Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.     

克菌丹和灭菌丹的气相和液相色谱分析方法

采用气相色谱法和高效液相色谱法两种方法分别对克菌丹和灭菌丹进行定性定量分析。气相色谱法均以邻苯二甲酸二戊酯为内标物,色谱柱采用3%OV-101 chromosorb AW DMCS 150~177μm,1 m×3 mm玻璃柱,柱温为195℃,汽化温和检测温均为230℃,克菌丹和灭菌丹的回收率分别为99.2%~100.7%和98.8%~99.9%;方法相对标准偏差分别为0.46%和0.59%。高效液相色谱法中使用Nova-PaK C18250 mm×4.6 mm色谱柱,以V(甲醇)∶V(水)=85∶15为流动相,检测波长为225 nm。克菌丹和灭菌丹的回收率分别为99.5%~100.6%和98.9%~99.7%;方法相对标准偏差分别为0.68%和0.51%。     

一步法合成多羟基酚酸芳基酯

一些多羟基酚酸芳基酯具有显著的生理活性,可用于医药、饮料和食品等方面。但目前关于多羟基酚酸芳基酯的合成还研究得不多。传统的方法是(1)保护多羟基酚酸中的酚羟基,(2)活化羧基成酰氯,(3)酯化,(4)去保护基的四步方法。本文将报道多羟基酚酸——2.4——二羟基苯甲酸(1)直接与酚类成酯的反应。即将二氯磷酸芳基酯(ROPOCI_2)(3)作为缩合剂,应用于一步法合成(1)芳基酯,以较好产率得到了(1)的七个新芳基酯(2_a—2_g),并经元素分析及波谱鉴定。同时还首次研究了缩合剂     

N掺杂可见光化催化剂的研究

The N-doped, yellow colored titanium oxide photocatalysts were prepared with Ti(SO4)2 and NH4HCO3 as precursors by precipitation method. The photocatalytic ability under the irradiation of UV or visible light for the catalysts prepared was studied by degradation of styphnic acid. The materials were characterized by EDS, XRD, FTIR, UV-Vis DRS, and XPS. The results indicate that the photocatalytic ability of catalysts is improved, especially the ability of visible light response. The results of UV-Vis DRS show that the response wavelength range of N-dopped nitrogen is red shifted, the absorption region is expanded to 476 nm.     

银杏叶中脂肪酸的GC-MS分析研究

银杏叶用石油醚提取，经皂化、酯交换法处理，用GC-MS对其脂肪酸化学成分进行了分析和鉴定。经DB-1柱分离出39个峰，鉴定了其中的34种化合物，占总含量的94．37％。其中饱和脂肪酸占31．64％；不饱和脂肪酸占34．23％；烷基酚占14．07％；其它部分占14．43％。     

高效液相色谱法测定伸筋丹中士的宁含量

 采用高效液相色谱法（ＨＰＬＣ）测定了中成药伸筋丹中士的宁含量。色谱条件：氰基柱并加同种类预柱；流动相：甲醇－水－乙酸－三乙胺（９８００：１５５：３０：１５）；ｐＨ６．７；流速：１．０ｍＬ／ｍｉｎ；紫外检测，波长２５４ｎｍ；在４～２０ｍｇ／Ｌ浓度范围内，士的宁的峰面积Ａ与浓度Ｃ间的回归方程为：Ａ＝－７．０１×１０~３＋９．０８×１０~５Ｃ（ｒ＝０．９９９９）；外标法定量，方法精密度ＲＳＤ＝１．９１％（ｎ＝６）。     

Cu2+/Mn2+存在下白花丹素对人血清白蛋白构象的影响

用圆二色和拉曼光谱法表征了Cu²⁺或Mn²⁺存在下白花丹素对人血清白蛋白构象的影响。结果表明,白花丹素改变了人血清白蛋白的二级结构并降低了它的α-螺旋的含量。同时白花丹素也引起了二硫键的构象以及色氨酸和酪氨酸微环境的变化。在Cu²⁺或Mn²⁺存在时这种改变的趋势逐渐增强。     

Synthesis and mesomorphic properties of novel tolane-type liquid crystals

Two series of novel tolane-type liquid crystals(LCs) comprising of hydrogen-bonded organic acids were synthesized.The formation of dimerized H-bond LCs was confirmed by IR spectroscopy,and mesomorphic properties of the LCs were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).It was found that the end groups of the liquid crystals as well as the unsaturated rigid core had effect on the mesomorphic properties.     

SiO2纳米颗粒对R6G-乙醇溶液荧光光谱影响

在3×10-4M和1×10-4M浓度的R6G-乙醇溶液中分别掺杂了8个不同浓度的SiO2纳米颗粒(107～1012个/mL).研究了SiO2纳米颗粒(100 nm)对若丹明6G(R6G)荧光光谱的影响,结果表明:n1～n4(1012～1010个/mL)浓度掺杂的SiO2纳米颗粒在549 nm处的有很好的荧光增强作用,对...