光子晶体光纤拉制中工艺参数的控制

分析了光子晶体光纤拉制中各工艺参数之间的相互影响,建立了工艺参数与最终光纤结构之间的对应关系.在温度和送料速度的协调控制下,通过调节气压参数可有效控制气孔结构.实验拉制出孔径孔距比分别为0.45和0.8的单模以及高占空比光子晶体光纤.在制备非均匀孔径光子晶体光纤时,仅靠调控工艺参数往往难以拉制出理想结构,本文以一种单偏振单模PCF结构为例,对预制棒结构进行了优化设计.计算表明可由此拉制出满足要求的光子晶体光纤. 关键词： 光子晶体光纤 工艺参数 气压控制 气孔结构     

Excitonic Coupling between B and Q Transitions in Porphyrin Aggregates

The properties of meso-tetraphenylporphine （TPP） aggregates formed in acidic aqueous-organic solutions are investigated by UV-vis spectroscopy. According to the absorption spectra, the Q band absorption of the aggregated TPP shows red shift and intensity enhancement, and a model that includes the participation of water molecules in a porphyrin aggregation complex is proposed, then a qualitative explanation based on Gouterman＇s excition coupling theory is presented. Calculations including eigenenergies, eigenstates and the transition dipole strength of the coupled states are carried out.     

无机化学中的一题多解

无机化学计算中采取一题多解可开拓学生的思维,加深对化学基本原理的理解和掌握,有利于巩固和提高所学知识,并加以灵活运用,做到触类旁通。文章以无机化学教学中化学平衡、电极电势2类问题的计算给予说明。     

The effect of anti-hydrogen bond on Fermi resonance: A Raman spectroscopic study of the Fermi doublet ν1—ν12 of liquid pyridine

The effects of anti-hydrogen bond on the ν₁—ν₁₂ Fermi resonance (FR) of pyridine are experimentally investigated by using Raman scattering spectroscopy. Three systems, pyridine/water, pyridine/formamide, pyridine/carbon tetrachloride, provide varying degrees of strength for the diluent-pyridine anti-hydrogen bond complex. Water forms a stronger anti-hydrogen bond with pyridine than with formamide, and in the case of adding non-polar solvent carbon tetrachloride, which is neither a hydrogen bond donor nor an acceptor and incapable of forming hydrogen bond with pyridine, the intermolecular distance of pyridine will increase and the interaction of pyridine molecules will reduce. The dilution studies are performed on the three systems. Comparing with the values of Fermi coupling coefficient W of the ring breathing mode ν ₁ and triangle mode ν ₁₂ of pyridine at different volume concentrations, which are calculated according to the Bertran equations, in three systems, we find that the solution with the strongest anti-hydrogen bond, water, shows the fastest change in the ν₁—ν₁₂ Fermi coupling coefficient W with the volume concentration varying, followed by the formamide and carbon tetrachloride solutions. These results suggest that the stronger anti-hydrogen bond-forming effect will cause a greater reduction in the strength of the ν₁—ν₁₂ FR of pyridine. According to the mechanism of the formation of anti-hydrogen bond in the complexes and the FR theory, a qualitative explanation for the anti-hydrogen bond effect in reducing the strength of the ν₁—ν₁₂ FR of pyridine is given.     

一例基于5-((萘-1-基甲基)氨基)间苯二甲酸配体的Cd（Ⅱ）金属有机骨架的合成、晶体结构及对酸性氨基酸的检测

以5-（（萘-1-基甲基）氨基）间苯二甲酸（H₂L）与Cd²⁺通过溶剂热法合成出二维层状金属有机骨架[Cd （L）（H₂O）]·H₂O （1）。结构分析显示层与层之间通过π-π和C—H…π相互作用形成了三维超分子结构。值得注意的是,1在酸性条件下发光会显著增强,这可用于选择性的检测酸性氨基酸,1对天冬氨酸和谷氨酸的检测限分别为3.88和5.43 μmol·L^-1。     

茂金属聚乙烯薄膜中晶点的组成与结构

茂金属聚乙烯薄膜中晶点的组成与结构;茂金属聚乙烯;晶点;薄膜;组成;结构     

Mn2Ca双金属簇合物组装去Mn光系统II水氧化复合物的研究

报道了Mn₂Ca双金属簇合物与去锰的PSII 颗粒的光组装过程, 发现Mn₂Ca化合物具有明显的恢复去锰PSII的电子传递和放氧活性的能力, 并且表现了比MnCl₂更高的光组装效率. 我们认为该化合物中Ca与Mn原子之间的羧酸酯桥的连接方式可能有利于水氧化复合物(WOC)的光组装及锰簇的稳定.     

溶液浓度对拉曼光谱线宽和频移影响的实验研究

将液芯光纤技术用于傅里叶变换拉曼光谱测量中,提高拉曼光谱强度10²～10⁴倍.应用该技术,在实验上研究了溶液浓度变化对β-carotene,rhodamine在CS²中的CC键π-π^*跃迁拉曼线频移和线宽的影响.实验结果表明,随着浓度降低(1×10^-7～1×10^-12mol/L),拉曼光谱线峰值发生红移,线宽变窄.     

SF2自由基4s和C态的共振增强多光子电离研究

利用六氟化硫和氩气混合样品直流脉冲放电产生SF2自由基,观测得到320—365nm波长范围内SF2自由基的(2+1)共振增强多光子电离(REMPI)光谱.经分析,该REMPI谱对应于SF2自由基的4s(B1B1)Rydberg态和态的共振双光子吸收,获得了二个态的全对称伸缩振动模(ω′1)和OPLA模(ω′2)的振动频率值.初步澄清了态的带源及振动属性,并对态附近SF2自由基的解离行为进行了讨论 关键词：     

石墨炉原子吸收法测定锡的基体改进剂研究

研究了石墨炉原子吸收光谱法测定锡的混合基体改进剂,用转靶X射线衍射分析探讨了金属元素氧化还原性质不同的两类改进剂的稳定机理,两种改进剂能使锡的灰化温度分别提高到1400℃和1350℃,但Mg(NO₃)₂会对锡的测定造成较大的背景吸收,镍加抗坏血酸后可显示更多的优点,既使灰化温度提高500℃,测定灵敏度也提高2倍,同时又降低了背景吸收和基体干扰,用此法测定水系沉积物标样,结果一致.