Na_(2)O对低碱度保护渣结晶性能的影响

裂纹敏感性钢种所用连铸保护渣普遍通过提高碱度来增强结晶性能,但高碱度会使得铸坯与结晶器之间的润滑变差,增大铸坯表面产生缺陷的风险。设计低碱度保护渣,使其能够具有与高碱度保护渣同样的结晶性能,并同时保持良好的润滑性能,是协调裂纹敏感性钢种连铸过程中保护渣润滑性与控制传热关系的一项有效措施。本文采用SHTT-Ⅱ单丝设备,对不同Na_(2)O含量保护渣进行结晶性能测试,并绘制TTT和CCT曲线;利用Scigress分子动力学软件进行模拟研究,发现随Na_(2)O含量的增加,保护渣结晶温度升高,结晶率提升,孕育时间缩短,临界冷却速率逐渐增大,结晶出现变早,较易结晶。高温条件下熔渣结构体网络聚合度减小,黏度逐渐降低。在实验用Na_(2)O含量范围内,当Na_(2)O含量增加到15%时,在凝固过程中三配位氧个数增加150左右,有化合物生成。表明增加Na_(2)O含量可以控制弯月面区域极冷条件下的传热,实现低温快速结晶。

氧-接触电荷转移(O_2-CCT)复合物的研究进展

氧可与有机分子形成接触电荷转移（ＣＣＴ）复合物。本文阐述了Ｏ２－ＣＣＴ 复合物的形成机制、部位与平衡及其紫外吸收特点，综术了Ｏ２－ＣＣＴ 复合物在有机物氧化、电离势测定、氧传感器、烃类选择氧化及光聚合等领域的研究与应用进展。

Oxygen-contact charge transfer complexes in organic bicomponent systems

The O-2-CCT absorption spectra of bicomponent systems were measured. The influences of various organic compounds as well as the component concentration on the O-2-CCT formation ability were investigated. The results show that if the difference of O-2-CCT formation ability between the two components is rather large, such as the benzene/isopropyl ether system, only the O-2-CCT absorption of benzene appears, which arises from its higher O-2-CCT formation ability. If the difference of O-2-CCT formation ability is small, such as the isopropyl ether/ethanol system and the dioxane/isopropyl ether system, it is rather easy to form a dynamic equilibrium of two O-2-CCT between the two components, then only one absorption peak appears in the whole concentration range as a result of the repeated addition of the two kinds of O-2-CCT absorption. If the difference of O-2-CCT formation ability is in medium compared with the two cases above, such as the dioxane/ethanol system, there are two kinds of O-2-CCT absorption of dioxane and ethanol in the same system in the form of an equilibrium, then two absorption peaks can be detected in the middle concentration range as a result of the repeated addition of the two kinds of O-2-CCT absorption.