Using core-scattered closed-orbit theory and region-splitting iterative method, we calculated the scaled recurrence spectra of helium atom in parallel electric and magnetic fields. Closed orbits in the corresponding c...Using core-scattered closed-orbit theory and region-splitting iterative method, we calculated the scaled recurrence spectra of helium atom in parallel electric and magnetic fields. Closed orbits in the corresponding classical system have also been obtained. When we search the closed orbits, in order to remove the Coulomb singularity of the classical Hamiltonian motion equations, we implement the Kustaanheimo-Stiefel transformation, which transforms the system from a three-dimensional to a four-dimensional one. The Fourier transformed spectrum of helium atom has allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The results are compared with those of the hydrogen case, which shows that the core-scattered effects play an important role in the recurrence spectra of the multi-electron Rydberg atom.展开更多
Ovarian tumor may occur in women ofany age, but mostly seen in women duringtheir child-bearing period. The disease shouldbe treated mainly by surgical operation,supplemented by radiotherapy and chemo-therapy. However,...Ovarian tumor may occur in women ofany age, but mostly seen in women duringtheir child-bearing period. The disease shouldbe treated mainly by surgical operation,supplemented by radiotherapy and chemo-therapy. However, the above therapies maycause a series of toxic side-effects, such asalopecia, diarrhea, edema, anorexia, nausea,dry mouth, spontaneous perspiration, headache,展开更多
During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the fiel...During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the field of neutron interferometry and ultra-small angle neutron scattering as well as in the field of radiochemistry, education and training and research in the field of nuclear safeguards and nuclear security. Potential further directions of research are outlined where the Atominstitut of Vienna might concentrate in future.展开更多
The China Spallation Neutron Source(CSNS)is the first accelerator-based multidiscipline user facility to produce pulsed neutrons by tungsten target under collision of a pulsed proton beam with a beam power of 100 kW a...The China Spallation Neutron Source(CSNS)is the first accelerator-based multidiscipline user facility to produce pulsed neutrons by tungsten target under collision of a pulsed proton beam with a beam power of 100 kW at a repetition rate of 25 Hz.In this paper,we focus on the physical design of CSNS target station and neutron instruments.Under optimized design,the flat tungsten target and the compact target-moderator-reflector coupling enhance effective cold and thermal neutron output from moderators.Three wing-type moderators supply four different characteristics of neutrons to 19 beamlines primarily for neutron scattering applications.Layout of neutron instruments are conceptually planned for total 20 beamlines,the configuration and specification have been determined for three day-one neutron instruments.All designs are optimized for the Phase I of 100 kW with a upgradable capacity to 500 kW.展开更多
We report thermodynamic and neutron scattering measurements of the triangular-lattice quantum Ising magnet TmMgGaO_(4)in longitudinal magnetic fields.Our experiments reveal a quasi-plateau state induced by quantum flu...We report thermodynamic and neutron scattering measurements of the triangular-lattice quantum Ising magnet TmMgGaO_(4)in longitudinal magnetic fields.Our experiments reveal a quasi-plateau state induced by quantum fluctuations.This state exhibits an unconventional non-monotonic field and temperature dependence of the magnetic order and excitation gap.In the high field regime where the quantum fluctuations are largely suppressed,we observed a disordered state with coherent magnon-like excitations despite the suppression of the spin excitation intensity.Through detailed semi-classical calculations,we are able to understand these behaviors quantitatively from the subtle competition between quantum fluctuations and frustrated Ising interactions.展开更多
We present an analysis of π-^20Ne elastic scattering at intermediate energy basing on the α＋^16O model of the ^20Ne nucleus and in the framework of Glauber multiple scattering theory. Satisfactory agreement with th...We present an analysis of π-^20Ne elastic scattering at intermediate energy basing on the α＋^16O model of the ^20Ne nucleus and in the framework of Glauber multiple scattering theory. Satisfactory agreement with the general features of the experimental data of pion elastic scattering on the neighboring 4N-type nuclei is obtained without any free parameters. Compared with the experimental angular distributions of pion elastic scattering on ^12 C, ^16O, ^24Mg, and ^28Si nuclei, the diffractive patterns and the positions of the dips and peaks in the angular distributions of ^π-^20Ne elastic scattering are reasonably predicted by the calculations.展开更多
文摘Using core-scattered closed-orbit theory and region-splitting iterative method, we calculated the scaled recurrence spectra of helium atom in parallel electric and magnetic fields. Closed orbits in the corresponding classical system have also been obtained. When we search the closed orbits, in order to remove the Coulomb singularity of the classical Hamiltonian motion equations, we implement the Kustaanheimo-Stiefel transformation, which transforms the system from a three-dimensional to a four-dimensional one. The Fourier transformed spectrum of helium atom has allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The results are compared with those of the hydrogen case, which shows that the core-scattered effects play an important role in the recurrence spectra of the multi-electron Rydberg atom.
文摘Ovarian tumor may occur in women ofany age, but mostly seen in women duringtheir child-bearing period. The disease shouldbe treated mainly by surgical operation,supplemented by radiotherapy and chemo-therapy. However, the above therapies maycause a series of toxic side-effects, such asalopecia, diarrhea, edema, anorexia, nausea,dry mouth, spontaneous perspiration, headache,
文摘During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the field of neutron interferometry and ultra-small angle neutron scattering as well as in the field of radiochemistry, education and training and research in the field of nuclear safeguards and nuclear security. Potential further directions of research are outlined where the Atominstitut of Vienna might concentrate in future.
基金supported by the National Large Facility Project from the National Development and Reform Commissionthe CSNS R&D funds from CAS,Guangdong Province,and Dongguan Citythe National Basic Research Program of China(Grant No.2010CB833102)
文摘The China Spallation Neutron Source(CSNS)is the first accelerator-based multidiscipline user facility to produce pulsed neutrons by tungsten target under collision of a pulsed proton beam with a beam power of 100 kW at a repetition rate of 25 Hz.In this paper,we focus on the physical design of CSNS target station and neutron instruments.Under optimized design,the flat tungsten target and the compact target-moderator-reflector coupling enhance effective cold and thermal neutron output from moderators.Three wing-type moderators supply four different characteristics of neutrons to 19 beamlines primarily for neutron scattering applications.Layout of neutron instruments are conceptually planned for total 20 beamlines,the configuration and specification have been determined for three day-one neutron instruments.All designs are optimized for the Phase I of 100 kW with a upgradable capacity to 500 kW.
基金supported by the Innovation Program of Shanghai Municipal Education Commission(2017–01-07–00-07-E00018)the National Key R&D Program of the MOST of China(2016YFA0300203,2016YFA0300500,2016YFA0301001,and 2018YFE0103200)+6 种基金the National Natural Science Foundation of China(11874119)Shanghai Municipal Science and Technology Major Project(2019SHZDZX04)the Hong Kong Research Grants Council(17303819 and 17306520)supported by the National Natural Science Foundation of China(11875265)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(3He based neutron polarization devices)the Institute of High Energy Physicsthe Chinese Academy of Sciences。
文摘We report thermodynamic and neutron scattering measurements of the triangular-lattice quantum Ising magnet TmMgGaO_(4)in longitudinal magnetic fields.Our experiments reveal a quasi-plateau state induced by quantum fluctuations.This state exhibits an unconventional non-monotonic field and temperature dependence of the magnetic order and excitation gap.In the high field regime where the quantum fluctuations are largely suppressed,we observed a disordered state with coherent magnon-like excitations despite the suppression of the spin excitation intensity.Through detailed semi-classical calculations,we are able to understand these behaviors quantitatively from the subtle competition between quantum fluctuations and frustrated Ising interactions.
基金Supported by National Natural Science Foundation of China under Grant No.11265004
文摘We present an analysis of π-^20Ne elastic scattering at intermediate energy basing on the α＋^16O model of the ^20Ne nucleus and in the framework of Glauber multiple scattering theory. Satisfactory agreement with the general features of the experimental data of pion elastic scattering on the neighboring 4N-type nuclei is obtained without any free parameters. Compared with the experimental angular distributions of pion elastic scattering on ^12 C, ^16O, ^24Mg, and ^28Si nuclei, the diffractive patterns and the positions of the dips and peaks in the angular distributions of ^π-^20Ne elastic scattering are reasonably predicted by the calculations.
