A New Method for the Measurement of Complexation Stability Constant and Average Coordination Number of Metallic Element with Polymer

建立了基于化学平衡理论模型以及凝胶过滤色谱(gfC)-电感耦合等离子体质谱(ICPMS)联用技术的高分子聚合物-金属配合物稳定常数、平均配位数测定新方法。以聚乙烯亚胺(PEI)和Cu2+为例,对形成的PEI-Cu配合物稳定常数、平均配位数进行测定,以0.02 MOl·l-1 HAC-nAAC为流动相,凝胶色谱柱分离大分子PEI-Cu配合物以及Cu的小分子配合物、游离态离子,最后用ICPMS测定不同形态金属元素的浓度;利用建立的化学平衡理论模型,计算PEI与金属离子形成配合物的稳定常数、平均配位数,测得25℃,PH4.1~5.3时,PEI-Cu配合物稳定常数为109.6~1010.7,平均配位数为1.0~1.3。建立的在线分离、测定方法具有快速、准确的特点,为高分子聚合物-金属配合物的研究提供新的技术手段。A new method using gel filtration chromatography(GFC) and inductively coupled plasma mass spectrometry(ICPMS) was developed for the measurement of complexation stability constant and average coordination number of the complex of metallic ion with polymer.As an example,the binding of PEI with Cu2+was shown and investigated.The macromolecular PEI-Cu complex and micromolecular species of Cu (Ⅱ) were firstly separated by a low efficiency GFC column with a mobile phase of 0.02 mol·L-1HAc-NaAc buffer,and then directly introduced into ICPMS for elemental analysis.The results of complexation stability constant and average coordination number characterized by putting the concentration of different species of metallic element into the equations of the novel chemical equilibrium model which was developed in this study.The results shown that the complexation stability constants(KPEI-Cu) were between 109.6and 1010.7and the average coordination numbers(n) were in the range of 1.0~1.3 when pH was changed from 4.1 to 5.3 at 25 ℃.This online,rapid and accurate method of GFC-ICPMS is a novel technique for the research of polymer-metallic complex.厦门大学近海海洋环境科学国家重点实验室自主创新项目(MELRI0703)资助项

The influence of discourse hierarchy on the acoustic manifestation of focus in Mandarin Chinese

采用实验语音学的方法,考察了语篇焦点的声学表现是否受到语篇修辞层级的调节。六位普通发音人朗读了32组实验材料,处于不同层级焦点词的时长、音域、高音点和低音点分别被提取出来做统计分析。结果发现,处于高层级的焦点词时长更长,音域更宽;同时,随着声调组合的变化,不同层级焦点词的高音点和低音点呈现不同的特征,具体体现在对于不含上声的焦点词,高层级焦点词的高音点更高,而对于含上声的焦点词,高层级焦点词的低音点更低

Statistical Analysis of the Sentence Focus Distribution in the Narrative Discourse

该文通过20人对30篇汉语记叙文中语句焦点的标定结果，结合文本标注和统计分析，对焦点在词类和语义角色中的分布规律进行了探讨。结果主要发现，记叙文语篇中焦点词大约占实词总数的五分之一。形容词成为焦点的概率远高于其他词类。焦点在语义角色中分布的总体趋势是：客体论元的焦点化倾向最高，其次是外围论元，最低的是主体论元和谓词部分

The roles of pitch and duration in sentence accent of discourse

本研究通过30篇自然叙事语篇,以韵律词为分析单位,对语篇中音高和时长在语句重音中的作用进行探讨,结果主要发现：（1）韵律词音域的相对宽窄对语句重音起着最主要的作用。（2）音高和时长在语句重音中的作用受到小句音域宽度和韵律词等级的交互影响。在正常韵律词中,1级重音由音高和时长共同发挥作用来实现;2级重音主要靠音高起作用。在强化韵律词中,小句音域越窄,时长在语句重音中的作用越重要。（3）音高和时长之间的相关性主要受到韵律词强度的影响,在弱化、正常和强化韵律词中,音高和时长分别表现出普遍的正相关、不相关和负相关