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With the advancement of radar technology toward multifunctionality and cognitive capabilities, traditional radar countermeasures are no longer sufficient to meet the demands of countering the advanced multifunctional radar (MFR) systems. Rapid and accurate generation of the optimal jamming strategy is one of the key technologies for efficiently completing radar countermeasures. To enhance the efficiency and accuracy of jamming policy generation, an efficient jamming policy generation method based on multi-timescale ensemble Q-learning (MTEQL) is proposed in this paper. First, the task of generating jamming strategies is framed as a Markov decision process (MDP) by constructing a countermeasure scenario between the jammer and radar, while analyzing the principle radar operation mode transitions. Then, multiple structure-dependent Markov environments are created based on the real-world adversarial interactions between jammers and radars. Q-learning algorithms are executed concurrently in these environments, and their results are merged through an adaptive weighting mechanism that utilizes the Jensen–Shannon divergence (JSD). Ultimately, a low-complexity and near-optimal jamming policy is derived. Simulation results indicate that the proposed method has superior jamming policy generation performance compared with the Q-learning algorithm, in terms of the short jamming decision-making time and low average strategy error rate. [ABSTRACT FROM AUTHOR]

In the last few decades, tear-based biosensors for continuous glucose monitoring (CGM) have provided new avenues for the diagnosis of diabetes. The tear CGMs constructed from nanomaterials have been extensively demonstrated by various research activities in this field and are gradually witnessing their most prosperous period. A timely and comprehensive review of the development of tear CGMs in a compartmentalized manner from a nanomaterials perspective would greatly broaden this area of research. However, to our knowledge, there is a lack of specialized reviews and comprehensive cohesive reports in this area. First, this paper describes the principles and development of electrochemical glucose sensors. Then, a comprehensive summary of various advanced nanomaterials recently reported for potential applications and construction strategies in tear CGMs is presented in a compartmentalized manner, focusing on sensing properties. Finally, the challenges, strategies, and perspectives used to design tear CGM materials are emphasized, providing valuable insights and guidance for the construction of tear CGMs from nanomaterials in the future. [ABSTRACT FROM AUTHOR]

Designing artificial nano-enzymes for scavenging reactive oxygen species (ROS) in chondrocytes (CHOs) is considered the most feasible pathway for the treatment of osteoarthritis (OA). However, the accumulation of ROS due to the amount of nano-enzymatic catalytic site exposure and insufficient oxygen supply seriously threatens the clinical application of this therapy. Although metal–organic framework (MOF) immobilization of artificial nano-enzymes to enhance active site exposure has been extensively studied, artificial nano-enzymes/MOFs for ROS scavenging in OA treatment are still lacking. In this study, a biocompatible lubricating hydrogel-loaded iron-doped zeolitic imidazolate framework-8 (Fe/ZIF-8/Gel) centrase was engineered to scavenge endogenous overexpressed ROS synergistically generating dissolved oxygen and enhancing sustained lubrication for CHOs as a ternary artificial nano-enzyme. This property enabled the nano-enzymatic hydrogels to mitigate OA hypoxia and inhibit oxidative stress damage successfully. Ternary strategy-based therapies show excellent cartilage repair in vivo. The experimental results suggest that nano-enzyme-enhanced lubricating hydrogels are a potentially effective OA treatment and a novel strategy. [ABSTRACT FROM AUTHOR]

Biotic exchanges between Taiwan and Mainland China have shaped the biodiversity and ecosystems of both regions. Exchanges from Mainland China to Taiwan have received more attention, mainly studied in terrestrial vertebrates, while the reverse direction and invertebrates have largely been overlooked. Here, we explore the dispersal events between these two regions based on the moths of three species groups of Obeidia, including Taiwan taxa and its relatives from mainland. We conducted mixed methods and analysis, including reconstructing a phylogenetic tree, estimating associated divergence times and inferring ancestral areas and source regions, to explore the phylogeographical structure and genetic pattern of three groups based on eight genes. Our results revealed a structure of three clades and every clade included at least one Taiwanese taxa and its closest relatives of mainland of China, and also served Taiwan as an important source region of two mainland taxa. Our study revealed various origin pattern and dispersal models on the basis of three species groups of Obeidia. Bi‐directional biotic exchange via a land bridge were found: four Taiwanese taxa originated from mainland, and two of them migrated back to mainland. Both eastern Himalayas and south China are important origin areas for Taiwan biota, and the dominant source region may need multiple insect cases to confirm. Our study also provided evidences for disjunct distribution from the perspective of insecta molecular phylogeny. [ABSTRACT FROM AUTHOR]

In repaired marine concrete structures, generally, an interface exists between old and new concrete, however, the influence of this interface on durability has yet not been well understood. In this study 18 reinforced concrete beams with new‐to‐old concrete interfaces (N–O interfaces) were designed to investigate chloride transport through a cracked interface. The effects of crack widths at the interface, concrete strain, and the chloride exposure time were considered, respectively. Results showed that the N–O interfaces having crack widths between 0 and 0.13 mm posed no significant impact on the chloride transport in the depth direction of the N–O interfaces, however when the crack width exceeded 0.13 mm, the chloride concentration gradually increased as the crack width increased. Chloride transport through the horizontal direction of the N–O interface was different between new and old concrete matrix when the crack width reached 0.18–0.20 mm. The surface layer with a range of 5–10 mm depth of concrete was sensitive to the variation of concrete strain, and the evolution of chloride concentration with concrete strain presented a logarithm relationship. Within the exposure period between 60 and 90 days, the increasing rate of chloride concentration was higher than that between 30 and 60 days. The study can provide some recommendations for repair of concrete elements exposed to a chloride‐laden exposure environment. [ABSTRACT FROM AUTHOR]

A facile one-step solvothermal method was developed to synthesize Ir-doped Co-based metal–organic framework (CoIr-MOF) nanoarrays as a bifunctional electrocatalyst for water–glucose co-electrolysis. It was demonstrated that in situ incorporation of a low-content of Ir cations could modulate the electronic structure of Co active centers and thus boost the electrocatalytic performance towards both the hydrogen evolution reaction and glucose-to-formate oxidation reaction. [ABSTRACT FROM AUTHOR]

In bistatic spaceborne High-Resolution Wide-Swath SAR systems (HRWS-SAR), the azimuth reconstruction to obtain a uniform sampling signal or Doppler spectrum is a crucial step in image processing because azimuth signals are generally of non-uniform sampling type. In this study, the variant transmitting distance to receiving distance radio is approximated to be a constant, the equivalence between the bistatic and monostatic SAR azimuth interchannel transfer functions is deduced, and the azimuth signal model in spaceborne HRWS-SAR with general bistatic configuration is established. Furthermore, the matrix inversion algorithm to reconstruct the azimuth signal is proposed; in addition, to measure the reconstruction performance, the formulae for the signal noise ratio scaling factor and the azimuth ambiguity signal ratio are provided. The azimuth reconstruction is simulated in several spaceborne HRWS-SAR systems with typical bistatic configuration, and the results show that the azimuth Doppler spectrum can be correctly reconstructed via the matrix inversion algorithm when the azimuth sampling is conducted without coinciding samples.

Rational construction of advanced electrocatalysts that can realize coupling of the hydrogen evolution reaction (HER) with electrooxidation of organic compounds, rather than the sluggish oxygen evolution reaction, will make the catalytic efficiency of electrolytic hydrogen production more efficient. Herein, we report a bifunctional chainmail catalyst composed of NiGd nanoparticles wrapped by N-doped graphene shells (NiGd@N–C) for both the HER and methanol oxidation reaction (MOR). Benefiting from the unique architecture, the NiGd@N–C catalyst exhibits excellent HER activity under alkaline conditions (η10 = 45 mV), and also performed with high activity for selective methanol oxidation to formate. Theoretical analysis verifies that introducing the rare earth Gd element could enhance electron penetration from the NiGd core to the N–C shell, which was responsible for enhanced HER and MOR performance. Impressively, the methanol–water co-electrolysis system based on bifunctional NiGd@N–C catalysts only needs 1.34 V of cell voltage to reach 10 mA cm−2 for co-electrosynthesis of hydrogen and formate. [ABSTRACT FROM AUTHOR]

This paper proposes a novel transmit waveform design method of multiple input multiple output (MIMO) dual functional radar communication (DFRC) system based on an optimal constellation, which takes into account the waveform diversity advantages of MIMO radar in view of the competition between electronic information devices for spatial spectrum resource. Firstly, we constructed an optimization design model for the transmit waveform of the MIMO-DFRC system is constructed. Secondly, the communication information embedding strategy is designed based on the joint constraint of communication signal of amplitude and phase. Simultaneously, the constellation of the expected communication signal to further reduce the bit error rate (BER) of communication information transmission is optimized, which efficiently solved the BER by utilizing the sequential linear programming algorithm based on the first-order Taylor expansion (SLP-FTE). As the designed waveform can achieve the integrated functions of radar target detection and communication information transmission simultaneously, it can effectively solve the problem of spectrum congestion. Finally, the simulation analysis verifies the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Rationally designing advanced electrocatalysts and innovative energy-efficient electrolysis systems for converting carbon dioxide (CO2) into value-added chemicals or fuels is of significance yet challenging. As for the electrochemical CO2 reduction reaction (CO2RR), the electrocatalytic efficiency is largely limited by the CO2 adsorption and activation capability of active sites. Herein, B-doped Bi nanosheet arrays grown on Cu foam are synthesized by a galvanic replacement combined with in situ doping strategy. It was demonstrated that the B dopant could serve as Lewis acid sites for promoting the adsorption of CO2, and more importantly, regulate the electronic structure and crystallinity of Bi nanosheet arrays, and create abundant amorphous/crystalline two-phase interfaces, which boost the CO2RR activity. Moreover, coupling the CO2RR with the thermodynamically more favorable methanol oxidation reaction (replacing the kinetically sluggish oxygen evolution reaction) within a pH-asymmetric electrolysis system could realize highly efficient pair-electrosynthesis of formate with a much-reduced energy consumption compared with a conventional electrochemical CO2RR system. [ABSTRACT FROM AUTHOR]