Thesis (M.A.)--Zheng zhi zuo zhan xue xiao. / Bibliography: p. 143-148.

Thesis (doctoral)--Georg-August-Universität zu Göttingen, 1983. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 238-242).

Thesis (M.A.)--Zhongguo wen hua xue yuan san min zhu yi yan jiu suo. / Bibliography: p.99-107.

Undergraduate honors paper--Mount Holyoke College, 2007. Dept. of Astronomy. / Includes bibliographical references (leaves i-vi).

The study of the ionosphere over the sunrise period is necessary for an understanding of the vtiriations in layer structure with time and has been a topic of research of many workers. On the whole these investigations have been restricted to a study of critical frequency variations with relatively short intervals of a few minutes between successive records, of N-h curves deduced from ionograms with long intervals (15 minutes or so) between successive N-h curves or of continuously monitored single frequency reflections. Not one of the three techniques is entirely satisfactory for a detailed study of ionospheric behaviour over sunrise. The first two do not give a sufficiently clear indication of what happens in the initial stages of layer development, while from the third incomplete data is obtained as to what is happening at a specific electron-density level. For this reason a preliminary investigation of the ionosphere over sunrise was made at Rhodes University during August, 1959. The records were obtained at four-and-a-half minute intervals and scaled by the method of KELSO (1952 ). "Many of t he results were inconclusive but it appeared that records would have to be taken at approximately one minute intervals and reduced to N-h curves by a scaling technique which made full allowance for low-level ionization if useful results were to be obtained. An attempt has been made in this thesis to investigate the behaviour of the ionosphere over sunrise more fully than can be done by the three techniques referred to. A number of observed phenomena are also examined. Part I deals with the theoretical background to ionosphere physics in general and describes the equipment, equipment modifications and experimental procedure. Part II presents the results obtained. The records for a largescale travelling disturbance are analysed. Various observed phenomena are described and discussed. A simple method of obtaining production rates from experimental data is described. The implications of the observed variations of production rates with height and time are discussed. Suggestions for further research and improvement of the methods used arc made in Charter 9.

The thesis presents a comparison of data obtained from the solar radio spectrograph RT5 in Ondřejov and data from the space probe SDO. In the theoretical part of the thesis the solar corona and the current state of knowledge are briefly described. The practical part is devoted to the processing of obtained data using developed programs. From all of structures found in the spectrograms, zebra structures have been selected for more detailed study.

Recent observations have shown that coronal shocks driven by coronal mass ejections can develop and accelerate particles within several solar radii in large solar energetic particle (SEP) events. Motivated by this, we present an SEP acceleration study that including the process in which a fast shock propagates through a streamer-like magnetic field with both closed and open field lines in the low corona region. The acceleration of protons is modeled by numerically solving the Parker transport equation with spatial diffusion both along and across the magnetic field. We show that particles can be sufficiently accelerated to up to several hundred MeV within 2-3 solar radii. When the shock propagates through a streamer-like magnetic field, particles are more efficiently accelerated compared to the case with a simple radial magnetic field, mainly due to perpendicular shock geometry and the natural trapping effect of closed magnetic fields. Our results suggest that the coronal magnetic field configuration is an important factor for producing large SEP events. We further show that the coronal magnetic field configuration strongly influences the distribution of energetic particles, leading to different locations of source regions along the shock front where most high-energy particles are concentrated. This work may have strong implications for SEP observations. The upcoming Parker Solar Probe will provide in situ observations for the distribution of energetic particles in the coronal shock region, and test the results of the study.

No description available.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22254号 / 理博第4568号 / 新制||理||1656(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 一本 潔, 准教授 浅井 歩, 教授 柴田 一成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

The experiences of the Apollo lunar landings revealed the danger lunar dust can pose to surrounding hardware, outposts, and orbiting spacecraft. Future lunar missions such as the Artemis program will require more information about the trajectories of ejecta blown by landers to protect orbiting spacecraft such as the Lunar Gateway. In this paper, we simulate lunar lander ejecta trajectories using the Mercury N-body integrator. We placed cones of test particles on the Moon at the North Pole, South Pole, and Equator with various ejection speeds and angles. The results show that particles ejected at speeds near the Moon's escape velocity can take from several days to weeks to re-impact the lunar surface. The time particles spend in the vicinity of the Moon varies mostly by location. Particles stay aloft after 30 days at launch speeds as low as 2.142 km/s when launched from the Equator. Number density maps and flux density maps of the particle trajectories reveal that particles launched from the South Pole are likely to impact the Lunar Gateway at its orbit near periselene at ejection speeds as low as 2.142 km/s. Particles launched from the Equator also reach the altitude of the Gateway orbit. Particles ejected from the North Pole can impact the Gateway along its orbit at ejections speeds somewhere between 2.3324 and 2.3562 km/s.