金属载体催化剂的涂层研究

在高温氧化处理不同时间的金属载体箔片上涂覆MgAl2O4/Al2O3过渡涂层,利用TG-DSC,XRD,SEM,BET和超声振动等分析测试技术,对载体和涂层的微观结构与表面特性进行研究.结果表明,在950 ℃下高温氧化5 h,箔片表面生成板状Al2O3晶须,有利于增强涂层与箔片的附着力.在载体表面涂覆一层MgAl2O4/Al2O3过渡涂层,有助于提高活性组分与金属载体的结合力,可以获得高结合强度的涂层结构,促使活性元素高度分散.     

Low latitude ionospheric effects near longitude 120°E during the great geomagnetic storm of July 2000

A great geomagnetic storm occurred on July 15/16, 2000 with a minimum value of about -300 nT in Dst index. Collecting digisonde data from ionospheric stations at Chungli, Wuhan, Kokubunji and Anyang, the ionospheric responses at the low latitudes near longitude 120(E during this storm are analyzed in this paper. There was a strong negative phase storm at low latitudes on July 16. The G-condition in the ionograms was clearly seen on the early first day after the commencement of geomagnetic storm. Those were considered to be caused by the storm-induced increase in the concentration ratios of neutral molecular O2 or N2 to atom O. On July 17 and some days thereafter, a positive phase storm appeared. In addition, anomalous equatorial ionization anomaly (EIA) inhibitions and developments were observed on July 16 and 17. There were also prominent nighttime enhancements in foF2 during these days, and the diurnal variation of foF2 was less clear than before.     

中低纬电离层电场理论模式

介绍了一个电离层电场理论模式. 该模式从电离层发电机理论的基本方程出发, 采用地磁偶极坐标系, 推导出电离层电势满足的微分方程作为电场理论模式的出发方程. 模式的主要输入参量为电离层背景中性风(由经验模式HWM93给出)和电导率(由经验模式IRI90, MSISE90分别给出的电子和离子的浓度、温度以及中性大气的浓度、温度计算得出). 采用松弛迭代法求解电势的偏微分方程得出电势, 进而获得中低纬电离层电场、电流随时间、高度和地磁纬度的分布. 模式很好地再现了电离层电势、电场和赤道电急流的基本结构和形态, 可应用于对高层大气和电离层的电动力学过程的研究.     

基于三阶段DEA的高校教育投入产出效率评价

采用三阶段DEA模型,选取辽宁省36所地方高校为研究对象,以2014年的统计数据为基础,对教育投入产出效率值进行测算.研究表明,剥离环境因素和随机干扰的影响后,教育投入产出效率由0.628下降到0.536,规模效率由0.802下降到0.637,而纯技术效率由0.779提升到0.833,其中33所高校的规模效率下降,31所高校的纯技术效率上升.从调整的数据可以看出,制约综合技术效率提升的主要因素已由调整前的纯技术效率变为调整后的规模效率.最后针对教育投入产出效率值分析,提出提升高校教育投入产出效率的对策.     

The sudden increase in ionospheric total electron content caused by the very intense solar flare on July 14, 2000

The present paper studies the sudden increase in total electron content (SITEC) on the ionosphere caused by the very intense solar flare on July 14, 2000. According to the well-known Chapman theory of ionization, we derive the relationship between the temporal variation rate, of the total electron content (TEC) and the flare parameters. It is shown that is proportional to the effective flare radiation flux, If, and inversely proportional to the Chapman function, ch(χ), of the zenith angle χ. TEC data observed by the GPS networks located in China, Southeast Asia and Australia during the very intense solar flare on July 14, 2000 are used to statistically investigate the relation between the observed and ch(χ). The analyses show that the two quantities are inversely proportional to each other, as the theory predicted. The present work shows that GPS observation is a powerful tool for studying solar flare effects on the ionosphere, I.e. The sudden ionospheric disturbances (SIDs). Because of its advantages of high precision, large geographical distribution and good temporal resolution, GPS TEC observation may reveal quantitatively the process of ionospheric disturbances caused by solar flares. Therefore, our results are of significance in the space weather research.     

巧用泡沫塑料球自制晶体模型

晶体结构具有重要的教学价值和功能,由于内容较抽象,学生学习起来较为吃力。采用价格低廉的泡沫塑料球与毛绒条扭扭棒为材料,由学生自制晶体模型,安全方便、简单易行,能够有效加深学生对晶体结构的理解,提升学生的学习兴趣。另外,利用泡沫塑料球与毛绒条扭扭棒还可制作许多其他化学教学常用模型,可用度高、推广性强。     

A theoretical model for ionospheric electric fields at mid- and low-latitudes

A theoretical model for ionospheric electric fields at mid- and Iow-latitudes is developed.In the geomagnetic dipolar coordinate system, we deduce a partial differential equation of electricpotential from the ionospheric dynamo theory. The deduced equation is taken as the fundamentalequation for the present model. The principal parameters for the model input, the thermosphericneutral winds, the densities and temperatures of electrons, ions and neutral atoms and molecules,are obtained from the empirical models HWM93, IRI90 and MSISE90, respectively. In terms of therelaxation iteration method, the partial equations for electric potential are solved successfully, andthen, the ionospheric electric potential, fields, and currents are derived. Our model can reproducethe main features of the ionospheric electrodynamical processes such as the equatorial electric jet(EEJ), so it will be a useful tool for studying the upper atmosphere and ionosphere.