用共振电离飞行时间质谱仪分析土壤中超痕量气态金

采用激光共振电离飞行时间质谱技术（简称ＲＩＳ－ＴＯＦ技术）对土壤中超痕量气态金的含量进行了分析研究。ＲＩＳ－ＴＯＦ谱仪具有极高的灵敏度和很强的选择性，避免了对样品的预富集过程。本文给出了该谱仪对金元素的检测限和６５个土壤中气态金样品的分析结果，以及用中子活化法随机抽样检查的结果。     

Determination of Biodegradation Process of Benzene, Toluene, Ethylbenzene and Xylenes in Seabed Sediment by Purge and Trap Gas Chromatography

Benzene, toluene, ethylbenzene, and xylenes (BTEX) are commonly found in crude oil and are used in geochemical investigations as direct indicators of the presence of oil and gas. BTEX are easily volatile and can be degraded by microorganisms, which affect their precise measurement seriously. A method for determining the biodegradation process of BTEX in seabed sediment using dynamic headspace (purge and trap) gas chromatography with a photoionization detector (PID) was developed, which had a detection limit of 7.3–13.2 ng L^?1 and a recovery rate of 91.6–95.0%. The decrease in the concentration of BTEX components was monitored in seabed sediment samples, which was caused by microorganism biodegradation. The results of BTEX biodegradation process were of great significance in the collection, transportation, preservation, and measurement of seabed sediment samples in the geochemical investigations of oil and gas.     

激光单分子探测技术的研究

文中介绍利用激光激发分子荧光的方法探测液体中单个染料分子的新技术，以及作者自行设计和研制的激光单分子探测谱仪。通过探测“光子爆发”，把单个染料分子的荧光同很强的背景杂散光区别开来。进一步用８２ＭＨｚ高重复频率的锁模激光器和时间门符合技术，成功地消除了Ｒａｍａｎ散射光。目前该谱仪达到的检测限为灵敏区内仅有～７个Ｒ６Ｇ分子。     

换个角度看近地人造卫星的运动

将卫星的近地轨道运动等效为无阻力条件下物体沿地球内两相互垂直的直径轨道的简谐振动的合运动,从而解释了它们的运动周期相同这一事实.     

Voltammetric determination of malachite green in fish samples based on the enhancement effect of anionic surfactant

In this work, an electrochemical method for the determination of malachite green was developed on the basis of enhancement effect of an anionic surfactant: sodium dodecyl benzene sulfonate. It is found that the oxidation peak current of malachite green at carbon paste electrode significantly increases in the presence of low concentration of sodium dodecyl benzene sulfonate in pH 6.5 phosphate buffer, suggesting that sodium dodecyl benzene sulfonate shows obvious enhancement effect for the determination of malachite green. The experimental parameters, such as supporting electrolyte, kind of surfactant, concentration of sodium dodecyl benzene sulfonate and accumulation time, were optimized, and then a sensitive and convenient electrochemical method was proposed for the determination of malachite green. The oxidation peak current is proportional to the concentration of malachite green over the range from 8.0 × 10⁻⁹ to 5.0 × 10⁻⁷ mol l⁻¹, and the detection limit is 4.0 × 10⁻⁹ mol l⁻¹ after 5 min of accumulation. Finally, this new method was successfully employed to detect malachite green in fish samples. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 8, pp. 1019–1024. The text was submitted by the authors in English.     

Rb and Rc in an Extended Standard Model

By the study for the mixing of a charm quark c and a new quark m with the mixing angle θ in an extended standard model, we obtain the theoretical values of R_b and R_c which are fairly accordant with the experimental values of R_b^{ex and R_cex.}     

用胶束电动毛细管色谱法测定海洋沉积物中苯系物

海洋沉积物中苯系物的分析和测量对海洋石油化探具有重要意义。作者用胶束电动毛细管色谱法对海洋沉积物中苯系物进行了测定。考察了十二烷基硫酸钠 (SDS)的浓度和有机添加剂对分离的影响以及影响峰面积重现性和迁移时间的因素。苯系物的浓度和对应的峰面积成良好的线性关系。将该法用来分析石油勘探远景区域海洋沉积物中的苯系物 ,得到了它们的含量范围。     

光子晶体波导定向耦合器

在完整二维光子晶体中引入线缺陷后，就形成了光子晶体波导；将时域有限差分方法(FDTD)用于光子晶体波导耦合研究，计算了不同耦合长度情形下的波导各个出口处的透过率，结果表明：光子晶体波导耦合遵循普通介质波导耦合的一般规律，也有定向耦合的功能。进一步的研究表明：对于不同的频率，光子晶体定向耦合器耦合系数是不同的，并且耦合系数和对应的频率之间近似直线关系。     

毛细管电泳-激光诱导荧光测定大鼠血浆内痕量氨基酸类神经递质

用菁色素衍生物 (Cy5 )作为荧光衍生试剂 ,毛细管电泳结合激光诱导荧光分离测定痕量氨基酸类神经递质甘氨酸和谷氨酸。讨论了Cy5浓度 ,缓冲液浓度 ,pH值和反应时间等实验条件对衍生和分离的影响。衍生物的荧光强度和氨基酸的浓度在 7.5× 1 0 - 8～ 3 .5× 1 0 - 6 mol L范围内呈现良好的线性 ,线性相关系数均达到 0 .999。甘氨酸和谷氨酸的最低检出限浓度分别为 3 .3× 1 0 - 9mol L和 1 .0×1 0 - 9mol L。测定了大鼠血浆中甘氨酸和谷氨酸的浓度 ,分别为 (62± 1 4 )× 1 0 - 6 mol L和 (1 9± 2 )× 1 0 - 6 mol L。与其它氨基标记荧光试剂 ,如FITC和TRITC相比 ,Cy5与一级胺反应时间短 ,选择性高     

吹扫捕集-气相色谱分析海水和沉积物中的苯、甲苯、乙苯及二甲苯

单环芳烃苯、甲苯、乙苯和二甲苯（简称BTEX）是石油的重要组分，也是环境中需要重点监测的致癌污染物。本实验建立了动态顶空（吹扫捕集）和光离子化检测器的气相色谱测量海水、沉积物中痕量BTEX的方法。在120—1200ng／L的浓度范围，苯、甲苯、乙苯、间对二甲苯及邻二甲苯标准溶液的检出限分别为6．4、35．2、15．8、12．3、10．7ng／L，相对标准偏差0．9％-6．1％。样品无需预处理，海水中BTEX回收率为93．50％-98．40％。7个渤海表层海水样品中BTEX的浓度均低于140ng／L；海底沉积物中苯、甲苯、乙苯、间对二甲苯及邻二甲苯浓度分别为169—1243、531—1732、1308—5624、237—1136、510—5194ng／L。测量方法和结果对评价环境污染具有重要意义。