bluuebunny/crossref_metadata_2025 huggingface dataset:
Lp regularity of velocity averages
Authors: Diperna R.J. , Lions P.L. , Meyer Y.
Published: February 2017

In this article, we present some general regularity results for “velocity averages”
i. e.
averages in

ν

of functions

f(x, v)

for which

(v.∇_x f)

has some given regularity. We are able to cover general regularity classes for both

f

and

(v.∇_x f)

and we thus extend various known results. Our methods of proof rely on Littlewood–Paley type decompositions, interpolation arguments and a spectral decomposition adapted to the “velocity direction”.

Nous présentons dans cet article des résultats généraux de régularité de moyennes en vitesse (c’est-à-dire de moyennes en

ν

) de fonctions

f(x, v)

pour lesquelles

(v.∇_x f)

a une certaine régularité. Nos résultats permettent des classes de régularité générales pour

f

et

(v.∇_x f)

, généralisant ainsi plusieurs résultats antérieurs. Notre méthode de preuve repose sur les décompositions de type Littlewood–Paley, des arguments d’interpolation et une décomposition spectrale adaptée à la « direction des vitesses ».
On the modified Enskog equation for elastic and inelastic collisions. Models with spin
Authors: Perthame Benoît , Esteban Maria J.
Published: February 2017

Under appropriate assumptions on the collision kernel we prove the existence of global solutions of the Enskog equation with elastic or inelastic collisions. We consider also this equation with spin, that is, the case when the angular velocities of the colliding particles are taken into account. In this case we also prove global existence results.

Nous démontrons que sous des hypothèses appropriées sur le noyau de collision il existe une solution globale de l’équation d’Enskog avec collisions élastiques ou inélastiques. Nous considérons aussi le modèle avec spin, où la vitesse angulaire des particules n’est pas négligée dans la description des collisions. Dans ce cas nous prouvons aussi des résultats d’existence de solutions globales en temps.
On the static and dynamic study of oscillations for some nonlinear hyperbolic systems of conservation laws
Authors: Rascle Michel
Published: February 2017

We first show that no oscillation can
appear
in a 2 × 2 hyperbolic system whose two eigenvalues are linearly degenerate. For such a system, oscillations can only propagate. The method uses both compensated compactness ideas and the characteristics of the system, which is partly formal. We then make some heuristic remarks on the extension to the 3 × 3 gas dynamics system, and we link this question to the “separation of the wave cone and the constitutive manifold” (Ron DiPerna).

On montre d’abord qu’aucune oscillation ne peut
apparaître
dans un système 2 × 2 dont les deux valeurs propres sont linéairement dégénérées. pour un tel système, les oscillations peuvent seulement se propager. La méthode utilise à la fois des idées de compacité par compensation et les caractéristiques du système, ce qui est partiellement formel. On fait ensuite quelques remarques heuristiques sur le système 3 × 3 de la dynamique des gaz, et on relie cette question à la « séparation du cône d’ondes et de la variété constitutive » (Ron DiPerna).
Oscillations non linéaires des systèmes hyperboliques: méthodes et résultats qualitatifs
Authors: Serre Denis
Published: February 2017

One studies the Cauchy problem for hyperbolic systems of first order conservation laws

∂_tu + ∂_xf(u) = 0

, with an oscillating sequence of initial data. The oscillations have an

O(1)

amplitude; one may think to

u^{\mathrm{\varepsilon }}(x,0) = a(x;\frac{x}{\mathrm{\varepsilon }})

, where

a(x,.)

is periodic.

It turns out that one part of the initial oscillations are killed because of genuine non-linearity. But the most of the physically relevant systems are endowed with at least one linearly degenerate characteristic field, which allows oscillations of a part of the field

u

.

Our goal is to describe these oscillations and their propagation. There are several steps:

Of particular interest is the computation of the group speeds, which are nothing but the characteristic values of the relaxed system. Formulas are given, especially for the full gas dynamics, which are all but trivial.

The description of oscillations has been asked by Ronald DiPerna in 1985, who introduced the similar concept of “measure-valued solutions”. An equivalent problem is to determine whether the set of solutions is closed or not in the weak-star topology of

L^∞

. Thus this work is an attempt to understand well-posedness (or illposedness, the both occur depending on the system) in

L^∞

, one of the two classes where a ferv existence results are known.

This study has also implications for numerical analysis. It suggests multi-scale methods which would give accurate values of speed when mild oscillations occur.

The paper is organized into three parts. Section II-V are devoted to a rigourous analysis with applications. Sections VI-VIII concerns speculative (but efficient) ideas; this heuristic procedure gives the first description of the oscillations in gas dynamics and elastic string. The end of the article is concerned with a conjecture I made in 1983 about the compensated compactness method.

On considère les oscillations de grande amplitude des systèmes hyperboliques de lois de conservation. Les champs vraiment non linéaires en tuent une partie tandis que les champs linéairement dégénérés en laissent une autre part se propager selon des vitesses de groupe obéissant à des formules compliquées. Cet article rassemble des résultats rigoureux via la compacité par compensation et des calculs heuristiques.
Maximum principles and a priori estimates for a class of problems from nonlinear elasticity
Authors: Bauman Patricia , Owen Nicholas C. , Phillips Daniel
Published: February 2017

We consider smooth solutions,

\mathscr U

, to the nonlinear elliptic system associated with a two dimensional elastic material which has energy functional

\mathscr W(\mathscr U)=\int_\Omega \Big( \frac{|D\mathscr U|^2}2 + H(\operatorname{det} D\mathscr U)\Big) dX

The function

H(d)

is nonnegative, convex and unbounded in a neighborhood of zero. Two maximum principles are proved for

D\mathscr U

and we show that if

Ω'\Subset Ω

then

\Vert D\mathscr U \Vert_{C^\alpha(\Omega')}

and

\Vert D\mathscr U^{-1} \Vert_{L^\infty(\Omega')}

are bounded
a priori
in terms of

\Vert D\mathscr U \Vert_{L^p(\Omega')}

and

\mathscr W(\mathscr U)

for some

p = p(H)

.

On considère une solution régulière

\mathscr U

du système elliptique non linéaire associé à la fonctionnelle d’énergie

\mathscr W(\mathscr U)=\int_\Omega \Big( \frac{|D\mathscr U|^2}2 + H(\operatorname{det} D\mathscr U)\Big) dX

en dimension 2, la fonction

H

étant positive, convexe, et

H(t) → + ∞

quand

t → 0_+

. On démontre deux principes du maximum et une estimation de

D\mathscr U

à l’intérieur de

Ω

.
On the existence of solutions to a problem in multidimensional segmentation
Authors: Congedo G. , Tamanini I.
Published: February 2017

We prove the existence of a minimizer for a multidimensional variational problem related to the Mumford-Shah approach to computer vision.

On démontre l’existence d’un minimum pour un problème variationnel en dimension

n

, voisin de celui que Mumford et Shah ont postulé à la base de la vision artificielle.
Exposant critique de Sobolev et régularité des solutions d’équations elliptiques
Authors: Benmohamed A. , Robbiano L.
Published: February 2017

We study the regularity of solutions to elliptic problems. The coefficients of the term of order one [resp. zero] are in

L^n

[resp.

L^{n/2}

]. This allows us to deduce the regularity of solutions to some non linear elliptic problems with Sobolev critical exponent.

Nous étudions la régularité des solutions de problèmes elliptiques avec des termes d’ordre un [resp. zéro] à coefficients dans

L^n(\mathbb R^n

) [resp.

L^{n/2}(\mathbb R^n

)]. Cela permet de déduire la régularité des solutions de certains problèmes elliptiques non linéaires avec exposant critique de Sobolev.
Sur une équation quasilinéaire d’ordre 2 non elliptique
Authors: Aubert G.
Published: February 2017

We prove, for small data, the existence of a regular solution for the quasilinear problem:

−\mathrm{div}\left(\mathrm{D}g\left(\mathrm{D}u\right)\right) + \mathrm{F}\left(x,u\right) = 0,\:u \in \mathrm{W}_{0}^{1,p}\left(\mathrm{\Omega }\right).

We do not assume any condition of ellipticity on

g

; only we suppose that

g

is the difference of two stricly convex functions.

On prouve l’existence, pour des données petites, d’une solution régulière pour le problème quasilinéaire :

−\mathrm{div}\left(\mathrm{D}g\left(\mathrm{D}u\right)\right) + \mathrm{F}\left(x,u\right) = 0,\:u \in \mathrm{W}_{0}^{1,p}\left(\mathrm{\Omega }\right).

On ne fait aucune hypothèse d’ellipticité sur

g

; nous supposons simplement que

g

est la différence de deux fonctions strictement convexes.
On a superlinear elliptic equation
Authors: Wang Zhi Qiang
Published: February 2017

In this note we establish multiple solutions for a semilinear elliptic equation with superlinear nonlinearility without assuming any symmetry.

Dans cet article, nous montrons l’existence de plusieurs solutions pour une équation semi-linéaire elliptique avec une condition de non-linéarité superlinéaire, sans hypothèse de symmétric
On the existence of multiple geodesics in static space-times
Authors: Fortunato D. , Giannoni F. , Benci V.
Published: February 2017

In this paper we study the problem of the existence of geodesies in static space-times which are a particular case of Lorentz manifolds. We prove multiplicity results about geodesies joining two given events and about periodic trajectories having a prescribed period.

Dans ce papier on étudie le problème de l’existence de géodésiques dans les espaces-temps statiques qui représentent un cas particulier de variétés de Lorentz. On démontre ici des résultats de multiplicité pour les géodésiques qui relient deux events fixés et pour les trajectoires périodiques ayant une période fixée.
Propriétés des matrices « bien localisées » près de leur diagonale et quelques applications
Authors: Jaffard S.
Published: February 2017

In the following paper, two classes of infinite matrices are studied (matrices with exponentially or polynomially decreasing coefficients away from the diagonal). Properties of symbolic calculus type are shown: Inversibility on

l^2

implies that the inverse has the same decay property. It is also shown that inversion is a “local” transformation of the matrix: A change in the coefficients is not felt far away from the area changed. Two applications concerning the properties of orthonormal bases of wavelets are given.

Nous étudions dans cet article deux classes de matrices infinies (matrices dont les coefficients sont à décroissance exponentielle ou polynomiale en s’éloignant de la diagonale). Nous montrons qu’elles possèdent des propriétés du type « calcul symbolique » : L’inversibilité sur

l^2

implique que les coefficients de la matrice inverse ont la même propriété de décroissance. De plus, l’inversion est une opération « locale » : Une perturbation des coefficients de A n’est pas ressentie sur son inverse loin de la zone de perturbation. Nous fournissons deux exemples d’applications concernant les propriétés des bases orthonormées d’ondelettes.
Periodic solutions for N-body type problems
Authors: Coti Zelati Vittorio
Published: February 2017

In this paper we prove the existence of a

T

-periodic solution (for any given

T

) for a class of Hamiltonian systems which includes the

N

-body one. We also prove that the solution we find is not a simultaneous collision one.

Dans l’article on démontre l’existence d’une solution

T

-périodique (pour chaque

T > 0

) pour un ensemble de systèmes hamiltoniens comprenant celui des

N

-corps. On démontre aussi que la solution ainsi trouvée n’est pas une solution de collision totale.
An eigenvalue problem for the complex Monge–Ampère operator in pseudoconvex domains
Authors: Kutev N.D. , Ramadanov I.P.
Published: February 2017

A problem of existence and unicity of eigenvalues and corresponding eigenfunctions concerning the complex Monge–Ampère operator

\operatorname{det}\left(\mathrm{∂}^{2}u/ \mathrm{∂}z_{j}\mathrm{∂}\bar z_{k}\right)

and right-hand side of the forme

F(z, u)

is studied in a bounded strictly pseudoconvex domain of

\mathbb C^n

.

Un problème d’existence et d’unicité de valeurs propres et de fonctions correspondantes concernant l’opérateur de Monge–Ampère complexe

\operatorname{det}\left(\mathrm{∂}^{2}u/ \mathrm{∂}z_{j}\mathrm{∂}\bar z_{k}\right)

à second membre de la forme

F(z, u)

est étudié dans un domaine borné strictement pseudoconvexe de

\mathbb C^n

.
An approach of deterministic control problems with unbounded data
Authors: Barles G.
Published: February 2017

We prove that the value function of a deterministic unbounded control problem is a viscosity solution and the maximum viscosity subsolution of a family of Bellman Equations; in particular, the one given by the hamiltonian, generally discontinuous, associated formally to the problem by analogy with the bounded case. In some cases, we show that this equation is equivalent to a first-order Hamilton–Jacobi Equation with gradient constraints for which we give several existence and uniqueness results. Finally, we indicate other applications of these results to first-order H. J. Equations, to some cheap control problems and to uniqueness results in the nonconvex Calculus of Variations.

Nous prouvons que la fonction valeur d’un problème de contrôle déterministe non borné est une solution de viscosité et la soussolution de viscosité maximale d’une famille d’équations de Bellman; en particulier, celle donnée par l’hamiltonien, généralement discontinu, associé formellement au problème par analogie avec le cas borné. Dans certains cas, nous montrons que cette équation est équivalente à une équation de Hamilton–Jacobi du premier ordre avec contraintes sur le gradient pour laquelle nous donnons des résultats d’existence et d’unicité variés. Enfin, nous indiquons d’autres applications de ces résultats à des équations de H. J. du premier ordre, à certains problèmes de contrôle impulsionnel ainsi qu’à des résultats d’unicité dans des problèmes non convexes du Calcul des Variations.
The stability of one dimensional stationary flows of compressible viscous fluids
Authors: Beirão da Veiga H.
Published: February 2017

In [1], § 5 we gave a necessary and sufficient condition for the existence of stationary solutions for the system (1.1) in the presence of arbitrarily large external forces

f(x)

. Here we prove, see theorem 2.1, that every stationary solution is necessarily stable. We use Euler coordinates, since a proof in Lagrange coordinates (see for instance [2], [3], [4]) should present greater obstacles.

On démontre que toute solution du système d’équations décrivant le mouvement unidimensionnel d’un fluide compressible et visqueux (avec des forces arbitraires et indépendantes du temps) est nécessairement stable.
Nonuniqueness for the heat flow of harmonic maps
Authors: Coron J.-M.
Published: February 2017

We construct maps

u_0 : B^3 → S^2

such that the Cauchy problem « find

u : B^3 × [0, + ∞) → S^2

such that

u(x, 0) = u_0(x)

in

B^3

,

u_{t}−\mathrm{\Delta }u = u\:\left|\nabla u\right|^{2}

,

u = u_0

on

∂B^3 × [0, + ∞)

» has infinitely many weak solutions.

On construit des applications

u_0

de

B^3

dans

S^2

telles que le problème de Cauchy « trouver

u : B^3 × [0, + ∞ [→ S^2

tel que

u_{t}−\mathrm{\Delta }u = u\:\left|\nabla u\right|^{2}

,

u(x, 0) = u_0(x)

dans

B^3

,

u = u_0

sur

∂\mathrm{B}^{3} \times [0,\: + \infty [

» a une infinité de solutions faibles.
Biting theorems for Jacobians and their applications
Authors: Zhang K.
Published: February 2017

Weak continuity for sequences of Jacobians of vector-valued functions in

W^{1,n}(Ω; R^n)

in the sense of Chacon’s Biting Lemma [13] is established via a maximal function method developed by Acerbi and Fusco [1]. A « div-curl » Lemma in the same spirit is also proved. The results are applied to the existence problem of nonlinear elastostatics and to a problem involving rank-one connections appearing in the theory of phase transitions.

On démontre un théorème de continuité faible, au sens du lemme de morsure de Chacon, pour des suites de jacobiens de fonctions dans

W^{1,n}(Ω; R^n)

, ainsi qu’un lemme « div-rot ». Pour ce faire, on utilise la méthode de fonction maximale introduite par Acerbi et Fusco.
A generalization of a theorem of H. Brezis & F. E. Browder and applications to some unilateral problems
Authors: Boccardo L. , Giachetti D. , Murat F.
Published: February 2017

The first Section of this paper is devoted to prove the following Theorem, which extends previous results of H. Brezis and F. E. Browder: Let

w \in \:\mathrm{W}_{0}^{m,p}(\mathrm{\Omega })

,

w ≥ 0

a. e. in

\mathrm Ω

and

T \in W^{−m,p'}(\mathrm Ω)

,

T = μ + h

where

μ

is a positive Radon measure and

h \in \mathrm{L}_{\mathrm{loc}}^{1}(\mathrm{\Omega })

is such that

hw ≥ − |Φ|

a. e. in

\mathrm Ω

for some

Φ ϵ L^1(\mathrm Ω)

; then

w

belongs to

L^1(\mathrm Ω; dμ)

,

hw

belongs to

L^1(\mathrm Ω)

and

〈\mathrm{T},\:\:w〉 = \int _{\mathrm{\Omega }}wd\mu + \:\int _{\mathrm{\Omega }}\:hwdx

.

The second and third Sections deal with applications of this Theorem to the study of two unilateral problems.

Sunto

Nella prima parte di quest’articolo viene dimostrato il seguente teorema che costituisce una generalizzazione di risultati ottenuti da H. Brezis e F. E. Browder : Sia

w \in \:\mathrm{W}_{0}^{m,p}(\mathrm{\Omega })

,

w ≥ 0

q. 0. in

\mathrm Ω

e

T \in W^{−m,p'}(\mathrm Ω)

,

T = μ + h

dove

μ

è una misura positiva di Radon e

h \in \mathrm{L}_{\mathrm{loc}}^{1}(\mathrm{\Omega })

è tale che

hw ≥ − |Φ|

q. o. in

\mathrm Ω

per un certo

Φ ϵ L^1(\mathrm Ω)

; allora

w

appartiene a

\mathrm{L}^{1}(\mathrm{\Omega };\:d\mu )

,

hw

a

\mathrm{L}^{1}(\mathrm{\Omega })

e

〈\mathrm{T},\:w〉=\int _{\mathrm{\Omega }}wd\mu + \int _{\mathrm{\Omega }}hwdx

.

Nella seconda e terza parte tale risultato viene applicato allo studio di due problemi unilaterali.

Dans la première partie de cet article on démontre le théorème suivant, qui généralise des résultats de H. Brezis et F. E. Browder : Soient

w \in \:\mathrm{W}_{0}^{m,p}(\mathrm{\Omega })

,

w ≥ 0

p. p. dans

\mathrm Ω

et

T \in W^{−m,p'}(\mathrm Ω)

,

T = μ + h

où

μ

est une mesure de Radon positive et où

h \in \mathrm{L}_{\mathrm{loc}}^{1}(\mathrm{\Omega })

est telle que

hw ≥ − |Φ|

p. p. dans

\mathrm Ω

pour un certain

Φ \in L^1(\mathrm Ω)

; alors

w

appartient à

L^1(Ω; dμ)

,

hw

appartient à

\mathrm{L}^{1}(\mathrm{\Omega })

et

〈\mathrm{T},\:\:w〉= \int _{\mathrm{\Omega }}wd\mu + \int _{\mathrm{\Omega }}hwdx

.

Dans la deuxième et la troisième parties on applique ce théorème à l’étude de deux problèmes unilatéraux.
La théorie mathématique de l’équilibre économique: extension du modèle de Arrow-Debreu au cadre non convexe
Authors: Cornet Bernard
Published: February 2017

The aim of this paper is to present the mathematical theory of economic equibrium in the classical model developed by K. Arrow and G. Debreu, together with one of its recent generalizations which aim to take into account the presence of “nonconvexities” in the production sector.

This generalization is important from the economic point of view since the convexity of production sets, the assumption made by Arrow and Debreu, seems to be more the exception than the rule; in particular, the presence of increasing returns (a particular form of nonconvexities) in production sectors such as railways or electricity production is recognized since the past century.

The mathematical treatment of “nonconvexities” requires techniques more sophisticated than the ones used in the classical theory; firstly, tools from “Non-smooth Analysis” developed during the past ten years and secondly, tools from global analysis.

Le but de cet article est de présenter la théorie mathématique de l’équilibre économique dans le cadre classique traité par K. Arrow et G. Debreu, ainsi qu’une de ses généralisations récentes qui prend en compte les « non-convexités » dans le secteur de la production.

Cette généralisation est importante sur le plan économique car la convexité des ensembles de production, hypothèse faite par Arrow-Debreu, semble être l’exception plutôt que la règle; en particulier, la présence de rendements croissants (une forme particulière de non-convexité) dans des secteurs de production comme l’électricité ou les chemins de fer est reconnue depuis le siècle dernier.

Sur le plan mathématique, la généralisation au cadre non convexe nécessite l’utilisation de techniques plus sophistiquées que dans la théorie classique; d’une part, des outils d’« analyse non différentiable » développés durant les dix dernières années et, d’autre part, des outils de topologie différentielle et de la théorie de Morse.
Existence of a closed geodesic on p-convex sets
Authors: Canino Annamaria
Published: February 2017

The existence of a non constant closed geodesie on some nonsmooth sets is proved.

On montre l’existence d’une géodésique fermée non constante sur certains ensembles non réguliers.
Faulty Foundings and Failed Reformers in Machiavelli'sFlorentine Histories
Authors: MCCORMICK JOHN P.
Published: February 2017

T his article argues against prevailing scholarly trends that theFlorentine Historiescontinues to delineate the ways through which Niccolò Machiavelli, inThe Princeand theDiscourses, advised potential founders or reformers to exploit, for their own benefit and that of their patria, the inevitable social conflicts between elites and the people that arise in all polities. Machiavelli demonstrates that, in particular, Giano della Bella and Michele di Lando could and should have attempted to imitate exemplary ancient founders and reformers whom he praises in previous works, especially Moses, Romulus, and Brutus. Machiavelli implicitly criticizes Giano and Michele for failing to spiritedly invigorate new laws with necessary and salutary violence; for neglecting to effectively manage the “envy” of rival peers; for not resisting the allure of “middle ways” between difficult political choices; and for failing to militarily organize or mobilize the entirety of Florence's common people.
Breather soliton dynamics in microresonators
Authors: Yu Mengjie , Jang Jae K. , Okawachi Yoshitomo , Griffith Austin G. , Luke Kevin , Miller Steven A. , Ji Xingchen , Lipson Michal , Gaeta Alexander L.
Published: February 2017

The generation of temporal cavity solitons in microresonators results in coherent low-noise optical frequency combs that are critical for applications in spectroscopy, astronomy, navigation or telecommunications. Breather solitons also form an important part of many different classes of nonlinear wave systems, manifesting themselves as a localized temporal structure that exhibits oscillatory behaviour. To date, the dynamics of breather solitons in microresonators remains largely unexplored, and its experimental characterization is challenging. Here we demonstrate the excitation of breather solitons in two different microresonator platforms based on silicon nitride and on silicon. We investigate the dependence of the breathing frequency on pump detuning and observe the transition from period-1 to period-2 oscillation. Our study constitutes a significant contribution to understanding the soliton dynamics within the larger context of nonlinear science.
Dynamic plasmonic colour display
Authors: Duan Xiaoyang , Kamin Simon , Liu Na
Published: February 2017

Plasmonic colour printing based on engineered metasurfaces has revolutionized colour display science due to its unprecedented subwavelength resolution and high-density optical data storage. However, advanced plasmonic displays with novel functionalities including dynamic multicolour printing, animations, and highly secure encryption have remained in their infancy. Here we demonstrate a dynamic plasmonic colour display technique that enables all the aforementioned functionalities using catalytic magnesium metasurfaces. Controlled hydrogenation and dehydrogenation of the constituent magnesium nanoparticles, which serve as dynamic pixels, allow for plasmonic colour printing, tuning, erasing and restoration of colour. Different dynamic pixels feature distinct colour transformation kinetics, enabling plasmonic animations. Through smart material processing, information encoded on selected pixels, which are indiscernible to both optical and scanning electron microscopies, can only be read out using hydrogen as a decoding key, suggesting a new generation of information encryption and anti-counterfeiting applications.
Deliberate and Accidental Gas-Phase Alkali Doping of Chalcogenide Semiconductors: Cu(In,Ga)Se2
Authors: Colombara Diego , Berner Ulrich , Ciccioli Andrea , Malaquias João C. , Bertram Tobias , Crossay Alexandre , Schöneich Michael , Meadows Helene J. , Regesch David , Delsante Simona , Gigli Guido , Valle Nathalie , Guillot Jérome , El Adib Brahime , Grysan Patrick , Dale Phillip J.
Published: February 2017

Alkali metal doping is essential to achieve highly efficient energy conversion in Cu(In,Ga)Se2 (CIGSe) solar cells. Doping is normally achieved through solid state reactions, but recent observations of gas-phase alkali transport in the kesterite sulfide (Cu2ZnSnS4) system (re)open the way to a novel gas-phase doping strategy. However, the current understanding of gas-phase alkali transport is very limited. This work (i) shows that CIGSe device efficiency can be improved from 2% to 8% by gas-phase sodium incorporation alone, (ii) identifies the most likely routes for gas-phase alkali transport based on mass spectrometric studies, (iii) provides thermochemical computations to rationalize the observations and (iv) critically discusses the subject literature with the aim to better understand the chemical basis of the phenomenon. These results suggest that accidental alkali metal doping occurs all the time, that a controlled vapor pressure of alkali metal could be applied during growth to dope the semiconductor, and that it may have to be accounted for during the currently used solid state doping routes. It is concluded that alkali gas-phase transport occurs through a plurality of routes and cannot be attributed to one single source.
Bottom-trawling along submarine canyons impacts deep sedimentary regimes
Authors: Paradis Sarah , Puig Pere , Masqué Pere , Juan-Díaz Xènia , Martín Jacobo , Palanques Albert
Published: February 2017

Many studies highlight that fish trawling activities cause seafloor erosion, but the assessment of the remobilization of surface sediments and its relocation is still not well documented. These impacts were examined along the flanks and axes of three headless submarine canyons incised on the Barcelona continental margin, where trawling fleets have been operating for decades. Trawled grounds along canyon flanks presented eroded and highly reworked surface sediments resulting from the passage of heavy trawling gear. Sedimentation rates on the upper canyon axes tripled and quadrupled its natural (i.e. pre-industrialization) values after a substantial increase in total horsepower of the operating trawling fleets between 1960 s and 1970 s. These impacts affected the upper canyon reaches next to fishing grounds, where sediment resuspended by trawling can be transported towards the canyon axes. This study highlights that bottom trawling has the capacity to alter natural sedimentary environments by promoting sediment-starved canyon flanks, and by enhancing sedimentation rates along the contiguous axes, independently of canyons’ morphology. Considering the global mechanisation and offshore expansion of bottom trawling fisheries since the mid-20th century, these sedimentary alterations may occur in many trawled canyons worldwide, with further ecological impacts on the trophic status of these non-resilient benthic communities.
3-D phononic crystals with ultra-wide band gaps
Authors: Lu Yan , Yang Yang , Guest James K. , Srivastava Ankit
Published: February 2017

In this paper gradient based topology optimization (TO) is used to discover 3-D phononic structures that exhibit ultra-wide normalized all-angle all-mode band gaps. The challenging computational task of repeated 3-D phononic band-structure evaluations is accomplished by a combination of a fast mixed variational eigenvalue solver and distributed Graphic Processing Unit (GPU) parallel computations. The TO algorithm utilizes the material distribution-based approach and a gradient-based optimizer. The design sensitivity for the mixed variational eigenvalue problem is derived using the adjoint method and is implemented through highly efficient vectorization techniques. We present optimized results for two-material simple cubic (SC), body centered cubic (BCC), and face centered cubic (FCC) crystal structures and show that in each of these cases different initial designs converge to single inclusion network topologies within their corresponding primitive cells. The optimized results show that large phononic stop bands for bulk wave propagation can be achieved at lower than close packed spherical configurations leading to lighter unit cells. For tungsten carbide - epoxy crystals we identify all angle all mode normalized stop bands exceeding 100%, which is larger than what is possible with only spherical inclusions.
Evolutionary, computational, and biochemical studies of the salicylaldehyde dehydrogenases in the naphthalene degradation pathway
Authors: Jia Baolei , Jia Xiaomeng , Hyun Kim Kyung , Ji Pu Zhong , Kang Myung-Suk , Ok Jeon Che
Published: February 2017

Salicylaldehyde (SAL) dehydrogenase (SALD) is responsible for the oxidation of SAL to salicylate using nicotinamide adenine dinucleotide (NAD+) as a cofactor in the naphthalene degradation pathway. We report the use of a protein sequence similarity network to make functional inferences about SALDs. Network and phylogenetic analyses indicated that SALDs and the homologues are present in bacteria and fungi. The key residues in SALDs were analyzed by evolutionary methods and a molecular simulation analysis. The results showed that the catalytic residue is most highly conserved, followed by the residues binding NAD+ and then the residues binding SAL. A molecular simulation analysis demonstrated the binding energies of the amino acids to NAD+ and/or SAL and showed that a conformational change is induced by binding. A SALD from Alteromonas naphthalenivorans (SALDan) that undergoes trimeric oligomerization was characterized enzymatically. The results showed that SALDan could catalyze the oxidation of a variety of aromatic aldehydes. Site-directed mutagenesis of selected residues binding NAD+ and/or SAL affected the enzyme’s catalytic efficiency, but did not eliminate catalysis. Finally, the relationships among the evolution, catalytic mechanism, and functions of SALD are discussed. Taken together, this study provides an expanded understanding of the evolution, functions, and catalytic mechanism of SALD.
Construction of Au–Pd alloy shells for enhanced catalytic performance toward alkyne semihydrogenation reactions
Authors: Li Xiang , Wang Zhenni , Zhang Zhaorui , Yang Guang , Jin Mingshang , Chen Qiang , Yin Yadong
Published: February 2017

Au–Pd alloy surfaces have been fabricated on preformed Pd nanocrystals for highly active and selective alkyne semihydrogenation reactions.
Dual-encapsulation of octadecanol in thermal/electric conductor for enhanced thermoconductivity and efficient energy storage
Authors: Wu Wenhao , Yao Ruimin , Huang Xinyu , Chen Renjie , Li Kai , Gao Song , Zou Ruqiang
Published: February 2017

A novel, thermally and electrically conductive phase change composite was fabricated for enhanced thermoconductivity and high-efficiency energy storageviaa dual-encapsulation method using graphite foam as the skeleton and waterborne polyurethane as a sealing film.
Dynamical regime of resorcinol based Belousov–Zhabotinsky chemical oscillator in the presence or absence of some hydrophobic antioxidants in aqueous–organic mixed media
Authors: Ganaie Nadeem Bashir , Peerzada Ghulam Mustafa
Published: February 2017

BZ reaction acts as radical generator in AN/DMF mixed solvent system.
Controlled synthesis of perovskite lanthanum ferrite nanotubes with excellent electrochemical properties
Authors: Li Zijiong , Zhang Weiyang , Yuan Chaosheng , Su Yuling
Published: February 2017

In this work, we have fabricated a series of perovskite-type oxide LaFeO3 samples using a simple sol–gel method and further calcination treatment.
A self-powered solar-blind ultraviolet photodetector based on a Ag/ZnMgO/ZnO structure with fast response speed
Authors: Fan Ming-Ming , Liu Ke-Wei , Chen Xing , Zhang Zhen-Zhong , Li Bing-Hui , Shen De-Zhen
Published: February 2017

Realization of Ag/ZnMgO/ZnO photodetectors provides a feasible route to develop self-powered solar-blind UV photodetectors with fast response speed.
Microstructure, morphology and electrochemical properties of Co nanoflake water oxidation electrocatalyst at micro- and nanoscale
Authors: Naseri Naimeh , Solaymani Shahram , Ghaderi Atefeh , Bramowicz Miroslaw , Kulesza Slawomir , Ţălu Ştefan , Pourreza Mohammad , Ghasemi Shahnaz
Published: February 2017

Nowadays, fossil fuel limitations and environmental concerns push researchers to find clean and renewable energy resources.
SnSb electrodes for Li-ion batteries: the electrochemical mechanism and capacity fading origins elucidated by using operando techniques
Authors: Antitomaso Philippe , Fraisse Bernard , Stievano Lorenzo , Biscaglia Stéphane , Aymé-Perrot David , Girard Philippe , Sougrati Moulay T. , Monconduit Laure
Published: February 2017

Operando XRD and Mössbauer spectroscopy to elucidate the mechanism of the SnSb/Li battery.
Photosensitizer loaded PEG-MoS2–Au hybrids for CT/NIRF imaging-guided stepwise photothermal and photodynamic therapy
Authors: Liu Li , Wang Jinping , Tan Xiaoxiao , Pang Xiaojuan , You Qing , Sun Qi , Tan Fengping , Li Nan
Published: February 2017

We develop X-ray computed tomography/near-infrared fluorescence imaging for visually guiding the photothermal/photodynamic therapy of antitumor nanocomposites (PEG-MoS2–Au–Ce6), by adsorbing chlorin e6 to the gold nanoparticle-decorated molybdenum disulfide nanosheets.
An efficient rare-earth free deep red emitting phosphor for improving the color rendering of white light-emitting diodes
Authors: Liang Sisi , Shang Mengmeng , Lian Hongzhou , Li Kai , Zhang Yang , Lin Jun
Published: February 2017

The Mn4+doped Mg14Ge5O24phosphor produces deep red emission, and the structure, photoluminescence properties, thermal stability and the performance of fabricated WLED are all investigated.
The first palladium(iv) aryldiazenido complex: relevance for C–C coupling
Authors: Daryanavard Marzieh , Armstrong David , Lough Alan J. , Fekl Ulrich
Published: February 2017

The first observed and characterized palladium(iv) aryldiazenido complex.
History of EPI Suite™ and future perspectives on chemical property estimation in US Toxic Substances Control Act new chemical risk assessments
Authors: Card Marcella L. , Gomez-Alvarez Vicente , Lee Wen-Hsiung , Lynch David G. , Orentas Nerija S. , Lee Mari Titcombe , Wong Edmund M. , Boethling Robert S.
Published: February 2017

A discussion of the past developments, current practices, and future opportunities in QSAR modeling for new chemical risk assessments.
Solid-state-processing of δ-PVDF
Authors: Martín Jaime , Zhao Dong , Lenz Thomas , Katsouras Ilias , de Leeuw Dago M. , Stingelin Natalie
Published: February 2017

Solid-state pressing is used to produce, in one single-step and without the need to mechanically stretch thin foils, ferroelectric structures from the commodity polymer poly(vinylidene fluoride) (PVDF) with comparable piezoelectric properties to biaxially stretched β-PVDF.
Syntheses of C17–C27 fragments of 20-deoxybryostatins for assembly using Julia and metathesis reactions
Authors: Ball Matthew , Gregson Thomas , Omori Hiroki , Thomas Eric J.
Published: February 2017

Two approaches to the synthesis of compounds corresponding to the C17–C27 fragment of the 20-deoxybryostatins are described.
A formal homo-Nazarov cyclization of enantioenriched donor–acceptor cyclopropanes and following transformations: asymmetric synthesis of multi-substituted dihydronaphthalenes
Authors: Takada Seijiro , Takaki Naoya , Yamada Kenta , Nishii Yoshinori
Published: February 2017

Multi-substituted trans-dihydronaphthalenes were obtained in high ee from a TiCl4-mediated cyclization of enantioenriched D–A cyclopropanes, followed by a triflation of OH.
Synthesis of N,N-disubstituted 2-aminothiophenes by the cyclization of gem-difluoroalkenes with β-keto thioamides
Authors: Zhang Xuxue , Wu Mingsheng , Zhang Juan , Cao Song
Published: February 2017

A novel and effective method for the construction of highly functionalized aminothiophenesviathe cyclization ofgem-difluoroalkenes with β-keto tertiary thioamides is described.
Selective separation of oil and water with special wettability mesh membranes
Authors: Liu Defei , Yu Yuanlie , Chen Xin , Zheng Yuying
Published: February 2017

We fabricated superhydrophobic/superoleophilic and oleophobic/superhydrophilic membranes for the selective removal of oil or water from different oil/water mixtures. Both of the membranes are encouraging candidates for oil/water separation.
Efficiency and stability enhancement of inverted perovskite solar cells via the addition of metal nanoparticles in the hole transport layer
Authors: Kakavelakis G. , Alexaki K. , Stratakis E. , Kymakis E.
Published: February 2017

Inverted perovskite solar cells with enhanced efficiency and stability are fabricated based on a nanoparticles doped hole transport layer.
Controlling structural and magnetic properties of IONPs by aqueous synthesis for improved hyperthermia
Authors: Bonvin Debora , Arakcheeva Alla , Millán Angel , Piñol Rafael , Hofmann Heinrich , Mionić Ebersold Marijana
Published: February 2017

Introducing a hydrothermal step after coprecipitation leads to iron oxide nanoparticles with higher vacancy ordering, saturation magnetization and specific absorption rate.
Electrode buffer layers producing high performance nonvolatile organic write-once-read-many-times memory devices
Authors: Kong Zhiguo , Liu Dongxue , He Jinghan , Wang Xiuyan
Published: February 2017

CuI and Bphen buffer layers result in decreased switch threshold voltage and an increased ON/OFF ratio of an organic WORM memory device.
Synthesis, optical and electrochemical properties, and photovoltaic performance of a panchromatic and near-infrared (D)2–π–A type BODIPY dye with pyridyl group or cyanoacrylic acid
Authors: Ooyama Yousuke , Kanda Masahiro , EnoKi Toshiaki , Adachi Yohei , Ohshita Joji
Published: February 2017

(D)2–π–A type BODIPY dyes bearing a pyridyl group or cyanoacrylic acid group and two diphenylamine–thienylcarbazole moieties which possess near-infrared adsorption ability as well as panchromatic adsorption ability, have been developed.
Correction: Rhizoremediation of petroleum hydrocarbon, prospects and future
Authors: Shahzad Asim , Siddiqui Samina , Bano Asghari
Published: February 2017

Correction for ‘Rhizoremediation of petroleum hydrocarbon, prospects and future’ by Asim Shahzad et al., RSC Adv., 2016, 6, 108347–108361.
Correction: Titania nanotubes infiltrated with the conducting polymer PEDOT modified by Prussian blue – a novel type of organic–inorganic heterojunction characterised with enhanced photoactivity
Authors: Siuzdak K. , Szkoda M. , Karczewski J. , Ryl J. , Lisowska-Oleksiak A.
Published: February 2017

Correction for ‘Titania nanotubes infiltrated with the conducting polymer PEDOT modified by Prussian blue – a novel type of organic–inorganic heterojunction characterised with enhanced photoactivity’ by K. Siuzdak et al., RSC Adv., 2016, 6, 76246–76250.
Correction: Electrochemical promotion of catalysis over Pd nanoparticles for CO2 reduction
Authors: Cai Fan , Gao Dunfeng , Zhou Hu , Wang Guoxiong , He Ting , Gong Huimin , Miao Shu , Yang Fan , Wang Jianguo , Bao Xinhe
Published: February 2017

Correction for ‘Electrochemical promotion of catalysis over Pd nanoparticles for CO2 reduction’ by Fan Cai et al., Chem. Sci., 2017, DOI: 10.1039/c6sc04966d.
A mechanochemical synthesis of submicron-sized Li2S and a mesoporous Li2S/C hybrid for high performance lithium/sulfur battery cathodes
Authors: Li Xiang , Gao Mingxia , Du Wubin , Ni Bo , Wu Yuanhe , Liu Yongfeng , Shang Congxiao , Guo Zhengxiao , Pan Hongge
Published: February 2017

Li2S is synthesized by ball-milling LiH and S, which is further used for the synthesis of high performance lithium–sulfur battery Li2S/C cathodes.
Hydrogen evolution electrocatalysis with binary-nonmetal transition metal compounds
Authors: Hu Jue , Zhang Chengxu , Meng Xiangyue , Lin He , Hu Chen , Long Xia , Yang Shihe
Published: February 2017

The ground breaking studies of the past several years have ushered in a golden era of binary nonmetal transition metal compounds (BN-TMCs) in HER electrocatalysis. Here, we round up the recent developments in BN-TMCs from the viewpoint of its tunable physicochemical properties.
Analysis, design and implementation of a residential inductive contactless energy transfer system with multiple mobile clamps
Authors: Momeneh Arash , Castilla Miguel , Moradi Ghahderijani Mohammad , Miret Jaume , García de Vicuña Luis
Published: February 2017

This study presents the analysis, design and implementation of a simple and cost‐effective residential inductive contactless energy transfer system with multiple mobile clamps. The topology is based on the cascaded connection of a buck converter and a high‐frequency resonant inverter loaded by several output passive rectifiers. The proposed system includes a sliding transformer to supply the mobile loads, leading to a safe and flexible location of loads. The theoretical analysis and design of the proposed system is based on a mathematical model derived using the first harmonic approximation. Selected experimental results are included to verify the system features. In comparison with conventional topology, the proposed system significantly improves efficiency, complexity and cost.
Systematic Review of the Surgical Treatment of Extremity Lymphedema
Authors: Carl Hannah , Walia Gurjot , Bello Ricardo , Clarke-Pearson Emily , Hassanein Aladdin , Cho Brian , Pedreira Rachel , Sacks Justin
Published: February 2017

Background Although conservative management of lymphedema remains the first-line approach, surgery is effective in select patients. The purpose of this study was to review the literature and develop a treatment algorithm based on the highest quality lymphedema research.

Methods A systematic literature review was performed to examine the surgical treatments for lymphedema. Studies were categorized into five groups describing excision, liposuction, lymphovenous anastomosis (LVA), vascularized lymph node transfer (VLNT), and combined/multiple approaches. Studies were scored for methodological quality using the methodological index for nonrandomized studies (MINORS) scoring system.

Results A total of 69 articles met inclusion criteria and were assigned MINORS scores with a maximum score of 16 or 24 for noncomparative or comparative studies, respectively. The average MINORS scores using noncomparative criteria were 12.1 for excision, 13.2 for liposuction, 12.6 for LVA, 13.1 for VLNT, and 13.5 for combined/multiple approaches. Loss to follow-up was the most common cause of low scores. Thirty-nine studies scoring > 12/16 or > 19/24 were considered high quality. In studies measuring excess volume reduction, the mean reduction was 96.6% (95% confidence interval [CI]: 86.2–107%) for liposuction, 33.1% (95% CI: 14.4–51.9%) for LVA, and 26.4% (95% CI: − 7.98 to 60.8%) for VLNT. Included excision articles did not report excess volume reduction.

Conclusion Although the overall quality of lymphedema literature is fair, the MINORS scoring system is an effective method to isolate high-quality studies. These studies were used to develop an evidence-based algorithm to guide clinical practice. Further studies with a particular focus on patient follow-up will improve the validity of lymphedema surgery research.
Thin resolver using the easy magnetization axis of the grain-oriented silicon steel as an angle indicator
Authors: Oshino Jisho , Sasada Ichiro
Published: February 2017

A new type of thin resolver is presented, in which the easy axis of the magnetic anisotropy in the grain-oriented silicon steel is used as an angle indicator. The total thickness including a rotor, PCB coils and a back yoke can be made less than 4 mm. With a rotor of 50 mm diameter, a good linear response (non-linearity error < 0.4%) between the mechanical angle input and the electrical angle output has been obtained. The influence of a weak magnetic anisotropy in the non-grain-oriented silicon steel used for the back yoke on the accuracy of the resolver can be deleted by the method proposed in this paper.
The Ethics of “Choosing Wisely”: The Use of Neuroimaging for Uncomplicated Headache
Authors: Cote David J. , Laws Edward R.
Published: February 2017

The use of magnetic resonance imaging (MRI) for evaluation of headache remains excessive among physicians across many specialties according to both the American Headache Society and the American College of Radiology, despite recent attempts at limiting overuse of imaging and procedures. As part of the Choosing Wisely campaign, both of these organizations have explicitly recommended against imaging in patients with uncomplicated or typical migraine headaches. Yet, the practice nevertheless remains prevalent, with estimates ranging from 12.4% to 15.9% of patients with uncomplicated headache receiving MRI in outpatient practices. The low prevalence of serious pathological findings on imaging in patients who present without other indicative symptoms and the high cost of such exams necessitates a thorough evaluation of appropriate use of MRI for headache. Here, we debate the problematic use of MRI for uncomplicated headache and put forth a discussion of possible interventions that could promote more efficient use of imaging. Overuse of imaging has the potential to open a box that cannot readily be closed, and physicians upstream of surgical decision making must remain aware of the downstream effects of their clinical choices.
First Report of Squash vein yellowing virus in Watermelon in Guatemala
Authors: Jeyaprakash Ayyamperumal , Baker Carlye A. , Schubert Timothy S. , Badillo-Vargas Ismael E. , Roberts Pamela D. , Funderburk Joseph E. , Adkins Scott
Published: February 2017

Watermelon and other cucurbits are important crops grown in Guatemala for local consumption and export. This is the first report of SqVYV infecting watermelon in Central America.

Accepted for publication 14 July 2015. Published 15 July 2015.