薄层扫描法测定槐角及槐角丸中的染料木苷和总染料木素

在硅胶G薄层色谱板上,采用双波长薄层扫描法建立了测定槐角、槐角丸中的染料木苷和总染料木素的分析方法。染料木苷和染料木素的薄层展开剂分别为V(三氯甲烷)∶V(甲醇)∶V(冰乙酸)=25∶7∶4和V(三氯甲烷)∶V(甲醇)∶V(冰乙酸)=15∶1∶0.1,染料木苷和染料木素分别在0.5～3.0μg和0.9～5.0μg范围内呈良好线性。该方法为中药槐角和中成药槐角丸的质量控制提供检测方法。     

Sr2RuO4超导转变温度附近c方向磁阻行为研究

测量了Sr2RuO4正常态和超导转变温度附近(T=1.5K,4.0K,6K)c方向的磁阻,通过对正常态磁阻分析获得了Sr2RuO4在温度4K和6K下的平均自由程.通过超导涨落分析获得了Sr2RuO4的超导特性参数ξab(0)和ξc(0).     

Influence of Gamma-Ray Irradiation on Absorption and Fluorescent Spectra of Nd：YAG and Yb：YAG Laser Crystals

We investigate the influence of gamma-ray irradiation on the absorption and fluorescent spectra of Nd^3＋：Y3A15 O12 （Nd： YAG） and Yb^3＋ ： Y3A15 O12 （Yb： YAG） crystals grown by the Czochralski method. Two additional absorption （AA） bands induced by gamma-ray irradiation appear at 255nm and 340nm. The former is contributed due to Fe^3＋ impurity, the latter is due to Fe^2＋ ions and F-type colour centres. The intensity of the excitation and emission spectra as well as the fluorescent lifetime of Nd：YAG crystal decrease after the irradiation of 100 Mrad gamma-ray. In contrast, the same dose irradiation does not impair the fluorescent properties of Yb：YAG crystal. These results indicate that Yb： YA G crystal possesses the advantage over Nd： YA G crystal that has better reliability for applications in harsh radiant environment.     

Interhemispheric Comparison of Dipole Tilt Angle Effects on Latitude of Mid-Altitude Cusp

A statistical study of interhemispheric comparison of dipole tilt angle effect on the latitude of the mid-altitude cusp is preformed by a data set of the Cluster cusp crossings over a 5-year period. The result shows that the dipole tilt angle has a clear control of the cusp latitudinal location. When the dipole tilts sunwards, the cusp is shifted poleward. The northern cusp moves 1° ILAT for every 15.4° increase in the dipole tilt angle, while the southern cusp moves 1° ILAT for every 20.8° increase in the dipole tilt angle. This suggests that an interhemispheric difference appears in the dependence of cusp latitudinal location on the dipole tilt angle.     

Anisotropic Applied Field Dependency of Two Successive Magnetic Transitions in LiCu2O2

The anisotropy of two successive transitions of the spin-ladder compound LiCu2O2 is studied by the specific heat （ C） under magnetic fields with H / / c and H / / ab （written as H^c and H^ab in the following） up to 14 T. The peak of specific heat at 24.5 K in zero field shifts to lower temperature when the field is increased and the magnitude of the peak is suppressed by the field. On the contrary, the peak of 22.5 K shifts to higher temperature, especially at 14 T. Its magnitude increases in the field of H^c, whereas it decreases in the field of H^ab. We calculate the entropy change between 21 K and 63 K. The different influence of the spin ordering by fields of different direction is obtained. Our experimental results suggest a mixed state between the long range incommensurate helimagnetic ground state and the higher-T short-range dimer liquid state. The temperature range of mixed state is shrunk with the increasing field. Possible mechanism is discussed.     

声光效应实验的理论研究和曲线模拟

本文在已有的实验原理的基础上对实验中所涉及的知识作进一步的介绍,对声光效应的过程作进一步的分析,对实验中数据的测量作相应的讨论,并在实验原理的基础上利用mathematica软件作实验数据曲线的理论模拟,从而为声光效应实验提供更完备的理论参考。     

复合氧化物LaxSr1-xFe1-yCoyO3的合成与表征

用甘氨酸-硝酸盐燃烧法制备了陶瓷粉末复合氧化物LaxSr1-xFe1-yCoyO3(x=0.7,0.3;Y=0.30,0.75,0.90),其结构经UV,IR,XRD,SEM和EDS表征.复合氧化物为立方和正交晶系,粒径15.3 nm-29.8 nm.Co2 可使复合氧化物中原子间作用力发生变化.循环伏安曲线分析结果表明,用复合氧化物制备的电极具有双功能氧化电极的电化学特征.     

微波消解–电感耦合等离子体质谱法快速测定地球化学样品中的碘

建立微波消解–电感耦合等离子体质谱法快速测定地球化学样品中的碘。样品采用10%氨水微波消解,用电感耦合等离子体质谱法进行测定,跳峰扫描,发射及射频功率分别为1 200 W、1 250 W,单元素积分时间为1.5 s,雾化气流量为1.02 L/min。碘的质量浓度在0.00～300 μg/L范围内与质谱峰强度线性关系良好,线性相关系数为0.999 8,检出限为0.012 μg/g。采用所建方法对标准物质GBW 07405、GBW 07407、GBW 07451、GBW 07389、GBW 07309、GBW 07311进行测定,相对误差为0.31%～1.96%,测定结果的相对标准偏差为1.53%～5.41%(n=12)。该方法样品处理过程简便、高效,适用于批量地球化学样品中碘的测定。     

一个NTU博弈的模糊延拓方法

对NTU合作博弈给出了一种模糊延拓方法,得到了模糊延拓后的模糊核心,并举例进行了说明。     

无线电引信的超宽谱辐照效应及其防护

 探讨了超宽谱高功率微波对无线电引信的辐照效应、耦合机理和防护方法。利用超宽谱高功率微波辐照源对多姿态的无线电引信进行了辐照实验并对结果进行了分析,实验表明当引信和弹体的轴向与超宽谱高功率微波的电场极化方向一致时,引信最容易被引爆,辐照效应最明显。通过理论分析和辐照实验找出超宽谱高功率微波能量耦合机理为：引信和弹体上感应的瞬变电压通过引信电源电路传递到执行电路,瞬变电压上升率超过了电路中晶闸管的断态电压临界上升率,使晶闸管意外导通,导致引信误动作。在不影响引信工作特性前提下,采取增加防护器件和替换敏感器件的加固方法,可以提高引信抗干扰能力。采用综合防护加固方法可使引信在超宽谱高功率微波辐照下不再产生误动作,达到了防护加固的目的。