V-F变换在激光物理实验中的新型应用

介绍了一套十分适合应用于准连续激光物理实验的变换装置。该套装置不但可以将热电偶激光功率计输出的直流型模拟电压量变换成计数脉冲输出,还可以对光离子引起的、探测器给出的脉冲型模拟电压量进行累计变换。经过详细的模拟测试得知它变换激光功率的积分线性≤±0.015%,变换光离子脉冲信号的积分线性≤±0.23%。以上测试结果表明该套变换装置已经满足了一般激光物理实验的精度要求。

Liquid-liquid extraction of Pa-233(V) with Aliquat 336

The extraction of protactinium with Aliquat 336 (methyl-tri-caprylyl ammonium chloride) in toluene, cyclohexane and chloroform from HCl, HNO3, H2SO4, HClO4, HF and mixed HCl-HF media was investigated by radioactive tracer technique. Distribution ratios of protactinium between the aqueous solution and the organic phase were determined as a function of shaking time, concentrations of acid in aqueous solution phase, extractant concentration and type of diluents in the organic phase. Aliquat 336 can almost quantitatively extract protactinium from strong HCl solution. At the same time, small amounts of HF in HCl solutions have a strong effect on Pa distribution.

Solvent extraction study of protactinium(V) with methyl-iso-butyl carbinol and methyl-iso-butyl ketone

In order to study the extraction pattern of protactinium in different types of extracting agents and compare the similarity of patterns of extraction with dubnium and thereby unraveling its chemistry, solvent extraction of protactinium(V) with methyl-iso-butyl carbinol (MIBC) and methyl-iso-butyl ketone (MIBK) was studied using Pa-233 as a radiotracer. The extraction efficiencies of Pa were determined as a function of shaking time, concentrations of mineral acids, and extractant concentrations using the two extractants. The results show that MIBK is more suitable for the extraction of protactinium than MIBC in benzene. Furthermore, the effect of the F anion is also discussed.

Liquid-liquid extraction of protactinium(V) using tri-iso-octylamine

Solvent extraction of protactinium with tri-iso-octyl-amine (TIOA) in xylene, benzene, carbon tetrachloride and chloroform from HCl, HF, HNO3, HClO4 and H2SO4 media was studied using Pa-233 as a radiotracer. The extraction efficiencies of protactinium were determined as a function of shaking time, concentrations of mineral acids in aqueous phase, extractant concentrations and diluents in organic phase. The extraction mechanism was discussed. The results show that the extracted species in the organic phase is [(R3N-H)(n)Pa(OH)(x)Cl-y(5-x-y)].

Studying the Attribution of LiF in OLED by the C-V Characteristics

The organic light-emitting device (OLED) with simple structures of indium tin oxide (ITO)/tris(8-quinolinolato) aluminum (Alq(3))/LiF/Al and ITO/Alq(3)/Al was fabricated to analyze the contribution of LiF in OLED. We used the C-V characteristics to investigate the contribution of LiF in OLED and found that the capacitance of the above-mentioned structures was 12.5 nF and 77.5 nF, respectively. It is shown that the LiF layer affects the property of OLED resulting in the change of the capacitance of the device.

97MeV~(16)O + ~(51)V反应中α粒子发射机制研究

利用近物所1.7米回旋加速器加速出的97MeV的~(16)O束流轰击~(51)V靶，九组不同的望远镜系统用于对~(16)O + ~(51)V反应中击射α粒子进行单举测量及α粒子与类弹产物符合测量。所有的探测器组号通过电子学线路和近物原的MODAS 1数据获取系统以事件方式记录在磁带上，实现了42参数同时获取。与此同时，利用所提供的束流，完成了CsI(Tl)晶体phoswich探测器的调试工作，得到了好的结果。在VAX/11-780计算机上用PAX数据分析程序对实验数据进行离线分析，得到了α粒子单举能谱、角分布，E-O平面内d~2σ/dEαΩ等高图和速度平面内d_2σ/PCdEdΩ截面等高图；得到了复合核蒸发和直接α粒子发射的截面值。同时也得到了α粒子——类弹产物符合的α粒子能谱和前方向击射α粒子与类弹产物符合的两维能量联图。为了对直接机制中予平衡发射α粒子的贡献有一估计，用激子模型对~(16)O + ~(51)V反应系统进行了理论计算，得到了复合核蒸发及予平衡发射α粒子产额占总产额中所占的比份。实验结果和理论分析表明：除复合核蒸发和予平衡发射的贡献外，还有其它反应机制的存在。通过二体和三体运动学对所得到的符合实际数据进行分析，证明了类弹、类靶跟随发射和弹核破裂(break-up)机制的存在。综合所有的实际结果，我们认为：~(16)O + ~(51)V反应系统中α粒子主要采源于复合核的蒸发和予平衡发射机制，除此而外还应包括类弹、类靶发射和弹核破裂等反应机制的贡献

Effects of reaction conditions on the selective oxidation of propane to acrylic acid on Mo-V-Te-Nb oxides

An effective Mo-1 V(0.3)Te(0.23)Nb(0.12)Ox catalysts for the selective oxidation of propane to acrylic acid was successfully prepared by using rotavap method. The catalyst was characterized by XRD and shown to contain (V0.07Mo0.93)(5)O-14, (Nb0.09Mo0.91)O-2.8,3MoO(2)(.)Nb(2)O(5), Mo5TeO16 and/or TeMo4O13, Te4Nb2O13 and a new TeMO (TeVMoO or TeVNbMoO; M = Mo, V and Nb) crystalline phase as the major phase. Regardless of the intrinsic catalytic characteristics of the catalyst, the external reaction conditions would have strong effects on the catalytic performance for propane oxidation. So in this paper, the effects of reaction conditions were investigated and discussed, including temperature, space velocity, V(air)/V(C3H8) ratio and V(steam)/V(C3H8) ratio. A stability test was also carried out on Mo1V0.3Te0.23Nb0.12Ox catalyst. The experimental run was performed during 100 h under the optimized reaction conditions. During the 100 h of operation, propane conversion and acrylic acid selectivity remained at about 59 and 64%, respectively. (C) 2004 Elsevier B.V. All rights reserved.