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Aiming at the protection problem of single link/node in the existing power optical communication network multicast service, a p-cycle protection algorithm is proposed. The protection algorithm firstly uses the optimized prim algorithm to generate a multicast tree, and then generates a p-cycle to protect the entire multicast tree through a heuristic shortest P-cycle construction algorithm, and uses a capacity balancing mechanism in the simulation of the protection algorithm to reduce the blocking rate. The simulation results show that the proposed algorithm's resource redundancy and network blocking rate is lower than the existing Hamiltonian ring protection algorithm. It has practical significance for improving the survivability and stability of optical communication networks.

An efficient surface-enhanced Raman scattering (SERS) substrate has been developed based on Ag-Cu nanoparticle-decorated graphene. The Ag-Cu-graphene (Ag-Cu@G) hybrid structure was prepared by magnetron sputtering for Ag and Cu film and chemical vapor deposition (CVD) for graphene, which avoided defects produced by graphene transferring process. The hybrid materials were confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), and Raman spectroscopy. With R6G as analyst molecule, the enhancement factor (EF) of the order of 106 for Ag-Cu@G sample was obtained. Meanwhile, the substrates had stable enhanced SERS signals after 78-day exposure in air, which could be explained by the fact that the graphene is efficient at maintaining chemical and optical stability. The formation of graphene can contribute a stabilization and fluorescence quenching effect. Moreover, the electromagnetic distribution based on AFM images was simulated by finite difference time domain (FDTD) method.

Despite the wide use of networks as a versatile tool for exploring complex social systems, little is known about how to detect and forecast abrupt changes in social systems. In this report, we develop an early warning approach based on network properties to detect such changes. By analysing three collaborative social networks---one co-stardom, one patent and one scientific collaborative network, we discover that abrupt transitions inherent in these networks can serve as a good early warning signal, indicating, respectively, the dissolution of the Soviet Union, the emergence of the "soft matter" research field, and the merging of two scientific communities. We then develop a clique growth model that explains the universal properties of these real networks and find that they belong to a new universality class, described by the Gumbel distribution.

An ethynylene-linked benzo[1,2-b:4,5-b′]dithiophene-alt-diketopyrrolopyrrole alternating copolymer, EDPP, was designed and synthesized to improve the open-circuit voltage of organic solar cells. The influence of the ethynylene on optoelectronic properties, energy levels, crystallinity, film morphology, and photovoltaic performance was investigated. Optical and electrochemical tests showed that introduction of ethynylene into the polymer backbone resulted in a larger bandgap, deeper HOMO energy level, and enhanced crystallinity due to the planar conformation and electron-withdrawing properties. Grazing incidence wide-angle X-ray scattering (GIWAXS) showed that the pure EDPP film preferentially adopted a face-on orientation with a π–π stacking distance of 3.65 A. After thermal annealing the face-on and edge-on orientations coexisted and the overall degree of crystallinity increased. Blending with PC71BM did not disrupt the crystallinity of the EDPP. Resonant soft X-ray scattering (RSoXS) showed that the EDPP:PC71BM blend films contained large domains, a few hundred nanometers in size. As a result, EDPP:PC71BM photovoltaic devices exhibited a high open-circuit voltage of 0.88 V, but a low short-circuit current, with a moderate power conversion efficiency of 1.98%.

We introduce a notion of random clique evolving network, this network start from a complete subgraph of a -clique, where a is the size of the clique. In every time step T , m nodes are chosen from this network randomly, and forming a new complete subgraph of a -clique. In this way, this network grows in time steps. The numerical investigation shows that the cumulative degree distribution of this network takes an exponential function, which is the property of the homogeneous networks, and the clustering coefficient of this network is larger than that of the ER network. However, the characteristic path length of this network is the similar to that of the ER network, so this network shows the behaviors of small-world networks. Subsequent study shows that this network exhibits hierarchical modular structure for the clustering spectrum vs. k takes power-law. These results are in good agreement with the empirical results on many real-world complex networks, such as urban bus translation network or urban subway network, our model can explain the evolutionary procedure of these spatial networks. Whats more, we present a numerical investigation on the communicability of our model by the Estrada index EE ( G ), the Estrada index EE ( G ) of this network increases with decreasing the rata m / a at the same size N and the same average degree k >. The communicability of the urban public translation networks is very important, our results have a certain guiding significance for the construction of urban bus translation network and urban subway network.

Traditional detection techniques are affected by surrounding factors and cannot accurately determine the location of the fault point. In order to solve the problem, a short-term flashover fault intelligent detection method in the paper is proposed for high-power main network power system. The short-term flashover fault feature of the high-power main network power system is extracted by the wavelet-type wavelet packet energy moment. The CPRS networking mode is used to intelligently detect the short-term flashover fault of the high-power main network power system. Experiments show that the proposed technique is more accurate than traditional detection techniques.