醋酸乙烯—丙烯酰胺共聚物的裂解气相色谱分析

本文采用居里点裂解器—填充柱/程序升温气相色谱系统,对醋酸乙烯—丙烯酰胺共聚物裂解产物进行分离与鉴定。选用国产仪器、最佳裂解时间、最佳裂解温度和最佳裂解样品量;配以最佳PY—GL分析条件,得到了较理想的PY—Gc分离谱图。由指纹特性区谱峰行为与标准物PY—Gc谱图相对照,依高聚物键能裂断理论分析为基点,证实并推论出该样品裂解碎片产生的规律鉴定了裂解产物的主组分,从而认定了醋酸乙烯—丙烯酰胺共聚物的结构及其特性。     

Taxonomic separation by isozyme electrophoresis of two closely related species of Cicada L. (Hemiptera: Cicadoidea) in Portugal

Cicada orni (Linnaeus, 1758) and Cicada barbara (Stal, 1866), two closely related species of cicadas both present in Portugal, are very similar and often impossible to separate on the grounds of the morphology alone. Acoustic signals produced by males during pair formation and courtship are, however, different, which is evidence for the presence of two independent species. With a view to testing the usefulness of isozyme electrophoresis for distinguishing between this pair of species, specimens of both were collected in several locations either in sympatry or in allopatry, and then assayed for 19 enzyme loci. Starch gel electrophoresis gave evidence of genetic differentiation between the groups and strong support that they constitute two independent biological species. Moreover, three loci proved to be diagnostic for the separation between C. orni and C. barbara: aspartate aminotransferase (AAT-1), creatine kinase (CK-1) and malate dehydrogenase (MDH-1).     

Why was M. S. Tswett’s chromatographic adsorption analysis rejected?

The present paper claims that M. S. Tswett’s chromatographic adsorption analysis, which today is a ubiquitous and instrumentally sophisticated chemical technique, was either ignored or outright rejected by chemists and botanists in the first three decades of the twentieth century because it did not make sense in terms of accepted chemical theory or practice. Evidence for this claim is culled from consideration of the botanical and chemical context of Tswett’s technique as well as an analysis of the protracted debate over Tswett’s chromatographic analysis of chlorophyll between him and Leon Marchlewski, a noted chlorophyll chemist of the period. In this way, the paper expands and amends what it calls the ‘textbook story’ of the early history of chromatography, examples of which may be found in historical notes in many textbooks of chemical instrumental analysis and numerous short articles in chemistry journals. The paper also provides an accessible introduction to the early history of chromatography for historians of science likely to know little or nothing about it.     

DNA计算在二次分配问题中的应用研究

DNA计算（DNA computing）是一种新的计算方法,其高度并行性和巨大的信息存储能力为NP-完全问题的解决提供了一种全新的方法。本文采用了该算法去解决二次分配问题,构造了该问题的表达方法,建立了算法模型,对于我们将DNA计算的方法应用于组合优化问题具有启发性,并为我们进一步深入研究奠定了基础。     

分子生态学方法对油藏细菌群落结构分析的比较

目前对油藏细菌群落结构分析方法繁多,为得到准确全面的群落分析结果,必须选取合适的方法。群落分析方法的优劣进行比较分析,选取从新疆陆梁油田注水井筛出的11株单菌,测定其16srDNA序列,制成包含7个菌属、9个菌种的混合菌液。应用基于PCR扩增的三种分子生态技术DGGE、T-RFLP、建立16SrDNA文库比较和分析了混合菌液细菌多样性。使用PCR-DGGE方法时发现,DGGE方法可灵敏地检测到序列1 bp的变化,能将不同菌株分开,但该方法经过切胶测序后的的目标序列较短,信息量不大且有时有一定误差,较适合用于定性对比;而用于菌群结构的分析时应结合其他方法。T-RFLP法可区分大部分菌属,但数据库不够完整,不能确定细菌群落组成;因此也不适合单独用在细菌群落检测中,可用作多个样品种群多样性的对比或结合其他方法对样品进行系统透彻解析。建立16srDNA克隆文库法成功鉴定到7个菌属8个菌种16SrDNA序列,更适用于油藏细菌群落结构的分析。     

百日咳杆菌LPF和FHA的纯化及其特性的研究

采用羟基磷灰石、HP—Sepharose 4B和Sephadex G—200色层分析方法,精制出了单一的白细胞增多促进因子(LPF)和丝状血凝素(FHA)组分.经SDS—PAGE证明,精制LPF呈现四条带,其分子量分别为30,000、27,000、23,000和14,000;精制FHA呈现三条带,其分子量分别为185,000、130,000、105,000.ELISA检测证明,精制LPF为620EU/mL,精制FHA为402EU/mL;小鼠LP和HS活性测定结果证明,0.136μg的精制LPF可引起白细胞的明显增高,0.015μg可引起HS活性,0.29μg可引起组胺致敏小鼠50%的死亡;CHO细胞簇聚活性检测结果显示,3.3pg的精制LPF可引起CHO细胞明显的簇聚反应;免疫双扩散试验结果显示,精制LPF和FHA分别与其相应的抗LPF和抗FHA血清形成特异性的沉淀线;电镜结果显示,精制LPF呈直径约6nm的球形颗粒;精制FHA呈2×40—100nm的丝状结构.     

离子色谱法测定葡萄酒柠檬酸含量

使用离子色谱法利用对葡萄酒中柠檬酸含量进行了分析,利用梯度洗脱实现分离,并且方法的线性好,精密度高、回收率满意.     

高效液相色谱法测定苯并三嗪-1,4-二氧化物衍生物SR-H22及其有关物质

建立了测定苯并三嗪-1,4-二氧化物衍生物SR-H22的含量及有关物质的高效液相色谱方法。采用Dikma Diamonsil C_(18)(250 mm×4.6 mm,5.0μm)色谱柱;流动相A为乙腈,流动相B为水;流速:1.0 m L·min~(-1);等度洗脱,A-B(25∶75,V/V),检测波长为243 nm;进样体积:10μL。在上述色谱条件下,各杂质及各降解产物均可与SR-H22主峰良好分离,HPLC测定的线性范围为0.1~1.5μg(r=0.999 8),方法中仪器精密度、日内精密度、日间精密度及重复性的RSD均小于2%。采用HPLC测定SR-H22含量及有关物质,方法简便,结果准确可靠。     

基于HPLC的葡萄籽提取物指纹图谱的建立

葡萄籽提取物是一种高效的抗氧化剂,其抗氧化效果远高于绿茶等。利用反相HPLC建立葡萄籽提取物的中药指纹图谱,以便于对其质量的优劣进行监测。实验分析了12个不同产地的葡萄籽提取物样品,采用了国家食品药品监督管理局推荐的"中药色谱指纹图谱相似度软件评价系统(2004 A版)"计算处理。建立了25个指纹峰、6个共有峰,确定了3个主要的指纹峰。通过夹角余弦法计算了12个产地的葡萄籽提取物的相似度。建立的指纹图谱可以用来评价不同产地葡萄籽提取物的优劣;并依此为标准,为进一步控制葡萄籽提取物的质量提供依据。