Near-infrared polarimetry of the GG Tauri A binary system

A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.

N-苯基琥珀酰亚胺类的分子和晶体结构及其杀菌活性

业已知晓环酰亚胺类化合物[如N-苯基琥珀酰亚胺(1)、二甲菌核利(2)和乙烯菌核利(3)]对核盘菌和灰葡萄孢具有杀菌活性。为了阐明产生此活性的N-苯基琥珀酰亚胺的结构特征,笔者对化合物(1)中苯环与琥珀酰亚胺基团间的扭转角会否因在苯环中引入取代基而发生变化,若有变化该角与生物活性间又有何种关系进行了研究。