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photometric investigation of eight ultra-short period eclipsing binaries from OGLE

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Research in Astronomy and Astrophysics 2020年第8期20卷 113-120页

作者： Shanti priya D. Ravi Raja p. Rukmini J. Raghu prasad M. Vineet S.thomas Department of Astronomy Osmania UniversityHyderabad-500007TelanganaIndia The University of Akron AkronOH44325USA

We performed a detailed photometric analysis of eight ultra-short period eclipsing binaries(USpEBs) using the Wilson-Devinney method. We present the modeled light curves and derived photometric solutions. The USpEBs with period(p)≤0.21 d considered in our study belong to W-subtype having shallow contact factor(f)~0.7 and later spectral types. The absolute parameters for these short-period binaries were derived applying empirical relations. We discuss the evolutionary stage of these USpEBs using the mass-radius, color-density and period-color diagrams. The objects showed poor metallicities, and some objects were even found to be existing around fully convective limits. The period distribution of USpEBs exhibited a sharp cut-off at 0.22 d;however, we observed significant deficits for our objects in the literature. We examined the statistics of USpEBs studied to date(in terms of the distribution of period, mass ratio and component temperatures of USpEBs) and observed that a dominant distribution of component temperatures for these USpEBs was towards lower temperatures.

关键词： stars:low-mass stars:evolution stars:low-mass binaries:eclipsing binaries:close

Investigations of ZnO thin films deposited by a reactive pulsed laser ablation

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Science China(Technological Sciences) 2009年第1期52卷 99-103页

作者： Y. C. SOO H. KANDEL M. A. thomas C. p. DAGHLIAN Department of physics and Astronomy University of Arkansas at Little Rock Little Rock E. M. Facilities Dartmouth College Hanover

Highly transparent ZnO thin films were deposited at different substrate temperatures by pulsed laser deposition in an oxygen atmosphere. The thin films were characterized by various techniques including X-ray diffraction, scanning electron microscopy, optical absorption, and photoluminescence. We demonstrated that oriented wurtzite ZnO thin films could be deposited at room temperature using a high purity zinc target. Variable temperature photoluminescence revealed new characteristics in the band edge emission. The underlying mechanism for the observed phenomena was also discussed.

关键词： thin films pulsed laser deposition optical property zinc oxide

Clinical and Bacteriological profile of Infections in Sickle Cell Children in Two Referral Hospitals in Niamey, Niger

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Open Journal of pediatrics 2024年第1期14卷 36-42页

作者： Kamaye Moumouni Samaila Aboubacar Garba Moumouni Georges thomas Ibrahim Mamoudou Abdou Djafar Mamane Halima Hamadou Ibrahim Hamani Issaka Djibrilla Almoustapha Amadou Yacouba Abdourahamane Marou Soumana Boubacar Moussa Saley Sahada Bade Malam Abdou Soumana Alido Service de pédiatrie A H&#244pital National de Niamey Niamey Niger Faculté des Sciences de la Santé Université Abdou Moumouni de Niamey Niamey Niger Service de pédiatrie H&#244pital national Amirou Boubacar Diallo Niamey Niger Service d’Onco-Hématologie H&#244pital national de Niamey Niamey Niger Service de Biologie Médicale H&#244pital national Amirou Boubacar Diallo Niamey Niger

Introduction: Infections are significant causes of mortality in sickle cell children in resource-limited countries. This study aimed to determine the clinical profile and bacterial ecology of infections in children with sickle-cell disease in two referral hospitals in Niamey. patients and methods: A retrospective descriptive study was conducted from January 2018 to July 2020 in two referral hospitals in Niamey. All children aged one (1) to 15 years with sickle cell disease admitted for suspected infection, including at least one bacterial culture, were studied. Bacteriological analysis was performed using the appropriate culture media, using BactAlert (Reference 4700003 BTA3D60 BioMérieux). Results: Over 36-months, 350 children with a mean age of 10.9 months were admitted. The sex ratio was 1.2. The SS electrophoretic profile was the most common (93.4%). Immunization status was up to date in 66% of patients. Fever was the common reason for consultation (55.1%). Infection was confirmed in 62 patients (17.7%). The primary diagnoses were bacterial gastroenteritis (24.2%) and urinary tract infection (19.4%). Blood cultures were isolated from Salmonella typhi (13.0%) and Escherichia coli (8.7%). Klebsiella spp (7.1%) and Escherichia coli (5.0%) were detected in cytobacteriological examination of urine. Salmonella typhi (23.5%) and Escherichia coli (5.9%) were isolated on coproculture. Conclusion: Bacterial ecology appears not different from that usually observed in sickle-cell children. Salmonella and Escherichia coli were predominant.

关键词： Sickle Cell Disease Child Infection Niger

Non-leaving-face property for marked surfaces

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Frontiers of Mathematics in China 2019年第3期14卷 521-534页

作者： thomas BRUSTLE Jie ZHANG Departement de Mathematiques Universite de Sherbrooke Sherbrooke J1K 2R1 Canada School of Mathematics and Statistics Beijing Institute of Technology Beijing 100081 China

Abstract We consider the polytope arising from a marked surface by flips of triangulations. D. D. Sleator, R. E. Tarjan, and W. p. Thurston [J. Amer. Math. Soc., 1988, 1(3): 647 681] studied the diameter of the associahedron, which is the polytope arising from a marked disc by flips of triangulations. They showed that every shortest path between two vertices in a face does not leave that face. We give a new method, which is different from the one used by V. Disarlo and H. parlier [arXiv: 1411.4285] to establish the same non-leaving-face property for all unpunctured marked surfaces.

关键词： Marked surface non-leaving-face property exchange graph

MIXED INTERIOR pENALTY DISCONTINUOUS GALERKIN METHODS FOR ONE-DIMENSIONAL FULLY NONLINEAR SECOND ORDER ELLIpTIC AND pARABOLIC EQUATIONS

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Journal of Computational Mathematics 2014年第2期32卷 107-135页

作者： Xiaobing Feng thomas Lewis Department of Mathematics The University of Tennessee Knoxville TN 37996 U.S.A. Department of Mathematics and Statistics The University of North Carolina at Greensboro NC 27402 U.S.A.

This paper is concerned with developing accurate and efficient numerical methods for one-dimensional fully nonlinear second order elliptic and parabolic partial differential equations （pDEs）. In the paper we present a general framework for constructing high order interior penalty discontinuous Galerkin （Ip-DG） methods for approximating viscosity solutions of these fully nonlinear pDEs. In order to capture discontinuities of the second order derivative uxx of the solution u, three independent functions p1,p2 and p3 are introduced to represent numerical derivatives using various one-sided limits. The proposed DG frame- work, which is based on a nonstandard mixed formulation of the underlying pDE, embeds a nonlinear problem into a mostly linear system of equations where the nonlinearity has been modified to include multiple values of the second order derivative uxz. The proposed framework extends a companion finite difference framework developed by the authors in [9] and allows for the approximation of fully nonlinear pDEs using high order polynomials and non-uniform meshes. In addition to the nonstandard mixed formulation setting, another main idea is to replace the fully nonlinear differential operator by a numerical operator which is consistent with the differential operator and satisfies certain monotonicity （called g-monotonicity） properties. To ensure such a g-monotonicity, the crux of the construction is to introduce the numerical moment, which plays a critical role in the proposed DG frame- work. The g-monotonicity gives the DG methods the ability to select the mathematically ＂correct＂ solution （i.e., the viscosity solution） among all possible solutions. Moreover, the g-monotonicity allows for the possible development of more efficient nonlinear solvers as the special nonlinearity of the algebraic systems can be explored to decouple the equations. This paper also presents and analyzes numerical results for several numerical test problems which are used to guage

关键词： Fully nonlinear pDEs Viscosity solutions Discontinuous Galerkin methods.

Evolution of gustatory reflex systems in the brainstems of fishes

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Integrative Zoology 2009年第1期4卷 53-63页

作者： thomas E.FINGER Department of Cell and Developmental Biology University of Colorado DenverAuroraUSA

The great number of species of teleosts permits highly specialized forms to evolve to occupy particular *** diversity allows for extreme variations in brain structure according to particular sensory or motor *** the case of the taste system,goldfish(Carassius auratus L.,1758)and some carps have evolved a specialized in-traoral food-sorting apparatus along with corresponding specializations of gustatory centers in the brainstem.A comparison of circuitry within the complex vagal lobe of goldfish,and of the simpler gustatory lobes in catfish(Ictalurus punctatus Rafinesque,1818)shows numerous similarities in organization and *** labeling studies using horseradish peroxidase and biotinylated dextran amine in catfish shows a direct projection from the vagal lobe to the motoneurons of nucleus ambiguus which innervate oropharyngeal ***,a three neuron reflex arc connects gustatory input to motor *** the vagal lobe of goldfish,a similar three neuron arc can be identified:from primary gustatory afferent,to vagal lobe interneuron,thence to dendrites of the vagal motoneurons that innervate the pharyngeal ***,despite large differences in the gross appearance of the vagal gustatory systems in the brains of catfish and goldfish,the essential connectivity and circuitry is *** suggests that evolutionary change in the central nervous system largely proceeds by rearrangement and elaboration of existing systems,rather than by addition of new structures or circuits.

关键词： evolution medulla nucleus of the solitary tract taste vagus nerve.

Helicobacter pylori:High dose amoxicillin does not improve primary or secondary eradication rates in an Irish cohort

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World Journal of Clinical Cases 2024年第16期12卷 2773-2779页

作者： Conor Costigan Aoife M O'Sullivan Jim O'Connell Shreyashee Sengupta thomas Butler Stephen Molloy Fintan John O'Hara Barbara Ryan Niall Breslin Sarah O'Donnell Anthony O'Connor Sinead Smith Deirdre McNamara Trinity Academic Gastroenterology Group School of Medicine-Trinity College DublinDublin D2Ireland Department of Gastroenterology Tallaght University HospitalDublin D24 NR0AIreland

BACKGROUND Helicobacter pylori(***)eradication rates have fallen globally,likely in large part due to increasing antibiotic resistance to traditional *** areas of high clarithromycin and metronidazole resistance such as ours,Maastricht VI guidelines suggest high dose amoxicillin dual therapy(HDADT)can be considered,subject to evidence for local *** this study we assess efficacy of HDADT therapy for *** eradication in an Irish *** To assess the efficacy of HDADT therapy for *** eradication in an Irish cohort as both first line,and subsequent therapy for patients diagnosed with *** All patients testing positive for *** in a tertiary centre were treated prospectively with HDADT(amoxicillin 1 g tid and esomeprazole 40 mg bid×14 d)over a period of 8 *** was confirmed with Urea Breath Test at least 4 wk after cessation of therapy.A delta-over-baseline>4%was considered *** demographics and treatment outcomes were recorded,analysed and controlled for basic demographics and prior *** *** One hundred and ninety-eight patients were identified with *** infection,10 patients were excluded due to penicillin allergy and 38 patients refused follow up *** all 139 were included in the analysis,55%(n=76)were female,mean age was 46.6 ***,93(67%)of patients were treatment-naïve and 46(33%)had received at least one previous course of *** groups were statistically ***-reported compliance with HDADT was 97%,mild side-effects occurred in 7%.There were no serious adverse drug *** the eradication rate for our cohort was 56%(78/139).Eradication rates were worse for those with previous treatment[43%(20/46)vs 62%(58/93),p=0.0458,odds ratio=2.15].Age and Gender had no effect on eradication *** Overall eradication rates with HDADT were *** being a simple and possibly better tolerated regime,these results do not

关键词： Helicobacter pylori eradication Helicobacter pylori High dose amoxicillin High dose amoxicillin dual therapy Triple therapy

Self-energy dynamics and the mode-specific phonon threshold effect in Kekulé-ordered graphene

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National Science Review 2022年第5期9卷 81-88页

作者： Hongyun Zhang Changhua Bao Michael Schüler Shaohua Zhou Qian Li Laipeng Luo Wei Yao Zhong Wang thomas p.Devereaux Shuyun Zhou State Key Laboratory of Low-Dimensional Quantum physics and Department of physics Tsinghua University Stanford Institute for Materials and Energy Sciences (SIMES) SLAC National Accelerator Laboratory Department of Materials Science and Engineering Stanford University Institute for Advanced Study Tsinghua University Frontier Science Center for Quantum Information

Electron-phonon interaction and related self-energy are fundamental to both the equilibrium properties and non-equilibrium relaxation dynamics of *** ele ctron-phonon interaction has been suggested by various time-resolved measurements to be important for the relaxation dynamics of graphene,the lack of energy-and momentum-resolved self-energy dynamics prohibits direct identification of the role of specific phonon modes in the relaxation ***,by performing time-and angle-resolved photoemission spectroscopy measurements on Kekulé-ordered graphene with folded Dirac cones at the Γ point, we have succeeded in resolving the self-energy effect induced by the coupling of electrons to two phonons at Ω=177 meV and Ω=54 meV,and revealing its dynamical change in the time ***,these strongly coupled phonons define energy thresholds,which separate the hierarchical relaxation dynamics from ultrafast,fast to slow,thereby providing direct experimental evidence for the dominant role of mode-specific phonons in the relaxation dynamics.

关键词： TrARpES self-energy electron-phonon coupling Kekulé-ordered graphene

Synergistic effect of fluorination on both donor and acceptor materials for high performance non-fullerene polymer solar cells with 13.5% efficiency

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Science China Chemistry 2018年第5期61卷 531-537页

作者： Qunping Fan Wenyan Su Yan Wang Bing Guo Yufeng Jiang Xia Guo Feng Liu thomas p.Russell Maojie Zhang Yongfang Li State and Local Joint Engineering Laboratory for Novel Functional polymeric Materials Laboratory of Advanced Optoelectronic Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China Department of physics and Astronomy Collaborative Innovation Center of IFSA Shanghai Jiao Tong University Shanghai 200240 China Materials Sctences Division Lawrence Berkeley National Laboratory Berkeley California 94720 United States CAS Research/Education Center for Excellence in Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

A high performance polymer solar cells(pSCs) based on polymer donor pM6 containing fluorinated thienyl benzodithiophene unit and n-type organic semiconductor acceptor IT-4 F containing fluorinated end-groups were developed. In addition to complementary absorption spectra(300–830 nm) with IT-4 F, the pM6 also has a deep HOMO(the highest occupied molecular) level(-5.50 e V), which will lower the open-circuit voltage(V_(oc)) sacrifice and reduce the E_(loss) of the IT-4 F-based pSCs. Moreover, the strong crystallinity of pM6 is beneficial to form favorable blend morphology and hence to suppress recombination. As a result, in comparison with the pSCs based on a non-fluorinated D/A pair of pBDB-T:ITIC with a medium pCE of 11.2%, the pM6:IT-4 Fbased pSCs yielded an impressive pCE of 13.5% due to the synergistic effect of fluorination on both donor and acceptor, which is among the highest values recorded in the literatures for pSCs to date. Furthermore, a pCE of 12.2% was remained with the active layer thickness of up to 285 nm and a high pCE of 11.4% was also obtained with a large device area of 1 cm^2. In addition, the devices also showed good storage, thermal and illumination stabilities with respect to the efficiency. These results indicate that fluorination is an effective strategy to improve the photovoltaic performance of materials, as well as the both fluorinated donor and acceptor pair-pM6:IT-4 F is an ideal candidate for the large scale roll-to-roll production of efficient pSCs in the future.

关键词： polymer solar cells fluorine substitution non-fullerene wide bandgap conjugated polymer power conversion efficiency