距离调控纳米多孔金表面增强荧光特性

通过调控纳米多孔金(NPG)基底与荧光分子之间的距离,系统研究了其表面增强荧光特性.利用物理气相沉积方法在NPG表面沉积二氧化硅薄膜,通过调整二氧化硅的厚度来控制NPG与荧光分子之间的距离,系统研究了NPG孔径尺寸以及与荧光分子之间距离对其表面增强荧光(SEF)特性的影响.由于多孔金具有纳米级多孔结构,其表面等离子体能够通过分子附近局域电场的增强使分子的激发光场得到增强,从而提高分子的激发强度和效率;当荧光分子与多孔金表面存在一定距离时,通过与光子之间的共振耦合作用,表面等离子体能够增强多孔金周围电磁场,实现荧光增强.通过研究发现,NPG孔径为36nm、表面二氧化硅厚度为20nm时,表面组装的罗丹明6G荧光分子的荧光强度得到最大增强.     

Nervous tissue proteoglycans

The structure, biosynthesis, localization, and possible functional roles of nervous tissue glycosaminoglycans and proteoglycans were last reviewed several years ago^70,74. Since that time, there has been an exponential increase in publications on the neurobiology of proteoglycans. This review will therefore focus on reports which have appeared in the period after 1988, and especially on those concerning the properties of individual characterized nervous tissue proteoglycans. Related areas such as the regulation of glycosaminoglycan biosynthesis and the roles of cell surface proteoglycans in adhesion and growth control are covered in other contributions to this special topic issue.     

味觉及药物的分子识别与分子拓扑结构的关系—试论中药药性理论

此文利用化学信息论概念，对辣椒碱类分子及具有抗癌作用的N^6-(n烷脲基）嘌呤的分子拓扑相似度指数I（P，Q）进行了计算。结果说明辣味强度与抗癌药效的变化与I（P，Q）的定性判据一致。从味觉的分子识别与药物的分子识别的相似规律出发，对祖国医学的药性理论进行了解释。     

Structure and second-order NLO property of the molecules bridged through n-vertex bis-substituted carborane （n=5, 6, 7）

Density functional theory (DFT) B3LYP at 6-31G* level is employed to optimize the structures of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7) and combined with finite field (FF) formalism to calculate the second-order NLO properties. The results indicate that the structures of n-vertex bis-substituted carborane (n=5, 6, 7) are changed due to bridged donor and acceptor moieties. The distances between two C atoms are becoming longer. And the stability and dipole moment are in- fluenced by changing substituted positions of C atoms. The isomers with the substituents connecting with C atoms of lower coordination number have better stability and larger values of polarizability. One-dimensional structure of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7) is in favor of intramolecular charge-transfer. Meanwhile, the isomer with a larger change of dipole moment has larger value of second-order NLO properties during the charge-transfer process.     

关于硝胺分子中的N-NO2键强度的研究

用B3LYP,B3PW91,B3P86,CCSD配合不同大小的基组及CBS-Q方法计算了在分子NH2NO2,CH3NNO2,(CH3)2NNO2和RDX中离解掉二氧化氮的键离解能.通过对键离解能计算结果和实验结果的比较,作者发现由B3LYP,B3P86和CBS-Q不能计算出满意的键离解能,但是,CCSD和B3PW91方法能计算出与实验值吻合较好的键离解能.考虑到由B3PW91计算耗时要比CCSD方法少得多,因此,作者认为由B3PW91,并配合6-31G(d)基组作为计算这些硝胺分子键离解能的方法.     

关于含能材料硝胺撞击感度的研究

作者在利用Gaussian 98DFTB3P86/6-31G**水平研究了36种炸药分子的撞击感度与其分子结构关系并取得较好结果的基础上,又对33种硝胺炸药分子,仍采用人工神经网络方法进一步研究了撞击感度与分子结构特征量的关联关系.结果表明,所实验的硝胺其含特征量△E(原子化能)的输入方案预测结果最理想,即△E与撞击感度的关联度最强,说明△E可作为预测其撞击感度的标志性指标.     

Synthesis and characterization of a three-ring bent-core compound

To investigate the vacuum-deposited films of the banana-shaped mesogens, we prepared a three-ring bent-core （that is, banana-shaped） compound m-bis（4-p-octoxysryrenyl）benzene （m-OSB） and used it as a prototype for studying the related film physics. Herein the synthesis and the structural characterization of m-OSB are reported.^13C and ^1H NMR spectra and ^1R spectrum confirm that m-OSB has a symmetric and all-trans conformation. The results of differential scanning calorimetry, polarizing optical microscopy and X-ray diffractometry indicate that no liquid crystalline phase but two crystalline phases are present in this material： phase Ⅰ （T〈66℃） and phase Ⅱ （66~C〈T〈157℃）; an isotropic state is observed at above 157℃. Combining the X-ray diffraction and the electronic diffraction, we assign the room-temperature crystalline phase I to orthorhombie system and P212121 space group with cell parameters of a = 7.43A°. b=6.34A°, c=72.07A°, and α=β=γ=90°. Molecular modeling reveals that the molecules in the unit cell adopt a layered structure with an antiferro-eleetrie alignment. The structure of phase Ⅱ is very similar to that of phase Ⅰ. Nonlinear optical measurement shows that m-OSB is active for the second harmonic generation （SHG）. Such characterization of the bulk material is necessary for the understanding of the growth and microstructures in the films.     

三价锕系金属结合能的计算

应用ＥＥＴ理论，给出了三价锕系金属结合能计算公式，得出了已经知道晶体结构的三价锕系金属结构能，这将有利于对锕系金属宏观性能的理论解释。     

用聚合物网络控制液晶分子取向

对在液晶材料中掺入２％的、经可见紫外光固化的聚丙烯酸酯单体进行聚合和在垂直于基片方向上施加一个合适的电场，获取沿摩擦方向一致取向的网络织构及用取向的聚合物网络实现控制液晶分子取向的研究做了报道，并阐述了聚合物网络与液晶的相互作用机理；根据液晶光透射率的计算公式，对实验结果进行了定量分析．