R-矩阵模型拟合中的误差传递

对⁷Li, ¹¹B和¹⁷O系统的R-矩阵模型拟合进行了系统的误差传递特性研究; 揭示了一些误差传递的规律, 建立了可用于描写标准误差传递的经验关系式, 确定了评价标准截面⁶Li(n, α), ¹⁰B(n, α₀)和¹⁰B(n, α₁)最可能的误差范围.     

R矩阵模型拟合中的协方差传递

对⁷Li,¹¹B和¹⁷O系统的R矩阵模型拟合进行了系统的协方差传递特性研究;揭示出部分协方差传递的规律性,发现系统误差的中程相关项在协方差传递中起到非常重要的作用     

中国评价核参数库和IAEA之推荐输入参数库

概述了为核反应模型计算用的“中国评价核参数库”的发展和结构 ,指出了该数据库在国际核反应数据模型计算的“推荐输入参数库”中的作用和地位 .目前正研制更新的CENPL ,一方面将检验、更新和扩充数据 ,特别注重研究适用于更高能区和非稳定核区的模型参数 ;另一方面发展其检索软件和网络软件 ,实现网络在线服务. The Chinese Evaluated Nuclear Parameter Library (CENPL) for the model calculations of nuclear reactions was developed in the past ten years. The International Atomic Energy Agency has constructed a Reference Input Parameter Library (RIPL) for the calculations of nuclear reaction data in the meantime. All data files of CENPL are adopted as the RIPL Starter Files. The model parameters estimated and recommended by our group are specially selected as recommended files. The updated CENPL is being developed...     

恒星氦燃烧关键反应12C(α,γ)16O天体物理S因子及其反应率

恒星氦燃烧阶段3α反应和12C（α,γ）16O反应相互竞争,两者的反应率共同决定了氦燃烧结束后12C与16O的丰度比,该比值是大质量恒星后继演化以及伴随的元素核合成过程的初始条件。目前,氦燃烧12C（α,γ）16O反应起始T₉=0.2处,天体物理模型要求的反应率的精确度要低于10%,然而尚未有实验或理论给出满足要求的结果。最为直接和可靠地获取12C（α,γ）16O反应率的方法,就是尽可能往低能区测量其天体物理S因子,然后通过理论外推到感兴趣的能区。为此基于经典的R-矩阵理论,建立了适用于低能核反应的多道、多能级的约化R-矩阵理论来拟合几乎所有可用的16O系统的实验数据。配合使用协方差统计和误差传播理论,拟合外推得到了客观的、内部自恰的和唯一性好的12C（α,γ）16O反应天体物理S因子。总的外推S因子STOT（0.3 MeV）=162.7±7.3 keV·b,理论上首次给出达到恒星演化与元素核合成模型的最低要求的S因子。基于计算给出的全能区的S因子,数值积分给出了温度位于0.04 6 T₉ 6 10的12C（α,γ）16O天体物理反应率。在T₉=0.2处,推荐的反应率为（7.83 ±0.35）×10-15 cm3mol-1s-1。During stellar helium burning, the rates of 3α and the 12C(α,γ)16O reaction, in competition with one another, determine the relative abundances of 12C and 16O in a massive star. The abundance ratio is the beginning condition of the following nucleosynthesis and star evolution of massive stars, which are extremely sensitive to the rate of 12C(α,γ)16O reaction at T₉=0.2. The most direct and trustworthy way to obtain the reaction rate of the 12C(α,γ)16O reaction is to measure the S factor for that reaction to as low energy as possible, and to extrapolate to energies of astrophysical interest. Based on a new multilevel and multichannel reduced R-matrix theory for applications in nuclear astrophysics, we have obtained an accurate and self-consistent astrophysical S factor of 12C(α,γ)16O, by a global fitting for almost all available experimental data of 16O system, with the coordination of covariance statistics and error-propagation theory. The extrapolated S factor of 12C(α,γ)16O was obtained with a recommended value STOT (0.3 MeV)=162.7±7.3 keV·b. And the reaction rates of 12C(α,γ)16O for stellar temperatures between 0.04 6 T₉ 6 10 are provided. At T₉=0.2, the reaction rate is (7.83 ±0.35)×10-15 cm3mol-1s-1, where stellar helium burning occurs.     

A new method to avoid PPP in data evaluation

The Peelle Pertinent Puzzle (PPP) has been studied systematically. The results obtained by using several proposed methods to deal with a sample of {}^6Li(n, t) are compared with each other. The cause of PPP occurrence has been found. A new method to avoid PPP is introduced, whose main idea is ‘to selectively make suitable correction for systematic error according to the relative extent of discrepancy'. The method is able to produce the best result and should be used to avoid the PPP at first.     

色散光学模型参数的评价与应用

仔细评价并介绍了几个可在核数据工作中直接应用的中重核色散光学模型参数．By careful analysis, the parameters of DOMA (Disperse Optical Model Analysis) for some medium and heavy nucleus are determined. These parameters are useful for the evaluation of nuclear data.     

208Pb平均振幅或形变参数系统研究及中子直接非弹性散射截面计算

对２０８Ｐｂ的低激发态分立能级属性和相关平均振幅或形变参数进行了系统研究,利用扭曲波波恩近似方法系统计算了１２个分立能级的中子直接非弹性散射截面． The amplitudes or form factors of the low discrete levels of 208 Pb are investigated systematically, the neutron direct inelastic scattering cross sections from 12 levels on 208 Pb are calculated.     

Error propagation with R-matrix model fitting

The error propagation features with R-matrix model fitting 7Li, 11B and 17O systems have been researched systematically. Some laws of error propagation have been revealed, an experience formula for describing standard error propagation has been established, and the most possible error range for evaluated standard cross section of 6Li (n, α), 10B (n, α) and 10B (n, α1) has been determined.     

低能核反应理论的研究与应用

介绍有关低能核反应理论的研究与应用工作．The work for research and application of low energy nuclear reaction theories is introduced.     

模拟海市蜃楼

本文是以极简单的实验设备,用人工的方法模拟海市蜃楼;对蜃景进行了拍照;应用激光蜃景的简单模型,对一个点光源的蜃景与成象介质折射率的分布关系进行了实验研究。并对这一物理现象作了实验的分析与说明。实验原理与装置光通过介质时,因其折射率的不同,会产生不同的偏折。筷子在水碗中折起;水下之物看起来浮浅。这些常见的现象与神奇的海市蜃楼现象在物理成因方面,并没有本质上的区别。它们都是由于介质对光的折射关系,使人眼产生错觉,物体的象在人们的视觉中形成了空间的偏移。