毛细管电泳-安培检测法测定女贞子中齐墩果酸的含量

女贞子又名冬青子,性凉,味甘、微苦,归肝、肾经,具有滋补肝肾、明目乌发的功能.女贞子主要有效成份为齐墩果酸Oleanolic Acid(OA)[1],其化学结构式如图1所示.OA是天然产物化学成分,毒性很低,具有多种生物活性如抗病毒、消炎、增强免疫和抑制免疫、抑制血小板凝集、降血脂、降糖、保肝、护肾、抗艾滋病毒等[2],故测定其含量可为药品的含量控制提供科学依据.     

高效毛细管电泳安培法测定肉苁蓉中松果菊苷的含量

采用毛细管电泳安培法建立了肉苁蓉中松果菊苷含量的检测方法,探讨了缓冲溶液种类、工作电位、分离电压、进样时间等对分离和检测的影响.在15 mmol/L硼砂缓冲溶液(pH 9.5),25 kV电压,0.6 V工作电位的条件下,松果菊苷的质量浓度在0.5～50.0 mg/L范围内与峰面积呈良好线性,相关系数为0.9994,检...     

高效液相色谱法同时测定食品中的5种添加剂

采用高效液相色谱法测定了食品中山梨酸、苯甲酸、糖精钠、乙酰磺胺酸钾和脱氢乙酸等5种食品添加剂.结果表明:高效液相色谱法能够满足食品中5种食品添加剂同时测定的要求;在0～200 mg/L的线性范围内.相关系数r大于0.999 2,对5种食品添加剂的最低检出限分别为0.15、0.25、0.45、0.17、0.23 mg/k...     

A Time-Dependent Approach to High-Resolution Photoabsorption Spectrum of Rydberg Atoms in Magnetic Fields

A robust time-dependent approach to the high-resolution photoabsorption spectrum of Rydberg atoms in magnetic fields is presented. Traditionally we have to numerically diagonalize a huge matrix to solve the eigen-problem and then to obtain the spectral information. This matrix operation requires high-speed computers with large memories. Alternatively we present a unitary but very easily parallelized time-evolution method in an inexpensive way, which is very accurate and stable even in long-time scaie evolution. With this method, we perform the spectral caiculation of hydrogen atom in magnetic field, which agrees well with the experimentai observation. It can be extended to study the dynamics of Rydberg atoms in more complicated cases such as in combined electric and magnetic fields.     

Enhanced p-Type ZnO Films through Nitrogen and Argentum Codoping Grown by Ultrasonic Spray Pyrolysis

The N-Ag codoped ZnO films are deposited on quartz glass substrates by ultrasonic spray pyrolysis technology. The results indicate that the p-type conductivity in ZnO films is greatly enhanced by the double acceptor codoping of N and Ag compared with that of Ag- and N-monodoped ZnO films, and the NAg codoped low-resistivity p-type ZnO films with the resistivity of 1.05 Ω·cm, relatively high carrier concentration of 5.43×10^17 cm^-3, and Hall mobility of 10.09 cm^2 V^-1s^-1 are obtained under optimized conditions. This achievement confirms that p- type ZnO with acceptable properties for optoelectronic applications could be realized by simultaneous codoping with two potential acceptors.     

复合材料残余应力的拉曼测定

本文报道在拉曼光谱仪中用拉曼光谱术和荧光光谱术测定复合材料残余应力(应变)的方法和结果。复合材料组分中Al2O3的荧光R1峰、Si晶体和SiC纤维拉曼峰的位置(波数)随应变的偏移与应变值都有近似的线性关系。这种关系可用于确定复合材料中由外负荷力学作用或热学作用引起的残余应变。在显微拉曼系统中测定了ZrO2-Al2O3层状复合材料,Al-Si共晶体和SiC纤维增强玻璃复合材料的残余应变及其空间分布。     

光学天文望远镜的足迹

文章以较为轻松的笔调概述了光学天文望远镜400年的发展史.全文分7个部分,内容包括望远镜的诞生、像差和消色差透镜、传统的反射望远镜和折射望远镜、施密特望远镜的作用、当代巨型望远镜的出现、空间望远镜,以及对月基望远镜的憧憬.     

植物个体远程辐射信号早期传递过程的研究体系创建

自2005年以来,活体中的远程辐射旁效应逐渐成为辐射生物学的研究热点,然而其早期信号传递过程的相关研究却鲜见报道,主要原因是由于早期信号传递过程研究所需的旁区与辐射区的自由分离与组合在动物模型上无法实现。本研究是基于植物个体可以切割和嫁接的特性,借鉴离体细胞培养基转移方法研究旁效应早期过程的思想,在植物个体上实现旁区与辐照区的"分离"与"组合",构建了一种研究个体远程辐射信号早期传递过程的植物实验体系。具体是以模式植物拟南芥菜转基因系(AtRAD54promoter∶∶GUS)为材料,同源重组修复相关基因AtRAD54表达水平为生物学检测终点,人为地将辐照区的组织(或器官)与旁区部分"分离"或"嫁接",通过测定旁区组织(或器官)的AtRAD54基因表达水平变化,研究其辐射信号传递的早期过程。该研究体系的创建为活体旁效应早期过程的研究提供了一种可行的研究方法。     

BESⅢ barrel time-of-flight (TOF) calibration using cosmic ray data

The principle of the method for the BESⅢ TOF calibration using cosmic ray data without magnetic field are reported in this paper. After applying calibration constants, the single-end readout time resolution could reach about 150 ps, and the time resolution for one layer is achieved to be about 110 ps. The paper also described the extraction scheme for the event start time of cosmic events.     

剪切磁场位形下电阻壁模不稳定性的数值模拟

数值研究了平衡磁场位形对电阻壁模稳定性的影响。研究发现,磁场剪切对电阻壁模有解稳作用,对于不同的剪切磁场位形,最不稳定的电阻壁模的环向模数和极向模数不同。等离子流对电阻壁模的增长有抑制作用,稳定住电阻壁模的临界流速度随着磁场剪切率的增大而增大。电阻壁模经线性增长后,进入非线性演化阶段,最后达到饱和状态,剪切磁场位形下的扰动磁能比均匀磁场位形下的扰动磁能饱和度高。