Mental health is a significant issue worldwide,and the utilization of technology to assist mental health has seen a growing trend.This aims to alleviate the workload on healthcare professionals and aid individuals.Num...Mental health is a significant issue worldwide,and the utilization of technology to assist mental health has seen a growing trend.This aims to alleviate the workload on healthcare professionals and aid individuals.Numerous applications have been developed to support the challenges in intelligent healthcare systems.However,because mental health data is sensitive,privacy concerns have emerged.Federated learning has gotten some attention.This research reviews the studies on federated learning and mental health related to solving the issue of intelligent healthcare systems.It explores various dimensions of federated learning in mental health,such as datasets(their types and sources),applications categorized based on mental health symptoms,federated mental health frameworks,federated machine learning,federated deep learning,and the benefits of federated learning in mental health applications.This research conducts surveys to evaluate the current state of mental health applications,mainly focusing on the role of Federated Learning(FL)and related privacy and data security concerns.The survey provides valuable insights into how these applications are emerging and evolving,specifically emphasizing FL’s impact.展开更多
The effect of Cr addition on nickel aluminium bronze(NAB)alloy microstructure,mechanical properties,and erosion-corrosion behaviour has been studied.The results show that Cr addition does not change the composition of...The effect of Cr addition on nickel aluminium bronze(NAB)alloy microstructure,mechanical properties,and erosion-corrosion behaviour has been studied.The results show that Cr addition does not change the composition of the precipitated phases,more Cr entered theκphase and a small amount of Cr solubilized in the matrix,which increase the hardness of theκand matrix and decrease the potential difference between theκand matrix.NAB alloy with Cr shows high erosion-corrosion resistance at high flow rate conditions,due to its lower phase potential difference and higher surface hardness.At the flow rate of 3 m·s^(-1),the corrosion rate is 0.076 mm·year^(-1),which is~20%lower than that of the unadded Cr sample.Moreover,the corrosion product film contains Cr_(2)O_(3)and Cr^(3+),which improves the densification of the film and raises alloy’s corrosion resistance with Cr addition.The combination of mechanical and corrosion resistant properties may qualify this alloy as a potential candidate material for sustainable and safe equipment.展开更多
The functionally graded materials(FGMs)are obtained by various processes.Although a few FGMs are obtained naturally,such as oyster,pearl,and bamboo,additive manufacturing(AM),known as 3D printing,is a net-shaped manuf...The functionally graded materials(FGMs)are obtained by various processes.Although a few FGMs are obtained naturally,such as oyster,pearl,and bamboo,additive manufacturing(AM),known as 3D printing,is a net-shaped manufacturing process employed to manufacture complex 3D objects without tools,molds,assembly,and joining.Currently,commercial AM techniques mostly use homogeneous composition with simplified geometric descriptions,employing a single material across the entire component to achieve functional graded additive manufacturing(FGAM),in contrast to multi-material FGAM with heterogeneous structures.FGMs are widely used in various fields due to their mechanical property advantages.Because FGM plays a significant role in the industrial production,the characteristics and mechanical behaviour of FGMs prepared by AM were reviewed.In this review,the research on FGMs and AM over the past 30 years was reviewed,suggesting that future researchers should focus on the application of artificial intelligence and machine learning technologies in industry to optimize the process parameters of different gradient systems.展开更多
This study aimed to explore the application effect of the medical and nursing integration working mode in children with inguinal hernia undergoing laparoscopic surgery and to provide a basis for its clinical promotion...This study aimed to explore the application effect of the medical and nursing integration working mode in children with inguinal hernia undergoing laparoscopic surgery and to provide a basis for its clinical promotion.A total of 70 children with inguinal hernia admitted to our hospital from July 2023 to June 2024 and treated with laparoscopic surgery were selected as study subjects and randomly divided into an observation group and a control group,with 35 cases in each.Both groups received routine nursing care,while the observation group additionally adopted the integrated medical and nursing working mode,including systematic health education,psychological interventions,and postoperative follow-up from admission to discharge.The anxiety and depression scores of the two groups before and after surgery,medical compliance index,and incidence of complications during hospitalization were compared.Results showed that the preoperative anxiety scores of the observation and control groups were(14.01±1.07)and(14.62±2.31),respectively,with no statistically significant difference(P>0.05);however,postoperative anxiety scores were significantly lower in the observation group(4.01±0.77)compared to the control group(6.62±0.31)(P<0.05).Similarly,preoperative depression scores were(15.11±1.22)in the observation group and(15.41±2.01)in the control group(P>0.05),but postoperative depression scores were significantly reduced in the observation group(4.24±0.61)compared to the control group(7.12±0.54)(P<0.05).After intervention,the medical compliance behavior index in the observation group was(83.31±5.92),significantly higher than(75.34±6.73)in the control group(P<0.05).Regarding postoperative complications,only 1 case(2.86%)occurred in the observation group,while 8 cases(22.86%)were reported in the control group,showing a statistically significant difference(P<0.05).In conclusion,the medical and nursing integration working mode effectively improves the perioperative psychological state of children,enhances medical compliance,reduces postoperative complications,and is worthy of widespread clinical application.展开更多
A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence ...A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.展开更多
In this paper,the fracture behaviors and interface stresses of sintered Nd-Fe-B magnets were investigated.It was revealed that cracks propagated along the interfaces of Nd_(2)Fe_(14)B/Nd_(2)Fe_(14)B,Nd_(2)Fe_(14)B/Nd-...In this paper,the fracture behaviors and interface stresses of sintered Nd-Fe-B magnets were investigated.It was revealed that cracks propagated along the interfaces of Nd_(2)Fe_(14)B/Nd_(2)Fe_(14)B,Nd_(2)Fe_(14)B/Nd-rich phases and within Nd-rich phases.The misfits between 2:14:1 and Nd-rich phases were quantitatively determined,reflecting the concentration of interface stresses in magnet.Grain boundaries of magnet were reconstructed by diffusing Tb-containing and Tb-free sources,respectively.The Tb-rich shells at extensive layers of 2:14:1 grains caused lattice distortion,i.e.,internal stresses,resulting in the crack mode changing from intergranular to transgranular in near surfaces of Tb-containing diffused magnets.Therefore,the bending strengths were deteriorated although the coercivities were apparently enhanced.In the case of Tb-free Pr-Cu diffused magnet,the Pr and Cu elements were enriched at grain boundaries,and the misfits between 2:14:1 and Nd-rich phases were declined,lowering interface stresses and strengthening grain boundaries.The mechanical and magnetic properties of Pr-Cu diffused magnet were simultaneously improved.展开更多
The effectiveness of using vegetation to stabilise shallow soil slopes heavily depends on the survival of vegetation,yet the amplification of extreme events induced by climate change threatens the health of plants cov...The effectiveness of using vegetation to stabilise shallow soil slopes heavily depends on the survival of vegetation,yet the amplification of extreme events induced by climate change threatens the health of plants covering slopes.Hydrochar is an environmentally friendly soil amender that can achieve the potential benefits of promoting plant growth for slope stabilisation and facilitation of waste upcycling.The mechanism underlying the hydrochar effects on the mechanical behaviour of unsaturated soils remains unclear.This study investigated the influence of grass-derived hydrochar on the water retention,compressibility,and shear strength of a compacted siltyeclay sand.Soil microstructural changes due to hydrochar amendment were measured to explain the soilehydrochar hydromechanical interaction.The increase in suction resulted in a less significant increase in yield stress and a negligible reduction in compressibility of the hydrochar-amended soil compared with the unamended case.This phenomenon was observed because hydrochar addition reduced the large pores with diameters greater than the macropore peak of 60 mm due to pore filling by hydrochar particles,resulting in a less substantial volume contraction during drying.Hydrochar introduced more significant effects on the soil’s shear strength in an unsaturated state compared to a saturated case.Despite the similarity of the unsaturated amended soil with the critical-state friction angle to the saturated case,the former exhibited a greater shear strength because the hydrochar addition improved water retention capability.As a result,the degree of saturation and,hence,Bishop’s effective stress were higher than those for the unamended case for a given suction.展开更多
The radula is a crucial adaptation for food-processing in molluscs.A deeper understanding of the interaction between the radula and the preferred food is lacking,complicating the inference of the precise ecological ro...The radula is a crucial adaptation for food-processing in molluscs.A deeper understanding of the interaction between the radula and the preferred food is lacking,complicating the inference of the precise ecological roles of radular structures.This study presents the first experimental set-up that allows to study the influence of the radular morphology,specifically the degree of tooth-tooth interlocking(so-called collective effect),on the feeding efficiency.For this purpose,physical 3D models of the teeth were designed using CAD software and 3D printing technique.The feeding efficiencies with models of different degree of interlocking were determined by tensile tests,pulling the models trough agar gels with different viscosities.The forces generated by the models and the masses of the removed gel fragments were determined.We found,that radular models with a high degree of tooth–tooth interlocking performed best as they were able to remove most agar.We additionally broke the teeth and determined,that the teeth with the highest degree of interlocking could resist to highest force.Overall,the study highlights the complex interplay between radular morphology and its ecological function,suggesting that even minor morphological alterations can significantly impact the efficiency and effectiveness of food gathering.Understanding these interactions cannot only shed light on the ecological adaptations of molluscs,but provide further insights into development of more effective grinding,scraping,and cleaning technical devices.展开更多
Glue-laminated timber(GLT)is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties.However,the fire performance of GLT varies significantly due to t...Glue-laminated timber(GLT)is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties.However,the fire performance of GLT varies significantly due to the natural and uncertain phenomena(moisture,exposure time,isotropic,homogenous properties,etc.)of fire and timber.This makes it difficult to predict the fire behaviour of the GLT structural elements.To ensure building safety,it is crucial to assess GLT’s fire behaviour and post-fire structural integrity during the design stages.This study conducted the experimental tests of GLT beams(280 mm×560 mm)without loading(1.4 m)and under a four-point bending load(5.4 m).Tests identified thermal behaviour and charring rates of GLT beam.Then,the residual stiffness of the GLT beam was calculated,and the charring rates of the beams were compared with Australian and European standards.Reliability analysis was conducted for beams for a fire exposure of 120 min,considering the charring rates observed through the analysis and simulating the fire insulations.Results show that the charring rate of GLT made with spruce pine timber varied between 0.43 and 0.81 mm/min,with a mean rate of 0.7 mm/min,aligning with both Australian and European standards.However,considering timber density and moisture content,the charring rates in Australian standards were conservative.The study also found that structural capacity significantly degrades under fire,with a 22%reduction in flexural stiffness after 120 min of exposure.Additionally,GLT beams can safely function for 30 min under 75%of their design moment capacity and for 60 min under 50%capacity.展开更多
Two widespread bird species in Sri Lanka’s dry zone,Pycnonotus cafer(Red-vented Bulbul,RVBB)and Pycnonotus luteolus(White-browed Bulbul,WBBB),were studied to understand their foraging dynamics and ecology.The researc...Two widespread bird species in Sri Lanka’s dry zone,Pycnonotus cafer(Red-vented Bulbul,RVBB)and Pycnonotus luteolus(White-browed Bulbul,WBBB),were studied to understand their foraging dynamics and ecology.The research was conducted from October 2022 to February 2023 in Mihintale Sanctuary(80.30′11.24″E,8.21′04.63″N)and the Faculty of Applied Sciences,Rajarata University of Sri Lanka(80.502206″E,8.353090″N).Data were obtained through focal sampling,opportunistic observations,and mist netting.Both species predominantly foraged on twigs,using gleaning as the dominant food-handling technique.RVBB foraged mostly at the canopy level,while WBBB foraged primarily at the sub-canopy level.Fruits constituted the major food type for both species.RVBB and WBBB utilized 10 and 7 plant species,respectively,with Grewia helicterifolia being the primary foraging plant.Minimal foraging was observed on Croton sp.(RVBB)and Hugonia mistax(WBBB).The correlation between nutritional components and the consumption of both species revealed a preference for foods with lower protein,higher fat,and ash content.There was no linear correlation between gape width and fruit size(r=-0.21,P=0.69)for both species.The standardized dietary niche breadth indicated both species are specialists,with a high pairwise dietary niche overlap(0.9854).These findings highlight the niche-specific foraging adaptations of RVBB and WBBB within Mihintale,emphasizing their distinct strategies in utilizing plant species,fruit sizes,and foraging heights.Understanding such ecological dynamics is essential for habitat conservation efforts and ensuring the availability of key foraging resources for these species in the dry zone.展开更多
Exploring alternative aggregates or recycled aggregates to substitute traditional concrete aggregates,particularly sand aggregates,which are becoming more limited and must comply with environmental protection standard...Exploring alternative aggregates or recycled aggregates to substitute traditional concrete aggregates,particularly sand aggregates,which are becoming more limited and must comply with environmental protection standards,is essential.Research has explored various alternative materials to sand in concrete,including concrete from demolished buildings,and broken glass from projects,among others.Investigating the use of recycled broken glass to substitute sand aggregates and implementing this research in compression columns is crucial.This paper examines the compressive behavior of reinforced concrete columns that utilize recycled glass particles as a substitute for sand in concrete.The research findings establish the relationships:load and vertical displacement,load and deformation at the column head,mid-column,and column base;the formation and propagation of cracks in the column,while considering factors such as the percentage of recycled glass,the arrangement of stirrups,and the amount of load-bearing steel influencing the performance of square reinforced concrete columns under compression.The feasibility of using recycled glass as a substitute for sand in column structures subjected to compression has been demonstrated,with the ideal replacement content for sand aggregate in reinforced concrete columns in this study ranging from 0%to 10%.The column’s load-bearing ability dropped from 250 kN to 150 kN when 100%recycled glass was used instead of sand.This is a 40%drop,and cracks started to show up sooner.The research will support recycling broken glass instead of using sand in building,improving the environment and reducing natural sand use.展开更多
Expansive soils, prone to being influenced by the environmental conditions, undergo expansion when water is introduced and shrinkage upon drying. This persistent volumetric fluctuation can induce differential movement...Expansive soils, prone to being influenced by the environmental conditions, undergo expansion when water is introduced and shrinkage upon drying. This persistent volumetric fluctuation can induce differential movements and result in cracking of structures erected upon them. The present research focuses on characterizing the behavior of pavements erected on expansive clays subjected to swelling and shrinkage cycles. Direct shear tests and oedometer tests were conducted in the laboratory on samples of expansive soils undergoing swelling-shrinkage cycles. The experimental data reveal a significant decrease in shear strength, evidenced by a reduction in shear parameters (internal friction angle, cohesion) and a decrease in the modulus of elasticity as the number of cycles increases. A numerical model based on the finite element method was developed to simulate the behavior of a pavement on an expansive clay substrate. The model results indicate an increase in total displacements with the increase in the number of shrinkage-swelling cycles, demonstrating a progressive degradation of the soil’s mechanical behavior. This study contributes to a better understanding of the complex phenomena governing the behavior of expansive soils and serves as a foundation for developing effective management and mitigation strategies for road infrastructures.展开更多
This study examined the relationship between leader-employee calling congruence on employees’voice behaviour.Participants were 173 leader-employee dyads from the Chinese service industry.They completed online surveys...This study examined the relationship between leader-employee calling congruence on employees’voice behaviour.Participants were 173 leader-employee dyads from the Chinese service industry.They completed online surveys on calling,perceived insider status,and voice behaviour.Results from polynomial regression and response surface analysis showed that employees perceived insider status to be weaker with the low leader-low subordinate calling congruence,and stronger with high leader and high subordinate calling congruence.Employees perceived insider status is stronger in low leader and high subordinate calling incongruence compared with high leader and low subordinate calling incongruence.Perceived insider status plays a mediating role among calling congruence and voice behaviour.This study’sfindings suggest pathways of calling congruence on voice behaviour,which are important for promoting employee voice behaviour and guiding organisational recruitment in the workplace.展开更多
Controlling the adhesion of potentially corrosive substances from flue gas on grate bar is crucial for extending the operational lifespan of the equipment.The adhesive behaviour and mechanism of ultrafine particulate ...Controlling the adhesion of potentially corrosive substances from flue gas on grate bar is crucial for extending the operational lifespan of the equipment.The adhesive behaviour and mechanism of ultrafine particulate matters(UPM)throughout the sintering process were elucidated,and measures to control adhesion on grate bars were developed.Research findings indicated that a small quantity of UPM were found on grate bar during the initial sintering stages(ignition stage and middle stageⅠandⅡ).The main compositions of UPM were FexOy-rich,CaO-rich,and aluminium silicate-rich particles.In contrast,corrosive substances like alkali metal compounds were almost absent.These UPM adhered onto grate bar primarily through inertial impaction.When moving to the final sintering stages(middle stageⅢand temperature rising stage),many UPM rich in corrosive substances like NaCl and KCl adhered to the grate bar.These UPM adhered to grate bar through thermal diffusion and vortex deposition.Solid waste water washing technology can greatly decrease the quantity of UPM(rich in NaCl and KCl)on the grate bar due to vortex deposition and thermal diffusion,and it represents a potentially promising way to control adhesion and corrosion on grate bars.展开更多
This essay evaluates the behavioural dynamics generated by profit incentives and compares them with those in government-owned and charitable enterprises.Drawing on neoclassical microeconomics,agency theory,and institu...This essay evaluates the behavioural dynamics generated by profit incentives and compares them with those in government-owned and charitable enterprises.Drawing on neoclassical microeconomics,agency theory,and institutional economics,it shows how the profit motive drives cost minimization,allocative efficiency,innovation,and consumer responsiveness.Profit expectations,formalized in endogenous growth models,act as catalysts for technological progress and dynamic efficiency,while agency-theoretic governance mechanisms align managerial incentives with shareholder interests.In contrast,government-owned enterprises operate under multi-objective welfare functions,often constrained by soft budget expectations,political interference,and X-inefficiencies that dilute efficiency.Charitable organizations,structured by the non-distribution constraint,emphasize social trust,equity,and mission fulfilment,supported by warm-glow altruism but constrained by free-rider problems and underfunding.A comparative evaluation suggests that profit-driven firms outperform in competitive markets producing private goods,whereas government and charitable forms play essential roles in addressing market failures and providing public or credence goods.The analysis affirms the institutionalist principle that ownership and governance structures must be aligned with the nature of the goods or services delivered.展开更多
Background: Waste management in Western Area Rural (WAR), Sierra Leone, is plagued by infrastructural and socioeconomic challenges, leading to environmental and health hazards such as flooding, air pollution, and vect...Background: Waste management in Western Area Rural (WAR), Sierra Leone, is plagued by infrastructural and socioeconomic challenges, leading to environmental and health hazards such as flooding, air pollution, and vector-borne diseases. Despite awareness campaigns, informal methods like open dumping and burning dominate. This study applies the Theory of Planned Behaviour (TPB) to analyse how attitudes, subjective norms, and perceived behavioural control influence waste management practices and barriers to proper disposal with potential solutions. Methods: A quantitative approach was employed, using stratified random sampling and structured questionnaires to collect data from 333 participants across ten communities in Western Area Rural (WAR). Data were analyzed using descriptive and inferential statistics to examine the relationship between socio-demographic variables and waste management practices. Results: While 98.2% of respondents acknowledged the importance of waste management, limited perceived behavioural control driven by financial constraints (83.8%), inadequate education (83.2%), and insufficient infrastructure (66.4%) hindered effective waste disposal ultimately linking health and environmental risks, such as flooding and marine pollution from plastic waste. Most respondents (68.8%) lacked access to formal waste services, with disposal occurring primarily via open dumping (62.9%) and burning (17.9%). Subjective norms reinforced informal disposal, as community waste-burning remained an accepted practice. Women were disproportionately affected due to economic constraints and larger household sizes. Despite these challenges, 93.1% were willing to engage in community clean-up efforts, indicating strong pro-environmental attitudes constrained by structural barriers. Conclusion: Findings underscore the need for integrated waste management strategies informed by TPB, targeting attitudes through education, reshaping social norms through community-driven initiatives, and enhancing perceived behavioural control by improving infrastructure and financial accessibility. Addressing gender disparities, strengthening public-private partnerships, and expanding recycling and composting programs can foster sustainable waste management in resource-constrained settings.展开更多
1 Move over Simone Biles,because grey whales might just be the next Olympic champions.This conclusion can be drawn from a new study that filmed these amazing animals doing underwater headstands(头倒立)and other moves....1 Move over Simone Biles,because grey whales might just be the next Olympic champions.This conclusion can be drawn from a new study that filmed these amazing animals doing underwater headstands(头倒立)and other moves.2 As part of a seven-year project,scientists used drones(无人驾驶飞机)to observe a group of 200 grey whales off the coasts of Oregon,Washington,northern California and southern Canada.The new study findings,published in Animal Behaviour,revealed that grey whales do headstands by pressing their mouths against the ocean floor while searching for something to eat.Scientists also noticed that when doing headstands,grey whales move like human synchronized swimmers.展开更多
Polyurethane foam,when used as a compressible layer in deep soft rock tunnels,offers a feasible solution to reduce the support pressure on the secondary lining.The foam spraying method using sprayed polyurethane mater...Polyurethane foam,when used as a compressible layer in deep soft rock tunnels,offers a feasible solution to reduce the support pressure on the secondary lining.The foam spraying method using sprayed polyurethane material is convenient for engineering applications;however,the compressive behaviour and feasibility of sprayed polyurethane material as a compressible layer remain unclear.To address this gap,this study conducts uniaxial compression tests and scanning electron microscope(SEM)tests to investigate the compressive behaviour of the rigid foams fabricated from a self-developed polyurethane spray material.A peridynamics model for the composite lining with a polyurethane compressible layer is then established.After validating the proposed method by comparison with two tests,a parametric study is carried out to investigate the damage evolution of the composite lining with a polyurethane compressible layer under various combinations of large deformations and compressible layer parameters.The results indicate that the polyurethane compressible layer effectively reduces the radial deformation and damage index of the secondary lining while increasing the damage susceptibility of the primary lining.The thickness of the polyurethane compressible layer significantly influences the prevention effect of large deformation-induced damage to the secondary lining within the density range of 50e100 kg/m^(3).In accordance with the experimental and simulation results,a simple,yet reasonable and convenient approach for determining the key parameters of the polyurethane compressible layer is proposed,along with a classification scheme for the parameters of the polyurethane compressible layer.展开更多
Rolling noise is an important source of railway noise and depends also on the dynamic behaviour of a railway track.This is characterized by the point or transfer mobility and the track decay rate,which depend on a num...Rolling noise is an important source of railway noise and depends also on the dynamic behaviour of a railway track.This is characterized by the point or transfer mobility and the track decay rate,which depend on a number of track parameters.One possible reason for deviations between simulated and measured results for the dynamic track behaviour is the uncertainty of the value of some track parameters used as input for the simulation.This in turn results in an uncertainty in the simulation results.In this contribution,it is proposed to use the general transformation method to assess a uncertainty band for the results.Most relevant input parameters for determining the point input mobility and the track decay rate for a ballasted track are analysed with regard to the uncertainties and for the value of each an interval is determined.Then,the general transformation method is applied to four different simulation methods,working both in the frequency and time domains.For one example track,the resulting uncertainty bands are compared to one dataset with measurements for the point mobility and the track decay rate.In addition,a sensitivity analysis is performed to determine the parameters that significantly influence the overall result.While all four simulation methods produce broad uncertainty bands for the results,none did match the measured results for the point mobility and the track decay rate over the entire frequency range considered.Besides the large influence of the uncertain pad stiffness,it turned out that the rail wear is also a significant source of uncertainty of the results.Overall,it is demonstrated that the proposed approach allows assessing the influence of uncertain input parameters in detail.展开更多
The exploratory synthesis and structural characterization of twodimensional(2D)honeycomb structured Ru-based compounds are key focuses in inorganic materials research,due to the various exotic electronic states arisin...The exploratory synthesis and structural characterization of twodimensional(2D)honeycomb structured Ru-based compounds are key focuses in inorganic materials research,due to the various exotic electronic states arising from the interplay of electron correlations and spinorbit coupling.Among these compounds,α-RuCl_(3) and RuBr_(3) are considered as the most promising candidates for quantum spin liquid(QSL)materials[1–3].As a homolog,α-RuI3 has attracted significant interest,but it still remains relatively unexplored.Recently,it was synthesized by high-temperature and high-pressure solid-state reaction,but reported to be different crystal structures by independent groups.Ni et al.and Nawa et al.considerα-RuI3 to be R-3(3R)and P-31c(2H)space group,respectively[4,5].Both structures have typical 2D characteristics,in which the edge-sharing RuI6 octahedra form honeycomb layers stacked along the c-axis.The primary difference lies in that the honeycomb layers stack in ABCABC mode in the 3R phase,while in ABAB mode in the 2H phase(Fig.S1).Yang et al.discussed the stability of 3R and 2H polymorphs in terms of the total energies and dynamics,finding both structures are stable.However,the total energy of the 2H phase is slightly higher,2.58 meV than that of the 3R analog[6].When it comes to the conductivity behaviour,α-RuCl3 andα-RuBr_(3) are semiconductors as normally observed in QSL materials.In contrast,α-RuI_(3) exhibits metallic response.In 2D materials,the band structure may be drastically modified by altering the stacking order[7].Hence,determining the crystal structure ofα-RuI_(3) is urgently required,which is a key step in comprehensive and in-depth analysis of its physical properties.展开更多
文摘Mental health is a significant issue worldwide,and the utilization of technology to assist mental health has seen a growing trend.This aims to alleviate the workload on healthcare professionals and aid individuals.Numerous applications have been developed to support the challenges in intelligent healthcare systems.However,because mental health data is sensitive,privacy concerns have emerged.Federated learning has gotten some attention.This research reviews the studies on federated learning and mental health related to solving the issue of intelligent healthcare systems.It explores various dimensions of federated learning in mental health,such as datasets(their types and sources),applications categorized based on mental health symptoms,federated mental health frameworks,federated machine learning,federated deep learning,and the benefits of federated learning in mental health applications.This research conducts surveys to evaluate the current state of mental health applications,mainly focusing on the role of Federated Learning(FL)and related privacy and data security concerns.The survey provides valuable insights into how these applications are emerging and evolving,specifically emphasizing FL’s impact.
基金supported by Beijing Nova Program(No.20230484371)the National Key Research and Development Program of China(No.2021YFB3700700).
文摘The effect of Cr addition on nickel aluminium bronze(NAB)alloy microstructure,mechanical properties,and erosion-corrosion behaviour has been studied.The results show that Cr addition does not change the composition of the precipitated phases,more Cr entered theκphase and a small amount of Cr solubilized in the matrix,which increase the hardness of theκand matrix and decrease the potential difference between theκand matrix.NAB alloy with Cr shows high erosion-corrosion resistance at high flow rate conditions,due to its lower phase potential difference and higher surface hardness.At the flow rate of 3 m·s^(-1),the corrosion rate is 0.076 mm·year^(-1),which is~20%lower than that of the unadded Cr sample.Moreover,the corrosion product film contains Cr_(2)O_(3)and Cr^(3+),which improves the densification of the film and raises alloy’s corrosion resistance with Cr addition.The combination of mechanical and corrosion resistant properties may qualify this alloy as a potential candidate material for sustainable and safe equipment.
文摘The functionally graded materials(FGMs)are obtained by various processes.Although a few FGMs are obtained naturally,such as oyster,pearl,and bamboo,additive manufacturing(AM),known as 3D printing,is a net-shaped manufacturing process employed to manufacture complex 3D objects without tools,molds,assembly,and joining.Currently,commercial AM techniques mostly use homogeneous composition with simplified geometric descriptions,employing a single material across the entire component to achieve functional graded additive manufacturing(FGAM),in contrast to multi-material FGAM with heterogeneous structures.FGMs are widely used in various fields due to their mechanical property advantages.Because FGM plays a significant role in the industrial production,the characteristics and mechanical behaviour of FGMs prepared by AM were reviewed.In this review,the research on FGMs and AM over the past 30 years was reviewed,suggesting that future researchers should focus on the application of artificial intelligence and machine learning technologies in industry to optimize the process parameters of different gradient systems.
文摘This study aimed to explore the application effect of the medical and nursing integration working mode in children with inguinal hernia undergoing laparoscopic surgery and to provide a basis for its clinical promotion.A total of 70 children with inguinal hernia admitted to our hospital from July 2023 to June 2024 and treated with laparoscopic surgery were selected as study subjects and randomly divided into an observation group and a control group,with 35 cases in each.Both groups received routine nursing care,while the observation group additionally adopted the integrated medical and nursing working mode,including systematic health education,psychological interventions,and postoperative follow-up from admission to discharge.The anxiety and depression scores of the two groups before and after surgery,medical compliance index,and incidence of complications during hospitalization were compared.Results showed that the preoperative anxiety scores of the observation and control groups were(14.01±1.07)and(14.62±2.31),respectively,with no statistically significant difference(P>0.05);however,postoperative anxiety scores were significantly lower in the observation group(4.01±0.77)compared to the control group(6.62±0.31)(P<0.05).Similarly,preoperative depression scores were(15.11±1.22)in the observation group and(15.41±2.01)in the control group(P>0.05),but postoperative depression scores were significantly reduced in the observation group(4.24±0.61)compared to the control group(7.12±0.54)(P<0.05).After intervention,the medical compliance behavior index in the observation group was(83.31±5.92),significantly higher than(75.34±6.73)in the control group(P<0.05).Regarding postoperative complications,only 1 case(2.86%)occurred in the observation group,while 8 cases(22.86%)were reported in the control group,showing a statistically significant difference(P<0.05).In conclusion,the medical and nursing integration working mode effectively improves the perioperative psychological state of children,enhances medical compliance,reduces postoperative complications,and is worthy of widespread clinical application.
文摘A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.
基金supported by the National Natural Science Foundation of China(No.52271165)the National Key R&D Program of China(No.2022YFB3505501).
文摘In this paper,the fracture behaviors and interface stresses of sintered Nd-Fe-B magnets were investigated.It was revealed that cracks propagated along the interfaces of Nd_(2)Fe_(14)B/Nd_(2)Fe_(14)B,Nd_(2)Fe_(14)B/Nd-rich phases and within Nd-rich phases.The misfits between 2:14:1 and Nd-rich phases were quantitatively determined,reflecting the concentration of interface stresses in magnet.Grain boundaries of magnet were reconstructed by diffusing Tb-containing and Tb-free sources,respectively.The Tb-rich shells at extensive layers of 2:14:1 grains caused lattice distortion,i.e.,internal stresses,resulting in the crack mode changing from intergranular to transgranular in near surfaces of Tb-containing diffused magnets.Therefore,the bending strengths were deteriorated although the coercivities were apparently enhanced.In the case of Tb-free Pr-Cu diffused magnet,the Pr and Cu elements were enriched at grain boundaries,and the misfits between 2:14:1 and Nd-rich phases were declined,lowering interface stresses and strengthening grain boundaries.The mechanical and magnetic properties of Pr-Cu diffused magnet were simultaneously improved.
基金supported by grants funded by the Hong Kong Research Grants Council(Grant No.CRF/C6006-20G)a grant provided by the Joint NSFC/RGC Joint Research Scheme(Grant No.N_HKUST603/22)the Fundamental Research Funds for the Central Universities(Grant No.Z1090125018).
文摘The effectiveness of using vegetation to stabilise shallow soil slopes heavily depends on the survival of vegetation,yet the amplification of extreme events induced by climate change threatens the health of plants covering slopes.Hydrochar is an environmentally friendly soil amender that can achieve the potential benefits of promoting plant growth for slope stabilisation and facilitation of waste upcycling.The mechanism underlying the hydrochar effects on the mechanical behaviour of unsaturated soils remains unclear.This study investigated the influence of grass-derived hydrochar on the water retention,compressibility,and shear strength of a compacted siltyeclay sand.Soil microstructural changes due to hydrochar amendment were measured to explain the soilehydrochar hydromechanical interaction.The increase in suction resulted in a less significant increase in yield stress and a negligible reduction in compressibility of the hydrochar-amended soil compared with the unamended case.This phenomenon was observed because hydrochar addition reduced the large pores with diameters greater than the macropore peak of 60 mm due to pore filling by hydrochar particles,resulting in a less substantial volume contraction during drying.Hydrochar introduced more significant effects on the soil’s shear strength in an unsaturated state compared to a saturated case.Despite the similarity of the unsaturated amended soil with the critical-state friction angle to the saturated case,the former exhibited a greater shear strength because the hydrochar addition improved water retention capability.As a result,the degree of saturation and,hence,Bishop’s effective stress were higher than those for the unamended case for a given suction.
基金Open Access funding enabled and organized by Projekt DEALfinanced by the Deutsche Forschungsgemeinschaft(DFG)grant 470833544 to WK.
文摘The radula is a crucial adaptation for food-processing in molluscs.A deeper understanding of the interaction between the radula and the preferred food is lacking,complicating the inference of the precise ecological roles of radular structures.This study presents the first experimental set-up that allows to study the influence of the radular morphology,specifically the degree of tooth-tooth interlocking(so-called collective effect),on the feeding efficiency.For this purpose,physical 3D models of the teeth were designed using CAD software and 3D printing technique.The feeding efficiencies with models of different degree of interlocking were determined by tensile tests,pulling the models trough agar gels with different viscosities.The forces generated by the models and the masses of the removed gel fragments were determined.We found,that radular models with a high degree of tooth–tooth interlocking performed best as they were able to remove most agar.We additionally broke the teeth and determined,that the teeth with the highest degree of interlocking could resist to highest force.Overall,the study highlights the complex interplay between radular morphology and its ecological function,suggesting that even minor morphological alterations can significantly impact the efficiency and effectiveness of food gathering.Understanding these interactions cannot only shed light on the ecological adaptations of molluscs,but provide further insights into development of more effective grinding,scraping,and cleaning technical devices.
文摘Glue-laminated timber(GLT)is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties.However,the fire performance of GLT varies significantly due to the natural and uncertain phenomena(moisture,exposure time,isotropic,homogenous properties,etc.)of fire and timber.This makes it difficult to predict the fire behaviour of the GLT structural elements.To ensure building safety,it is crucial to assess GLT’s fire behaviour and post-fire structural integrity during the design stages.This study conducted the experimental tests of GLT beams(280 mm×560 mm)without loading(1.4 m)and under a four-point bending load(5.4 m).Tests identified thermal behaviour and charring rates of GLT beam.Then,the residual stiffness of the GLT beam was calculated,and the charring rates of the beams were compared with Australian and European standards.Reliability analysis was conducted for beams for a fire exposure of 120 min,considering the charring rates observed through the analysis and simulating the fire insulations.Results show that the charring rate of GLT made with spruce pine timber varied between 0.43 and 0.81 mm/min,with a mean rate of 0.7 mm/min,aligning with both Australian and European standards.However,considering timber density and moisture content,the charring rates in Australian standards were conservative.The study also found that structural capacity significantly degrades under fire,with a 22%reduction in flexural stiffness after 120 min of exposure.Additionally,GLT beams can safely function for 30 min under 75%of their design moment capacity and for 60 min under 50%capacity.
文摘Two widespread bird species in Sri Lanka’s dry zone,Pycnonotus cafer(Red-vented Bulbul,RVBB)and Pycnonotus luteolus(White-browed Bulbul,WBBB),were studied to understand their foraging dynamics and ecology.The research was conducted from October 2022 to February 2023 in Mihintale Sanctuary(80.30′11.24″E,8.21′04.63″N)and the Faculty of Applied Sciences,Rajarata University of Sri Lanka(80.502206″E,8.353090″N).Data were obtained through focal sampling,opportunistic observations,and mist netting.Both species predominantly foraged on twigs,using gleaning as the dominant food-handling technique.RVBB foraged mostly at the canopy level,while WBBB foraged primarily at the sub-canopy level.Fruits constituted the major food type for both species.RVBB and WBBB utilized 10 and 7 plant species,respectively,with Grewia helicterifolia being the primary foraging plant.Minimal foraging was observed on Croton sp.(RVBB)and Hugonia mistax(WBBB).The correlation between nutritional components and the consumption of both species revealed a preference for foods with lower protein,higher fat,and ash content.There was no linear correlation between gape width and fruit size(r=-0.21,P=0.69)for both species.The standardized dietary niche breadth indicated both species are specialists,with a high pairwise dietary niche overlap(0.9854).These findings highlight the niche-specific foraging adaptations of RVBB and WBBB within Mihintale,emphasizing their distinct strategies in utilizing plant species,fruit sizes,and foraging heights.Understanding such ecological dynamics is essential for habitat conservation efforts and ensuring the availability of key foraging resources for these species in the dry zone.
文摘Exploring alternative aggregates or recycled aggregates to substitute traditional concrete aggregates,particularly sand aggregates,which are becoming more limited and must comply with environmental protection standards,is essential.Research has explored various alternative materials to sand in concrete,including concrete from demolished buildings,and broken glass from projects,among others.Investigating the use of recycled broken glass to substitute sand aggregates and implementing this research in compression columns is crucial.This paper examines the compressive behavior of reinforced concrete columns that utilize recycled glass particles as a substitute for sand in concrete.The research findings establish the relationships:load and vertical displacement,load and deformation at the column head,mid-column,and column base;the formation and propagation of cracks in the column,while considering factors such as the percentage of recycled glass,the arrangement of stirrups,and the amount of load-bearing steel influencing the performance of square reinforced concrete columns under compression.The feasibility of using recycled glass as a substitute for sand in column structures subjected to compression has been demonstrated,with the ideal replacement content for sand aggregate in reinforced concrete columns in this study ranging from 0%to 10%.The column’s load-bearing ability dropped from 250 kN to 150 kN when 100%recycled glass was used instead of sand.This is a 40%drop,and cracks started to show up sooner.The research will support recycling broken glass instead of using sand in building,improving the environment and reducing natural sand use.
文摘Expansive soils, prone to being influenced by the environmental conditions, undergo expansion when water is introduced and shrinkage upon drying. This persistent volumetric fluctuation can induce differential movements and result in cracking of structures erected upon them. The present research focuses on characterizing the behavior of pavements erected on expansive clays subjected to swelling and shrinkage cycles. Direct shear tests and oedometer tests were conducted in the laboratory on samples of expansive soils undergoing swelling-shrinkage cycles. The experimental data reveal a significant decrease in shear strength, evidenced by a reduction in shear parameters (internal friction angle, cohesion) and a decrease in the modulus of elasticity as the number of cycles increases. A numerical model based on the finite element method was developed to simulate the behavior of a pavement on an expansive clay substrate. The model results indicate an increase in total displacements with the increase in the number of shrinkage-swelling cycles, demonstrating a progressive degradation of the soil’s mechanical behavior. This study contributes to a better understanding of the complex phenomena governing the behavior of expansive soils and serves as a foundation for developing effective management and mitigation strategies for road infrastructures.
基金supported by the Major Research Project of Philosophy and Social Sciences in Universities of Henan Province(2025-JCZD-10)the Natural Science Foundation of Henan Province(242300421311).
文摘This study examined the relationship between leader-employee calling congruence on employees’voice behaviour.Participants were 173 leader-employee dyads from the Chinese service industry.They completed online surveys on calling,perceived insider status,and voice behaviour.Results from polynomial regression and response surface analysis showed that employees perceived insider status to be weaker with the low leader-low subordinate calling congruence,and stronger with high leader and high subordinate calling congruence.Employees perceived insider status is stronger in low leader and high subordinate calling incongruence compared with high leader and low subordinate calling incongruence.Perceived insider status plays a mediating role among calling congruence and voice behaviour.This study’sfindings suggest pathways of calling congruence on voice behaviour,which are important for promoting employee voice behaviour and guiding organisational recruitment in the workplace.
基金supported by the National Natural Science Foundation of China(No.52274344)the Provincial Natural Science Foundation of Hunan(Nos.2022JJ30723 and 2023JJ20068)the Science and Technology Innovation Program of Hunan Province(2023RC3042).
文摘Controlling the adhesion of potentially corrosive substances from flue gas on grate bar is crucial for extending the operational lifespan of the equipment.The adhesive behaviour and mechanism of ultrafine particulate matters(UPM)throughout the sintering process were elucidated,and measures to control adhesion on grate bars were developed.Research findings indicated that a small quantity of UPM were found on grate bar during the initial sintering stages(ignition stage and middle stageⅠandⅡ).The main compositions of UPM were FexOy-rich,CaO-rich,and aluminium silicate-rich particles.In contrast,corrosive substances like alkali metal compounds were almost absent.These UPM adhered onto grate bar primarily through inertial impaction.When moving to the final sintering stages(middle stageⅢand temperature rising stage),many UPM rich in corrosive substances like NaCl and KCl adhered to the grate bar.These UPM adhered to grate bar through thermal diffusion and vortex deposition.Solid waste water washing technology can greatly decrease the quantity of UPM(rich in NaCl and KCl)on the grate bar due to vortex deposition and thermal diffusion,and it represents a potentially promising way to control adhesion and corrosion on grate bars.
文摘This essay evaluates the behavioural dynamics generated by profit incentives and compares them with those in government-owned and charitable enterprises.Drawing on neoclassical microeconomics,agency theory,and institutional economics,it shows how the profit motive drives cost minimization,allocative efficiency,innovation,and consumer responsiveness.Profit expectations,formalized in endogenous growth models,act as catalysts for technological progress and dynamic efficiency,while agency-theoretic governance mechanisms align managerial incentives with shareholder interests.In contrast,government-owned enterprises operate under multi-objective welfare functions,often constrained by soft budget expectations,political interference,and X-inefficiencies that dilute efficiency.Charitable organizations,structured by the non-distribution constraint,emphasize social trust,equity,and mission fulfilment,supported by warm-glow altruism but constrained by free-rider problems and underfunding.A comparative evaluation suggests that profit-driven firms outperform in competitive markets producing private goods,whereas government and charitable forms play essential roles in addressing market failures and providing public or credence goods.The analysis affirms the institutionalist principle that ownership and governance structures must be aligned with the nature of the goods or services delivered.
文摘Background: Waste management in Western Area Rural (WAR), Sierra Leone, is plagued by infrastructural and socioeconomic challenges, leading to environmental and health hazards such as flooding, air pollution, and vector-borne diseases. Despite awareness campaigns, informal methods like open dumping and burning dominate. This study applies the Theory of Planned Behaviour (TPB) to analyse how attitudes, subjective norms, and perceived behavioural control influence waste management practices and barriers to proper disposal with potential solutions. Methods: A quantitative approach was employed, using stratified random sampling and structured questionnaires to collect data from 333 participants across ten communities in Western Area Rural (WAR). Data were analyzed using descriptive and inferential statistics to examine the relationship between socio-demographic variables and waste management practices. Results: While 98.2% of respondents acknowledged the importance of waste management, limited perceived behavioural control driven by financial constraints (83.8%), inadequate education (83.2%), and insufficient infrastructure (66.4%) hindered effective waste disposal ultimately linking health and environmental risks, such as flooding and marine pollution from plastic waste. Most respondents (68.8%) lacked access to formal waste services, with disposal occurring primarily via open dumping (62.9%) and burning (17.9%). Subjective norms reinforced informal disposal, as community waste-burning remained an accepted practice. Women were disproportionately affected due to economic constraints and larger household sizes. Despite these challenges, 93.1% were willing to engage in community clean-up efforts, indicating strong pro-environmental attitudes constrained by structural barriers. Conclusion: Findings underscore the need for integrated waste management strategies informed by TPB, targeting attitudes through education, reshaping social norms through community-driven initiatives, and enhancing perceived behavioural control by improving infrastructure and financial accessibility. Addressing gender disparities, strengthening public-private partnerships, and expanding recycling and composting programs can foster sustainable waste management in resource-constrained settings.
文摘1 Move over Simone Biles,because grey whales might just be the next Olympic champions.This conclusion can be drawn from a new study that filmed these amazing animals doing underwater headstands(头倒立)and other moves.2 As part of a seven-year project,scientists used drones(无人驾驶飞机)to observe a group of 200 grey whales off the coasts of Oregon,Washington,northern California and southern Canada.The new study findings,published in Animal Behaviour,revealed that grey whales do headstands by pressing their mouths against the ocean floor while searching for something to eat.Scientists also noticed that when doing headstands,grey whales move like human synchronized swimmers.
基金financially supported by the National Key Research and Development Program of China(Grant Nos.2023YFB2604005)the National Key Research and Development 451 Program of China(Grant No.2021YFC3100803)the Yangtze River Water Science Research Joint Fund Key Project of National Natural Science Foundation of China(Grant No.U2340231).
文摘Polyurethane foam,when used as a compressible layer in deep soft rock tunnels,offers a feasible solution to reduce the support pressure on the secondary lining.The foam spraying method using sprayed polyurethane material is convenient for engineering applications;however,the compressive behaviour and feasibility of sprayed polyurethane material as a compressible layer remain unclear.To address this gap,this study conducts uniaxial compression tests and scanning electron microscope(SEM)tests to investigate the compressive behaviour of the rigid foams fabricated from a self-developed polyurethane spray material.A peridynamics model for the composite lining with a polyurethane compressible layer is then established.After validating the proposed method by comparison with two tests,a parametric study is carried out to investigate the damage evolution of the composite lining with a polyurethane compressible layer under various combinations of large deformations and compressible layer parameters.The results indicate that the polyurethane compressible layer effectively reduces the radial deformation and damage index of the secondary lining while increasing the damage susceptibility of the primary lining.The thickness of the polyurethane compressible layer significantly influences the prevention effect of large deformation-induced damage to the secondary lining within the density range of 50e100 kg/m^(3).In accordance with the experimental and simulation results,a simple,yet reasonable and convenient approach for determining the key parameters of the polyurethane compressible layer is proposed,along with a classification scheme for the parameters of the polyurethane compressible layer.
文摘Rolling noise is an important source of railway noise and depends also on the dynamic behaviour of a railway track.This is characterized by the point or transfer mobility and the track decay rate,which depend on a number of track parameters.One possible reason for deviations between simulated and measured results for the dynamic track behaviour is the uncertainty of the value of some track parameters used as input for the simulation.This in turn results in an uncertainty in the simulation results.In this contribution,it is proposed to use the general transformation method to assess a uncertainty band for the results.Most relevant input parameters for determining the point input mobility and the track decay rate for a ballasted track are analysed with regard to the uncertainties and for the value of each an interval is determined.Then,the general transformation method is applied to four different simulation methods,working both in the frequency and time domains.For one example track,the resulting uncertainty bands are compared to one dataset with measurements for the point mobility and the track decay rate.In addition,a sensitivity analysis is performed to determine the parameters that significantly influence the overall result.While all four simulation methods produce broad uncertainty bands for the results,none did match the measured results for the point mobility and the track decay rate over the entire frequency range considered.Besides the large influence of the uncertain pad stiffness,it turned out that the rail wear is also a significant source of uncertainty of the results.Overall,it is demonstrated that the proposed approach allows assessing the influence of uncertain input parameters in detail.
基金supported by the National Natural Science Foundation of China(No.22090041)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2017ZT07C069)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2022B1515120014)the Natural Science Foundation of Zhejiang Province(No.LQ21A040010).
文摘The exploratory synthesis and structural characterization of twodimensional(2D)honeycomb structured Ru-based compounds are key focuses in inorganic materials research,due to the various exotic electronic states arising from the interplay of electron correlations and spinorbit coupling.Among these compounds,α-RuCl_(3) and RuBr_(3) are considered as the most promising candidates for quantum spin liquid(QSL)materials[1–3].As a homolog,α-RuI3 has attracted significant interest,but it still remains relatively unexplored.Recently,it was synthesized by high-temperature and high-pressure solid-state reaction,but reported to be different crystal structures by independent groups.Ni et al.and Nawa et al.considerα-RuI3 to be R-3(3R)and P-31c(2H)space group,respectively[4,5].Both structures have typical 2D characteristics,in which the edge-sharing RuI6 octahedra form honeycomb layers stacked along the c-axis.The primary difference lies in that the honeycomb layers stack in ABCABC mode in the 3R phase,while in ABAB mode in the 2H phase(Fig.S1).Yang et al.discussed the stability of 3R and 2H polymorphs in terms of the total energies and dynamics,finding both structures are stable.However,the total energy of the 2H phase is slightly higher,2.58 meV than that of the 3R analog[6].When it comes to the conductivity behaviour,α-RuCl3 andα-RuBr_(3) are semiconductors as normally observed in QSL materials.In contrast,α-RuI_(3) exhibits metallic response.In 2D materials,the band structure may be drastically modified by altering the stacking order[7].Hence,determining the crystal structure ofα-RuI_(3) is urgently required,which is a key step in comprehensive and in-depth analysis of its physical properties.
