In recent years,neutrino-nucleus scattering has been extensively researched to investigate nuclear structures and interactions between neutrinos and nucleons.In this study,a charged-current quasielastic(CCQE)neutrino-...In recent years,neutrino-nucleus scattering has been extensively researched to investigate nuclear structures and interactions between neutrinos and nucleons.In this study,a charged-current quasielastic(CCQE)neutrino-nucleus scattering model is developed to explore the nuclear mean-field dynamics and short-range correlation effects.In this model,the effect of the nuclear structure is depicted using the scaling function f(ψ),whereas the neutrino-nucleon interaction is represented by the elementary weak cross sectionσ_(0).The results indicate that the double-differential cross section of the scattered muon is influenced by the energy E and mo mentum p of the nucleon in the nuclei,and the total cross section depends primarily on the incident neutrino energy E_(ν).Furthermore,incorporating short-range correlations results in the flux-integrated differential cross sections in the high-T_(μ)region producing larger values,a longer tail,and achieving better experimental consistency.It eventually elucidates the physical relationship between the neutrino-nucleus scattering cross section and variation in the incident neutrino energy.This paper shares insights for the research on nucleon dynamics and presents detailed investigations of the neutrino-nucleus scattering mechanism.展开更多
Here we present the polymerization of n-butyl acrylate (BA), ethyl acrylate (EA) and methyl acrylate (MA) in tri-component microemulsions, using a cationic surfactant such as dodecyl trimetyl ammonium bromide in water...Here we present the polymerization of n-butyl acrylate (BA), ethyl acrylate (EA) and methyl acrylate (MA) in tri-component microemulsions, using a cationic surfactant such as dodecyl trimetyl ammonium bromide in water, as a function of temperature, initiator type and, monomer and initiator concentration. The final latexes are transparent and blue color, with particle size ranging between 20 and 60 nm determined by quasielastic light scattering (QLD) and SEC molar masses of the order of 106 g/mol. Reaction times are short and reaction rates are high with final conversions between 70 and 98% depending on the monomer and the reaction conditions.展开更多
Neutron diffraction studies of the low-temperature relaxor ferroelectric phases of[NH_(4)^(+)]M(HCO_(2))_(3),where M=Mn^(2+)and Zn^(2+),show that a third of the NH_(4)^(+)t cations remain subtly structurally disordere...Neutron diffraction studies of the low-temperature relaxor ferroelectric phases of[NH_(4)^(+)]M(HCO_(2))_(3),where M=Mn^(2+)and Zn^(2+),show that a third of the NH_(4)^(+)t cations remain subtly structurally disordered to low temperature.All NH_(4)^(+) cations within the channels are well separated from each other,with significant hydrogen bonds only with the anionic M(HCO_(2))_(3) framework.Complementary studies of the dynamics using ^(2)H solid state NMR and quasielastic neutron scattering indicate significant rotational motion in both paraelectric and ferroelectric phases,which evolves gradually with increasing temperature with no abrupt change at the phase transition.Nudged elastic band calculations suggest that the activation barrier for flipping between"up"and"down"orientations of the NH_(4)^(+) cations is low in the ferroelectric phase,with the NH_(4)^(+) cations primarily interacting with the framework rather than neighbouring NH_(4)^(+)*cations.It is likely this motion that is responsible for scrambling the NH_(4)^(+) cation orientation locally in the ferroelectric phase.We propose that this disorder,with the same basic motion active above and below the phase transition,induces the significant dielectric relaxation in these materials.This suggests that orientational disorder may be an effective substitution for compositional disorder commonly associated with relaxor ferroelectrics in molecular materials.展开更多
The dynamics of methanol within prototype methanol synthesis catalysts were studied using quasi-elastic neutron scattering.Three Cu-exchanged zeolites(mordenite,SSZ-13 and ZSM-5)were studied after methanol loading and...The dynamics of methanol within prototype methanol synthesis catalysts were studied using quasi-elastic neutron scattering.Three Cu-exchanged zeolites(mordenite,SSZ-13 and ZSM-5)were studied after methanol loading and showed jump diffusion coefficients between 1.04×10^(−10)and 2.59×10^(−10)m^(2)·s^(-1).Non-Arrhenius behavior was observed with varying temperature due to methoxy formation at Brønsted acid sites and methanol clustering around copper cations.展开更多
Nucleon properties and structure should be modified by short-range correlations(SRC)among nucleons.By analyzing SRC ratio data,we extract the mass of a nucleon in an SRC pair and the expected number of pn-SRC pairs in...Nucleon properties and structure should be modified by short-range correlations(SRC)among nucleons.By analyzing SRC ratio data,we extract the mass of a nucleon in an SRC pair and the expected number of pn-SRC pairs in deuterium,under the assumption that the SRC nucleon mass is universal for different nuclei.The nucleon mass of a two-nucleon SRC pair is m_(SRC)=852±18 MeV,and the number of pn-SRC pairs in deuterium is n^(d)_(SRC)=0.021±0.005.The mass deficit of the strongly overlapping nucleon can be explained by the trace anomaly contribution to the mass in QCD or alternatively by the vacuum energy in the MIT bag model.展开更多
基金supported by the National Natural Science Foundation of China(12475135,12035011)by the Shandong Provincial Natural Science Foundation,China(ZR2020MA096)by the Fundamental Research Funds for the Central Universities(22CX03017A)。
文摘In recent years,neutrino-nucleus scattering has been extensively researched to investigate nuclear structures and interactions between neutrinos and nucleons.In this study,a charged-current quasielastic(CCQE)neutrino-nucleus scattering model is developed to explore the nuclear mean-field dynamics and short-range correlation effects.In this model,the effect of the nuclear structure is depicted using the scaling function f(ψ),whereas the neutrino-nucleon interaction is represented by the elementary weak cross sectionσ_(0).The results indicate that the double-differential cross section of the scattered muon is influenced by the energy E and mo mentum p of the nucleon in the nuclei,and the total cross section depends primarily on the incident neutrino energy E_(ν).Furthermore,incorporating short-range correlations results in the flux-integrated differential cross sections in the high-T_(μ)region producing larger values,a longer tail,and achieving better experimental consistency.It eventually elucidates the physical relationship between the neutrino-nucleus scattering cross section and variation in the incident neutrino energy.This paper shares insights for the research on nucleon dynamics and presents detailed investigations of the neutrino-nucleus scattering mechanism.
文摘Here we present the polymerization of n-butyl acrylate (BA), ethyl acrylate (EA) and methyl acrylate (MA) in tri-component microemulsions, using a cationic surfactant such as dodecyl trimetyl ammonium bromide in water, as a function of temperature, initiator type and, monomer and initiator concentration. The final latexes are transparent and blue color, with particle size ranging between 20 and 60 nm determined by quasielastic light scattering (QLD) and SEC molar masses of the order of 106 g/mol. Reaction times are short and reaction rates are high with final conversions between 70 and 98% depending on the monomer and the reaction conditions.
基金supported during this work through a Project Grant from the Leverhulme Trust(RPG-2018-288)Neutron diffraction and QENS experiments at the ISiS Pulsed Neutron and Muon Source were supported by a beamtime allocation from the Science and Technology Facilities Council(RB 1820062 and 1910402)We are grateful to the UK Materials and Molecular Modelling Hub for computational resources,which is partially fundedby EPSRC(EP/T022213/1,EP/W032260/1 and EP/P020194/1).
文摘Neutron diffraction studies of the low-temperature relaxor ferroelectric phases of[NH_(4)^(+)]M(HCO_(2))_(3),where M=Mn^(2+)and Zn^(2+),show that a third of the NH_(4)^(+)t cations remain subtly structurally disordered to low temperature.All NH_(4)^(+) cations within the channels are well separated from each other,with significant hydrogen bonds only with the anionic M(HCO_(2))_(3) framework.Complementary studies of the dynamics using ^(2)H solid state NMR and quasielastic neutron scattering indicate significant rotational motion in both paraelectric and ferroelectric phases,which evolves gradually with increasing temperature with no abrupt change at the phase transition.Nudged elastic band calculations suggest that the activation barrier for flipping between"up"and"down"orientations of the NH_(4)^(+) cations is low in the ferroelectric phase,with the NH_(4)^(+) cations primarily interacting with the framework rather than neighbouring NH_(4)^(+)*cations.It is likely this motion that is responsible for scrambling the NH_(4)^(+) cation orientation locally in the ferroelectric phase.We propose that this disorder,with the same basic motion active above and below the phase transition,induces the significant dielectric relaxation in these materials.This suggests that orientational disorder may be an effective substitution for compositional disorder commonly associated with relaxor ferroelectrics in molecular materials.
基金the support of the Australian Centre for Neutron Scattering,ANSTO and the Australian Government through the National Collaborative Research Infrastructure Strategy,in supporting the neutron research infrastructure used in this work via ACNS proposal P13488The ISIS neutron and Muon source also awarded a grant of beamtime(RB2220457).
文摘The dynamics of methanol within prototype methanol synthesis catalysts were studied using quasi-elastic neutron scattering.Three Cu-exchanged zeolites(mordenite,SSZ-13 and ZSM-5)were studied after methanol loading and showed jump diffusion coefficients between 1.04×10^(−10)and 2.59×10^(−10)m^(2)·s^(-1).Non-Arrhenius behavior was observed with varying temperature due to methoxy formation at Brønsted acid sites and methanol clustering around copper cations.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030301)the National Science Foundation China(11305007)。
文摘Nucleon properties and structure should be modified by short-range correlations(SRC)among nucleons.By analyzing SRC ratio data,we extract the mass of a nucleon in an SRC pair and the expected number of pn-SRC pairs in deuterium,under the assumption that the SRC nucleon mass is universal for different nuclei.The nucleon mass of a two-nucleon SRC pair is m_(SRC)=852±18 MeV,and the number of pn-SRC pairs in deuterium is n^(d)_(SRC)=0.021±0.005.The mass deficit of the strongly overlapping nucleon can be explained by the trace anomaly contribution to the mass in QCD or alternatively by the vacuum energy in the MIT bag model.
