This article evaluates once more the historiographic and literary images of John of Bohemia and his son Charles IV in Italian texts from the 14th and early 15th centuries. What we find is a peculiar mixture of criticism and apotheosis, sometimes stated by the same authors, depending on the point in time they were writing, and of course the expectations of their potential readers. While John of Bohemia faced overwhelming expectations from Dante after the death of his father, he was branded a naïve yet greedy papal mercenary from the beginning of his Italian Expedition in the early 1330s. His son was more successful in avoiding negative stereotypes and harsh criticisms during his Italian expeditions in his youth, as well as in 1354/55 and 1368/69. In the end, however, even chroniclers that are traditionally considered to have had a positive view of the Luxemburg king and emperor harshly rejected his political actions in Italy. Most of the time, this is connected with the financial interests all foreign monarchs had when establishing temporary rulerships in Italian cities, and the monetary pressures this bore on their citizens; the worn-out cliché, both of contemporaries and historical researchers, that labelled foreign, Central European monarchs as barbaric intruders, could hardly be confirmed. Charles and his father are blamed for being unable to solve the structural problems of Italian and Imperial politics.
Under normal conditions, electrons are accelerated by electric fields and decelerated by collision processes. After some time, a stable equilibrium between these two processes is achieved and electrons drift with constant speed against the field direction. Such a scheme is called the ohmic regime. At higher speeds or electric fields, the situation may be completely different. Collisions may not be able to compensate for electron acceleration and electrons attain the so called runaway mode. Runaway electrons are detected in the Earth’s magnetosphere during storms, in the solar plasma, and also in laboratory plasmas and in many plasma technologies., Petr Kulhánek., and Obsahuje bibliografii
Výzkum fyziky ubíhajících elektronů se v posledních letech stal jednou z prioritních oblastí výzkumu na tokamacích. V rámci konsorcia EUROfusion, které koordinuje výzkum termojaderné fúze v Evropě, byl náš tým na tokamatu COMPASS v Ústavu fyziky plazmatu AV ČR, v. v. i., před šesti lety vyzván k zařazení studia ubíhajících elektronů do experimentálního programu. Tento článek shrnuje fyzikální motivaci k uvedenému výzkumu, dosažené znalosti a také hlavní výsledky, kterými v tomto směru náš tým přispívá k jistějšímu zvládnutí termojaderného provozu prvních fúzních reaktorů, včetně zařízení ITER., Research in the physics of runaway electrons has become one of the most important fields in current tokamak science. In the framework of the EUROfusion consortium, which coordinates thermonuclear fusion research in Europe, the Institute of Plasma Physics of the CAS was invited, from 2014, to introduce a runaway electron study into the experimental programme of the COMPASS tokamak. This article summarises the motivation for runaway electron research, the achieved knowledge, and also the main results of our team, which may contribute to yet safer thermonuclear operation of the first fusion reactors, including the ITER facility., Jan Mlynář, Jakub Čaloud, Ondřej Ficker, Eva Macúšová, Jaroslav Čeřovský., and Obsahuje bibliografické odkazy
This article is focused on opinions that the literary historian and Custodian of the Prague Imperial-Royal University Library (now the National Library of the Czech Republic) Josef Truhlář (1840-1914) had on Manuscripts of Dvůr Králové and Zelená Hora. Initially, he had been convinced of the authenticity of the Manuscripts, but after Gebauer´s groundbreaking article questioning their authenticity published in the Athenaeum journal in February 1886, he re-evaluated his older opinions and published a series of articles in this journal denying the authenticity of the Manuscripts. These articles were focused on suspicious finding circumstances of these allegedly old monuments, parallels in their texts with literary works from the early 19th century and on other contemporary forged manuscripts.
Střední Evropa byla od 60. let 20. století známa jako místo, kde komíny elektráren chrlily do ovzduší nejvíc oxidu siřičitého na světě. Kyselý déšť zde usmrtil a poničil rozsáhlé porosty lesů. Autor se zaměřuje na otázky, jak vlastně kyselé deště působí a jaká je situace v současnosti poté, co emise oxidu siřičitého v uplynulých letech významně poklesly, kdy ale přetrvává výrazný podíl okyselujících emisí sloučenin dusíku. and Since 1960s Central Europe has been known as the area where industrial plant chimneys released the highest amount of sulphur dioxide in the world and where acid rain destroyed or killed extensive forest growths. The authors explain the effects of acid rain and the present situation now that sulphur dioxide emission levels have significantly declined, but considerable amounts of acidifying emissions of nitrogen substances are still in the environment.
Závěrečná část seriálu se věnuje problematice okyselení povrchových vod vlivem depozice hlavně síry a následnému toxickému působení z půdy uvolňovaného hliníku. V České republice byla acidifikací postižena hlavně horská jezera na Šumavě a též některé potoky v horských oblastech. Autoři srovnávají a objasňuji i rozdílné působení kyselých depozic na lesy a povrchové vody v ČR a ve Skandinávii. and The last part of this series of articles deals with surface water acidification caused particularly by sulphur deposition and with the consequent effects of toxic aluminium released from the soil. In the Czech Republic, mountain lakes in the Šumava/Bohemian Forest Mts. have been particularly affected, as well as some streams in mountain areas. The authors explain the different effects of acid depositions on forests and surface water in the Czech Republic and in Scandinavia.
Přímý dopad SO2 na horské lesy způsobující velkoplošné úhyny se začal snižovat v 90. letech 20. stol. po odsíření hlavních zdrojů SO2. Dlouhodobá půdní acidifikace (okyselení) a nízký poměr bazických iontů (Ca, Mg, K) vůči hliníků v půdě negativně ovlivňují lesy i nadále. I přes prokazatelné snížení atmosférické depozice síry se chronicky projevuje nízká saturace bazickými ionty, hlavně pak v porostech intenzivně lesnicky obhospodařovaných smrkových monokulturách. K tomu přistupuje další hrozba, a to saturace již tak degradovaných půd dusíkem. and In the Czech Republic the direct effect of SO2 on the mountain forests decreased during the 1990s as a result of the desulfurization of large SO2 sources. Chronic soil acidification, nutrient base cations (Ca, Mg, K) depletion and aluminum mobilization has been the most important mechanism behind forest damage since the 1990s. Despite a significant decline in atmospheric deposition, its present level together with high uptake of base cations by Norway Spruce monocultures will not allow significant soil recovery during the next few decades. In addition, critical loads for nutrient nitrogen have been significantly exceeded in mountain forests.