Sheffer polynomials and pairs of summation formulas associated with double Riordan arrays are defined and discussed. [ABSTRACT FROM AUTHOR]

The ADR algebra R A of a finite-dimensional algebra A is a quasihereditary algebra. In this paper we study the Ringel dual R ( R A ) of R A . We prove that R ( R A ) can be identified with ( R A o p ) o p , under certain ‘minimal’ regularity conditions for A . In particular, over algebraically closed fields the Ringel dual of the ADR algebra R A is Morita equivalent to ( R A o p ) o p (with respect to a canonical labelling) if and only if all projective and injective A -modules are rigid and have the same Loewy length. We also give necessary and sufficient conditions for the ADR algebra to be Ringel selfdual. [ABSTRACT FROM AUTHOR]

Let f:A→B be a homomorphism of commutative rings and let J be an ideal of B. The amalgamation of A with B along J with respect to f is the subring of A×B given by A⋈fJ={(a,f(a)+j)∣a∈A,j∈J}. In this paper, we give some characterizations for the amalgamation construction to be a quasi-Frobenius ring. [ABSTRACT FROM AUTHOR]

In this report, we examine the structure of bimetallic nanomaterials prepared by an electrochemical approach known as hydride-terminated (HT) electrodeposition. It has been shown previously that this method can lead to deposition of a single Pt monolayer on bulk-phase Au surfaces. Specifically, under appropriate electrochemical conditions and using a solution containing PtCl42-, a monolayer of Pt atoms electrodeposits onto bulk-phase Au immediately followed by a monolayer of H atoms. The H atom capping layer prevents deposition of Pt multilayers. We applied this method to ~1.6 nm Au nanoparticles (AuNPs) immobilized on an inert electrode surface. In contrast to the well-defined, segregated Au/Pt structure of the bulk-phase surface, we observe that HT electrodeposition leads to the formation of AuPt quasi-random alloy NPs rather than the core@shell structure anticipated from earlier reports relating to deposition onto bulk phases. The results provide a good example of how the phase behavior of macro materials does not always translate to the nano world. A key component of this study was the structure determination of the AuPt NPs, which required a combination of electrochemical methods, electron microscopy, X-ray absorption spectroscopy, and theory (DFT and MD). [ABSTRACT FROM AUTHOR]

The geometric formulation of motion of the first-order linear homogenous scleronomous nonholonomic system subjected to active forces is studied with the nonholonomic mapping theory. The quasi-Newton law, the quasi-momentum theorem, and the second kind Lagrange equation of dynamical systems are obtained in the Riemann-Cartan configuration spaces. By the nonholonomic mapping, a Euclidean configuration space or a Riemann configuration space of a dynamical system can be mapped into a Riemann-Cartan configuration space with torsion. The differential equations of motion of the dynamical system can be obtained in its Riemann-Cartan configuration space by the quasi-Newton law or the quasi-momentum theorem. For a constrained system, the differential equations of motion in its Riemann-Cartan configuration space may be simpler than the equations in its Euclidean configuration space or its Riemann configuration space. Therefore, the nonholonomic mapping theory can solve some constrained problems, which are difficult to be solved by the traditional analytical mechanics method. Three examples are given to illustrate the effectiveness of the method. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new multi-edge metric-constrained quasi-cyclic progressive edge-growth algorithm (MM-QC-PEGA), which is suitable for constructing both single- and multi-weighted (binary) QC low-density parity-check (LDPC) codes with arbitrary lengths, rates, circulant sizes, and variable node (VN)-degree distributions. The MM-QC-PEGA is able to detect all cyclic-edge-set-minimum-virtual cycles (CMVCs), as it accurately computes the metric value of each CMVC with an a posteriori test. In addition, we propose a new greatest-common-divisor (GCD)-approximation for time efficiently approximating the metric value of a CMVC without a posteriori tests, and propose a new GCD-approximated MM-QC-PEGA (G-MM-QC-PEGA) by using the GCD-approximation to replace the a posteriori test involved in the MM-QC-PEGA. As a result, the G-MM-QC-PEGA is faster than the MM-QC-PEGA, and the CMVCs undetectable to the G-MM-QC-PEGA under multi- and single-weighted QC-LDPC code graphs have minimum lengths of eight and ten, respectively. Moreover, we propose a new masking technique that is efficient in masking the parity-check matrix consisting of an array of arbitrary circulants of the same size. Compared with the several existing works, our proposed algorithms could perform better or comparably in terms of avoiding generating small cycles and error performances. Our proposed algorithms somewhat perfect the works of QC-LDPC code construction. [ABSTRACT FROM PUBLISHER]

We consider quasi-geostrophic (QG) models in two- and three-layers that are useful in theoretical studies of planetary atmospheres and oceans. In these models, the streamfunctions are given by (1+2) partial differential systems of evolution equations. A two-layer QG model, in a simplified version, is dependent exclusively on the Rossby radius of deformation. However, the f-plane QG point vortex model contains factors such as the density, thickness of each layer, the Coriolis parameter, and the constant of gravitational acceleration, and this two-layered model admits a lesser number of Lie point symmetries, as compared to the simplified model. Finally, we study a three-layer oceanography QG model of special interest, which includes asymmetric wind curl forcing or Ekman pumping, that drives double-gyre ocean circulation. In three-layers, we obtain solutions pertaining to the wind-driven doublegyre ocean flow for a range of physically relevant features, such as lateral friction and the analogue parameters of the f-plane QG model. Zero-order invariants are used to reduce the partial differential systems to ordinary differential systems. We determine conservation laws for these QG systems via multiplier methods. [ABSTRACT FROM AUTHOR]

We introduce the notion of degree of imperfection of a code in Zn with the ℓp metric, to extend the so-called quasi-perfect codes. Through the establishment of bounds and computational approach, we determine all radii for which there are linear quasi-perfect codes for p=2 and n=2,3. Numerical results concerning the codes with small degree of imperfection are also presented. [ABSTRACT FROM AUTHOR]

Working in the framework of Borel reducibility, we study various notions of embeddability between groups. We prove that the embeddability between countable groups, the topological embeddability between (discrete) Polish groups, and the isometric embeddability between separable groups with a bounded bi-invariant complete metric are all invariantly universal analytic quasi-orders. This strengthens some results from works by Williams and Ferenczi, Louveau and Rosendal. [ABSTRACT FROM AUTHOR]