Dye Laser for Absorption Trace Analysis of Sodium

The advent of organic dye lasers made possible many experiments in physics, chemistry and biology. Most of these applications are based on the possibility to tune dye laser emission almost at any wavelength between 3400 Å and 12000 Å.This quality combined with high light power made feasible multiphotone absorption, selective absorption and fluorescence experiments. Recently a group of authors published the papers: “Enhancement of absorption spectra by dye laser quenching I and II”^1,2 which start a new field of applications of dye lasers. Namely if a weak absorber is placed inside the broad band laser cavity the absorption is enhanced and this results in the same absorption bands or lines observable in the spectrally resolved laser output. This effect can be used for detection of the traces of elements as a complementary method to the classical absorption spectroscopy but with much higher sensitivity. Same method could be also very useful for detection of transient species with a very short lifetimes.     

Detection of Metal Ions by Quenching of Dye Laser Emission

A novel laser intracavity method for detecting metal ions is described in which a metal analyte is added directly to a dye ligand and the dye laser emission is monitored as a measure of the analyte's concentration. The technique is both sensitive and selective and may have applications as an indirect probe of chemical analysis and of energy transfer.     

染料掺杂液晶激光器的光谱特性研究

首先从理论上计算出了染料(DCM)掺杂液晶激光器的泵浦阈值能量为9.2×10-7 J,从而选定了最适合的泵浦光源,并在此基础上设计了相应的泵浦光路。通过检测输出激光的光强和波长,从光栅周期、外加电场两个方面着手对激光器的输出光谱进行了特性研究,结果表明,通过改变光栅周期就可以实现出射激光波长在100 nm范围内(585～685 nm)的调谐,符合理论计算值。与此同时,通过施加外加电场也可以实现出射波长的调谐,虽然调谐范围较小,但是也实现了输出激光强度的调谐,强度调谐幅度高达90.2%。染料掺杂液晶激光器的波长和光强双向可调谐特性,大大拓展了其在全光网络通信的应用前景。但是,当电场从0 V·μm-1增加到20 V·μm-1时,出射激光的线宽也从0.4 nm增加到了1.5 nm,在激光器的可调谐应用中也应注意线宽的变化。     

番茄红素脂质体的制备工艺

采用逆相蒸发法和薄膜法两种方法制备番茄红素脂质体.筛选出制备高包封率脂质体的工艺为:卵磷脂与胆固醇之比为3:1,温度为35℃,番茄红素与磷脂比例为1:6,旋转速度为200r/min,此条件下番茄红素脂质体的最高包封率可达71.26%.     

Electrochemical Reactions in Dye Lasers

In recent years a considerable success has been achieved in the development of tunable dye-lasers and their applications. The information on this topic is presented in a series of the review articles.^1-3     

光纤过程检测硫酸亚铁缓释片释放度

建立光纤药物溶出度实时测定仪（FODT）在线监测硫酸亚铁溶出度测定的新方法.研究发现通过络合反应检测Fe2＋是可行的,FODT测定硫酸亚铁缓释片释放度与AAS测定结果无统计学意义.利用FODT过程检测硫酸亚铁缓释片释放度,全面直观地反映了药品的释放过程和内在质量,较经典方法能提供更多信息,测定过程简便自动,测定结果准确可靠.     

Dye assisted enhanced transmission in near field optical lithography

Surface plasmon lithography using embedded-amplitude masks has received considerable attention in recent times for its ability to produce high density features with resolution beyond diffraction limit. However plasmon damping caused due to intrinsic metal absorption restricts the achievable aspect ratio of the fabricated features. One possible way to rectify this issue is to use a gain medium to amplify the surface plasmons and thereby increase their propagation length. In this context this paper proposes a novel concept of employing dye medium to enhance plasmon propagation in mask based surface plasmon lithography, so as to obtain higher transmission depth in the writing medium. The proposed concept is supported by numerical simulations and the results obtained indicate a 14.5 fold field enhancement in presence of dye (gain) medium.     

卓酚酮偶氮染料的合成及其光谱性质

选择卓酚酮为偶合组分,与对苯二胺为重氮组分合成偶氮染料,利用核磁共振氢谱、红外光谱、紫外光谱、荧光光谱对合成的偶氮染料进行了结构鉴定及分析,并对紫外光谱数据进行了回归分析。     

超声波条件下降解染料废水的工艺条件研究

采用Fenton试剂对模拟染料废水的降解效果进行研究。结果表明,H2O2投加量、Fe2+投加量、pH值条件、超声处理时间的改变对染料废水的处理效果影响很大。对酸性染料:当pH为4.5,30%H2O2投加的体积分数为30mL/L,Fe2+投加的质量浓度为400mg/L,反应时间为40min时为降解反应的最佳操作条件。对碱性染料,正交试验表明当pH为4、30%H2O2投加的体积分数16mL/L、Fe2+投加的质量浓度为300mg/L、反应时间为60min时为降解反应的最佳操作条件,其降解率达98.46%,COD的去除率达到96.7%。     

Turnable Second Harmonic Generation from an Organic Dye Laser

Abstract

Ultraviolet light has been generated from a Rhodamine 60 organic dye laser by frequency doubling with a KDP crystal. The second harmonic was tuned from 2900Å to 3000Å with peak powers of 40 watts.

Organic dye lasers have now been reported with output wave-lengths extending throughout the visible and near infrared^1-12. The tunability^4,6,13 and output energies now available in the visible protion of the spectrum suggest frequency doubling as a means of obtaining a tunable source of ultraviolet light. We wish to report the observation of tunable second harmonic radiation centered at 2950Å generated from the laser output of a 10^?4 molar solution of Rhodamine 6G dissolved in ethyl alcohol.     

Fluorescent Temporin B Derivative and its Binding to Liposomes

Temporins are short (10–13 amino acids) and linear antimicrobial peptides first isolated from the skin of the European red frog, Rana temporaria, and are effective against Gram-positive bacteria and Candida albicans. Similarly to other antimicrobial peptides, the association of temporins to lipid membranes has been concluded to underlie their antimicrobial effects. Accordingly, a detailed understanding of their interactions with phospholipids is needed. We conjugated a fluorophore (Texas Red) to a Cys containing derivative of temporin B (temB) and investigated its binding to liposomes by fluorescence spectroscopy. Circular dichroic spectra for the Cys-mutant recorded in the absence and in the presence of phospholipids were essentially similar to those for temB. A blue shift in the emission spectra and diminished quenching by ferrocyanide (FCN) of Texas Red labeled temporin B (TRC-temB) were seen in the presence of liposomes. Both of these changes can be attributed to the insertion of the Texas Red into the hydrophobic region of the bilayer. Resonance energy transfer, steady state anisotropy, and fluorescence lifetimes further demonstrate the interaction of TRC-temB with liposomes to be enhanced by negatively charged phospholipids. Instead, cholesterol attenuates the association of TRC-temB with membranes. The interactions between TRC-temB and liposomes of varying negative surface charge are driven by electrostatics as well as hydrophobicity. Similarly to native temporin B also TRC-temB forms amyloid type fibers in the presence of negatively charged liposomes. This property is likely to relate to the cytotoxic activity of this peptide.     

一种新型聚合物激光染料

报道了一种新型聚合物染料的受激发射特性     

Flashlamp Pumped Emulsion Dye Laser

Results of experimental study of flashlamp pumped cc-NPO emulsion dye laser are reported. Superior quality α-NPO emulsion over α-NPO solution in n-hexane is found.     

Laser Excitation Spectroscopy of the Jet-Cooled Methoxy Radical Amidst Hydroxyl Transitions

Abstract

Laser-induced fluorescence excitation spectra of the methoxy radical have been recorded under high resolution in a supersonic jet expansion. The rotational structure associated with the 3¹ ₀ band of methoxy has been identified in the midst of strong overlapping rotational transitions due to the hydroxyl radical in the 32240 - 32580 cm^?1 spectral region. Rotationally-resolved à ²A₁ – [Xtilde] ²E spectra of the 3¹ ₀ band of methoxy have been explicitly assigned using the nomenclature for prolate symmetric top transitions in doublet states.     

3ω/2谐波光谱与发射角度的关系

测量了 1 .0 53μm激光和金盘靶相互作用产生的 3ω/ 2谐波红移峰的波长移动量与谐波发射角度之间的关系 ,并根据有关物理模型推断出电子温度 ,排除了 3ω/ 2谐波与 TPD不稳定性发生在同一区域的可能性。     

Neutron Production from Structured Targets Irradiated By an Ultrashort Laser Pulse

Journal of Russian Laser Research - We study the laser-driven generation of thermonuclear neutrons from targets with a microstructured surface in the form of deuterated microwires, using...     

Examining Protein-Lipid Interactions in Model Systems with a New Squarylium Fluorescent Dye

The applicability of newly synthesized squarylium dye Sq to probing the changes in physical characteristics of lipid bilayer on the formation of protein-lipid complexes has been evaluated. Lipid vesicles composed of zwitterionic phospholipid phosphatidylcholine (PC) and its mixtures with positively charged detergent cetyltrimethylammonium bromide (CTAB), anionic phospholipid cardiolipin (CL), and cholesterol (Chol) were employed as lipid component of model membrane systems while protein constituent was represented by lysozyme (Lz). Fluorescence intensity of Sq was found to decrease on Lz association with lipid bilayer. This effect was observed in all kinds of model systems suggesting that Sq is sensitive to modification of lipid bilayer physical properties on hydrophobic protein-lipid interactions. It was found that Sq spectral response to variations in Chol content depends on relative contributions of electrostatic and hydrophobic components of Lz-membrane binding.     

用氮分子激光器泵浦的绿光区染料激光

用氮分子激光器作泵浦源,对新合成的六种吡喃鎓盐染料的丙酮溶液,获得在501—585nm波段内连续可调激光输出。本文对这些染料的激光特性进行了分析和讨论,并对它们的热化学和光化学稳定性进行了研究。     

凝胶基质高效可调谐固态染料激光器

采用溶胶－凝胶工艺制成激光染料掺杂有机改性凝胶玻璃。用室温下调ＱＮｄ：ＹＡＧ激光器倍频光泵浦凝 胶基,成功地获得了高转换效率,长寿命,可调谐固态染料激光器的激光输出。其中ＳｉＯ２－Ｏｒｍｏｓｉｌ基质Ｐｙｒｒｏｍｅｔｈｅｎｅ５９７染料激光器,激光输出阈值低于１０μＪ,斜率效率η＝６１％,５５０－５９４ｎｍ波长范围内连续可调谐,激光输出能量下降１０％所承受的激光脉冲数大于２．５＊１０＾４个（激光泵浦频     

K-Shell Spectra from CH-Tamped Aluminum Layers Irradiated with Intense Femtosecond Laser Pulses

X-ray spectra of H-like and He-like aluminum ions from aluminum buried in CH layers irradiated with 30fs, 200 TW laser are measured. The electron temperature and density are derived from line ratios of the He-α resonance line to its satellite lines. Typical temperatures of 490-646 eV and electron densities up to 7 × 10^20 cm-3 are obtained. The results show that the electron density increases and temperature decreases with the increasing CH thickness.