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Probing turbulence in galaxies with fast radio burst scintillation

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Science China(Physics,mechanics & Astronomy) 2024年第1期67卷 177-178页

作者： James m.Cordes Department of Astronomy the Cornell Center for Astrophysics and Planetary ScienceCornell UniversityIthaca NY 14853USA

Interstellar scintillation(ISS)is a well-known phenomenon observed from pulsars in the milky *** comprises intensity variations *** and frequency caused by constructive and destructive interference from multipath propagation,which is due to diffraction from fluctuations in electron density in the interstellar medium(ISm)on scales as small as~100 *** density fluctuations appear to be part of a turbulence process combined with discrete structures in electron density from other astrophysical processes;together these fluctuations extend to scales of pc or larger.

关键词： scales galaxies turbulence

Pair of dyon production near magnetized dyonic Reissner-Nordstrom black holes

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Chinese Physics C 2024年第5期48卷 257-271页

作者： Haryanto m.Siahaan Jurusan Fisika Universitas Katolik ParahyanganJalan Ciumbuleuit 94Bandung 40141Indonesia

We investigate the phenomenon of pair production of massive scalar particles with magnetic charge near the horizon of a magnetized dyonic Reissner-Nordstrom black *** intrinsic symmetry between the electric and magnetic quantities in the Einstein-maxwell equations suggests that the pair can be generated through Hawking radiation and the Schwinger effect,provided that the Dirac quantization condition is satisfied.

关键词： Dyon pair production black hole

On calculating glacial isostatic adjustment

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Geodesy and Geodynamics 2024年第5期15卷 441-452页

作者： L.m.Cathles Cornell University IthacaNY 14853USA

modeling the earth's fluid and elastic response to the melting of the glaciers of the last ice age is the most direct way to infer the earth's radial viscosity ***,we compare two methods for calculating the viscoelastic response to surface *** one,the elastic equation of motion is converted to a viscoelastic equation using the Correspondence *** the other,elastic deformation is added to the viscous flow as isostatic adjustment *** two modeling methods predict adjustment histories that are different enough to potentially impact the interpretation of the observed glacial isostatic adjustment(GIA).The differences arise from buoyancy and whether fluid displacements are subjected to hydrostatic *** methods agree if they use the same equations and boundary *** origin of the differences is determined by varying the boundary conditions and pre-stress application.

关键词： Glacial isostatic adjustment Viscoelastic normal modes Hydrostatic pre-stress Elastic buoyancy Correspondence principle

Consumer transparency in the production chain for plant varieties produced using new genomic techniques

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aBIOTECH 2024年第2期5卷 239-246页

作者： J.m.Lukasiewicz C.C.m.van de Wiel L.A.P.Lotz m.J.m.Smulders Wageningen University&Research P.O.Box 386NL-6700 AJ WageningenThe Netherlands

Plants edited with new genomic techniques(NGTs)currently fall under the Genetically modified Organisms Directive(2001/18/EC)in the European *** the proposal of the European Commission,NGT plants are partially exempted from the regulations of this *** proposal makes a distinction between two categories of NGT plants:NGT-1 and ***-1 category plants are considered equal to plants obtained through conventional breeding *** plants will not be labelled for the consumer,although they will be labelled as ***-2 category plants may be labelled with additional information as a positive *** of seeds of varieties made with gene editing,but not the products,would mean that most steps in the production chain are transparent,but not the last step towards ***“right to know”and increasing knowledge of gene-edited food is a common theme in food labelling towards ***,we describe current labelling regimes and registers and how these may be applied to provide transparency on gene-edited products to ***,we also look into consumer studies,which indicate a greater acceptance of gene-edited food among consumers,especially when additional benefits such as sustainability are mentioned.

关键词： Labelling New genomic techniques Consumer transparency Plant products

QCD sum rule study of J^(P)=1^(±)exotic states with two heavy quarks in the molecular picture

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Chinese Physics C 2024年第6期48卷 31-37页

作者： T.m.Aliev S.Bilmis m.Savcı Department of Physics Middle East Technical UniversityAnkara06800Turkey TUBITAK ULAKBIm Ankara06510Turkey

In this study,the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks(scalar-axial and pseudoscalar-axial meson combinations)are investigated within the QCD sum *** findings reveal that molecular states containing charm quarks do not form bound states,whereas states with b-quarks can form exotic molecular *** observation has significant implications for understanding the structure of these exotic states.

关键词： QCD sum rules exotic mesons molecular states

Analysis of strong decays of SU(3)partners ofΩ(2012)baryon

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Chinese Physics C 2024年第8期48卷 34-41页

作者： T.m.Aliev S.Bilmis m.Savci Department of Physics Middle East Technical UniversityAnkara 06800Turkey TUBITAK ULAKBIm Ankara 06510Turkey

We estimate the coupling constants and decay widths of the SU(3)partners of theΩ(2012)hyperon,as discovered by the BELLE Collaboration,using the distribution amplitudes of the octet baryons within the light cone sum rules *** study includes a comparison of the obtained results for the relevant decay widths with those derived within the framework of the flavor SU(3)*** observe a good agreement between the predictions of both ***,our result on the decay width ofΩ→ΞK is compatible with the existing experimental result within the uncertainties of the model *** results can provide helpful insights for determining the nature of the SU(3)partners of theΩ(2012)baryon.

关键词： coupling constants light cone sum rule hyperon

System Design for the Event Horizon Imaging Experiment Using the PECmEO Concept

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空间科学学报 2019年第2期39卷 250-266页

作者： KUDRIASHOV Volodymyr martin-neira manuel BARAT Itziar martin IGLESIAS Pertonilo DAGANZO-EUSEBIO Elena ALAGHA Nader VALENTA Vaclav European Space Research and Technology Centre the European Space Agency

The concept for space interferometry from Polar or Equatorial Circular medium Earth Orbits(the PECmEO concept) is a promising way to acquire the image of the"shadow"of the event horizon of Sagittarius A*with an angular resolution of circa 5 microarcseconds. The concept is intended to decrease the size of the main reflector of the instrument to about 3 m using a precise orbit reconstruction based on Global Navigation Satellite System (GNSS) navigation, inter-satellite range and range-rate measurements, and data from the Attitude and Orbit Determination System (AODS). The paper provides the current progress on the definition of the subsystems required for the concept on the basis of simulations, radio regulations, and available technology. The paper proposes the requirement for the localization of the phase centre of the main reflector. The paper provides information about the visibility of GNSS satellites and the needed accuracies of the AODS. The paper proposes the frequency plan for the instrument and its Inter-Satellite Links (ISLs).The concepts for measurement of range and range-rate using ISLs (as well as for the data exchange at these ISLs) are presented. The block diagram of the interferometer is described and its sensitivity is estimated. The link budget for both ISLs is given as well as their critical components. The calculated measurement quality factors are given. The paper shows the expected performance of the sub-systems of the interferometer. The requirements for the localization of the main reflectors and the information about the availability of the GNSS satellites are based on the simulations results. The frequency plan is obtained according to the PECmEO concept and taking into account the radio regulations. The existing technology defines the accuracies of the AODS, both the link budgets and the fundamental measurement accuracies for ISLs, and the sensitivity of the instrument. The paper provides input information for the development of the orbit r

关键词： Instrumentation Telescope High angular resolution Interferometer Space VLBI

Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 359-376页

作者： Praveen Huded m Suresh R Dash LEA Associates South East Asia Pvt.Ltd. New Delhi 110044India Indian Institute of Technology Bhubaneswar Khurda 752050India

Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone *** foundations have experienced failures in past earthquakes due to *** on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil ***,in natural occurrence,it may occur in alternative layers of liquefiable and non-liquefiable ***,the experimental and/or numerical studies on the layered effect on pile foundations have not been widely addressed in the *** of the design codes across the world do not explicitly mention the effect of sandwiched non-liquefiable soil layers on the pile *** the present study,the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied *** study found that the kinematic bending moment is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ***,ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach.

关键词： pile foundation liquefaction alternately layered soil fixity effect layered effect

magnetic,dielectric and electrical modulus of Ce^(3+) doped cobalt-magnesium ferrite nanoparticles

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Journal of Rare Earths 2024年第2期42卷 373-382,I0005页

作者： N.m.Basfer Hanaa Almaghamsi Department of Physics Umm AL-Qura UniversityMakkahSaudi Arabia Physics Department College of Science and ArtKing Abdulaziz UniversityPOB344Rabigh291Saudi Arabi

In this work,the magnetic,dielectric properties and electric modulus of Ce^(3+) substituted cobaltmagnesium(Co_(0.7)mg_(0.3)Ce_(x)Fe_(2-x)O_4)(labeled as CmCF) ferrite nanoparticles were investigated in *** magnetization decreases from 50.05 to 34.87 emu/g for further substituting Ce^(3+) ***,coercivity increases from 738.22 Gs for the CmCFO sample to 912.10 Gs for the CmCF2 sample,then decreases monotonically to 762.1 Gs for the CmCF5 *** cerium content and particle size play important roles in controlling the magnetization and coercivity of the CmCF *** CmCF nanoferrites are suitable for microwave applications since their high-frequency response ranges from 7.72 to 11.07 *** CmCF nanoferrites' dielectric parameter dispersion exhibits normal *** pristine Co-mg nanoferrite only has ε' value of 28.25,but the nanoferrite mCmF2 has ε' value of365.03,with an enhancing ratio of 1192%.The conduction mechanism of the mCmF nanoferrites was determined by fitting the σ_(ac) results via the Jonscher power *** 653 K,large polaron tunnelling is thought to be responsible for this conduction process,which is followed by electron barrier hopping at higher ***-Cole diagrams at different temperatures,assuring the contributions of the grains and their boundaries at lower temperatures(653 K) and only the grains at higher *** on our results,the CmCF nanoferrites hold magnetic and semiconducting nature,which can be used in magnetic devices and dielectrics in lower-frequencies or conductors in higher-frequencies.

关键词： Nanoferrites Rare earth ions magnetic properties Dielectric parameters Impedance spectroscopy