Background:Globally,the use of community pharmacies and pharmacists in the delivery of vaccination services has been hampered by several factors,laws,and regulations that do not support pharmacists to participate in t...Background:Globally,the use of community pharmacies and pharmacists in the delivery of vaccination services has been hampered by several factors,laws,and regulations that do not support pharmacists to participate in the delivery of vaccination services.With the advent of COVID-19 pandemic,many countries have included community pharmacists and pharmacies in vaccination services to improve coverage.This study described the delivery of vaccination services in community pharmacies using the COVID-19 experience and how their involvement impacted vaccination coverage in Nigeria.It also exposed how this experience can be used to support policy revisions to formally recognize pharmacists in immunization delivery.Methods:A descriptive cross-sectional study was conducted among 474 community pharmacists in two southwestern States in Nigeria,using a semi-structured questionnaire.It determines the number of community pharmacists who have been trained in the delivery of vaccination services,the types of vaccination services provided,and vaccines administered in their pharmacies.Data were analyzed with descriptive and inferential statistics and p-value at≤0.05.Results:Response rate was 86.7%.Less than half of the respondents(40.1%)had undergone vaccination training.Of the 129(31.4%)respondents that provide vaccination services,72(55.8%)administer vaccines in their pharmacies.Out of these 72 respondents;45(62.5%)were administering vaccines before their involvement in COVID-19 vaccine administration;57(79.2%)of the health personnel who administer vaccines were pharmacists;60(83.3%)of them administer vaccines on request;22(30.6%)administered COVID-19 vaccines only;and only 7(9.7%)of the respondents had administered over 500 doses of COVID-19 vaccines.Training in vaccination was associated with the vaccination services provided(p<0.05).Respondents suggested government support through legal framework and policy review,training and empowering pharmacists in vaccine administration,and recognition of community pharmacists as PHC providers.展开更多
Influenza is a significant global public health challenge,with seasonal epidemics imposing substantial burdens on healthcare systems and vulnerable populations,causing 3 to 5 million severe cases and 290,000 to 650,00...Influenza is a significant global public health challenge,with seasonal epidemics imposing substantial burdens on healthcare systems and vulnerable populations,causing 3 to 5 million severe cases and 290,000 to 650,000 respiratory-related deaths worldwide each year[1].Vaccines are an effective means of preventing influenza.In recent years,China has made progress in vaccine development and immunization strategies.The population is recommended to receive influenza vaccines annually;however,their coverage remain suboptimal[2].The World Health Organization(WHO)highlights that all countries should consider implementing seasonal influenza immunization programs,with priority groups determined based on local epidemiological contexts.In alignment with the Immunization Agenda 2030,the use of seasonal influenza vaccines contributes to strengthening the life course of immunization and serves as a critical component for addressing influenza pandemics,as outlined in the WHO Global Influenza Strategy 2019-2030.展开更多
As the problem of surface garbage pollution becomes more serious,it is necessary to improve the efficiency of garbage inspection and picking rather than traditional manual methods.Due to lightness,Unmanned Aerial Vehi...As the problem of surface garbage pollution becomes more serious,it is necessary to improve the efficiency of garbage inspection and picking rather than traditional manual methods.Due to lightness,Unmanned Aerial Vehicles(UAVs)can traverse the entire water surface in a short time through their flight field of view.In addition,Unmanned Surface Vessels(USVs)can provide battery replacement and pick up garbage.In this paper,we innovatively establish a system framework for the collaboration between UAV and USVs,and develop an automatic water cleaning strategy.First,on the basis of the partition principle,we propose a collaborative coverage path algorithm based on UAV off-site takeoff and landing to achieve global inspection.Second,we design a task scheduling and assignment algorithm for USVs to balance the garbage loads based on the particle swarm optimization algorithm.Finally,based on the swarm intelligence algorithm,we also design an autonomous obstacle avoidance path planning algorithm for USVs to realize autonomous navigation and collaborative cleaning.The system can simultaneously perform inspection and clearance tasks under certain constraints.The simulation results show that the proposed algorithms have higher generality and flexibility while effectively improving computational efficiency and reducing actual cleaning costs compared with other schemes.展开更多
Objective:To assess the complete vaccination coverage and timeliness of childhood vaccinations among Indigenous children in Peninsular Malaysia.Methods:The study utilized data from the 2022 Orang Asli Health Survey,a ...Objective:To assess the complete vaccination coverage and timeliness of childhood vaccinations among Indigenous children in Peninsular Malaysia.Methods:The study utilized data from the 2022 Orang Asli Health Survey,a cross-sectional survey conducted among a representative sample of Orang Asli in Peninsular Malaysia.A total of 68 villages were randomly selected from a pool of 853 villages,encompassing diverse geographic and sociodemographic contexts with a total of 15950 respondents Orang Asli successfully interviewed.However,this study only utilized data from surveyed children aged 12 to 59 months with a total of 1551 children included.Validated structured questionnaires were used to collect sociodemographic data and health status,with nurses verifying vaccination records.Children who received all nine primary vaccinations were defined as having complete vaccination while those who received vaccine within the recommended time were defined as having timely vaccination.Data analysis was conducted using IBM SPSS version 25.0,focusing on descriptive analyses of children's vaccination status.Results:The prevalence of overall complete vaccination among Indigenous children was 87.7%,while timely vaccination was only 40.3%.The prevalence of complete vaccination for Bacillus Calmette-Guérin(BCG),the first dose of hepatitis B,three doses of DTaP-IPV-Hib,and measles,mumps,and rubella(MMR)was above 95.0%,except for the second and third doses of hepatitis B.The prevalence of timely vaccination ranged from above 95.0%for vaccines given at birth,gradually decreasing with increasing age to 57.5%for the first dose of MMR.Moreover,the completion rates for three doses of DtaP-IPV-Hib and the initial dose of MMR surpassed 90%among Indigenous children aged 12-23 months,yet the timeliness remained at a moderate level.Conclusions:While the overall complete vaccination coverage among Indigenous children in Malaysia is relatively high,there are concerning disparities in the timeliness of vaccination,particularly as children age.展开更多
Research has shown considerable variability in whitecap coverage(W)under low to moderate wind conditions.During an expedition to the Northwestern Pacific,oceanographic variables and photographic measurements were coll...Research has shown considerable variability in whitecap coverage(W)under low to moderate wind conditions.During an expedition to the Northwestern Pacific,oceanographic variables and photographic measurements were collected to investigate the influence of wave-induced stress on W within these wind ranges.The friction velocity was recalculated based on turbulent stress,and wind profiles were modified to account for wave-induced stress and swell presence on the sea surface.The study examined W’s relationship with multiple parameters,including friction velocity(u*),breaking wave Reynolds numbers,wavesea Reynolds numbers,and wave age.The analysis utilized both conventional u*and turbulent stress-based friction velocity(u*turb).When utilizing u*turb rather than u*,the estimation model’s fitting results revealed an increase in correlation coefficient(R2)from 0.51 to 0.62,and a decrease in root mean square error(RMSE)from 0.0652 to 0.0574.Additionally,when parameterizing W using the windsea Reynolds number,with u_(*turb) replacing u*and wind wave height substituting mixed wave height,the R^(2) increased from 0.38 to 0.53,and the RMSE decreased from 0.0737 to 0.0668.The results demonstrate that calculating u*using the turbulent stress-based method,along with wind wave height and peak wave speed of mixed waves,yields stronger correlation with W.This correlation improvement stems from the inhibition of wave breaking by swell and wave-induced stress.The integration of turbulent stress and wind wave field measurements enhances the understanding of relationships between W and various parameters.However,swell effects on wind profiles do not substantially affect W estimation using wind speed-related parameters.展开更多
Complex multi-area collaborative coverage path planning in dynamic environments poses a significant challenge for multi-fixed-wing UAVs(multi-UAV).This study establishes a comprehensive framework that incorporates UAV...Complex multi-area collaborative coverage path planning in dynamic environments poses a significant challenge for multi-fixed-wing UAVs(multi-UAV).This study establishes a comprehensive framework that incorporates UAV capabilities,terrain,complex areas,and mission dynamics.A novel dynamic collaborative path planning algorithm is introduced,designed to ensure complete coverage of designated areas.This algorithm meticulously optimizes the operation,entry,and transition paths for each UAV,while also establishing evaluation metrics to refine coverage sequences for each area.Additionally,a three-dimensional path is computed utilizing an altitude descent method,effectively integrating twodimensional coverage paths with altitude constraints.The efficacy of the proposed approach is validated through digital simulations and mixed-reality semi-physical experiments across a variety of dynamic scenarios,including both single-area and multi-area coverage by multi-UAV.Results show that the coverage paths generated by this method significantly reduce both computation time and path length,providing a reliable solution for dynamic multi-UAV mission planning in semi-physical environments.展开更多
In the current era of intelligent technologies,comprehensive and precise regional coverage path planning is critical for tasks such as environmental monitoring,emergency rescue,and agricultural plant protection.Owing ...In the current era of intelligent technologies,comprehensive and precise regional coverage path planning is critical for tasks such as environmental monitoring,emergency rescue,and agricultural plant protection.Owing to their exceptional flexibility and rapid deployment capabilities,unmanned aerial vehicles(UAVs)have emerged as the ideal platforms for accomplishing these tasks.This study proposes a swarm A^(*)-guided Deep Q-Network(SADQN)algorithm to address the coverage path planning(CPP)problem for UAV swarms in complex environments.Firstly,to overcome the dependency of traditional modeling methods on regular terrain environments,this study proposes an improved cellular decomposition method for map discretization.Simultaneously,a distributed UAV swarm system architecture is adopted,which,through the integration of multi-scale maps,addresses the issues of redundant operations and flight conflicts inmulti-UAV cooperative coverage.Secondly,the heuristic mechanism of the A^(*)algorithmis combinedwith full-coverage path planning,and this approach is incorporated at the initial stage ofDeep Q-Network(DQN)algorithm training to provide effective guidance in action selection,thereby accelerating convergence.Additionally,a prioritized experience replay mechanism is introduced to further enhance the coverage performance of the algorithm.To evaluate the efficacy of the proposed algorithm,simulation experiments were conducted in several irregular environments and compared with several popular algorithms.Simulation results show that the SADQNalgorithmoutperforms othermethods,achieving performance comparable to that of the baseline prior algorithm,with an average coverage efficiency exceeding 2.6 and fewer turning maneuvers.In addition,the algorithm demonstrates excellent generalization ability,enabling it to adapt to different environments.展开更多
Published proof test coverage(PTC)estimates for emergency shutdown valves(ESDVs)show only moderate agreement and are predominantly opinion-based.A Failure Modes,Effects,and Diagnostics Analysis(FMEDA)was undertaken us...Published proof test coverage(PTC)estimates for emergency shutdown valves(ESDVs)show only moderate agreement and are predominantly opinion-based.A Failure Modes,Effects,and Diagnostics Analysis(FMEDA)was undertaken using component failure rate data to predict PTC for a full stroke test and a partial stroke test.Given the subjective and uncertain aspects of the FMEDA approach,specifically the selection of component failure rates and the determination of the probability of detecting failure modes,a Fuzzy Inference System(FIS)was proposed to manage the data,addressing the inherent uncertainties.Fuzzy inference systems have been used previously for various FMEA type assessments,but this is the first time an FIS has been employed for use with FMEDA.ESDV PTC values were generated from both the standard FMEDA and the fuzzy-FMEDA approaches using data provided by FMEDA experts.This work demonstrates that fuzzy inference systems can address the subjectivity inherent in FMEDA data,enabling reliable estimates of ESDV proof test coverage for both full and partial stroke tests.This facilitates optimized maintenance planning while ensuring safety is not compromised.展开更多
This study utilized a computer application developed in Visual StudioTM using C# to extract pixel samples (RGB) from multiple images (26 images obtained from August 20, 2024, to September 22, 2024), of a purslane pot ...This study utilized a computer application developed in Visual StudioTM using C# to extract pixel samples (RGB) from multiple images (26 images obtained from August 20, 2024, to September 22, 2024), of a purslane pot taken from a top-down perspective at a distance of 30 cm. These samples were projected into the CIELAB color space, and the extracted pixels were plotted on the a*b* plane, excluding the luminance value. A polygon was then drawn around all the plotted pixels, defining the color to be identified. Subsequently, the application analyzed another image to determine the number of pixels within the polygon. These identified pixels were transformed to white, and the percentage of these pixels relative to the total number of pixels in the image was calculated. This process yielded percentages for brown (soil), green (leaf cover), and pink (stem color). A single polygon was sufficient to accurately identify the green and brown colors in the images. However, due to varying lighting conditions, customized polygons were necessary for each image to accurately identify the stem color. To validate the green polygon’s accuracy in identifying purslane leaves, all leaves in the image were digitized in AutoCADTM, and the green area was compared to the total image area to obtain the observed green percentage. The green percentage obtained with the polygon was then compared to the observed green percentage, resulting in an R2 value of 0.8431. Similarly, for the brown color, an R2 value of 0.9305 was found. The stem color was not subjected to this validation due to the necessity of multiple polygons. The R2 values were derived from percentage data obtained by analyzing the total pixels in the images. When sampling to estimate the proportion and analyzing only the suggested sample size of pixels, R2 values of 0.93049 for brown and 0.8088 for green were obtained. The average analysis time to determine the brown soil percentage using the polygon (BP) for 26 images with an average size of 1070 × 1210 pixels was 44 seconds. In contrast, sampling to estimate the proportion reduced the analysis time to 0.9 seconds for the same number of images. This indicates that significant time savings can be achieved while obtaining similar results.展开更多
This paper proposes a novel blended hyper-cellular architecture for low-altitude aerial intelligent networks(LAINs)to provide agile coverage tailored to active air routes and takeoff/landing spots.Traditional cellular...This paper proposes a novel blended hyper-cellular architecture for low-altitude aerial intelligent networks(LAINs)to provide agile coverage tailored to active air routes and takeoff/landing spots.Traditional cellular networks struggle to meet the dynamic demands of low-altitude UAV communications due to their rigid structures.The hyper-cellular network(HCN)architecture separates control and traffic coverage,enabling flexible and energy-efficient operations.The key components include control base stations(CBSs)for wide-area signaling coverage and traffic base stations(TBSs)that can be dynamically activated based on traffic demands.The proposed solution also integrates space information networks(SINs)to enhance the coverage efficiency.Key technologies such as all-G CBS using RISC-V architecture,AI-powered radio maps for low-altitude environments,and agile TBS coverage adaptation are introduced with some preliminary studies.These designs aim to address challenges like mobility management,interference coordination,and the need for real-time spectrum sharing in blended satellite-terrestrial networks.The proposed solution offers a scalable and agile framework to support the rapidly growing demand for reliable,low-latency,and high-capacity UAV communications in urban environments.展开更多
In offshore maritime communication sys-tems,base stations(BSs)are employed along the coastline to provide high-speed data service for ves-sels in coastal sea areas.To ensure the line-of-sight propagation of BS-vessel ...In offshore maritime communication sys-tems,base stations(BSs)are employed along the coastline to provide high-speed data service for ves-sels in coastal sea areas.To ensure the line-of-sight propagation of BS-vessel links,high transceiver an-tenna height is required,which limits the number of geographically available sites for BS deployment,and imposes a high cost for realizing effective wide-area coverage.In this paper,the joint user association and power allocation(JUAPA)problem is investigated to enhance the coverage of offshore maritime systems.By exploiting the characteristics of network topology as well as vessels’motion in offshore communica-tions,a multi-period JUAPA problem is formulated to maximize the number of ships that can be simultane-ously served by the network.This JUAPA problem is intrinsically non-convex and subject to mixed-integer constraints,which is difficult to solve either analyt-ically or numerically.Hence,we propose an iterative augmentation based framework to efficiently select the active vessels,where the JUAPA scheme is iteratively optimized by the network for increasing the number of the selected vessels.More specifically,in each itera-tion,the user association variables and power alloca-tion variables are determined by solving two separate subproblems,so that the JUAPA strategy can be up-dated in a low-complexity manner.The performance of the proposed JUAPA method is evaluated by exten-sive simulation,and numerical results indicate that it can effectively increase the number of vessels served by the network,and thus enhances the coverage of off-shore systems.展开更多
A thoroughly mechanistic understanding of the electrochemical CO reduction reaction(eCORR)at the interface is significant for guiding the design of high-performance electrocatalysts.However,unintentionally ignored fac...A thoroughly mechanistic understanding of the electrochemical CO reduction reaction(eCORR)at the interface is significant for guiding the design of high-performance electrocatalysts.However,unintentionally ignored factors or unreasonable settings during mechanism simulations will result in false positive results between theory and experiment.Herein,we computationally identified the dynamic site preference change of CO adsorption with potentials on Cu(100),which was a previously unnoticed factor but significant to potential-dependent mechanistic studies.Combined with the different lateral interactions among adsorbates,we proposed a new C–C coupling mechanism on Cu(100),better explaining the product distribution at different potentials in experimental eCORR.At low potentials(from–0.4 to–0.6 V_(RHE)),the CO forms dominant adsorption on the bridge site,which couples with another attractively aggregated CO to form a C–C bond.At medium potentials(from–0.6 to–0.8 VRHE),the hollow-bound CO becomes dominant but tends to isolate with another adsorbate due to the repulsion,thereby blocking the coupling process.At high potentials(above–0.8 VRHE),the CHO intermediate is produced from the electroreduction of hollow-CO and favors the attraction with another bridge-CO to trigger C–C coupling,making CHO the major common intermediate for C–C bond formation and methane production.We anticipate that our computationally identified dynamic change in site preference of adsorbates with potentials will bring new opportunities for a better understanding of the potential-dependent electrochemical processes.展开更多
Urban vegetation plays a crucial role in regulating temperatures and heat waves in urban areas.However,the influence of vegetation coverage and its configuration on surface temperatures in different climate zones at a...Urban vegetation plays a crucial role in regulating temperatures and heat waves in urban areas.However,the influence of vegetation coverage and its configuration on surface temperatures in different climate zones at a national scale is unclear.To address this,we utilized high-resolution data to detect spatial patterns for 31 provincial capital cities in China.We integrated day and night surface temperatures to determine the influence of vegetative coverage and configuration on urban temperatures across different climate zones and city sizes.Our study revealed that a subtropical monsoon climate and medium-sized cities had the highest vegetative coverage and shape complexity.The best connectivity and agglomeration of vegetation were found in a temperate monsoon climate and large cities.In contrast,small cities,especially those under a temperate continental climate,had low vegetation coverage,high fragmentation,and weak agglomeration and connectivity.In addition,vegetative coverage had a negative impact on daytime surface temperatures,especially in large cities in a subtropical monsoon climate.However,an increase in vegetation coverage could result in warming at night in small cities in temperate continental climates.Although urban vegetation configuration also contributed to moderating surface temperatures,especially at night,they did not surpass the influence of vegetation coverage.The effect on nighttime temperatures of the configuration of vegetation increased by 3–6%relative to that of daytime temperatures,especially in large cities in a temperate monsoon climate.The contribution vegetation coverage and configuration interaction to cooling efficiency decreased at night,especially in medium-sized cities in a temperate continental climate by 3–5%.In addition,this study identified several moderating effects of natural and social factors on the relationship between urban vegetation coverage and surface temperatures.High duration of sunshine,low humidity and high wind speed significantly enhanced the negative impact of vegetation coverage on surface temperatures.In addition,the moderating effect of vegetation coverage was more pronounced in low population density cities and high gross domestic product.This study enhances understanding of the ecological functions of urban vegetation and provides a valuable scientific basis and strategic recommendations for optimizing urban vegetation and improving urban environmental quality.展开更多
The rapid acceleration of global warming and intensifying human activities have exacerbated the fragility and climate sensitivity of ecosystems worldwide,particularly in arid regions.Vegetation,a key component of ecos...The rapid acceleration of global warming and intensifying human activities have exacerbated the fragility and climate sensitivity of ecosystems worldwide,particularly in arid regions.Vegetation,a key component of ecosystems,is critical in enhancing the ecological environment.The Ertix River Basin(ERB)is a transboundary watershed that spans multiple countries,mostly in arid regions.However,research on the fractional vegetation coverage(FVC)and its driving factors in the ERB remains limited.Investigating the spatiotemporal changes in the FVC and its relationship with various factors in the ERB can offer scientific support for optimizing regional vegetation restoration policies and promoting the coordinated development of human-environment interactions.The Moderate-resolution Imaging Spectroradiometer(MODIS)MYD13Q1 V6 data were obtained via the Google Earth Engine platform,and methods including the pixel dichotomy method,Theil-Sen median trend analysis,and Mann‒Kendall test were employed to examine the spatiotemporal dynamics of the FVC in the ERB from 2003 to 2023,with future trend forecast using the Hurst index.The impacts of natural and socioeconomic factors on the FVC were evaluated through the partial least squares-structural equation model(PLS-SEM).The results indicated that the FVC in the ERB showed a slight degradation trend with an average annual decrease of 0.046%during 2003-2023,with significant changes occurring in 2004,2010,and 2019.Spatially,53.380%of the study area was degraded,and the change in the FVC increased gradually from southeast to northwest.The FVC in 63.000%of the study area was highly stable and displayed long-term persistence;and the direct impact of natural factors(path coefficient of 0.617)on the FVC was significantly higher than that of socioeconomic factors(0.167).Among the natural factors,precipitation(0.999)was the most significant.This study reveals the significant impacts of natural and socioeconomic factors on vegetation dynamics in arid regions,and provides a scientific basis for transnational ecological conservation.展开更多
Energy limitation of traditional Wireless Sensor Networks(WSNs)greatly confines the network lifetime due to generating and processing massive sensing data with a limited battery.The energy harvesting WSN is a novel ne...Energy limitation of traditional Wireless Sensor Networks(WSNs)greatly confines the network lifetime due to generating and processing massive sensing data with a limited battery.The energy harvesting WSN is a novel network architecture to address the limitation of traditional WSN.However,existing coverage and deployment schemes neglect the environmental correlation of sensor nodes and external energy with respect to physical space.Comprehensively considering the spatial correlation of the environment and the uneven distribution of energy in energy harvesting WSN,we investigate how to deploy a collection of sensor nodes to save the deployment cost while ensuring the target perpetual coverage.The Confident Information Coverage(CIC)model is adopted to formulate the CIC Minimum Deployment Cost Target Perpetual Coverage(CICMTP)problem to minimize the deployed sensor nodes.As the CICMTP is NP-hard,we devise two approximation algorithms named Local Greedy Threshold Algorithm based on CIC(LGTA-CIC)and Overall Greedy Search Algorithm based on CIC(OGSA-CIC).The LGTA-CIC has a low time complexity and the OGSA-CIC has a better approximation rate.Extensive simulation results demonstrate that the OGSA-CIC is able to achieve lower deployment cost and the performance of the proposed algorithms outperforms GRNP,TPNP and EENP algorithms.展开更多
Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm ...Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm is proposed for the urban rescue search or military search in outdoor environment.Due to flexible control of small UAVs, it can be considered that all UAVs fly at the same altitude, that is, they perform search tasks on a two-dimensional plane. Based on the agents’ motion characteristics and environmental information, a mathematical model of CCPP problem is established. The minimum time for UAVs to complete the CCPP is the objective function, and complete coverage constraint, no-fly constraint, collision avoidance constraint, and communication constraint are considered. Four motion strategies and two communication strategies are designed. Then a distributed CCPP algorithm is designed based on hybrid strategies. Simulation results compared with patternbased genetic algorithm(PBGA) and random search method show that the proposed method has stronger real-time performance and better scalability and can complete the complete CCPP task more efficiently and stably.展开更多
Charismatic species are often reported by the media,providing information for detecting population status and public perception.To identify the number and distribution of free-living Black Swan(Cygnus atratus),a chari...Charismatic species are often reported by the media,providing information for detecting population status and public perception.To identify the number and distribution of free-living Black Swan(Cygnus atratus),a charismatic alien species in Chinese mainland and to detect the public and the media attitudes to the species,we analyzed the reports and emotional tendency from media coverage in 2000-2022 using manual reading,crawler extraction and latent Dirichlet allocation.A total of 6654 Black Swans were reported at 711 sites,including 147 individuals at 30 nature reserves.Successful breeding was reported at one-fourth of the total sites,including five nature reserves.The proportion of positive emotional tendency to Black Swans was overwhelming in the reports and was higher than that to alien species in general,suggesting that the public and the media are unaware of the risk of biological invasion.Effective management of invasive species requires the media clarifies the invasion risk of charismatic alien species.Promoting the unity between the harmfulness of abstract concept of alien species and the charisma of a specific alien species among the public help effective management.展开更多
In recent years,frequent fire disasters have led to enormous damage in China.Effective firefighting rescues can minimize the losses caused by fires.During the rescue processes,the travel time of fire trucks can be sev...In recent years,frequent fire disasters have led to enormous damage in China.Effective firefighting rescues can minimize the losses caused by fires.During the rescue processes,the travel time of fire trucks can be severely affected by traffic conditions,changing the effective coverage of fire stations.However,it is still challenging to determine the effective coverage of fire stations considering dynamic traffic conditions.This paper addresses this issue by combining the traveling time calculationmodelwith the effective coverage simulationmodel.In addition,it proposes a new index of total effective coverage area(TECA)based on the time-weighted average of the effective coverage area(ECA)to evaluate the urban fire services.It also selects China as the case study to validate the feasibility of the models,a fire station(FS-JX)in Changsha.FS-JX station and its surrounding 9,117 fire risk points are selected as the fire service supply and demand points,respectively.A total of 196 simulation scenarios throughout a consecutiveweek are analyzed.Eventually,1,933,815 sets of valid sample data are obtained.The results showed that the TECA of FS-JX is 3.27 km^(2),which is far below the standard requirement of 7.00 km^(2) due to the traffic conditions.The visualization results showed that three rivers around FS-JX interrupt the continuity of its effective coverage.The proposed method can provide data support to optimize the locations of fire stations by accurately and dynamically determining the effective coverage of fire stations.展开更多
The electrocatalytic conversion of CO_(2) into valuable chemical feedstocks using renewable electricity offers a compelling strategy for closing the carbon loop.While copper-based materials are effective in catalyzing...The electrocatalytic conversion of CO_(2) into valuable chemical feedstocks using renewable electricity offers a compelling strategy for closing the carbon loop.While copper-based materials are effective in catalyzing CO_(2) to C_(2+)products,the instability of Cu^(+)species,which tend to reduce to Cu~0 at cathodic potentials during CO_(2) reduction,poses a significant challenge.Here,we report the development of SmCu_(2)O and investigate the influence of f-d orbital hybridization on the CO_(2) reduction reaction (CO_(2)RR).Supported by density functional theory (DFT) calculations,our experimental results demonstrate that hybridization between Sm^(3+)4f and Cu^(+)3d orbitals not only improves the adsorption of *CO intermediates and increases CO coverage to stabilize Cu^(+) but also facilitates CO_(2) activation and lowers the energy barriers for CAC coupling.Notably,Sm-Cu_(2)O achieves a Faradaic efficiency for C_(2)H_(4) that is 38%higher than that of undoped Cu_(2)O.Additionally,it sustains its catalytic activity over an extended operational period exceeding 7 h,compared to merely 2 h for the undoped sample.This research highlights the potential of fd orbital hybridization in enhancing the efficacy of copper-based catalysts for CO_(2)RR,pointing towards a promising direction for the development of durable,high-performance electrocatalysts for sustainable chemical synthesis.展开更多
文摘Background:Globally,the use of community pharmacies and pharmacists in the delivery of vaccination services has been hampered by several factors,laws,and regulations that do not support pharmacists to participate in the delivery of vaccination services.With the advent of COVID-19 pandemic,many countries have included community pharmacists and pharmacies in vaccination services to improve coverage.This study described the delivery of vaccination services in community pharmacies using the COVID-19 experience and how their involvement impacted vaccination coverage in Nigeria.It also exposed how this experience can be used to support policy revisions to formally recognize pharmacists in immunization delivery.Methods:A descriptive cross-sectional study was conducted among 474 community pharmacists in two southwestern States in Nigeria,using a semi-structured questionnaire.It determines the number of community pharmacists who have been trained in the delivery of vaccination services,the types of vaccination services provided,and vaccines administered in their pharmacies.Data were analyzed with descriptive and inferential statistics and p-value at≤0.05.Results:Response rate was 86.7%.Less than half of the respondents(40.1%)had undergone vaccination training.Of the 129(31.4%)respondents that provide vaccination services,72(55.8%)administer vaccines in their pharmacies.Out of these 72 respondents;45(62.5%)were administering vaccines before their involvement in COVID-19 vaccine administration;57(79.2%)of the health personnel who administer vaccines were pharmacists;60(83.3%)of them administer vaccines on request;22(30.6%)administered COVID-19 vaccines only;and only 7(9.7%)of the respondents had administered over 500 doses of COVID-19 vaccines.Training in vaccination was associated with the vaccination services provided(p<0.05).Respondents suggested government support through legal framework and policy review,training and empowering pharmacists in vaccine administration,and recognition of community pharmacists as PHC providers.
基金supported by the Chinese Association of Preventive Medicine-Vaccine and Immunization Youth Talent Support Project(CPMAQT-YM0314)。
文摘Influenza is a significant global public health challenge,with seasonal epidemics imposing substantial burdens on healthcare systems and vulnerable populations,causing 3 to 5 million severe cases and 290,000 to 650,000 respiratory-related deaths worldwide each year[1].Vaccines are an effective means of preventing influenza.In recent years,China has made progress in vaccine development and immunization strategies.The population is recommended to receive influenza vaccines annually;however,their coverage remain suboptimal[2].The World Health Organization(WHO)highlights that all countries should consider implementing seasonal influenza immunization programs,with priority groups determined based on local epidemiological contexts.In alignment with the Immunization Agenda 2030,the use of seasonal influenza vaccines contributes to strengthening the life course of immunization and serves as a critical component for addressing influenza pandemics,as outlined in the WHO Global Influenza Strategy 2019-2030.
基金supported in part by the National Natural Science Foundation of China under Grants 62071189,62201220 and 62171189by the Key Research and Development Program of Hubei Province under Grant 2021BAA026 and 2020BAB120。
文摘As the problem of surface garbage pollution becomes more serious,it is necessary to improve the efficiency of garbage inspection and picking rather than traditional manual methods.Due to lightness,Unmanned Aerial Vehicles(UAVs)can traverse the entire water surface in a short time through their flight field of view.In addition,Unmanned Surface Vessels(USVs)can provide battery replacement and pick up garbage.In this paper,we innovatively establish a system framework for the collaboration between UAV and USVs,and develop an automatic water cleaning strategy.First,on the basis of the partition principle,we propose a collaborative coverage path algorithm based on UAV off-site takeoff and landing to achieve global inspection.Second,we design a task scheduling and assignment algorithm for USVs to balance the garbage loads based on the particle swarm optimization algorithm.Finally,based on the swarm intelligence algorithm,we also design an autonomous obstacle avoidance path planning algorithm for USVs to realize autonomous navigation and collaborative cleaning.The system can simultaneously perform inspection and clearance tasks under certain constraints.The simulation results show that the proposed algorithms have higher generality and flexibility while effectively improving computational efficiency and reducing actual cleaning costs compared with other schemes.
文摘Objective:To assess the complete vaccination coverage and timeliness of childhood vaccinations among Indigenous children in Peninsular Malaysia.Methods:The study utilized data from the 2022 Orang Asli Health Survey,a cross-sectional survey conducted among a representative sample of Orang Asli in Peninsular Malaysia.A total of 68 villages were randomly selected from a pool of 853 villages,encompassing diverse geographic and sociodemographic contexts with a total of 15950 respondents Orang Asli successfully interviewed.However,this study only utilized data from surveyed children aged 12 to 59 months with a total of 1551 children included.Validated structured questionnaires were used to collect sociodemographic data and health status,with nurses verifying vaccination records.Children who received all nine primary vaccinations were defined as having complete vaccination while those who received vaccine within the recommended time were defined as having timely vaccination.Data analysis was conducted using IBM SPSS version 25.0,focusing on descriptive analyses of children's vaccination status.Results:The prevalence of overall complete vaccination among Indigenous children was 87.7%,while timely vaccination was only 40.3%.The prevalence of complete vaccination for Bacillus Calmette-Guérin(BCG),the first dose of hepatitis B,three doses of DTaP-IPV-Hib,and measles,mumps,and rubella(MMR)was above 95.0%,except for the second and third doses of hepatitis B.The prevalence of timely vaccination ranged from above 95.0%for vaccines given at birth,gradually decreasing with increasing age to 57.5%for the first dose of MMR.Moreover,the completion rates for three doses of DtaP-IPV-Hib and the initial dose of MMR surpassed 90%among Indigenous children aged 12-23 months,yet the timeliness remained at a moderate level.Conclusions:While the overall complete vaccination coverage among Indigenous children in Malaysia is relatively high,there are concerning disparities in the timeliness of vaccination,particularly as children age.
基金supported by the National Natural Science Foundation of China(Grant No.42276001)2024 Qinhuangdao Social Science Development Research Project(Grant No.2024LX206)Hebei Agricultural University Research Project for Talented scholars(Grant No.YJ201835).
文摘Research has shown considerable variability in whitecap coverage(W)under low to moderate wind conditions.During an expedition to the Northwestern Pacific,oceanographic variables and photographic measurements were collected to investigate the influence of wave-induced stress on W within these wind ranges.The friction velocity was recalculated based on turbulent stress,and wind profiles were modified to account for wave-induced stress and swell presence on the sea surface.The study examined W’s relationship with multiple parameters,including friction velocity(u*),breaking wave Reynolds numbers,wavesea Reynolds numbers,and wave age.The analysis utilized both conventional u*and turbulent stress-based friction velocity(u*turb).When utilizing u*turb rather than u*,the estimation model’s fitting results revealed an increase in correlation coefficient(R2)from 0.51 to 0.62,and a decrease in root mean square error(RMSE)from 0.0652 to 0.0574.Additionally,when parameterizing W using the windsea Reynolds number,with u_(*turb) replacing u*and wind wave height substituting mixed wave height,the R^(2) increased from 0.38 to 0.53,and the RMSE decreased from 0.0737 to 0.0668.The results demonstrate that calculating u*using the turbulent stress-based method,along with wind wave height and peak wave speed of mixed waves,yields stronger correlation with W.This correlation improvement stems from the inhibition of wave breaking by swell and wave-induced stress.The integration of turbulent stress and wind wave field measurements enhances the understanding of relationships between W and various parameters.However,swell effects on wind profiles do not substantially affect W estimation using wind speed-related parameters.
基金National Natural Science Foundation of China(Grant No.52472417)to provide fund for conducting experiments.
文摘Complex multi-area collaborative coverage path planning in dynamic environments poses a significant challenge for multi-fixed-wing UAVs(multi-UAV).This study establishes a comprehensive framework that incorporates UAV capabilities,terrain,complex areas,and mission dynamics.A novel dynamic collaborative path planning algorithm is introduced,designed to ensure complete coverage of designated areas.This algorithm meticulously optimizes the operation,entry,and transition paths for each UAV,while also establishing evaluation metrics to refine coverage sequences for each area.Additionally,a three-dimensional path is computed utilizing an altitude descent method,effectively integrating twodimensional coverage paths with altitude constraints.The efficacy of the proposed approach is validated through digital simulations and mixed-reality semi-physical experiments across a variety of dynamic scenarios,including both single-area and multi-area coverage by multi-UAV.Results show that the coverage paths generated by this method significantly reduce both computation time and path length,providing a reliable solution for dynamic multi-UAV mission planning in semi-physical environments.
文摘In the current era of intelligent technologies,comprehensive and precise regional coverage path planning is critical for tasks such as environmental monitoring,emergency rescue,and agricultural plant protection.Owing to their exceptional flexibility and rapid deployment capabilities,unmanned aerial vehicles(UAVs)have emerged as the ideal platforms for accomplishing these tasks.This study proposes a swarm A^(*)-guided Deep Q-Network(SADQN)algorithm to address the coverage path planning(CPP)problem for UAV swarms in complex environments.Firstly,to overcome the dependency of traditional modeling methods on regular terrain environments,this study proposes an improved cellular decomposition method for map discretization.Simultaneously,a distributed UAV swarm system architecture is adopted,which,through the integration of multi-scale maps,addresses the issues of redundant operations and flight conflicts inmulti-UAV cooperative coverage.Secondly,the heuristic mechanism of the A^(*)algorithmis combinedwith full-coverage path planning,and this approach is incorporated at the initial stage ofDeep Q-Network(DQN)algorithm training to provide effective guidance in action selection,thereby accelerating convergence.Additionally,a prioritized experience replay mechanism is introduced to further enhance the coverage performance of the algorithm.To evaluate the efficacy of the proposed algorithm,simulation experiments were conducted in several irregular environments and compared with several popular algorithms.Simulation results show that the SADQNalgorithmoutperforms othermethods,achieving performance comparable to that of the baseline prior algorithm,with an average coverage efficiency exceeding 2.6 and fewer turning maneuvers.In addition,the algorithm demonstrates excellent generalization ability,enabling it to adapt to different environments.
文摘Published proof test coverage(PTC)estimates for emergency shutdown valves(ESDVs)show only moderate agreement and are predominantly opinion-based.A Failure Modes,Effects,and Diagnostics Analysis(FMEDA)was undertaken using component failure rate data to predict PTC for a full stroke test and a partial stroke test.Given the subjective and uncertain aspects of the FMEDA approach,specifically the selection of component failure rates and the determination of the probability of detecting failure modes,a Fuzzy Inference System(FIS)was proposed to manage the data,addressing the inherent uncertainties.Fuzzy inference systems have been used previously for various FMEA type assessments,but this is the first time an FIS has been employed for use with FMEDA.ESDV PTC values were generated from both the standard FMEDA and the fuzzy-FMEDA approaches using data provided by FMEDA experts.This work demonstrates that fuzzy inference systems can address the subjectivity inherent in FMEDA data,enabling reliable estimates of ESDV proof test coverage for both full and partial stroke tests.This facilitates optimized maintenance planning while ensuring safety is not compromised.
文摘This study utilized a computer application developed in Visual StudioTM using C# to extract pixel samples (RGB) from multiple images (26 images obtained from August 20, 2024, to September 22, 2024), of a purslane pot taken from a top-down perspective at a distance of 30 cm. These samples were projected into the CIELAB color space, and the extracted pixels were plotted on the a*b* plane, excluding the luminance value. A polygon was then drawn around all the plotted pixels, defining the color to be identified. Subsequently, the application analyzed another image to determine the number of pixels within the polygon. These identified pixels were transformed to white, and the percentage of these pixels relative to the total number of pixels in the image was calculated. This process yielded percentages for brown (soil), green (leaf cover), and pink (stem color). A single polygon was sufficient to accurately identify the green and brown colors in the images. However, due to varying lighting conditions, customized polygons were necessary for each image to accurately identify the stem color. To validate the green polygon’s accuracy in identifying purslane leaves, all leaves in the image were digitized in AutoCADTM, and the green area was compared to the total image area to obtain the observed green percentage. The green percentage obtained with the polygon was then compared to the observed green percentage, resulting in an R2 value of 0.8431. Similarly, for the brown color, an R2 value of 0.9305 was found. The stem color was not subjected to this validation due to the necessity of multiple polygons. The R2 values were derived from percentage data obtained by analyzing the total pixels in the images. When sampling to estimate the proportion and analyzing only the suggested sample size of pixels, R2 values of 0.93049 for brown and 0.8088 for green were obtained. The average analysis time to determine the brown soil percentage using the polygon (BP) for 26 images with an average size of 1070 × 1210 pixels was 44 seconds. In contrast, sampling to estimate the proportion reduced the analysis time to 0.9 seconds for the same number of images. This indicates that significant time savings can be achieved while obtaining similar results.
基金Feng Wei was supported by the National Natural Science Foundation of China under Grant 62425110.
文摘This paper proposes a novel blended hyper-cellular architecture for low-altitude aerial intelligent networks(LAINs)to provide agile coverage tailored to active air routes and takeoff/landing spots.Traditional cellular networks struggle to meet the dynamic demands of low-altitude UAV communications due to their rigid structures.The hyper-cellular network(HCN)architecture separates control and traffic coverage,enabling flexible and energy-efficient operations.The key components include control base stations(CBSs)for wide-area signaling coverage and traffic base stations(TBSs)that can be dynamically activated based on traffic demands.The proposed solution also integrates space information networks(SINs)to enhance the coverage efficiency.Key technologies such as all-G CBS using RISC-V architecture,AI-powered radio maps for low-altitude environments,and agile TBS coverage adaptation are introduced with some preliminary studies.These designs aim to address challenges like mobility management,interference coordination,and the need for real-time spectrum sharing in blended satellite-terrestrial networks.The proposed solution offers a scalable and agile framework to support the rapidly growing demand for reliable,low-latency,and high-capacity UAV communications in urban environments.
基金supported by the National Key Research and Development Program of China under Grant 2018YFA0701601by the Program of Jiangsu Province under Grant NTACT-2024-Z-001.
文摘In offshore maritime communication sys-tems,base stations(BSs)are employed along the coastline to provide high-speed data service for ves-sels in coastal sea areas.To ensure the line-of-sight propagation of BS-vessel links,high transceiver an-tenna height is required,which limits the number of geographically available sites for BS deployment,and imposes a high cost for realizing effective wide-area coverage.In this paper,the joint user association and power allocation(JUAPA)problem is investigated to enhance the coverage of offshore maritime systems.By exploiting the characteristics of network topology as well as vessels’motion in offshore communica-tions,a multi-period JUAPA problem is formulated to maximize the number of ships that can be simultane-ously served by the network.This JUAPA problem is intrinsically non-convex and subject to mixed-integer constraints,which is difficult to solve either analyt-ically or numerically.Hence,we propose an iterative augmentation based framework to efficiently select the active vessels,where the JUAPA scheme is iteratively optimized by the network for increasing the number of the selected vessels.More specifically,in each itera-tion,the user association variables and power alloca-tion variables are determined by solving two separate subproblems,so that the JUAPA strategy can be up-dated in a low-complexity manner.The performance of the proposed JUAPA method is evaluated by exten-sive simulation,and numerical results indicate that it can effectively increase the number of vessels served by the network,and thus enhances the coverage of off-shore systems.
文摘A thoroughly mechanistic understanding of the electrochemical CO reduction reaction(eCORR)at the interface is significant for guiding the design of high-performance electrocatalysts.However,unintentionally ignored factors or unreasonable settings during mechanism simulations will result in false positive results between theory and experiment.Herein,we computationally identified the dynamic site preference change of CO adsorption with potentials on Cu(100),which was a previously unnoticed factor but significant to potential-dependent mechanistic studies.Combined with the different lateral interactions among adsorbates,we proposed a new C–C coupling mechanism on Cu(100),better explaining the product distribution at different potentials in experimental eCORR.At low potentials(from–0.4 to–0.6 V_(RHE)),the CO forms dominant adsorption on the bridge site,which couples with another attractively aggregated CO to form a C–C bond.At medium potentials(from–0.6 to–0.8 VRHE),the hollow-bound CO becomes dominant but tends to isolate with another adsorbate due to the repulsion,thereby blocking the coupling process.At high potentials(above–0.8 VRHE),the CHO intermediate is produced from the electroreduction of hollow-CO and favors the attraction with another bridge-CO to trigger C–C coupling,making CHO the major common intermediate for C–C bond formation and methane production.We anticipate that our computationally identified dynamic change in site preference of adsorbates with potentials will bring new opportunities for a better understanding of the potential-dependent electrochemical processes.
基金supported by the National Natural Science Foundation of China(42171109,32130068)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2020237)National Key R&D Program of China(2023YFF1304604).
文摘Urban vegetation plays a crucial role in regulating temperatures and heat waves in urban areas.However,the influence of vegetation coverage and its configuration on surface temperatures in different climate zones at a national scale is unclear.To address this,we utilized high-resolution data to detect spatial patterns for 31 provincial capital cities in China.We integrated day and night surface temperatures to determine the influence of vegetative coverage and configuration on urban temperatures across different climate zones and city sizes.Our study revealed that a subtropical monsoon climate and medium-sized cities had the highest vegetative coverage and shape complexity.The best connectivity and agglomeration of vegetation were found in a temperate monsoon climate and large cities.In contrast,small cities,especially those under a temperate continental climate,had low vegetation coverage,high fragmentation,and weak agglomeration and connectivity.In addition,vegetative coverage had a negative impact on daytime surface temperatures,especially in large cities in a subtropical monsoon climate.However,an increase in vegetation coverage could result in warming at night in small cities in temperate continental climates.Although urban vegetation configuration also contributed to moderating surface temperatures,especially at night,they did not surpass the influence of vegetation coverage.The effect on nighttime temperatures of the configuration of vegetation increased by 3–6%relative to that of daytime temperatures,especially in large cities in a temperate monsoon climate.The contribution vegetation coverage and configuration interaction to cooling efficiency decreased at night,especially in medium-sized cities in a temperate continental climate by 3–5%.In addition,this study identified several moderating effects of natural and social factors on the relationship between urban vegetation coverage and surface temperatures.High duration of sunshine,low humidity and high wind speed significantly enhanced the negative impact of vegetation coverage on surface temperatures.In addition,the moderating effect of vegetation coverage was more pronounced in low population density cities and high gross domestic product.This study enhances understanding of the ecological functions of urban vegetation and provides a valuable scientific basis and strategic recommendations for optimizing urban vegetation and improving urban environmental quality.
基金funded by the Third Xinjiang Comprehensive Scientific Investigation Project,China(2022xjkk0702)the Western Young Scholars Project of the Chinese Academy of Sciences(2022-XBQNXZ-001)the Tianshan Talent Development Program,China(2022TSYCCX0006).
文摘The rapid acceleration of global warming and intensifying human activities have exacerbated the fragility and climate sensitivity of ecosystems worldwide,particularly in arid regions.Vegetation,a key component of ecosystems,is critical in enhancing the ecological environment.The Ertix River Basin(ERB)is a transboundary watershed that spans multiple countries,mostly in arid regions.However,research on the fractional vegetation coverage(FVC)and its driving factors in the ERB remains limited.Investigating the spatiotemporal changes in the FVC and its relationship with various factors in the ERB can offer scientific support for optimizing regional vegetation restoration policies and promoting the coordinated development of human-environment interactions.The Moderate-resolution Imaging Spectroradiometer(MODIS)MYD13Q1 V6 data were obtained via the Google Earth Engine platform,and methods including the pixel dichotomy method,Theil-Sen median trend analysis,and Mann‒Kendall test were employed to examine the spatiotemporal dynamics of the FVC in the ERB from 2003 to 2023,with future trend forecast using the Hurst index.The impacts of natural and socioeconomic factors on the FVC were evaluated through the partial least squares-structural equation model(PLS-SEM).The results indicated that the FVC in the ERB showed a slight degradation trend with an average annual decrease of 0.046%during 2003-2023,with significant changes occurring in 2004,2010,and 2019.Spatially,53.380%of the study area was degraded,and the change in the FVC increased gradually from southeast to northwest.The FVC in 63.000%of the study area was highly stable and displayed long-term persistence;and the direct impact of natural factors(path coefficient of 0.617)on the FVC was significantly higher than that of socioeconomic factors(0.167).Among the natural factors,precipitation(0.999)was the most significant.This study reveals the significant impacts of natural and socioeconomic factors on vegetation dynamics in arid regions,and provides a scientific basis for transnational ecological conservation.
基金supported by National Natural Science Foundation of China(Grant No.61871209,No.62272182 and No.61901210)Shenzhen Science and Technology Program under Grant JCYJ20220530161004009+2 种基金Natural Science Foundation of Hubei Province(Grant No.2022CF011)Wuhan Business University Doctoral Fundamental Research Funds(Grant No.2021KB005)in part by Artificial Intelligence and Intelligent Transportation Joint Technical Center of HUST and Hubei Chutian Intelligent Transportation Co.,LTD under project Intelligent Tunnel Integrated Monitoring and Management System.
文摘Energy limitation of traditional Wireless Sensor Networks(WSNs)greatly confines the network lifetime due to generating and processing massive sensing data with a limited battery.The energy harvesting WSN is a novel network architecture to address the limitation of traditional WSN.However,existing coverage and deployment schemes neglect the environmental correlation of sensor nodes and external energy with respect to physical space.Comprehensively considering the spatial correlation of the environment and the uneven distribution of energy in energy harvesting WSN,we investigate how to deploy a collection of sensor nodes to save the deployment cost while ensuring the target perpetual coverage.The Confident Information Coverage(CIC)model is adopted to formulate the CIC Minimum Deployment Cost Target Perpetual Coverage(CICMTP)problem to minimize the deployed sensor nodes.As the CICMTP is NP-hard,we devise two approximation algorithms named Local Greedy Threshold Algorithm based on CIC(LGTA-CIC)and Overall Greedy Search Algorithm based on CIC(OGSA-CIC).The LGTA-CIC has a low time complexity and the OGSA-CIC has a better approximation rate.Extensive simulation results demonstrate that the OGSA-CIC is able to achieve lower deployment cost and the performance of the proposed algorithms outperforms GRNP,TPNP and EENP algorithms.
基金supported by the National Natural Science Foundation of China (61903036, 61822304)Shanghai Municipal Science and Technology Major Project (2021SHZDZX0100)。
文摘Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm is proposed for the urban rescue search or military search in outdoor environment.Due to flexible control of small UAVs, it can be considered that all UAVs fly at the same altitude, that is, they perform search tasks on a two-dimensional plane. Based on the agents’ motion characteristics and environmental information, a mathematical model of CCPP problem is established. The minimum time for UAVs to complete the CCPP is the objective function, and complete coverage constraint, no-fly constraint, collision avoidance constraint, and communication constraint are considered. Four motion strategies and two communication strategies are designed. Then a distributed CCPP algorithm is designed based on hybrid strategies. Simulation results compared with patternbased genetic algorithm(PBGA) and random search method show that the proposed method has stronger real-time performance and better scalability and can complete the complete CCPP task more efficiently and stably.
基金financially supported by the National Key Research and Development Program of China(Number 2022YFC2601100)。
文摘Charismatic species are often reported by the media,providing information for detecting population status and public perception.To identify the number and distribution of free-living Black Swan(Cygnus atratus),a charismatic alien species in Chinese mainland and to detect the public and the media attitudes to the species,we analyzed the reports and emotional tendency from media coverage in 2000-2022 using manual reading,crawler extraction and latent Dirichlet allocation.A total of 6654 Black Swans were reported at 711 sites,including 147 individuals at 30 nature reserves.Successful breeding was reported at one-fourth of the total sites,including five nature reserves.The proportion of positive emotional tendency to Black Swans was overwhelming in the reports and was higher than that to alien species in general,suggesting that the public and the media are unaware of the risk of biological invasion.Effective management of invasive species requires the media clarifies the invasion risk of charismatic alien species.Promoting the unity between the harmfulness of abstract concept of alien species and the charisma of a specific alien species among the public help effective management.
基金supported by National Key R&D Program of China under Grants No.2022YFB4400703National Natural Science Foundation of Heilongjiang Province of China(Outstanding Youth Foundation)under Grants No.JJ2019YX0922 and NSFC under Grants No.F2018006.
基金support from the National Natural Science Foundation of China (No.52204202)the Hunan Provincial Natural Science Foundation of China (No.2023JJ40058)the Science and Technology Program of Hunan Provincial Departent of Transportation (No.202122).
文摘In recent years,frequent fire disasters have led to enormous damage in China.Effective firefighting rescues can minimize the losses caused by fires.During the rescue processes,the travel time of fire trucks can be severely affected by traffic conditions,changing the effective coverage of fire stations.However,it is still challenging to determine the effective coverage of fire stations considering dynamic traffic conditions.This paper addresses this issue by combining the traveling time calculationmodelwith the effective coverage simulationmodel.In addition,it proposes a new index of total effective coverage area(TECA)based on the time-weighted average of the effective coverage area(ECA)to evaluate the urban fire services.It also selects China as the case study to validate the feasibility of the models,a fire station(FS-JX)in Changsha.FS-JX station and its surrounding 9,117 fire risk points are selected as the fire service supply and demand points,respectively.A total of 196 simulation scenarios throughout a consecutiveweek are analyzed.Eventually,1,933,815 sets of valid sample data are obtained.The results showed that the TECA of FS-JX is 3.27 km^(2),which is far below the standard requirement of 7.00 km^(2) due to the traffic conditions.The visualization results showed that three rivers around FS-JX interrupt the continuity of its effective coverage.The proposed method can provide data support to optimize the locations of fire stations by accurately and dynamically determining the effective coverage of fire stations.
基金Financial support from the National Natural Science Foundation of China(grant nos.22379006,21575016,U20A20154,22279005)from the National Program for Support of Top-notch Young Professionals is gratefully acknowledged。
文摘The electrocatalytic conversion of CO_(2) into valuable chemical feedstocks using renewable electricity offers a compelling strategy for closing the carbon loop.While copper-based materials are effective in catalyzing CO_(2) to C_(2+)products,the instability of Cu^(+)species,which tend to reduce to Cu~0 at cathodic potentials during CO_(2) reduction,poses a significant challenge.Here,we report the development of SmCu_(2)O and investigate the influence of f-d orbital hybridization on the CO_(2) reduction reaction (CO_(2)RR).Supported by density functional theory (DFT) calculations,our experimental results demonstrate that hybridization between Sm^(3+)4f and Cu^(+)3d orbitals not only improves the adsorption of *CO intermediates and increases CO coverage to stabilize Cu^(+) but also facilitates CO_(2) activation and lowers the energy barriers for CAC coupling.Notably,Sm-Cu_(2)O achieves a Faradaic efficiency for C_(2)H_(4) that is 38%higher than that of undoped Cu_(2)O.Additionally,it sustains its catalytic activity over an extended operational period exceeding 7 h,compared to merely 2 h for the undoped sample.This research highlights the potential of fd orbital hybridization in enhancing the efficacy of copper-based catalysts for CO_(2)RR,pointing towards a promising direction for the development of durable,high-performance electrocatalysts for sustainable chemical synthesis.
