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21.
Independent Directed Triangles in a Directed Graph 总被引:2,自引:0,他引:2
Hong WangRID=""ID="" This research was supported by UIRC SEED GRANTS–KDY 《Graphs and Combinatorics》2000,16(4):453-462
If D is a directed graph of order n≥3 with , then D contains independent directed triangles. Moreover, the condition on the minimum degree is sharp in general.
Revised: April 19, 1999 相似文献
22.
S. GustafsonRID=""ID=""Present address: Courant Institute Mercer St. New York NY USA.¶E-mail: gustaf@cims.nyu.edu I. M. Sigal 《Communications in Mathematical Physics》2000,212(2):257-275
We study the linearized stability of n-vortex (n∈ℤ) solutions of the magnetic Ginzburg–Landau (or Abelian Higgs) equations. We prove that the fundamental vortices (n = ± 1) are stable for all values of the coupling constant, λ, and we prove that the higher-degree vortices (|n|≥ 2) are stable for λ < 1, and unstable for λ > 1. This resolves a long-standing conjecture (see, eg, [JT]).
Received: 16 November 1998 / Accepted: 3 January 2000
RID="*"
ID="*"Research on this paper was supported by NSERC under grant N7901
RID="**"
ID="**"Present address: Courant Institute, 251 Mercer St., New York, NY 10012, USA.¶E-mail: gustaf@cims.nyu.edu 相似文献
23.
K.?S.?Senthil RaaniEmail authorView authors OrcID profile 《Monatshefte für Mathematik》2017,184(3):459-487
Suppose \(\mu \) is an \(\alpha \)-dimensional fractal measure for some \(0<\alpha <n\). Inspired by the results proved by Strichartz (J Funct Anal 89:154–187, 1990), we discuss the \(L^p\)-asymptotics of the Fourier transform of \(fd\mu \) by estimating bounds of for \(f\in L^p(d\mu )\) and \(2<p<2n/\alpha \). In a different direction, we prove a Hardy type inequality, that is, where \(1\le p\le 2\) and \(E_x=E\cap (-\infty ,x_1]\times (-\infty ,x_2]\ldots (-\infty ,x_n]\) for \(x=(x_1,\ldots x_n)\in {\mathbb R}^n\) generalizing the one dimensional results by Hudson and Leckband (J Funct Anal 108:133–160, 1992).
相似文献
$$\begin{aligned} \underset{L\rightarrow \infty }{\liminf }\ \frac{1}{L^k} \int _{|\xi |\le L}\ |\widehat{fd\mu }(\xi )|^pd\xi , \end{aligned}$$
$$\begin{aligned} \int \frac{|f(x)|^p}{(\mu (E_x))^{2-p}}d\mu (x)\le C\ \underset{L\rightarrow \infty }{\liminf }\frac{1}{L^{n-\alpha }} \int _{B_L(0)}|\widehat{fd\mu }(\xi )|^pd\xi \end{aligned}$$
24.
IA Simpson R Bol ID Bull RP Evershed K Petzke SJ Dockrill 《Rapid communications in mass spectrometry : RCM》1999,13(13):1315-1319
Compound specific stable isotope analyses of managed soils using isotope ratio mass spectrometry have been undertaken as a means of determining early land use practices. delta (15)N amino acid signals demonstrate differences between manured grassland, unmanured grassland and continuous cereal cultivation under long-term experimental land use control conditions, with delta (15)N in hydrophobic amino acids providing the most distinctive signals. Analysis of early modern/medieval and of Bronze age anthropogenic soils from Orkney demonstrates that such signals are retained in archaeological contexts. delta (13)C analyses of n- alkanoic acid components of the fossil, Bronze Age, anthropogenic soils suggest a major terrestrial input to these soils, with uniform composition of formation materials. Surficial soils demonstrate the assimilation of isotopically lighter carbon, providing a means of assessing the mobility of the n- alkanoic acids within soils and sediments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
25.
P Jiménez-Lozano ID Ivanchikova OA Kholdeeva JM Poblet JJ Carbó 《Chemical communications (Cambridge, England)》2012,48(74):9266-9268
Kinetic and DFT studies revealed that protonation of Ti-containing polyoxometalates (Ti-POM) lowers significantly the energy barrier for the heterolytic oxygen transfer from the Ti hydroperoxo intermediate to the alkene, increasing the activity and selectivity of alkene oxidation. 相似文献
26.
A procedure was developed for the synthesis of 2-substituted, including 2-alkenyl-substituted, 4H-anthra[1,2-b]thiopyran-4,7,12-triones and 4H-anthra[2,3-b]thiopyran-4,6,11-triones by cyclocondensation of vic-alkynoylchloroanthraquinones with Na2S.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2205–2209, October, 2004. 相似文献
27.
M. Türky?lmazoglu J.S.B. GajjarRID=""ID="" All correspondence should be addressed to Dr. J.S.B. Gajjar. A.I. Ruban 《Theoretical and Computational Fluid Dynamics》1999,13(2):91-114
RID="ID=" Communicated by P. HallAbstract:The absolute/convective instability of two-dimensional wakes forming behind a flat plate and near the trailing-edge of a thin
wedge-shaped aerofoil in an incompressible/compressible fluid is investigated. The mean velocity profiles are obtained by
solving numerically the classical compressible boundary-layer equations with a negative pressure gradient for the flat plate
case, and the incompressible triple-deck equations for a thin wedge-shaped trailing-edge. In addition for a Joukowski aerofoil
the incompressible mean boundary-layer flow in the vicinity of the trailing-edge is also calculated by solving the interactive
boundary-layer equations. A linear stability analysis of the boundary-layer profiles shows that a pocket of absolute instability
occurs downstream of the trailing-edge with the extent of the instability region increasing with more adverse pressure gradients.
The region of absolute instability persists along the near-wake axis, while the majority of the wake is convectively unstable.
For a thin wedge-shaped trailing-edge in an incompressible fluid, a similar stability analysis of the velocity profiles obtained
via a composite expansion, also shows the occurrence of absolute instability behind the trailing-edge for a wedge angle greater
than a critical value. For increasing values of the wedge angle and for thicker aerofoils, separation takes place near the
trailing-edge and the extent of absolute instability increases. Calculations also show that for insulated plates compressibility
has a stabilizing effect but cooling the wall destabilizes the flow unlike wall heating.}
Received 11 May 1998 and accepted 25 February 1999 相似文献
28.
I. D. Ivanchikova G. É. Usubalieva P. V. Schastnev A. A. Moroz M. S. Shvartsberg 《Russian Chemical Bulletin》1992,41(9):1672-1679
The Cu(I)-catalyzed intramolecular cyclization of 1-phenylethynyl-and 1-hexyn-1-yl-anthraquinone-2-carboxylic acid is a 6-endo-dig-addition, whereas the reaction for 1-(3-phenoxypropyn-1-yl)anthraquinone-2-carboxylic acid proceeds in a directionally nonspecific way. It is shown that the cyclization of vicinal acetylenic derivatives of aromatic carboxylic acids leads to the formation of the more stable of the possible cyclic structures.Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Novosibirsk State University, 630090 Novosibirsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2138–2146, September, 1992. 相似文献
29.
Didier?ArnalEmail authorView authors OrcID profile Olfa?Khlifi 《Algebras and Representation Theory》2018,21(1):219-237
The simple \(GL(n,\mathbb {C})\)-modules are described by using semistandard Young tableaux. Any semistandard skew tableau can be transformed into a well defined semistandard tableau by a combinatorial operation, the Schützenberger jeu de taquin. Associated to the classical Lie groups \(SP(2n,\mathbb {C})\), \(SO(2n+1,\mathbb {C})\), there are other notions of semistandard Young tableaux and jeux de taquin. In this paper, we study these various jeux de taquin, proving that each of them has a simple and explicit formulation as a step-by-step sliding. Any of these jeux de taquin is the restriction of the orthogonal one, associated to \(SO(2n+1,\mathbb {C})\). 相似文献
30.