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排序方式: 共有142条查询结果,搜索用时 125 毫秒
91.
Emre Alkan 《Monatshefte für Mathematik》2011,163(3):249-280
We prove a Lipschitz type summation formula with periodic coefficients. Using this formula, representations of the values at positive integers of Dirichlet L-functions with periodic coefficients are obtained in terms of Bernoulli numbers and certain sums involving essentially the discrete Fourier transform of the periodic function forming the coefficients. The non-vanishing of these L-functions at s = 1 are then investigated. There are additional applications to the Fourier expansions of Eisenstein series over congruence subgroups of \({SL_2(\mathbb{Z})}\) and derivatives of such Eisenstein series. Examples of a family of Eisenstein series with a high frequency of vanishing Fourier coefficients are given. 相似文献
92.
Emre Alkan 《The Ramanujan Journal》2012,29(1-3):385-408
The average value of a certain normalization of Ramanujan sums is determined in terms of Bernoulli numbers and odd values of the Riemann zeta function. The distribution of values and limiting behavior of such a normalization are then studied along subsets of Beurling type integers with positive density and sequences of moduli with constraints on the number of distinct prime factors. 相似文献
93.
Aydan Dag Hatice Sahin Hakan Durmaz Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2011,49(4):886-892
We report an efficient way, sequential double click reactions, for the preparation of brush copolymers with AB block‐brush architectures containing polyoxanorbornene (poly (ONB)) backbone and poly(ε‐caprolactone) (PCL), poly(methyl methacrylate) (PMMA) or poly(tert‐butyl acrylate) (PtBA) side chains: poly(ONB‐g‐PMMA)‐b‐poly(ONB‐g‐PCL) and poly(ONB‐g‐PtBA)‐b‐poly(ONB‐g‐PCL). The living ROMP of ONB affords the synthesis of well‐defined poly(ONB‐anthracene)20‐b‐poly (ONB‐azide)5 block copolymer with anthryl and azide pendant groups. Subsequently, well‐defined linear alkyne end‐functionalized PCL (PCL‐alkyne), maleimide end‐functionalized PMMA (PMMA‐MI) and PtBA‐MI were introduced onto the block copolymer via sequential azide‐alkyne and Diels‐Alder click reactions, thus yielding block‐brush copolymers. The molecular weight of block‐brush copolymers was measured via triple detection GPC (TD‐GPC) introducing the experimentally calculated dn/dc values to the software. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
94.
Cirpan A Alkan S Toppare L Hepuzer Y Yagci Y 《Bioelectrochemistry (Amsterdam, Netherlands)》2003,59(1-2):29-33
Immobilization of invertase in conducting copolymer matrices of 3-methylthienyl methacrylate with pyrrole and thiophene was achieved by constant potential electrolysis using sodium dodecyl sulfate (SDS) as the supporting electrolyte. Polythiophene (PTh) was also used in entrapment process for comparison. Kinetic parameters, Michaelis-Menten constant, K(m), and the maximum reaction rate, V(max), were investigated. Operational stability and temperature optimization of the enzyme electrodes were also examined. 相似文献
95.
E. Alkan A. I. Bonciocat N. C. Bonciocat A. Zaharescu 《Proceedings of the American Mathematical Society》2007,135(3):677-687
We provide some square-free criteria for primitive polynomials over unique factorization domains, which do not make use of derivatives or discriminants. Using some ideas of Ostrowski we establish nonvanishing conditions for determinants of matrices with polynomial entries and deduce square-free criteria for polynomials in several variables.
96.
97.
Haixiang Han Jesse C. Carozza Audra P. Colliton Yuxuan Zhang Zheng Wei Alexander S. Filatov Yu‐Sheng Chen Melisa Alkan Andrey Yu. Rogachev Evgeny V. Dikarev 《Angewandte Chemie (International ed. in English)》2020,59(24):9624-9630
A known trinuclear structure was used to design the heterobimetallic mixed‐valent, mixed‐ligand molecule [CoII(hfac)3?Na?CoIII(acac)3] ( 1 ). This was used as a template structure to develop heterotrimetallic molecules [CoII(hfac)3?Na?FeIII(acac)3] ( 2 ) and [NiII(hfac)3?Na?CoIII(acac)3] ( 3 ) via isovalent site‐specific substitution at either of the cobalt positions. Diffraction methods, synchrotron resonant diffraction, and multiple‐wavelength anomalous diffraction were applied beyond simple structural investigation to provide an unambiguous assignment of the positions and oxidation states for the periodic table neighbors in the heterometallic assemblies. Molecules of 2 and 3 are true heterotrimetallic rather than a statistical mixture of two heterobimetallic counterparts. Trinuclear platform 1 exhibits flexibility in accommodating a variety of di‐ and trivalent metals, which can be further utilized in the design of molecular precursors for the NaMM′O4 functional oxide materials. 相似文献
98.
Emre Alkan 《Journal of Number Theory》2006,118(1):1-14
Given an irrational number α and a sequence B of coprime positive integers with the sum of inverses convergent, we investigate the problem of finding small values of nα, with n B-free. 相似文献
99.
Sibel Alkan Bülent Zeybek Alev Doğan Rahmi Kasımoğulları Yunus Erdoğan Esma Kılıç 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):381-386
Abstract Stoichiometric ionization constants of some pyrazole carboxylic acids [4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic
acid, 4-benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, 4-(ethoxycarbonyl)-1,5-diphenyl-1H-pyrazole-3-carboxylic
acid, 4-(ethoxycarbonyl)-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, 4-(ethoxycarbonyl)-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic
acid] were determined in ethanol–water mixtures of 50, 60, 70% ethanol (v/v) by a potentiometric titration method. Titrations
were performed in an ionic strength of 0.10 M NaCl at 25.0 ± 0.1 °C using an Orion 960 automatic titrator under a nitrogen
atmosphere. Using the potentiometric titration data, ionization constants were calculated in three different ways. The effects
of structure and solvent on the acidity of pyrazole carboxylic acids are also discussed.
Graphical abstract
相似文献
100.
Çiğdem Hopa Mahir Alkan Canan Kazak N. Burcu Arslan Raif Kurtaran 《Transition Metal Chemistry》2009,34(4):403-407
A mononuclear iron(III) complex with 2,6-bis(3,4,5-trimethyl-N-pyrazolyl)pyridine (btmpp) has been synthesized, and characterized by X-ray crystallography, IR, UV–Vis and TGA–DTA methods.
The Fe(III/II) couple was characterized by way of cyclic voltammetry using DMF solvent, where the complex was observed to
have an irreversible behaviour. 相似文献