高氯酸锂在有机溶剂中离子溶剂化和离子缔合的红外光谱研究

利用红外光谱技术研究了LiClO4在碳酸丙烯酸,γ－丁内酯和碳酸二乙酯中的离子缔合和离子溶剂化。溶剂分子谱带的变化证明,锂离子与溶剂分子的相互作用主要是通过羰基氧原子进行的,醚氧也可能参与了相互作用,高氯酸锂的v1和v4谱带变化则证明了溶液中离子对的存在,而离子对的种类与溶剂分子的特性有关。     

高浓度NaBF4/DMF溶液中的离子溶剂化和离子缔合

利用振动光谱技术和量子化学方法研究了NaBF4／DMF溶液中的离子缔合和离子溶剂化现象。DMF分子的谱带变化表明,Na^ 与DMF分子的相互作用是通过DMF分子羰基上的氧原子进行的。Na^ 的溶剂化层内含有4个DMF分子,呈近似的四面体结构。而BF4^-谱带的变化表明,溶液中存在着离子缔合,有直接接触离子对生成。直接接触离子对的含量随溶液浓度增加而增大。     

离子对缔合物萃取分光光度法测定阿莫西林

在弱酸性条件下,阿莫西林能与亚甲蓝(MB)反应生成易被1,2-二氯乙烷萃取的离子对缔合物,其最大吸收波长为λ_max=657 nm。据此建立了测定阿莫西林的萃取分光光度法,药物浓度在0.4～6.8 mg·L-1范围内符合比尔定律,在最大吸收波长657 nm处表观摩尔吸光系数ε= 5.0×104 L·mol-1·cm-1,最低检出限为0.01 mg·L-1,回收率为97.5％～101.3％。实验表明该法可成功地用于药物制剂及尿样中阿莫西林含量的测定,结果令人满意。     

四溴荧光素丁基罗丹明B染料离子时的吸光性质研究

本对四溴荧光素、丁基罗丹明Ｂ各自的吸光性质以及它们的形成的离子缔合物的吸光性质进行了研究。测得四溴荧光素与丁基罗丹明Ｂ在ｐＨ７时的缔合比为１：２。其Ｋｓｐ＝２．１６×１０＾－１８。缔合物的萃取率为８３．２％。为进一步研究四溴荧光素、丁基罗丹明Ｂ的萃取光度分析奠定了理论基础。     

染料激光色立方模型定态性质的描述

应用一般形式的统一色噪声近似得到了洒料激光色立方模型光强分布的福克－普朗克方程。导出了光强分布函数，描述了光强涨落的实验和数值模拟结果以及色噪声对光强涨落的影响。     

染料激光色立方模型的第一通过时间分布

本文首先把Ｊｕｎｇ和Ｈａｎｇｇｉ提出的统一色噪声近似推广到多维情形，从而导出了这一近似下单模染料激光色立方模型的朗之万方程和福克－普朗克方程；得到了该模型第一通过时间分布的平均值，协方差和偏斜率的近似解析式并将其和数值模拟进行比较。     

非等强度,等脉冲相关技术测量甲酚紫染料的吸收恢复时间

利用非等强度、等脉冲相关技术测量甲酚紫染料吸收恢复时间。实验结果给出了甲酚紫染料吸收恢复时间为158ps。     

新型杂化絮凝剂PAC-PDMDAAC对染料废水的脱色光谱分析

用新型杂化絮凝剂聚合氯化铝-聚二甲基二烯丙基氯化铵(PAC-PDMDAAC)处理分散紫和活性艳红两种染料废水。杂化絮凝剂投药量为400和450 mg·L-1时,分散紫和活性艳红的脱色率分别达到99%和86.8%,优于聚合氯化铝(PAC)和复配型PAC-PDMDAAC。杂化絮凝剂处理分散紫的最佳pH为7～12,而处理活性艳红的最佳pH为7～9。分别对两种染料及其杂化絮体进行傅里叶红外光谱扫描,结果表明杂化絮凝剂与两种染料分子的某些基团有络合作用,杂化絮体中羟基峰增大且宽化,杂化絮凝剂对染料废水的脱色以吸附电中和为主。对染料原水以及混凝后上清液进行紫外连续扫描,两种上清液的吸光度都大大降低,同时吸收曲线波峰偏移,进一步说明电中和与吸附架桥的协同作用是脱色的主要机理。同时,杂化絮凝剂对分散紫的脱色是通过破坏醚键以及与—NH₂反应,而对活性艳红的脱色则是通过对—SO₃的置换以及对Cl-的取代。为该新型无机-有机高分子杂化絮凝剂混凝脱色效能及脱色机理研究提供新方法,具有实际意义和应用价值。     

双折射调谐器设计的等色图原理

提出双折射调谐器设计的等色图方法，给出原理。分析表明当晶片光轴处在以折射光线为轴线、顶角为４５°的圆锥面上时，双折射调谐器具有最快的波长调谐速率；当光轴位于过折射光线并与入射面成４５°或１３５°的平面内时，调谐器抑制非所需波长的能力最强。由此给出光轴相对晶片表面的两个优化取向，对石英晶片它们分别为１８．７１２°和５９．９２２°。文中还给出了三块晶片组合的调谐器的设计例子，对其调谐特性进行了简要的讨论。     

Elliptically polarized white light photoviscoelastic technique and its application to viscoelastic fracture

The present paper demonstrates the successful application of the photoviscoelastic technique using elliptically polarized white light to the stress field evaluation of the crack growth in a viscoelastic strip. Using the proposed technique, which can determine both isochromatic and isoclinic parameters simultaneously from a single color image, the time-dependent stress state around a slowly propagating crack tip in a viscoelastic strip plate is successfully analyzed. Then, the time-dependent stress intensity factor extended for linearly viscoelastic materials is evaluated from the experimental results using a method based on the least squares. The results show that the proposed critical stress intensity factor for fast crack growth may be considered as a characteristic property of the material under monotonically increasing load.     

The influence of the quarter wave plates in automated photoelasticity

During the last decades, several methods have been proposed to automate photoelastic analyses. Some procedures are based on the circularly polarised light by using quarter wave plates. However, quarter wave plates are typically matched for a specific wavelength, and an error is introduced at different wavelengths. The error of quarter wave plates affects the measurement of isochromatic and isoclinic data. In this paper, the influence of the errors of quarter wave plates in some of the most common automated photoelastic methods is reviewed. The errors in the photoelastic data are given and the procedures to reduce, or eliminate, them are also suggested.     

Cooperative emission study in ytterbium doped NdVO4

The infrared and visible cooperative emissions of ytterbium ions are studied in Yb-doped NdVO₄ single crystals. The absorption of optical phonons allows the emissions at room temperature when a Nd:YAG laser is used. Low temperature emissions are observed due to the Nd³⁺→Yb³⁺ energy transfer following an argon ion laser excitation of the Nd³⁺ ions. Analysis of the cooperative emission at low doping concentration (1%) indicates that it is generated by distant pair forming Yb³⁺ ions while at high doping concentration (≥ 5%) close ions magnetically coupled and superexchange mechanisms prevail in the emitting process.     

Generation of singlet oxygen by indotricarbocyanine dyes in low-polarity media

We present the results of a study of the spectral luminescence properties of three groups of indotricarbocyanine dyes, each of which is formed from compounds with the same cation and different anions. In high-polarity solvents, in the absorption and emission spectra of the dyes we see one type of center; in low-polarity solvents, due to the presence of different ionic forms of the dyes (free ions, contact ion pairs), we observe either one type or two types of centers. By analysis of the luminescence of molecular oxygen in the 1.27 μm spectral region, we determined the efficiency of photosensitization of ¹O₂ formation by dyes in deuterated solvents. We have shown that in low-polarity solvents, the yield for singlet oxygen generation is higher for indotricarbocyanine dyes which are found in the contact ion pair state and which also contain a heavy atom (I) in the anion. We have observed that an increase in the fraction of contact ion pairs in solution as the dye concentration increases or when an additional salt is introduced leads to an increase in the quantum yield for generation of singlet oxygen. In polar deuterated acetonitrile, the counterion has no effect on the efficiency of photosensitization of oxygen by the dyes. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 684–693, September–October, 2008.