18 research outputs found

    Investigation on Photovoltaic Performance based on Matchstick-Like Cu2S–In2S3Heterostructure Nanocrystals and Polymer

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    In this paper, we synthesized a novel type II cuprous sulfide (Cu2S)–indium sulfide (In2S3) heterostructure nanocrystals with matchstick-like morphology in pure dodecanethiol. The photovoltaic properties of the heterostructure nanocrystals were investigated based on the blends of the nanocrystals and poly(2-methoxy-5-(2′-ethylhexoxy)-p-phenylenevinylene) (MEH-PPV). In comparison with the photovoltaic properties of the blends of Cu2S or In2S3nanocrystals alone and MEH-PPV, the power conversion efficiency of the hybrid device based on blend of Cu2S–In2S3and MEH-PPV is enhanced by ~3–5 times. This improvement is consistent with the improved exciton dissociation or separation and better charge transport abilities in type II heterostructure nanocrystals

    Secrecy Performance Analysis of Cognitive Sensor Radio Networks with an EH-Based Eavesdropper

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    Security and privacy are crucial for cognitive sensor radio networks (CSRNs) due to the possible eavesdropping between secondary sensors and the secondary fusion center. Motivated by this observation, we investigate the physical layer security performance of CSRNs with an external energy harvesting (EH)-based eavesdropper. Considering the underlay working paradigm of CSRNs, the transmit power of the secondary sensor node must be adjusted to guarantee the quality-of-service ( Q o S ) of the primary user. Hence, two different interference power constraint scenarios are studied in this paper. To give an intuitive insight into the secrecy performance of the considered wiretap scenarios, we have derived the closed-form analytical expressions of secrecy outage probability for both of the considered cases. Monte Carlo simulation results are also performed to verify the theoretical analysis derived, and show the effect of various parameters on the system performance

    Secure Outage Analysis of Buffer-Aided Cognitive Relay Networks with Multiple Primary Users

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    The Relationships between Parenting Practices and Child Health-Related Behaviors in Children with Intellectual Disability: The Moderating Role of Child Body Weight Status

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    This study aimed to examine the associations between parenting practices and child health-related behaviors, and the moderating role of child body weight status in children with intellectual disability (ID). A cross-sectional study was conducted among a sample of children with ID in Hong Kong; 440 participants were included in this study. All the variables investigated were collected from questionnaires, except body weight status, which was objectively measured. Logistic regression analysis was used to examine the associations between parenting practices and children’s unhealthy behaviors. Interaction items were added to investigate the moderation effect of child body weight status, adjusting for significant background characteristics. Results showed that the parenting practices of “restricting access to unhealthy food and sedentary behaviors (RA)” (OR range: 0.63–0.64) and “using food or sedentary behaviors as rewards (UR)” (OR range: 1.28–1.60) were significantly associated with some eating behaviors, but not with sedentary behaviors. Body weight status significantly moderated these associations. Only RA showed favorable effects on some eating behaviors in children with overweight and obesity (OR range: 0.17–0.28), whereas the effects of UR differed by body weight status. Future research should focus on developing educational interventions which encourage parents to use practices that are tailored towards children’s individual characteristics

    Theory, technology and practice of shale gas three-dimensional development: A case study of Fuling shale gas field in Sichuan Basin, SW China

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    In the Jiaoshiba block of the Fuling shale gas field, the employed reserves and recovery factor by primary well pattern are low, no obvious barrier is found in the development layer series, and layered development is difficult. Based on the understanding of the main factors controlling shale gas enrichment and high production, the theory and technology of shale gas three-dimensional development, such as fine description and modeling of shale gas reservoir, optimization of three-dimensional development strategy, highly efficient drilling with dense well pattern, precision fracturing and real-time control, are discussed. Three-dimensional development refers to the application of optimal and fast drilling and volume fracturing technologies, depending upon the sedimentary characteristics, reservoir characteristics and sweet spot distribution of shale gas, to form “artificial gas reservoir” in a multidimensional space, so as to maximize the employed reserves, recovery factor and yield rate of shale gas development. In the research on shale gas three-dimensional development, the geological + engineering sweet spot description is fundamental, the collaborative optimization of natural fractures and artificial fractures is critical, and the improvement of speed and efficiency in drilling and fracturing engineering is the guarantee. Through the implementation of three-dimensional development, the overall recovery factor in the Jiaoshiba block has increased from 12.6% to 23.3%, providing an important support for the continuous and stable production of the Fuling shale gas field

    Serum metabolism alteration behind different etiology, diagnosis, and prognosis of disorders of consciousness

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    Abstract Background Patients with disorders of consciousness (DoC) exhibit varied revival outcomes based on different etiologies and diagnoses, the mechanisms of which remain largely unknown. The fluctuating clinical presentations in DoC pose challenges in accurately assessing consciousness levels and prognoses, often leading to misdiagnoses. There is an urgent need for a deeper understanding of the physiological changes in DoC and the development of objective diagnostic and prognostic biomarkers to improve treatment guidance. Methods To explore biomarkers and understand the biological processes, we conducted a comprehensive untargeted metabolomic analysis on serum samples from 48 patients with DoC. Patients were categorized based on etiology (TBI vs. non-TBI), CRS-R scores, and prognosis. Advanced analytical techniques, including PCA and OPLS-DA models, were employed to identify differential metabolites. Results Our analysis revealed a distinct separation in metabolomic profiles among the different groups. The primary differential metabolites distinguishing patients with varying etiologies were predominantly phospholipids, with a notable decrease in glycerophospholipids observed in the TBI group. Patients with higher CRS-R scores exhibited a pattern of impaired carbohydrate metabolism coupled with enhanced lipid metabolism. Notably, serum concentrations of both LysoPE and PE were reduced in patients with improved outcomes, suggesting their potential as prognostic biomarkers. Conclusions Our study underscores the critical role of phospholipid metabolism in the brain’s metabolic alterations in patients with DoC. It identifies key biomarkers for diagnosis and prognosis, offering insights that could lead to novel therapeutic targets. These findings highlight the value of metabolomic profiling in understanding and potentially treating DoC

    Effects of a School-Based Physical Activity Intervention for Obesity, Health-Related Physical Fitness, and Blood Pressure in Children with Intellectual Disability: A Randomized Controlled Trial

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    Children with intellectual disability (ID) are more vulnerable to health conditions than their typically developing peers. Evidence of effective interventions is scarce. A randomized controlled trial was conducted in 30 overweight and obese children with intellectual disability (ID) in China to evaluate a 12-week school-based physical activity intervention for obesity, health-related physical fitness (HRPF), and blood pressure. The intervention consisted of 24 physical activity (PA) sessions (2 sessions/week, 60 min/session), with exercise intensity progressively increasing from a moderate level to a vigorous level. All participants were followed up for 12 weeks after the intervention period to evaluate sustained effects. Outcomes were repeatedly measured at baseline, after the intervention, and after follow-up. The intervention was effective in reducing some obesity-related outcomes (including weight and body mass index) and improving some HRPF-related outcomes (including the 6 min walk test and the 30 s sit-to-stand test), with the significant effects being sustained after the 12-week follow-up. No effect was observed on blood pressure. The findings of this study contribute to the development and implementation of PA interventions to reduce obesity and improve HRPF in children with ID

    Influence of Grid Aperture Ratio on Electron Transmittance and Electron Beam Spot Size in Field Emission Processes of Carbon Nanotubes

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    Field emission is an important work mode for electron sources, and carbon nanotubes (CNTs) have been extensively studied for their good emission properties. It is well known that the parameters of the grid deeply influence the field emission performance of CNTs, a relationship that requires further elucidation. Therefore, in this study, the relationship between the grid aperture ratio and electron transmittance was studied through simulations and experiments. This study’s results indicate that the electron transmittance improved as the grid aperture ratio increased. Meanwhile, electron beam spot simulations and imaging experiments indicate that an increased grid aperture ratio will expand the cathode electron divergence, leading to a larger electron beam spot size. These results demonstrate that there is a trade-off in maintaining the grid aperture ratio between high electron transmittance and relatively small electron beam spot size, and the optimum grid aperture ratio is between 75% and 85%. These results will provide a reference for the design and optimization of X-ray tubes and other electron sources

    Interventions for health‐related physical fitness and overweight and obesity in children with intellectual disability: Systematic review and meta‐analysis

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    International audienceBackgroundPoor health-related physical fitness (HRPF) and overweight and obesity are common health problems for children with intellectual disability. This study aimed to review existing lifestyle intervention studies, and identify effective strategies for this population.MethodsA systematic search was undertaken in three databases. The random-effects model was used to pool the weighted results by inverse variance methods, and the I2 statistic was applied to assess heterogeneity among the included studies.ResultsMost of the identified interventions (27/29) adopted physical activity (PA). For obesity-related outcomes, the results showed no significant effect of PA studies on reducing obesity. For HRPF outcomes, significant effects were found on 6-min walk distance (51.86 m, 95% CI [16.49, 87.22], p < .05).ConclusionsPA is the predominant intervention component adopted and may contribute to improving cardiopulmonary fitness; but the lack of research limits our ability to draw any confirmed conclusion on obesity-related outcomes and other HRPF outcomes
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