Due to the lack of accurate data and complex parameterization,the prediction of groundwater depth is a chal-lenge for numerical models.Machine learning can effectively solve this issue and has been proven useful in th...Due to the lack of accurate data and complex parameterization,the prediction of groundwater depth is a chal-lenge for numerical models.Machine learning can effectively solve this issue and has been proven useful in the prediction of groundwater depth in many areas.In this study,two new models are applied to the prediction of groundwater depth in the Ningxia area,China.The two models combine the improved dung beetle optimizer(DBO)algorithm with two deep learning models:The Multi-head Attention-Convolution Neural Network-Long Short Term Memory networks(MH-CNN-LSTM)and the Multi-head Attention-Convolution Neural Network-Gated Recurrent Unit(MH-CNN-GRU).The models with DBO show better prediction performance,with larger R(correlation coefficient),RPD(residual prediction deviation),and lower RMSE(root-mean-square error).Com-pared with the models with the original DBO,the R and RPD of models with the improved DBO increase by over 1.5%,and the RMSE decreases by over 1.8%,indicating better prediction results.In addition,compared with the multiple linear regression model,a traditional statistical model,deep learning models have better prediction performance.展开更多
Forest ecosystems are important for biodiversity conservation and human societies,but are under pressure due to climate change and human interventions.This applies to natural forests as well as tree plantations.The la...Forest ecosystems are important for biodiversity conservation and human societies,but are under pressure due to climate change and human interventions.This applies to natural forests as well as tree plantations.The latter are globally widespread and therefore gaining increasing importance for biodiversity conservation.However,even after dieback due to increasing disturbance frequencies,such plantations are primarily managed for economic returns,leading to growing conflicts among stakeholders.In particular,the impact of forest management on biodiversity is being discussed.This study investigates the effects of five management approaches in a landscape severely affected by spruce(Picea abies L.)dieback on beetle diversity,conservation,and community composition.We considered direct effects of management and indirect effects of environmental parameters separately in ground-dwelling and flight-active beetles.Beetle diversity was strongly affected by forest management,with nonintervention deadwood stands being most beneficial for beetles.In addition,we show indirect effects of environmental factors.In general,parameters related to salvage logging(e.g.open canopies,tree stumps)influenced beetle diversity and conservation negatively,while positive effects were found for soil nutrient availability and plant species richness.Community composition differed strongly among management categories and indicated a lack of landscape connectivity for open habitat species,as we found only low proportions of such species even on salvage-logged sites.We propose a mixture of management approaches after bark beetle outbreaks,including a substantial proportion of non-intervention deadwood stands,to increase landscape heterogeneity and connectivity.This may increase overall biodiversity while addressing the concerns of both forestry and species conservation.展开更多
This study introduces a novel algorithm known as the dung beetle optimization algorithm based on bounded reflection optimization andmulti-strategy fusion(BFDBO),which is designed to tackle the complexities associated ...This study introduces a novel algorithm known as the dung beetle optimization algorithm based on bounded reflection optimization andmulti-strategy fusion(BFDBO),which is designed to tackle the complexities associated with multi-UAV collaborative trajectory planning in intricate battlefield environments.Initially,a collaborative planning cost function for the multi-UAV system is formulated,thereby converting the trajectory planning challenge into an optimization problem.Building on the foundational dung beetle optimization(DBO)algorithm,BFDBO incorporates three significant innovations:a boundary reflection mechanism,an adaptive mixed exploration strategy,and a dynamic multi-scale mutation strategy.These enhancements are intended to optimize the equilibrium between local exploration and global exploitation,facilitating the discovery of globally optimal trajectories thatminimize the cost function.Numerical simulations utilizing the CEC2022 benchmark function indicate that all three enhancements of BFDBOpositively influence its performance,resulting in accelerated convergence and improved optimization accuracy relative to leading optimization algorithms.In two battlefield scenarios of varying complexities,BFDBO achieved a minimum of a 39% reduction in total trajectory planning costs when compared to DBO and three other highperformance variants,while also demonstrating superior average runtime.This evidence underscores the effectiveness and applicability of BFDBO in practical,real-world contexts.展开更多
Nature-inspired designs have increasingly influenced biomedical engineering by providing superior biomechanical performance and structural stability.In this study,the diabolical ironclad beetle elytra structure was ap...Nature-inspired designs have increasingly influenced biomedical engineering by providing superior biomechanical performance and structural stability.In this study,the diabolical ironclad beetle elytra structure was applied to stent strut designs and thoroughly evaluated through various computational simulations to assess their potential to enhance the mechanical performance of WE43 magnesium alloy stents.Connected elliptical structures with a vertical-to-horizontal length ratio of 1:1.8 were incorporated in varying numbers and then compared to conventional laser-cut stents using 3-point bending,crush,crimping,and expansion tests,internal carotid artery insertion simulations,and computational fluid dynamics analyses.The results demonstrated that the biomimetic stents exhibited significantly improved stress distribution and reduced applied stress while maintaining hemodynamic stability.Computational fluid dynamics simulations further confirmed that the biomimetic could reduce wall shear stress and improve blood flow,thereby potentially minimizing the risk of restenosis and thrombosis.These findings suggest that diabolical ironclad beetle-inspired stent structures may offer enhanced biomechanical performance and clinical safety in magnesium-based endovascular interventions.展开更多
The dung beetle optimizer(DBO)is a metaheuristic algorithm with fast convergence and powerful search capabilities,which has shown excellent performance in solving various optimization problems.However,it suffers from ...The dung beetle optimizer(DBO)is a metaheuristic algorithm with fast convergence and powerful search capabilities,which has shown excellent performance in solving various optimization problems.However,it suffers from the problems of easily falling into local optimal solutions and poor convergence accuracy when dealing with large-scale complex optimization problems.Therefore,we propose an adaptive DBO(ADBO)based on an elastic annealing mechanism to address these issues.First,the convergence factor is adjusted in a nonlinear decreasing manner to balance the requirements of global exploration and local exploitation,thus improving the convergence speed and search quality.Second,a greedy difference optimization strategy is introduced to increase population diversity,improve the global search capability,and avoid premature convergence.Finally,the elastic annealing mechanism is used to perturb the randomly selected individuals,helping the algorithm escape local optima and thereby improve solution quality and algorithm stability.The experimental results on the CEC 2017 and CEC 2022 benchmark function sets and MCNC benchmark circuits verify the effectiveness,superiority,and universality of ADBO.展开更多
Any malfunctions of the actuators of the robots have the potential to destroy the robot’s normal motion,and most of the current actuator fault diagnosis methods are difficult to meet the requirements of simplifying t...Any malfunctions of the actuators of the robots have the potential to destroy the robot’s normal motion,and most of the current actuator fault diagnosis methods are difficult to meet the requirements of simplifying the actuator modeling and solving the difficulty of fault data collection.To solve the problem of real-time diagnosis of actuator faults in the 3-PR(P)S parallel robot,the model of 3-PR(P)S parallel robot and data-driven-based method for the fault diagnosis are presented.Firstly,only the input-output relationship of the actuator is considered for modeling actuator faults,reducing the complexity of fault modeling and reducing the time consumption of parameter identification,thereby meeting the requirements of real-time diagnosis.A Simulink model of the electromechanical actuator(EMA)was constructed to analyze actuator faults.Then the short-term analysis method was employed for collecting the sample data of the slider position on the test platform of the EMA system and feature extraction.Training samples for neural networks are obtained.Furthermore,we optimized the Back Propagation(BP)neural network using the Dung Beetle Optimization Algorithm(DBO),which effectively resolved the weights and thresholds of the BP neural network.Compared to BP and Particle Swarm Optimization(PSO)-BP,the DBO-BP has better convergence,convergence rate,and the best-classifying quality.So,the classification for the different actuator faults is obviously improved.Finally,a fault diagnosis system was designed for the actuator of the 3-PR(P)S parallel robot,and the experimental results demonstrate that this system can detect actuator faults within 0.1 seconds.This work also provides the technical support for the fault-tolerant control of the 3-PR(P)S Parallel robot.展开更多
Tenebrionid beetles represent a crucial arthropod taxon in the Gobi desert ecosystems owing to their species richness and high biomass,both of which are essential for maintaining ecosystem health and stability.However...Tenebrionid beetles represent a crucial arthropod taxon in the Gobi desert ecosystems owing to their species richness and high biomass,both of which are essential for maintaining ecosystem health and stability.However,the spatiotemporal variations of tenebrionid beetle assemblages in the Gobi desert remain poorly understood.In this study,the monthly dynamics of tenebrionid beetles in the central part of the Hexi Corridor,Northwest China,a representative area of the Gobi desert ecosystems,were monitored using pitfall trapping during 2015-2020.The following results were showed:(1)monthly activity of tenebrionid beetles was observed from March to October,with monthly activity peaking in spring and summer,and monthly activity periods and peak of tenebrionid beetle species exhibited interspecific differences that varied from year to year;(2)spatial distribution of tenebrionid beetle community was influenced by structural factors.Specifically,at a spatial scale of 24.00 m,tenebrionid beetle community was strongly and positively correlated with the dominant species,with distinct spatial distribution patterns observed for Blaps gobiensis and Microdera kraatzi alashanica;(3)abundance of tenebrionid beetles was positively correlated with monthly mean precipitation and monthly mean temperature,whereas monthly abundance of B.gobiensis and M.kraatzi alashanica was positively correlated with monthly mean precipitation;and(4)the cover of Reaumuria soongarica(Pall.)Maxim.and Nitraria sphaerocarpa Maxim.had a positive influence on the number of tenebrionid beetles captured.In conclusion,monthly variation in precipitation significantly influences the community dynamic of tenebrionid beetles,with precipitation and shrub cover jointly determining the spatial distribution pattern of these beetles in the Gobi desert ecosystems.展开更多
The natural composition of forests has undergone significant changes over recent centuries.A closer-to-natural tree species composition has long been perceived as key to a high biodiversity.We investigated the impact ...The natural composition of forests has undergone significant changes over recent centuries.A closer-to-natural tree species composition has long been perceived as key to a high biodiversity.We investigated the impact on communities of click beetles(Elateridae)caused by changes in the tree species composition of spruce monocultures compared to reference sites of recently unmanaged natural beech forests.To collect data,passive interception traps were distributed within managed spruce stands of different age classes and natural beech forests of various developmental stages.The beetle species richness was slightly but not significantly higher in the beech forests.The saproxylic species group was significantly more common in the spruce stands,whereas the group of nonsaproxylic species was significantly more abundant in the beech stands.In the commercial stands,the significantly highest species richness was in the clearings(0–10-year-old stands),and at this forest age class,the vast majority of the beetle species occurred in the spruce stands.In the developmental stages of the natural forest,a slightly higher beetle richness was found at the disintegration stage.The study results suggested that different tree species compositions and stand structures affect the communities of click beetles and substantially change their species composition and thus their response to external influences.Therefore,management of stands using diverse silvicultural systems is recommended for creating diverse ecological niches in forests.展开更多
Biodiversity loss is a significant problem at a global scale and may be amplified by climate change.In recent years,coniferous forests have had substantial die-back across Europe due to drought and subsequent bark-bee...Biodiversity loss is a significant problem at a global scale and may be amplified by climate change.In recent years,coniferous forests have had substantial die-back across Europe due to drought and subsequent bark-beetle outbreaks.As many studies on the consequences of disturbance and subsequent management have focused on natural stands,management implications for managed spruce stands are not well understood,even though such stands are widespread throughout Europe.In this study,beetle taxonomy,conservation value,and community com-position are compared among spruce plantations and four post-disturbance management approaches:standing dead-wood,lying deadwood,clear cuts,and long-term succession.Diversity and community composition differed significantly among management categories,while different beetle fami-lies responded similarly.Intact spruce stands harbored the lowest beetle diversity while the highest taxonomic diver-sity and conservation value was on clear cuts and stands with lying or standing deadwood.The proportion of forest specialists was highest in successional forests.In summary,different forest management categories harbored distinct beetle communities at the family-,species-,and ecological guild levels.Therefore,post-disturbance management should consider the landscape scale and include different management types.This enhances landscape heterogeneity and thus overall biodiversity but could also mitigate negative impacts of natural disturbances on ecosystem services.展开更多
To improve the flexural properties of Beetle Elytron Plates(BEPs)and clarify the effect of the transition arcs(chamfers)between the skins and the trabeculae,the chamfers were set in BEPs,and then the influence of the ...To improve the flexural properties of Beetle Elytron Plates(BEPs)and clarify the effect of the transition arcs(chamfers)between the skins and the trabeculae,the chamfers were set in BEPs,and then the influence of the chamfer on BEPs'mechanical properties was investigated via experimentation and the Finite Elemnent Method simulation(FEM).The results indicate that the influence of the chamfer on the flexural properties and ductility was most obvious in the Trabecular Beetle Elytron Plates(TBEPs),less obvious in the Honeycomb Plates(HPs)and basically no efiect was observed on End-trabecular Beetle Elytron Plates(EBEPs).The chamfer can improve the mechanical stability of EBEPSs.As the chamfer diameter increased in the BEPs,the length of the residual trabecular root on the skin increased when failure occurred in the TBEPs.The crack position in the honeycomb wallsof the HPs gradually shifted from the skin to the center.The EBEPs continued to exhibit oblique cracks.From the perspective of the force characteristics of these BEPs.combined with numerical simulation,the influence mechanism of the chamfer on their flcxural propertics was investigated.展开更多
This study investigates the dung beetle fauna in northern Pakistan, including Khyber Pakhtunkhwa province, Gilgit-Baltistan（formerly known as the Northern Areas of Pakistan）, and Federally Administered Tribal Areas,...This study investigates the dung beetle fauna in northern Pakistan, including Khyber Pakhtunkhwa province, Gilgit-Baltistan（formerly known as the Northern Areas of Pakistan）, and Federally Administered Tribal Areas, based on collections and determined specimens. The area is diverse and contains a variety of flora and fauna pertaining to different habitats. We conducted surveys in the Alpine Zone, Montane Temperate Forest and Tropical Deciduous Forest. Three genera and five species, Digitonthophagus gazelle,Digitonthophagus bonasus, Heliocopris midas, Heliocopris bucephalus and Gymnopleurus flagellates were collected. Identification keys and distribution notes are provided. Heliocopris bucephalus was found to be a new country record to Pakistan.展开更多
A scanning electron microscope was used to observe the structures of the setae on the surface of a dung beetle Copris ochus, Motschulsky. There are lots of setae on the body surface, especially on the ventral part sur...A scanning electron microscope was used to observe the structures of the setae on the surface of a dung beetle Copris ochus, Motschulsky. There are lots of setae on the body surface, especially on the ventral part surface and lateral to the legs which are different in size, arrangement and shape. These setae have different lengths and many thorns on the whole seta. The top ends of these setae stand up without furcations which direct uprightly towards the surface of the touched soil. By the method of removing these setae, getting the insect weight before and after digging into the dung we affirm farther that the setae on the beetle body surface form the anti-stick and non-adherent gentle interface. The soil machines and components made by imitating the gentle body surface of beetles have favorable non-adherent results.展开更多
Efficient collection of water from fog provides a potential solution to solve the global freshwater shortage problem, particularly in the desert or arid regions. In this work, a flexible and highly efficient fog colle...Efficient collection of water from fog provides a potential solution to solve the global freshwater shortage problem, particularly in the desert or arid regions. In this work, a flexible and highly efficient fog collector was prepared by mimicking the back exoskeleton structure of the Namib desert beetle. The improved fog collector was constructed by a superhydrophobic-superhydrophilic patterned fabric via a simple weaving method, followed by in-situ deposition of copper particles. Compared with the conventional fog collector with a plane structure, the fabric has shown a higher water-harvesting rate at 1432.7 mg/h/cm2,owing to the biomimetic three-dimensional structure, its enhanced condensation performance enabled by the copper coating and the rational distribution of wetting units. The device construction makes use of the widely available textile materials through mature manufacturing technology, which makes it highly suitable for large-scale industrial production.展开更多
In order to found new carriers of pine wood nematode(PWN),Bursaphelenchus xylophilus,beetles were collected from pine wilt disease-affected areas in six provinces in China.A total of 8830 beetles of 29 species was col...In order to found new carriers of pine wood nematode(PWN),Bursaphelenchus xylophilus,beetles were collected from pine wilt disease-affected areas in six provinces in China.A total of 8830 beetles of 29 species was collected and examined to determine whether they were PWN carriers.Eight species were identified as carriers.Results included the first worldwide report of Monochamus uigromaculatus,Semanotus siuoauster,and Uraecha angusta being carriers of PWN,and the first report from China of A rhopalus rusticus carrying PWN.Monochamus alternatus was commonly collected in all six provinces and was the dominant species in four inland affected areas and A.rusticus was dominant in two coastal affected areas.The species varied between different neighboring regions in the same province.The distribution of the same species varied considerably over different regions.展开更多
AIM To determine short-and long-term outcomes of endoscopic submucosal dissection(ESD) using the stag beetle(SB) knife, a scissor-shaped device.METHODS Seventy consecutive patients with 96 early esophageal neoplasms, ...AIM To determine short-and long-term outcomes of endoscopic submucosal dissection(ESD) using the stag beetle(SB) knife, a scissor-shaped device.METHODS Seventy consecutive patients with 96 early esophageal neoplasms, who underwent ESD using a SB knife at Kure Medical Center and Chugoku Cancer Center, Japan, between April 2010 and August 2016, were retrospectively evaluated. Clinicopathological characteristics of lesions and procedural adverse events were assessed. Therapeutic success was evaluated on the basis of en bloc, histologically complete, and curative or non-curative resection rates. Overall and tumor-specific survival, local or distant recurrence, and 3-and 5-year cumulative overall metachronous cancer rates were also assessed.RESULTS Eligible patients had dysplasia/intraepithelial neoplasia(22%) or early cancers(squamous cell carcinoma, 78%). The median procedural time was 60 min and on average, the lesions measured 24 mm in diameter, yielding 33-mm tissue defects. The en bloc resection rate was 100%, with 95% and 81% of dissections deemed histologically complete and curative, respectively. All procedures were completed without accidental incisions/perforations or delayed bleeding. During follow-up(mean, 35 ± 23 mo), no local recurrences or metastases were observed. The 3-and 5-year survival rates were 83% and 70%, respectively, with corresponding rates of 85% and 75% for curative resections and 74% and 49% for noncurative resections. The 3-and 5-year cumulative rates of metachronous cancer in the patients with curative resections were 14% and 26%, respectively.CONCLUSION ESD procedures using the SB knife are feasible, safe, and effective for treating early esophageal neoplasms, yielding favorable short-and long-term outcomes.展开更多
In the process of Wavelet Analysis,only the low-frequency signals are re-decomposed,and the high-frequency signals are no longer decomposed,resulting in a decrease in frequency resolution with increasing frequency.The...In the process of Wavelet Analysis,only the low-frequency signals are re-decomposed,and the high-frequency signals are no longer decomposed,resulting in a decrease in frequency resolution with increasing frequency.Therefore,in this paper,firstly,Wavelet Packet Decomposition is used for feature extraction of vibration signals,which makes up for the shortcomings of Wavelet Analysis in extracting fault features of nonlinear vibration signals,and different energy values in different frequency bands are obtained by Wavelet Packet Decomposition.The features are visualized by the K-Means clustering method,and the results show that the extracted energy features can accurately distinguish the different states of the bearing.Then a fault diagnosis model based on BP Neural Network optimized by Beetle Algo-rithm is proposed to identify the bearing faults.Compared with the Particle Swarm Algorithm,Beetle Algorithm can quickly find the error extreme value,which greatly reduces the training time of the model.At last,two experiments are conducted,which show that the accuracy of the model can reach more than 95%,and the model has a certain anti-interference ability.展开更多
The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg ...The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball. Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors im- pacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time. There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is ? h = 54.83452 ln(0.00723t +1.00486), where, ? h is the depth increment at the maximum load and t is the time.展开更多
Shrub presence has an important effect on the structuring of ground beetles in desert ecosystems. In this study, in order to determine how shrubs and different species influence ground beetle assemblages in a sandy de...Shrub presence has an important effect on the structuring of ground beetles in desert ecosystems. In this study, in order to determine how shrubs and different species influence ground beetle assemblages in a sandy desert scrubland dominated by two different shrub species, namely Calligonum mongolicum and Nitraria sphaerocarpa, we sampled the ground beetles using pitfall traps during spring, summer and autumn in 2012. At the community level, the activity density of the ground beetles was shown to be significantly higher under shrubs than in intershrub bare habitats in spring; but an opposite pattern occurred in autumn, suggesting the presence of sea- son-specific shrub effects on the activity density of the ground beetles. Meanwhile, at the trophic group level, the activity density and species richness of predators were significantly greater under shrubs than in intershrub bare habitats in spring, whereas an opposite trend occurred on the activity density in autumn. N. sphaerocarpa shrubs had a positive effect on the activity density of herbivores in the three seasons, and C. mongolicum shrubs had a positive effect on the activity density of detritivores in spring and autumn. At the species level, more Microdera sp. was captured under shrubs than in intershrub bare habitats in spring. During the same time, we also found that C. mongolicum shrubs had a positive effect on Blaps gobiensis in spring, Carabus sp. in autumn, and Tentyria sp. in spring and autumn, and N. sphaerocarpa shrubs had a positive effect on Cyphogenia chinensis, Sternoplax setosa in spring and summer, and Curculionidae sp. 1 in summer and autumn. The study results suggest that shrub presence, shrub species and season variation are important factors for ground beetle assemblages in this desert ecosystem, but the responses of beetles differed among trophic and taxonomic levels.展开更多
基金supported by the National Natural Science Foundation of China [grant numbers 42088101 and 42375048]。
文摘Due to the lack of accurate data and complex parameterization,the prediction of groundwater depth is a chal-lenge for numerical models.Machine learning can effectively solve this issue and has been proven useful in the prediction of groundwater depth in many areas.In this study,two new models are applied to the prediction of groundwater depth in the Ningxia area,China.The two models combine the improved dung beetle optimizer(DBO)algorithm with two deep learning models:The Multi-head Attention-Convolution Neural Network-Long Short Term Memory networks(MH-CNN-LSTM)and the Multi-head Attention-Convolution Neural Network-Gated Recurrent Unit(MH-CNN-GRU).The models with DBO show better prediction performance,with larger R(correlation coefficient),RPD(residual prediction deviation),and lower RMSE(root-mean-square error).Com-pared with the models with the original DBO,the R and RPD of models with the improved DBO increase by over 1.5%,and the RMSE decreases by over 1.8%,indicating better prediction results.In addition,compared with the multiple linear regression model,a traditional statistical model,deep learning models have better prediction performance.
基金supported by Forschungsanstalt für Waldo kologie und Forstwirtschaft(FAWF)of Landesforsten Rheinland-Pfalz(FF 5.3-01-2021)。
文摘Forest ecosystems are important for biodiversity conservation and human societies,but are under pressure due to climate change and human interventions.This applies to natural forests as well as tree plantations.The latter are globally widespread and therefore gaining increasing importance for biodiversity conservation.However,even after dieback due to increasing disturbance frequencies,such plantations are primarily managed for economic returns,leading to growing conflicts among stakeholders.In particular,the impact of forest management on biodiversity is being discussed.This study investigates the effects of five management approaches in a landscape severely affected by spruce(Picea abies L.)dieback on beetle diversity,conservation,and community composition.We considered direct effects of management and indirect effects of environmental parameters separately in ground-dwelling and flight-active beetles.Beetle diversity was strongly affected by forest management,with nonintervention deadwood stands being most beneficial for beetles.In addition,we show indirect effects of environmental factors.In general,parameters related to salvage logging(e.g.open canopies,tree stumps)influenced beetle diversity and conservation negatively,while positive effects were found for soil nutrient availability and plant species richness.Community composition differed strongly among management categories and indicated a lack of landscape connectivity for open habitat species,as we found only low proportions of such species even on salvage-logged sites.We propose a mixture of management approaches after bark beetle outbreaks,including a substantial proportion of non-intervention deadwood stands,to increase landscape heterogeneity and connectivity.This may increase overall biodiversity while addressing the concerns of both forestry and species conservation.
基金funded by the National Defense Science and Technology Innovation project,grant number ZZKY20223103the Basic Frontier InnovationProject at the Engineering University of PAP,grant number WJY202429+2 种基金the Basic Frontier lnnovation Project at the Engineering University of PAP,grant number WJY202408the Graduate Student Funding Priority Project,grant number JYWJ2024B006Key project of National Social Science Foundation,grant number 2023-SKJJ-A-116.
文摘This study introduces a novel algorithm known as the dung beetle optimization algorithm based on bounded reflection optimization andmulti-strategy fusion(BFDBO),which is designed to tackle the complexities associated with multi-UAV collaborative trajectory planning in intricate battlefield environments.Initially,a collaborative planning cost function for the multi-UAV system is formulated,thereby converting the trajectory planning challenge into an optimization problem.Building on the foundational dung beetle optimization(DBO)algorithm,BFDBO incorporates three significant innovations:a boundary reflection mechanism,an adaptive mixed exploration strategy,and a dynamic multi-scale mutation strategy.These enhancements are intended to optimize the equilibrium between local exploration and global exploitation,facilitating the discovery of globally optimal trajectories thatminimize the cost function.Numerical simulations utilizing the CEC2022 benchmark function indicate that all three enhancements of BFDBOpositively influence its performance,resulting in accelerated convergence and improved optimization accuracy relative to leading optimization algorithms.In two battlefield scenarios of varying complexities,BFDBO achieved a minimum of a 39% reduction in total trajectory planning costs when compared to DBO and three other highperformance variants,while also demonstrating superior average runtime.This evidence underscores the effectiveness and applicability of BFDBO in practical,real-world contexts.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(RS-2024-00449812,2022R1I1A3064173)the Korea government(MSIT)(No.RS-2024-00335915).
文摘Nature-inspired designs have increasingly influenced biomedical engineering by providing superior biomechanical performance and structural stability.In this study,the diabolical ironclad beetle elytra structure was applied to stent strut designs and thoroughly evaluated through various computational simulations to assess their potential to enhance the mechanical performance of WE43 magnesium alloy stents.Connected elliptical structures with a vertical-to-horizontal length ratio of 1:1.8 were incorporated in varying numbers and then compared to conventional laser-cut stents using 3-point bending,crush,crimping,and expansion tests,internal carotid artery insertion simulations,and computational fluid dynamics analyses.The results demonstrated that the biomimetic stents exhibited significantly improved stress distribution and reduced applied stress while maintaining hemodynamic stability.Computational fluid dynamics simulations further confirmed that the biomimetic could reduce wall shear stress and improve blood flow,thereby potentially minimizing the risk of restenosis and thrombosis.These findings suggest that diabolical ironclad beetle-inspired stent structures may offer enhanced biomechanical performance and clinical safety in magnesium-based endovascular interventions.
基金Project supported by the National Natural Science Foundation of China(No.62102130)the Central Government Guides Local Science and Technology Development Fund Project of China(No.226Z0201G)+4 种基金the Natural Science Foundation of Hebei Province of China(Nos.F2020204003 and F2024204001)the Hebei Youth Talents Support Project of China(No.BJ2019008)the Science and Technology Research Projects of Higher Education Institutions in Hebei Province of China(No.QN2024138)the Basic Scientific Research Funds Research Project of Hebei Provincial Colleges and Universities of China(No.KY2022073)the Hebei Province Higher Education Institution Scientific Research Project of China(No.QN2025192)。
文摘The dung beetle optimizer(DBO)is a metaheuristic algorithm with fast convergence and powerful search capabilities,which has shown excellent performance in solving various optimization problems.However,it suffers from the problems of easily falling into local optimal solutions and poor convergence accuracy when dealing with large-scale complex optimization problems.Therefore,we propose an adaptive DBO(ADBO)based on an elastic annealing mechanism to address these issues.First,the convergence factor is adjusted in a nonlinear decreasing manner to balance the requirements of global exploration and local exploitation,thus improving the convergence speed and search quality.Second,a greedy difference optimization strategy is introduced to increase population diversity,improve the global search capability,and avoid premature convergence.Finally,the elastic annealing mechanism is used to perturb the randomly selected individuals,helping the algorithm escape local optima and thereby improve solution quality and algorithm stability.The experimental results on the CEC 2017 and CEC 2022 benchmark function sets and MCNC benchmark circuits verify the effectiveness,superiority,and universality of ADBO.
文摘Any malfunctions of the actuators of the robots have the potential to destroy the robot’s normal motion,and most of the current actuator fault diagnosis methods are difficult to meet the requirements of simplifying the actuator modeling and solving the difficulty of fault data collection.To solve the problem of real-time diagnosis of actuator faults in the 3-PR(P)S parallel robot,the model of 3-PR(P)S parallel robot and data-driven-based method for the fault diagnosis are presented.Firstly,only the input-output relationship of the actuator is considered for modeling actuator faults,reducing the complexity of fault modeling and reducing the time consumption of parameter identification,thereby meeting the requirements of real-time diagnosis.A Simulink model of the electromechanical actuator(EMA)was constructed to analyze actuator faults.Then the short-term analysis method was employed for collecting the sample data of the slider position on the test platform of the EMA system and feature extraction.Training samples for neural networks are obtained.Furthermore,we optimized the Back Propagation(BP)neural network using the Dung Beetle Optimization Algorithm(DBO),which effectively resolved the weights and thresholds of the BP neural network.Compared to BP and Particle Swarm Optimization(PSO)-BP,the DBO-BP has better convergence,convergence rate,and the best-classifying quality.So,the classification for the different actuator faults is obviously improved.Finally,a fault diagnosis system was designed for the actuator of the 3-PR(P)S parallel robot,and the experimental results demonstrate that this system can detect actuator faults within 0.1 seconds.This work also provides the technical support for the fault-tolerant control of the 3-PR(P)S Parallel robot.
基金funded by the National Natural Science Foundation of China(U23A2063)the Gansu Province Top-notch Leading Talents Project(E339040101)the National Natural Science Foundation of China(41771290,42377043,41773086).
文摘Tenebrionid beetles represent a crucial arthropod taxon in the Gobi desert ecosystems owing to their species richness and high biomass,both of which are essential for maintaining ecosystem health and stability.However,the spatiotemporal variations of tenebrionid beetle assemblages in the Gobi desert remain poorly understood.In this study,the monthly dynamics of tenebrionid beetles in the central part of the Hexi Corridor,Northwest China,a representative area of the Gobi desert ecosystems,were monitored using pitfall trapping during 2015-2020.The following results were showed:(1)monthly activity of tenebrionid beetles was observed from March to October,with monthly activity peaking in spring and summer,and monthly activity periods and peak of tenebrionid beetle species exhibited interspecific differences that varied from year to year;(2)spatial distribution of tenebrionid beetle community was influenced by structural factors.Specifically,at a spatial scale of 24.00 m,tenebrionid beetle community was strongly and positively correlated with the dominant species,with distinct spatial distribution patterns observed for Blaps gobiensis and Microdera kraatzi alashanica;(3)abundance of tenebrionid beetles was positively correlated with monthly mean precipitation and monthly mean temperature,whereas monthly abundance of B.gobiensis and M.kraatzi alashanica was positively correlated with monthly mean precipitation;and(4)the cover of Reaumuria soongarica(Pall.)Maxim.and Nitraria sphaerocarpa Maxim.had a positive influence on the number of tenebrionid beetles captured.In conclusion,monthly variation in precipitation significantly influences the community dynamic of tenebrionid beetles,with precipitation and shrub cover jointly determining the spatial distribution pattern of these beetles in the Gobi desert ecosystems.
基金funded by the Internal Grant Agency of the Faculty of Forestry and Wood Science,No.43120/1312/3106the support of the Ministry of Agriculture of the Czech Republic,NAZV No.QK21020371.
文摘The natural composition of forests has undergone significant changes over recent centuries.A closer-to-natural tree species composition has long been perceived as key to a high biodiversity.We investigated the impact on communities of click beetles(Elateridae)caused by changes in the tree species composition of spruce monocultures compared to reference sites of recently unmanaged natural beech forests.To collect data,passive interception traps were distributed within managed spruce stands of different age classes and natural beech forests of various developmental stages.The beetle species richness was slightly but not significantly higher in the beech forests.The saproxylic species group was significantly more common in the spruce stands,whereas the group of nonsaproxylic species was significantly more abundant in the beech stands.In the commercial stands,the significantly highest species richness was in the clearings(0–10-year-old stands),and at this forest age class,the vast majority of the beetle species occurred in the spruce stands.In the developmental stages of the natural forest,a slightly higher beetle richness was found at the disintegration stage.The study results suggested that different tree species compositions and stand structures affect the communities of click beetles and substantially change their species composition and thus their response to external influences.Therefore,management of stands using diverse silvicultural systems is recommended for creating diverse ecological niches in forests.
基金supported by Forschungsanstalt fur Waldokologie und Forstwirtschaft (FAWF)of Landesforsten Rheinland-Pfalz (FF5.3-01-2021).
文摘Biodiversity loss is a significant problem at a global scale and may be amplified by climate change.In recent years,coniferous forests have had substantial die-back across Europe due to drought and subsequent bark-beetle outbreaks.As many studies on the consequences of disturbance and subsequent management have focused on natural stands,management implications for managed spruce stands are not well understood,even though such stands are widespread throughout Europe.In this study,beetle taxonomy,conservation value,and community com-position are compared among spruce plantations and four post-disturbance management approaches:standing dead-wood,lying deadwood,clear cuts,and long-term succession.Diversity and community composition differed significantly among management categories,while different beetle fami-lies responded similarly.Intact spruce stands harbored the lowest beetle diversity while the highest taxonomic diver-sity and conservation value was on clear cuts and stands with lying or standing deadwood.The proportion of forest specialists was highest in successional forests.In summary,different forest management categories harbored distinct beetle communities at the family-,species-,and ecological guild levels.Therefore,post-disturbance management should consider the landscape scale and include different management types.This enhances landscape heterogeneity and thus overall biodiversity but could also mitigate negative impacts of natural disturbances on ecosystem services.
基金funded by the National Key R&D Program of China(Grant No.2017YFC0703700).
文摘To improve the flexural properties of Beetle Elytron Plates(BEPs)and clarify the effect of the transition arcs(chamfers)between the skins and the trabeculae,the chamfers were set in BEPs,and then the influence of the chamfer on BEPs'mechanical properties was investigated via experimentation and the Finite Elemnent Method simulation(FEM).The results indicate that the influence of the chamfer on the flexural properties and ductility was most obvious in the Trabecular Beetle Elytron Plates(TBEPs),less obvious in the Honeycomb Plates(HPs)and basically no efiect was observed on End-trabecular Beetle Elytron Plates(EBEPs).The chamfer can improve the mechanical stability of EBEPSs.As the chamfer diameter increased in the BEPs,the length of the residual trabecular root on the skin increased when failure occurred in the TBEPs.The crack position in the honeycomb wallsof the HPs gradually shifted from the skin to the center.The EBEPs continued to exhibit oblique cracks.From the perspective of the force characteristics of these BEPs.combined with numerical simulation,the influence mechanism of the chamfer on their flcxural propertics was investigated.
基金supported by the National Basic Research Program of China (973 Program) (2011CB302102)by a Humboldt Fellowship (M.B.) from the Alexander von Humboldt Foundation
文摘This study investigates the dung beetle fauna in northern Pakistan, including Khyber Pakhtunkhwa province, Gilgit-Baltistan（formerly known as the Northern Areas of Pakistan）, and Federally Administered Tribal Areas, based on collections and determined specimens. The area is diverse and contains a variety of flora and fauna pertaining to different habitats. We conducted surveys in the Alpine Zone, Montane Temperate Forest and Tropical Deciduous Forest. Three genera and five species, Digitonthophagus gazelle,Digitonthophagus bonasus, Heliocopris midas, Heliocopris bucephalus and Gymnopleurus flagellates were collected. Identification keys and distribution notes are provided. Heliocopris bucephalus was found to be a new country record to Pakistan.
文摘A scanning electron microscope was used to observe the structures of the setae on the surface of a dung beetle Copris ochus, Motschulsky. There are lots of setae on the body surface, especially on the ventral part surface and lateral to the legs which are different in size, arrangement and shape. These setae have different lengths and many thorns on the whole seta. The top ends of these setae stand up without furcations which direct uprightly towards the surface of the touched soil. By the method of removing these setae, getting the insect weight before and after digging into the dung we affirm farther that the setae on the beetle body surface form the anti-stick and non-adherent gentle interface. The soil machines and components made by imitating the gentle body surface of beetles have favorable non-adherent results.
基金National Natural Science Foundation of China(5197206321501127+3 种基金51502185)Natural Science Foundation of Fujian Province(2019J01256)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX191916)the funds from China postdoctoral science foundation grant(2019TQ0061)。
文摘Efficient collection of water from fog provides a potential solution to solve the global freshwater shortage problem, particularly in the desert or arid regions. In this work, a flexible and highly efficient fog collector was prepared by mimicking the back exoskeleton structure of the Namib desert beetle. The improved fog collector was constructed by a superhydrophobic-superhydrophilic patterned fabric via a simple weaving method, followed by in-situ deposition of copper particles. Compared with the conventional fog collector with a plane structure, the fabric has shown a higher water-harvesting rate at 1432.7 mg/h/cm2,owing to the biomimetic three-dimensional structure, its enhanced condensation performance enabled by the copper coating and the rational distribution of wetting units. The device construction makes use of the widely available textile materials through mature manufacturing technology, which makes it highly suitable for large-scale industrial production.
基金supported by the National Key Research and Development Program of China(Grant Number:2017YFD0600104)the Shenyang Science and Technology Planning Project(Grant Number:18-400-3-03)。
文摘In order to found new carriers of pine wood nematode(PWN),Bursaphelenchus xylophilus,beetles were collected from pine wilt disease-affected areas in six provinces in China.A total of 8830 beetles of 29 species was collected and examined to determine whether they were PWN carriers.Eight species were identified as carriers.Results included the first worldwide report of Monochamus uigromaculatus,Semanotus siuoauster,and Uraecha angusta being carriers of PWN,and the first report from China of A rhopalus rusticus carrying PWN.Monochamus alternatus was commonly collected in all six provinces and was the dominant species in four inland affected areas and A.rusticus was dominant in two coastal affected areas.The species varied between different neighboring regions in the same province.The distribution of the same species varied considerably over different regions.
文摘AIM To determine short-and long-term outcomes of endoscopic submucosal dissection(ESD) using the stag beetle(SB) knife, a scissor-shaped device.METHODS Seventy consecutive patients with 96 early esophageal neoplasms, who underwent ESD using a SB knife at Kure Medical Center and Chugoku Cancer Center, Japan, between April 2010 and August 2016, were retrospectively evaluated. Clinicopathological characteristics of lesions and procedural adverse events were assessed. Therapeutic success was evaluated on the basis of en bloc, histologically complete, and curative or non-curative resection rates. Overall and tumor-specific survival, local or distant recurrence, and 3-and 5-year cumulative overall metachronous cancer rates were also assessed.RESULTS Eligible patients had dysplasia/intraepithelial neoplasia(22%) or early cancers(squamous cell carcinoma, 78%). The median procedural time was 60 min and on average, the lesions measured 24 mm in diameter, yielding 33-mm tissue defects. The en bloc resection rate was 100%, with 95% and 81% of dissections deemed histologically complete and curative, respectively. All procedures were completed without accidental incisions/perforations or delayed bleeding. During follow-up(mean, 35 ± 23 mo), no local recurrences or metastases were observed. The 3-and 5-year survival rates were 83% and 70%, respectively, with corresponding rates of 85% and 75% for curative resections and 74% and 49% for noncurative resections. The 3-and 5-year cumulative rates of metachronous cancer in the patients with curative resections were 14% and 26%, respectively.CONCLUSION ESD procedures using the SB knife are feasible, safe, and effective for treating early esophageal neoplasms, yielding favorable short-and long-term outcomes.
基金Supported by Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province of China(Grant No.CX(19)3081)Key Research and Development Program of Jiangsu Province of China(Grant No.BE2018127).
文摘In the process of Wavelet Analysis,only the low-frequency signals are re-decomposed,and the high-frequency signals are no longer decomposed,resulting in a decrease in frequency resolution with increasing frequency.Therefore,in this paper,firstly,Wavelet Packet Decomposition is used for feature extraction of vibration signals,which makes up for the shortcomings of Wavelet Analysis in extracting fault features of nonlinear vibration signals,and different energy values in different frequency bands are obtained by Wavelet Packet Decomposition.The features are visualized by the K-Means clustering method,and the results show that the extracted energy features can accurately distinguish the different states of the bearing.Then a fault diagnosis model based on BP Neural Network optimized by Beetle Algo-rithm is proposed to identify the bearing faults.Compared with the Particle Swarm Algorithm,Beetle Algorithm can quickly find the error extreme value,which greatly reduces the training time of the model.At last,two experiments are conducted,which show that the accuracy of the model can reach more than 95%,and the model has a certain anti-interference ability.
文摘The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball. Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors im- pacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time. There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is ? h = 54.83452 ln(0.00723t +1.00486), where, ? h is the depth increment at the maximum load and t is the time.
基金funded by the National Basic Research Program of China (2013CB429903)the National Natural Science Foundation of China (41201248, 31170496)
文摘Shrub presence has an important effect on the structuring of ground beetles in desert ecosystems. In this study, in order to determine how shrubs and different species influence ground beetle assemblages in a sandy desert scrubland dominated by two different shrub species, namely Calligonum mongolicum and Nitraria sphaerocarpa, we sampled the ground beetles using pitfall traps during spring, summer and autumn in 2012. At the community level, the activity density of the ground beetles was shown to be significantly higher under shrubs than in intershrub bare habitats in spring; but an opposite pattern occurred in autumn, suggesting the presence of sea- son-specific shrub effects on the activity density of the ground beetles. Meanwhile, at the trophic group level, the activity density and species richness of predators were significantly greater under shrubs than in intershrub bare habitats in spring, whereas an opposite trend occurred on the activity density in autumn. N. sphaerocarpa shrubs had a positive effect on the activity density of herbivores in the three seasons, and C. mongolicum shrubs had a positive effect on the activity density of detritivores in spring and autumn. At the species level, more Microdera sp. was captured under shrubs than in intershrub bare habitats in spring. During the same time, we also found that C. mongolicum shrubs had a positive effect on Blaps gobiensis in spring, Carabus sp. in autumn, and Tentyria sp. in spring and autumn, and N. sphaerocarpa shrubs had a positive effect on Cyphogenia chinensis, Sternoplax setosa in spring and summer, and Curculionidae sp. 1 in summer and autumn. The study results suggest that shrub presence, shrub species and season variation are important factors for ground beetle assemblages in this desert ecosystem, but the responses of beetles differed among trophic and taxonomic levels.
