Analytical controllability of deterministic scale-free networks and Cayley trees

According to the exact controllability theory, the controllability is investigated analytically for two typical types of self-similar bipartite networks, i.e., the classic deterministic scale-free networks and Cayley trees. Due to their self-similarity, the analytical results of the exact controllability are obtained, and the minimum sets of driver nodes (drivers) are also identified by elementary transformations on adjacency matrices. For these two types of undirected networks, no matter their links are unweighted or (nonzero) weighted, the controllability of networks and the configuration of drivers remain the same, showing a robustness to the link weights. These results have implications for the control of real networked systems with self-similarity.Comment: 7 pages, 4 figures, 1 table; revised manuscript; added discussion about the general case of DSFN; added 3 reference

Causal Relationship among the National Wealth, the Consumption and Shanghai Composite Index

Based on data between the December 1990 to July 2009 of the industrial added value, retail sales and the Shanghai composite index, Cointegration and Granger Causality test have been done and found that: a) An stable cointegration relationship exists among the industrial added value, retail sales and Shanghai composite index, and they are positively correlated. b) The total industrial added value and retail sales Granger cause the Shanghai composite index, but the reverse affect did not observed, which explain China's stock market is not yet a mature market. c) Compared to the total retail sales, the impact of industrial added value on the Shanghai composite index delayed a little longer.Keywords: cointegration test; Granger causality test; industrial added value; total retail sales; the Shanghai Composite Inde

Dimensional crossover of thermal conductance in graphene nanoribbons: A first-principles approach

First-principles density-functional calculations are performed to investigate the thermal transport properties in graphene nanoribbons (GNRs). The dimensional crossover of thermal conductance from one to two dimensions (2D) is clearly demonstrated with increasing ribbon width. The thermal conductance of GNRs in a few nanometer width already exhibits an approximate low-temperature dependence of $T^{1.5}$, like that of 2D graphene sheet which is attributed to the quadratic nature of dispersion relation for the out-of-plane acoustic phonon modes. Using a zone-folding method, we heuristically derive the dimensional crossover of thermal conductance with the increase of ribbon width. Combining our calculations with the experimental phonon mean-free path, some typical values of thermal conductivity at room temperature are estimated for GNRs and for 2D graphene sheet, respectively. Our findings clarify the issue of low-temperature dependence of thermal transport in GNRs and suggest a calibration range of thermal conductivity for experimental measurements in graphene-based materials.Comment: 18 pages, 4 figure

Global and partitioned reconstructions of undirected complex networks

It is a significant challenge to predict the network topology from a small amount of dynamical observations. Different from the usual framework of the node-based reconstruction, two optimization approaches (i.e., the global and partitioned reconstructions) are proposed to infer the structure of undirected networks from dynamics. These approaches are applied to evolutionary games occurring on both homogeneous and heterogeneous networks via compressed sensing, which can more efficiently achieve higher reconstruction accuracy with relatively small amounts of data. Our approaches provide different perspectives on effectively reconstructing complex networks.Comment: 6 pages, 2 figures, 1 table; revised version; added numerical results of the PR in Table 1 and expanded Section 4; added 7 reference

2,4-Dichloro-7-fluoro­quinazoline

The mol­ecule of the title compound, C8H3Cl2FN2, is essentially planar, with a maximum deviation of 0.018 (2) Å. In the crystal, π–π stacking is observed between parallel quinazoline moieties of adjacent mol­ecules, the centroid–centroid distance being 3.8476 (14) Å