检索结果-南通市图书馆

Analysis of TESS field Eclipsing Binary Star V948 Her: A Pulsating or Non-pulsating Star?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第1期22卷 137-147页

作者： f Kahraman Alicavus O Ekinci Canakkde Onsekiz Mart University Faculty of Sciences and ArtsPhysics Department17100QanakkaleTurkey Canakkale Onsekiz Mart University Astrophysics Research Center and Ulupinar ObservatoryTR-17100CanakkaleTurkey Canakkale Onsekiz Mart University School of Graduate StudiesDepartment of Space Sciences and TechnologiesTR-17100CanakkaleTurkey

Pulsating stars occupy a significant place in the H-R diagram and it was thought that all stars inside the classical instability strip should pulsate. However, recent studies showed that there are many non-pulsating stars located inside the classical instability strip. The existence of these non-pulsating stars is still a mystery. To deeply understand the properties of these non-pulsating and pulsating stars, one needs precise fundamental stellar parameters(e.g. mass).for this purpose, the eclipsing binaries are unique systems. Hence, in this study, we present the TESS data analysis of one candidate pulsating eclipsing binary system, V948 Her. TESS data were used for the binary modeling with the literature radial velocity measurements, and the precise fundamental parameters of the system were obtained. The system’s age was derived as 1 ± 0.24 Gyr. The positions of the binary components in the H-R diagram were examined and the primary component was found inside the δ Scuti instability strip. However, in the frequency analysis of TESS data, we found no significant pulsation frequencies. Only the harmonics of the orbital periods were obtained in the analysis. Therefore, the system was classified as a non-pulsator. V948 Her is an important object to understand the nature of non-pulsating stars inside the δ Scuti instability strip.

关键词： (stars:)binaries:eclipsing stars:fundamental parameters techniques:photometric

Multilevel Modelling for Surgical Tool Calibration Using LINEX Loss function

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第10期73卷 1691-1706页

作者： Mansour f.Yassen Department of Mathematics College of Science and Humanities in Al-AflajPrince Sattam Bin Abdulaziz UniversityAl-Aflaj11912Saudi Arabia Department of Mathematics Faculty of ScienceDamietta UniversityNew Damietta34517DamiettaEgypt

Quantifying the tool–tissue interaction forces in surgery can be utilized in the training of inexperienced surgeons,assist them better use surgical tools and avoid applying excessive *** voltages read from strain gauges are used to approximate the unknown values of implemented *** this objective,the force-voltage connection must be quantified in order to evaluate the interaction forces during *** progress of appropriate statistical learning approaches to describe the link between the genuine force applied on the tissue and numerous outputs obtained from sensors installed on surgical equipment is a key *** this study,different probabilistic approaches are used to evaluate the realized force on tissue using voltages read from strain gauges,including bootstrapping,Bayesian regression,weighted least squares regression,and multi-level *** from the proposed models are more precise than the maximum likelihood and restricted maximum likelihood *** suggested methodologies are proficient of assessing tool-tissue interface forces with an adequate level of accuracy.

关键词： Surgical tool weighted least squares multi-level modelling Bayesian approach

Some facets of the Mg/Na_(3)VCr_(0.5)fe_(0.5)(PO_(4))_(3) battery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第10期35卷 469-473页

作者： Gregorio f.Ortiz Xiamen Key Laboratory of Optoelectronic Materials and Advanced Manufacturing Institute of Luminescent Materials and Information DisplaysCollege of Materials Science and EngineeringHuaqiao UniversityXiamen 361021China

Magnesium rechargeable batteries(MRBs)present opportunities for grid-scale energy storage applications as a complement to Li-ion batteries(LIBS).The major challenges are the low reversible capacity,inferior cycling stability and unsatisfactory energy ***_(3)VCr_(0.5)fe_(0.5)(PO_(4))_(3) with a well-defined NASIONtype structure is used as cathode in Mg ***-electrons reaction(~116 m Ah/g),1.5 V average voltage and 65%of capacity retention over 100 cycles are *** is inserted by a biphasic reaction with the participation of V3+/V4+/V5+redox couples in the electrochemical reaction while the non-active redox couples such as Cr^(3+)/Cr^(4+)and fe^(2+)/fe^(3+)served as stabilizer to buffer the volume variation.A thermal stability up to~412℃ is also ***,incorporating a mixture of three transition metal(V/Cr/fe)in this type of structures will broaden new perspectives for realizing high performance cathodes for MRBs.

关键词： Multi-electron reaction Mg batteries NASICON Na_(3)VCr_(0.5)fe_(0.5)(PO_(4))_(3) Ironand chromium doping

Kinetics of the Reaction of 2-Chloro-3,5-dinitrobenzotriflouride with Aniline in Toluene and Methanol-Toluene Mixed Solvents

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2012年第1期30卷 109-114页

作者： fathalla Magda f. Chemistry Department Faculty of ScienceAlexandria UniversityP.O.426 IbrahimiaAlexandria 21321Egypt

Kinetics of the reaction of 2-chloro-3,5-dinitrobenzotriflouride with aniline were studied in toluene, metha- nol-toluene binary solvents, benzene and chloroform. The reaction in toluene exhibits third-order kinetics consistent with aggregates of aniline. Thermodynamic parameters AH#, AS# and AG# are calculated and discussed for the reaction of 2-chloro-3,5-dinitrobenzotriflouride with aniline in methanol-toluene. Molecular complexes between aniline and the substrate are rejected spectrophotometricaly. The mechanism is studied and compared with the reac- tion in presence of pyridine. It shows an amine dependence and formation of homo and/or hetero mixed aggregates between aniline and pyridine i.e. dimer mechanism.

关键词： kinetics 2-chloro-3,5-dinitrobenzotriflouride methanol-toluene

THERMODYNAMIC VARIATIONAL APPROACH fOR CLIMB Of AN EDGE DISLOCATION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2009年第5期22卷 426-435页

作者： A.C.f.Cocks Department of Engineering Science University of OxfordParks RoadOxfordOX1 3PJUK

A general thermodynamic variational approach is applied to study the force on an edge dislocation, which drives the dislocation to climb. Our attention is focused on the physical mechanism responsible for dislocation climb. A dislocation in a material element climbs as a result of vacancies diffusing into or out from the dislocation core, with the dislocation acting as a source or a sink for vacancy diffusion in the material element. The basic governing equations for dislocation climb and the climb forces on the dislocation are obtained naturally as a result of the present thermodynamic variational approach.

关键词： dislocation climb driving forces variational principle

Uncertainty relations for general phase spaces

在线全文

学校读者我要写书评

暂无评论

frontiers of physics 2016年第3期11卷 51-60页

作者： Reinhard f. Werner Institut fiir Theoretische Physik Leibniz Universitiit Hannover Germany

We describe a setup for obtain!ing uncertainty relations for arbitrary pairs of observables related by a fourier transform. The physical examples discussed here are the standard position and momentum, number and angle, finite qudit systems, and strings of qubits for quantum information applications. The uncertainty relations allow for an arbitrary choice of metric for the outcome distance, and the choice of an exponent distinguishing, e.g., absolute and root mean square deviations. The emphasis of this article is on developing a unified treatment, in which one observable takes on values in an arbitrary locally compact Abelian group and the other in the dual group. In all cases, the phase space symmetry implies the eciuality of measurement and preparation uncertainty bounds. There is also a straightforward method for determining the optimal bounds.

关键词： uncertainty relations phase space measurement uncertainty

Premature axon-oligodendrocyte interaction contributes to stalling of experimental axon regeneration after injury to the white matter

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 469-470页

作者： Ephraim f.Trakhtenberg Department of Neuroscience University of Connecticut School of MedicineFarmingtonCTUSA

Studies from nearly 3 decades ago suggested that,in the central nervous system(CNS),myelination of axons by oligodendrocytes not only helps improve axonal conductivity but also stabilizes circuitry(Colello and Schwab,1994).Over the years,myelin sheaths produced by oligodendrocytes have been found to contain multiple molecules that are inhibitory to axonal growth(e.g.,MAG,NogoA,OMgp,Semaphorins)(Yiu and He,2006;Silver et al.,2014).After white matter injury in the adult CNS,myelin debris from damaged axons and dead oligodendrocytes accumulates in the forming glial scar and exposes these myelin-associated axon growth-inhibitory molecules to the injured axonal stumps,thereby contributing to the inhibition of axonal *** development,CNS axons reach their postsynaptic targets and stop growing before oligodendrocytes appear and myelinate them(foran and Peterson,1992;Dangata et al.,1996).Therefore,myelin-associated axon growth-inhibitory molecules interacting with already grown axons during myelination were thought to block axons from promiscuous sprouting and miswiring,thereby stabilizing neural circuitry in the CNS(Colello and Schwab,1994).

关键词： thereby white injury

Hebbian plasticity:the elusive missing link at the heart of Alzheimer’s disease pathogenesis?

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第1期18卷 123-124页

作者： Alexander f.Jeans Department of Pharmacology University of OxfordOxfordUK

The amyloid cascade hypothesis of Alzheimer’s pathogenesis:The amyloid cascade hypothesis of Alzheimer’s disease(AD)pathogenesis will shortly celebrate its thirtieth birthday(Hardy and Higgins,1992).Based on abundant genetic and biochemical evidence,it proposes that deposition of the amyloid-β(Aβ)peptide in brain parenchyma is an essential upstream trigger in AD pathogenesis that drives a cascade of events,specifically including the recruitment and pathological hyper-phosphorylation of the micro-tubule-associated protein tau,that culminate in derangement of synaptic function and,eventually,neuronal death.

关键词： pathogenesis Alzheimer eventually

fORGING ASIA′S GLOBAL TRANSPARK IN THE PEARL RIVER DELTA AT ZHUHAI

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2003年第4期13卷 300-309页

作者： Victor f S SIT .

The main purpose of the paper is to introduce the concept of the Global TransPark (GTP). It is a critical time to develop air logistics infrastructure in the New Economy. The paper also presents a brief review of the air cargo industry in the Asian-Pacific region and China,in particular China’s development in the industry as its economy has grown rapidly and globalized in the past two decades. The paper argues that China needs to develop a GTP to support its future growth,and explains why the Pearl River Delta-Hong Kong-Macao city-region or Extended Metropolitan Region (EMR) is the best location. finally,it proposes that Zhuhai Airport,one of the five airports in the EMR,is the best site for the GTP. New policies from Chinese government as well as close cooperation between local governments of Guangdong and the two Special Administrative Regions of Hong Kong and Macao will be needed to make the establishment of the GTP possible.

关键词： Global TransPark airport air cargo transport Hong Kong Extended Metropolitan Region the Pearl River Delta New Economy