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Transient transport processes in deformable porous media

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Chinese Physics B 2011年第11期20卷 167-175页

作者： cs.Mészáros A.Bálint Szent István University Department of Physics and Process Control Szent István University Department of Chemistry and Biochemistry

The basic partial differential equations relevant for convection-diffusion and convection-diffusion-wave phenomena arc presented and solved analytically by using the MAPLE symbolic computer algebra system. The possible general nonlinear character of the constitutive equation of the convection-discussion process is replaced by a direct posteriori stochastic refinement of its solution represented for Dirichlet-type boundary conditions. A thermodynamic analysis is performed for connecting the relaxation time constants and Jacobi-determinants of deformations at transient transport processes. Finally, a new procedure for general description of coupled transport processes on the basis of the formalism originally developed for convection-free phenomena is presented by matrix analysis methods in the Fourier space.

关键词： convection binary mixtures relaxation time matrix polynomials

Crystal field and magnetism with Wannier functions: rare-earth doped aluminum garnets

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Journal of Rare Earths 2015年第12期33卷 1316-1323页

作者： Eva Mihóková Pavel Novák Valentin V.Laguta Institute of Physics Czech Academy of Sciences

Using the recently developed method we calculated the crystal field parameters m yttrium anct lutetium aluminum garnets doped with seven trivalent Krarners rare-earth ions. We then inserted calculated parameters into the atomic-like Hamiltonian taking into account the electron-electron, spin-orbit and Zeeman interactions and determined the multiplet splitting by the crystal field as well as magnetic tensors. We compared calculated results with available experimental data. Very good agreement with the spectroscopic data and qualitative agreement with experimental tensors was found.

关键词： crystal field ab initio calculations gamets rare earths

Forest Disturbance Enhanced the Activity of Epedaphic Collembola in Windthrown Stands of the High Tatra Mountains

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Journal of Mountain Science 2014年第2期11卷 449-463页

作者： Veronika URBANOVIOVá Dana MIKLISOVá Lubomír ková Institute of Biology and Ecology Faculty of Science P.J. Safárik UniversityMoyzesova 11 Kosice 04001 Slovakia Institute of Parasitology Slovak Academy of SciencesHlinkova 3 Kosice 04001 Slovakia

The study aimed to assess the response of ep- and hemiedaphic Collembola communities(activity, richness, community structure) to a disturbance, the subsequent management regime and to the season(summer, winter) in a High Tatra Mountains spruce forest destroyed by a *** and clear-cut resulted in an initial increase in the activity of Collembola inhabiting open areas,opportunistic or generalist species, while forest specialists diminished in numbers or *** results indicated that treatment with nonextracted fallen trees(NEX) provided a better chance for forest species to survive compared with their survival in open habitats of extracted(EXT) and wildfire(FIR) treatments. great species' potential of NEX treatment was indicated by Chao2 estimator and activity/species rarefaction curves. Communities of NEX treatment were more similar to the reference(REF) treatment, documented by ordination and cluster analyses. Thus, leaving fallen timber after a windthrow to natural process of succession is suitable for survival of forest species and maintenance of diversity in forests restoration than timber *** structure in wildfire(FIR) stands was the most dissimilar to the other treatments. Most of the species trapped in this treatment belonged to hemiedaphic life forms, while the activity of larger epedaphic species diminished. In contrast, the highest number of trapped Collembola in EXT treatment was connected with the larger-bodied epigeic species with fast dispersal ability. The trapping period affected both the number of individuals and species richness;Collembola activity and species diversity in the individual treatments were lower in winter compared with the summer period. Several species increased activity during the winter period, namely Folsomia penicula, Friesea mirabilis, F. truncata, Hypogastrura socialis and Protaphorura aurantiaca.

关键词： Wildfire Windstorm Clear-cutting Collembola Spruce forest

The cis-trans Isomerisation of Homologous 2-Hydroxycycloalkanecarboxylic Acids under Basic Conditions

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Chinese Journal of Chemistry 2006年第12期24卷 1792-1795页

作者： gYARMATI cs. Zsuzsanna PALINKO lstván BOKROS Attila MARTINEK A. Tamás BERNATH gábor Institute of Pharmaceutical Chemistry University ofSzeged Szeged POB 121 H-6701 Hungary Research group for Heterocyclic Chemistry of the Hungarian Academy of Sciences and University of Szeged Szeged POB 121 H-6701 Hungary Department of Organic Chemistry University of Szeged Szeged Ddm tér 8 H.6720 Hungary

The cis→trans isomerisation of homologous 2-hydroxycycloalkanecarboxylic acids in strongly basic aqueous solution was studied starting from the cis isomers. It was found that the cyclopentane, cyclohexane and cycloheptane homologues afforded synthetically useful amounts of the trans acids and the procedure resulted in relatively small quantities of the corresponding olefinic acids. In contrast, the isomerisation of the cis-2-hydroxycyclooctanecarboxylic acid produced roughly equal amounts of the cis and trans isomers and the 1-cyclooctenecarboxylic acid at equilibrium. Molecular modelling with the PM3 semiempirical method of the reactants, products and the intermediates applying explicit water molecules as reaction medium gave a fair estimate for the rate sequence of the idealised （dehydration-free） isomerisation reactions in aqueous base solution.

关键词： geometric isomerisation base catalysis reaction mechanism molecular modelling

Arylation of Allylic Alcohols with Aryl Iodides Catalyzed by a Silica-Bound Bidentate Sulfur Palladium (0) Complex

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Chinese Chemical Letters 1998年第5期9卷 427-430页

作者： Cai, MZ Song, cs Huang, X Hangzhou Univ Dept Chem Hangzhou 310028 Peoples R China Jiangxi Normal Univ Dept Chem Nanchang 330027 Peoples R China

Allylic alcohols react with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound bidentate sulfur palladium (0) complex to form 3-arylaldehydes or ketones in good yields.

关键词： supported palladium catalyst arylation allylic alcohol sulfur palladium complex

A New Lignan glucoside from Lancea tibetica

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Chinese Chemical Letters 1999年第1期10卷 37-38页

作者： Su, BN Yuan, cs Jia, ZJ Lanzhou Univ Natl Lab Appl Organ Chem Dept Chem Lanzhou 730000 Peoples R China

A new 7-9'-monoepoxy tetrahydrofuran type lignan glucoside with the cis-relationship of H-7 and H-8, named tibeticoside A 1, was isolated from the medicinal whole plants of Lancea tibetica. Its structure was elucidate... 详细信息

关键词： Lancea tibetica scrophulariaceae tibeticoside A

Microstructure and Deformation Behavior of Ti-10V-2Fe-3Al Alloy during Hot Forming Process

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Journal of Wuhan University of Technology(Materials Science) 2015年第6期30卷 1332-1337页

作者：管仁国 ZHAO Zhanyong Choi KS Lee cs Key Laboratory of Electromagnetic Processing of Materials of Ministry of Education Northeastern University College of Materials Science and Engineering Northeastern University Materials and Metallurgical School Pohang University of Science and Technology

The microstructure evolution and formability of Ti-10V-2Fe-3Al alloy related to the initial microstructures and processing variables were investigated during hot forming process. The experimental results show that the α-phase growth is controlled by solute diffusion during the heat treatment processes. Four different microstructures were established by combinations of several heat treatments, and Ti-10V-2Fe-3Al alloy shows excellent formability both above and below the β transus temperature. The alloy possesses low deformation resistance and active restoration mechanism during the deformation. A constitutive equation describing the hot deformation behavior of Ti-10V-2Fe-3Al alloy was obtained. Higher fl ow stress was observed for the acicular morphology of α phase in microstructures with large aspect ratios as compared with that of small aspect ratios. Due to the dynamic recovery in soft β phase, and the dynamic recrystallization and breakage of acicular α-phase, fl ow softening occurred signifi cantly during deformation. Dynamic recrystallization also occurred especially in the severely deformed regions of forged parts.

关键词： Ti-10V-2Fe-3Al alloy microstructure evolution hot forging constitutive equation recovery dynamic recrystallization

Limsup Results and LIL for Partial Sum Processes of a gaussian Random Field

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Acta Mathematica Sinica,English Series 2008年第9期24卷 1497-1506页

作者： Yong-Kab CHOI Mikls csRg Department of Mathematics and RINS Gyeongsang National University Jinju 660-701 Republic of Korea School of Mathematics and Statistics Carleton University 1125 Colonel By DriveOttawa K1S 5B6 Canada

Let {ξ j ; j ∈ ℤ+ d be a centered stationary gaussian random field, where ℤ+ d is the d-dimensional lattice of all points in d-dimensional Euclidean space ℝd, having nonnegative integer coordinates. For each j = (j 1 , ..., jd) in ℤ+ d , we denote |j| = j 1 ... j d and for m, n ∈ ℤ+ d , define S(m, n] = Σ mζ j , σ2(|n−m|) = ES 2 (m, n], S n = S(0, n] and S 0 = 0. Assume that σ(|n|) can be extended to a continuous function σ(t) of t > 0, which is nondecreasing and regularly varying with exponent α at b ≥ 0 for some 0 garithm for such partial sum processes.

关键词： stationary gaussian random field regularly varying function large deviation probability law of the iterated logarithm

Development of an ultrathin liquid sheet target for laser ion acceleration at high repetition rates in the kilohertz range

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High Power Laser Science and Engineering 2024年第3期12卷 134-145页

作者： M.Füle A.P.kovács T.gilinger M.Karnok P.gaál S.Figul g.Marowsky K.Osvay National Laser-Initiated Transmutation Laboratory University of SzegedSzegedHungary Department of Experimental Physics University of SzegedSzegedHungary ELI ALPS ELI-HU Non-Profit Ltd.SzegedHungary Department of Optics and Quantum Electronics University of SzegedSzegedHungary Advanced Microfluidic Systems gmbH GöttingenGermany

A colliding microjet liquid sheet target system was developed and tested for pairs of round nozzles of 10,11 and 18μm in *** sheet's position stability was found to be better than a few *** interaction with 50 mJ laser pulses,the 18μm jet has a resonance amplitude of 16μm at a repetition rate of 33 Hz,while towards 100 Hz it converges to 10μm for all nozzles.A white-light interferometric system was developed to measure the liquid sheet thickness in the target chamber both in air and in vacuum,with a measurement range of 182 nm±1μm and an accuracy of±3%.The overall shape and 3D shape of the sheet follow the Hasson±Peck model in *** vacuum versus air,the sheet gradually loses 10%of its thickness,so the thinnest sheet achieved was below 200 nm at a vacuum level of 10±4mbar,and remained stable for several hours of operation.

关键词： diagnostics laser ion acceleration nanometric liquid sheet targets vacuum test