Rational designing of one-dimensional (1D) magnetic alloy to facilitate electromagnetic (EM) wave attenuation capability in low-frequency (2–6 GHz) microwave absorption field is highly desired but remains a significant challenge. In this study, a composite EM wave absorber made of a FeCoNi medium-entropy alloy embedded in a 1D carbon matrix framework is rationally designed through an improved electrospinning method. The 1D-shaped FeCoNi alloy embedded composite demonstrates the high-density and continuous magnetic network using off-axis electronic holography technique, indicating the excellent magnetic loss ability under an external EM field. Then, the in-depth analysis shows that many factors, including 1D anisotropy and intrinsic physical features of the magnetic medium-entropy alloy, primarily contribute to the enhanced EM wave absorption performance. Therefore, the fabricated EM wave absorber shows an increasing effective absorption band of 1.3 GHz in the low-frequency electromagnetic field at an ultrathin thickness of 2 mm. Thus, this study opens up a new method for the design and preparation of high-performance 1D magnetic EM absorbers.

Despite significant progress in the theory of evolutionary algorithms, the theoretical understanding of true population-based evolutionary algorithms remains challenging and only few rigorous results exist. Already for the most basic problem, the determination of the asymptotic runtime of the (µ + λ) evolutionary algorithm on the simple OneMax benchmark function, only the special cases µ = 1 and λ = 1 have been solved.In this work, we analyze this long-standing problem and show the asymptotically tight result that the runtime T , the number of iterations until the optimum is found, satisfieswhere log + x := max{1, log x} for all x > 0. The same methods allow to improve the previous-best O( n log n λ + n log λ) runtime guarantee for the (λ+λ) EA with fair parent selection to a tight Θ( n log n λ + n) runtime result. * A preliminary version of this work [ADFH18] was presented at the Genetic and Evolutionary Computation Conference (GECCO) 2018. In this version, the presentation was improved by rewriting almost the entire text, by giving a clearer comparison with the previous state of the art, by making many proofs more rigorous, by extending the lower bounds to arbitrary fitness functions (subject to a mild restriction on the number of global optima), and by extending our results to the so-called (N + N ) EA using a fair parent selection.

The advancement of electromagnetic (EM) protection technology promotes the urgent demand for the structural design of electromagnetic functional materials. Here, tadpole‐like Fe@SiO2@C‐Ni (FSCN) composites with magnetic core–shell and nonspherical hollow architectures through multiple hydrolysis‐polymerization reactions are reported. The Fe core and well‐distributed Ni nanoparticles greatly promote the magnetic properties of FSCN and construct a multiscale magnetic coupling network. Meanwhile, the multishell composites consisting of carbon shell with Ni decorated possess an abundance of heterogeneous interfaces, generating effective interfacial polarization and relaxation. The hollow feature and the coordination of magnetic and dielectric capacities offer an optimized impedance balance, providing a fundament for the microwaves propagating into the absorber. Owing to the attractive effects resulted from the deliberate tadpole‐like structure design, the FSCN composites ensure an effective EM energy conversion at the high‐frequency region, which obtain the strongest reflection loss value of −45.2 dB and the extremely broad effective absorption bandwidth of 13.1 GHz. This work provides an important solution for magnetic‐dielectric nanostructure design for microwave absorption and energy conversion materials.

Assembling of multiple-component composites into a beneficial multi-shell structure have been demonstrated as an efficiently strategy to induce wideband electromagnetic (EM)-attenuation in principle. However, structural engineering with selectively component remains...

Structural engineering via the template method is efficient for micro‐nano assembling. However, only structural design and lack of composition control restrict their advanced application. To overcome this issue, applying a template to simultaneously realize the structural design and fine component control is highly desired, which has been ignored. In this study, a spinel‐shaped MoS2 heterostructure with controlled phase ratios of 1H and 2H phase is developed using the AlOOH template method. This work demonstrates that the MoS2 phase transition mechanism from 2H to 1T is substantially attributed to the close exposed crystal's surface and approximately accordant surface energy. The superiority and additional proof are provided based on density‐functional theory simulation, transmission electron microscope holography, etc. With an effective absorptance region of 6.3 GHz under a thickness of 1.4 mm, the reported samples present outstanding microwave absorption capacity. This is attributed to the beneficial coupled effect between the well‐designed structure and phase regulation. This work offers valuable insights into structural engineering and component regulation template methods.