电子与类铍N3+和O4+离子碰撞激发截面的相对论扭曲波计算

采用全相对论扭曲波方法,系统地计算了类铍N³⁺和 O⁴⁺离子从基态到2s2p和2p² 的各激发态以及从亚稳态到2p²各激发态的电子碰撞激发截面,详细地讨论了靶态的关联效应对激发截面的影响.结果表明：对于2s-2p的单电子激发,在低能碰撞时,靶态的电子关联效应起非常重要的作用,且使得激发截面降低;而高能碰撞时,靶态波函数的描述对连续态波函数的影响比较小,对激发截面影响也比较小.对于2s²-2p²的双电子激发,其中基态2s²¹S₀到J=0的2p²³P₀,¹S₀的激发截面较大,其主要原因是末离子态波函数与基组态波函数的混合,但是其他几个激发的激发截面较小. 关键词： 全相对论扭曲波方法 电子碰撞激发 电子关联效应     

HIRFL辐照终端照射野均匀度与离子通量的关系

采用固体核径迹探测器聚碳酸脂膜,测定了兰州重离子研究装置提供的55MeV/u40Ar和80MeV/u20Ne离子束经辐照终端束流均匀化扫描装置后照射野均匀度与离子通量之间的关系.结果表明:对于40Ar和20Ne离子束,离子通量小于1×106和2×107ions/cm2时,横向照射野均匀度缓Ne离子束照射慢增加;当离子通量分别介于1×106—1×107和2×107—1×108ions/cm2时,40Ar和20野均匀度逐渐增加;离子通量达到1×107和1×108ions/cm2时,40Ar和20Ne离子束照射野均匀度分别约为58%和61%.从而说明,辐照终端束流扫描装置对束流的均匀化程度目前并不能满足辐照生物效应、辐射育种和重离子治癌等研究工作的需要,须对其性能做进一步的提高. Using 55 MeV/u 40Ar and 80 MeV/u20Ne ion beams delivered by the Heavy Ion Research Facility at Lanzhou (HIRFL), the relationships between the irradiation homogeneities in irradiation fields generated by the beam scanning device located at the irradiation terminal of the HIRFL and ion fluence were measured respectively with 100 μm polycarbonate films by means of nuclear track detection. The results show that the homogeneity increases when the ion fluence are lower than ........     

重离子束在诱变育种和分子改造中的应用

重离子束具有与中性辐射X,γ和中子不同的特性,利用这些特性开展它在生物学领域内的应用和基础研究具有重要的理论和实际意义.简要阐述了这种应用的理论基础,以及多年来实践的一些工作与取得的结果. Heavy ion beams have different character from X, γ rays and neutrons. It has important value in theory and practice to use the character to carry out application and fundamental researches in biological field. Theoretical basis of the application and some practice and their results are briefly described here.     

高价碘试剂的有机电化学合成及应用研究进展

芳基碘化物的阳极氧化是一种绿色高效的用于合成高价碘试剂的方法,该方法用电流代替了化学试剂,避免了使用价格昂贵、反应后处理棘手的氧化剂,如m-CPBA, H_2O_2, Oxone, Selectfluor等.利用电化学合成的高价碘试剂,既可促进氟化、氧化环化等反应,也可成功地应用于天然产物的全合成.一价碘/三价碘氧化还原体系可用来高效地形成碳碳键、碳杂原子等化学键.此外,能回收循环再利用的芳基碘介质可用于间接阳极氟化,且容易和产物分离.总结近年来高价碘试剂的电化学合成方法及其介导的各种化学反应.     

Electron impact excitation rate coefficients of N II ion

This paper calculates the electron impact excitation rate coefficients from the ground term 2s²2p^{2 3}P to the excited terms of the 2s²2p², 2s2p³, 2s²2p3s, 2s²2p3p, and 2s²2p3d configurations of N II. In the calculations, multiconfiguration Dirac--Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.     

甘肃当归新品系DGA2000-02的选育研究

当归新品系DGA2000 02是采用重离子束55 MeV/u 40Ar+15 离子辐照甘肃当归90 01干种子, 按新品种选育程序多年选育而成的。 2005—2007年, 在定西市岷县、 渭源县、 漳县、 陇西县等地当归品系区域试验中, 甘肃当归DGA2000 02平均产鲜当归10 621.5 kg/hm2, 较对照品种（甘肃当归90 01）平均增产鲜当归1 386.0 kg/hm2, 增产率15.0%。 生育期790 d, 茎秆深紫色, 根系黄白色。 测定结果: 总灰分4.2%, 酸不溶性灰分0.4%, 分别优于对照品种16%和33.3%; 浸出物61.4%, 较规定指标提高4.4%; 阿魏酸0.148%, 较规定指标提高2.96倍。 质量显著优于对照品种和2005年版《中国药典》规定指标。 适宜在海拔2 000—2 600 m 、 年降水量500—600 mm的二阴及高寒阴湿生态区栽培。 Angelica sinensis（Oliv）Diels new strain DGA2000 02 was selected successfully by Institute of Modern Physics, Chinese Academy of Sciences, Dryland Farming Research and Extension Center of Dingxi Prefecture, etc. According to the program of new strain selection, this new strain was selected for several years after the dry seeds of Gansu Angelica sinensis（Oliv）Diels 90 01 was irradiated by ions of 55 MeV/u 40Ar+15. During the period of year 2005—2007, region experiments of Angelica sinensis（Oliv）Diels new strain DGA2000 02 were developed in Minxian, Weiyuan, Zhangxian and Longxi etc. Average yield of the fresh DGA2000 02 Angelica was 10 621.5 kg/hm2, and 15.0% production was increased more than control (for 1 386.0 kg/hm2 of 90 01).The growth stage of the DGA2000 02 was 790 d, and it has deep purple stem and yellow white root. The quality analysis results are as follows: total ash content is 4.2% and acid fast ash content is 0.4%, 16% and 33.3% better than control, respectively; the lixivium is 61.4%, i.e., 4.4% more than the standard of Pharmacopoeia of People’s Republic of China (2005 edition); the ferulic acid content is 0.148%, i.e., 2.96 times ligher than the standard. All these results showed that the quality of the DGA2000 02 was better significantly than both control and the standard. It can be grown appropriately at the high, cold and dankness regions at the altitude of 2 000—2 600 m and with a annual precipitation of 500—600 mm.     

综合时序InSAR和GIS技术地面沉降时序演化规律研究

长期超量开采地下资源、动静载荷逐年增加均在一定程度上影响着区域地面沉降的发生与发展,选取覆盖北京平原地区29景Envisat ASAR数据,采用融合永久散射体(PS)和小基线合成孔径雷达干涉测量技术,获取区域地面沉降时序监测信息。结合GIS空间分析方法,在区域浅表层空间(地铁、城市密集建筑群(CBD)、立体交通网络设施)不同的利用模式下,选取5个典型地面沉降区域,结合土地利用分类信息、多光谱遥感影像、地质资料等,分析时间序列的不均匀沉降的演化规律。结果表明：浅地表空间利用的复杂情况在一定程度上影响着区域的不均匀沉降态势,空间利用情况越简单,沉降的梯度相对越小,不均匀沉降趋势越小。     

UHF-ALGEBRAS AND *-ISOMORPHISMS

The following problem is discussed: If μ is an AF-algebra, A and B are two C-algebras, x(A) and x(B) are the unit balls of μ A and μ B respectively, and there is an affine isomorphism from X(A) onto x(B), when are A and B isomorphic? This problem was inspired by K-theory of C*-algebras. If μ is a UHP-algebra of type {m~p}, an orientation on x(A) and x(B), i. e., an action of the special group of μ, is introduced. Then it is obtained that if the affine isomorphism commutes with the group action then A and B are isomorphic.     

静电场中的α-LiIO_3单晶沟道效应实验

自从杨桢等发现在静电场中α-LiIO3单晶的中子衍射[1]有异常现象以来,我国科学工作者对α-LiIO3相继进行了在静电场作用下的介电常数[2]、光的衍射[3]、X射线衍射[4]等方面的研究,都发现了不同程度的异常现象[5].理论工作者也进行了相应的研究.目前倾向性的看法是,认为这种异常     

重离子束定点诱变育种初探

介绍了在兰州重离子加速器上采用 75 Me V/u16O8+离子进行了贯穿与定点注入的实验 ,以及不同注入部位的种子在实验室萌发的根尖细胞染色体的微核率和畸变率与大田培育结果随剂量的变化情况 .经过 3年 5代 (南繁加代 )的系统选育 ,筛选出增产、矮杆、抗 (锈 )病、抗干热风和早熟等 9个稳定突变系.Penetration and site chosen implantation of spring wheat seeds at HIRFL with 75 MeV/u 16 O 8+ ions were caried out. The seeds, of which the different sites ware implanted by the ions were germinated in room. The frequency of micronuclei and chromosome aberration in their root tip cells was observed. The results of their cultivation in the field were different. Through selection of three year five generations (adding a generation in southern China each year), nine stable...