An ab initio calculation of the electric-field gradient(EFG)at the site of a phosphorous impurity substituting an Al atom in α-Al_(3)O_(2) is carried out using the WIEN2k code with the full-potential linearized augme...An ab initio calculation of the electric-field gradient(EFG)at the site of a phosphorous impurity substituting an Al atom in α-Al_(3)O_(2) is carried out using the WIEN2k code with the full-potential linearized augmented plane wave plus local orbital method(LAPW+lo)in the frame of density functional theory.The atomic lattice relaxations caused by the implanted impurities were calculated for two different charged states to well describe the electronic structure of the doped system.The EFG at the site of the phosphorous impurity in the charged supercell calculated with the exchange-correlation potential of the Wu-Cohen generalized gradient approximation(WC-GGA)is 0.573×10^(21) V/m^(2).Then,the nuclear quadrupole moment of the I=3 state in ^(28)P is deduced to be 137 mb from the quadrupole interaction frequency of 190 kHz measured recently by theβ-NQR method.展开更多
The void evolution inα-Al2O3 irradiated by En≥1 MeV neutrons of 3×10^(20)cm^(-2) and post-annealed from 100°C to 1050°C has been studied by a positron annihilation lifetime technique.The void nucleati...The void evolution inα-Al2O3 irradiated by En≥1 MeV neutrons of 3×10^(20)cm^(-2) and post-annealed from 100°C to 1050°C has been studied by a positron annihilation lifetime technique.The void nucleation starts at 500°C.In the annealing temperature region from 550℃ to 750℃,the radius of created voids keeps constant at a value of about 0.29 nm and the number of voids increases with increasing temperature.Afterwards,the radius of voids increases rapidly with the increasing annealing temperature and reaches 1.21nm at 1050℃.展开更多
The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution met...The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution method and calculated by a cranking shell model.A peak structure of the g-factors has been observed for the first time.The measured g-factors confirm the mixed configuration of proton and neutron alignments.展开更多
Great interest has been aroused on deeply-situated Osaka clay since Kobe Earthquake in 1994. In this paper is presented the analysis on the results of a series of lab tests on Osaka clay situated from 100 m to 1500 m ...Great interest has been aroused on deeply-situated Osaka clay since Kobe Earthquake in 1994. In this paper is presented the analysis on the results of a series of lab tests on Osaka clay situated from 100 m to 1500 m under the ground. The wave velocity method, bender element method, LDT and the formula derived by the authors are used, focus is put on the pre-failure mechanical behavior of the clay. The analysis shows that, (i) pore-pressure coefficient B is less than 1.0, (ii) the relationship between shear modulus and Poisson's ratio is not in agreement with that reported before, (iii) the modulus measured with LDT is still less than that measured with bender element method, and (iv) there are two threshold strains, within which the clay can be considered as elastic, and both of them are larger than that reported before.展开更多
Reaction and interaction cross sections of 17C on a carbon target have been re-analyzed using the modified Glauber model. The analysis with a deformed Woods-Saxon density/potential suggests a big deformation structure...Reaction and interaction cross sections of 17C on a carbon target have been re-analyzed using the modified Glauber model. The analysis with a deformed Woods-Saxon density/potential suggests a big deformation structure for 17C. The existence of a tail in the density distribution supports the possibility of it being a one-neutron halo structure. Under a deformed core plus a single-particle assumption, analysis shows a dominant d-wave of the valence neutron in 17C.展开更多
We study the reaction cross sections （σR） and root-mean-square （RMS） radii of ^8Li and ^8B, the halo-like nuclei, with stable target ^12C, ^27Al and ^9Be within the standard optical-limit Glauber model, using den...We study the reaction cross sections （σR） and root-mean-square （RMS） radii of ^8Li and ^8B, the halo-like nuclei, with stable target ^12C, ^27Al and ^9Be within the standard optical-limit Glauber model, using densities obtained from relativistic mean-field （RMF） formalisms and other types of distributions. It is found that the experimental σR can be reproduced well at high energy. The RMS radius and Ar extracted by RMF- theory and harmonic oscillator distribution are compared. larger than those of SLi. In addition, we analyze in detail the We find that the RMS radius and Ar of SB are relationship between σR and density distribution.展开更多
Direct radiative capture processes are well described by a spherical potential model. Since most nuclei are not spherical, and in order for the model to explain direct radiative captures more accurately, the effect of...Direct radiative capture processes are well described by a spherical potential model. Since most nuclei are not spherical, and in order for the model to explain direct radiative captures more accurately, the effect of nuclear deformation has been analyzed with q-deformed Woods-Saxon potential in this work. The results imply that nuclear deformation largely affects the direct radiative capture, and it should be taken into account when discussing direct capture reactions.展开更多
基金Supported by National Natural Science Foundation of China under Grant Nos 10975189 and 91126002.
文摘An ab initio calculation of the electric-field gradient(EFG)at the site of a phosphorous impurity substituting an Al atom in α-Al_(3)O_(2) is carried out using the WIEN2k code with the full-potential linearized augmented plane wave plus local orbital method(LAPW+lo)in the frame of density functional theory.The atomic lattice relaxations caused by the implanted impurities were calculated for two different charged states to well describe the electronic structure of the doped system.The EFG at the site of the phosphorous impurity in the charged supercell calculated with the exchange-correlation potential of the Wu-Cohen generalized gradient approximation(WC-GGA)is 0.573×10^(21) V/m^(2).Then,the nuclear quadrupole moment of the I=3 state in ^(28)P is deduced to be 137 mb from the quadrupole interaction frequency of 190 kHz measured recently by theβ-NQR method.
基金Supported in par t by the National Natural Science Foundation of China under Grant No.19835050the Nuclear Indus try Science Foundation of China under Grant No.H7196BO116the Contract of 97J11.2.8HZ010.
文摘The void evolution inα-Al2O3 irradiated by En≥1 MeV neutrons of 3×10^(20)cm^(-2) and post-annealed from 100°C to 1050°C has been studied by a positron annihilation lifetime technique.The void nucleation starts at 500°C.In the annealing temperature region from 550℃ to 750℃,the radius of created voids keeps constant at a value of about 0.29 nm and the number of voids increases with increasing temperature.Afterwards,the radius of voids increases rapidly with the increasing annealing temperature and reaches 1.21nm at 1050℃.
基金Supported by the National Natural Science Foundation of China under Grant No.19775070.
文摘The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution method and calculated by a cranking shell model.A peak structure of the g-factors has been observed for the first time.The measured g-factors confirm the mixed configuration of proton and neutron alignments.
文摘Great interest has been aroused on deeply-situated Osaka clay since Kobe Earthquake in 1994. In this paper is presented the analysis on the results of a series of lab tests on Osaka clay situated from 100 m to 1500 m under the ground. The wave velocity method, bender element method, LDT and the formula derived by the authors are used, focus is put on the pre-failure mechanical behavior of the clay. The analysis shows that, (i) pore-pressure coefficient B is less than 1.0, (ii) the relationship between shear modulus and Poisson's ratio is not in agreement with that reported before, (iii) the modulus measured with LDT is still less than that measured with bender element method, and (iv) there are two threshold strains, within which the clay can be considered as elastic, and both of them are larger than that reported before.
基金Supported by Anhui University of Science and Technology(11130)
文摘Reaction and interaction cross sections of 17C on a carbon target have been re-analyzed using the modified Glauber model. The analysis with a deformed Woods-Saxon density/potential suggests a big deformation structure for 17C. The existence of a tail in the density distribution supports the possibility of it being a one-neutron halo structure. Under a deformed core plus a single-particle assumption, analysis shows a dominant d-wave of the valence neutron in 17C.
基金Supported by One Hundred Person Project of Chinese Academy of Sciences (26010701)Knowledge Innovation Project of Chinese Academy of Sciences (KJCX2-SW-N13,KJCX3-SYW-N2)National Natural Science Foundation of China (10675156)
文摘We study the reaction cross sections （σR） and root-mean-square （RMS） radii of ^8Li and ^8B, the halo-like nuclei, with stable target ^12C, ^27Al and ^9Be within the standard optical-limit Glauber model, using densities obtained from relativistic mean-field （RMF） formalisms and other types of distributions. It is found that the experimental σR can be reproduced well at high energy. The RMS radius and Ar extracted by RMF- theory and harmonic oscillator distribution are compared. larger than those of SLi. In addition, we analyze in detail the We find that the RMS radius and Ar of SB are relationship between σR and density distribution.
基金the financial support provided by Anhui University of Science and Technology(11130,QN201315)
文摘Direct radiative capture processes are well described by a spherical potential model. Since most nuclei are not spherical, and in order for the model to explain direct radiative captures more accurately, the effect of nuclear deformation has been analyzed with q-deformed Woods-Saxon potential in this work. The results imply that nuclear deformation largely affects the direct radiative capture, and it should be taken into account when discussing direct capture reactions.
