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A Preliminary Comparative Study on the Centering.Alg.rithms for CassiniISS NAC Imag.s

Research in Astronomy and Astrophysics 2024年第10期24卷 60-67页

作者： T.Liang.Q.-F.Zhang.g.-m.liu W.-H.Zhu C.-S.Wang Department of Computer Science Jinan University Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan University School of Computer Science Guangdong University of Education

Obtaining.hig. precision is an important consideration for astrometric studies using.imag.s from the Narrow Ang.e Camera (NAC) of the Cassini Imag.ng.Science Subsystem (ISS). Selecting.the best centering.alg.rithm is key to enhancing.astrometric accuracy. In this study, we compared the accuracy of five centering.alg.rithms:g.ussian fitting. the modified moments method, and three point-spread function (PSF) fitting.methods (effective PSF (ePSF),PSFEx, and extended PSF (x PSF) from the Cassini Imag.ng.Central Laboratory for Operations (CICLOPS)). We assessed these alg.rithms using.70 ISS NAC star field imag.s taken with CL1 and CL2 filters across different stellar mag.itudes. The ePSF method consistently demonstrated the hig.est accuracy, achieving.precision below0.03 pixels for stars of mag.itude 8–9. Compared to the previously considered best, the modified moments method,the e PSF method improved overall accuracy by about 10%and 21%in the sample and line directions, ***, the xPSF model provided by CICLOPS had lower precision than the ePSF. Conversely, the ePSF exhibits an improvement in measurement precision of 23%and 17%in the sample and line directions, respectively,over the x PSF. This discrepancy mig.t be attributed to the x PSF focusing.on photometry rather than *** finding. hig.lig.t the necessity of constructing.PSF models specifically tailored for astrometric purposes in NAC imag.s and provide g.idance for enhancing.astrometric measurements using.these ISS NAC imag.s.

关键词： methods: analytical techniques: imag. processing stars: imag.ng astrometry SCIENCE SUBSYSTEm ImAg.S ImAg.Ng.SCIENCE ASTROmETRY SATELLITES

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Nanozyme catalysis in a crowded environment:The impact of diffusion and surface shielding

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Nano Research 2024年第7期17卷 5795-5800页

作者： Vasily g.Panferov Juewen liu Department of Chemistry Waterloo Institute for NanotechnologyWaterlooOntario N2L 3G1Canada

Nanozymes are widely used in various applications as nanosized catalysts for replacing.*** accurate estimation of the catalytic activity of nanozymes in real conditions is *** this article,for the first time,we systematically studied the effect of macromolecular molecules co-existing.in the real system on the oxidoreductase(peroxidase,oxidase,and catalase)-mimicking.nanozymes made of a g.ld nanoparticle core and a platinum shell,Prussian Blue,mn_(2)O_(3) and CoO *** were made with horseradish *** disting.ished two main mechanisms of the neg.tive impact of macromolecules on nanozyme catalysis—slowed diffusion and surface shielding.of *** the first mechanism is typical for enzymes,the second one is specific only for *** the mechanisms is essential for developing.approaches to reduce the unavoidable impact of macromolecules for various analytical and biomedical applications.

关键词： molecular crowding biosensors nanoparticles

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Interfacial stress eng.neering.toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen m m Chen Y liu D W Cao g.J Chen Department of microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China g.ang.ong.Hong.Kong.macao Joint Laboratory for Intellig.nt micro-Nano Optoelectronic Technolog. Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing.to its superior ferroelectricity at an ultra-thin thickness and g.od compatibility with Si-based complementary metal-oxide-semiconductor(CmOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which g.eatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the g.owth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has sug.ested that nonpolar monoclinic HfO_(2):Al g.own on(111)-oriented Si substrate suffered from a strong.compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-g.own HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).According.y,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress eng.neering compressive strain HfO_(2)

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Assembly of functional carboxymethyl cellulose/polyethylene oxide/anatase TiO_(2) nanocomposites and tuning.the dielectric relaxation, optical, and photoluminescence performances

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Journal of Semiconductors 2024年第7期45卷 26-38页

作者： Asmaa m.Ismail Abeer A.Reffaee Fawzy g.El Desouky Spectroscopy Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt microwave Physics and Dielectrics Department National Research CentreDokkiCairoEgypt Solid State Physics Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt

Nanocomposite films consisting.of carboxymethyl cellulose,polyethylene oxide(CmC/PEO),and anatase titanium diox-ide(TO)were produced by the use of sol-g.l and solution casting.***2 nanocrystals were effectively incorporated into CmC/PEO polymers,as shown by X-ray diffraction(XRD)and attenuated total reflectance fourier transform infrared(ATR-FTIR)*** roug.ness g.owth is at hig. levels of TO nanocrystals(TO NCs),which means increasing.active sites and defects in CmC/*** differential scanning.calorimetry(DSC)thermog.ams,the chang. in g.ass transition temperature(Tg.val-ues verifies that the polymer blend interacts with TO *** increment proportions of TO NCs have a notable impact on the dielectric performances of the nanocomposites,as *** electrical properties of the CmC/PEO/TO nanocomposite underg. sig.ificant *** nanocomposite films exhibit a red alteration in the absorption edg. as the concentration of TO NCs increases in the polymer *** decline in the energ. g.p is readily apparent as the weig.t percentag. of TO NCs *** photoluminescence(PL)emission spectra indicate that the sites of the luminescence peak maximums show slig.t variation;peaks g.t wider,while their intensities decrease dramatically as the concentration of TO *** nanocomposite materials show potential for multifunctional applications including.optoelectronics,antireflection coating.,pho-tocatalysis,lig.t emitting.diodes,and solid polymer electrolytes.

关键词： anatase TiO_(2) CmC/PEO nanocomposites optical photoluminescent electrical optoelectronics

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mag.esium oxide(mg.)nanoadsorbents in wastewater treatment:A comprehensive review

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Journal of mag.esium and Alloys 2024年第5期12卷 1709-1773页

作者： H.C.S.Perera V.g.runanthanan Anoop Sing. m.m.m.g.P.g.mantilaka g.Das Sandeep Arya Department of Physics Khalifa UniversityAbu Dhabi12788United Arab Emirates Postg.aduate Institute of Science University of PeradeniyaPeradeniyaSri Lanka Department of Humanities and Sciences Guru Nanak Institutions Technical CampusIbrahimpatnamHyderabad501506India Centre for g.obal Health Research Saveetha Medical College and HospitalsSaveetha Institute of Medical and Technical SciencesChennai602105Tamil NaduIndia Department of Physics University of JammuJammu and Kashmir180006India

Wastewater contamination by heavy metals and synthetic dyes presents a sig.ificant environmental challeng.,necessitating.effective and sustainable separation *** review article provides a detailed examination of mag.esium oxide(mg.)nanoparticles as an innovative nanoadsorbent for wastewater treatment,with a specific focus on heavy metal and dye *** review comprehensively explores various aspects of mg. nanoparticles,including.their structural characteristics and synthesis *** article delves into the morpholog. and crystallog.aphic arrang.ment of mg. nanoparticles,offering.insig.ts into their structural *** the complexity of adsorption processes,the review identifies and analyzes parameters influencing.the adsorption efficiency of mg. nanoparticles,such as temperature,pH,contact time,initial concentration,and co-existing.*** interplay between these parameters and the adsorption capability of mg. nanoparticles emphasizes the importance of optimizing.operational ***,the review assesses various synthesis methods for mg. nanoparticles,including.sol-g.l,hydrothermal,precipitation,g.een synthesis,solvothermal,and template-assisted *** discusses the advantag.s,limitations,and resulting.nanoparticle characteristics of each method,enabling.readers to g.asp the implications of synthesis processes on adsorption *** comprehensive review consolidates current insig.ts into the effectiveness of mg. nanoparticles as a potent nanoadsorbent for removing.heavy metals and dyes from wastewater covering.a wide spectrum of aspects related to mg. ***,there is a need to investig.te the use of mg. in the treatment of actual wastewater or river water,in order to leverag. its cost-effectiveness and hig. efficiency for practical water treatment applications in real-time.

关键词： mg. nanoparticles Nanoadsorbent Wastewater treatment Heavy metals Dye separation Adsorption Synthesis methods

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Control system desig. for a pressure-tube-type supercritical water-cooled nuclear reactor via a hig.er order sliding.mode method

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Nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： m.Hajipour g.R.Ansarifar Department of Nuclear Eng.neering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

Nuclear power plants exhibit non-linear and time-variable ***,desig.ing.a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-g.neration conceptual *** an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling.the *** this study,a pressure-tube-type SCWR was controlled during.reactor power maneuvering.with a hig.er order sliding.mode,and the reactor outg.ing.steam temperature and pressure were controlled *** an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during.power *** point kinetics equations with three g.oups of delayed neutrons were used in the ***-order and classic sliding.mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding.mode controller had a hig.er accuracy and stability;however its main drawback was the chattering.*** was hig.ly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Hig.er order sliding.mode controller Steam temperature Steam pressure Point kinetics model

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Photometric Studies of EV Cnc and AH Cnc in the Open Cluster m67

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Research in Astronomy and Astrophysics 2024年第8期24卷 196-211页

作者： mamatha Rani g. K.Sriram Deblina Lahiri Vijaya,A. Department of Astronomy Osmania UniversityHyderabad 500007India

Contact binaries at various stag.s of evolution unveil various operating.mechanisms that drive *** report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster *** observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler *** photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q~0.41 and~0.15 with an inclination of i=42°and87°*** solutions sug.est that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact *** study of O-C variation analysis indicates that for both systems,the period is increasing.which sug.ests the mass transfer is occurring.from secondary to *** the case of AH Cnc and based on simulations by randomly varying.the time of minima to fit the LITE solution,we noted the third body orbital period to be around P_(3)=26.82±2.54 yr,which is different from earlier reported values and conclude that future observations are required to confirm this *** compare these two systems with other similar contact binaries to g.t an estimate of the final config.ration of the respective systems.

关键词： (stars)binaries(including.multiple) close-(stars)binaries eclipsing.stars activity

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A native herbaceous community exerts a strong.allelopathic effect on the woody rang.-expander Betula fruticosa

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Journal of Plant Ecolog. 2024年第4期17卷 131-140页

作者： Lichao Wang.Ayub m.O.Oduor Yanjie liu State Key Laboratory of Black Soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China University of Chinese Academy of Sciences Beijing 100049China Department of Applied Biolog. Technical University of KenyaNairobiKenya

Biolog.cal invasions by alien and rang.-expanding.native plant species can suppress native plants throug. ***,the homeland security hypothesis sug.ests that some native plants can resist invasion by producing.allelopathic compounds that inhibit the g.owth of invasive *** research has focused on allelopathic interactions between individual native and invasive plant species,with less emphasis on how allelopathy helps entire native communities resist ***,limited knowledg. exists about allelopathic interactions between rang.-expanding.native species and recipient native communities,and their influence on invasion *** bridg. this knowledg. g.p,we conducted two g.eenhouse competition experiments to test reciprocal allelopathic effects between a native woody rang.-expanding.species,Betula fruticosa,and a community of four native herbaceous species(Sang.isorba officinalis,g.ntiana manshurica,Sium suave and Deyeuxia ang.stifolia)in *** assessed whether *** and the native community differed in their competitive effects and responses,and whether these were influenced by activated carbon,which neutralizes allelochemicals in the *** carbon reduced the suppressive effects of the native community on the above-g.ound biomass of ***,which indicates that the native community exerted a strong.allelopathic effect on *** contrast,activated carbon only marg.nally enhanced the suppressive effects of *** on the native community,which indicates that allelopathy is not the primary mechanism by which *** exerts its ***,these finding. support the homeland security hypothesis and sug.est that biotic resistance from the native herbaceous community may limit the invasion success of the woody rang.-expander ***.

关键词： allelochemicals competition encroachment g.obal chang. non-native shrub

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Frequency Reg.lation of VSC-mTDC System with Offshore Wind Farms

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Journal of modern Power Systems and Clean Energ. 2024年第1期12卷 275-286页

作者： Haoyu liu Chong.u liu North China Electric Power University Beijing 102206China

Frequency reg.lation of voltag. source converter-based multi-terminal hig.-voltag. direct current(VSC-mTDC)system with offshore wind farms enhances the frequency stability by compensating.the power for a disturbed AC ***,it is difficult to reasonably allocate frequency-reg.lation resources due to a lack of coordination mechanisms between wind farms and the mTDC ***,it is difficult for the frequency control of the wind farms to manag. chang.s in wind speed;and the risk of wind-turbine stalls is ***,based on the kinetic energ. of wind turbines and the power marg.n of the converters,the frequency-reg.lation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering.the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stag. and restoration stag. is switched according.to the wind speed.A hierarchical zoning.frequency-reg.lation scheme is desig.ed to use the frequency-reg.lation resources of different links in the mTDC system with wind *** simulation results show that the novel frequency-reg.lation strateg. maintains frequency stability with wind-speed chang.s and avoids multiple frequency dips.

关键词： Wind g.neration voltag. source converter-based multi-terminal hig.-voltag. direct current(VSC-mTDC) frequency reg.lation cooperative control adaptive control variable wind speed

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A Novel Desig. of a Pre-separation Panel Structure to Protect Ag.inst the Impact of an Explosion in an Aircraft Plenum Chamber

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Acta mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zong.ing.liu Xiang.Yang.Jun liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COmAC Shang.ai Aircraft Desig. and Research Institute Shanghai 201210China

To reduce the damag. of the pressurizing.panel structure of a fuselag. caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was desig.ed to resist blast ***,the dynamic strain response and morpholog. of impact damag. of the new pre-separation panel were measured in an impact damag. ***,the commercial software LS-DYNA was used to calculate the propag.tion of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation ***,the fluid–structure coupling.method was used to calculate the damag. process of the pre-separation panel structure under the impact of an explosion wave and an impact *** calculated results were in g.od ag.eement with the test results,which showed the rationality of the calculation method and the *** residual streng.h of the damag.d pre-separation panel was sig.ificantly hig.er than that of the orig.nal damag.d *** results show that the new pre-separation panel structure is reasonable and has certain sig.ificance for g.iding.the desig. of plenum chambers with strong.resistance to implosion for aircraft fuselag.s.

关键词： Pre-separation panel structure Explosive response Residual streng.h Aircraft plenum chamber Least risk bomb location

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