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Thermoluminescence characterization of natural and synthetic irradiated ce-monazites

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Journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.correcher c.Boronat J.garcia-Guinea J.F.Benavente T.Rivera-Montalvo cIEMAT Av.Complutense 4028040MadridSpain Mncn-cSIc J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic cePO_(4):nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,ce3+?ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODcs or nBOHcs).

关键词： Thermoluminescence Kineticparameters Phosphate ce-monazite Defects Rare earths

The effect of abiotic stresses on plant c:n:P homeostasis and their mitigation by silicon

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The crop Journal 2024年第2期12卷 340-353页

作者： Milton garcia costa Renato de Mello Prado Luiz Fabiano Palaretti Jonas Pereira de Souza Júnior Department of Agricultural Production Science School of Agricultural and Veterinarian SciencesSão Paulo State UniversityJaboticabalBrazil

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(c:n:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain c:n:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating c:n:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on c:n:P homeostasis, as well as the role of Si in preserving c:n:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining c:n:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

关键词： nutritional stoichiometry Elemental stoichiometry Beneficial element Environmental stresses nutritional efficiency carbon use efficiency Agricultural sustainability

Early Phases of Star Formation: Testing chemical Tools

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Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： n.c.Martinez S.Paron cOnIcET-Universidad de Buenos Aires.Instituto de Astronomía y Física del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

Star-forming processes strongly influence the ISM ***,many high-quality databases are available at millimeter *** them,it is possible to carry out studies that review and deepen previous *** these studies involve large samples of sources,it is preferred to use direct tools to study the molecular *** the aim of testing these tools such as the use of the Hcn/Hnc ratio as a thermometer,and the use of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H as "chemical clocks," we present a molecular line study toward 55 sources representing massive young stellar objects at different evolutionary stages:infrared dark clouds(IRDcs),highmass protostellar objects(HMPOs),hot molecular cores(HMcs) and ultracompact H II *** found that the use of the Hcn/Hnc ratio as a universal thermometer in the ISM should be taken with care because the Hcn optical depth is a big issue that can affect the ***,this tool should be utilized only after a careful analysis of the Hcn spectrum,checking that no line,neither the main nor the hyperfine ones,presents absorption *** point out that the analysis of the emission of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H could be useful to trace and distinguish regions among IRDcs,HMPOs and *** molecular line widths of these four species increase from the IRDc to the HMc stage,which can be a consequence of the gas dynamics related to the starforming processes taking place in the molecular *** results not only contribute with more statistics,acting as a probe of such chemical tools,useful to obtain information in large samples of sources,but also complement previous works through the analysis of other types of sources.

关键词： stars:formation ISM:molecules ISM:clouds

Imprints of a gravitational wave through the weak field deflection of photons

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chinese Physics c 2024年第8期48卷 240-245页

作者： Reggie c.Pantig Ali Övgün Physics Department Mapúa University658 Muralla St.IntramurosManila 1002Philippines Physics Department Eastern Mediterranean UniversityFamagusta99628 North Cyprusvia Mersin 10Turkiye

In this study,we investigate the novel phenomenon of gravitational lensing experienced by gravitational waves traveling past a Schwarzschild black hole perturbed by a specific,first-order,polar gravitational *** apply the Gauss-Bonnet theorem,finding a topological contribution to the deflection of light rays passing near the black *** demonstrate that the deflection angle can be determined by analyzing a region entirely outside the path of the light ray,leading to a calculation based solely on the parameters of the perturbing wave(Legendre polynomial order,l;frequency,σ).This approach offers a unique perspective on gravitational lensing and expands our understanding of black hole interactions with gravitational waves.

关键词： supermassive black holes gravitational waves chaos weak deflection angle Gauss-Bonnet theorem

A new strategy for corrosion protection of porous stainless steel using polypyrrole films

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Journal of Materials Science & Technology 2020年第2期37卷 85-95页

作者： c.garcia-cabezon c.garcia-Hernandez M.L.Rodriguez-Mendez F.Martin-Pedrosa Materials Engineering E.I.I.Universidad de Valladolid47011 ValladolidSpain UVASEnS E.I.I.Universidad de Valladolid47011 ValladolidSpain

In this work,a method to improve the protection against corrosion of porous sintered stainless steel is *** is based on the electrodeposition of polypyrrole(PPy)layers doped with a large size counterion such as dodecylbenzenesulphonic acid(DBSA),a conducting polymer with high corrosion resistance and good *** efficacy of PPy coating depends on the adequate adhesion between the metal substrate and the coating *** protection against corrosion has been tested using 316 L stainless steel(SS)powder sintered at different conditions to evaluate the effect of the sintering atmosphere(nitrogen and vacuum)and cooling rates(furnace and water)on corrosion resistance,while wrought 316 L SS has been used as reference *** addition,two electrochemical deposition techniques have been tested to select the most *** circuit potential evolution,anodic polarization measurements and electrochemical impedance spectra have been used to evaluate corrosion protection in phosphate buffer saline *** has been evidenced that a more homogeneous and stable coating was obtained in the case of porous stainless *** corrosion potential shifted to nobler values and the anodic polarization branch became more *** porous samples have a good passivation performance with a lower stable passive current density and a higher breakdown *** transfer electronic resistance and the impedance module increase more than one order of ***,the porosity of sintered stainless steel is seen as an advantage for the improvement of the adherence of the PPy *** best corrosion protection is found for samples sintered in nitrogen and water-cooled.

关键词： Stainless steel Powder metallurgy Protection corrosion Electrodeposited films Polymer coatings

Breaking paradigms: Long non-coding RnAs forming gene fusions with potential implications in cancer

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Genes & Diseases 2024年第3期11卷 311-323页

作者： David Sanchez-Marin Macrina Beatriz Silva-cazares Fany Iris Porras-Reyes Rebeca garcia-Roman Alma D.campos-Parra Posgrado en ciencias Biologicas Facultad de MedicinaUniversidad Nacional Autonoma de MexicoCiudad de MexicoC.P.04360Mexico Unidad Academica Multidisciplinaria Region Altiplano Universidad Autonoma de San Luis Potost(UASLP)Carretera a Cedral Km 5+600Ejido San Jose de la TrojesMatehualaSan Luis PotosiC.P.78760Mexico Servicio de Anatomia Patologica Instituto Nacional de Cancerologia(INCan)Nino JesuisTlalpanCiudaddeMexicoC.P.14080Mexico Instituto de Salud Publica Universidad Veracruzana(UV)Av.Dr LuisDr.Castelazo Ayala s/nCol.Industrial AnimasXalapaVeracruzC.P.91190Mexico

Long non-coding RnAs(lncRnAs)are non-coding RnAs longer than 200 nucleotides with dynamic regulatory *** interact with a wide range of molecules such as DnA,RnA,and proteins to modulate diverse cellular functions through several mechanisms and,if deregulated,they can lead to cancer development and ***,it has been described that IncRnAs are susceptible to form gene fusions with mRnAs or other IncRnAs,breaking the paradigm of gene fusions consisting mainly of protein-coding ***,their biological significance in the tumor phenotype is still ***,their recent identification opens a new line of research to study their biological role in tumor-igenesis,and their potential as biomarkers with clinical relevance or as therapeutic *** present study aimed to review the IncRnA fusions identified so far and to know which of them have been associated with a potential *** address the current challenges to deepen their study as well as the reasons why they represent a future therapeutic window incancer.

关键词： cancer Genefusions IncRnAs ncRnAs Therapy

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： n.IQBAL J.cHOI S.F.SHAH c.LEE S.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline ni-rich LinixMnyco_(z)O_(2)(x≥0.8)(nMc)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary nMc particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of nMc active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation ni-rich LinixMnyco_(z)O_(2)(x>0.8)(nMc)

Empirical model for fusion cross sections of ca-induced reactions

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chinese Physics c 2024年第3期48卷 126-132页

作者： Reddi Rani.L n.Sowmya K.n Sridhar H c.Manjunatha M.M.Armstrong Arasu Department of Physics St.Joseph's College(Autonomous)Affiliated to Bharathidasan UniversityTiruchirappalli620002TNIndia Department of Physics Govt.First.Grade CollegeChikkaballapur-562101KarnatakaIndia Department of Physics Govt.First.Grade CollegeMalur-563160KarnatakaIndia Department of Physics Govt.First.Grade CollegeDevanahalli-562110KarnatakaIndia

A new empirical formula for the astrophysical S-factor has been suggested as a function of the coulomb interaction parameter,center of mass energy,and barrier *** 22 fusion reactions with ^(40,48)ca as projectiles were considered for different targets,leading to compound nuclei with atomic and mass numbers varying between 40≤Z≤≤Z≤112 and 88≤A≤27888≤A≤278,*** fusion cross-sections have been estimated using the geometric factor,the Gamow-Sommerfield factor,and the empirical formula for the *** study's findings showed better agreement with those of available experiments when compared to Wong's *** present work leads to a smaller standard deviation value than Wong's formula when used to correlate the experimental data of calcium-induced fusion ***'s formula provides a good approximation of fusion cross-sections when the center of mass energy is below the fusion barrier when compared to above the fusion barrier.

关键词： fusion cross-sections Wong formula Gamow-Sommerfield-factor Geometric-factor S-factor

Important step towards an understanding of the exotic Z_(c)(3900)

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Science china(Physics,Mechanics & Astronomy) 2024年第9期67卷 199-200页

作者： c.Hanhart Institute for Advanced Simulation Forschungszentrum JulichJilich D-52425Germany

The Standard Model of particle physics,which contains the field theories for the electro-weak interaction(QED)and the strong interaction(QcD),is an extremely successful theory describing a huge variety of phenomena at... 详细信息

关键词： interaction atomic describing