共查询到20条相似文献,搜索用时 0 毫秒
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Considerable progress has been made in the study of proton-emitting nuclei since the first observation of direct proton emission nearly half a century ago. This has led to improvements in our understanding of this rare decay process and provided invaluable nuclear structure data far from the valley of beta stability. This paper reviews the implications of some recent results for exotic iridium, rhenium and tantalum isotopes and considers prospects for future experimental studies of proton-emitting nuclei located at and above the N =82 neutron shell closure. 相似文献
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Quark-hadron duality of three proton spin structure functions g1, g2 and gT are discussed simultaneously. It is found that the onsets of the quark-hadron dualities of g1^p, g2^p and gT^p. are similar and they are expected to be at about Q2~2 GeV2. In addition, our results show that the elastic peak remarkably breaks local quark-hadron duality. 相似文献
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HUANGYu-Hua ZHAOYou-Yuan OU-YANGXiao-Ping LIFu-Ming DINGJian-Dong LIQing-Guo 《中国物理快报》2003,20(6):959-961
A theoretical model was assumed to describe the kinetic processes of light-driven proton pump and motion. The calculation shows that the photovoltage signals are greatly affected by experimental conditions including pulse width of excitation and impedance of measurement system. At the same excitation, only a negative photovoltage signal can be observed with small impedance and both the negative and positive signals can be observed with large impedance. With the same impedance, shorter response time of the pulsed photoelectric signals is responsible for shorter pulsed excitation. All these phenomena are in good agreement with the experimental results. 相似文献
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JETP Letters - We explore possible physical origin of correlation between radio wave and very-high-energy neutrino emission in active galactic nuclei (AGN), suggested by recently reported evidence... 相似文献
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JETP Letters - Effects of parity violation in the interaction of relativistic polarized protons and deuterons are discussed. P-odd asymmetries in the total and elastic scattering cross sections, in... 相似文献
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In the framework of the Glauber model,taking into account the energy loss of the beam proton through the nucleus,we analyse the measured Drell-Yan production cross sections for an 800 GeV proton beam incident on Be,Fe and W nuclear targets,We have found that the nuclear Drell-Yan cross section ration are suppressed due to the energy loss in the initial state.The calculated results of the energy loss are in very good agreement with the Fermilab experiment 866. 相似文献
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Experimental data obtained by the NA35 Collaboration for the difference of the p and \(\bar p\) spectra and the difference of the Λ and \(\bar \Lambda\) spectra (net proton and Λ-hyperon spectra), as well as the inclusive Λ and \(\bar \Lambda\) spectra measured by the NA49, NA57, and STAR Collaborations, are compared with the predictions of the quark-gluon string model. The contribution of string-junction diffusion is calculated, and interaction with nuclear clusters is taken into account along with the corrections for inelastic screening. The level of numerical agreement with experimental data is between 20 and 30%. The predictions for the LHC energy are given. 相似文献
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《Zeitschrift fur Physik C Particles and Fields》1997,75(4):607-618
The electroproduction of ρ mesons with proton diffractive dissociation for Q 2 > 7 GeV2 and the elastic electroproduction of φ mesons for Q 2 > 6 GeV2 are studied in e + p collisions at HERA with the H1 detector, for an integrated luminosity of 2.8 pb-1. The dependence of the cross sections on P t 2 and Q 2 is measured, and the vector meson polarisation obtained. The cross section ratio between proton dissociative and elastic production of ρ mesons is measured and discussed in the framework of the factorisation hypothesis of diffractive vertices. The ratio of the elastic cross section for φ and ρ meson production is investigated as a function of Q 2. 相似文献
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《Magnetic resonance imaging》1996,14(6):691-695
Proton Magnetic Resonance Spectroscopy was carried out at 1.5 T on a patient with histologically proven Pott's spine affecting D11 vertebral body. In addition to the significantly reduced signals from the lipids in the region between 1 and 2 ppm, a prominent resonance at 5.1 ppm is seen. The spectrum is very different from that recorded on the one hand for a normal spine and, on the other, for a tumor arising from the vertebral body of a patient. 相似文献
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GU Bai-Ping REN Zhong-Zhou 《理论物理通讯》2006,46(4):711-716
The elastic scattering of p-^14Be system at Elab = 200 MeV is evaluated within the relativistic impulse approximation. We discuss the effects of the halo neutrons on the three observables of the elastic scattering system, such as differential cross section dσ/ dΩ, analyzing power Ay and spin rotation Q. The results of the three observables of the elastic scattering of p-^14Be system are compared with those of p-^12C and p-^16O systems at the same energy as E1ab = 200 MeV. We have found that in the small angular region the Ay and Q, as well as dσ/dΩ, are quite sensitive to the nucleon density distributions on the surface of the target nucleus and offer some unique behaviors of halo nuclei. 相似文献
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WANG Hong-Min ZHANG Ben-Ai 《理论物理通讯》2005,44(2):326-328
We discuss the consequence of local duality for elastic scattering, and derive a model-independent equation between structure functions at x~1 and elastic electromagnetic form factors. Then the electromagnetic form factors of proton are discussed using the quark-hadro.n duality theory. We also debate the form factor of proton in a bound state.It may be an effective approach to study the form factor of proton in media. 相似文献
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周先荣 《中国物理C(英文版)》2009,33(Z1):82-85
The properties of Be and B isotopes and the corresponding Λ hypernuclei are studied by using a deformed Skyrme Hartree-Fock approach with realistic nucleonic Skyrme forces, pairing correlations, and a microscopically determined lambda-nucleon interaction based on Brueckner-Hartree-Fock calculations of hypernuclear matter. The results suggest that the core nuclei and the corresponding hypernuclei have similar deformations with the same sign. 相似文献
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Microstructure and properties of plastic deformed martensite induced by laser shock processing 总被引:1,自引:0,他引:1
Firstly, 45# steel was quenched by the NEL-2500A rapidly axial flow CO2 laser. The experimental parameters were the laser power of 750 W, the laser beam diameter of 4 mm, the scanning velocity of 7 mm/s. The thickness of coating layer was 0.1 mm and the width was 8 mm. Secondly, the martensite induced by laser quench was shocked by Nd:YAG laser. The parameters of laser shock processing were the wavelength of 1.06 μm, the pulse duration of 23 ns, and the output energy of 16-20 J. The laser was focused on a spot of φ7 mm. K9 optical glass was used as confinement. The sample was coated with black paint 86-1 (the thickness is about 0.025 mm). By testing and analysis of samples which were treated by laser quench and laser quench+shock with transmission electron microscope (TEM), it was discovered that the surface layer of martensite was deformed plastically by laser shock processing. In the secondary hardened zones, there were a lot of slender secondary twin crystal martensites, dislocation tangles, and cel 相似文献
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ZuoWei 《近代物理研究所和兰州重离子加速器实验室年报》2003,(1):6-6
The three-body force effects on the equation of state and its iso-spin dependence of asymmetric nuclear matter and on the proton fraction in neutron star matter have been investigated[1] within Brueckner Hartree-Fock (BHF) approach by using a microscopic three-body force. It is shown that, even in the presence of the three-body force, the empirical parabolic law of the energy per nucleon vs. isospin asymmetry β=(N-Z)/A is fulfilled in the whole asymmetry range 0 ≤β ≤1 and also up to high density. The three-body force provides a strong enhancement of symmetry energy at high density in agreement with relativistic approaches. Thecalculated proton fraction in β stable neutron star matter is given in Fig.l, where the thick solid line is the BHF prediction using AV18 TBF, while the dotted one is the BHF result using AVis. The thin solid line is the prediction of the Dirac-Brueckner approach taken from Ref.[2]. The results extracted according to the phenomenological paramete rizations of the symmetry energy suggested in Ref.[3] are also plotted. It is seen from 相似文献
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Converging spherical and cylindrical elastic–plastic waves in an isotropic work-hardening medium is investigated on the basis of a finite difference method. The small amplitude pressure is applied instantaneously and maintained on the outer surface of a spherical or a cylindrical medium. It is found that for undercritical loading, the induced wave structure is an elastic front followed in turn by an expanding plastic region and an expanding elastic region. For supercritical loading, the elastic front is followed in turn by an expanding plastic region, a narrowing elastic region and an expanding plastic region.After yielding is initiated, the strength of the elastic front is constant and equal to the critical loading pressure. The motion of the continuous elastic–plastic interface is discussed in detail. Spatial distributions of pressure near the axis show the strength of the converging wave is nearly doubled in the reflecting stage. 相似文献