Tourist management in national parks in the Czech-German borderland:Bohemian ’Switzerland’ and Saxon‘Switzerland’

In the article tourist management in two national parks in the Czech-German borderland are being compared,namely Bohemian ’Switzerland’(also known as Czech ’Switzerland’) and Saxon’Switzerland’.Situated on either side of the state border,they feature the same type of geographical environment.Transport accessibility,transborder links and the hiking trail network are analyzed using methodology sourced from graph theory.The result of the analyses is a classification of tourist hubs and tourist centers,as well as an indication of the main directions of tourist flow.The German national park is decidedly more accessible but with a detrimental effect on the natural environment primarily due to its fragmentation by a dense network of tourist trails.In both parks trails enter the core zone(in theory a strict protection area) but this occurs on a larger scale on the German side.In the Czech national park a greater number of positive examples of managing tourist movements can be identified.Additionally,larger areas managed for dispersion,or from which tourists are generally excluded,are located there.

现代音乐表现中古典音乐元素之美——以皇后乐队《Bohemian Rhapsody》为例

本文通过对古典音乐与现代音乐元素演绎浅析,以对比性探究其现代音乐与古典音乐表现内涵之美,以皇后乐队的作品《Bohemian Rhapsody》中对古典元素、古典音乐手法、现代音乐技术的运用,进行实例分析,以探究现代音乐的创作过程中,基于古典音乐和现代音乐技巧以及相互融合技巧的使用为切入点。结合阅读文献史料,浅析音乐创作发展历程,对中国现代音乐创作与市场结合及应用更深层次的了解与感知,为现代音乐的发展衍生一点学术基养。

Lead isotope evolution of the Central European upper mantle:Constraints from the Bohemian Massif

The Pb isotope composition of the upper mantle beneath Central Europe is heterogeneous due to the subduction of regionally contrasting material during the Variscan and Alpine orogenies.Late Variscan to Cenozoic mantlederived melts allow mapping this heterogeneity on a regional scale for the last ca.340 Myr.Late Cretaceous and Cenozoic anorogenic magmatic rocks of the Bohemian Massif(lamprophyres,volcanic rocks of basanite/tephrite and trachyte/phonolite series) concentrate mostly in the Eger Rift.Cretaceous ultramafic lamprophyres yielded the most radiogenic Pb isotope signatures reflecting a maximum contribution from metasomatised lithospheric mantle,whereas Tertiary alkaline lamprophyres originated from mantle with less radiogenic ^(206)Pb/^(204)b ratios suggesting a more substantial modification of lithospheric source by interaction with asthenosphericderived melts.Cenozoic volcanic rocks of the basanite/tephrite and trachyte/phonolite series define a linear mixing trend between these components,indicating dilution of the initial lithospheric mantle signature by upwelling asthenosphere during rifting.The Pb isotope composition of Late Cretaceous and Cenozoic magmatic rocks of the Bohemian Massif follows the same Pb growth curve as Variscan orogenic lamprophyres and lamproites that formed during the collision between Laurussia,Gondwana,and associated terranes.This implies that the crustal Pb signature in the post-Variscan mantle is repeatedly sampled by younger anorogenic melts.Most Cenozoic mantle-derived rocks of Central Europe show similar Pb isotope ranges as the Bohemian Massif.

Βedrock instability of underground storage systems in the Czech Republic, Central Europe

Underground storage systems are currently being used worldwide for the geological storage of natural gas （CH4）, the geological disposal of CO2, in geothermal energy, or radioactive waste disposal. We introduce a complex approach to the risks posed by induced bedrock instabilities in deep geological underground storage sites. Bedrock instability owing to underground openings has been studied and discussed for many years. The Bohemian Massif in the Czech Republic （Central Europe） is geologically and tectonically complex. However, this setting is ideal for leaming about the instability state of rock masses. Longterm geological and mining studies, natural and induced seismicity, radon emanations, and granite properties as potential storage sites for disposal of radioactive waste in the Czech Republic have provided useful information. In addition, the Czech Republic, with an average concentration radon of 140 Bq m-3, has the highest average radon concentrations in the world. Bedrock instabilities might emerge from microscale features, such as grain size and mineral orientation, and microfracturing. Any underground storage facility construction has to consider the stored substance and the geological settings. In the Czech Republic, granites and granitoids are the best underground storage sites. Microcrack networks and migration properties are rock specific and vary considerably. Moreover, the matrix porosity also affects the mechanical properties of the rocks. Any underground storage site has to be selected carefully. The authors suggest to study the complex set of parameters from micro to macroscale for a particular place and type of rock to ensure that the storage remains safe and stable during construction, operation, and after closure.

Bohemian Microdiamonds:Diamond-forming Media and Carbon Source

The Variscan Bohemian Massif in Central Europe,resulting from continent-continent collision,was long considered a potential UHP terrain due to numerous occurrences of high-pressure granulites,eclogites and

在捷克西Bohemian地区乙型肝炎病毒传播的实验流行情况

目的:评价1976—1997年乙肝病毒的趋势。材料和方法:对在870000人群中报告的2568例乙肝病毒回顾性分析已完成。也对实际免疫接种计划作了评价。结果:1976年—1997年间,报告的发病率从23/十万下降到2.8/十万。在调查期间,医院感染和职业感染各年龄组的发病数显著下降。然而。