生分解性ポリエステルの環境分解性と材料寿命制御

学位記番号：理工博甲19

Why do we need ‘myth-busting’ in the study of Sino–African relations?

The literature on Sino–African relations has debated whether or not China's growing presence is a threat to Western or African interests, and has come to the conclusion that China's behavior is not uniquely immoral. Many countries, including Western liberal democracies, similarly give aid to local autocrats to secure natural resources. Why, then, has so much effort been made to come to this perhaps unsurprising conclusion? We argue that the literature on Chinese foreign policy remains heavily influenced by Western states' policy interests, resulting in an impoverished debate that is primarily concerned with the idea of a China threat. In order to recover the diversity in our research on Chinese foreign policy, we argue for the need to go beyond the confines of Western strategic interests

Total reaction cross section on a deuteron target and the eclipse effect of the constituent neutron and proton

Background: Eclipse effect of the neutron and proton in a deuteron target is essential to correctly describe high-energy deuteron scattering. The nucleus-deuteron scattering needs information not only on the nucleus-proton but also the nucleus-neutron interaction, for which no direct measurement of the nucleus-neutron cross sections is available for unstable nuclei. Purpose: We systematically evaluated the total reaction cross sections by a deuteron target to explore the feasibility of extracting the nucleus-neutron interaction from measurable cross sections. Methods: High-energy nucleus-deuteron collision is described by the Glauber model, in which the proton and neutron configuration of the deuteron is explicitly taken into account. Results: Our calculation reproduces available experimental total reaction cross section data on the nucleus-deuteron scattering. The possibility of extracting the nucleus-neutron total reaction cross section from nucleus-deuteron and nucleus-proton total reaction cross sections is explored. The total reaction cross sections of a nucleus by proton, neutron, and deuteron targets can be expressed, to good accuracy, in terms of the nuclear matter radius and neutron skin thickness. Incident-energy dependence of the total reaction cross sections is examined. Conclusions: The total reaction cross section on a deuteron target includes information on both the nucleus-neutron and nucleus-proton profile functions. Measuring the cross sections by deuteron and proton targets is a promising tool to extract the nuclear size properties.Comment: 9 pages, 5 figures, to appear in Phys. Rev.