bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concentration of low energy extremals
Authors: Flucher M. , Müller S. 
Published: July 2002

We study variational problems of the form

\sup \left\{\int _{\Omega }F\left(u\right):\int _{\Omega }\left|\nabla u\right|^{2} \leq \varepsilon ^{2},u = 0\text{ on }\partial \Omega \right\}

with small

ε

and

0 \leq F\left(t\right) \leq c\left|t\right|^{\frac{2n}{n - 2}}

on a domain of dimension

n ≥ 3

. The corresponding Euler Lagrange equation is a semilinear Dirichlet problem

\begin{gather*} - \Delta u = \lambda f\left(u\right)\text{ in }\Omega , \\
u = 0\text{ on }\partial \Omega
\end{gather*}

with

f = F'

and a large Lagrange multiplier

λ

. Our goal is to obtain qualitative information on the extremals

u_ε

for small

ε

. The integrand

F

can be nonconvex and discontinuous. Thus our results apply to nonlinear eigenvalue problems as well as to certain free-boundary problems.

Our starting point is a generalized Sobolev inequality that covers the classical Sobolev inequality and the isoperimetric inequality relating capacity and volume as special cases. Using a local version of this inequality we prove a generalized concentration-compactness alternative and show that as

ε → 0

the extremals concentrate at a single point. The local behaviour of the extremals near the concentration point depends only on

F

. On a microscopic scale they tend to an extremal for the generalized Sobolev constant on

ℝ^n

provided that

F

satisfies certain growth conditions at 0 and infinity.

Résumé
Nous étudions des problèmes variationnels

\sup \left\{\int _{\Omega }F\left(u\right):\int _{\Omega }\left|\nabla u\right|^{2} \leq \varepsilon ^{2},u = 0\text{ sur }\partial \Omega \right\}

où

ε

est petit et

0 \leq F\left(t\right) \leq c\left|t\right|^{\frac{2n}{n - 2}}

et

ω

est un domaine de dimension

n ≥ 3

. L'équation d'Euler–Lagrange correspondante est un problème de Dirichlet semilinéaire

\begin{gather*}
- \Delta u = \lambda f\left(u\right)\text{ in }\Omega , \\
u = 0\text{ on }\partial \Omega
\end{gather*}

où

f = F′

et

λ

est un multiplicateur de Lagrange grand. Notre objectif est d'obtenir des informations qualitatives concernant les solutions extrémales

u_ε

pour

ε

petit. La fonction

F

peut être non convexe et discontinue.

Nos résultats s'appliquent par conséquent à des problèmes aux valeurs propres non linéaires et à certains problèmes à frontière libre. Notre point de départ est une inégalité de Sobolev généralisée qui contient l'inégalité de Sobolev classique et l'inégalité isopérimétrique qui relie la capacité et le volume. En utilisant une version locale de cette inégalité nous démontrons une version généralisée de l'alternative concentration-compacitée de Lions et nous montrons que les solutions extrémales se concentrent en un seul point lorsque

ε → 0

. Le comportement local de ces solutions extrémales au voisinage du point de concentration dépend uniquement de

F

. A une échelle microscopique elle tend vers la solution extrémale de la constante de Sobolev généralisée dans

ℝ^n

à condition que

F

vérifie certaines conditions d'accroissement en zéro et à l'infini.
Evolution equations governed by families of weighted operators
Authors: Couchouron J.F. , Ligarius P. 
Published: July 2002

In order to develop a Lebesgue approach for the fully non-linear non autonomous evolution problem,

CP_{A}^{\alpha } = \left\{\frac{du}{dt} + \alpha \left(t\right)A_{\alpha }\left(t\right)u∍0\right\}

with

t\in I ⊆ [0,T]

, in an arbitrary Banach space

X

, we define an abstract

L^1

-comparison mode (called
coherence
) between multivalued time dependent families of operators

(A_α(s))_{s\in I}

and

(B_β(t))_{t\in J}

defined on compact subintervals

I

and

J

of

[0,T]

and weighted by functions

α

and

β

which belong to

L^∞([0,T];ℝ^+)

. The solutions of these problems are limit of discrete schemes and the crucial point is to define these approximations in a Lebesgue sense. The results about this Cauchy problem consist in existence of an evolution operator, integral inequalities (extending Bénilan's inequalities for integral solutions), and continuous properties; they extend the theory of evolution equations initiated at the beginning of the seventeenth by Crandall, Liggett, Bénilan, Kobayashi, Evans, ([10], [12], …), and include more recent generalizations as in [18] and [6]. This general study motivated by the observation problem of a heat exchanger (see [16]) where a

L^∞

control multiplies an unbounded operator, establishes in Theorem 3.4 a suitable continuity property with respect to the weak

^∗

topology on the weights (see applications in [3], [7], [20], …).

Résumé

Ce papier esquisse une approche de type Lebesgue des problèmes d'évolution pleinement non linéaires

CP_{A}^{\alpha } = \left\{\frac{du}{dt} + \alpha \left(t\right)A_{\alpha }\left(t\right)u∍0\right\}

avec

t\in I ⊆ [0,T]

dans un espace de Banach quelconque. Pour cela nous définissons un mode de comparaison (nommé
cohérence
) entre familles d'opérateurs multivoques

(A_α(s))_{s\in I}

et

(B_β(t))_{t\in J}

définies sur des sous-intervalles compacts

I

et

J

de

[0,T]

et pondérées par des fonctions

α

et

β

de

L^∞([0,T];ℝ^+)

. Pour les problèmes d'évolution considérés les solutions sont des limites de schémas discrets: le point crucial est alors de définir ces approximations sur un ensemble dénombrable de noeuds (et donc de mesure nulle) en un sens compatible avec une infinité de classes de fonctions Lebesgue intégrables générées par notre approche. Nous mettons ainsi en évidence pour les problèmes de Cauchy

CP_A^α

un opérateur d'évolution, des inégalités intégrales (généralisant les inégalités des solutions intégrales de Bénilan) et des propriétés de continuité: ces résultats étendent des travaux de Crandall, Liggett, Bénilan, Kobayashi, Evans, ([10], [12], …), et absorbent des généralisations plus récentes obtenues dans [18] et [6]. Cette étude motivée par un problème d'observabilité pour un échangeur thermique (voir [16]) où un contrôle

L^∞

agit multiplicativement sur un opérateur non borné, contient en outre (Théorème 3.4) une propriété de continuité vis-à-vis de la topologie

^∗

-faible des poids dans

L^∞

(cf. [3], [7], [20], … pour les applications).
Existence and uniqueness results on Single-Peaked solutions of a semilinear problem
Authors: Cao Daomin , Noussair Ezzat S. , Yan Shusen 
Published: July 2002

A one to one correspondence is established between the nondegenerate critical points of

Q(x)

in

Ω

and single peaked solutions of the problem

\begin{cases}
- \epsilon^{2}\Delta u + u = Q\left(x\right)u^{p - 1} & \text{in }\Omega \\
u > 0& \text{in }\Omega \text{ and }\\
u = 0 & \text{on }\partial \Omega
\end{cases}

where

Ω

is a bounded domain,

2 < p < (N + 2)/(N - 2)

,

\epsilon > 0

, and

Q(x) \in C(\overline \Omega) \cap C^{2}(\Omega)

.

In particular, we establish the uniqueness of the least energy solution when

Q(x)

attains its maximum in

\overline \Omega

at only one nondegenerate critical point in

Ω

.

Résumé

On établit une correspondance biunivoque entre les points critiques non-dégénérés de

Q(x)

en

ω

, et les solutions à un seul pic du problème

\begin{cases}
- \epsilon^{2}\Delta u + u = Q\left(x\right)u^{p - 1} & \text{in }\Omega \\
u > 0& \text{in }\Omega \text{ and }\\
u = 0 & \text{on }\partial \Omega
\end{cases}

où

Ω

est un domaine borné,

2 < p < (N + 2)/(N - 2)

,

\epsilon > 0

, et

Q(x) \in C(\overline \Omega) \cap C^{2}(\Omega)

.

En particulier, nous démontrons l’unicité de la solution de moindre énergie lorsque

Q(x)

achève son maximum dans

Ω

en un seul point critique non-dégénéré.
Qualitative properties of positive solutions of semilinear elliptic equations in symmetric domains via the maximum principle
Authors: Damascelli Lucio , Grossi Massimo , Pacella Filomena 
Published: July 2002

In this paper we study the positive solutions of the equation

−Δu + λu = f(u)

in a bounded symmetric domain

Ω

in

ℝ^N

, with the boundary condition

u = 0

on

∂Ω

. Using the maximum principle we prove the symmetry of the solutions

v

of the linearized problem. From this we deduce several properties of

v

and

u

; in particular we show that if

N = 2

there cannot exist two solutions which have the same maximum if

f

is also convex and that there exists only one solution if

f(u) = u^p

and

λ = 0

.

In the final section we consider the problem

−Δu = u^p + μu^q

in

Ω

with

u = 0

on

∂Ω

, and show that if

1 < p <\frac{N + 2}{N - 2}

,

q

on

]0,1[

there are exactly two positive solutions for

μ

sufficiently small and some particular domain

Ω

.

Résumé
Dans ce travail nous étudions les solutions positives du problème

\begin{cases}
- \Delta u + \lambda = f\left(u\right) & \text{dans }\Omega \\
u = 0 & \text{sur le bord }\Omega
\end{cases}

où

Ω

est un domaine borné et symétrique dans

ℝ^N

.

Avec l’aide du principe de maximum nous prouvons la symétrie des solutions

v

du problème linéarisé. A partir de ce résultat nous déduisons plusieurs propriétés de

v

et

u

; en particulier nous montrons que si

f

est convexe et

N = 2

on ne peut pas avoir deux solutions différentes qui ont le même maximum. On prouve aussi qu’il y a une seule solution si

f(u) = u^p

et

λ = 0

.

Dans la dernière section nous étudions le problème

\begin{cases}
- \Delta u = u^{p} + \mu u^{q} & \text{dans }\Omega \\
u = 0 & \text{sur le bord de }\Omega
\end{cases}

et montrons que si

1 < p < N + 2/N − 2

,

0 < q < 1

et

μ

est petite il y a exactement deux solutions positives dans quelques domaines particuliers.
Spread of infection, in an animal model, after intramedullary nailing of an infected external fixator pin track
Authors: Clasper J. C. , Stapley S. A. , Bowley D. M. G. , Kenward C. E. , Taylor V. , Watkins P. E. 
Published: July 2002

AbstractImplant sepsis, due to previous external fixator pin track infection, is the most common complication of secondary intramedullary (IM) nailing of the tibia. We have developed an animal model, which allows different treatment methods to be studied. Using an established ovine model of a pin track infection, Staphylococcus aureus was used to infect the external fixator pins, two weeks prior to reamed IM nailing. In the control group, the animals were killed at a mean of 10.5 days following nailing, when widespread infection was evident, with septic arthritis, abscess formation, and infection of the entire length of the tibia in all six animals. In the treatment group, before IM nailing, the pin sites were débrided, and both local and systemic antibiotics were administered. All surgical wounds healed without evidence of infection, 4 of the 6 animals survived for 28 days, and bacteria were only isolated from 1 of the 6 implants. Treatment was successful at reducing, but not eliminating, infection after secondary nailing. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Glutamate dependent dendritic outgrowth in developing neuronal networks of rat hippocampal cells in vitro
Authors: Nuijtinck R.R.H. , Baker R.E. , Tergast E. , Struik M.L. , Mud M.T. 
Published: July 2002

AbstractThe present study was undertaken to determine whether release of glutamate is capable of influencing dendritic morphology in a developing network of rat hippocampal neurons in vitro. Control cultures developed a dense network of fibers and evinced spontaneous electrical activity from the third day in vitro. Dendrites were examined in cultures maintained for 2 weeks in vitro: the experimental group grown in medium containing the glutamate receptor antagonists AP‐5 and DNQX. Dendritic extensions were analyzed as a function of time (days in vitro) using a number of morphometric parameters, viz. the number of processes, the number and length of intermediate and terminal segments, as well as the total length of all segments. We found that the effect of age and treatment was most prominently reflected in the length of the terminal segments. Chronic addition of ionotropic glutamate receptor antagonists from day 2 in culture arrested all dendrite parameters at the prefunctional level. The results suggest that glutamate release is crucial for the onset of dendritic morphological development in hippocampal neurons.
Measuring Outcomes of Midwifery Care: Development of An Instrument To Assess Optimality
Authors: Murphy Patricia Aikins , Fullerton Judith T. 
Published: July 2002

ABSTRACTResearch on the outcomes of midwifery care is hampered by the lack of appropriate instruments that measure both process and outcomes of care in lower risk women. This article describes an effort to adapt an existing measurement instrument focused on the optimal outcomes of care (The Optimality Index—US) to reflect the contemporary style of U.S.‐based nurse‐midwifery practice. Evidence for content validity of the instrument was derived from literature reports of randomized clinical trials, synthetic reviews, and the clinical consensus of professional reviewers. Eleven perinatal health professionals and consumers, representing disciplines of obstetrics and gynecology, midwifery, epidemiology, and neonatology reviewed the instrument. The instrument was then applied to an existing data set of women who intended to give birth at home (N = 1,286 women) to determine its utility in measuring events in the process and outcome of perinatal health care as managed by nurse‐midwives. Results suggest that the tool holds promise for use in outcomes studies of U.S. perinatal care. Further testing of the instrument among diverse multicultural population groups, with various providers, and in diverse birth settings is warranted.
Protective behavioral strategies for sexual aggression and risky sexual behavior
Authors: Treat Teresa A. , Corbin William R. , Viken Richard J. 
Published: January 2021

AbstractSexual aggression (SA) is a serious public‐health problem on college campuses, and there is a pressing need for basic research fostering the development of novel prevention strategies. The current study (a) developed measures of protective behavioral strategies (PBS) for sexual aggression (SA) and risky sex (RS); (b) characterized college men's PBS use; and (c) evaluated whether those who reported engaging in SA and RS showed lower PBS use. Undergraduate men from two universities (n = 567) who endorsed sexual attraction toward women completed measures of PBS, SA, RS, rape‐supportive and sociosexual attitudes, and alcohol consumption. On average, participants reported using PBS for SA and RS fairly often, but a sizeable number indicated that they seldom or never used the strategies. Men who reported SA engagement in the last year, relative to their peers, endorsed sharply lower reliance on SA PBS and RS PBS. Men who reported at least one RS behavior in the last year used RS PBS far less often than their peers. The PBS measures converged as expected with other attitudinal and behavioral measures. The new PBS measures reference cognitive‐behavioral approaches that a large percentage of college men use on a regular basis, making them potentially acceptable prevention targets. Further, men at greater risk of exhibiting SA are much less likely to take steps to reduce the risks associated with sexual behavior, in comparison with their peers. Thus, future work could evaluate the potential usefulness of incorporating PBS for SA and RS into primary prevention programming in both domains.
Treatment planning and outcomes effects of reducing the preferred mean esophagus dose for conventionally fractionated non‐small cell lung cancer radiotherapy
Authors: Yorke Ellen D. , Thor Maria , Gelblum Daphna Y. , Gomez Daniel R. , Rimner Andreas , Shaverdian Narek , Shepherd Annemarie F. , Simone Charles B. , Wu Abraham , McKnight Dominique , Jackson Andrew 
Published: January 2021

AbstractBased on an analysis of published literature, our department recently lowered the preferred mean esophagus dose (MED) constraint for conventionally fractionated (2 Gy/fraction in approximately 30 fractions) treatment of locally advanced non‐small cell lung cancer (LA‐NSCLC) with the goal of reducing the incidence of symptomatic acute esophagitis (AE). The goal of the change was to encourage treatment planners to achieve a MED close to 21 Gy while still permitting MED to go up to the previous guideline of 34 Gy in difficult cases. We compared all our suitable LA‐NSCLC patients treated with plans from one year before through one year after the constraint change. The primary endpoint for this study was achievability of the new constraint by the planners; the secondary endpoint was reduction in symptomatic AE. Planners were able to achieve the new constraint in statistically significantly more cases during the year following its explicit implementation than in the year before (P = 0.0025). Furthermore, 38% of patients treated after the new constraint developed symptomatic AE during their treatment as opposed to 48% of the patients treated before. This is a clinically desirable endpoint although the observed difference was not statistically significant. A subsequent power calculation suggests that this is due to the relatively small number of patients in the study.
Bioorthogonal Coordination Polymer Nanoparticles with Aggregation‐Induced Emission for Deep Tumor‐Penetrating Radio‐ and Radiodynamic Therapy
Authors: Liu Jingjing , Hu Fang , Wu Min , Tian Longlong , Gong Fei , Zhong Xiaoyan , Chen Muchao , Liu Zhuang , Liu Bin 
Published: January 2021

AbstractRadiodynamic therapy (RDT), an emerging therapeutic approach for cancer treatment by employing ionizing irradiation to induce localized photodynamic therapy (PDT) can overcome the drawbacks of the limited penetration depth for traditional PDT and the unconcentrated energy in the tumor for traditional radiotherapy (RT). Taking advantage of aggregation‐induced emission (AIE) photosensitizers with bright fluorescence and efficient singlet oxygen production in the aggregate state, Hf‐AIE coordination polymer nanoparticles (CPNs), which show both strong RT and RDT effect under X‐ray irradiation, are developed. Furthermore, to enhance the tumor accumulation and prolong the tumor retention of the CPNs, bioorthogonal click chemistry is applied in the system through coupling between dibenzocyclooctyne (DBCO)‐modified CPNs (Hf‐AIE‐PEG‐DBCO) (PEG: poly(ethylene glycol)) and azide groups on the cell membrane formed by metabolic glycoengineering. Thanks to the high penetration of X‐ray irradiation, the bioorthogonal‐assisted RT and RDT combination therapy realizes significant killing of cancer cells without showing noticeable biotoxicity after intravenous administration of CPNs.
Techniques to Facilitate 3D Analysis of Self‐Organized Nanostructure Mechanism in Polymer/Fullerene Bulk Heterojunction Device
Authors: Nikiyan Ashkan , Komilian Soheil , Sadat‐Shafai Torfeh 
Published: January 2021

AbstractThe realization of solution processed polymer/fullerene as a constituent material for an active layer of solar cell raises a fundamental question relating to the nanostructure formation of these devices and its impact on a device's electrical parameters. To have an insight in nanomorphology and nanostructuring, Raman mapping of the scanned surface after each successive chemical etching is performed to build a picture of a vertical profile. To further support this technique, grazing incidence X‐ray diffraction (GIXRD) analysis on an etched surface is also performed. The data generated reveals an accurate correlation between these two techniques. To complete these investigations the impact of blend composition ratios on a nanostructure reveals that fullerene plays a critical role in self‐organization facilitating the rotation of a favorable face‐on the orientation to edge‐on allowing the migration of PC71BM towards the film surface. The impact of these investigations on electrical parameters has been addressed.
An Amorphous Spirobifluorene‐Phosphine‐Oxide Compound as the Balanced n‐Type Host in Bright and Efficient Light‐Emitting Electrochemical Cells with Improved Stability
Authors: Tang Shi , Larsen Christian , Ràfols‐Ribé Joan , Wang Jia , Edman Ludvig 
Published: January 2021

AbstractA rational host–guest concept design for the attainment of high efficiency at strong luminance from light‐emitting electrochemical cells (LECs) by suppression of exciton‐polaron quenching [Tang et al., Nature Communications 2017, 8, 1190] has been reported. However, a practical drawback with the presented host–guest LEC devices was that the operational stability is insufficient for many applications. Here, a systematic study is performed, revealing that a major culprit for the limited operational stability is that the employed n‐type host, 1,3‐bis[2‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazo‐5‐yl]benzene (OXD‐7), has a strong propensity for crystallization and that this crystallization results in a detrimental phase separation of the constituents in the active material during device operation. The authors, therefore, identify an alternative class of concept‐functional n‐type hosts in the form of spirobifluorene‐phosphine‐oxide compounds, and report that the replacement of OXD‐7 with amorphous 2,7‐bis(diphenylphosphoryl)‐9,9′‐spirobifluorene results in a much improved operational lifetime of 700 h at >100 cd m−2 during constant‐bias driving at an essentially retained high current efficacy of 37.9 cd A−1 and a strong luminance of 2940 cd m−2.
Artificial Neural Networks as Trial Wave Functions for Quantum Monte Carlo
Authors: Kessler Jan , Calcavecchia Francesco , Kühne Thomas D. 
Published: January 2021

AbstractInspired by the universal approximation theorem and widespread adoption of artificial neural network techniques in a diversity of fields, feed‐forward neural networks are proposed as a general purpose trial wave function for quantum Monte Carlo simulations of continuous many‐body systems. Whereas for simple model systems the whole many‐body wave function can be represented by a neural network, the antisymmetry condition of non‐trivial fermionic systems is incorporated by means of a Slater determinant. To demonstrate the accuracy of the trial wave functions, an exactly solvable model system of two trapped interacting particles, as well as the hydrogen dimer, is studied.
Flexible Artificial Memristive Synapse Constructed from Solution‐Processed MgO–Graphene Oxide Quantum Dot Hybrid Films
Authors: Chen Tong , Yang Siwei , Wang Jing , Chen Wei , Liu Lifu , Wang Yuan , Cheng Shijie , Zhao Xu 
Published: January 2021

AbstractInspired by the low energy consumption and highly parallel processing power of the biological neuromorphic system, the development of a brain‐inspired computing paradigm with electronic devices based artificial synapse may play an essential role in eliminating the Von Neumann bottleneck. Among candidate electronic devices, memristive devices have shown great potential for artificial synapse because of its tunable resistive switching (RS) behaviors. Herein, a biological synapse with solution‐processed MgO‐graphene oxide quantum dots (MgO‐GOQDs) based memristor is developed. The device exhibits highly controllable RS behavior owing to the enhancement of the local electric field by GOQDs and redox of GOQDs under electric fields. Moreover, essential biosynaptic functions including paired‐pulse facilitation, short‐term plasticity (STP)/long‐term plasticity (LTP), STP to LTP transition, and spike‐time‐dependent plasticity are successfully emulated. It is noteworthy that the device fabricated on a polyethylene terephthalate substrate also presents stable RS behavior after a large number of bending cycles. This study demonstrates the great potential of solution‐processed MgO–GOQD hybrid film on its application for the realization of flexible artificial neural networks.