Search

This paper is concerned with nonzero-sum discrete-time stochastic games in Borel state and action spaces under the expected discounted payoff criterion. The payoff function can be unbounded. The transition probability is a convex combination of finite probability measures that are dominated by a probability measure on the state space and depend on the state variable. Under suitable conditions, the authors establish the existence of stationary almost Markov ε-equilibria and give an approximation method via some stochastic games with bounded payoffs. Finally, a production game is introduced to illustrate the applications of the main result, which generalizes the bounded payoff case.

In this paper, we investigate a blow-up phenomenon for a semilinear parabolic system on locally finite graphs. Under some appropriate assumptions on the curvature condition CDE’(n,0), the polynomial volume growth of degree m, the initial values, and the exponents in absorption terms, we prove that every non-negative solution of the semilinear parabolic system blows up in a finite time. Our current work extends the results achieved by Lin and Wu (Calc Var Partial Differ Equ, 2017, 56: Art 102) and Wu (Rev R Acad Cien Serie A Mat, 2021, 115: Art 133).

With the development of remote sensing technology, remote sensing object detection has been widely applied in various fields, but it still faces some thorny challenges, such as the following: 1) the complexity of object scale changes in remote sensing images makes it difficult to improve the performance of small object detection and 2) remote sensing images have complex backgrounds and densely arranged small and weak objects, which pose a serious problem of feature interference. To alleviate these challenges, we propose an end-to-end adaptive feature separation network called AFSNet, which includes a scale-aware module (SAM) and a class-aware module (CAM). The SAM mainly enables feature maps of different resolutions to detect objects of different scales. Shallow feature maps mainly suppress the features of large objects they contain to focus on small object detection, while deep feature maps increase the detailed features of large objects they contain to focus on large object detection. The CAM is mainly used to distinguish the features in the feature map by category, separating the features of different categories into different channels, thus mitigating the problem of inter class feature interference, and blocking background interference. The effectiveness of this article has been proven on the NWPU VHR-10, IPIU-M, DIOR, and DOTA2.0 datasets. It can be widely applied in civilian, military, and other fields. Through experimental verification, our AFSNet achieved 97.70% mAP on the NWPU VHR-10 dataset, 78.9% mAP on the DIOR dataset, and 58.22% mAP on the DOTA2.0 dataset. Our code is available at: https://github.com/Xidian-AIGroup190726/AFSNet.

Carbon nanotubes (CNTs) cold cathode has excellent electron emission characteristics and showed its importance in vacuum electronic device applications. Facing various demand on electron beam with different devices, the cold cathode electron gun as a component for generating electron beam raises a challenge for controlling the beam which possess high-speed electrons due to the high driven field from a cold cathode. Here, a coplanar quadrupole focusing structure is proposed to adding in a CNT cold cathode electron gun to realize a multifunctional electron beam shape tailoring. In principle, the field emission electrons were first decelerated then adjusted by the focusing electrode modules to achieve multiple functions, including beam focusing, sheet beam adjusting, and beam shifting. In the experimental results, the area compression ratio of the electron beam was ~34.6; a round beam spot with a diameter of 2.76 mm was compressed to a sheet beam with a width of 0.15 mm; a beam position shifting was as large as 2.22 mm in radial cross section. This work demonstrates the feasibility of tailoring the beam shape of electron beam in a cold cathode gun according to the device application requirements.

Cellulose-based flexible sensors, characterized by outstanding biocompatibility, degradability, and rich surface chemistry, offer considerable promise for human health monitoring. Limited extensibility, however, predisposes these materials to mechanical damage like cracking, which compromises sensor stability. Integrating self-healing functionalities not only restores their mechanical and sensory performances but also prolongs their service life. This paper reviews the diverse self-healing mechanisms of cellulose-based sensors and examines the contributions of dynamic bonding to reconciling self-healing prerequisites, efficiency, and mechanical integrity. The discussion extends to the latest advancements in cellulose-based flexible self-healing sensors for tracking health indicators, including movement, body temperature, sweat, and respiration, while also contemplating their prospects and emerging challenges.

Objective:To evaluate the impact of the duration of breastfeeding on the intelligence of children.Materials and Methods:Eight electronic databases were searched to identify studies that investigated the impact of breastfeeding on the intelligence of children. Data were pooled, and the ratio of means (RoM) and the corresponding 95% confidence interval (95% CI) were calculated using a pairwise meta-analysis and network meta-analysis. Risk of bias was assessed using a tool developed by the CLARITY group. Data were analyzed using R version 3.5.1.Results:A total of 15 studies with 12,316 subjects were included in the review. Half of the studies were at low risk of bias. A meta-analysis indicated that breastfed children had a score 1.04-fold higher in intelligence tests compared with those that had never been breastfed (RoM: 1.04, 95% CI: 1.02–1.06, p< 0.05). Evidence from a network meta-analysis indicated that breastfeeding for ≤6 months resulted in score 1.04-fold higher in intelligence tests (RoM: 1.04, 95% CI: 1.03–1.06, p< 0.05) and children breastfed for >6 months had a score 1.06-fold higher (RoM: 1.06, 95% CI: 1.05–1.08, p< 0.05) than children that had never been breastfed. Thus, breastfeeding for >6 months demonstrated a slightly higher score than breastfeeding for ≤6 months (RoM: 1.02, 95% CI: 1.00–1.04, p< 0.05).Conclusion:Breastfeeding could significantly improve the intelligence of children, with a duration of >6 months showing a slight but significantly higher intelligence score than for ≤6 months.

Fire accidents often occur in environments characterized by severe air pollution, toxic gas emissions, and microbial growth, creating significant challenges for developing multifunctional portable healthcare devices. These devices must achieve high filtration efficiency, minimal pressure drop, and the capability to provide early warnings of toxic gas leaks. Triboelectric nanogenerators present a sustainable solution as self-powered energy converters for advanced healthcare applications. In this study, we grafted Ti3C2Tx/MoS2nanohybrid materials, which form Schottky heterojunctions, onto cellulose diacetate using tetraethyl orthosilicate, followed by electrospinning to produce nanofibrous films. When paired with a negatively charged material, the resulting device achieved an optimal balance with a low-pressure drop (52Pa) and high filtration efficiency (98.72% for PM0.3). It also demonstrated exceptional stability under high-temperature and high-humidity conditions. Notably, the device maintained rapid sterilization within 15minutes and consistent filtration performance even after multiple washes. Furthermore, the device exhibited precise detection of trace amounts of NH3(0.1 ppm) and demonstrated a rapid response, achieving an 86% response rate within 2seconds for 100 ppm NH3, providing an early warning 28seconds faster than commercial NH₃ monitors. This study introduces a novel approach to the development of multifunctional, self-powered, wearable medical devices that offer high-efficiency air filtration and sterilization, breath monitoring, and rapid toxic gas leakage detection in harsh environments.

Let G=(V,E)be a locally finite connected weighted graph, and Δ be the usual graph Laplacian. In this article, we study blow-up problems for the nonlinear parabolic equation ut=Δu + f(u)on G. The blow-up phenomenons for ut=Δu + f(u)are discussed in terms of two cases: (i) an initial condition is given; (ii) a Dirichlet boundary condition is given. We prove that if fsatisfies appropriate conditions, then the corresponding solutions will blow up in a finite time.

High-rate hardcase lithium-ion batteries used in electromagnetic launch(EML) applications operate under continuous high-current pulse conditions, accompanied by intense heat generation and large internal temperature gradients. Accurate detection of the characteristics of their internal temperature field is difficult using conventional temperature measurement methods, which in turn causes difficulties in defining their safe-use boundaries. In this paper, we proposed a method for embedding long-life optical fiber grating temperature sensors inside a high-rate hardcase lithium-ion battery to achieve long-period in-situ detection of the temperature field inside the battery. The room temperature aging study and constant current charge/discharge results showed no significant difference in performance between the two sensors-embedded batteries and the same batch of battery after 20 months of preparation. The temperature calibration results showed that the relative error of temperature measurement of the ten embedded fiber grating temperature sensors did not exceed 0.5 K at all 3 stages. This test data can guide optimal design and guarantee the ultimate safe use of the high-rate battery.

Co–B has outstanding catalytic activity in catalyzing the hydrolysis of ammonia borane (AB) to produce hydrogen and has been widely studied and applied. However, the high surface energy and magnetic properties of Co–B catalysts make the particles easily agglomerate and have few active sites. Herein, a novel compound Ag/Co–B/CTAB with high catalytic activity is prepared by chemical reduction. The compound Ag/Co–B/CTAB is characterized by Fourier‐transform infrared, X‐Ray diffraction, X‐Ray photoelectron spectroscopy, and transmission electron microscopy, which show that Ag+in the compound Ag/Co–B/CTAB is reduced entirely to Ag acting as an atomic barrier to improve dispersion of Co–B due to a large specific surface area (168.8153 m2g−1). Moreover, the performance of Co–B doped with Ag in the hydrolysis of AB is studied and the compound Ag/Co–B/CTAB has a hydrogen generation rate of 17.685 L min−1·g−1at 30 °C with a low activation energy of 13.33 kJ mol−1. The work on the Ag/Co–B/CTAB catalyst provides an essential insight into developing efficient hydrogen‐producing catalysts by regulating the electron transfer between metal and Co–B. The Ag/Co–B/CTAB catalyst has high catalytic activity with a hydrogen production rate of 17.685 L min−1·g−1and a low activation energy of 13.33 kJ·mol−1at 30 °C. Ag acts as an atomic barrier to avoid the agglomeration of Co–B particles. CTAB controls the morphology of catalyst. The electron transfer between Co–B and Ag provides an idea for hydrolysis catalysts.

A label-free and reagentless immunosensor based on localized surface plasmon resonance (LSPR) sensing was developed for the detection of salbutamol (Sal). Silver triangular nanoparticles deposited on transparent indium tin oxide film glass were used as the sensing platform. The immunosensor was prepared by direct adsorption of antibody against Sal on the surface of silver triangular nanoparticles. LSPR bands were obtained by a basic UV-vis spectrophotometer in the transmission mode. The analytical performance of the biosensor for the detection of Sal was examined. Under the optimized conditions, a calibration plot for Sal was obtained with a linear range between 0.02 μg mL−1and 0.8 μg mL−1(r= 0.991). The detection limit was 0.01 μg mL−1. The proposed biosensor has been used to detect the concentration of Sal in pig complex feed and pork liver samples. It is believed that the plasmonic immunosensor is simple, cost-effective and can be easily used for the detection of Sal in cases of its abuse in animal feed for field analysis.

The frame structure combined with water- and heat-transfer capabilities fully satisfies the requirements of photothermal conversion materials in seawater evaporation applications. Meanwhile, it must integrate the characteristics of a high photothermal conversion rate, thermal management, and water transportation. Herein, lamellar porous films were successfully designed and synthesized by a simple ultrasonic-assisted vacuum filtration method. In this process, polystyrene sulfonate@carbon nanotubes/reduced graphene oxide (PSS@CNT/rGO) lamellar films were constructed by the one-dimensional synthesis of PSS@CNT self-assembled at the molecular scale and the two-dimensional matrix material rGO. It is worth noting that the lamellar film exhibits a high specific surface area (285.5 m2·g–1), which is reflected in its abundant nanopores. Among them, the porous network system composed of nanochannels can provide efficient water supply and steam-transfer ability and strengthen the heat insulation performance of thermal localization, which is beneficial to photothermal evaporation. The obtained PSS@CNT/rGO lamellar films achieved a condensed water yield of 1.825 kg·m–2·h–1under 1 sun illumination (1 kW·m–2), and their solar-vapor conversion efficiency was 97.1%. Simultaneously, the interaction between the water flow and the carbon material interface was also used to generate additional electric energy output. The maximum open-circuit voltage of 0.46 V was generated at both termini of the PSS@CNT/rGO lamellar film, which successfully realized the multieffect utilization of energy. These results show that the multistage assembly strategy is a facile and effective means for the development of an efficient evaporation photothermal film, which offers significant value in the field of photothermal seawater evaporation and power generation.

Let G=(V,E)be a locally finite, connected and weighted graph. We prove that, for a graph satisfying curvature dimension condition CDE′(n,0)and uniform polynomial volume growth of degree m, all non-negative solutions of the equation ∂tu=Δu+u1+αblow up in a finite time, provided that α=2m. We also consider the blow-up problem under certain conditions for volume growth and initial value. These results complement our previous work joined with Lin.

Prussian blue nanoprobes are widely studied and applied in tumor photothermal therapy (PTT) and magnetic resonance imaging (MRI), due to their low toxicity and excellent in vivo performance. However, the sizes of hitherto reported Prussian blue nanoprobes are generally larger than 50 nm, which greatly influence cell phagocytosis, in vivo circulation, and biodistribution. In this work, a novel method of doping zinc ions is used to control the size of Prussian blue nanoprobes. Consequently, the performances of the nanoprobes in PTT and MRI are both significantly improved. The results show that the minimum size of Prussian blue nanoprobes achieved by doping 10% zinc ions (abbreviated as SPBZn(10%)) is 3.8 ± 0.90 nm, and the maximum specific absorption coefficient, photothermal conversion efficiency, and longitudinal relaxation rates are 1.78 L g−1cm−1, 47.33%, and 18.40 mm−1s−1, respectively. In addition, the SPBZn(10%) nanoprobes provide excellent PTT efficacy on 4T1 tumor cells (killing rate: 90.3%) and breast cancer model (tumor inhibition rate: 69.4%). Toxicological experiment results show that the SPBZn(n%) nanoprobes exhibit no obvious in vitro cytotoxicity and they can be used safely in mice at doses below 100 mg kg−1. Therefore, SPBZn(10%) nanoprobes can potentially be used for effective cancer theranostics. In this work, a novel Zn2+doping of Prussian blue is employed to obtain ultrasmall SPBZn(10%) nanoprobe, which possess excellent photothermal therapy and magnetic resonance imaging contrast enhancement performances on 4T1 tumor cells and Balb/c mouse 4T1 breast cancer model. Leveraging these properties, SPBZn(10%) nanoprobes can be used as a potentially effective antitumor theranostic agent.

Aimed at the miniaturization of the power-supply system for electromagnetic launch (EML) system, this paper deals with the problem of high rate pulse discharge of lithium batteries in the EML system. In order to reduce the number of batteries on series-parallel to increase the energy density, the factors such as safety, exotherm and life cycle must be taken into consideration, and there is need for optimization in terms of selection and design as well as discharge control of the battery. According to the power requirements of the EML system, the battery safety and discharge ability are important indexes in the aspect of selection and design, which refer to the design principle for selected batteries and the design scheme for raising their discharge ability under the precondition of discharge, and in the aspect of discharge control, the balancing-discharge control strategy is adopted to reduce the duration of high-rate discharge and the heat generation and extend the service life of batteries according to the EML operating conditions. Finally a test platform is established for verification.