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211.
Grant Cairns Sebastian Jambor 《Proceedings of the American Mathematical Society》2008,136(11):3803-3807
We give explicit formulas for the cohomology of the Heisenberg Lie algebras over fields of finite characteristic. We use this to show that in characteristic two, unlike all other cases, the Betti numbers are unimodal.
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A laser-plasma EUV source is described, which is going to be utilized for characterization of EUV optical components and sensoric devices in the wavelength region from 11 to 13 nm. EUV radiation is generated by focusing a Nd:YAG laser into a double stream gas puff target. By the use of different target gases, broadband as well as narrow-band EUV radiation can be obtained. The emission characteristics of the radiation is monitored by the help of different diagnostic tools including a pinhole camera, an EUV spectrometer, and various EUV photodiodes, either directly or after reflection from multilayer mirrors. Theoretical calculations of collision-induced energy transfer are given in order to explain the observed high degree of electronic excitation in the utilized target gases. 相似文献
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Pedro J. Catuogno Sebastian E. Ferrando Alfredo L. Gonzalez 《Journal of Fourier Analysis and Applications》2008,14(5-6):712-743
H-systems are those orthonormal systems which allow computation of conditional expectations via a Fourier expansion. These systems provide natural approximations to continuous stochastic processes and we indicate how they could be used to perform lossy compression on a set of given signals. More specifically, we show how to construct, for a given random variable, an adaptive martingale approximation by means of generalized Haar functions. We also indicate how the construction can be extended to a given random vector. A generalized multiresolution analysis algorithm is also described and numerical examples are provided. 相似文献
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Reyhaneh Armin Sebastian Zühlke Gisela Grunewaldt-Stcker Felix Mahnkopp-Dirks Souvik Kusari 《Molecules (Basel, Switzerland)》2021,26(12)
Apple Replant Disease (ARD) is a significant problem in apple orchards that causes root tissue damage, stunted plant growth, and decline in fruit quality, size, and overall yield. Dysbiosis of apple root-associated microbiome and selective richness of Streptomyces species in the rhizosphere typically concurs root impairment associated with ARD. However, possible roles of Streptomyces secondary metabolites within these observations remain unstudied. Therefore, we employed the One Strain Many Compounds (OSMAC) approach coupled to high-performance liquid chromatography-high-resolution tandem mass spectrometry (HPLC-HRMSn) to evaluate the chemical ecology of an apple root-associated Streptomyces ciscaucasicus strain GS2, temporally over 14 days. The chemical OSMAC approach comprised cultivation media alterations using six different media compositions, which led to the biosynthesis of the iron-chelated siderophores, ferrioxamines. The biological OSMAC approach was concomitantly applied by dual-culture cultivation for microorganismal interactions with an endophytic Streptomyces pulveraceus strain ES16 and the pathogen Cylindrocarpon olidum. This led to the modulation of ferrioxamines produced and further triggered biosynthesis of the unchelated siderophores, desferrioxamines. The structures of the compounds were elucidated using HRMSn and by comparison with the literature. We evaluated the dynamics of siderophore production under the combined influence of chemical and biological OSMAC triggers, temporally over 3, 7, and 14 days, to discern the strain’s siderophore-mediated chemical ecology. We discuss our results based on the plausible chemical implications of S. ciscaucasicus strain GS2 in the rhizosphere. 相似文献
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Sebastian Mendrek Aleksandra Mendrek Hans‐Juergen Adler Andrzej Dworak Dirk Kuckling 《Journal of polymer science. Part A, Polymer chemistry》2009,47(7):1782-1794
Block copolymers of poly(glycidol)‐b‐poly(4‐vinylpyridine) were obtained by ATRP of 4‐vinylpyridine initiated by ω‐(2‐chloropropionyl) poly(glycidol) macroinitiators. By changing the monomer/macroinitiator ratio in the synthesis polymers with varied P4VP/PGl molar ratio were obtained. The obtained block copolymers showed pH sensitive solubility. It was found that the linkage of a hydrophilic poly(glycidol) block to a P4VP influenced the pKa value of P4VP. DLS measurements showed the formation of fully collapsed aggregates exceeding pH 4.7. Above this pH values the collapsed P4VP core of the aggregates was stabilized by a surrounding hydrophilic poly(glycidol) corona. The size of the aggregates depended significantly upon the composition of the block copolymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1782–1794, 2009 相似文献