溴化十二烷基吡啶和羟胺协同增敏显色反应的研究

系统地研究了钼－羟胺（ＨＹ）－邻苯二酚紫（ＰＶ）－溴化十二烷基吡啶（ＤＰＢ）体系的四元胶束混配物协同增敏显色反应。在ｐＨ４￣５的弱酸性条件下，Ｍｏ－ＰＶ二元配合物生成速率很慢，须加热才能完成，最大吸收波长λｍａｘ＝５１０ｎｍ，表观摩尔吸光系数εｍａｘ＝６．１×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１；Ｍｏ（Ⅵ）－ＰＶ－ＤＰＢ配合物在室温下缓慢形成１：１：１的配合物，最大吸收波长为５９０ｎｍ，表观摩尔吸     

取代硫脲化合物对作物的生长调节作用

取代脲类化合物已广泛用作除草剂、杀虫剂、杀鼠剂。根据结构活性关系,亦对烯丙基、甲基、二芳基取代硫脲衍生物的植物生长调节活性进行了研究。本文合成了3类取代硫脲化合物:R_1NHCSNHR_2,其中:R_1=苯基,α-萘基,叔丁基,R_2=α-苯基乙     

氧化铽团簇的表面修饰及对其荧光特性影响的研究

采用脉冲激光轰击浸于流动相中的氧化铽固体靶，考察了流动相及其流速、脉冲激光输出功率、修饰剂、添加修饰剂顺序等对所获得的氧化铽有机溶胶荧光性能的影响。UV-Vis和荧光光谱的测试表明：以含有修饰剂的无水乙醇作为流动相，可得到良好荧光性能的氧化铽乙醇溶胶，而环己酮与醋酸乙酯均不适合作为该体系的流动相;最佳流速为0.15 mL·s^-1；脉冲激光输出功率大有利于其荧光性能；最佳修饰剂为乙酰丙酮(acac)和2，2′-联吡啶(2，2′-bipy)，且应原位修饰。     

Preparation of Nanoelectrode Ensembles by Assembly of Nano—Silver Colloid on Gold Surface

A novel method for preparing silver nanoelectrode ensembles(SNEEs) and gold nanoelectrode ensembles (GNEEs) has been developed. Silver colloid particles were first absorbed to the gold electrode surface to form a monolayer silver colloid. N-hexadecyl nercaptan was then assembled on the electrode to form a thoil monolayer on which hydrophilic ions cannot be transfered. The SNEEs was prepared by removing thiol from silver colloid surface through applying and AC voltage with increasing frequency at 0.20V(vs.SCE). Finally,GNEEs was obtained by immersing a SNEEs into 6 mol/L HNO3 to remove the silver colloid particles. By comparison with other methods such as template method ect., this method enjoys some advantages of lower resistance, same diameter,easy preparation,controllable size and density.     

维生素B类药物在薄层原位的近红外付立叶变换表面增强拉曼光谱

维生素Ｂ类药物在薄层原位的近红外付立叶变换表面增强拉曼光谱汪瑗，于秉正张煦（首都师范大学分析测试中心北京１０００３７）（北京大学分析测试中心北京）关键词维生素Ｂ_１，维生素Ｂ_２，薄层色谱，表面增强拉曼散射，近红外付立叶变换拉曼光谱将薄层色谱（ＴＬＣ）...     

Analysis of 17β-Estadiol from Sewage in Coastal Marine by Surface Plasmon Resonance Technique

In this study, surface plasmon resonance （SPR） for monitoring 17β-eatradiol （E2） was developed. The small molecule E2 was immobilized on a CM5 sensor chip for an indirect competitive immunoassay to detect E2. The SPR response bahed on the antigen-antibody reaction was measured by injecting the sample solution into the flow system. The limitation of detection was 0.445 μg/L. The developed SPE-SPR system was applied to analyze the seawater samples. Recovery of E2 was 91.6%-93. 1%. Relative standard deviations（RSD） for the E2 assay were between 10.9%-15.1% （n = 3）. The range of determination of E2 samples from the sewage in the coastal marine environ-ment was between ND（lower than detection limit） and ca. 11.78 ng/L.     

A ONE-STEP SURFACE MODIFICATION PROCEDURE TO PEG-GRAFTED NANO-TITANIA

PEG （Polyethylene Glycol）-grafted nano-titania has been obtained in a one-step procedure using hexamethylene diisocyanate as the coupling agent and dibutyltin dilaurate as the catalyst in toluene at 80℃ and characterized qualitatively by FTIR and quantitatively by elemental analysis and thermogravimetric analysis. A comparison of nano-titania with two other commonly used inorganic nanoparticles, nano-silica and nano-alumina, is made, revealing that reactivity order is nano- silica 〉 nano-alumina 〉 nano-titania in view of PEG grafting. Possible mechanism of PEG grafting is also discussed.