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Enhancing the robustness of complex networks is of great practical significance as it ensures the stable operation of infrastructure systems. We measure its robustness by examining the size of the largest connected component of the network after initial attacks. However, traditional research on network robustness enhancement has mainly focused on low-order networks, with little attention given to higher-order networks, particularly higher-low order coupling networks(the largest connected component of the network must exist in both higher-order and low-order networks). To address this issue, this paper proposes robust optimization methods for higher-low order coupled networks based on the greedy algorithm and the simulated annealing algorithm. By comparison, we found that the simulated annealing algorithm performs better. The proposed method optimizes the topology of the low-order network and the higher-order network by randomly reconnecting the edges, thereby enhancing the robustness of the higher-order and low-order coupled network. The experiments were conducted on multiple real networks to evaluate the change in the robustness coefficient before and after network optimization. The results demonstrate that the proposed method can effectively improve the robustness of both low-order and higher-order networks, ultimately enhancing the robustness of higher-low order coupled networks.
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Algoritmos , Modelos TeóricosRESUMEN
Nowadays, the exploration of electromagnetic (EM) wave absorbers with anticorrosion to improve the survivability and environmental adaptability of military targets in the harsh environments is becoming an attractive and unavoidable challenge. Herein, through modulation of the metal composition in the precursors, the core@shell structure Prussian blue analog-derived NiCo@C, CoFe@C, NiFe@C, and NiCoFe@C are obtained with excellent EM wave absorption performance. As for NiCoFe@C, ascribed to the coupling effect of the dual magnetic alloy, a minimum reflection loss (RL) of -47.6 dB and an effective absorption bandwidthof 5.83 GHz are realized, which cover the whole Ku-band. Meanwhile, four absorbers display the lower corrosion current density (10-4 -10-6 A cm-2 ) and larger polarization resistance (104 -106 Ω) under acid, neutral, and alkaline corrosion conditions over uninterrupted 30 days. Furthermore, due to the spatial barrier effect and the passivation effect of the graphitic carbon shell , the continuous salt spray test has little effect on RL performance and inconspicuously changes the surface morphologies of coating, demonstrating its excellent bifunctional performance. This work lays the foundation for the development of metal-organic frameworks-derived materials with both anticorrosion and EM wave absorption performance.
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Relationship between nighttime snack and human health conditions remains unclear. In this paper, we analyzed the association of frequency of nighttime snacking with obesity, hyperlipidemia and hyperglycemia using a Chinese teacher cohort. The Chinese teacher study contains 22,176 of the general adult population operated on in 2015. Information of nighttime snacking frequency was acquired by questionnaire. Overweight and obesity outcome were assessed by body mass index (BMI), and hypertension; hyperlipidemia and hyperglycemia were self-reported. Associations between nighttime snacking consumption and outcomes were performed with multivariat regression and further stratification analyses. We found a significant association (OR 2.11, 95% CI 1.24, 3.62;P for trend<0.001) between most frequent nighttime snacking and hyperglycemia. A remarkable association was also observed between most frequent consumption of nighttime snack and obesity (OR 3.10, 95% CI 1.63, 5.89; Pfor trend<0.001). The present results provide epidemiological evidence that consumption of nighttime snack was associated with obesity and hyperglycemia in Chinese adult teachers. However, the underlying mechanisms still need further investigation..