Small-scale fluctuations of magnetic and electric components of the ELF and VLF wave fields in the sub-auroral topside ionosphere : stochastic characteristics of the wave field

When the Interkosmos-14 and Interkosmos-19 satellites crossed the region of spatially varying electron concentration in the topside ionosphere adjacent to the high-latitude boundary of the main ionospheric trough, it was discovered that there were simultaneous fluctuations of plasma density, temperature and the amplitudes (H_x and E_y) of the ELF and VLF radio/plasma emissions. The probability characteristics of the naturally perpendicular H_x and E_y fluctuations are analysed. The correlation coefficient R(_H, E_y) turned out to be less than 0.6 at frequencies of F ⩽ 4.65 kHz, while at higher frequencies R increases, up to 0.9 at 15 kHz. The following interpretations are proposed:

1. 1.1. While measuring noise emissions, as a rule a mixture of numerous elementary waves is recorded.
2. 2.2. At frequencies exceeding the local lower hybrid resonance frequency (in our case f_LHR ≈ 5 kHz), a mixture of electromagnetic waves experiencing the influence of the inhomogeneous electron concentration N_e is registered.
3. 3.3. At frequencies which are lower than the local value f_LHR the mixture mainly consists of ELF waves. The wave field has a complicated structure, and the dynamical coherence between electric and magnetic field components is not as simple as at VLF frequencies (f ≈ 15 kHz).
4. 4.4. It is shown that the wave components for a mixture of electromagnetic and electrostatic waves (for instance a mixture of VLF and lower hybrid frequency waves) have a lower correlation coefficient because the electrostatic waves are unrelated to the electromagnetic waves.
5. 5.5. The correlation analysis offers an opportunity to detect the presence of waves of various types in the wave mixture.

     

Some aspects of change in flaked stone industries of the mesolithic and neolithic in Southern Britain

In a recent article, one of the writers suggested that the traditional bipartite division of the British Mesolithic, based on consideration of microlith types, was reflected in the shape of waste flakes (Pitts, 1978a). Four early assemblages were dominated by narrow flakes, in contrast to three later ones with a higher representation of broader flakes. In this paper, the originally tentative conclusions are explored in greater detail, and the next major boundary, the start of the Neolithic, is investigated. Related changes in the tool components are also examined and the outlines of an explanatory framework are proposed.     

中国学者笔下的东北亚国际关系史——评黄定天著《东北亚国际关系史》

最近由中国社会科学院中国边疆史地研究中心主编、黑龙江教育出版社出版的中国边疆史地丛书之一、黄定天先生所的《东北亚国际关系史》,向我们揭示了东北亚的过去．中国等东北亚主要国家在近代历史上从荣到衰的重要导因和东北亚国际关系的演变与东北亚各国经济的关联。     

《后汉书》对研究西汉以前政区地理的史料价值及相关文献学问题

南朝刘宋范晔撰著的《后汉书》本纪和列传,配以西晋司马彪《续汉书》诸志,是研治东汉一朝史事最为重要的基本史料。惟研究西汉以及汉代以前各个时期的地理问题,范晔《后汉书》和包括《郡国志》在内的《续汉书》诸志,同样具有很多《汉书·地理志》以及《史记》和《汉书》其他部分所不具备的独特史料价值。     

Some churches of the Anglo-Saxon missionaries in southern Germany: a review of the evidence

An historical introduction outlines the main events in the lives of the principal missionaries – Willibald, Wynnebald, Waldburga, Sola – during the central years of the eighth century, and argues that Willibald was consecrated bishop of Erfurt. A review of the topographical and archaeological evidence concentrates on Eichstätt, whose street pattern reveals the layout of the early town and monastery; new interpretations are suggested for unusual features uncovered by excavation at the cathedral/monastery site. The excavations at Solnhofen are similarly re-examined. Overall, no substantial evidence is found for Anglo-Saxon influence on the church archaeology of the area.     

对我国旅游产品开发操作中若干问题的思考

本文认为“大旅游产品“观和“形象-市场-资源综合导向型“开发观是保证旅游产品合理开发、有效用的理念基础,并提出旅游产品开发操作的原则、基本思路和途径.     

林则徐《壬寅日记》对研究西北地区地理人文的史学价值

《壬寅日记》是林则徐在清道光二十二年由陕西进入新疆时所写的见闻录,记载了西北地区的地理名称、山川关隘、气候特征、物产矿藏、生活习俗等风土人情,日记内容丰富翔实,为研究清代后期西北地区的地理人文保留下了大量珍贵的史料。     

李约瑟《中国科学技术史》引译古代史料错讹举要

李约瑟《中国科学技术史》是一部享誉世界,功贯全球的著作。古籍史料的翻译错误是其白璧微瑕,为使其更加完美,就古籍翻译的三个问题进行商榷。其一,古籍数词的翻译错误;其二,古文献人名的断译错误;其三,古史书的校勘标点错误。     

Spain's and Poland's Road to NATO: the problem of continuity and change in the foreign policy of a democratising state

The aim of this article is to compare the Spanish and Polish road to NATO from the perspective of the shape of the foreign policy and its possible restructuring in states undergoing the process of democratic transformation. The study of both cases shows that the reorientation of the foreign policy of a democratising state results to a large extent from external conditions at the global and regional levels although the internal conditions may hinder or accelerate the reorientation. The example of Spain demonstrates that in a firm and stable international system (the bipolar system) it is extremely difficult to change the direction of foreign policy, even if there are internal premises such as democratisation, well-organised opposition supporting the change and social support. In the case of Poland, the flexible and unstable international system made it possible to radically change the direction of its foreign policy. The existing internal premises without the appropriate external context would not have been enough to generate the reorientation of foreign policy. The comparative study of Spanish and Polish cases should be treated as an introduction to the broader analysis on the subject of the restructuring of foreign policy in the democratising state. Democratic transformation processes which took place in Europe from the mid-1970s provide broad empirical material for further scientific work in this area.     

A simple method for calculating the prevalence of disease in a past human population

A simple method for calculating the prevalence of disease in a past human population is described with particular reference to osteoarthritis. It can be applied to diseases other than osteoarthritis, and should prove particularly useful when studying the epidemiology of other diseases which affect numerous sites within the body and where the overall prevalence cannot be obtained simply by adding the prevalences of the individual sites, because more than one may be affected in the same skeleton. Copyright © 2004 John Wiley & Sons, Ltd.     

Egyptian faience glazing by the cementation method part 2: cattle dung ash as a possible source of alkali flux

Based on our current awareness, there are three distinct primary sources of alkali flux in the ancient Egyptian faience making: natron, soda rich plant ash and the so-called ‘mixed alkali fluxes’. Whereas the nature and origin of the first two types are identified to some extent, there are more questions regarding mixed alkali fluxes. In an attempt to provide further clarification on the latter source, a series of replication experiments on the production of Egyptian faience by the cementation glazing method were conducted using cattle dung ash as the source of alkali flux. After firing at 980 °C, the appearance of the faience objects, the microstructure and the chemical composition of selected samples obtained using scanning electron microscopy/energy-dispersive spectroscopy (SEM-EDS) were investigated. The discussion has primarily focused on cattle dung ash as the most, or one of the most, available sources of ash in ancient societies and its possible use as a source of alkali flux in the production of Egyptian faience, at least by the cementation glazing method.     

The serotonin hypothesis of schizophrenia: a historical case study on the heuristic value of theory in clinical neuroscience

Clinical examination of the reliability and coherence of the evidence concerning modern neurochemical theories of mental disorders has led some scholars to conclude that support for many of these theories is weak. Nevertheless, these theories continue to be widely promoted. One explanation that has been offered for continued adherence to questionable theory is that it stimulates and gives direction to research. The heuristic value of theory is examined in the present paper by tracing the discoveries that followed from an old theory of schizophrenia, which is--by current consensus--false. It is shown that the original serotonin hypothesis of schizophrenia did, in fact, lead to significant advances in neuropharmacology, neurology and psychiatry.