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We introduce a simple algorithm that constructs scale-free random graphs efficiently: each vertexi has a prescribed weight Pi ∝ i-μ (0 < μ< 1) and an edge can connect verticesi andj with rateP
i
P
j
. Corresponding equilibrium ensemble is identified and the problem is solved by theq → 1 limit of the q-state Potts model with inhomogeneous interactions for all pairs of spins. The number of loops as well
as the giant cluster size and the mean cluster size are obtained in the thermodynamic limit as a function of the edge density.
Various critical exponents associated with the percolation transition are also obtained together with finite-size scaling
forms. The process of forming the giant cluster is qualitatively different between the cases of λ > 3 and 2 < λ < 3, whereλ
= 1 +μ
-1
is the degree distribution exponent. While for the former, the giant cluster forms abruptly at the percolation transition,
for the latter, however, the formation of the giant cluster is gradual and the mean cluster size for finiteN shows double peaks. 相似文献
2.
GuangYaXIANG HeinerECKSTEIN 《中国化学快报》2004,15(7):768-770
The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt is reported. It was synthesized by coupling Phac-Met-OEt with Gly-OMe. HCI, Trp-OMe and Met-OEt successively, catalyzed by α-chymotrypsin, papain and α-chymotrypsin respectively. The results of FAB-MS showed that the products had the correct molecular mass. 相似文献
3.
Wen Han LIN* Jun LI Hong Zheng FU Peter PROKSCH National Research Laboratories of Natural Biomimetic Drugs Peking University Beijing Institut fuer Pharmazeutische Biologie Heinrich-Heine Universitat Duesseldorf D- 《中国化学快报》2001,(5)
In the previous report on bioactive secondary metabolites from the sponge-associated fungus Aspergillus versicolor (Vuill) Tirab, the bioassay guiding fractionation led to isolation of six new compounds with unusual skeleton based on chromone ring system from the inculated fungus which was isolated from fresh samples of marine sponge Xestospongia exigua, collected along coast line of Bali, Indonesia in 19971. In the continuation of our chemical investigation on the marine fungus, four compou… 相似文献
4.
Novel Chromone Derivatives from Marine Fungus Aspergillus versicolor Isolated from the Sponge Xestospongia exigua 总被引:2,自引:0,他引:2
Wen Han LIN* Hong Zheng FU Jun LI Peter Proksch National Research Laboratories of Natural Biomimetic Drugs Peking University Beijing Institut fuer Pharmazeutwasche Biologie Heinrich-Heine Universitat Duesseldorf D- 《中国化学快报》2001,(3)
In the continuation of our research for the bioactive secondary metabolites from the sponge-associated fungi, the bioassay guiding fractionation led to the isolation of six new secondary metabolites with unusual skeleton based on chromone ring system from the inoculated fungus Aspergillus versicolor, that had been isolated from fresh samples of marine sponge Xestospongia exigua, collected along coast line of Bali, Indonesia in 1997. The basic skeleton of those compounds possessed an oxohexacy… 相似文献
5.
Thomas PETERNELL Mathematisches Institut Universitt Bayreuth D- Bayreuth Germany 《中国科学A辑(英文版)》2008,(4)
In this paper we study finite morphisms of projective and compact K■hler manifolds, in particular,positivity properties of the associated vector bundle,deformation theory and ramified endomorphisms. 相似文献
6.
We consider an Adaptive Edge Finite Element Method (AEFEM) for the 3D eddy currents equations with variable coefficients using a residual-type a posteriori error estimator. Both the components of the estimator and certain oscillation terms, due to the occurrence of the variable coefficients, have to be controlled properly within the adaptive loop which is taken care of by appropriate bulk criteria. Convergence of the AEFEM in terms of reductions of the energy norm of the discretization error and of the oscillations is shown. Numerical results are given to illustrate the performance of the AEFEM. 相似文献
7.
SYNTHESIS AND CHARACTERIZATION OF PHENOTHIAZINE-BASED PPV-TYPE COPOLYMERS CONTAINING FLUORENE AND THIOPHENE MOIETIES 总被引:1,自引:0,他引:1
WANG Chen LU Yan LIU Song YANG Liying YIN Shougen Silvia Janietz Hartmut Krueger Armin Wedel HUA Yulin Institute of Material Physics Tianjin University of Technology Tianjin China Fraunhofer Institute of Applied Polymer Research Geiselbergstrasse D- Golm Germany 《Chinese Journal of Reactive Polymers》2005,(Z1)
1. INTRODUCTION Since the first report of efficient polymer light emitting diode (PLED) in 1990, conjugated polymers have intrigued great interests because of substantial promise for electro-optical applications [1,2]. It is essential to develop novel str… 相似文献
8.
A new compound, named (S)-α-acetylamino-β-(3-indole)propano1 (1) was isolated, along with two known compounds teleocidin B 1 and emycin B from culture broth of a streptomycete strain YIM33176 (streptomyces pleomorphus). The structure of 1 was determined by detailed spectroscopic investigation. 相似文献
9.
Eberhard Schmidt 《中国颗粒学报》2009,(1)
Particle layers tend to build up on walls in many filtration and separation processes, calling for periodic removal in order to keep the apparatus running. Important factors are the adhesion of the layer on the substrate and the cohesion of the particles in the layer. Models describing such layer detachment generally assume constant and homogeneous conditions for the forces acting on the layer. But in reality detachment is extremely non-stationary concerning place and time, primarily due to changing conditi... 相似文献
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