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In this article, the multisynchronization issue of coupled memristive neural networks (CMNNs) with unbounded time delays is investigated. To begin with, a class of generalized Gaussian-wavelet-type activation functions is adopted to extend the number of stable equilibrium states. On this basis, a distributed impulsive controller is constructed to realize the multiple synchronization of the delayed CMNNs. Under the concepts of $\mu $ -stability, Filippov solution, and differential inclusion, some sufficient conditions are derived such that the addressed system can possess $(2r + 1)^{n}\,\,\mu $ -stable synchronization manifolds. The convergence performance of solutions is determined by the time delays. As the time delays increase, the stability of synchronization manifolds will transform from exponential stability to power-stability, log-stability, or log–log-stability as special cases. Moreover, considering the modeling error and external disturbance, we further investigated the multisynchronization of delayed CMNNs with parametric uncertainties and stochastic perturbations, and some robust multisynchronization criteria are obtained. Finally, the effectiveness of the obtained results is verified by numerical simulations. [ABSTRACT FROM AUTHOR]

Reef carbonates represent a practical option for continuous sampling in seawater 87Sr/86Sr values studies. A study of Sr isotopes is carried out for reef carbonates from the well "Xike‐1", Shi Island, Xisha Islands, with the purpose of reconstructing the changing process of seawater 87Sr/86Sr values since the Neogene in the South China Sea (SCS). The results provide insights into the impact of paleoclimatic and paleoenvironmental factors on the seawater 87Sr/86Sr values in the SCS. Our study indicates that the 87Sr/86Sr values in reef carbonates have increased since the Neogene. Those variation process can be divided into three stages, which are the fluctuant rising stage (Early Miocene to Middle Miocene), the steady rising stage (Middle Miocene to Late Miocene), and the fluctuating stage (Pliocene to Quaternary), respectively. The change of terrigenous influx is the main factor controlling seawater 87Sr/86Sr values in the SCS. The 87Sr/86Sr values in reef carbonates are slightly higher than that in the coeval seawater, which reflects a semiclosed environment of the SCS relative to the open ocean. The variations of seawater 87Sr/86Sr values and terrigenous influx in the SCS have no obvious correspondence with the changes of seawater δ18O values recorded by the benthonic foraminiferal skeletons in the drilling core of ODP site 1148. Thus, paleoclimatic factor is unlikely to be the dominant factor for the changes of terrigenous influx in the study area. However, there is a good correspondence between the variation rates of the 87Sr/86Sr values, the accumulation rates of terrigenous materials, and the uplifting rates of the Qinghai‐Tibet Plateau. This indicates that the changes of terrigenous influx should be caused by enhancement of erosion, weathering, or transportation linked to the tectonic activities. The uplift of the Qinghai‐Tibet Plateau and the variations of uplifting rates should be the main factor controlling the variations of the terrigenous influx in the SCS, which would further influence the seawater 87Sr/86Sr values. [ABSTRACT FROM AUTHOR]

Mg isotope composition (δ26Mg) of seawater may serve as a tool for reconstructingthe global Mg cycle over geologic time scales. Marine carbonate sediments havebeen proposed as a potential archive for seawater δ26Mg values. However, the Mgisotope composition of seawater in the Cenozoic has remained controversial. Here wereport our investigation on the Mg isotope compositions of reef carbonates from thewell "Xike-1" reef core in the Xisha Islands, South China Sea. Magnesium isotopeanalysis was complemented by analyses of Sr-C-O isotopic compositions, majorand trace element concentrations, and mineral compositions. The δ26Mg values inlimestones from the well "Xike-1" reef core range from -5.03‰ to -3.60‰ andthe δ26Mg values in dolostones range from -2.98‰ to -2.72‰Ṁultiple lines ofevidence consistently indicated that biological vital effects are likely the main factorcontrolling the variations of δ26Mg values in limestones, which results in a lagerMg isotopic variation and a lighter δ26Mg value in the limestones. Mg isotopiccompositions of the dolostones from the well "Xike-1" reef core are conservative duringdiagenesis, which is the effective archive of seawater δ26Mg values. The seawaterδ26Mg values are basically invariant during the past 21 Myr. The fractionationfactor of Mg isotope between dolomite and fluids associated with dolomitizationranging from -2.26‰ to -2.02‰Ṁoreover, the Mg isotopic fractionation betweencalcite and fluids should range from -4.20‰ to -2.77‰İn this article, it is likelythat the ocean is at steady state with respect to seawater Mg isotopic compositionin the past 21 Myr. The mass balance calculation of Mg isotopes implies that theMg flux of dolomitization output is about 0.63-0.79 Tmol/yr in the modern ocean,which accounts for about 12%-13% of the Mg flux of riverine input to the ocean. [ABSTRACT FROM AUTHOR]

To facilitate penetrating-imaging oriented applications such as nondestructive internal defect detection and localization under obstructed environment, a novel pixel-level information fusion strategy for mmWave and visible images is proposed. More concretely, inspired by both the advancement of deep learning on universal image fusion and the maturity of near-field millimeter wave imaging technology, an effective deep transfer learning strategy is presented to capture the information hidden in visible and millimeter wave images. Furthermore, by implementing fine-tuning strategy and by using an improved bilateral filter, the proposed fusion strategy can robustly exploit the information in both the near-field millimeter wave field and the visual light field. Extensive experiments imply that the proposed strategy can provide superior performance in terms of accuracy and robustness under real-world environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)