872 research outputs found

    A Memristive Spiking Neural Network Circuit with Selective Supervised Attention Algorithm

    No full text
    © 2022, IEEE. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1109/TCAD.2022.3228896Spiking neural networks (SNNs) are biologicallyplausible and computationally powerful. The current computingsystems based on the von Neumann architecture are almostthe hardware basis for the implementation of SNNs. However,performance bottlenecks in computing speed, cost, and energyconsumption hinder the hardware development of SNNs. Therefore,efficient non-Neumann hardware computing systems forSNNs remain to be explored. In this paper, a selective supervisedalgorithm for spiking neurons inspired by the selective attentionmechanism is proposed, and a memristive spiking neuron circuitas well as a memristive SNN circuit based on the proposedalgorithm are designed. The memristor realizes the learningand memory of the synaptic weight. The proposed algorithmincludes a top-down selective supervision method and a bottomupselective supervision method. Compared with other supervisedalgorithms, the proposed algorithm has excellent performance onsequence learning. Moreover, top-down and bottom-up attentionencoding circuits are designed to provide the hardware foundationfor encoding external stimuli into top-down and bottomupattention spikes, respectively. The proposed memristive SNNcircuit can perform classification on the MNIST dataset and theFashion-MNIST dataset with superior accuracy after learninga small number of labeled samples, which greatly reduces thecost of manual annotation and improves the supervised learningefficiency of the memristive SNN circuit.Peer reviewe

    Characterization and multilocus sequence typing of Clostridium perfringens isolated from patients with diarrhoea and food poisoning in Tai'an region, China

    No full text
    Objectives: Clostridium perfringens (C. perfringens) is a significant opportunistic pathogen. This study aims to examine the occurrence of C. perfringens in patients with diarrhoea and food poisoning and compare the genetic similarities with strains found in poultry retail markets and poultry farms in the same city (Tai'an, China). Methods: Clostridium perfringens was isolated from 30 human faecal samples and genotyped using multiplex PCR. The antimicrobial susceptibility test was conducted using the Kirby-Bauer disk diffusion method. Genetic relationships were analysed through Multi-locus sequence typing (MLST) and Phylogenetic analysis. Results: The positive rate of C. perfringens was found to be 96.67%. Among the positive samples, 91.67% of the faecal samples from patients with food poisoning contained type F strains of C. perfringens, while only 16.67% of the samples from diarrhoea cases contained type F. The drug susceptibility test revealed that the majority of isolates displayed broad-spectrum antimicrobial resistance. Out of the 57 isolates tested for drug susceptibility, 89.47% demonstrated resistance to at least three antibiotics. The MLST results indicated that strains originating from the same host and environment tended to be more closely related. However, certain strains associated with food poisoning and diarrhoea in patients shared the same ST and CC as some strains found in the retail market. These strains were also found to be phylogenetically similar to some retail market strains, suggesting potential risks to human health. Conclusions: Therefore, it is crucial to enhance the management of poultry retail markets in order to mitigate these associated risks

    A family of memristive multibutterfly chaotic systems with multidirectional initial-based offset boosting

    No full text
    © 2023 Elsevier Ltd. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.chaos.2023.113518Memristors are commonly used to construct memristive chaotic systems with complex dynamics because of their strong nonlinearity and unique memory effects. In this paper, a simplified multi-piecewise memristor is applied for designing a family of memristive multibutterfly chaotic systems (MMBCSs). By coupling different numbers of the simplified multi-piecewise memristors into a modified Sprott C system, three MMBCSs are constructed. Theoretical analysis and numerical simulations show that the three MMBCSs can not only generate connected 1D(direction)-, 2D(plane)-, and 3D(space)-multibutterfly chaotic attractors (MBCAs), respectively, but also can respectively produce unconnected 1D-, 2D-, and 3D-MBCAs. Also, the number and position of butterfly attractors can be easily controlled by switching the memristor’s integer parameters and initial states, respectively. More importantly, the constructed three MMBCSs exhibit different initial-based offset boosting including 1D-, 2D-, and 3D-boosting behaviors, respectively. Especially, the 3D-initial-offset behavior is found in chaotic systems at the first time. Furthermore, we further implement the physical circuit of the three MMBCSs, and various typical dynamical behaviors are demonstrated by hardware experiments and Multisim simulations. Finally, a medical image encryption solution for online medical treatment is designed based on the proposed MMBCSs.Peer reviewe

    Oligotrophic microbes are recruited to resist multiple global change factors in agricultural subsoils

    No full text
    An increasing number of anthropogenic pressures can have negative effects on biodiversity and ecosystem functioning. However, our understanding of how soil microbial communities and functions in response to multiple global change factors (GCFs) is still incomplete, particularly in less frequently disturbed subsoils. In this study, we examined the impact of different levels of GCFs (0–9) on soil functions and bacterial communities in both topsoils (0–20 cm) and subsoils (20–40 cm) of an agricultural ecosystem, and characterized the intrinsic factors influencing community resistance based on microbial life history strategy. Our experimental results showed a decline in soil multifunctionality, bacterial diversity, and community resistance as the number of GCFs increased, with a more drastic reduction in community resistance of subsoils. Specifically, we observed a significantly positive relationship between the oligotroph/copiotroph ratio and community resistance in subsoils, which was also verified by the negative correlation between 16S rRNA operon (rrn) copy number and community resistance. Structural equation modeling further revealed the direct effects of community resistance in promoting the ecosystem functioning, regardless of top- and subsoils. Therefore, these results suggested that subsoils may recruit more oligotrophic microbes to enhance their originally weaker community resistance under multiple GCFs, which was essential for maintaining sustainable agroecological functions and services. Overall, our study represents a significant advance in linking microbial life history strategy to the resistance of belowground microbial community and functionality

    Recent research progress on imbibition system of nanoparticle-surfactant dispersions

    Get PDF
    Nanotechnology has been increasingly applied in the petroleum industry in recent years. In particular, dispersions consisting of nanoparticles and surfactants have been widely investigated. The imbibition system compounded by nanoparticle and surfactant was found to display a high efficiency in enhancing oil recovery. This paper briefly reviews the factors influencing imbibition efficiency. At the same time, the application and mechanism of the imbibition system of nanoparticle-surfactant dispersion in the field of enhanced oil recovery are introduced. Additionally, the limitations and challenges that the imbibition system of nanoparticle-surfactant dispersions may face in enhanced oil recovery applications are put forward. The current work reveals that the imbibition system with nanoparticle-surfactant dispersion is an ideal candidate for enhanced oil recovery in tight and low-permeability reservoirs.Document Type: Invited reviewCited as: Shao, W., Yang, J., Wang, H., Chang, J., Wu, H., Hou, J. Recent research progress on imbibition system of nanoparticle-surfactant dispersions. Capillarity, 2023, 8(2): 34-44. https://doi.org/10.46690/capi.2023.08.0

    Spontaneous Remission of Pediatric Undescended Testis Torsion during Color Doppler Ultrasound Examination

    No full text
    Undescended testis or cryptorchidism is the most common reproductive system disease in children. About 3% of full-term and 30% of premature male infants are born with one or both testicles undescended. Most cryptorchidism is asymptomatic and is occasionally found due to inguinal pain caused by testicular torsion. Herein, we presented a case of pediatric patient with abdominal pain as initial symptom who was found the left inguinal cryptorchidism complicated by testicular torsion, and then spontaneous remission during the color Doppler ultrasonography examination

    Nonvolatile CMOS memristor, reconfigurable array and its application in power load forecasting

    Get PDF
    © 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This is the accepted manuscript version of a conference paper which has been published in final form at https://doi.org/10.1109/TII.2023.3341256The high cost, low yield, and low stability of nano-materials significantly hinder the application and development of memristors. To promote the application of memristors, researchers proposed a variety of memristor emulators to simulate memristor functions and apply them in various fields. However these emulators lack nonvolatile characteristics, limiting their scope of application. This paper proposes an innovative nonvolatile memristor circuit based on complementary metal-oxide-semiconductor (CMOS) technology, expanding the horizons of memristor emulators. The proposed memristor is fabricated in a reconfigurable array architecture using the standard CMOS process, allowing the connection between memristors to be altered by configuring the on-off state of switches. Compared to nano-material memristors, the CMOS nonvolatile memristor circuit proposed in this paper offers advantages of low manufacturing cost and easy mass production, which can promote the application of memristors. The application of the reconfigurable array is further studied by constructing an Echo State Network (ESN) for short-term load forecasting in the power system.Peer reviewe

    Impact of campus living conditions on Chinese medical school students’ mental health during the COVID-19 campus lockdown: the chain mediating role of cognitive reappraisal and expression suppression

    Get PDF
    ObjectiveTo investigate the effect of changes in campus living conditions related to the Corona Virus Disease 2019 (COVID-19) pandemic on medical school students’ mental health status, to explore the mediating role of emotion regulation strategies, and to provide effective suggestions for promoting medical school students’ mental health.MethodsA self-report questionnaire, an emotion regulation questionnaire (ERQ), and psychological questionnaires for emergent events of public health (PQEEPH) were used to interview 998 medical school students who experienced campus lockdowns during the COVID-19 pandemic.ResultsThe mean total PQEEPH score was 3.66 ± 3.06. The degrees of inconvenience in daily life and change in routine and expression suppression as an emotion regulation strategy were significantly positively correlated with all PQEEPH dimensions. Cognitive reappraisal was significantly negatively associated with depression, neurosis, obsessive–compulsive anxiety, and hypochondriasis (ps < 0.05). Cognitive reappraisal and expression suppression demonstrated a chain mediating role between the degree of inconvenience in life and mental health and between the degree of change in routine and mental health (F = 32.883, 41.051, ps < 0.05).ConclusionCampus lockdown management significantly impacts medical school students’ mental health. Extensive use of cognitive reappraisal and expression suppression can reduce students’ adverse psychological reactions during campus lockdowns to an extent

    P-Doping a Porous Carbon Host Promotes the Lithium Storage Performance of Red Phosphorus

    No full text
    Red phosphorus (RP) is a promising anode material for use in lithium-ion batteries (LIBs) due to its high theoretical specific capacity (2596 mA h g-1). However, the practical use of RP-based anodes has been challenged by the material’s low intrinsic electrical conductivity and poor structural stability during lithiation. Here, we describe a phosphorus-doped porous carbon (P-PC) and disclose how the dopant improves the Li storage performance of RP that was incorporated into the P-PC (designated as RP@P-PC). P-doping porous carbon was achieved using an in situ method wherein the heteroatom was added as the porous carbon was being formed. The phosphorus dopant effectively improves the interfacial properties of the carbon matrix as subsequent RP infusion results in high loadings, small particle sizes, and uniform distribution. In half-cells, an RP@P-PC composite was found to exhibit outstanding performance in terms of the ability to store and utilize Li. The device delivered a high specific capacitance and rate capability (1848 and 1111 mA h g-1 at 0.1 and 10.0 A g-1, respectively) as well as excellent cycling stability (1022 mA h g-1 after 800 cycles at 2.0 A g-1). Exceptional performance metrics were also measured when the RP@P-PC was used as an anode material in full cells that contained lithium iron phosphate as the cathode material. The methodology described can be extended to the preparation of other P-doped carbon materials that are employed in contemporary energy storage applications.11Nsciescopu
    corecore