【作者】 史旺林；

【导师】 刘振兴；

【作者基本信息】 中国科学院研究生院（空间科学与应用研究中心） ， 空间物理学， 2005， 博士

【摘要】 本文利用cluster卫星数据对磁层顶边界层的小尺度结构作了分析研究,并对一个可能的宇宙线源模型做了初步的研究。 陈涛等的数值模拟研究表明,当边界层受到不均匀横向剪切流冲击时,被冲击的同向磁场区磁力线逐渐弯曲,在弯曲的反磁场区,出现磁岛,然后再电流片区发生磁场重联,且逐渐形成准稳态的“反K型”的重联结构,在法向上,磁场出现多极性。 磁层顶边界层可以看作是受到非均匀太阳风动压冲击的边界层。因此,在磁层顶的局域法向上的速度沿着切线方向存在剪切,并且磁场出现多极结构。我们利用Cluster卫星穿越磁层顶时FGM探测到的磁场数据,利用磁场的最小变量分析方法,计算了在2001年2月20日的一次穿越中磁层顶的法向矢量,并发现在法向上,磁场的确表现出了多极结构,再利用CIS仪器探测到的太阳风速度(质子速度)首次提出,法线方向的速度沿着剪切方向(磁场变化最大、中间)具有量级为几十公里的速度剪切。 到目前宇宙线的起源没有定论。被认为是它的点源模型有:太阳、超新星爆发、白矮星和脉冲星(告诉旋转的中子星)等。由于引力引起的塌缩使白矮星和脉冲星演化为黑洞。黑洞也存在辐射机制,它简单可概括为:在黑洞的视界处当真空产生的粒子对时,负能量的例子会被黑洞吸收,正能量的粒子就能辐射出去。这种辐射可能成为宇宙线的一个源。本文我们利用求解视界附近狄拉克方程,计算了Vaidya-Bonner-de Sitter黑洞的Hawking温度和辐射谱。发现在黑洞的视界附近的确辐射Dirac粒子,这种辐射可能成为某种能量的宇宙线的源。同时,我们研究了一下黑洞的另外一些热力学性质。利用改进后的计算黑洞熵的brick-wall模型,计算了带电非稳态黑洞Vaidya-Bonner黑洞的熵,得到它的熵仍然与其世界面积成正比。更多还原

【Abstract】 In this thesis, with ESA’s Cluster data, we analyze the little scale structures of magnetopause boundary layers and study a possible source model of cosmic rays .Chen’s numerical simulation research finds that when the transverse flow is not homogeneous, magnetic field lines are to be forced bent and reconnection occurs in formerly identical magnetic field directed region during the impacting period, and a new "Reverse K" pattern reconnection configuration is formed in the current sheet region. On the normal vector, the magnetic field has multi-polar structure.Magnetopause boundary layer is always impacted by the solar wind from the bow shock. So, we can suppose on the local normal vector of magnetopause there are velocity shear, and the magnetic field also has multi-polar structure similar to the numerical simulation. Using the magnetic field data detected by FGM on CLUSTER, we determine the normal vector when Cluster satellites past through the magnetopause region on Feb 20, 2001 with Minimum Variance analysis method. We found on the local normal vector, the detected magnetic field has multi-polar structure. Also using proton bulk velocity detected by CIS, we calculated the velocity shear on the normal vector and it is about tens of kilometer per second.Up to now, there are not definite source models of cosmic rays though they come from the Sun, supernovas’ explosion, the white dwarfs and pulsars,et al.Because of gravity, the white dwarfs and pulsars collapse to black holes. There is a radiation mechanics at the event horizons of black hole. It is that at the event horizons of a black hole, there are vacuum particle pairs and the negative particles is absorbed by the black hole as the positive one runs away. This radiation possibly is a sourceof cosmic rays. Using DIRAC equation near black-holes’event horizon, we calculate the temperatures of Vaidya-Bonner-de Sitter black hole and its radiation spectrum. It is shown that near the event horizons, there are Dirac particles. At the same time, we study other thermodynamic charaters of the black hole. Via the improved brick-wall model proposed by t’ Hooft in 1985, we calculate the entropy of charged non-stationary Vaidya-Bonner black hole and conclude that the entropy is proportional to its horizons.更多还原