Novel one-dimensional polyaniline/Ni0.5Zn0.5Fe2O4 hybrid nanostructure: synthesis,magnetic, and electromagnetic wave absorption properties

For the first time, the novel one-dimensional uniform polyaniline (PANI)/Ni_0.5Zn_0.5Fe₂O₄ (NZFO) hybrid nanorods were synthesized by an in situ polymerization approach with the assistance of ultrasound and magnetic field. Owing to the unique shape, structure, and chemical composition, the as-synthesized hybrid nanorods with different PANI/NZFO mass ratios possess adjustable magnetic properties, high-saturated magnetization, and coercivity. In addition, these hybrid nanorods present stronger reflection loss and a wider absorption band than pure NZFO. Especially, the hybrid nanorods containing 59 wt% NZFO exhibit excellent microwave absorption properties, with a maximum reflection loss (R _L) of ?27.5 dB observed at 6.2 GHz. And the widest absorption band (R _L ≤ ?10 dB) is 8.1 GHz, corresponding to a matching thin thickness of 2 mm. It is superior to the previously reported value of PANI/ferrite. Therefore, these PANI/NZFO hybrid nanorods may be candidates for lightweight, low-cost, broadband, and highly efficient microwave-absorbing materials.     

A surface-plasmon-polariton wavelength splitter based on a metal–insulator–metal waveguide

A surface-plasmon-polariton (SPP) wavelength splitter based on a metal–insulator–metal waveguide with multiple teeth is proposed. Using the transfer-matrix method, a plasmonic band gap is identified in the multiple-toothed structure, and the splitting wavelength of the SPP splitter can be easily adapted by adjusting the widths of the teeth and the gaps. The proposed wavelength splitter is further verified through finite-difference time-domain (FDTD) simulations, in which SPPs with incident wavelengths of 756 nm and 892 nm are successfully split and guided in opposite directions in the waveguide, with extinction ratios of 30 dB and 29 dB, respectively.     

Chaotic bat algorithm

Bat algorithm (BA) is a recent metaheuristic optimization algorithm proposed by Yang. In the present study, we have introduced chaos into BA so as to increase its global search mobility for robust global optimization. Detailed studies have been carried out on benchmark problems with different chaotic maps. Here, four different variants of chaotic BA are introduced and thirteen different chaotic maps are utilized for validating each of these four variants. The results show that some variants of chaotic BAs can clearly outperform the standard BA for these benchmarks.     

A fluorescent bicyclic calix[4]arene–oxacyclophane with planar chirality: resolution,chiroptical properties,and absolute configuration

A new inherently chiral calix[4]arene ICC 1 has been disclosed. The dissymmetry of 1 is generated from a chirality plane in the quinol moiety of a 1,3-bridged bicyclic calix[4]arene. ICC 1 has been resolved by enantioselective HPLC, and the chiroptical properties of both isolated antipodes (pS)-1 and (pR)-1 confirm their enantiomeric nature. The absolute configuration of the (pS)-1/(pR)-1 enantiomeric pair was established through time-dependent density functional theory (TDDFT) calculations of electronic circular dichroism (CD) spectra.     

Competing spreading processes and immunization in multiplex networks

Epidemic spreading on physical contact network will naturally introduce the human awareness information diffusion on virtual contact network, and the awareness diffusion will in turn depress the epidemic spreading, thus forming the competing spreading processes of epidemic and awareness in a multiplex networks. In this paper, we study the competing dynamics of epidemic and awareness, both of which follow the SIR process, in a two-layer networks based on microscopic Markov chain approach and numerical simulations. We find that strong capacities of awareness diffusion and self-protection of individuals could lead to a much higher epidemic threshold and a smaller outbreak size. However, the self-awareness of individuals has no obvious effect on the epidemic threshold and outbreak size. In addition, the immunization of the physical contact network under the interplay between of epidemic and awareness spreading is also investigated. The targeted immunization is found performs much better than random immunization, and the awareness diffusion could reduce the immunization threshold for both type of random and targeted immunization significantly.     

Equilibrium strategies for multiple interdictors on a common network

In this work, we introduce multi-interdictor games, which model interactions among multiple interdictors with differing objectives operating on a common network. As a starting point, we focus on shortest path multi-interdictor (SPMI) games, where multiple interdictors try to increase the shortest path lengths of their own adversaries attempting to traverse a common network. We first establish results regarding the existence of equilibria for SPMI games under both discrete and continuous interdiction strategies. To compute such an equilibrium, we present a reformulation of the SPMI game, which leads to a generalized Nash equilibrium problem (GNEP) with non-shared constraints. While such a problem is computationally challenging in general, we show that under continuous interdiction actions, an SPMI game can be formulated as a linear complementarity problem and solved by Lemke’s algorithm. In addition, we present decentralized heuristic algorithms based on best response dynamics for games under both continuous and discrete interdiction strategies. Finally, we establish theoretical lower bounds on the worst-case efficiency loss of equilibria in SPMI games, with such loss caused by the lack of coordination among noncooperative interdictors, and use the decentralized algorithms to numerically study the average-case efficiency loss.     

Profit maximizing coalitions with shared capacities in distribution networks

We study the distribution network structure of multiple firms in the context of demand sensitivity to market offers. The problem consists in determining the profitability of horizontal collaboration between firms in a collaborative distribution schema. It considers the case of a set of regional distribution centers (DCs) where each DC is initially dedicated solely to one firm’s distribution activities and studies when it is beneficial that the DC owners collaborate through sharing their storage-throughput capacity. Such strategic decisions are made in order to improve the distribution capabilities of firms in terms of response time and cost-efficiency compared to the stand-alone situation. The problem is modeled as a coalition formation game in a cooperative framework, and we propose a collaborative distribution game with profit maximization. Three sharing mechanisms are modeled and tested: egalitarian allocation, proportional allocation, and Shapley value. The collaboration decision conditions for a given firm are analytically derived according to the sharing method considered and used to enhance the solution approach. Our numerical results clearly highlight the impact of this innovative collaboration opportunity on the firms’ performance in terms of distribution cost savings and revenue increases. An observed behavior is that the formation of several sub-coalitions prevails over the formation of a grand coalition, and that different cost sharing methods can lead to different sub-coalitions. We also provide managerial insights on the appropriate size of a coalition in various business instances tested, and on the key drivers that foster horizontal collaborative behavior among firms.     

Supply contracting and process innovation in a dynamic supply chain with information asymmetry

We investigate the process innovation and contracting decisions of a dynamic supply chain consisting of a supplier and a manufacturer, with the manufacturer possessing private information about her efficiency of process innovation. To overcome the potential adverse selection problem due to the asymmetric information, the supplier designs a menu of supply contracts that stipulates both the wholesale price and the purchasing quantity. We find that under information asymmetry, the supplier will optimally set a higher wholesale price but a lower purchasing quantity for the manufacturer with high innovation efficiency than that for the manufacturer with low innovation efficiency. As a consequence, the manufacturer with high innovation efficiency will significantly underinvest in innovation due to information asymmetry in addition to the impact of the double marginalization effect. Moreover, although a longer contract period tends to better motivate innovation, it can also magnify the influences of adverse selection on supply chain contracting, leading to a higher wholesale price for the manufacturer with high innovation efficiency.