人工神经网络法预测有机物临界体积研究

人工神经网络法预测有机物临界体积研究张向东（辽宁大学化学系沈阳１１００３６）赵立群，张国义（沈阳化工学院高分子化工系１１００２１）１基本原理￣［１］最近几年国内外学者将人工神经网络方法应用于解决化学问题收到较好效果￣［２］。误差反向传播（ＢＰ）模型是...     

季戊四醇酯难燃绝缘油的研究

季戊四醇酯难燃绝缘油的研究陈尔凡，肖毅，徐新（沈阳化工学院高分子化工系沈阳１１００２１）关键词　难燃绝缘油，季戊四醇酯，Ｃ_（５－９）混合酸，酯化反应普通绝缘油（矿物油）耐热性差（闪点低），且使用寿命短。故国际上大力开展了难燃绝缘油的研制［１～５］，...     

（1—x）PbCl2—xNaCl（x≤0.50）复合氯化物体系离子导电性的研究

（１－ｘ）ＰｂＣｌ２－ｘＮａＣｌ（ｘ≤０．５０）复合氯化物体系离子导电性的研究李宝华郑文君（沈阳农业大学基础部沈阳１１０１６１）关键词氯离子导体固体电解质晶界传导中图分类号Ｏ６４６．９现有氯离子导体中，ＰｂＣｌ２基质材料的导电性最好，且具有易于加工成...     

镍硫活性阴极的催化活性及其机理探讨

镍硫活性阴极的催化活性及其机理探讨孙弘（沈阳教育学院化学系沈阳１１００１５）张蕴珊（东北大学化学系沈阳１１０００６）关键词镍硫活性阴极催化活性中图分类号６４６．５前言研制廉价易得、对析氢催化活性高的电极材料以降低能耗，对氢碱工业具有深远的意义。近年来...     

1-(2,6-二甲苯基)-1-苯乙酰基-4-丁基氨基脲的合成与表征

１－（２，６－二甲苯基）－１－苯乙酰基－４－丁基氨基脲的合成与表征刘长令李宗成张少铭龚葆青（化工部沈阳化工研究院１１００２１）杀菌剂甲霜灵和酰胺分别由瑞士汽巴－嘉基公司及山道士公司于７０年代后期开发的、主要应用于防治藻菌纲病原菌特别是卵菌亚纲病原菌...     

超低碳含量超细Bi系超导体原始粉末的制备

超低碳含量超细Ｂｉ系超导体原始粉末的制备毛传斌＊周廉杜泽华（东北大学材料学工程系沈阳１１０００６）（西北有色金属研究院超导材料研究所宝鸡７２１０１４）１引言粉末套管法制备的银包套（Ｂｉ，Ｐｂ）２Ｓｒ２Ｃａ２Ｃｕ３Ｏｘ（２２２３）超导带材（Ａｇ／Ｂｉ（...     

嘧啶脲类化合物的合成及其除草活性

嘧啶脲类化合物的合成及其除草活性李斌林柄栋刘长令魏晓丽（化工部沈阳化工研究院沈阳１１００２１）关键词嘧啶异氰酸酯嘧啶脲合成除草剂４０年代开发的取代脲除草剂如敌草隆等已得到了广泛应用［１］，但由于用药量较大，已逐渐被磺酰脲类除草剂取代。在这类磺酰脲除草...     

工业用水中铁含量的双光束FIA光度法

工业用水中铁含量的双光束ＦＩＡ光度法赵珍义（辽宁大学化学系沈阳１１００３６）李淑凡（辽宁武警总队医院）流动注射分析（ＦＩＡ）具有取样量少、分析速度快、精密度好等优点而被广泛用于分析测试之中［１，２］。目前，ＦＩＡ光度法均采用单光束而开展的研究工作。尚...     

谈分析化学中沉淀效应对化学平衡的影响

谈分析化学中沉淀效应对化学平衡的影响大学化学张士国李红张向东（滨州师专化学系２５６６０４）（辽宁大学化学系沈阳１１００３６）本文对《大学化学》第１１卷第４期发表的题为“分析化学中引入沉淀效应系数的讨论”一文［１］中所提出的分析化学中沉淀效应对化学平衡...     

高考化学应试前综合练习二

高考化学应试前综合练习二唐云汉,龚行三（北京海淀区教师进修学校１０００８０）（广东广雅中学５１０１６０）Ⅰ卷（５５分）一、选择题（本题共有５个小题,每小题１分,共５分。每小题只有１个选项符合题意）１．有关下列化学发现史的叙述不正确的是（）（Ａ）１９６...     

Study on the interaction of CdTe quantum dots with coumaric acid and caffeic acid based on fluorescence reversible tune

This paper describes the synthesis of CdTe quantum dots (QDs) together capped by glutathione and thioglycolic acid (GSH and TGA) in aqueous solution. The narrow photoluminescence (fwhm ≤ 40 nm) CdTe QDs, whose emission spans most of the visible spectrum from green through red, has a quantum yield (QY) of 68% at room temperature. GSH/TGA-CdTe QDs are characterized by various experimental techniques such as optical absorption, photoluminescence and AFM measurements. Coumaric acid and caffeic acid is able to quench the fluorescence of GSH/TGA-CdTe QDs, and the fluorescence intensity is linearly proportional to the concentration of quenchers. The addition of bovine serum albumin (BSA) restores the fluorescence intensity of GSH/TGA-CdTe QDs-coumaric acid system and GSH/TGA-CdTe QDs-caffeic acid system. The fluorescence recovery was due to the interaction of BSA with coumaric acid and caffeic acid, leading to the freeing of the GSH/TGA-CdTe QDs. The fluorescence quenching mechanism of GSH/TGA-CdTe QDs was discussed. The binding constant and thermodynamics parameters of BSA-coumaric acid and BSA-caffeic acid during the binding process were calculated in the paper.     

单宁酸与牛血红蛋白相互作用的光谱研究

利用荧光光谱技术研究了单宁酸与牛血红蛋白分子的相互作用。实验结果表明:单宁酸分子与BHb发生反应生成基态复合物,导致BHb内源荧光的猝灭,该猝灭属于静态猝灭。测定了不同温度下该反应的表观结合常数、结合位点数及结合热力学参数,热力学参数的变化表明上述作用过程是一个熵增加、自由能降低的自发分子间作用过程,单宁酸与BHb之间以疏水和氢键作用力为主;根据Frster能量转移理论,测得供体与受体间结合距离r和能量转移效率E;并用同步荧光光谱法探讨了单宁酸对BHb构象的影响。     

Fluorescence properties of trans-ethyl-p-(dimethylamino) cinnamate in presence of bile acid host

The knowledge of the formation of bile acid micellar aggregates is of great importance because of the biological significance of these compounds and their pharmacological applications. The intramolecular charge transfer (ICT) fluorescence property of trans-ethyl-p-(dimethylamino) cinnamate is used to study the micelles formed by aggregation of three most important bile acids, viz. cholic acid, deoxycholic acid and chenodeoxycholic acid by steady state and picosecond time-resolved fluorescence spectroscopy. The ICT fluorescence band intensity was found to increase with concomitant blue shift with the addition of bile acids. The blue shift in ICT fluorescence maxima as well as decrease in nonradiative decay constants in presence of bile acids indicate the passage of the probe towards the micro domains formed from the aggregated bile acids. Binding constant of the probe with micelles as well as critical micelle concentration and average polarity parameter of the micellar environments were obtained from the variation of fluorescence intensity on increasing concentration of bile acids in the medium.     

High-performance liquid chromatographic determination of fatty acid binding proteins in rat liver with fluorescence detection.

A highly sensitive, simple and reproducible method for the quantitative determination of fatty acid binding protein in rat liver by post-column high-performance liquid chromatography with fluorescence detection is presented. Fatty acid binding protein in rat liver cytosols is separated by gel-permeation column chromatography, which is followed by fluorescence detection. The detection makes use of the fluorescence enhancement observed when a fluorescent fatty acid probe, dansylundecanoic acid, binds to fatty acid binding protein. The method is rapid, simple to perform and highly sensitive. The method was applied to the determination of fatty acid binding protein in liver from control and hypolipidaemic drug treated rats.     

苯甲酸铽络合物发光性能的研究

本文应用紫外、红外吸收光谱、稳态和时间分辨的荧光光谱研究了苯甲酸及它的(邻、间、对)羟基衍生物与铽离子的络合物的发光性能和能量传递关系;探讨了羧酸的结构、络合物的形成,以及溶剂、pH值对发光强度和能量传递的影响。     

Ratiometric fluorescence response of N-methylacridone for methanesulfonic acid.

A new method for the sensitive and selective determination of stronger acids, such as methanesulfonic acid, based on an acid-base interaction with N-methylacridone fluorophore (1), is proposed. The fluorescence spectrum of 1 was changed drastically by the addition of methanesulfonic acid in methanol. A ratiometric analysis of methanesulfonic acid by measuring the fluorescence intensities of 1 both at 426 nm and 473 nm showed good linearity with a correlation coefficient of 0.9995.     

氢化物发生-原子荧光光谱法(HG-AFS)测定特硬铅合金中硒和碲

建立了氢化物发生-原子荧光光谱法(HG-AFS)测定特硬铅合金中硒和碲的分析方法。试样经硝酸和酒石酸溶解,硫酸沉淀分离基体铅元素。移取部分试液,在40%盐酸介质中直接用氢化物发生-原子荧光光谱法(HG-AFS)测定样品中的硒;另移取部分试液,加入氢溴酸挥发除去砷、锑、锡、硒等元素,在40%盐酸介质中用氢化物发生-原子荧光光谱法(HG-AFS)测定样品中的碲。考察了测定的最佳条件、铅及共存元素对测定的影响。测定硒和碲的相对标准偏差分别为7.5%～9.3%和3.6%～13.0%,加标回收率分别为88%～92%和98%～102%。准确度和精密度均能满足分析需要,具有较强的实用性。     

司帕沙星与卤素反应产物的荧光特性及其应用

研究了卤素（F,Cl,Br,I)与喹诺酮类药物司帕沙星反应产物的荧光特性,发现在酸性介质中,亚硝酸可氧化司帕沙星继而被卤素取代,所得产物具有强烈的荧光发射,其荧光强度随着卤素原子半径的增大呈现规律的增强效应。司帕沙星卤代物荧光较司帕沙星强58－151倍。据此建立了卤素增强荧光光谱测定司帕沙星的新方法。该方法用于直接测定尿液中司帕沙星的含量,结果令人满意。本文还对司帕沙星的荧光增敏机理进行了探讨。     

Fluorescence studies on binding of pyrene and its derivatives to humic acid

Binding of pyrene (PyH) and its derivatives to humic acid (HA) has been studied by fluorescence spectroscopy. The nature of the interaction between HA and pyrene derivatives are extensively investigated by employing three derivatives ranging from anionic to cationic compounds: 1-pyrenebutylic acid (PyA), 1-pyrenemethanol (PyM), and 1-pyrenebutyltrimethylammonium bromide (PyB). Binding constants between HA and PyX (X=H, A, M, B) are obtained by steady-state fluorescence quenching techniques, and it is found that PyB has a markedly large binding constant among the pyrene family. This is attributed to a strong electrostatic interaction between cationic PyB and anionic HA. The result suggests that an electrostatic interaction plays a dominant role in binding of pyrenes to humic acid. The importance of electrostatic interaction was also confirmed by a salt effect on the binding constant. Influence of collisional quenching on the binding constant, which causes overestimation of the binding constant, was examined by time-resolved fluorescence spectroscopy as well as temperature effect in steady-state fluorescence measurements. It is elucidated that collisional quenching does not much bring overestimation into the binding constants.     

GEOMETRIC REQUIREMENTS FOR THE INTRAMOLECULAR QUENCHING OF INDOLE FLUORESCENCE BY AMIDE AND CARBOXYLIC ACID GROUPS IN RIGID MOLECULES WITH THE [2,2,1]BICYCLOHEPTENYL SKELETON

Abstract— The geometric requirements for intramolecular fluorescence quenching of indole by carboxylic acid and amide functions have been determined in rigid norbornyl ([2.2,1]bicycloheptenyl) skeleton: trans and cis 3-(3'-indolyl) norbornene 2-dimethylcarboxamides or carboxylic acids. The reference compound was the 3-(3'-indolyl) N-dimethylpropionamide or -propanoic acid. The quenching occurs mainly in protic solvents. In the cis compounds, the quantum yields are strongly decreased when compared to the trans and open chain compounds. As determined by the pH dependence of fluorescence of the acids, it is in the acid form—COOH that the fluorescence is quenched; in the ionized species -CO⁻₂, only small quenching is observed. The K_s of Stern-Volmer equations are very small for the cis bicyclic acid and amide, the indole nucleus being shielded on one side only. The results support the hypothesis that small rearrangement of the peptide bond in protein conformation changes may be detected by fluorescence.