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131.
MADE is the acronym for the ESPRIT project 6307, whose aim is to develop an object oriented multimedia application development environment. As part of this project the MADE help system is designed to be a distributed hypermedia system with additional support for run-time object monitoring and contextual help. 相似文献
132.
Michal Kleiber Tran Duong Hien Eligiusz Postek 《International journal for numerical methods in engineering》1994,37(19):3291-3308
Finite element formulations for structural sensitivity analysis of non-linear systems with fixed overall shape are discussed. Both the direct differentiation and adjoint variable methods are employed. The resulting sensitivity algorithms are consistent with time integration scheme adopted for solving equilibrium problem. Effectiveness and computational aspects of the procedures are discussed and compared. Numerical algorithms are shown to be readily implemented in existing finite element codes. Large-scale examples illustrate the paper. 相似文献
133.
Svatopluk Zeman Michal Roh
Zdenk Friedl Ale Ri
ka Antonín Ly
ka 《Propellants, Explosives, Pyrotechnics》2010,35(4):339-346
X‐ray crystallographic study of 2,2′,2″,2′′′,4,4′,4″,4′′′,6,6′,6″,6′′′‐dodecanitro‐1,1′ : 3′1″ : 3″,1′′′‐quaterphenyl (DODECA) has been carried out. Nonbonding interatomic distances of oxygen atoms inside of all the nitro groups are shorter than those corresponding to the intermolecular contact radii for oxygen. By means of the DFT B3LYP/6‐31(d, p) method a difference of 136 kJ mol−1 between the X‐ray and DFT structures of DODECA was found. The bearer of the highest initiation reactivity in its molecule in solid phase should be the nitro group at 4′′′‐position, in contrast to those at 2′‐ or 2″‐positions in its isolated molecule. The most reactive nitro group in the DODECA molecule can be well specified by the relationship between net charges on nitro groups and charges on their nitrogen atoms, both of them for the X‐ray structure. The 15N chemical shift, corresponding to this nitro group for the initiation by impact and shock, correlates very well with these shifts of the reaction centers of the other six “genuine” polynitro arenes. 相似文献
134.
Concentration of trace elements in arable soil after long-term application of organic and inorganic fertilizers 总被引:4,自引:0,他引:4
Dharam Uprety Michal Hejcman Jiřina Száková Eva Kunzová Pavel Tlustoš 《Nutrient Cycling in Agroecosystems》2009,85(3):241-252
The Ruzyně Fertilizer Experiment (RFE, the Czech Republic) was established on a permanent arable field (illimerized Luvisol)
in 1955. The effects of long-term application of several organic fertilizers (dung water, farmyard manure, poultry litter)
and mineral N, P and K fertilizers on plant-available (extracted by CaCl2), easily mobilizable (extracted by EDTA), potentially mobilizable (extracted by HNO3) and total concentrations of trace elements were investigated in 2008. Concentrations of all analyzed trace elements in the
applied fertilizers did not exceed the limits permitted by Czech national legislation. Concentrations of As, Cd and Cr were
highest in single superphosphate, those of Cu, Mn and Ni were highest in poultry litter and those of Pb and Zn were highest
in dung water. Poultry litter had the second highest concentration of As and Zn. Poultry litter supplied the soils with considerable
amounts of Cu, Mn and Zn and increased their concentrations in the soil. There was also a significant increase in plant availability
of Mn, Ni and Zn and a decrease in soil pH. Although all fertilizers were applied for five decades, total concentrations of
As, Cr, Cu, Ni, Pb and Zn in soil remained far below Czech legislation limits. For Cu and Zn this was probably due to the
relatively low mean annual application rates of poultry litter. Total Cd concentrations in soil exceeded the legislative limit
even in the control (without any fertilizer inputs) and the effect of treatment was not significant. This indicates that fertilizers
were not the main source of Cd in the experimental area. Therefore, common cropping practices do not induce soil contamination
by trace elements even if they have been applied for more than 50 years. 相似文献
135.
Jiří Pinkas Ivana Císařová Ana Conde Rosa Fandos Michal Horáček Jiří Kubišta Karel Mach 《Inorganic chemistry communications》2009,12(1):11-14
Thermolysis of [TiMe2(η5-C5Me4Ph)2] (4) at 145 °C for 5 h afforded the singly tucked-in paramagnetic titanocene [Ti(III)(η5-C5Me4Ph){η5:η1-C5Me3Ph(CH2)}] (9). In distinction to the singly tucked-in permethyltitanocene [Ti(III)(η5-C5Me5){η5:η1-C5Me4(CH2)}] (1) which was found crystallographically disordered [J.M. Fischer, W.E. Piers, V.G. Young, Jr., Organometallics 15 (1996) 2410] the single crystal X-ray diffraction analysis of 9 afforded molecular parameters with nearly by one order better precision as measured by esd-values. 相似文献
136.
Robert Reiberger Kateina Radilov Michal Kr Vclav Zima Pavel Majer Jií Brynda Martin Dra
ínský Jan Konvalinka Milan Koíek Ale Machara 《International journal of molecular sciences》2021,22(14)
The part of the influenza polymerase PA subunit featuring endonuclease activity is a target for anti-influenza therapies, including the FDA-approved drug Xofluza. A general feature of endonuclease inhibitors is their ability to chelate Mg2+ or Mn2+ ions located in the enzyme’s catalytic site. Previously, we screened a panel of flavonoids for PA inhibition and found luteolin and its C-glucoside orientin to be potent inhibitors. Through structural analysis, we identified the presence of a 3′,4′-dihydroxyphenyl moiety as a crucial feature for sub-micromolar inhibitory activity. Here, we report results from a subsequent investigation exploring structural changes at the C-7 and C-8 positions of luteolin. Experimental IC50 values were determined by AlphaScreen technology. The most potent inhibitors were C-8 derivatives with inhibitory potencies comparable to that of luteolin. Bio-isosteric replacement of the C-7 hydroxyl moiety of luteolin led to a series of compounds with one-order-of-magnitude-lower inhibitory potencies. Using X-ray crystallography, we solved structures of the wild-type PA-N-terminal domain and its I38T mutant in complex with orientin at 1.9 Å and 2.2 Å resolution, respectively. 相似文献
137.
Chi‐Ying Li I‐Wen Lo Yen‐Ping Hsueh Yu‐Ming Chung Shih‐Wei Wang Michal Korinek Yi‐Hong Tsai Yuan‐Bin Cheng Tsong‐Long Hwang Clay C. C. Wang Fang‐Rong Chang Yang‐Chang Wu 《Israel journal of chemistry》2019,59(5):432-438
Pursuing epigenetic manipulation approach in fungi led to the isolation of an unusual coumarin metabolite from fungi. An addition of the histone deacetylase inhibitor, suberohydroxamic acid (SBHA), to the culture medium of Arthrobotrys foliicola induced production of the coumarin‐type secondary metabolite represented by a single intensive peak in the HPLC profile of the ethyl acetate extract. The compound which was identified as 4‐ethyl‐7‐hydroxy‐8‐methyl‐2H‐chromen‐2‐one ( 1 ) was isolated from nature for the first time. Moreover, the investigation on the remaining part of the HPLC profile led to the separation of 6‐ethyl‐2,4‐dihydroxy‐3‐methylbenzaldehyde ( 2 ) and ten 2,5‐diketopiperazine compounds ( 3 – 12 ). The structures of isolates were deduced by their mass and NMR spectroscopic data. The coumarin‐type secondary metabolite ( 1 ) with peculiar smell induced by epigenetic stimulation is found for the first time in the Arthrobotrys species and the family Orbiliaceae. We evaluated 1 for the cytotoxic, anti‐inflammatory, anti‐allergic and nematocidal activities, however, it was found inactive. 相似文献
138.
Martin Trunec Premysl Stastny Jakub Kelar Michal Pazderka 《Ceramics International》2019,45(7):9381-9385
Due to environmental and health aspects, aqueous ceramic slurries are preferred to traditional organic solvent systems in tape casting. An important obstacle associated with the high surface energy of water is poor wetting of aqueous ceramic slurries on polymeric tape carriers. Therefore, we measured the contact angles of an aqueous epoxy-based ceramic slurry on polyethylene terephtalate (PET), polypropylene (PP), polymethyl methacrylate (PMMA), and aluminium-coated polyethylene terephtalate (PET-Al) films and investigated approaches to improving their wetting. We evaluated the effect of plasma treatment of the tape carrier surface on the wetting behaviour and compared it with the effect of adding non-ionic amphiphilic surfactants to the ceramic slurry. The treatment of the tape carrier surface by low-temperature plasma substantially improved the wetting behaviour of aqueous ceramic slurry. The lowest contact angle of 31° was obtained on the PET film. Although the addition of non-ionic surfactants improved both the wetting behaviour of the slurry and the detachment of the polymeric carrier from the ceramic tape even better than the plasma treatment of the carrier surface did, the plasma-treated carriers still present a useful alternative to the surfactants. In the case of the plasma-treated PET carrier the surfactants could be fully eliminated and potential drawbacks related to the use of surfactants could be prevented. 相似文献
139.
Kodym Oldich Hradi Michal 《International Journal on Document Analysis and Recognition》2022,25(1):15-28
International Journal on Document Analysis and Recognition (IJDAR) - Most image enhancement methods focused on restoration of digitized textual documents are limited to cases where the text... 相似文献
140.
Ondřej Jankovský Filip Antončík Tomáš Hlásek Vladimír Plecháček David Sedmidubský Štěpán Huber Michal Lojka Vilém Bartůněk 《Journal of the European Ceramic Society》2018,38(6):2541-2546
YBa2Cu3O7-δ (YBCO) is a well-known high-temperature superconductor. However, its critical current density and thus maximum trapped magnetic field can be improved significantly by introducing the secondary phases (artificial pinning centers). In this contribution, we successfully prepared YBCO single-grain bulks with Y2Ba4CuWO10.8 phase serving as a source of pinning centers. This phase was prepared by solid-state reaction and further refined by milling. In the next step single-grain YBCO bulks with homogeneously distributed Y2Ba4CuWO10.8 were prepared by top-seeded melt growth. Precursors as well as the final product were characterized by XRD, SEM and EDS. The phase composition of YBCO bulks containing Y2Ba4CuWO10.8 was analyzed using Rietveld analysis. Thermal stability of YBCO bulk was studied by STA. Furthermore, PPMS was used to study electrical resistivity and critical current density. Bulk superconducting properties such as levitation force and trapped field ability were also measured. 相似文献