葛根素的荧光光谱研究及应用

在 p H8～ 9的水溶液中 ,葛根素有稳定的荧光 ,最佳激发波长与发射波长分别为 2 58nm和 471 nm。当葛根素浓度为 1 .0× 1 0 - 7～ 1 .0× 1 0 - 6mol/ L时 ,其荧光强度与浓度有良好的线性关系。据此以荧光光度法直接测定了葛根、注射液及葛根提取物中葛根素的含量 ,并以 HPL C法对同一样品进行了对照测定 ,取得满意结果     

PREPARATION OF PARTICLE SIZE NARROWLY DISTRIBUTED LOW-DENSITY STYRENE DIVINYLBENZENE COPOLYMER MICROBEADS

In view of the importance of dispersion agent, the amount of the crosslinking monomer andthe diluent in suspension polymerization for the production of particle size narrowly distributedIow-density styrene divinylbenzene copolymer microbeads (LDPS), their actions are preliminarilyinvestigated in this paper. Experimental results indicate that when both the gelatine and polyvinylalcohol (PVA) are used as dispersion agents, the better effect is achieved. DVB is helpful to theformation of the lower density fine particles, the proportion of the DVB/St should be between1:1～1.5:1. Compared with toluene, gasoline is the more effective diluent for the above target.     

Design,synthesis and biological activity of novel herbicides targeted ALS(Ⅻ)--Quantitative structure-activity relationships of herbicidal l,2,4-triazolo[l,5-a]pyrimidine-2-sulfonanilides

The herbicidal activities of a series of 1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonanilides containing various substituents on the benzene ring were quantitatively analyzed with physicochemi-cal parameters by using Hansch-Fujita method.Variations in the activity were parabolically related to electronic parameters with the optimum pKavalue being about 6.93.The hydrophobic factor in addition to the electronic property seemed to have important effect on the activity.     

不饱和硼烯HClN=B:重排反应的DFT研究

采用量子化学中的密度泛函方法, 在B3LYP/6-311G**水平上研究了不饱和硼烯HClN=B:的重排反应机理。结果表明, 无论是氢原子H迁移还是氯原子Cl迁移都经过1个三元环过渡态,生成直线型产物。但氢原子H迁移是在面内进行, 而氯原子Cl迁移是在面外进行。根据计算结果,详细研究了不饱和硼烯HClN=B:重排反应的热力学及动力学函数, 在此基础上讨论了不饱和硼烯HClN=B:的存在寿命问题。     

聚氨酯分子印章的制备和表征

“软平板印刷”微结构制备技术为微米和亚微米器件的制备提供了一条新的途径 [1] ,已被电子学家和材料学家所应用 ,近年来进入了生物学领域[2 ] .本实验室将这一方法与生物分子电子学相结合 ,提出了用于 DNA芯片在片合成的分子印章法 [3,4 ] .分子印章法的实质是接触压印与组合化学相结合的固相界面反应 .聚二甲氧基硅氧烷 ( PDMS)是一种软印刷的优良材料 [5] ,但是由于其疏水性和较差的机械性能 ,必须对其进行改性才能用来制备 DNA分子印章 [6 ] .　　聚氨酯作为一种功能材料 ,由于分子中交替的软、硬链段及其不同的热动力学性能而形成…     

N,N-二甲基甲酰胺中电沉积制备镁镍储氢合金

采用恒电位沉积法, 选用适宜的添加剂和络合剂, 成功地从N,N-二甲基甲酰胺(DMF)中沉积出致密的黑色Mg-Ni储氢合金膜. 并初步探讨了其共沉积机理. XRD显示沉积层中含有非晶态Mg-Ni相和微晶态Mg相. SEM图及相应能谱图分析表明合金颗粒以团聚状态存在, 合金成分不是很均匀. AAS分析表明沉积合金中Mg的原子摩尔分数达27.3%. LAND电池测试系统测得所镀合金膜的放电比容量最高为172.4 mAh/g.     

Dense Sphene-type Solid Electrolyte Through Rapid Sintering for Solid-state Lithium Metal Battery

The sphene-type solid electrolyte with high ionic conductivity has been designed for solid-state lithium metal battery. However, the practical applications of solid electrolytes are still suffered by the low relative density and long sintering time of tens of hours with large energy consumption. Here, we introduced the spark plasma sintering technology for fabricating the sphene-type Li_1.125Ta_0.875Zr_0.125SiO₅ solid electrolyte. The dense electrolyte pellet with high relative density of ca. 97.4% and ionic conductivity of ca. 1.44×10^-5 S/cm at 30℃ can be obtained by spark plasma sintering process within the extremely short time of only ca. 0.1 h. Also the solid electrolyte provides stable electrochemical window of ca. 6.0 V(vs. Li⁺/Li) and high electrochemical interface stability toward Li metal anode. With the enhanced interfacial contacts between electrodes and electrolyte pellet by the in-situ formed polymer electrolyte, the solid-state lithium metal battery with LiFePO₄ cathode can deliver the initial discharge capacity of ca. 154 mA·h/g at 0.1 C and the reversible capacity of ca. 132 mA·h/g after 70 cycles with high Coulombic efficiency of 99.5% at 55℃. Therefore, this study demonstrates a rapid and energy efficient sintering strategy for fabricating the solid electrolyte with dense structure and high ionic conductivity that can be practically applied in solid-state lithium metal batteries with high energy densities and safeties.     

一种新型的表面声波阻抗传感器及其在液相体系中的应用

一种新型的表面声波阻抗传感器及其在液相体系中的应用姚守拙，陈康，刘德忠，聂利华（湖南大学化学化工系，长沙，４１００８２）关键词表面声波，阻抗传感器，液相应用表面声波传感器（ＳＡＷＳ）具有较高的灵敏度和检测精度，已广泛应用于气体微量组分分析、色谱检测和...     

SYNTHESIS AND EVALUATION OF A NEW PHOTOSTABILIZER—2, 2, 6, 6-TETRAMETHYL-4-PIPERIDINYL SALICYLATE FOR POLYMERS

A new photostabilizer--2,2,6,6-tetramethyl-4-piperidinylsalicylate (TMPS) has been syn-thesized by ester-exchange reaction between 2,2, 6, 6-tetramethyl-4-piperidinol and methylsalicylate.The photostabilizing effect of TMPS and Tinuvin 770, PDS on the photodegradation of cis-1,4-polybutadiene has been investigated for comparison. The results observed show that the mosteffective stabilizer of the three is TMPS. The reason of the good photostabilizing effect of TMPSwas discussed by fluorescence spectra.     

STUDY ON BIODEGRADABILITY OF POLY (3-HYDROXYBUTYRATE-co-3-HYDROXYVALERATE)/ORGANOPHILIC MONTMORILLONITE NANOCOMPOSITES

1. INTRODUCTION Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) has been recognized as apotential environment-friendly substitute for traditional plastics. The structure, mechanicalproperties and biodegradability of PHBV as biodegradable plastic have been reported by many groups [1-3]. However, PHBV presents some problems, such as high cost, slow crystallization rate, relatively difficult processing and high degree of crystallinity. Therefore, it is difficult to use PHBV widel…