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Structural,electronic,magnetic and optical properties of neodymium chalcogenides using LSdA+U method

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Journal of Semiconductors 2012年第8期33卷 9-14页

作者： A Shankar d p rai Sandeep R K Thapa Condensed Matter Theory Group Department of PhysicsMizoram UniversityAizawlMizoram-796004India

We have studied the electronic, magnetic and optical properties of neodymium chalcogenides by performing LSdA＋ U and full potential linearized augmented plane wave （Fp-LApW） method. The electronic structure calculation shows that the electronic states in Nd-chalcogenides were mainly contributed by Nd-4f electrons near Fermi energy and 3p, 4p and 5p state electrons of X （S, Se and Te）, respectively. We have also studied the absorption of light via the imaginary parts of the dielectric function of Nd-chalcogenides.

关键词： dFT dOS magnetic moment U

Band-gap engineering of La1-xNdxAlO3(x = 0,0.25,0.50,0.75,1)perovskite using density functional theory：A modified Becke Johnson potential study

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Chinese physics B 2016年第6期25卷 376-382页

作者： Sandeep d p rai A Shankar M p Ghimire Anup pradhan Sakhya T p Sinha R Khenata S Bin Omran R K Thapa department of physics Mizoram University Aizawl-796004 India department of physics Pachhunga University College Aizawl-796001 India department of physics University of North Bengal Darjeeling-734013 India IFW dresden e. V. P. O. Box 270116 D-01171 Dresden Germany department of physics Bose Institute 93/1 Acharya Prafulla Chandra Road Kolkata 700009 India Laboratoire de physique Quantique et de Modelisation Mathematique (LpQ3M) Department de Technologie Universite de Mascara 29000 Mascara Algerie Algeria department of physics and Astronomy College of Science King Saud University P. O: Box 2455 Riyadh 11451 Saudi Arabia

The structural,electronic,and magnetic properties of the Nd-doped Rare earth aluminate,La1-xNdxAlO3（x = 0%to 100%） alloys are studied using the full potential linearized augmented plane wave（Fp-LApW） method within the density functional *** effects of the Nd substitution in La AlO3 are studied using the supercell *** computed electronic structure with the modified Becke–Johnson（m BJ） potential based approximation indicates that the La1-xNdxAlO3 alloys may possess half-metallic（HM） behaviors when doped with Nd of a finite density of states at the Fermi level（EF）.The direct and indirect band gaps are studied each as a function of x which is the concentration of Nddoped La *** calculated magnetic moments in the La1-xNdxAlO3 alloys are found to arise mainly from the Nd-4f state.A probable half-metallic nature is suggested for each of these systems with supportive integral magnetic moments and highly spin-polarized electronic structures in these doped systems at *** observed decrease of the band gap with the increase in the concentration of Nd doping in La AlO3 is a suitable technique for harnessing useful spintronic and magnetic devices.

关键词： density functional theory rare earth aluminates perovskites electronic structures

Optoelectronic and thermoelectric properties of Zintl YLi_(3)A_(2)(A = Sb,Bi) compounds through modified Becke-Johnson potential

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Chinese physics B 2016年第10期25卷 428-435页

作者： T Seddik G Ugur R Khenata S Ugur F Soyalp G Murtaza d p rai A Bouhemadou S Bin Omran department of physics and Astronomy College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia

In the present work,we investigate the structural,optoelectronic and thermoelectric properties of the YLi3X2(X = Sb,Bi) compounds using the full potential augmented plane wave plus local orbital(Fp-ApW+lo) *** exchangecorrelation potential is treated with the generalized gradient approximation/local density approximation(GGA/LdA) and with the modified Becke-Johnson potential(TB-mBJ) in order to improve the electronic band structure *** addition,the estimated ground state properties such as the lattice constants,external parameters,and bulk moduli agree well with the available experimental *** band structure calculations with GGA and LdA predict that both compounds have semimetallic ***,the band structure calculations with the GGA/TB-mBJ approximation indicate that the ground state of the YLi3Sb2compound is semiconducting and has an estimated indirect band gap(Γ-L) of about 0.036 eV while the ground state of YLi3Bi2compound is *** the LdA/TB-mBJ calculations indicate that both compounds exhibit semiconducting characters and have an indirect band gap(Γ-L) of about 0.15 eV and 0.081 eV for YLi3Sb and ***,the optical properties reveal strong responses of the herein materials in the energy range between the IR and extreme UV *** properties such as thermal conductivity,electrical conductivity,Seebeck coefficient,and thermo power factors are also calculated.

关键词： Zintl compounds TB-mBJ electronic band-structure optical properties thermoelectric properties

Characteristics of Emission Non-nulling pulsars Through Simulation

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Research in Astronomy and Astrophysics 2024年第4期24卷 91-102页

作者： rai Yuen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China SIfA School of PhysicsUniversity of SydneySydneyNSW2006Australia

We investigate the population and several properties of radio pulsars whose emission does not null(non-nulling)through simulation of a large pulsar *** from a pulsar is identified as non-nulling if(i)the emission does not cease across the whole pulse profile,and(ii)the emission is ***(i),we adopt a model for switching in the plasma charge density,and emission persists if the charge density is ***(ii),we assume that detectable emission originates from source points where it is emitted tangentially to the magnetic field-line and parallel to the *** find that pulsars exhibiting non-nulling emission possess obliquity angles with an average of 42°.5,and almost half the samples maintain a duty cycle between 0.05 and ***,the pulsar population is not fixed but dependent on the obliquity angle,with the population peaking at 20°.In addition,three evolutionary phases are identified in the pulsar population as the obliquity angle evolves,with the majority of samples having an obliquity angle between 20°and 65°.Our results also suggest that emission from a pulsar may evolve between nulling and non-nulling during its lifetime.

关键词： radiation mechanisms:non thermal stars:neutron (stars:)pulsars:general

Snapshot Survey of the presence of perfluoroalkyl Substances in products, Articles, and the Environment in Ecuador

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Engineering 2024年第6期37卷 49-61页

作者： Heidelore Fiedler Luis Vega-Bustillos Jenny Arias-pastrano Lander Vinicio pérez-Aldás Jose Castro-díaz MTM Research Centre School of Science and TechnologyÖrebro UniversityÖrebro 70182Sweden Undersecretariat of Environmental Quality Ministry of EnvironmentWater and Ecological Transition of EcuadorQuito 170525Ecuador department of Environmental Chemistry The Technical University of AmbatoHuachi CampusAmbato 180207Ecuador Alternativavision Ambiental Cia.Ltda. Mexico 03100Mexico

The Stockholm Convention on persistent Organic pollutants(pOps)is a legally binding instrument for 186 parties(status:April 2023).Accordingly,among other responsibilities,countries are obliged to report the production,import,or export of the pOps listed in Annexes A,B,or C;provide information to registers;maintain inventories;and monitor the presence of pOps in the *** the broader context of international chemicals and waste management,producer responsibilities,harmonized reporting,and compliance with national and international regulations,Ecuador has addressed the newly listed group of perfluorinated alkyl substances(pFAS)in its national implementation plan and sent selected products from its national market for pFAS *** products analyzed came from the initially listed fields of specific exemptions and acceptable purposes,including:fire-fighting foams;photographic aids;greasers/degreasers;various kinds of paper/packaging;textiles;and leather,coatings,cleaners,metal plating,and *** results showed that the three pFAS presently listed in the Stockholm Convention could be quantified in only a few samples;additional pFAS,not yet listed in the Convention also had low detection *** the number of samples was limited,the samples covered a large spectrum of sample matrices,making it possible to conclude that—once these products become waste and are regulated under the Basel Convention—they would not constitute a disposal ***,verification of the presence of pFAS in products on the market is expected to pose an analytical challenge for both,developed and developing countries.

关键词： Emerging or newly listed pOps Stockholm Convention products and articles pFAS analysis developing countries

Temperature and structure measurements of heavy-ion-heated diamond using in situ X-ray diagnostics

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Matter and Radiation at Extremes 2024年第4期9卷 80-89页

作者： J.Lutgert p.Hesselbach M.Schorner V.Bagnoud R.Belikov p.drechsel B.Heuser O.SHumphries p.Katrik B.Lindqvist C.Qu R.Redmer d.Riley G.Schaumann S.Schumacher A.Tauschwitz d.Varentsov K.Weyrich X.Yu B.Zielbauer Zs.Major p.Neumayer d.Kraus Institut fur physik Universitat RostockAlbert-Einstein-Str.2318059 RostockGermany GSI Helmholtzzentrum fur Schwerionenforschung Planckstr.164291 DarmstadtGermany Institut für Angewandte physik Goethe-Universität Frankfurt am MainMax-von-Laue-Str.160438 Frankfurt am MainGermany Institut fur Geowissenschaften Goethe-Universitat Frankfurt am MainAltenhoferallee 160438 Frankfurt am MainGermany Helmholtz-Zentrum dresden-Rossendorf Bautzner Landstr.40001328 DresdenGermany European XFEL GmbH Holzkoppel 422869 SchenefeldGermany Centre for plasma physics School of Mathematics and PhysicsQueen’s University BelfastUniversity RoadBelfast BT71NNUnited Kingdom Institut für Kernphysik Technische Universität DarmstadtSchlossgartenstr.964289 DarmstadtGermany State Key Laboratory of Nuclear physics and Technology Institute of Heavy Ion PhysicsPeking UniversityBeijing 100871China Helmholtz Institut Jena Frobelstieg 307743 JenaGermany

We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy *** this way,we determine the samples’heating dynamics and their microscopic and macroscopic structuralintegrity over a timespan of several *** the ratio of elastic to inelastic scattering with state-of-the-art density functionaltheory molecular dynamics simulations allows the inference of average temperatures around 1300 K,in agreement with predictions fromstopping power *** simultaneous diffraction measurements show no hints of any volumetric graphitization of the material,butdo indicate the onset of fracture in the diamond *** experiments pave the way for future studies at the Facility for Antiproton andIon Research,where a substantially increased intensity of the heavy ion beam will be available.

关键词： heated intense structure

paper Analytical device for the Colourimetric detection of Alkaline phosphatase in Serum and Saliva

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Journal of Analysis and Testing 2024年第03期8卷 385-394页

作者： d.Alageswari A.Lakshmidevi p.E.Resmi p.V.Suneesh Aarathipradeep T.G.SatheeshBabu department of Chemistry Amrita School of Physical Sciences Coimbatore Amrita Vishwa Vidyapeetham Amrita Biosensor Research Lab Amrita School of Engineering Coimbatore Amrita Vishwa Vidyapeetham Amrita Biomedical Engineering Centre Amrita School of Engineering Coimbatore Amrita Vishwa Vidyapeetham

A paper analytical device (pAd) was developed for the colourimetric estimation of alkaline phosphatase (ALp). ALp catalyzes the hydrolysis of disodium phenyl phosphate (dSpp) to phenol, which then undergoes oxidative coupling with4-aminoantipyrine (4-AAp) producing a reddish brown-coloured quinone imine. The colourimetric reaction tested in solution has been translated onto a pAd for the point of care (poC) testing of ALp. A uniform colour was obtained in 25 min with the introduction of ALp onto the reagent drop cast paper device. The images obtained by scanning the pAd were processed using ImageJ software. The colour intensity obtained by image processing was proportional to the concentration of ALp present in the sample. ALp in serum and saliva samples were tested using the pAd in the range of 0 to 528 U/L and0 to 187 U/L, respectively. The interference studies revealed that the pAd was selective to ALp in the presence of other biomolecules. The pAd exhibited a limit of detection (LOd) of 3.3 U/L and a sensitivity of 48.36 a.u/Log(U/L) for serum ALp and LOd of 1.69 U/L and a sensitivity of 28.5 a.u/Log (U/L) for salivary ALp. The pAd showed good agreement with the clinical methods for real samples.

关键词： Alkaline phosphatase Colourimetry ImageJ paper analytical device point of care testing

Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAd-7) functionalized with d_(2)EHpA

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Journal of Rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： p.A.Martínez-Montoya R.G.Sanchez-Alvarado d.Y.Medina-Velazquez M.L.Carrera-Jota p.Garnica-Chávez A.de J.Morales-Ramirez Higher School of Chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(d2EHpA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAd-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% d_(2)EHpA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery Rare earth solid-liquid extraction XAd-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

detailed seismic zoning of the East Kazakhstan region in the Republic of Kazakhstan

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Geodesy and Geodynamics 2024年第2期15卷 156-165页

作者： Natalya V.Silacheva N.p.Stepanenko O.K.Kurilova A.d.Kudabayeva A.T.danabayeva Institute of Seismology Ministry of Emergency SituationsAlmaty 050060Kazakhstan

Kazakhstan is currently drafting new construction regulations that comply with the major provisions of the *** regulations are created on the basis of seismic zoning maps of various degrees of detail,developed by our Institute of Seismology using a new methodological approach for *** article is about creating the first normative map of the detailed Seismic Zoning on a probabilistic foundation for the Republic of Kazakhstan’s East Kazakhstan *** carried out the probabilistic assessment of seismic hazard using a methodology consistent with the main provisions of Eurocode 8and updated compared with that used in developing maps of Kazakhstan’s General Seismic Zoning and seismic microzoning of *** most thorough and current data accessible for the area under consideration were combined with contemporary analytical *** have been done to not only the databases being used but also the way seismic sources were shown,including active faults *** a scale of 1:1000000,precise seismic zoning maps of the East Kazakhstan region were created for two probabilities of exceedance:10%and 2%in 50 years in terms of peak ground accelerations and macroseismic *** obtained seismic hazard distribution is generally consistent with the General Seismic Zoning of Kazakhstan’s previous ***,because active faults were included and a thoroughly revised catalog was used,there are more pronounced zones of increased danger along the fault in the western part of the *** the west of the territory,acceleration values also increased due to a more accurate consideration of seismotectonic *** maps are the basis for developing new state building regulations of the Republic of Kazakhstan.

关键词： probabilistic seismic hazard assessment detailed seismic zoning peak ground acceleration Microseismical intensity