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Start Over Coverage 267-271

1. 4-dimensional anti-Kähler manifolds and Weyl curvature

Creator:
Kim, Jaeman
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
4-dimensional anti-Kähler manifold, zero scalar curvature, Weyl curvature, and flat
Language:
English
Description:
On a 4-dimensional anti-Kähler manifold, its zero scalar curvature implies that its Weyl curvature vanishes and vice versa. In particular any 4-dimensional anti-Kähler manifold with zero scalar curvature is flat.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Changes of donor and acceptor side in photosystem 2 complex induced by iron deficiency in attached soybean and maize leaves

Creator:
Jiang, Chuang-Dao, Gao, Hui-Yuan, and Zou, Qi
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence kinetics, Glycine max, photosynthesis, and Zea mays
Language:
Multiple languages
Description:
Photosynthesis in iron-deficient soybean and maize leaves decreased drastically. The quantum yield of photosystem 2 (PS2) electron transport (ΦPS2), the efficiency of excitation energy capture by open PS2 reaction centres (Fv'/Fm'), and photochemical quenching coefficient (qP) under high irradiance were lowered significantly by iron deficiency, but non-photochemical quenching (NPQ) increased markedly. The analysis of the polyphasic rise of fluorescence transient showed that iron depletion induced a pronounced K step both in soybean and maize leaves. The maximal quantum yield of PS2 photochemistry (Φpo) decreased only slightly, however, the efficiency with which a trapped exciton can move an electron into the electron transport chain further than QA (Ψ0) and the quantum yield of electron transport beyond QA (ΨEo) in iron deficient leaves decreased more significantly compared with that in control. Thus not only the donor side but also the acceptor of PS2 was probably damaged in iron deficient soybean and maize leaves. and Chuang-Dao Jiang, Hui-Yuan Gao, Qi Zou.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Huffmanela hamo sp. n. (Nematoda: Trichosomoididae: Huffmanelinae) from the dagger-tooth pike conger Muraenesox cinereus off Japan

Creator:
Justine, Jean-Lou and Iwaki, Takashi
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
new species, egg morphology, and Pacific Ocean
Language:
English
Description:
Huffmanela hamo sp. n. is described from eggs only, which were found in black spots in the somatic musculature of a dagger-tooth pike conger, Muraenesox cinereus (Forsskål), caught off Japan. The eggs are 66-77 µm (mean 72 µm) in length and 33-38 µm (mean 35 µm) in width. The surface of the eggs is smooth and bears neither envelope nor filaments. The species is distinguished from other members of the genus by the dimensions of its eggs and the characteristics of their surface. This is the first species of Huffmanela Moravec, 1987 to be described from an anguilliform fish, and the twentieth nominal species in the genus. Similar black spots with eggs were reported four times in ten years from this fish caught off Japan; although eggs could not be examined, it is likely that the same species was involved in all cases.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Stanovení teploty skladování epoxidové pryskyřice pomocí luminiscenční spektroskopie

Creator:
Mikuličová, Michaela and Křesálek, Vojtěch
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fluorescent spectroscopy, epoxy resins, kinetics, fluorescenční spektroskopie, epoxidové pryskyřice, and kinetika vytvrzování
Language:
Czech
Description:
The paper deals with the use of the luminiscence phenomenon of epoxy resins to obtain an estimation of basic technological variables such as the storage temperature of the mixed resin and an estimation of the end of the crosslinking reaction in the state of the material that allows manipulation with the product. To obtain a description of the curing reaction kinetics, it was necessary to measure the fluorescence spectra over time and to create a mathematical model. From the processed data we obtained the value of the highest storage temperature for a particular epoxy system (EPOXY 1200 + P11), when the reaction stops t = -0.7 °C and we also determined the potential barrier value for the given chemical reaction w0 = 158 meV. The obtained results are an interesting possibility to use a non-contact optical method for controlling the curing processes in the production of composite products (e.g. aircraft wings in an autoclave) and their automation. and Článek se zabývá využitím jevu luminiscence u epoxidových pryskyřic k získání odhadu základních technologických veličin, jako jsou teplota skladování zamíchané pryskyřice a odhad ukončení síťovací reakce ve stavu materiálu, který umožňuje manipulaci s výrobkem. Kzískání popisu kinetiky vytvrzovací reakce bylo nutno naměřit fluorescenční spektra v závislosti na čase a následně vytvořit matematický model. Ze zpracovaných dat jsme pro konkrétní epoxidový systém (EPOXY 1200+P11) získali hodnotu nejvyšší skladovací teploty t=-0,7 °C, kdy se reakce zastaví, a navíc jsme určili hodnotu potenciálové bariéry pro danou chemickou reakci w0 = 158 meV. Získané výsledky jsou zajímavou možností využití nekontaktní optické metody pro řízení vytvrzovacích postupů při výrobě kompozitových výrobků (například křídel letadel v autoklávu) a jejich automatizaci.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Techniques for isolating thermotolerant and pathogenic freeliving amebae

Creator:
Jonh, David T. and Howard, Marsha J.
Format:
print
Type:
model:internalpart and TEXT
Subject:
pathogenic freeliving amebae, environmental isolation, Acanthamoeba, Naegleria australiensis, and Naegleria fowleri
Language:
English
Description:
Several conditions of isolation were evaluated to determine which yielded the greatest number of thermotolerant and pathogenic freeliving amebae. Swab samples, easier to obtain and process, produced more pathogenic amebae than water samples. If water samples are required, 50-ml volumes gave the greatest percentage of pathogenic isolates. An incubating temperature of 42"C yielded the most thermotolerant amebae. A total of 11 pathogenic isolates were obtained from 762 environmental samples and were Acanthamoeba (55 %), Naegleria fowleri Carter, 1970 (27 %), and N. australiensis De Jonckheere, 1981(18%).
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Tepelné záření v teoretických i experimentálních úlohách Mezinárodní fyzikální olympiády

Creator:
Kříž, Jan, Volf, Ivo, and Vybíral, Bohumil
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fyzika, fyzikální olympiády, physics, physics olympiads, 6, and 53
Language:
Czech
Description:
I v tomto čísle Československého časopisu pro fyziku přinášíme ukázky úloh pro fyzikální olympioniky. Představíme tentokrát jednu teoretickou a jednu experimentální úlohu z Mezinárodní fyzikání olympiády, jejichž společným jmenovatelem je použití Stefanova-Boltzmannova zákona., Jan Kříž, Ivo Volf, Bohumil Vybíral., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public