Mg原子3p3/2nd系列自电离分支比的研究

利用多通道量子亏损理论(MQDT),结合已知的K矩阵,研究了受实验条件限制目前无法得到的Mg原子3p3/2nd(J=1,3)系列的自电离分支比,同时对3pnd系列的部分自电离光谱作了计算,并取得了和实验比较吻合的结果。结合分支比研究结果探讨了Mg原子的能级结构特点及粒子数反转的可能性     

Inverstigation of Self-Starting for Self-Mode-Locked Ti:Sapphire Laser

ＩｎｖｅｒｓｔｉｇａｔｉｏｎｏｆＳｅｌｆ－ＳｔａｒｔｉｎｇｆｏｒＳｅｌｆ－Ｍｏｄｅ－ＬｏｃｋｅｄＴｉ：ＳａｐｐｈｉｒｅＬａｓｅｒＩｎｖｅｒｓｔｉｇａｔｉｏｎｏｆＳｅｌｆ－ＳｔａｒｔｉｎｇｆｏｒＳｅｌｆ－Ｍｏｄｅ－ＬｏｃｋｅｄＴｉ：ＳａｐｐｈｉｒｅＬａ...     

The Hoyle state in nuclear lattice effective field theory

We review the calculation of the Hoyle state of ¹²C in nuclear lattice effective field theory (NLEFT) and its anthropic implications in the nucleosynthesis of ¹²C and ¹⁶O in red giant stars. We also analyse the extension of NLEFT to the regime of medium-mass nuclei, with emphasis on the determination of the ground-state energies of the α nuclei ¹⁶O, ²⁰Ne, ²⁴Mg, and ²⁸Si by Euclidean time projection. Finally, we discuss recent NLEFT results for the spectrum, electromagnetic properties, and α-cluster structure of ¹⁶O.     

非等时变分与拉格朗日方程

在理论力学的教学中,基于最小作用量原理推导拉格朗日方程的时候,一般假设了等时变分的条件.本文在非等时变分的条件下重新推导了拉格朗日方程,并解释了非等时变分的物理含义.     

费米子Regge轨迹的解析性和阈行为

从π介子核子散射振幅出发,根据Mandelstam表示和么正条件,对于奇异量子数为零、重子数为1的费米子Regge轨迹,求得了下列结果:(1)位置参数α(s)的解析性,只有右方物理割而无左方动力割,但是左方有从s=0到-∞的运动学割。(2)当s<0时α(s)取复数值,并且还有一条同它成复共轭(在s<0范围内)的Regge轨迹。这一对轨迹它们的J-宇称相同,但是空间宇称相反。02时,α(s)为实数。不同宇称的轨迹对s的依赖不同。(3)讨论了费米子Regge迹在阈能(W₀=M+μ)附近的行为。凡是与共振态、束缚态有关的Regge轨迹,α(W₀)≠0。求得了在阈附近的表示,定性方面同玻色子轨迹相同。(4)还有一大类Regge轨迹,它们同共振态、束缚态无关,α(W₀)=0。这类轨迹在能量趋近阈能时,有无穷多个极点趋于ReJ=0(即我们在费米子情况下得到Gribov-Pomeranchuk极点凝聚现象),这类轨迹当能量由阈下趋于阈时,从J平面左半平面共轭成对趋于ReJ=0;当能量从阈上趋于阈时,成对地从第一和第三象限趋于ReJ=0。所有这些极点实数部分Reα→0比虚数部分Imα→0快一或二个数量级。J平面原点是一个凝聚点,这类“非动力”的Regge轨迹阈行为,无论对玻色子、费米子,以至非相对论势散射,定性都相似(只是凝聚的轴线和点不同)。它们实际上是s矩阵在阈的普遍性质的反映。     

Topological Analysis on Intermolecular Interaction of Two Ferromagnetic Organic Radical Compound

Electron density studies of two organic radical species, para-nitronyl-4-benzylideneamino-2,2,6,6-tetramethylpiperidin-1-oxyl, 1, and para-bromide-4-benzylideneamino-2,2,6,6-tetramethylpiperidin-1-oxyl, 2, have been carefully investigated by X-ray diffraction method at low temperature( 125 K and 100 K). They crystallized in the space group of Pnma and P21/c respectively. No phase transition is detected at the temperature range studied. Electron density distribution based on Multipole model will be presented. Electron density accumulation and the delocalized □-character found at C-C bonds of the benzene ring.     

Applied Physics A 52, no. 5 (1991)

Applied Physics A 52, no. 5 (1991)