[[alternative]]Interferometer study of CO & CS in comet Hale-Bopp (C/1995 O1)

[[abstract]]摘要 我們使用BIMA (Berkeley-Illinois-Maryland Association) 毫米波干涉儀陣列觀測海爾-包普彗星。研究結果顯示CO和CS氣體分子之分布呈現的刺狀結構，其成因可能來自於彗核之氣體或塵埃噴流；交叉相關所得之CO及CS光譜呈現不對稱形狀，藍移端譜線顯著增強，應是彗核面對太陽方向之氣體產生率較高之故。比較Haser模式與觀測結果，驗證了理論預測的CO尺度長度，並且證實CO氣體分子主要是自彗核直接昇華而來，但是仍有少部分CO分子是來自彗髮中的冰塵顆粒。直接來自彗核的CO分子豐度，可反映出太陽系形成初始之含量。經觀測得到CO分子的柱密度為2.31 × 10^16 cm^-2，CS分子為2.32 ×10^14 cm^-2。使用Haser模式求得CO的氣體產生率為1.49 ×10^30 s^-1，CS的產生率約為1.91 ×10^28 s^-1。比較海爾-包普彗星、其他彗星的CO/H2O豐度比，發現長週期彗星和哈雷家族彗星CO/H2O豐度比顯著的較木星家族彗星的值來的多；海爾-包普彗星CO/H2O豐度比與恆星形成區中星際冰塵顆粒的豐度值相當，卻顯著的比巨大分子雲中熱分子雲核氣相分子少，顯示海爾-包普彗星極可能是在含有大量星際冰粒和塵埃的太陽星雲塌陷過程中形成，而不是來自星際雲氣的凝結。

Investigation of the Rheological Properties and Chemical Structure of Asphalt under Multiple Aging Conditions of Heat, UV and Aqueous Solution

During the service period, asphalt materials are affected by various natural factors, including heat, ultraviolet light, oxygen and moisture, etc., resulting in the reduction of pavement performance, the increase of pavement distress and shortening of service life. This study aims to investigate the aging performance of asphalt under multiple aging conditions of heat, UV and aqueous solution. Thermal-oxygen aging, UV aging and hydrostatic erosion tests were carried out sequentially on asphalt. The rheological properties, chemical structure and element composition of asphalt were characterized before and after aging, and the effect mechanism of multiple conditions was discussed. The results show that the multiple conditions of heat and UV can increase the rutting resistance and weaken the cracking resistance of asphalt. However, the effect degree of UV decreases gradually with the deepening of aging degree. Additionally, the effect of water on the physicochemical properties is less than that of UV; however, water can increase the sensitivity of physicochemical properties to UV. In summary, this study explored the short-term cycling effect of heat, light and water on asphalt and provided an idea for simulation test of asphalt under multiple aging condition.Materials and Environmen