UF4在氧或湿氧中热化学反应研究

采用显微激光拉曼光谱技术、称重及形貌观察等手段,开展了UF₄在氧气或相对湿度93%湿氧气氛中的热化学反应实验研究,获取了UF₄不同温度时效后的质量、颜色及失重情况,以及反应前后不同铀化合物的拉曼光谱。结果表明：UF₄在氧气或湿氧中加热至200 ℃时,性质稳定,其拉曼光谱基本无变化;250~600 ℃时,样品表面颜色发生明显变化。拉曼光谱分析发现,在氧气气氛中有UO₂F₂、UO₂、U₃O₈,在湿氧气氛中有UO₂F₂、UO₂F₂•2H₂O、UO₂F₂•nH₂O、UO₂、U₃O₈等多种铀化合物生成。随着温度的升高,UF₄在氧气中的化学反应速率呈现由慢到快再到慢的变化趋势。     

国内外低能核理论的发展历史、现状和走势

大型核物理实验装置的问世和实验技术的进步,为核理论研究提供了越来越丰富的实验数据,检验着现有的理论,也为理论研究提出了新的课题,因而拓宽着核理论的研究领域。现代大型超级计算机的运算能力和运算速度的迅速提高以及数值计算方法的不断改进极大地提高了核多体计算的精确程度。核理论研究已进入了一个前所未有的迅速发展时期。本文就低能核理论的研究现状、国内近期主要研究进展和将来的发展趋势作简要分析和概述,并对核理论研究工作的今后发展提出了建议。     

Influence of Conductivity of Slag on Decarburization Reaction

By altering the electrochemical properties of slag, the decarburization reaction of Fe3+-based slag withFe-C droplet was studied. The results showed that a lot of free electrons and holes exist in the slag containing transition metal oxides (such as TiO2 and Fe2O3). So electronic conduction in the slag increases. Finally, it led to the increment of the decarburization reaction rate between slag and Fe-C droplet, and mass fraction of carbon remaining indroplet decreases to a lower level.     

~(19)F(p,αγ)~(16)O瞬发核反应测定茶叶中的含氟量

本文介绍了在400kV高压倍加器上,利用~(19)F(p,αγ)~(16)O瞬发核反应测量国内150余种茶叶样品含氟量的原理及实验装置,给出了一批典型的测量结果。结果表明:同一品种的茶叶,茶的品级数越大,含氟量越高;茶叶的品种越好,含氟量越低。     

An improved outer pipe method for expansive pressure measurement of static cracking agentsOA

Static cracking agent(SCA) is actively investigated as an alternative to explosive blasting for rock breakage due to its immense expansion property. SCA can eliminate the negative effects of shock, noise and harmful gases encountered in explosive blasting processes. Accurate measurement and deep understanding of the expansive properties of SCAs are important in their industrial application. An improved outer pipe method(OPM), termed the upper end surface method(UESM), is proposed in this paper t...     

一类反应扩散模型的未知参数辨识

考虑一类反应扩散模型的参数辨识问题，将原问题转化为最优化问题后，利用伴随状态方法，推导出控制方程组的伴随方程组，从而给出目标函数关于未知参数的下降方向计算公式。最后给出具体的算法，说明了该方法的可行性。     

2-（5-溴嘧啶偶氮）对苯二酚的合成及与金属离子显色反应

以2-氨基-5-溴嘧啶为原料,经重氮化后与对苯二酚偶联,合成2-（5-溴嘧啶偶氮）对苯二酚．用元素分析、波谱等鉴定其结构,并研究了它与Cu^2＋,Ni^2＋,Co^2＋,Cd^2＋,Ag^＋等金属离子的显色反应．结果表明,这些离子的摩尔吸光系数8达到2．56～8．23×10^4L·mol^-1·cm^-1.     

235U快中子核反应截面协方差评价

本文基于最小二乘不确定度传递方法,建立²³⁵U中子裂变核反应截面模型依赖型与非模型依赖型协方差评价体系。通过针对实验测量较丰富的中子反应总截面、辐射俘获、(n,2n)等核反应实验数据不确定度源项分析,为协方差评价提供实验基础,并给出对应核反应截面的非模型依赖型协方差评价数据。通过开展快中子能区²³⁵U核反应理论模型参数灵敏度计算与分析,导出实验测量缺乏的核反应截面模型依赖型协方差评价数据。经上述系统评价,所得协方差数据与核反应截面中心值研究过程自洽、物理合理,并按国际标准ENDF-6格式输出,便于核工程用户使用。     

Lithium Intercalation Compound Dramatically Influences the Electrochemical Properties of Exfoliated MoS2

MoS₂ and other transition metal dichalcogenides (TMDs) have recently gained a renewed interest due to the interesting electronic, catalytic, and mechanical properties which they possess when down‐sized to single or few layer sheets. Exfoliation of the bulk multilayer structure can be achieved by a preliminary chemical Li intercalation followed by the exfoliation due to the reaction of Li with water. Organolithium compounds are generally adopted for the Li intercalation with n‐butyllithium (n‐Bu‐Li) being the most common. Here, the use of three different organolithium compounds are investigated and compared, i.e., methyllithium (Me‐Li), n‐butyllithium (n‐Bu‐Li) and tert‐butyllithium (t‐Bu‐Li), used for the exfoliation of bulk MoS₂. Scanning transmission electron microscopy (STEM), Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) are adopted for a comprehensive characterization of all materials under investigation. In addition, catalytic properties towards the hydrogen evolution reaction (HER) and capacitive properties are also tested. Different organolithium compounds exhibit different extent of Li intercalation resulting in different degrees of exfoliation. The inherent electrochemical behavior of MoS₂ consisting of significant anodic and cathodic peaks as well as its capacitive behavior and catalytic properties towards hydrogen evolution reaction are strongly connected to the exfoliation compound used. This research significantly contributes to the development of large‐scale synthesis of electrocatalytic MoS₂‐based materials.