Superconducting materials with high critical temperature have the potential to revolutionize many fields,including military,electronic communications,and power ***,scientists around the world have been tirelessly work...
详细信息
Superconducting materials with high critical temperature have the potential to revolutionize many fields,including military,electronic communications,and power ***,scientists around the world have been tirelessly working with the ultimate goal of achieving high-temperature *** 2023,a preprint by Lee et *** South Korea claimed the discovery of ultra-high-temperature superconductivity with a critical temperature of up to 423 K in Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037),which caused a worldwide sensation and ***,the electronic structures,phonon dynamics,and electrical conductivities of LK-99 and its parent compound lead-apatite have been calculated using first-principles *** results show that the lead-apatite compound and the LK-99 compound are insulator and half-metal *** flat band characteristic is consistent with previous *** electrical conductivity of the LK-99 compound shows two extreme points,and the electrical conductivity along the C-axis increases significantly after 400 *** phonon dispersion spectra of the compounds were investigated,demonstrating their dynamic instability.
Nucleus is essentially composed of protons and neutrons,which are commonly known as ***,some of nucleons may group together and exhibit collective behavior inside a *** clustering efects have been known since the earl...
详细信息
Nucleus is essentially composed of protons and neutrons,which are commonly known as ***,some of nucleons may group together and exhibit collective behavior inside a *** clustering efects have been known since the early stages of nuclearphysics because of the observation and description ofα-cluster decay from many heavy *** studies demonstrated that cluster structures exist in many nuclear systems,especially in weakly bound or excited states,and are complementary to the shell-like *** this review article,we provide a brief historical recall of the feld,and follow it with a conceptual and logical description of the major theoretical models that have been frequently applied in the literature to describe nuclear *** methods and progress are outlined,recent outcomes are emphasized,and perspectives relevant to future studies of heavy neutron-rich systems are discussed.
The intelligent control of accelerator particle beams,achieved through machine learning,offers a new opportunity for the design and regulation of high-power,high-intensity *** recent years,this technology has been app...
详细信息
The intelligent control of accelerator particle beams,achieved through machine learning,offers a new opportunity for the design and regulation of high-power,high-intensity *** recent years,this technology has been applied in several practical *** instance,the DeepMind team successfully used reinforcement learning to control the plasma in a Tokamak device with 19 control magnets[1].
Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the ...
详细信息
Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.
Multi-boson productions can be exploited as novel probes either for standard model precision tests or new physics searches,and have become a popular research topic in ongoing LHC experiments and future collider studie...
详细信息
Multi-boson productions can be exploited as novel probes either for standard model precision tests or new physics searches,and have become a popular research topic in ongoing LHC experiments and future collider studies,including those for electron–positron and muon–muon *** this study,we focus on two examples,i.e.,ZZZ direct productions through μ^(+)μ^(-) annihilation at a 1TeV muon collider,and ZZ productions through vector boson scattering(VBS)at a 10TeV muon collider,with an integrated luminosity of 10 ab^(-1).Various channels are considered,including ZZZ→4l2v and ZZZ→4l+*** expected significance on these multi-Z boson production processes is reported based on a detailed Monte Carlo study and signal background *** on anomalous gauge boson couplings are also presented.
The prompt fission neutron spectrum(PFNS)is a keynuclear data quantity that is of particular interest and plays a crucial role in understanding and modeling fission *** array comprising 48 liquid scintillation detect...
详细信息
The prompt fission neutron spectrum(PFNS)is a keynuclear data quantity that is of particular interest and plays a crucial role in understanding and modeling fission *** array comprising 48 liquid scintillation detectors and a parallelplate avalanche counter(PPAC)was developed at the China Institute of Atomic Energy(CIAE)to measure the PFNS of actinide *** and energy calibrations were performed for all the liquid scintillators,and their efficiencies were consistently found to be better than 5%.The time resolutions of the PPAC and liquid scintillators were measured to be 1.08 ns and 1.16 ns using~(252)Cf and~(207)Bi sources,*** pulse shape discrimination of the liquid scintillator was utilized to identify neutron andγsignals on an event-by-event basis,and the figure of merit was deduced as 1.12 at a 200 ke Vee *** contribution to the PFNS from multiple scattered neutrons was evaluated via Geant4 simulations,and those originating from the environment were found to be comparable to the crosstalk between the *** neutron efficiency of the entire detection array was calibrated using a~(252)Cf spontaneous fission source and was demonstrated to be consistent with the Geant4 simulation results,which verified the reliability of the detection array.
Hyperpolarized^(3)He nuclei have emerged as a significantly important approach in quantum precision measurement techniques,with extensive applications in fundamental physics,magnetometry,metrology,and *** this study,w...
详细信息
Hyperpolarized^(3)He nuclei have emerged as a significantly important approach in quantum precision measurement techniques,with extensive applications in fundamental physics,magnetometry,metrology,and *** this study,we report on the design and implementation of a^(3)He polarization system at the China Mianyang Research Reactor(CMRR),utilizing the metastabilityexchange optical pumping(MEOP)*** employed a Merritt coil system consisting of four square coils to furnish a uniform holding *** deployed a 2 W fiber laser to pump the metastable^(3)He atoms and conducted free induction decay(FID)detection of the polarized^(3)He nuclei using both pickup coil and optical *** the optical method,we used a50 m W linearly polarized distributed Bragg reflector(DBR)laser as the *** applied transverse light absorption polarimetry to measure the absolute nuclear polarization of the ground-state^(3)*** have developed cell fabrication capabilities at the CMRR,and cells at various pressures ranging from 100 to 1000 Pa have been fabricated and *** a typical borosilicate cell with 100 Pa pressure,the absolute polarization is measured as Pn≈70%,and the transverse relaxation time is estimated as T2≈0.5 ***,we constructed a few aluminosilicate cells,each carefully filled with pure^(3)He at a pressure of 100 ***,we conducted a comprehensive evaluation of their performance in the context of MEOP.
Kelvin's circulation,as a loop integral of the velocity field,is first shown to be equal toΓc=2πΔnΓ1+constant in an inviscid fluid,withΓ1a unit *** integerΔn is interpreted as the number of net 27r-rotations...
详细信息
Kelvin's circulation,as a loop integral of the velocity field,is first shown to be equal toΓc=2πΔnΓ1+constant in an inviscid fluid,withΓ1a unit *** integerΔn is interpreted as the number of net 27r-rotations of the velocity vector in one cyclicality along the circulation loop and hence it is a topological *** from the linkage number in the helicity invariant,which only exists in 3D space,the topological number in the circulation invariant is independent of the spatial dimension.A further study reveals that this new topological phase 2πΔn is rooted at the gauge invariance of the circulation and it is a counterpart of the Berry's phase in the quantum system.
A novel variational wave function defined as a Jastrow factor multiplying a backflow transformed Slater determinant was developed for A=3 *** Jastrow factor and backflow transformation were represented by artificial n...
详细信息
A novel variational wave function defined as a Jastrow factor multiplying a backflow transformed Slater determinant was developed for A=3 *** Jastrow factor and backflow transformation were represented by artificial neural *** this newly developed wave function,variational Monte Carlo calculations were carried out for3H and3He nuclei starting from a nuclear Hamiltonian based on the leadingorder pionless effective field *** obtained ground-state energy and charge radii were successfully benchmarked against the results of the highly-accurate hypersphericalharmonics *** backflow transformation plays a crucial role in improving the nodal surface of the Slater determinant and,thus,providing accurate ground-state energy.
The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,*** study investigates the structure and the initial ...
详细信息
The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,*** study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body Gamow coupled-channel *** results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave ***,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C ***,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of *** observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.
暂无评论