Measurement of the inelastic branch of the O-14(alpha, p)F-17 reaction: Implications for explosive burning in novae and x-ray bursters

A measurement of the inelastic component of the key astrophysical resonance in the 14O(α,p)17F reaction for burning and breakout from hot carbon-nitrogen-oxygen (CNO) cycles is reported. The inelastic component is found to be comparable to the ground-state branch and will enhance the 14O(α,p)17F reaction rate. The current results for the reaction rate confirm that the 14O(α,p)17F reaction is unlikely to contribute substantially to burning and breakout from the CNO cycles under novae conditions. The reaction can, however, contribute strongly to the breakout from the hot CNO cycles under the more extreme conditions found in x-ray bursters.

Possible magnetic and antimagnetic rotations in Dy-144

High spin states of Dy-144 have been studied through in-beam gamma-ray spectroscopy by using the reaction Mo-92(Fe-56,2p2n). It has been found that the continuation of the ground-state band forks into three Delta I=2 bands above the 8(+) state. This forking has been attributed to the alignments of pi h(11/2)(2) or nu h(11/2)(-2) configurations with the help of the systematics in neighboring nuclei. Additionally a negative-parity sideband of Delta I=2 cascades has been observed to start from the 5((-)) state and continue to a dipole band above the (13(-)) state through another negative-parity sideband of Delta I=2 cascades in between. These structures have been discussed from the viewpoint of a competition between "Magnetic Rotation" and "Anti-magnetic Rotation" based on a classical particles-plus-rotor model.

Measurement of the inelastic branch of the stellar O-14(alpha,p)F-17 reaction occurring in the explosive burning in Novae and X-ray busters

The inelastic component of the key astrophysical resonance (1(-), E-x=6.15 MeV) in the O-14(alpha,p)F-17 reaction has been studied by using the resonant scattering of F-17+p. The experiment was done at REX-ISOLDE CERN with the Miniball setup. The thick target method in inverse kinematics was utilized in the present experiment where a 44.2 MeV F-17 beam bombarded a similar to 40 mu m thick (CH2)(n) target. The inelastic scattering protons in coincidence with the de-excited 495 keV gamma rays have been clearly seen and they are from the inelastic branch to the first excited state in F-17 following decay of the 1(-) resonance in Ne-18. Some preliminary results are reported.

94.5Mev ~(14)N+~(59)Co反应系统准弹及深度非弹研究

通过对94.5 Mev ~(14)N+~(59)Co反应数据的处理，得到了Li-Ne产物出射的wilczynski图、角分布、电荷分布，并对它们做了一些常规的分析工作。在Feldmeier模型框架下对该系统作了经典轨道动力学计算，给出了计算结果并对它们做了说明。本工作为轻系统低轰击能量下周边碰撞的系统性研究提供了一些参考数据

~(14)N+~(51)耗散碰撞研究

本文主要研究了~(14)N+~(51)V(E_n = 94.6 MeV, 86.83 MeV, 79.2 MeV)的耗散碰撞，是上述系统性研究工作的一个重要组成部分。对N＋~(51)V系统的DIC反应作了比较详细的研究，给出了类弹产物质心系维辛斯基图，不同出射道及不同TKEL下的角分布，以及不同TKEL不的电荷分布。从这些实验结果中提取全弛豫动能，相互作用时间，及电荷分布的一次矩，二次矩。讨论了~(14)N+~(51) 耗散碰撞随相互作用时间的推移的演化过程，定性分析了壳效应对N＋V反应中电荷漂移的影响。同时还指出N＋V反应中α集团效应的影响是不重要的，为~(16)O+~(27)Al 研究中提出的强α集团效应对其DIC过程有影响这一观点提供了旁证。最后提取了准弹截面，DIC截面，从而导出全熔合截面，讨论了DIC反应对轰击能的依赖关系

~(14)C-菲在营养液-火山石-小麦有控系统中的迁移和转化

利用放射性同位素示踪技术研究了１４Ｃ标记菲在有控系统中的迁移转化．结果表明，１４Ｃ菲在有控系统中降解较快，施入药品２４ｄ后仅有０．３２％的１４Ｃ－菲存留在植物、营养液和火山石中．植物吸收的１４Ｃ放射性大部分被结合到植物组织中，其它１４Ｃ主要以菲的极性代谢物形态存在．

Vc二步发酵新组合菌系B_(15-14)的筛选及其条件优化

筛选出了一组Vc二步发酵的新组合菌系(命名为B15-14),研究了环境因子对新菌系产酸的影响。结果显示:新组合菌系的最适底糖浓度为7%;温度为29~33℃,31℃为最适;适当增加通气量(20~30 mL装液量,250 mL三角瓶)有利于产酸;起始pH值范围为6.0~7.5;以B t菌做伴生菌时,发酵40 h就已达到终点,明显缩短了发酵时间。

Sr_4Al_(14)O_(25)∶RE~(3+)(RE=Eu,Ce,Tb)中稀土离子的发光性质

采用高温固相反应合成了Sr4Al14O25∶RE3+(RE=Eu,Ce,Tb)样品,研究了其中Eu3+,Ce3+和Tb3+的光谱性质,以及Ce3+与Tb3+共掺时的能量传递现象;发现Eu3+,Ce3+和Tb3+占有两个格位,与Eu2+在此基质中的情况相似;在Tb3+的发射光谱中同时观察到了来自5D3与5D4的发射,表明两能级间无辐射跃迁过程不显著;Ce3+对Tb3+有敏化作用。

Synthesis and evaluation of novel polysaccharide-Gd-DTPA compounds as contrast agent for MRI

Macromolecular conjugates of two kinds of natural polysaccharides, that from Panax quinquefolium linn (PQPS) and Ganoderma applanatum pat (GAPS), with gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) have been synthesized and characterized by means of FTIR, elementary analysis and ICP-AES. Their stability was investigated by competition study with Ca2+, EDTA (ethylenediaminetetraacetic acid) and DTPA. Polysaccharide-bound complexes exhibit T-1 relaxivities of 1.5-1.7 times that of Gd-DTPA in D2O at 25degreesC and 9.4T. MR imaging of Sprague-Dawley (SD) rats showed remarkable enhancement in rat liver and kidney after i.v. injection of these two complexes: liver parenchyma 60.9+/-5.6%, 57.8+/-7.4% at 65-85 min; kidney 144.9+/-14.5%, 199.9+/-25.4% at 10-30 min for PQPS-GdDTPA, GAPS-Gd-DTPA at gadolinium dose of 0.083 and 0.082 mmol/kg, respectively. Our preliminary in vivo and in vitro study indicates that the two kinds of polysaccharide-bound complexes are potential tissue-specific contrast agents for MRI.

Morphology and structure of nylon-2,14 single crystals from dilute solution

A perfect single crystal of nylon-2,14 was prepared from 0.02% (w/v) 1,4-butanediol solution by a "self-seeding" technique and isothermal crystallization at 120 and 145 degreesC. The morphology and structure features were examined by transmission electron microscopy with both image and diffraction modes, atomic force microscopy, and wide-angle X-ray diffraction (WAXD). The nylon-2,14 single crystal grown from 1,4-butanediol at 145 degreesC inhabited a lathlike shape with a lamellar thickness of about 9 nm. Electron diffraction and WAXD data indicated that nylon-2,14 crystallized in a triclinic system with lattice dimensions a = 0.49 nm, b = 0.51 nm, c = 2.23 nm, alpha = 60.4degrees, beta = 77degrees, and gamma = 59degrees. The crystal structure is different from that of nylon-6,6 but similar to that of other members of nylon-2Y.

La_(1-x)Pr_xP_5O_(14) 晶体的光谱性质

分析了室温下晶体在紫外、可见区的吸收、荧光和红外光谱,利用Judd Ofeld理论计算了PrPP和La0.2Pr0.8PP晶体中Pr3+的实验振子强度,PrPP和La0.2Pr0.8PP晶体中Pr3+离子振子强度变化不大,说明在该晶体中Pr3+的浓度猝灭效应较小。红外光谱和结构分析确定了晶体的结构为单斜晶系,并观察到Pr3+的3P0 3H6跃迁的红色发射很强。

La(1-x)Pr_xP_5O_(14)晶体的研究

用水热法研究了La12xPr xP5O14(LaPrPP)(0 < x < 1,原子百分含量)晶体的生长,测定了La0.2Pr0.8PP晶体结构为 单斜晶系,空间群为P21/c。晶体的密度为3.27g/cm3,分解温度为915℃。分析了室温下晶体在紫外、可见区的吸 收、荧光和红外光谱,利用Judd2Ofeld 理论计算了PrPP 和La0. 2Pr0. 8PP 晶体中Pr3 + 的实验振子强度,得到一些规律性结果,观察到Pr3 + 的3 P0 —3 H6 跃迁的红色发射很强。