一种新的灵敏核探针——慢正电子束流装置

简要介绍了广泛应用于表面科学的灵敏核探针——慢正电子束设备的原理、构造和应用 ,阐述了北京慢正电子束流装置的设计原理和性能 ,讨论了北京慢正电子束流装置今后的研究前景. A novel and compact slow positron beam line——Beijing Slow Positron Beam Line was described. The basic physical concepts of the slow positron beam and its applications were reviewed. Recent experimental results showed the converting effcicency for the total positrons from the radioisotope to slow positrons was 8×10 -5 and the moderation efficiency was 1.7×10 -4 . The future development of Beijing Intense Slow Positron Beam, based on the BEPC LINAC, was also briefly discussed.     

REE bound polysaccharides in leaves of Dicranopteris dichotoma by MAA

Ｉｎｒｅｃｅｎｔｄｅｃａｄｅｓ,ｔｈｅｐｈｙｓｉｏｌｏｇｉｃａｌｆｕｎｃｔｉｏｎｏｆＲＥＥｓａｎｄｔｈｅｉｒｓｉｇｎｉｆｉｃａｎｃｅｏｎｌｉｖｉｎｇｂｅｉｎｇｓａｓｗｅｌｌａｓｔｈｅｉｒｌｏｎｇｔｅｒｍｂｉｏｌｏｇｉｃａｌｅｆｆｅｃｔｓｏｎｂｏｄｉｅｓｏｆｌｉｖｉｎｇｂｅｉｎｇｓｈａｖｅｄｒａｗｎｇｒｅａｔａｔｔｅｎｔｉｏｎ.ａｃｃｏｍｐａｎｉｅｄｂｙｔｈｅｅｘｔｅｎｓｉｖｅａｐｐｌｉｃａｔｉｏｎｏｆＲＥＥｓｉｎａｇｒｉｃｕｌｔｕｒｅ,ｍｏｄｅｒｎｉｎｄｕｓｔｒｙａｎｄｍｅｄｉｃｉｎｅ.Ｈｏｗｅｖｅ…     

分子活化分析研究铁芒萁叶中稀土结合多糖

利用分子活化分析技术初步研究了铁芒萁叶中稀土结合多糖的状态.铁芒萁叶经过提取和生化分离后,得到冷水溶性多糖,热水溶性多糖,酸溶性多糖和碱溶性多糖 将所得到的多糖脱蛋白后通过凝胶柱,比色法测定多糖的吸收曲线,并用中子活化法(NAA)测定多糖中的8个稀土元素(La,Ce,Nd,Sm,Eu,Tb,Yb和Lu)的含量.研究结果表明,铁芒萁体内稀土元素与多糖有紧密结合.经分子量测定,与稀土元素(REE)结合的多糖为小分子量多糖(1～2)×10~4u.