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Analytical description of shape transition in nuclear alternating parity bands

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Chinese Physics C 2018年第12期42卷 112-122页

作者： E.V.mardyban t.m.shneidman E.A.Kolganova R.V.Jolos 周善贵 Bogoliubov Laboratory of theoretical Physics Joint Institute for Nuclear Research Dubna State University Kazan Federal University CAS Key Laboratory of theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences Center of theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Synergetic Innovation Center for Quantum Effects and Application Hunan Normal University

the angular momentum dependencies parity bands of heavy nuclei have been analyzed of parity splitting and electric dipole transitions in the alternating It is shown that these dependencies can be treated in a universal manner with a single critical angular momentum parameter, which characterizes phase transition from octupole vibrations to the stable octupole deformation. Using the simple but useful model of axially-symmetric reflection- asymmetric mode, the analytical expressions for parity splitting and electric dipole transitional moment have been obtained. the findings are in good agreement with the experimental data for various isotopes of Ra, th, U, and Pu.

关键词： octupole deformation phase transition angular momentum

Angular Anisotropy of the Fission Fragments in the Dinuclear System model

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原子核物理评论 2015年第2期32卷 175-179页

作者： t.m.shneidman A.V.Andreev C.massimi m.t.Pigni G.Vannini A.Ventura 周善贵 Joint Institute for Nuclear Research Institute of theoretical Physics Chinese Academy of Sciences Kazan Federal University Istituto Nazionale di Fisica Nucleare Sezione di Bologna Dipartimento di Fisica dell Universit`a di Bologna Nuclear Data Criticality Safety Oak Ridge National Laboratory

A theoretical evaluation of the collective excitation spectra of nucleus at large deformations is possible within the framework of the dinuclear system(DNS) model, which treats the wave function of the fissioning nucleus as a superposition of a mononucleus configuration and two-cluster configurations in a dynamical way, permitting exchange of nucleons between clusters. In this work the method of calculation of the potential energy and the collective spectrum of fissioning nucleus at scission point is presented. Combining the DNS model calculations and the statistical model of fission we calculate the angular distribution of fission fragments for the neutron–induced fission of239 Pu.

关键词： cluster states in nuclei dinuclear system fission angular anisotropy

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

Distribution, health and ecological risk assessments of trace elements in Nigerian oil sands

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维普期刊数据库

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Acta Geochimica 2024年第1期43卷 59-71页

作者： Odunayo t.Ore Festus m.Adebiyi Department of Chemistry Obafemi Awolowo UniversityIle-Ife 220005Nigeria Department of Chemical Sciences Achievers UniversityOwoNigeria

the Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. In the present study, we investigated the distribution pattern of 18trace elements(including biophile and chalcophile elements) as well as the estimated risks associated with exposure to these elements. the results of the study indicated that Fe was the most abundant element, with a mean concentration of 22,131 mg/kg while Br had the lowest mean concentration of 48 mg/kg. the high occurrence of Fe and ti suggested a possible occurrence of ilmenite(Fe tiO_(3)) in the oil sands. Source apportionment using positive matrix factorization showed that the possible sources of detected elements in the oil sands were geogenic, metal production, and crustal. the contamination factor, geo-accumulation index, modified degree of contamination, pollution load index, and Nemerow pollution index indicated that the oil sands are heavily polluted by the elements. Health risk assessment showed that children were relatively more susceptible to the potentially toxic elements in the oil sands principally via ingestion exposure route(HQ > 1E-04). Cancer risks from inhalation are unlikely due to CR t ingestion and dermal contact pose severe risks(CR > 1E-04). the high concentrations of the elements pose serious threats due to the potential for atmospheric transport, bioaccessibility, and bioavailability.

关键词： Biophile Chalcophile Oil sand Risk assessment trace element

tensile deformation of fine-grained mg at 4K,78K and 298K

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Journal of magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula P.Noga t.tokarski G.Cios m.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland materials Science and Engineering McMaster UniversityHamiltonCanada

the impact of grain size,ranging from 0.9μm to 9μm,on the mechanical properties of commercially pure mg is investigated at temperatures of 4K,78K,and *** mechanisms governing plastic flow are influenced by both grain size and *** 4K and 78K,dominant deformation modes in mg involve dislocation glide and extension twinning,regardless of grain *** interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime,leading to premature *** yield stress follows the Hall-Petch relationshipσ_(y)∼k/√d,with the slope k increasing with decreasing *** 298K,in addition to dislocation glide and twinning,grain boundary sliding(GBS)becomes significant in samples with grain sizes below 3μm,considerably enhancing the material’s *** activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries,facilitating their absorption during sliding and *** ofσrelationship suggests that the basal slip is the dominant dislocation mode in mg at *** grain size suppresses dislocation activity and twinning and increases GBS,resulting in lowerandσ*** conventional deformation modes coupled with enhanced GBS yields stress softening,breaking down the Hall-Petch relationship in mg below 3μm grain size,leading to an inverse Hall-Petch *** work reports new data on the strength,ductility,work hardening and fracture behaviour,and their variations with mg grain size across different temperature regimes.

关键词： Polycrystalline mg mechanical properties Deformation mechanisms Work-hardening texture evolution Cryogenic temperatures Hall-Petch relationship

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

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Applied mathematics and mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE m.t.mUNIR G.J.WENG K.Y.RHEE Biomaterials and tissue Engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and technology American University of the Middle EastEgaila 54200Kuwait Department of mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

Search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 teV using CmS open data

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Chinese Physics C 2024年第4期48卷 6-13页

作者： Y.mahmoud H.Abdallah m.t.Hussein S.Elgammal Centre for theoretical physics The British University in EgyptEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

In this study,we conducted a search for dark matter using a part of the data recorded by the CmS experiment during run-I of the LHC in 2012 with a center of mass energy of 8 teV and an integrated luminosity of 11.6 fb−*** data were gathered from the CmS open *** matter,in the framework of the simplified model(mono-Z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,Z′.thus,the search was conducted in the dimuon plus large missing transverse momentum *** benchmark scenario of mono-Z′,which is known as light vector,was used for interpreting the CmS open *** evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and Z′at 95%confidence level.

关键词： dark matter large hadron collider CmS open data search for new physics dark fermion

Aerodynamics of a tandem-Bladed Axial Compressor Rotor under Circumferential Distortion at Different Rotational Speeds

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Journal of thermal Science 2024年第4期33卷 1340-1356页

作者： Amit KUmAR Jerry t.JOHN A.m.PRADEEP R.A.DAKKERmANS Dragan KOZULOVIC Department of Aerospace Engineering Indian Institute of Technology BombayMumbai400076India Department of Automotive and Aeronautical Engineering Hamburg University of Applied Sciences20099HamburgGermany Institute of Jet Propulsion Bundeswehr University Munich85577NeubibergGermany

For most aircraft engines,inflow distortion is *** distortion is known to degrade the aerodynamic performance and stable operating limits of a *** rotor configuration is an arrangement that effectively controls the growth of the boundary layer over the suction surface of the ***,a higher total pressure rise can be achieved through this unconventional design approach involving the splitting of the blade into forward and aft *** is expected that the effect of inlet flow distortion would be more severe for a tandem-rotor design due to the greater flow turning inherent in such ***,this aspect needs to be thoroughly *** present study discusses the effect of circumferential distortion on the tandem-rotor at different rotational ***-annulus RANS simulations using ANSYS CFX are used in the present *** performance of the rotor at a particular flow coefficient and different rotational speeds is *** total pressure and efficiency are observed to drop at lower mass flow rates under the influence of circumferential *** loss region in each blade passage is mainly associated with the blade wake,tip leakage vortex,secondary flow,and boundary ***,their contribution varies from passage to passage,particularly in the distorted *** the lower span,the wake width is found to be higher than that at a higher *** to the redistribution of the mass flow,the circumferential extent reduces at a higher *** the undistorted sector,the strength of the tip leakage vortex is significantly higher at the design rotational speed than at lower *** distortion near the tip region promotes an early vortex breakdown even at the design operating *** adversely affects the total pressure,efficiency,and stall *** clean flow conditions,this phenomenon is only observed near the stall *** the design operating condition,the breakdown of the forward rotor tip l

关键词： tandem rotor circumferential distortion loss tip leakage vortex vortex breakdown diffusion factor aerodynamics of compressor blade