Shears mechanism in two-dimensional cranking relativistic mean field approach

Using the new two-dimensional cranking relativistic mean field (RMF) approach, the shears mechanism of magnetic rotation based on configuration πh121/2νh-211/2 in 142Gd is microscopically and self-consistently examined by investigating the aligning angular momenta of the valence nucleons.     

Shears mechanism in two-dimensional cranking relativistic mean field approach

Using the new two-dimensional cranking relativistic mean field (RMF) approach, the shears mechanism of magnetic rotation based on configuration πh²_11/2⊙νh^－2_11/2 in ¹⁴²Gd is microscopically and self-consistently examined by investigating the aligning angular momenta of the valence nucleons.     

近太阳17颗年轻恒星锂丰度: 丽江1.8 m望远镜高色散光谱观测

应用中国科学院云南天文台丽江天文观测站1.8 m望远镜及其折轴光谱仪,对18颗近太阳样本恒星进行了高色散光谱观测,获得这些恒星高质量的高色散光谱。表明原中国科学院国家天文台兴隆观测站2.16 m折轴光谱仪搬迁、改造获得成功,达到并超过了预期的效果。以丽江天文观测站1.8 m望远镜及其折轴光谱仪观测获得的高质量的高色散光谱为基础,应用高斯拟合方法测量了样本中17颗年轻类太阳恒星锂吸收线的等值宽度,并计算了锂元素丰度。应用Hall给出的经验公式,计算了这些年轻恒星的Ca ⅡΗ和Κ(λ=395.0 nm)辐射强度。讨论了锂元素丰度和表明恒星色球活动的Ca H和K线辐射强度之间的关系。发现锂元素丰度值高的年轻恒星,其Ca H和K线辐射更强。考虑到恒星自转速度随恒星年龄的变化,小质量主序前恒星随着恒星年龄的增加,自转明显的加快;主序恒星随着恒星年龄的增加,自转逐渐变慢。我们的结果支持恒星自转越快,其活动性也就越强,以及色球活动较强的恒星具有高的锂元素丰度值。     

Nuclear Current and Magnetic Rotation

The magnetic rotational bands based on the configuration πh11/2^2 vh11/2^-2 in ^142Gd are investigated with the newly developed tilted axis cranking relativistic mean field （RMF） theory with and without nuclear current. The effect of the nuclear current is discussed by comparing the total Routhians, single particle levels, electromagnetic transition probabilities B（M1） and B（E2） in self-consistent tilted axis cranking RMF caIculation with those obtained without the nuclear current. The nuclear currents are found to play an important role in the magnetic rotation of nuclei.