U(Ⅳ)-U(Ⅵ)同位素交换反应动力学研究 Ⅰ.Fe~(2+)对U(Ⅳ)-U(Ⅵ)同位素交换反应的催化作用

一、前言由于U(IV)-U(VI)同位素交换体系具有相当大的同位素效应和很好的稳定性,并且容易实现两相回流,这对于分离U同位素的工业应用都是十分有利的。但是,U(IV)-U(VI)同位素交换反应速度非常慢,常温下H~+浓度为1.0—4.0 mol/l时,速度常数为1.0×10~(-4)l~2/mol·s。因此要用U(IV)-U(VI)交换体系浓缩铀同位素,必须研究U(IV)-U(VI)交换反应动力学,找到加快交换反应的方法。     

溶剂萃取分离锂同位素研究Ⅱ.苏丹Ⅰ-中性配位体协萃体系萃取分离锂同位素效应探讨

文章讨论了苏丹I-中性配位体协萃体系萃取分离锂同位素中螯合剂和协萃剂的结构效应。为了获得高的同位素分离效应,螯合剂必须是弱酸性的(PK_α>11),具有强的分子内氢键及易于形成六元螯合环。协萃剂结构不仅要求无空间位阻,而且具有强的配位基。α随配位基的碱性增大而相应提高。萃取络合物中螯合环的增多亦有利于体系α的提高。此外本文还讨论了一些萃取体系的同位素富集方向和萃锂体系用于分离同位素的前景。     

石油系油浆与煤系闪蒸油的焦化性能——I．热解条件的影响

通过偏光显微镜观察了石油系油浆（LH）与煤系闪蒸油（SN）焦化后所得焦块的光学结构。结果表明，在较宽条件下两种原料单独焦化均得不到取向度高的流线型结构。将两种原料以一定比例混合后先热解丙焦化所得焦块的光学结构明显好于二者混合后直接焦化所得焦块的光学结构，其中LH和SN以3：2的重量比混合后在440℃、1MPa下热解3．5h然后再在530℃、1MPa下焦化8h所得焦块为具有较高取向度的流线型结构，适合于作为针状焦的起始原料。     

硫脲型整合树脂在分析上的应用 Ⅰ.岩样中微量银的中子活化分析

前言银和其他贵金属元素一样,在地壳中比较稀少,按其自然丰度为第67号元素,平均含量仅0.07 ppm。由于地质样品成分非常复杂,为测定其微量银,必须进行严格的化学分离。但是迄今文献中报道的许多分离分法,步骤都相当冗长,一般采用氯化银反     

Fuel management of the HTR-10 including the equilibrium state and the running-in phase

The mode of fuel management of the HTR-10 was studied, including the simulation of the fuel shuffling process and the measurement of the burnup of a fuel element. The prior consideration was the design of the equilibrium state. Based on this the fuel loading of the initial core and the fuel shuffling mode from the initial core through the running-in phase into the equilibrium state were studied. The code system VSOP was used for the physical layout of the HTR-10 at the equilibrium state and in the running-in phase. For the equilibrium state, in order to lessen the difference between the peak and the average burnup, 5-fuel-passage-through-the-core was chosen for the fuel management. The average burnup of the spent fuel for the equilibrium core is 80 000 MWd t⁻¹, and the peak value of it is less than 100 000 MWd t⁻¹ when the burnup of the recycled fuel element is under 72 000 MWd t⁻¹. The mixture of fuel element and graphite element was used for the initial core loading, the volume fractions of the fuel and the graphite elements were 0.57 and 0.43, respectively. During the running-in phase, the volume fraction of graphite will decrease with the fresh fuel elements being loaded from the top of the core and the graphite elements discharged from the bottom of the core. The fuel shuffling mode is similar to that of the equilibrium state. The burnup limit of recycled fuel element is also 72 000 MWd t⁻¹ and the peak burnup is less than 100 000 MWd t⁻¹. Finally the core will be full of fuel elements with a certain profile of burnup and reaches the equilibrium state. According to the characteristics of the pebble-bed high temperature gas-cooled reactor, a calibrating method of concentration of ¹³⁷Cs was proposed for the measurement of fuel burnup.     

堤身的数据采集及断面设计的几点建议

针对堤防设计的基础资料采集和设计优化，提出了一些合理性建议。     

焊接史

本文追溯了19世纪末发明的电弧焊接的历史。当Oscar Kjellberg成立伊萨公司以探索他发明的涂层焊条时，伊萨从一开始就和电弧焊的发展结下了不解之缘。     

内嵌闪存MCU的高性能多通道24位采集系统ADuC845

ADuC845是ADI公司新推出的嵌有单指令周期8052闪存MCU、带两路24位∑ -△A/D、双12位D/A以及两个灵活脉宽调制输出的高性能24位数据采集与处理系统芯片。该芯片的数据处理速度达12MIPS,且设计简单 ,噪声低 ,非常适用于精密仪器仪表。文中详细介绍了该芯片的功能特点和工作原理 ,给出了该芯片的应用方法。     

SKYPE在远程英语教学方面的实时应用

SKYPE系统是目前世界上最流行的互联网远程视频、音频、文字实时交互平台，其音频、视频传播实时非常清晰，这对将远程教育拓展到家庭，特别是对推动远程英语教育的广泛性和普遍性能够起到很大的作用，本文就该平台的基本功能和性能做了介绍，并在远程英语教育方面的应用提出了实践的方法。     

Surface charge accumulation and decay on a spacer stressed with DC voltages at atmospheric conditions

Contents Surface charge accumulation and its decay at a GIS spacer are studied at atmospheric conditions employing a two step-calibration method. The results show that the accumulation saturates within 30 minutes; the dominant mechanism of surface charge accumulation is the drift of charged particles via air, while that of the decay is surface conduction. The characteristics are similar at both polarities.

---

Sättigungskonzentration und Abklingverhalten der Oberflächenladung an einem mit Gleichspannung beanspruchten Abstandshalter unter atmosphärischen Bedingungen

Übersicht Die Konzentration und das Abklingen von Oberflächenladungen an einem GIS Abstandshalter wurden unter atmosphärischen Bedingungen mit Hilfe eines zweistufigen Kalibrierungsverfahrens untersucht. Die Ergebnisse zeigen eine Sättigung der Ladungskonzentration innerhalb von 30 Minuten. Als Hauptursache der Ladungskonzentration ist die Drift geladener Teilchen in Luft anzusehen, während das Abklingen auf die Oberflächenleitung zurückzuführen ist. Ähnliche Charakteristiken ergeben sich mit beiden Polaritäten.