Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The （R）-and （S）-2-n-butylbutanedioic ac...Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The （R）-and （S）-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with（S）-（ - ） or（R）-（ ＋ ）-α- methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with（R）-（ ＋ ）-α-methylbenzylamine and（S）- phenylalanine methyl ester.展开更多
The properties of the ground and excited-state（γ-and β-bands） of ^168-178 Hf nuclei have been studied.The ratio r（I ＋2/I） and Eγ（I→I-2）/I have been calculated as a function of the spin（I） to determine the...The properties of the ground and excited-state（γ-and β-bands） of ^168-178 Hf nuclei have been studied.The ratio r（I ＋2/I） and Eγ（I→I-2）/I have been calculated as a function of the spin（I） to determine the groundstate evolution. The results indicate that these isotopes have a rotational property SU（3）. The energy levels for the ground-state, γ-and β-bands of ^168-178 Hf have been calculated using the Interacting Boson Model and Semi Empirical Formula（SEF）. The parameters of the best fit to the measured data are determined. The behavior of energy and B（E2） ratios in the ground state band are examined.展开更多
The nuclear structure of the actinide even-even thorium isotopes from A=230-234 have been investigated within the framework of the Interacting Boson Model（IBM-1）. Predictions are given for the excited state energies...The nuclear structure of the actinide even-even thorium isotopes from A=230-234 have been investigated within the framework of the Interacting Boson Model（IBM-1）. Predictions are given for the excited state energies for the ground state, β and γ-bands, the transition probabilities between these states, the rotational moment of inertia, and the energy staggering in the γ-band energies. The results of these calculations are compared with the experimental data on these isotopes.展开更多
The Generalized Collective Model (GCM) is applied to the even even neutron rich 104,106,108 Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy ...The Generalized Collective Model (GCM) is applied to the even even neutron rich 104,106,108 Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy Surfaces (PES) for the 104,106,108 Mo isotopes are calculated. The PES of all these isotopes show a prolate minimum which becomes more pronounced in 106 Mo. The results are in agreement with the recent experimental report but are different from the viewpoint of the triaxial rotors, or γ soft deformation. Through a systematic study of PES, it is suggested that the even even neutron rich 104,106,108 Mo isotopes have prolate deformation.展开更多
基金Supported by the National Basic Research Priority Program(No. 2003CCA027).
文摘Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The （R）-and （S）-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with（S）-（ - ） or（R）-（ ＋ ）-α- methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with（R）-（ ＋ ）-α-methylbenzylamine and（S）- phenylalanine methyl ester.
基金the University of Mosul,College of Education for Pure Science,Department of PhysicsUniversity of Kerbala,College of Science,Department of Physics for supporting this work
文摘The properties of the ground and excited-state（γ-and β-bands） of ^168-178 Hf nuclei have been studied.The ratio r（I ＋2/I） and Eγ（I→I-2）/I have been calculated as a function of the spin（I） to determine the groundstate evolution. The results indicate that these isotopes have a rotational property SU（3）. The energy levels for the ground-state, γ-and β-bands of ^168-178 Hf have been calculated using the Interacting Boson Model and Semi Empirical Formula（SEF）. The parameters of the best fit to the measured data are determined. The behavior of energy and B（E2） ratios in the ground state band are examined.
基金the invaluable support of the College of Science at the University of Kerbala is warmly acknowledged
文摘The nuclear structure of the actinide even-even thorium isotopes from A=230-234 have been investigated within the framework of the Interacting Boson Model（IBM-1）. Predictions are given for the excited state energies for the ground state, β and γ-bands, the transition probabilities between these states, the rotational moment of inertia, and the energy staggering in the γ-band energies. The results of these calculations are compared with the experimental data on these isotopes.
文摘The Generalized Collective Model (GCM) is applied to the even even neutron rich 104,106,108 Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy Surfaces (PES) for the 104,106,108 Mo isotopes are calculated. The PES of all these isotopes show a prolate minimum which becomes more pronounced in 106 Mo. The results are in agreement with the recent experimental report but are different from the viewpoint of the triaxial rotors, or γ soft deformation. Through a systematic study of PES, it is suggested that the even even neutron rich 104,106,108 Mo isotopes have prolate deformation.
