Wong, Ka Wing = 含有暗物質核心的白矮星的物理性質 / 黃家榮. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 81-86). / Abstracts in English and Chinese. / Wong, Ka Wing = Han you an wu zhi he xin de bai ai xing de wu li xing zhi / Huang Jiarong. / Abstract --- p.ii / Acknowledgement --- p.iv / List of Abbreviations --- p.v / List of Figures --- p.vi / Table of Contents --- p.xi / Chapter 0 --- Introduction --- p.1 / Chapter 1 --- White Dwarfs --- p.5 / Chapter 1.1 --- Introduction --- p.5 / Chapter 1.2 --- Observation --- p.6 / Chapter 1.3 --- Mass-Radius Relationship & Mass Limit --- p.9 / Chapter 1.4 --- Type Ia Supernovae --- p.14 / Chapter 2 --- Dark Matter --- p.16 / Chapter 2.1 --- Introduction --- p.16 / Chapter 2.2 --- Observational Evidences --- p.17 / Chapter 2.3 --- Dark Matter Candidates and their Categorization --- p.21 / Chapter 3 --- Moon-sized White Dwarf with a Dark Matter Core --- p.26 / Chapter 3.1 --- Introduction --- p.26 / Chapter 3.2 --- Model --- p.29 / Chapter 3.3 --- Results --- p.32 / Chapter 3.3.1 --- Typical Density Profile --- p.32 / Chapter 3.3.2 --- M-R Curves --- p.33 / Chapter 3.3.3 --- Scaling in n --- p.35 / Chapter 3.3.4 --- BPS Equation of State --- p.40 / Chapter 3.4 --- Discussion --- p.41 / Chapter 4 --- Newtonian Hydrodynamic Simulation of a Spherically Symmetric Star --- p.44 / Chapter 4.1 --- Introduction --- p.44 / Chapter 4.2 --- WENO Scheme --- p.46 / Chapter 4.3 --- Runge-Kutta Time Discretization --- p.48 / Chapter 4.4 --- Fluid Dynamics without Gravity in One Dimension --- p.49 / Chapter 4.4.1 --- Riemann Problem Tests --- p.50 / Chapter 4.5 --- Spherically Symmetric Fluid Dynamics without Gravity --- p.54 / Chapter 4.5.1 --- Diffusion Problem --- p.55 / Chapter 4.6 --- Spherically Symmetric Star --- p.57 / Chapter 4.6.1 --- Radial Oscillation of a White Dwarf --- p.58 / Chapter 4.6.2 --- Radial Oscillation of a White Dwarf with a Point-Sized Dark Matter Core --- p.64 / Chapter 4.7 --- Discussion --- p.68 / Chapter 5 --- Newtonian Hydrodynamic Simulation of a Spherically Symmetric Two-Fluid Star --- p.69 / Chapter 5.1 --- Introduction --- p.69 / Chapter 5.2 --- Spherically Symmetric Two-Fluid Stars --- p.70 / Chapter 5.2.1 --- A White Dwarf with a Dark Matter Core --- p.71 / Chapter 5.3 --- Discussion --- p.77 / Chapter 6 --- Summary --- p.79 / Bibliography --- p.81

The viscin coating of seeds from Arceuthobium tsugense was analyzed histochemically. The results indicated that the viscin is composed of two components. The first is a muculagenous pectic compound which surrounds the entire seed and accounts for a number of observed phenomenon such as stickiness, water holding capacity and the ability to undergo repeated drying and rehydration. The second component is made up of a large number of cellulose strands which are attached to the endocarp and run throughout the pectic coating. Scanning electron micrographs show that they are thought to be important in maintaining the integrity of the pectic coating. The significance of these findings is discussed with respect to establishment of the parasite.

Thesis (Ph. D.)--Texas Christian University, 2007. / Title from dissertation title page (viewed Dec. 10, 2007). Includes abstract. Includes bibliographical references.

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We present updated observations of a pilot survey of 14 pulsating DA white dwarfs, monitored for evidence of center-of-mass motion caused by a planetary companion. We have nearly doubled the number of periodicites for which we can produce O-C diagrams that document pulse arrival times from our stars, and have implemented a method to minimize the apertures we use in our reductions in order to reduce sky noise. In addition to a previously published candidate, GD66, we have identi fed at least four more systems worthy of rigorous observational follow-up. We have also implemented a method, a generalized Lomb-Scargle periodogram, that takes into account weighted points in order to characterize any periodic behavior present in our O-C diagrams. For at least one DAV within this same sample, we have found strong observational evidence for an evolutionary time scale (via the rate of period change) that is inconsistent with cooling alone. In that star, WD0111+0018, we report for the first time measurement of the rate of period change of nonlinear combination frequencies in a pulsating white dwarf. We speculate that this may be caused by a changing rotation rate that aff ects only modes with m not equal to 0. / text

In this thesis I present our recent work on gamma-ray searches for dark matter with the Fermi Large Area Telescope (Fermi-LAT). We have targeted dwarf spheroidal galaxies since they are very dark matter dominated systems, and we have developed a novel joint likelihood method to combine the observations of a set of targets. In the first iteration of the joint likelihood analysis, 10 dwarf spheroidal galaxies are targeted and 2 years of Fermi-LAT data is analyzed. The resulting upper limits on the dark matter annihilation cross-section range from about 10−26 cm3 s−1 for dark matter masses of 5 GeV to about 5 × 10−23 cm3 s−1 for dark matter masses of 1 TeV, depending on the annihilation channel. For the first time, dark matter models with a cross section above the canonical thermal relic cross section (∼ 3 × 10−26 cm3 s−1) are strongly disfavored by a gamma-ray experiment. In the second iteration we include 15 dwarf spheroidal galaxies in the combined analysis, employ 4 years of data and an improved calculation of the dark matter density. The obtained upper limits range from about 10−26 cm3 s−1 for dark matter masses of 2 GeV to about 10−21 cm3 s−1 for dark matter masses of 10 TeV, depending on the annihilation channel. I briefly describe some of the evidence for dark matter, the Fermi-LAT instrument and public data releases, dwarf spheroidal galaxies, likelihood analysis, and results from analyses of Fermi-LAT data. I also document some of the tests made to verify the method and to compare different analysis setups.

Phodopus campbelli is a naturally biparental dwarf hamster with males so paternal they will act as midwives during the birth of their litter. The hormonal regulation of parental behaviour has been well established in many species. However, to date, no causal mechanism for the extensive paternal behaviour displayed by male P. campbelli has been discovered. Recently, activity at the progesterone receptor has been shown to inhibit infant-directed behaviour in male mice. Therefore, the first study in this thesis was carried out to determine if antagonism of the progesterone receptor (PR) would enhance infant-directed care behaviour in naïve P. campbelli males. Despite detectable serum progesterone concentration in males, PR antagonism did not alter progesterone concentration, nor did it alter infant-directed behaviour in males with antagonized PR in adulthood. A slight increase in the latency to retrieve a pup seen in males with antagonized PR during adolescence suggests that there may be a developmental effect of PR activity on infant-directed behaviour in adulthood. Neonatal male rats express high levels of PR in brain regions important for parental behaviour. Since hormones can act very early in life to organize adult behaviour, the second study was carried out to determine if progesterone acting much earlier than adolescence is important in the regulation of paternal behaviour in P. campbelli adulthood. Males were treated daily for the first week of life with transdermal progesterone, which increased neonatal serum progesterone concentration fivefold. Despite the significant increase in progesterone (and therefore presumably activity at the PR), male behaviour in three different stages of adulthood (sexually naïve, during the birth of the male’s first litter, and in new fatherhood) towards pups was not altered. Measures of paternal contribution such as pup weight throughout the lactational period were altered by progesterone treatment during the neonatal period, but litter quality was ultimately high in both groups. Therefore, activity at the PR in adulthood, puberty, or during the neonatal period does not inhibit paternal behaviour in the naturally biparental hamster, P. campbelli. Thus, progesterone and its receptor do not organizationally or activationally regulate paternal behaviour in P. campbelli. / Thesis (Master, Biology) -- Queen's University, 2009-09-04 13:23:18.733

IP Peg is a member of a family of star systems known as cataclysmic variable stars, CVs. CVs are star systems in which a red dwarf star orbits a white dwarf and mass transfer is taking place from the red dwarf to the white dwarf. The mass ratio of the two component stars has been found the most difficult parameter to determine. Tools used in the analysis of mass-ratio included the differential photometric light curve of IP Peg, Doppler tomograms, and spectral data covering the HP emission-line. The mass ratio was found to lie in the range, q = 0.44 ± 0.14. The inclination lies in the range i = 81.5° ± 8.5°. Finally, the accretion disk radius was 0.342 times the distance between the stars. The analysis of the parameters of eclipsing CV systems like IP Peg provides a rare opportunity that helps in the understanding of other CV systems. / Department of Physics and Astronomy

主催：JST/CREST，Vrije University, ALTERRA, IBPC