ELECTRON DIFFRACTION PATTERNS OF GD-FE THIN FILMS DEPOSITED AT LOW TEMPERATURE

In a wide range of composition Gd-Fe thin films become amorphous. The diffraction patterns of diffuse halo rings are distinguished into three types. The type 1 with a single strong halo appears in the 30-60 percent iron films of any thickness. The type 2 with two strong halos of nearly the same intensity and the type 3 with two halos of different intensities appears in the 60-90 percent iron films thicker and thinner than about 100 A, respectively. Within one type of pattern the peak position of halos shifts with the variation of composition and thickness of the film. The type 2 pattern can be well correlated to the diffraction pattern of the intermetallic compound Fe_3Gd with a rhombohedral structure. The other patterns are difficult to relate with a special type of crystalline phase

Estrogenic regulation of social behavior and sexually dimorphic brain formation

It has long been known that the estrogen, 17β-estradiol (17β-E), plays a central role for female reproductive physiology and behavior. Numerous studies have established the neurochemical and molecular basis of estrogenic induction of female sexual behavior, i.e., lordosis, in animal models. In addition, 17β-E also regulates male-type sexual and aggressive behavior. In males, testosterone secreted from the testes is irreversibly aromatized to 17β-E in the brain. We discuss the contribution of two nuclear receptor isoforms, estrogen receptor (ER)α and ERβ to the estrogenic regulation of sexually dimorphic brain formation and sex-typical expression of these social behaviors. Furthermore, 17β-E is a key player for social behaviors such as social investigation, preference, recognition and memory as well as anxiety-related behaviors in social contexts. Recent studies also demonstrated that not only nuclear receptor-mediated genomic signaling but also membrane receptor-mediated non-genomic actions of 17β-E may underlie the regulation of these behaviors. Finally, we will discuss how rapidly developing research tools and ideas allow us to investigate estrogenic action by emphasizing behavioral neural networks

強磁性薄膜の磁化リップル起原に関する電子顕微鏡的研究

京都大学0048新制・論文博士理学博士論理博第248号新制||理||98(附属図書館)2282(主査)教授 高木 秀夫, 教授 可知 祐次, 教授 水渡 英二, 教授 高田 利夫学位規則第5条第2項該当Kyoto UniversityDA

MAGNETIC ANISOTROPY DISTRIBUTED NEAR THE SURFACE OF AMORPHOUS RIBBONS

Magnetic anisotropy in an amorphous ribbon of Fe_Ni_P_B_6, Allied Chemical Metglas 2826, has been studied. Magnetic domain structures and the in-plane anisotropy were measured as a function of the depth from the ribbon surface by a powder technique, transmission electron microscopy and a torque method. The data have an obvious connection with the surface topography of the ribbon that is introduced in the melt and quench process. Groups of fine domains, which originate from the perpendicular anisotropy, cover a large part of the as-quenched surface. They diminish rapidly with depth. In accordance with the disappearance of fine domains the in-plane anisotropy also decreases. It shows a maximum, an order of 10^5 erg/cc, at the surface and decreases one or two orders smaller at the center of the ribbon. These results suggest an inhomogeneous distribution of internal stress that is introduced at the quenching process