基于大环多胺的新型线型聚合物的合成及与DNA相互作用的研究

设计合成了一种新型线形大环聚合多胺（POGEC）,该聚合物可通过1,3-丙二醇二缩水甘油基醚和1,7-二（二乙氧磷酰基）-1,4,7,10-四氮杂环十二烷反应得到．琼脂糖凝胶电泳和电子扫描光谱（SEM）显示POGEC与DNA有很强的结合能力．当生理浓度的氯化钠溶液加入到已经形成的POGEC／DNA复合物中,DNA可被有效释放．通过荧光光谱测量了POGEC与DNA的结合能力及紧缩能力．圆二色光谱表明POGEC的强结合力并未改变DNA的构象．     

紫外超短脉冲激光的单次测量

 利用瞬态光栅衍射法研制了一台单次频率分辨光学开关激光参数测量仪,可以对脉宽范围在10 ps以内的紫外超短脉冲激光进行单次测量。利用该仪器对重复频率为10 Hz的放电泵浦和单次运行的电子束泵浦KrF准分子激光器的输出脉冲分别进行了单次测量,结果表明：对于放电泵浦,当系统工作在零啁啾附近时,脉冲波形和光谱分布较规则,相位分布起伏较小,当系统偏离零啁啾状态时,脉冲波形和光谱分布不再规则,并且相位分布为抛物线结构;对于单次运行的电子束泵浦,脉冲波形具有多峰结构,光谱具有复杂的调制,脉宽约为2 ps,带宽约为1.3 nm,相位分布为抛物线结构。     

Speedup of self-propelled helical swimmers in a long cylindrical pipe

Pipe-like confinements are ubiquitously encountered by microswimmers.Here we systematically study the ratio of the speeds of a force-and torque-free microswimmer swimming in the center of a cylindrical pipe to its speed in an unbounded fluid(speed ratio).Inspired by E.coli,the model swimmer consists of a cylindrical head and a double-helical tail connected to the head by a rotating virtual motor.The numerical simulation shows that depending on swimmer geometry,confinements can enhance or hinder the swimming speed,which is verified by Reynolds number matched experiments.We further developed a reduced model.The model shows that the swimmer with a moderately long,slender head and a moderately long tail experiences the greatest speed enhancement,whereas the theoretical speed ratio has no upper limit.The properties of the virtual motor also affect the speed ratio,namely,the constant-frequency motor generates a greater speed ratio compared to the constant-torque motor.     

国内外代表性有机化学教材知识体系与教学内容比较

对国内外14本具有代表性的有机化学教材进行了对比研究，对教材的主要教学内容、内容编排、信息化建设、教学目标和出版情况等方面进行了对比，分析了我国有机化学教材建设的优势与不足，为未来有机化学教材建设提出了一些建议。