Multiferroic composites are of particular interest because of their high magnetoelectric (ME) coupling at room temperature. In multiferroic composites, ME coupling is a strain mediated effect achieved via the interfaces between the magnetic and electrical subsystems through elastic deformation. In this paper, ME coupling of laminate composites is investigated under combined magnetic and mechanical loadings. Three types of laminate composites are used, with piezoelectric phase layers of PZT plates and the magnetic phase layers comprising Terfenol-D, Ni and Metglas, respectively. As the applied compressive stress increases, the ME coefficient (α ME ) decreases monotonically for Terfenol-D/PZT/Terfenol-D and Metglas/PZT/Metglas, while it slightly increases for Ni/PZT/Ni laminate. To reveal the influence of the magnetic layers on the ME coupling, measurements of magnetostriction under combined magnetic and compressive loadings are carried out for Terfenol-D, Ni and Metglas. Based on the equivalent circuit model, the peak values of the ME coefficient for different compressive stresses are predicted for the laminate composites; these agree well with the experimental data. It is suggested that the compressive stress-induced strain, as well as the magnetostrictive response of the magnetic material, mainly contribute to the mechanical-magnetic-electrical coupling behavior of the multiferroic composites.

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The development of the online to offline business has accelerated the growth of the online food ordering market in China. The widespread use of disposable takeaway containers has resulted in a large amount of waste, which seriously affects the ecological environment. This paper studied the collection modes of reusable takeaway containers and the preferences of consumers and merchants. First, after two rounds of discussion and revision, four takeaway container collection modes were designed. Second, based on the survey results of consumers and merchants, a binary logistic regression model was applied to analyze the preferences of consumers and merchants. The results showed that the consumers’ delivery requirements and the current disposal of takeaway containers had a significant impact on consumers’ preferences. Consumers were more concerned about the hygienic status of the containers, food health and safety, while the merchants were more concerned about the increased costs. The promotion of collection modes requires the special consideration of the locations of dishwashing facilities and increased costs. Finally, according to the preferences and concerns of consumers and merchants, several suggestions on promoting the collection mode, such as the use of different promotion strategies for different people, the short distance of dishwashing facilities, reward systems, and food safeguard measures were proposed. This research provides guidance for decision making regarding the sustainable consumption and the promotion of reusable takeaway containers, which will contribute to resource conservation, ecological environmental improvement and sustainability.

In this study, a self-biased magnetoelectric (ME) composite is designed without employing the epoxy and magnetization-graded materials. The composite is referred to as the three-phases-embedded one, consisting of a PZT ring with an inner disc of Ni50Fe50 and an outer ring of Ni via hard contact (Ni/PZT/FeNi composite). A large self-biased ME response and apparent hysteresis behavior are observed in the composites. Stress analysis and finite element simulation are carried out to reveal the underlying mechanism of the self-biased ME coupling and the magnetic-elastic-electric coupling of the embedded composites. The results indicate that the assembly stress induces magnetization of Ni at zero bias, and renders the self-biased ME coupling effect for the embedded Ni/PZT/FeNi composite.

In situ observations of ferroelectric domain structure evolution, and magnetoelectric (ME) coupling are investigated for PMN‐28PT/Terfenol‐D (abbreviation of Pb(Mg1/3Nb2/3)O3‐28PbTiO3/Tb0.3Dy0.7Fe2) and PMN‐33PT/Terfenol‐D composites under the magnetic loadings. The composite of PMN‐33PT/Terfenol‐D shows stronger ME coupling than that in PMN‐28PT/Terfenol‐D. At a thickness of 0.10–0.12 mm for the single crystal plate, a giant magnetoelectric coefficient (αME) up to 2 V/cm·Oe is obtained for PMN‐33PT/Terfenol‐D at a static magnetic field of 200 Oe and 1 kHz of the alternating magnetic field. In situ domain structure observations reveal the domain morphology change during the applied magnetic loadings. In PMN‐28PT, the domains are of predominantly rhombohedral (R) phase and they change into monoclinic MA phase upon the magnetic loading via the strain transferred between Terfenol‐D plate and PMN‐PT single crystal. In PMN‐33PT, domains of orthorhombic (O), R, and monoclinic MC coexist and phase transitions from O to MC and further to R phase occur upon the magnetic loading. The undulation and diversity of the domain structure makes the domains more susceptible to the magnetic loading via strain transferred between Terfenol‐D plate and PMN‐PT single crystal, and consequently, a strong ME coupling in the composites.