s＋d混合波对称性下计入库仑作用和Van Hove奇异性的超导转变…

本文在ｓ＋ｄ混合波对称性下研究了Ｖａｎ Ｈｏｖｅ奇异性、准粒子配对相互作用各向异性并再计入库仑排斥势对超导转变温度（Ｔｃ）和同位素效应的联合效应。结果表明，Ｖａｎ Ｈｏｖｅ奇异性和各向异性都能显著地增高Ｔｃ，库仑作用则降低Ｔｃ。库仑作用和Ｖａｎ Ｈｏｖｅ奇异性都能减小同位素效应指数（α），各向异性和ｄ波成分则增大α。计入库仑作用后α就随ＣｕＯ２面内各向异性参量增大而增大。由此可以推测，如果实验上肯     

测量铀同位素位移光谱的方法和装置

测量铀同位素的高分辨位移光谱,目前多采用原子束光谱法[1].该方法的分辨率和准确度高,但是设备复杂昂贵,操作复杂,特别是很难避免铀的高温腐蚀和放射性污染.近年来,美国 Los Alamos实验室的R.A.Keller等人[2]提出用光电流光谱法测量铀同位素位移光谱,并采用天然铀空心阴极灯测量了238U-235U的位移光谱.但是该方法由于同位素丰度相差悬殊,丰度高的同位素谱线强,丰度低的谱线弱,严重影响测量的灵敏度与准确度.特别是使用的单光路测量系统还不能测量零位移光谱. 本发明的目的,在于改进光电流光谱法单光路系统测量铀同位素仕移光谱受同位素…     

Halo Effect on Direct Neutron Capture Process

We calculate the capture cross sections of the ^10Be(n,γ) ^11Be reaction by means of the asymptotic normalization coefficient method and demonstrate the halo effects on the capture cross sections for the direct radiative neutron capture where a p-, s- or d-wave neutron is captured into an s-orbit or p-orbit in ^11Be by emitting an E1 γ-ray, respectively. The result shows that the enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the ha/o, which is clearly illustrated by the reduced transition amplitude function.     

离子色谱分离法提纯异麦芽低聚糖

异麦芽低聚糖(IMO)具有显著的生理功能、低热量、安全无毒和结构稳定等特性,广泛应用于食品工业.本文尝试用强酸性苯乙烯系阳离子交换树脂对异麦芽低聚糖浆分离纯化,尽可能去除糖浆中的葡萄糖等成分,减少四糖以上成分,富集异麦芽低聚糖,提高产品的功能性.     

Measurement of hyperfine structure and isotope shifts in the 580.56nm line of 142－145,146,148,150Nd+

Isotope shifts and hyperfine spectrum of singly ionized neodymium ion was measured by collinear fast-ion-beam laser spectroscopy. The hyperfine A constants and B constants are obtained for the (23230)9/2^0 level and 4f^45d ^6K9/2 level, respectively. The optical isotope shifts between seven isotopes in the 580.56 nm of^142-145,146,148,150Nd^ line are determined. The configuration admixtures for (23230)9/2^0 level were quantitatively analysed to be 4f^46p, 4f^35d^2, and 4f^35d6p with mixing coefficients of 67%, 5%, and 28%, respectively.     

振动-转动相变的解析描述

本文用1/N展开技术,计算了Sm同位素的低能谱和E2性质,并与T.Otsuka等人的精确计算结果进行了系统比较,表明振动-转动相变可以用近似的解析方法描述.     

新重丰中子同位素239Pa

用50MeV/u ¹⁸O离子同天然铀靶反应产生了新重丰中子同位素²³⁹Pa.用放射化学法从反应产物中分离Pa活性,通过观测²³⁹Pa及子体²³⁹U衰变所得到的结果显示:首次合成和鉴别了新重丰中子核素²³⁹Pa,并测定出²³⁹Pa的半衰期为106±30min.