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2. Co-occurrence and microhabitat of Ancyrocephalus mogurndae (Monogenea) and Henneguya weishanensis (Myxosporea) on gills of the mandarin fish, Siniperca chuatsi

Creator:
Nie, Pin
Format:
print
Type:
model:internalpart and TEXT
Subject:
Ancyrocephalus mogurndae, Henneguya weishanensis, Siniperca chuatsi, monogenean, myxosporean, parasite population, seasonality, and microhabitat distribution
Language:
English
Description:
Seasonal variations in a population of the monogenean Ancyrocephalus mogurndae Gussev, 1955 were investigated on gills of cage-cultured mandarin fish, Siniperca chuatsi (Basilewsky), during the period from April 1994 to April 1995. The abundance of A. mogurndae peaked in late spring and summer. Prevalence was high (75-100 %) throughout the study period, and did not vary significantly between months. More than 50 % of all monogeneans were found on the first and second gill arches, except one occasion when the fourth gill arch had the majority in April 1995. The niche breadths were significantly correlated with the population abundance. A coexistent parasitic myxosporean, Henneguya weishanensis Hu, 1965, on the gills of the fish was found to have little influence on the gill-arch preference of the monogenean, although the monogenean abundance was higher in those fish infected with the myxosporean.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Tepelná čočka v aktivním prostředí pevnolátkových laserů při nízkých teplotách

Creator:
Veselský, Karel, Šulc, Jan, Jelínková, Helena, Nejezchleb, Karel, and Škoda, Václav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
thermal lens, low temperatures, high-power lasers, diod-pumped solid-state lasers, tepelná čočka, nízké teploty, vysokovýkonné lasery, and diodově čerpané pevnolátkové lasery
Language:
Czech
Description:
In this paper we present the effect of low temperatures on the size of the thermal lensin the active medium ofsolid-state lasers. Thermal effects are the main limiting factor of high-power laser systems. One possibility of minimizing thermal effects is the cooling of the active medium at cryogenic temperatures, which has a major impact on material properties - thermal conductivity, coefficient of thermal expansion and thermo-optic coefficient, which determine their nature. In addition to temperature, these parameters depend on the concentration of active ions. By measuring the optical power of the thermal lens we can determine the effect of the temperature of the crystal and the concentration of active ions to the magnitude of these parameters. In the article we compare experimentally dependence of the thermal lens on the temperature of active medium for crystals Yb: YAG and Yb new material: LuAG at low temperatures and the results are compared with a simple physical model. and V tomto článku je prezentován vliv nízkých teplot na velikost tepelné čočky v aktivním prostředí pevnolátkových laserů. Tepelné efekty jsou hlavním omezujícím faktorem vysokovýkonných laserových systémů. Jednou z možností jejich minimalizování je ochlazení aktivního prostředí na kryogenní teploty, což má zásadní vliv na materiálové parametry - tepelnou vodivost, koeficient teplotní roztažnosti a termooptický koeficient, které určují jejich povahu. Kromě teploty jsou tyto parametry závislé i na koncentraci aktivních iontů. Měřením optické mohutnosti tepelné čočky lze stanovit vliv teploty krystalu a koncentrace aktivních iontů na velikost těchto parametrů. V článku jsou experimentálně porovnány závislosti tepelné čočky na teplotě aktivního prostředí pro krystaly Yb:YAG a nový materiál Yb:LuAG při nízkých teplotách a výsledky jsou porovnány s jednoduchým fyzikálním modelem.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Těšínské stříbrné krojové šperky

Creator:
Branna, Wieslawa
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Silesia, Těšínsko, jewellery, folk costume, and arts and crafts production
Language:
Czech
Description:
For many years, the attention of specialists has been aimed at Těšín folk costumes decorated with silver jewellery. They are the result of a gradual diffusion of city jewellers’ products among wealthier countrymen; amateur craftsmen (so called fušeři - dabblers) used to make jewellery for less wealthy people. Jablunkov and Těšín were main centres of this production. Jewellery was primarily made of silver, but copper, tin, lead and later new materials (German silver) were used as well. The most common methods of making silver jewellery were casting (the oldest technology), extrusion and filigree. There are following types of jewellery: hooks, belts, buttons, chains, necklaces and different brooches. Grotesque, arabesque, auriculated and also zoomorphic (lion, bird, lamb) and anthropomorphic (king David, angel) ornaments prevail on the oldest jewellery. Silver belts became the height of art and craftsmanship of Těšín jewellers’ work. The most extensive and comprehensive collection of Těšín silver folk costume jewellery is owned by the Museum of Těšínsko in Český Těšín.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public