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.     

字符编辑器在CAI课件设计中的开发应用

该文介绍利用字符编辑器设计CAI课件屏幕图形和动画的方法以及TenCORE教学系统字符编辑器的基本原理和使用方法。     

高师《分析化学》教材体系的主要特点及教法试验

本文分析了高师分析化学教材体系主要特点,并提出理论课采用辐射式教学法,实验课采用激发式教学法;用双向引导式教学法,把理论课和实验课教学,有机地联系起来.     

取代[14]轮烯,[18]轮烯和卟吩的异构体计数

用图论方法对取代〔１４〕轮烯、〔１８〕轮烯和卟吩的构造异构和构型异构体数进行计算。计算结果列表表示。     

省道002线（分水岭—仲宫段）地层划分与岩土工程分类

详细阐述了省道002线分水岭到仲宫段跨越地带地层的时代、岩性,划分了岩、土的工程类别,为道路和桥梁设计、支挡物设置及工程概算提供了依据。     

东北特产药用植物—东北龙胆的研究

东北龙胆是我省西部重要资源植物,著名的中药。值得注意的是这一自然资源已经遭到破坏,而且因其种子萌发条件和现有生态环境不一致,看来难以恢复。本文研究了东北龙胆的生态分布,形态解剖特征和生物学特征,以及恢复这一资源的途径和技术关键。本文指出了东北龙胆的某些重要特征:一般生境为“洼中岗”,种子萌发时需光:以赤霉素处理种子经水洗后浮水培养可加快种子萌发并提高发芽率。此外,子叶出现之后约两周以上才出现第一对真叶;根可在切断的根或茎的断面上直接再生而不经过脱分化阶段;新根首先在形成层处发生,如果由于某种原因未能在这里发生,则其次在皮层或其它薄壁组织中发生;在发育节律上的特点是8月末开花,而且一直生长到因霜冻而死。所有这些被揭露的特点。从理论到应用,为这一药用植物的种质保存和资源恢复提供了某种保证。     

Gigantecin: A novel antimitotic and cytotoxic acetogenin,with nonadjacent tetrahydrofuran rings,fromGoniothalamus giganteus (Annonaceae)

Summary Gigantecin (I), a novel tetrahydroxy-di-tetrahydrofuran fatty acid -lactone (acetogenin), was isolated from an ethanolic extract of the stem bark ofGoniothalamus giganteus Hook. f., Thomas (Annonaceae), by means of activity-directed fractionation (brine shrimp lethality test). This new compound is extremely cytotoxic to human tumor cells, inhibits crown gall tumors on potato discs, and is active in an assay designed to detect antimitotic agents (9 ASK).     

A novel mechanism for jumping in the indian ant<Emphasis Type="Italic">Harpegnathos saltator</Emphasis> (Jerdon) (Formicidae,Ponerinae)

The Indian antHarpegnathos saltator may be unique among insects in using its jumping capacity not only as an escape mechanism but also as a normal means of locomotion, and for catching its prey in flight. High-speed cinematography used to analyse the various phases of the jump suggests thatHarpegnathos employs a novel jumping mechanism to mediate these behaviours: namely the synchronous activation of its middle and hindlegs. Electrophysiological recordings from muscles or nerves in pairs of middle and hindlegs show remarkably synchronous activity during fictive jumping, supporting the synchronous activation hypothesis.Harpegnathos is not the only ant to jump, and a cladistic analysis suggests that jumping behaviour evolved independently three times during ant evolutionary history.     

苯甲醛缩氨基硫脲Cu(I)、Zn(Ⅱ)配合物的直接电化学合成

用电化学金属阳极氧化法在非水溶剂中合成了苯甲醛缩氨基硫脲（ＨＬ）与Ｃｕ（Ｉ）、Ｚｎ（Ⅱ）配合物,通过元素分析、红外光谱、紫外光谱、磁矩、摩尔电导等对配合物进行了表征。     

取食天然饲料与人工饲料的大蜡螟Galleria mellonella的生长发育差异比较

在温度为35±1℃、相对湿度为65±5％及全黑暗的条件下,对取食天然饲料和人工饲料的大蜡螟Galleria mellonella(L.)的生长发育进行了观察。在天然饲料中,以中蜂巢脾为食的大蜡螟生长发育最好,意蜂巢脾次之,蜂蜡不能很好地使大蜡螟完成发育。试验采用来源广泛且价格低廉的麸糠、面粉和玉米粉为主要原料配制成人工饲料供大蜡螟取食,与供食中蜂巢脾的大蜡螟比较,蛹重、成虫寿命、产卵量均无显著差异,但幼虫历期明显缩短6.8天。