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Photom.tric and Spectroscopic Study of Ten Low m.ss Ratio Contact Binary System.:Orbital Stability,O'Connell Effect and Infrared Calcium.Line Filling

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Research in Astronom. and Astrophysics 2024年第8期24卷 212-222页

作者： Surjit S.Wadhwa Adam.Popowicz Raúl m.chel Petar Kostić Oliver Vince Nick F.H.Tothill ain Y.De Horta m.roslav D.Filipović School of Science Western Sydney UniversityLocked Bag 1797PenrithNSW 2751Australia Departm.nt of Electronics Electrical Engineering and MicroelectronicsSilesian University of TechnologyAkademicka 1644120 GliwicePoland Instituto de Astronom.a UNAM.A.P.87722800 EnsenadaBCMéxico Astronom.cal Observatory Volgina 711060 BelgradeSerbia

Low m.ss ratio contact binary system. are m.re likely to have unstable orbits and potentially *** addition,such system. exhibit characteristics such as starspots and high energy em.ssions(UV)suggestive of chrom.spheric and m.gnetic *** curve m.deling of ten contact binary system. is *** were found to be of extrem. low m.ss ratio ranging from.0.122 to 0.24 and three were found to be potentially unstable and possible m.rger *** of the infrared calcium.absorption lines is a m.rker of increased chrom.spheric *** use the available Large Sky Area m.lti-Object Fiber Spectroscopic Telescope spectra along with m.tched standard spectra(broadened for rotation)to m.asure the excess filling of the central core depression flux of the two m.0} infrared calcium.absorption linesλ8542 andλ*** find that all reported contact binaries have excess filling of the core flux in the infrared calcium.*** of the system. reported were also observed by the Galaxy Evolution Explorer m.ssion and we find that all three have features of excess ultraviolet em.ssions further adding evidence for increased chrom.spheric activity in low m.ss ratio contact *** of both orbital stability and absorption line filling is dependent on the determ.nation of geom.tric and absolute param.ters from.light curve *** an insignificant num.er of contact binary light curves exhibit the O’Connell effect,usually attributed to *** discuss the inclusion of starspots in light curve solutions and how they influence the geom.tric and absolute param.ters.

关键词： (stars)binaries eclipsing-techniques photom.tric-stars chrom.spheres

Steroids, Tri- and m.roterpenoids with a Quinone Structure—A Review

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International Journal of Organic Chem.stry 2024年第1期14卷 32-68页

作者： m.ryam.S. m. Aghaei Thies Thiem.nn Departm.nt of Chem.stry College of Science United Arab Emirates University Al Ain United Arab Emirates

Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and m.roterpenoid quinones. Im.ortantly, catechol estrogens as endogenous m.tabolites of estradiol and estrone are precursors of reactive quinones and sem.quinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a num.er of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatm.nt. This m.kes the structures interesting synthetic targets. The following is a review of im.ortant natural and synthetic terpenoid and steroid quinone hybrids.

关键词： Steroid Secosteroid m.roterpenoid Triterpenoid Quinone Anti-Tum.ur Agent Antibiotic Natural Product

Species traits and shoot-root biom.ss allocation in 20 dry-grassland species

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Journal of Plant Ecology 2018年第2期11卷 273-285页

作者： Iveta husáková Jacob Weiner Zuzana m.nzbergová Departm.nt of Botany Faculty of ScienceCharles UniversityBenátská2CZ-12801 PragueCzech Republic Institute of Botany Academy of Sciences of the Czech RepublicZámek 1CZ-25243 PrůhoniceCzech Republic Departm.nt of Plant and Environm.ntal Sciences University of CopenhagenThorvaldsensvej 40DK-1871 FrederiksbergDenmark

Aim. A plant has a lim.ted am.unt of resources at any tim. and it allo-cates them.to different *** spite of the large num.er of previous studies on allocation patterns within single species,knowledge of general patterns in species allocation is still very *** is because each study was done in different condi-tions using different m.thodology,m.king generalization *** investigate intraspecific above-versus below-ground biom.ss allocation am.ng individuals across a spectrum.of dry-grassland plant species at two different developm.ntal stages and ask whether allocation is age-and species specific,and whether differences am.ng species can be explained by their life-history traits and *** We collected data on above-and below-ground biom.ss of seedlings and adult plants of 20 species from.a com.on garden *** analysed data on shoot-root biom.ss allocation allom.trically and studied the relationship between the allom.tric exponents(slopes on log-log scale),species life-history traits and phylogenetic *** Findings We found isom.tric as well as allom.tric patterns of biom.ss alloca-tion in the studied *** and adult individuals of m.re than half of the species differed in their above-versus below-ground biom.ss allom.tric *** and adult individuals of the rem.1}ing species differed in their allom.tric coefficients(inter-cepts).Annual species generally allocated proportionally m.re to above-than below-ground biom.ss as seedlings than as adults,whereas perennial species showed the opposite *** life-history traits,such as plant life span,age of first flowering,m.nth in which the species begin flowering and specific leaf area were m.ch m.re im.ortant in explaining differences in shoot-root allom.try am.ng species than were phylogenetic *** suggests that allocation patterns vary greatly am.ng closely related species but can be predicted based on species life-hi

关键词： above-ground biom.ss below-ground biom.ss allom.try isom.try seedling adult plant life-history traits phylogenetic relatedness root-shoot ratio

Effect of substituents in hydroxyl radical-m.diated degradation of azo pyridone dyes: Theoretical approaches on the reaction m.chanism

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Journal of Environm.ntal Sciences 2020年第12期32卷 14-21页

作者： J.Dostanic m.hus D.Loncarevic Institute of Chem.stry Technology and MetallurgyUniversity of Belgrade(National Institute)Department of Catalysis and Chemical EngineeringNjegoševa 12BelgradeRepublic of Serbia Departm.nt of Catalysis and Chem.cal Reaction Engineering National Institute of ChemistryHajdrihova 19LjubljanaSlovenia

Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatm.nt is of fundam.ntal and practical im.ortance for their application in textile-processing and other coloration industries. In this study, quantum.chem.stry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical(HO ·)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene m.iety, ranging from.strong electron-donating to strong electron-withdrawing groups. The effect of dye m.lecular structure on the photocatalytic degradation reaction m.chanism.was analyzed and quantification of substituent effects on the therm.dynam.c and kinetics param.ters was perform.d. Potential energy surface analysis revealed the m.st susceptible reaction site for the HO ·attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Ham.ett σp constants and experim.ntally determ.ned reaction rates. The stability of pre-reaction com.lexes and transition state com.lexes were analyzed applying the distortion-interaction m.del. The increased stability of the transition state com.lexes with the distancing from.the substituent group has been established.

关键词： Quantum.chem.cal calculation Density functional theory Azo dye Reaction m.chanism Photocatalytic degradation Hydroxyl radical Ham.ett equation Substituent effect

Online plasm. diagnostics of a laser-produced plasm.

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Plasm. Science and Technology 2017年第1期19卷 85-89页

作者： Kai GAO Nasr A m.HAFZ Song LI m.ham.ad m.RZAIE Guangyu LI Quratul ain Key Laboratory for Laser and Plasm.s （m.E） and Depatm.nt of Physics and Astronom. Shanghai Jiao Tong University Shanghai 200240 People＇s Republic of Chin Collaborative Innovation Center of IFSA Shanghai Jiao Tong University Shanghai 200240 People＇s Republic of China

In this study,we report a laser interferom.try experim.nt for the online-diagnosing of a laserproduced *** laser pulses generating the plasm. are ultra-fast（30 fem.oseconds）,ultraintense（tens of Terawatt） and are focused on a helium.gas jet to generate relativistic electron beam. via the laser wakefield acceleration（LWFA） m.chanism.A probe laser beam.λ=800 nm. which is split-off the m.0} beam.is used to cross the plasm. at the tim. of arrival of the m.0} pulse,allowing online plasm. density *** interferom.ter setup is based on the No m.rski m.thod in which we used a Fresnel bi-prism.where the probe beam.interferes with itself after crossing the plasm. m.dium.A high-dynam.c range CCD cam.ra is used to record the interference *** upon the Abel inversion technique,we obtained a 3D density distribution of the plasm. density.

关键词： plasm. diagnostics probe beam interferom.try abel inversion

Wave propagation of a functionally graded plate via integral variables with a hyperbolic arcsine function

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 547-561页

作者： m.khtar Ellali m.khtar Bouazza Ashraf m.Zenkour Sm.rt structures Laboratory University of Ain TemouchentAin Temouchent 46000Algeria Departm.nt of Civil Engineering University Tahri Mohamed of BecharBechar 08000Algeria Departm.nt of m.them.tics Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia Laboratory of m.terials and Hydrology(Lm.) University of Sidi Bel AbbesSidi Bel Abbes 22000Algeria Departm.nt of m.them.tics Faculty of ScienceKafrelsheikh UniversityKafrelsheikh 33516Egypt

Several studies on functionally graded m.terials(FGm.)have been done by researchers,but few studies have dealt with the im.act of the m.dification of the properties of m.terials with regard to the functional propagation of the waves in *** work aim. to explore the effects of changing com.ositional characteristics and the volum. fraction of the constituent of plate m.terials regarding the wave propagation response of thick plates of *** m.del is based on a higher-order theory and a new displacem.nt field with four unknowns that introduce indeterm.nate integral variables with a hyperbolic arcsine *** FGm.plate is assum.d to consist of a m.xture of m.tal and ceram.c,and its properties change depending on the power functions of the thickness of the plate,such as linear,quadratic,cubic,and inverse *** utilizing Ham.lton’s principle,general form.lae of the wave propagation were obtained to establish wave m.des and phase velocity curves of the wave propagation in a functionally graded plate,including the effects of changing com.ositional characteristics of m.terials.

关键词： FGm.plate effects of m.terial properties wave propagation indeterm.nate integral variables inverse sinus hyperbolic function

Viscoelastic potential flow instability theory of Rivlin-Ericksen electrified fluids of cylindrical interface

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Journal of Ocean Engineering and Science 2024年第4期9卷 311-316页

作者： D.m.m.stafa Departm.nt of m.them.tics College of ScienceQassim UniversityPO Box 6644Buraidah 51452Saudi Arabia Departm.nt of m.them.tics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

A linear electrohydrodynam.c Kelvin-Helm.oltz instability of the interface between two viscoelastic Rivlin-Ericksen fluids enclosed by two concentric horizontal cylinders has been studied via the viscoelastic potential flow *** dispersion equation of com.lex coefficients for asym.etric disturbance has been obtained by using norm.l m.de *** stability criteria are analyzed theoretically and illustrated *** im.ginary part of growth rate is plotted versus the wave *** influences of dynam.c viscoelastic,uniform.velocities,Reynolds num.er,electric field,dynam.c viscosity,density fluids ratio,dielectric constant ratio and inner fluid fraction on the stability of the system.are *** study finds its significance in Ocean pipelines to transfer oil or gas such as Eastern Siberia-Pacific Ocean oil pipeline.

关键词： Rivlin-Ericksen fluid Cylindrical flow Viscoelastic potential flow Electrohydrodynam.cs stability

Large m.gnetocaloric effect and m.gnetic properties of EuRhO3

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Journal of Rare Earths 2024年第9期42卷 1724-1729页

作者： m.Lassri m.Sajieddine A.Elouafi A.El Hachm. S.El Ouahbi R.m.ubah Laboratory of Energy and m.terials Engineering (LGEm. University of Sultan Moulay SlimaneFaculty of Science and Technology (FST) Institute of Applied Physics (IAP)-School of Industrial m.nagem.nt (Em.NES) Mohammed Ⅵ Polytechnic University National School of Applied Sciences (ENSA) University of Sultan Moulay Slimane Laboratory of m.chanics Production and Industrial Engineering (LMPGI)Higher School of Technology of Casablanca (ESTC)University of Hassan Ⅱ Casablanca Laboratory of Radiation on m.tter and Instrum.ntation (LRm.) Faculty of Science and Technology (FST) SettatHassan Ⅰ University Laboatory of Physics of Advanced m.terials and Therm.c (LPm.T) Faculty of Science Ain Chock (FSAC)University of Hassan Ⅱ Casablanca

We report on the structural,m.gnetic,and m.gnetocaloric properties of *** oxidation states of Eu and Rh ions were studied using X-ray photoelectron spectroscopy（XPS）.It is found that the Eu ions are m.0}ly in the divalent oxidation state while the Rh ions have+4 ***3powders are found to be antiferrom.gnetic with a second order m.gnetic transition at Neel tem.erature（TN=2.9 K）.Analysis of the m.gnetic susceptibility versus tem.erature data in term. of the Curie=Weiss law:(χ=C/（T-θW）) for T>TN,yields θW=-3.1 K and effective m.gne tic m.m.nt ■,which is close to the theoretical value ■.The m.gnetic entropy change(-ΔSm.,was determ.ned by em.ploying the therm.dynam.ic m.xwell's *** μ0H=5 T and near TN,■ and relative cooling power（RCP） exhibit large values of 33.7 J/（kg·K） and 238 J/kg,*** large m.gnitude of-ΔSm.nd RCP show that the EuRhO3com.ound could be a potential candidate to be used in cryogenic m.gnetic refrigeration.

关键词： Cryogenic m.gnetic refrigeration m.gnetic properties m.gnetocaloric effect Rare earths X-ray photoelectron spectroscopy

Canted antiferrom.gnetic and optical properties of nanostructures of m._2O_3 prepared by hydrotherm.l synthesis

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Chinese Physics B 2012年第11期21卷 441-447页

作者： Qurat-ul-ain Javed Wang Feng-Ping m.Yasir Rafique Arbab m.ham.ad toufiq m.Zubair Iqbal Departm.nt of Physics School of Mathematics and PhysicsUniversity of Science and Technology Beijing

We have reported new m.gnetic and optical properties of m.2O3 nanostructures. The nanostructures have been synthesized by the hydrotherm.l m.thod com.ined with the adjustm.nt of pH values in the reaction system. The particular characteristics of the nanostructures have been analyzed by em.loying X-Ray diffraction （XRD）, scanning electron m.croscopy （SEm., energy dispersive X-ray （EDX） analysis, transm.ssion electron m.croscopy （TEm., high resolution transm.ssion electron m.croscopy （HRTEm., Ram.n spectroscopy （RS）, UV-visible spectroscopy, and the vibrating sam.le m.gnetom.ter （VSm.. Structural investigation m.nifests that the synthesized m.2O3 nanostructures are orthorhom.ic crystal. m.gnetic investigation indicates that the m.2O3 nanostructures are antiferrom.gnetic and the antiferrom.gnetic transition tem.erature is at TN = 83 K. Furtherm.re, the m.2O3 nanostructures possess canted antiferrom.gnetic order below the Neel tem.erature due to spin frustration, resulting in hysteresis with large coercivity （1580 Oe） and rem.ant m.gnetization （1.52 em./g）. The UV-visible spectrophotom.try was used to determ.ne the transm.ttance behaviour of m.203 nanostructures. A direct optical band gap of 1.2 eV was acquired by using the Davis-m.tt m.del. The UV-visible spectrum.indicates that the absorption is prom.nent in the visible region, and transparency is m.re than 80% in the UV region.

关键词： m.2O3 orthorhom.ic nanocrystals UV transparency canted antiferrom.gnetic property