On the copolymerization of acrylates in the modified microemulsion process

Copolymerization of methyl methacrylate, methyl acrylate, butyl methacrylate, and butyl acrylate in turn was performed in the modified microemulsion polymerization process, i.e., continuous addition of monomer to a preemulsified system. It was found that the particle size of the copolymer microlatex did not change distinctly with the monomer composition. The estimation of emulsifier coverage on the microlatex particles indicated that the process switched from a traditional microemulsion to a normal seeded emulsion polymerization very soon after monomer dropping began. Therefore, a longer dropping time is needed to produce a microlatex with narrow dispersed particle size. Besides, in the modified microemulsion polymerization less emulsifier is needed to produce a stable microlatex. This behavior is related to the mechanism of normal seeded emulsion polymerization during monomer dropping.     

直流放电制备CN自由基及其LIF探测

CN自由基是研究化学反应动力学的典型自由基，CN的动力学行为，如CN＋O2的反应已成为研究自由基－自由基反应的模型体系[1]，同时也在许多实际过程如燃烧过程，星际气体的形成过程中起着重要的作用[2，3]．利用含有CN的化合物进行光解、放电、与亚稳态原子分子进行传能反应是目     

The electronic structure of small lithium clusters

Ab initio molecular orbital calculations using the STO-6G and STO6-21G basis sets have been performed for the cluster series Li _n ⁺ , Li _n , and Li _n ^– (wheren=2–7). Thirty-two optimized structures are discussed and reported, many of which (especially for the anionic structures) have not yet been considered. The calculations suggest that for all three species the optimum geometries are planar. Of the two levels of theories that were investigated, STO-6G//STO-6G and STO6-21G//STO-6G, the latter hybrid theory was found to be less reliable. In particular, for the anionic structures these calculations should provide a platform from which more sophisticated, i.e., configuration interaction, geometry optimization can be performed.     

基于离子液体的炭材料制备、改性及应用

离子液体因其熔点低、液态温域宽、蒸气压低、热稳定性高、电导率高、电化学窗口宽、结构可设计及对许多化合物的亲和性等系列性能而引起人们广泛关注。离子液体在炭材料制备、改性领域展示出了良好的前景及巨大的应用潜力,可直接作为碳源,经过高温炭化实现杂原子掺杂制备多孔炭材料;离子液体也可充当反应介质和致孔剂,将生物质转化为多孔炭材料;此外,由于离子液体与炭材料相容性较好,可以用于多孔炭材料改性制备炭复合材料。基于离子液体的炭材料在电催化、超级电容器、吸附分离及生物医学等领域具有潜在的应用价值。本文总结了基于离子液体炭材料的制备、改性及应用最新研究进展,并着重介绍了其在能源和环境相关领域的应用。     

Pt电极表面及附近水行为的现场红外反射吸收光谱电化学初探

本文用现场红外反射吸收光谱电化学方法和循环伏安法研究了Pt电极表面及附近水的行为. 据不同范围内得到的SNIFTIRS 谱中水峰的变化提出了三种可能的解释: (A)电极上水的吸附取向的改变; (B)电极附近水分子的长程有序的变化; (C)电极上水的氧化及还原, Pt-O化合物的形成导致薄层中水量的减少。     

慢性支气管炎急性发作期病人血中微量元素的变化分析

为观察慢性支气管炎急性女作期血液中微量元素的变化，对１０１例慢性支气管炎急性发作期病人和３０例正常人全血中锌、铁、铜及钙进行检测。结果显示：慢性支气管炎急性发作期病人锌、铁、铜和钙４种元素均明显于正常人。提示患者血中微量元素总量减少，可能是慢性支气官炎易反复感染、加剧病变发展的原因之一。认为合理补充缺乏的微量元素，有助于疾病的防治。     

杂原子B—ZSM—35沸石的干法合成,表征及CO＋H2反应性能的研究

首次利用吸附态模板剂在Ｎａ２Ｏ－ＳｉＯ２－Ｂ２Ｏ３－ＤＥＡ干粉体系中合成了杂原子Ｂ－ＳＺＭ－３５沸石，ＸＲＤ，ＳＥＭ，ＩＲ，及ＣＯ加氢反应研究了其物理化学特性。结果表明，Ｂ原子同晶取代Ａｌ原子进入ＺＳＭ－３５沸石骨加。     

富烯碳原子簇的石墨层间闭合形成机理

本文提出了富烯碳原子簇的石墨层间闭合形成机理，由该机理推出的许多结果与实验事实符合很好。我们认为碳原子簇自由基的快速淬灭及其淬灭速度是富烯碳原子簇形成及其丰度的决定因素。由此得出富烯碳原子簇在给定实验条件下产生的必然性，并预言不同大小的富烯碳原子簇可以通过优化实验条件选择性地合成。     

Ce4＋－Ce3＋循环体系引发淀粉与丙烯酰胺接枝共聚合反应动力学研究

The cyclic initiating system of Ce⁴⁺ - Ce³⁺ - Ce⁴⁺, in which the product of reduced ion Ce³⁺ forming from Ce⁴⁺ after initation being oxidized again to the original oxidizing ion Ce⁴⁺ is examined. The characters of process of the graft copolymerisation using the cyclic initiating system is compared with the ones using ceric and persulphate individually. When using the cyclic systerm as initator, it was more effective to graft polymerise acylamide onto starch and a rather high proportion of graft copolymer was made as opposed to using persulphate individually.     

甲基丙烯酸羟烷基酯与丙烯腈或丙烯酰胺共聚合的研究

测定了亲水性甲基丙烯酸羟烷基酯如HEMA、MHPMA分别与AN或AAM,在60℃不同溶剂中自由基聚合反应的竞聚率。AN(M_1)-HEMA(M_2)共单体,在DMSO或DMF溶剂以AIBN或KPS-IPA引发剂条件下共聚,用Kelen-Tüds法计算的竞聚率变化不大,r_1=0.22-0.25、r_2=0.97-1.05,说明在此均相溶液共聚中,所用的溶剂及引发剂对竞聚率的影响较小,这两种单体能很好共聚。但AAM-MHPMA或AAM-HEMA共单体时,r_1与r_2值相差很大,如前者r_1=0.0433、r_2=3.98,后者r_1=0.0535、r_2=1.89,说明不易共聚,共聚物中主要是MHPMA或HEMA组分。