A theoretical model for mid-and low-latitude ionospheric electric fields in realistic geomagnetic fields

The geomagnetic fields, which play important roles in the ionospheric dynamo, can greatly affect the global distribution of ionospheric electric fields, currents and other ionospheric electrodynamics phenomena. In the study of ionospheric electrodynamics phenomena, such as the longitudinal variations of ionospheric electric fields, the non-dipolar component of the geomagnetic fields must be taken into account. In this paper, we deduce a theoretical electric field model for ionospheric dynamo at mid- and low-latitude which adopt a modified magnetic apex coordinates system. In the new electric field model, the geomagnetic fields can be calculated from either the IGRF model or the dipole field model, and the neutral winds and conductivities are calculated based on empirical models. Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method, and the ionospheric electric fields and currents are derived from the calculated potential. Our model can reproduce the main features of the ionospheric electrodynamics processes, so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.     

考虑调整成本的Jorgenson投资模型

本文将资本存量的调整成本引入到Jorgenson投资模型，以说明资本存量是如何调整达到最优资本存量的问题。     

一种磨茹香气香料——1-辛烯-3-醇的合成与应用研究

从１－戊醇出发,通过卤代反应,格氏反应,制备得到１－辛烯－３－醇。该产品具有愉快的蘑菇香气,可用于食品香精的调配中。     

Active site of praseodymium orthovanadate catalyst in oxidative dehydrogenation of propane

The pure phase of praseodymium orthovanadate (PrVO₄) has been prepared by the citrate method. The active site of Pr-VO₄ was studied by ESR, NO-TPD, O₂-TPD and¹⁸O₂-isotope exchange methods. The results of ESR and NO-TPD confirmed the presence of V⁴⁺ in the catalyst.¹⁸O₂-isotope exchange was through a single exchange procedure. From the result of O₂ + TPD and the kinetic study of¹⁸O₂-isotope exchange, one can reach a conclusion that the V⁴⁺ species associated with oxygen vacancies are the site for O₂ activation. The adsorbed O₂ or O⁻ are the active oxygen species in propane oxidative dehydrogenation.     

玻璃池窑的计算机辅助设计 I.燃油蓄热室流液洞马蹄焰玻璃池窑

用理论和实践经验相结合的方法,采用ＢｏｒｌａｄｎＣ＋＋语言设计了一个燃油蓄热室流液洞马蹄焰玻璃池窑,用ＡｕｔｏＣＡＤ１２．０版软件包绘制了三张窑炉图（平面图、横剖面图、纵剖面图）。     

外源基因（bar）在转基因燕麦（AvenasativaL.）后代中的遗传与表达

通过微弹轰击获得的含有ｂａｒ基因的转基因燕麦植株自交产生转基因后代。利用ＰＣＲ方法检测ｂａｒ基因在后代中的传递情况。     

弱酸性介质中Silicalite—1分子筛膜的制备与表征

在ＳｉＯ２－ＴＰＡＢｒ－ＮＨ４Ｆ－Ｈ２Ｏ弱酸性氟离子体系中,在玻璃基片上采用水热晶化法制备了Ｓｉｌｉｃａｌｉｔｅ－１（全硅ＺＳＭ－５）分子筛膜．通过ＸＲＤ,ＳＥＭ分析测试手段对所合成的分子筛膜进行了表征,并对膜合成中硅源,水量等影响因素进行了考察．     

天然食品抗氧化剂-黄酮类化合物

综述了黄酮类化合物作为食品抗氧化添加剂的可能性、作用机理及效构关系,并对黄酮类化合物作为食品添加剂的开发前景作了简要评述。     

图像去噪的几种方法分析比较

图像去噪是图像处理中的重要组成部分，对均值滤波、中值滤波、维纳滤波和图像小波域滤波四种用于图像去噪的平滑技术进行分析比较。