Isoscalar monopole excitations in 16^{16}O: α\alpha-cluster states at low energy and mean-field-type states at higher energy

Isoscalar monopole strength function in $^{16}$O up to $E_{x}\simeq40$ MeV is discussed. We found that the fine structures at the low energy region up to $E_{x} \simeq 16$ MeV in the experimental monopole strength function obtained by the $^{16}$O$(\alpha,\alpha^{\prime})$ reaction can be rather satisfactorily reproduced within the framework of the $4\alpha$ cluster model, while the gross three bump structures observed at the higher energy region ($16 \lesssim E_{x} \lesssim 40$ MeV) look likely to be approximately reconciled by the mean-field calculations such as RPA and QRPA. In this paper, it is emphasized that two different types of monopole excitations exist in $^{16}$O; one is the monopole excitation to cluster states which is dominant in the lower energy part ($E_{x} \lesssim 16$ MeV), and the other is the monopole excitation of the mean-field type such as one-particle one-hole ($1p1h$) which {is attributed} mainly to the higher energy part ($16 \lesssim E_{x} \lesssim 40$ MeV). It is found that this character of the monopole excitations originates from the fact that the ground state of $^{16}$O with the dominant doubly closed shell structure has a duality of the mean-field-type {as well as} $\alpha$-clustering {character}. This dual nature of the ground state seems to be a common feature in light nuclei.Comment: 35 pages, 5 figure

A topology optimization method based on the level set method incorporating a fictitious interface energy

This paper proposes a new topology optimization method, which can adjust the geometrical complexity of optimal configurations, using the level set method and incorporating a fictitious interface energy derived from the phase field method. First, a topology optimization problem is formulated based on the level set method, and the method of regularizing the optimization problem by introducing fictitious interface energy is explained. Next, the reaction–diffusion equation that updates the level set function is derived and an optimization algorithm is then constructed, which uses the finite element method to solve the equilibrium equations and the reaction–diffusion equation when updating the level set function. Finally, several optimum design examples are shown to confirm the validity and utility of the proposed topology optimization method

Investigation of 9{}^9Be from nonlocalized clustering concept

The nonlocalized aspect of clustering, which is a new concept for self-conjugate nuclei, is extended for the investigation of the N{\not=}Z nucleus ${}^9$Be. A modified version of the THSR (Tohsaki-Horiuchi-Schuck-R\"opke) wave function is introduced based on the container picture. It is found that the constructed negative-parity THSR wave function is very suitable for describing the cluster states of ${}^9$Be. Namely the nonlocalized clustering is shown to prevail in ${}^9$Be. The calculated binding energy and radius of ${}^9$Be are consistent with calculations in other models and with experimental values. The squared overlaps between the THSR wave function and the Brink+GCM wave function for the $3/2^-$ rotational band of ${}^9$Be are found to be near 96%. Furthermore, by showing the density distribution of the ground state of ${}^9$Be, the {\pi}-orbit structure is naturally reproduced by using this THSR wave function.Comment: 20 pages, 5 figure

Alpha-Particle Clustering in Nuclei and Four-Alpha-Particle Condensation in 16O

Low density states near the 3 and 4 breakup threshold in 12C and 16O, respectively, are discussed in terms of the -particle condensation. Calculations are performed in OCM(Orthogonality Condition Model) and THSR (Tohsaki- Horiuchi-Schuck-Röpke) approaches. The 0+2 state in 12C and the 0+6 state in 16O are shown to have dilute density structures and give strong enhancement of the occupation of the S-state c.o.m. orbital of the -particles. The 0+6 state in 16O has a large component of +12C(0+2 ) configuration, which is another reliable evidence of the state to be of 4 condensate nature. The possibility of the existence of -particle condensed states in heavier n nuclei is also discussed

SCF[FBXO2]ユビキチンリガーゼ複合体は細菌の表層糖鎖を認識することでゼノファジーを誘導する

京都大学新制・課程博士博士(医学)甲第23605号医博第4792号京都大学大学院医学研究科医学専攻(主査)教授 長尾 美紀, 教授 竹内 理, 教授 秋山 芳展学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

Press-variants in John Marston’s Antonio Plays (1602)

Article人文科学論集 21: 43-46 (1987)departmental bulletin pape