Objectives This study aimed to explore the lagged and cumulative effects of risk factors on disability in older adults using distributed lag non-linear models(DLNMs).Methods We utilized data from the China Health and ...Objectives This study aimed to explore the lagged and cumulative effects of risk factors on disability in older adults using distributed lag non-linear models(DLNMs).Methods We utilized data from the China Health and Retirement Longitudinal Study(CHARLS).After feature selection via Elastic Net Regularization,we applied DLNMs to evaluate the lagged effects of risk factors.Disability was defined as the presence of any difficulties in basic activities of daily living(BADL).The cumulative relative risk(CRR)was calculated by summing the lag-specific risk estimates,representing the cumulative disability risk over the specified lag period.Effect modifications and sensitivity analyses were also performed.Results This study included a total of 2,318 participants.Early-phase lag factors,such as the difficulty in stooping(CRR=3.58;95%CI:2.31-5.55;P<0.001)and walking(CRR=2.77;95%CI:1.39-5.55;P<0.001),exerted the strongest effects immediately upon occurrence.Mid-phase lag factors,such as arthritis(CRR=1.51;95%CI:1.10-2.06;P=0.001),showed a resurgence in disability risk within 2-3 years.Late-phase lag factors,including depressive symptoms(CRR=2.38;95%CI:1.30-4.35;P<0.001)and elevated systolic blood pressure(CRR=1.64;95%CI:1.06-2.79;P=0.02),exhibited significant long-term cumulative risks.Conversely,grip strength(CRR=0.80;95%CI:0.54-0.95;P=0.02)and social participation(CRR=0.89;95%CI:0.73-0.99;P=0.04)were significant protective factors.Conclusions The findings underscore the importance of tailored interventions that account for various lag characteristics of different factors to effectively mitigate disability risk.Future studies should explore the underlying biological and sociological mechanisms of these lagged effects,identify intervention strategies that target risk factors with different lagged patterns,and evaluate their effectiveness.展开更多
Globally,mealtimes provide key insights into cultural and social values and practices.We examine mealtime environments and eating practices in two different African settings using quantitative observational and questi...Globally,mealtimes provide key insights into cultural and social values and practices.We examine mealtime environments and eating practices in two different African settings using quantitative observational and questionnaire data.Participating families(N=80)were recruited from two rural locations in Zambia and Kenya.Results following descriptive analysis showed that meals are typically taken as a family in a sociable context,providing opportunities to nurture children’s positive behaviours.In both communities,mothers(71.25%)were most likely to be present and typically prepared meals and provided the food.We observed a few distractions being used during mealtimes,and children finished their food with little to no conflict.Plate sharing varied across the two sites and was more common in Zambia,where we also observed more traditional practices such as eating with hands(as opposed to cutlery)and sitting on mats on the ground(as opposed to seated on chairs or sofas).Overall,our findings suggest more similarities in the cultural and social values across the two African contexts despite slight differences in mealtime practices.In particular,positive mealtime behaviours(little food refusal,lack of conflict)were common across all contexts,regardless of the extent to which traditional practices(such as plate-sharing and sitting on the floor)were used.Findings align with Family Systems theory,which states that the family is understood best by conceptualizing it as a complex,dynamic,and changing collection of parts,subsystems,and family members.展开更多
Although various Climate-Smart Agricultural(CSA) practices are promoted to safeguard agricultural production and food security in the Global South,their adoption remains limited.This study conducted a cross-sectional ...Although various Climate-Smart Agricultural(CSA) practices are promoted to safeguard agricultural production and food security in the Global South,their adoption remains limited.This study conducted a cross-sectional survey using a semi-structured questionnaire between March and April in 2023,with a sample of 231 smallholder farmers covering 5 villages(Purbo Karpara,Rampasa,Monohor Pur,Boro Isubpur,and Char Alapur) in Haor wetlands of Bangladesh.Then,this study examined smallholder farmers' adoption intention of floating farming practice in Haor wetlands of Bangladesh based on an extended Theory of Planned Behaviour(TPB) model.The result demonstrated moderate predictive power of the proposed model,where farmers' attitude,subjective norm,knowledge of floating farming practice,perceived behavioural control,and institutional accessibility jointly explained 11.50% of the total variance in adoption intention,with subjective norm and perceived behavioural control showing significant impact on smallholder farmers' adoption intention.However,key barriers reported by smallholder farmers included unavailability of resources,limited access to modern farming practices,input and credit unavailability,insufficient access to training,and limited access to market system.These findings indicated that improving smallholder farmers' access to extension services and credit facilities,raising awareness,providing training,and guaranteeing access to accurate and timely climate information and early warning systems could significantly improve their adaptive capacity.This study contributes to socio-psychological understanding of smallholder farmers' pro-environmental behaviour and emphasises the need for context-specific interventions to support sustainable livelihoods and resilient agri-food systems in climate-vulnerable regions.展开更多
The goal of this work is to investigate the seismic behaviour of plan-asymmetric structures by considering the least seismic-resistant directions and the spatial features of the seismic event. New tools for the analys...The goal of this work is to investigate the seismic behaviour of plan-asymmetric structures by considering the least seismic-resistant directions and the spatial features of the seismic event. New tools for the analysis of the seismic behaviour of plan-asymmetric structures are herein presented and the concepts of ＂Polar Spectrum＂ and limit domains are discussed. In particular, the capacity of the structure is described by using the limit domains based on the Non Linear Static Procedures, while the seismic demand is analysed by introducing a new representation of the spectral response. This representation is based on the construction of a spectral surface obtained by the spectral seismic response for different in-plan directions and the in-plan projection of this surface is herein defined ＂Polar Spectrum＂. The obtained results for two benchmark structures, verified by means of non-linear incremental dynamic analyses, have pointed out that non-linear static analyses, carried out for different in-plan directions of the incoming seismic action, have allowed us to accurately evaluate the least seismic resistant directions.展开更多
To enhance the anti-corrosion performance of TC4 alloy across a wide temperature range for modern aircrafts operating in increasingly harsh environments, the (TiB+TiC) hybrid reinforced TC4 composites were prepared by...To enhance the anti-corrosion performance of TC4 alloy across a wide temperature range for modern aircrafts operating in increasingly harsh environments, the (TiB+TiC) hybrid reinforced TC4 composites were prepared by laser melting deposition (LMD) via the in-situ reaction between B_(4)C reinforcement and molten TC4 alloy. The effect of B_(4)C content (0, 0.5, 1.5, wt%) on the microstructure and room/high-temperature corrosion behaviour of the composites was investigated. Microstructural analysis revealed that the microstructure of the composites was significantly influenced by the B_(4)C content. The composite containing 0.5 wt% B_(4)C exhibited an optimal microstructure characterized by refined grains, equiaxed α-Ti transformed from lath-shaped α-Ti, well-distributed (TiB+TiC) phases with a proper amount and reduced pore/dislocation defects. This composite also demonstrated the best corrosion resistance at both room temperature (25 ℃) and high temperature (800 ℃), which was primarily attributed to its comprehensive advantages including a favorable microstructure, a uniform dispersion of thermally stable (TiB+TiC) phases and a stable passivation film.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
AlSi7Mg is an age hardening aluminium alloy that is growing in popularity in additive manufacturing as its good processability makes it well suited to the powder bed fusion process,allowing for its use in the aerospac...AlSi7Mg is an age hardening aluminium alloy that is growing in popularity in additive manufacturing as its good processability makes it well suited to the powder bed fusion process,allowing for its use in the aerospace and automotive industries.The alloy relies on heat treatment to reach its peak strength,with precipitates in the Mg_(2) Si precipitation sequence providing the majority of this strengthening.Powder bed fusion,however,produces components with unique microstructures that differ to those of traditional manufacturing methods such as casting,meaning heat treatments must be carefully tailored for additively manufactured parts.This study therefore investigated the effects of solution treatment temperatures on the final properties and microstructures of T6 treated,additively manufactured AlSi7Mg.Due to the use of a heated build plate,samples aged from the as built and stress relieved conditions exhibited over ageing behaviour,necessitating a solution treatment step to induce useful strength properties.Solution treatments below 500℃were found to provide minimal strengthening upon ageing due to the pres-ence of theπ-Al_(18) Fe_(2)Mg_(7) Si_(10) phase,which reduced the amount of magnesium in solid solution and so reduced the age hardening response of the alloy by restricting the growth of strengthening precipitates.Solution treatments over 500℃,however,demonstrated excellent age hardening due to the replacement of theπ-Al_(18) Fe_(2)Mg_(7) Si_(10) phase with theβ-Al_(9)Fe_(2)Si_(2) phase,increasing the concentration of magnesium in solid solution and therefore improving its age hardening response.A T6 treatment then demonstrated an improvement in yield strength and ductility when compared to the as built state,but a decrease in tensile strength and impact toughness.The variability in the age hardening response of AlSi7Mg suggests that the careful selection of a solution treatment temperature is crucial to property optimisation.展开更多
Background Attention-deficit/hyperactivity disorder(ADHD)is a common neurodevelopmental disorder with behavioural symptoms and grey matter volume(GMV)changes.However,previous studies have not fully elucidated the prog...Background Attention-deficit/hyperactivity disorder(ADHD)is a common neurodevelopmental disorder with behavioural symptoms and grey matter volume(GMV)changes.However,previous studies have not fully elucidated the progressive and causal GMV changes associated with behavioural symptoms in ADHD.Aims This study aimed to explore the causal relationship between GMV alterations and behavioural symptoms in children and adolescents with ADHD using behaviourcausal structural covariance network(BCaSCN)analysis.Methods Structural magnetic resonance imaging(sMRI)data from 135 children and adolescents with ADHD and182 neurotypical controls(NCs)were analysed.ADHD subtypes were identified based on GMV using a clustering algorithm to address the neuroanatomical heterogeneity.To investigate the causal relationships of GMV changes related to behavioural symptoms,sMRI data were sequentially ordered by ADHD index,inattentive index and hyperactive/impulsive index values to generate pseudotime series data.These data were then analysed using region-of-interest-based BCaSCN analysis to explore potential progressive patterns of GMV change.Results Neuroanatomical subtyping revealed two ADHD subtypes with distinct GMV patterns compared with NCs.BCaSCN analysis showed that ADHD subtype 1 was closely associated with inattentiveness,involving prominent nodes in the frontal regions and cerebellum.In contrast,ADHD subtype 2 was more strongly linked to overall disease severity,with the cerebellum and hippocampus as primary hubs.Conclusions ADHD is associated with heterogeneous changes in GMV corresponding to distinct behavioural domains,highlighting the need for subtype-specific diagnostic and therapeutic strategies.展开更多
This opinion article discusses the original research work of Yünkül et al.(the Authors)published in the Journal of Mountain Science 21(9):3108–3122.Employing non-linear regression,fuzzy logic and artificial...This opinion article discusses the original research work of Yünkül et al.(the Authors)published in the Journal of Mountain Science 21(9):3108–3122.Employing non-linear regression,fuzzy logic and artificial neural network modeling techniques,the Authors interrogated a large database assembled from the existing research literature to assess the performance of twelve equation rules in predicting the undrained shear strength(s_(u))mobilized for remolded fine-grained soils at different values of liquidity index(I_(L))and water content ratio.Based on their analyses,the Authors proposed a simple and reportedly reliable correlation(i.e.,Eq.9 in their paper)for predicting s_(u) over the I_(L) range of 0.15 to 3.00.This article describes various shortcomings in the Authors’assembled database(including potentially anomalous data and covering an excessively wide I_(L) range in relation to routine geotechnical and transportation engineering applications)and their proposed s_(u)=f(I_(L))correlation.Contrary to the Authors’assertions,their proposed correlation is not reliable for fine-grained soils with consistencies in the general firm to stiff range(i.e.,for 0.15<I_(L)<0.40),increasingly overestimating s_(u) for reducing I_(L),and eventually predicting s_(u)→+∞for I_(L)→0.15+(while producing mathematically undefined s_(u) for I_(L)<0.15),thus rendering their correlation unconservative and potentially leading to unsafe geotechnical designs.Exponential or regular-power type s_(u)=f(I_(L))models are more s_(u)itable when developing correlations that are applicable over the full plastic range(of 0<I_(L)<1),thereby providing reasonably conservative s_(u) predictions for use in the preliminary design for routine geotechnical engineering applications.展开更多
Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force an...Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force and contact area.However,the real contact area fraction should never equal one;there must be a limit smaller than the apparent area,implying that the real contact area cannot increase linearly indefinitely.In this paper,the real contact area between two polymethylmethacrylate(PMMA)blocks under heavy load is measured using the total reflection method,and the contact area is analyzed using the image processing method.The results show that the real contact area increases with normal load linearly in light loads but non-linearly in heavy loads;the number of contact spots increases with load linearly in light loads but also non-linearly in heavy loads,synchronous with the change in the real contact area.The GW,MB,and Zhao,Maietta,and Chang(ZMC)models were used to predict the experiment results,but none of them predicted the non-linear stage.A revised GW model based on the bulk deformation hypothesis performs better in predicting the non-linear stage.The study’s findings can be applied to PMMA or other similar materials,and they can serve as a useful reference for future research on the contact mechanisms of other materials.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
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
Background The decreasing prevalence of physical activity(PA)among urban children in Sub-Saharan Africa is a growing public health concern.More emphasis should focus on examining the influence of parental PA behaviour...Background The decreasing prevalence of physical activity(PA)among urban children in Sub-Saharan Africa is a growing public health concern.More emphasis should focus on examining the influence of parental PA behaviour on the children’s PA patterns.We explored associations of 24hour(h)accelerometer-measured movement behaviours of guardian-child pairs in Nairobi City County,Kenya.Methods This cross-sectional study assessed 80 pairs consisting of children aged 9-14 years and their guardians in one area of low and one area of middle socioeconomic status(SES)(Embakasi Sub-County and Lang’ata Sub-County),in Nairobi City County,Kenya.The study used waist worn Tri-axial Actigraph(GT3X+and ActiSleep+)accelerometers to quantify PA and sedentary time(SED).Association between guardians'and children’s PA was examined using linear regression,adjusting for guardians'educational attainment and household wealth.Results Of the children,42(52.5%)and 76(96.2%)of the guardians were women.Children in low SES areas spent more time(p<0.001)in moderate-to-vigorous physical activity compared to children from middle SES area.The guardians in low SES area were younger and spent more time in light PA(p=0.036)while their counterparts had higher daily SED(p=0.049).Guardian’s SED associated with higher children’s SED(p=0.033)even after adjusting for guardians'educational attainment(p=0.032)and wealth(p=0.05).There was no association between guardians'and children’s MVPA.Conclusion Considered alongside the extant literature,these results suggest that health promotion strategies should aim to reduce parental SED time while also planning to increase children’s PA.展开更多
Organisms have evolved a strain limiting mechanism,reflected as a non-linear elastic constitutive,to prevent large deformations from threatening soft tissue integrity.Compared with linear elastic substrates,the wrinkl...Organisms have evolved a strain limiting mechanism,reflected as a non-linear elastic constitutive,to prevent large deformations from threatening soft tissue integrity.Compared with linear elastic substrates,the wrinkle of films on non-linear elastic substrates has received less attention.In this article,a unique wrinkle evolution of the film-substrate system with a J-shaped non-linear stress-strain relation is reported.The result shows that a concave hexagonal array pattern is formed with the shrinkage strain of the film-substrate systems developing.As the interconnection of hexagonal arrays,a unit cell ridge network appears with properties such as chirality and helix.The subparagraph maze pattern formed with high compression is mainly composed of special single-cell ridge networks such as spiral single cores,chiral double cores,and combined multi-cores.This evolutionary model is highly consistent with the results of experiments,and it also predicts wrinkle morphology that has not yet been reported.These findings can serve as a novel explanation for the surface wrinkle of biological soft tissue,as well as provide references for the preparation of artificial biomaterials and programmable soft matter.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
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 coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)affected health,economies,and lifestyles,but little is known about its impact on children.We aimed to...The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)affected health,economies,and lifestyles,but little is known about its impact on children.We aimed to investigate changes in 24-hour(h)movement behaviours of pre-school children before and during COVID-19,and factors that influenced these.Children aged 3-6 years were recruited in Beijing in 2019,and their movement behaviours over 24h assessed by questionnaire,as part of the International Study of Movement Behaviors in the Early Years(SUNRISE)study.We conducted the survey again during COVID-19,and compared the children’s movement behaviours before and during COVID-19 and associated factors.Overall,196 parents completed the survey at both time points.The percentage of children meeting movement guidelines decreased during the pandemic(p<0.01).Total physical activity decreased less among children getting good quality sleep or with more adults in the household(p<0.01).Children who were not cared for primarily by their mother had a greater decrease in moderate to vigorous intensity physical activity(p=0.02),but the decrease was smaller among children whose parents used the internet to support their physical activity and/or screen time(p<0.05).Children who used electronic screen devices in the 2h before bedtime or whose parents reported body temperature in webchats had a greater increase in sedentary screen time(p<0.05).Children spending more time outdoors showed a smaller decrease in sleep(p<0.01).Overall,children’s movement behaviours changed significantly during the pandemic.展开更多
Laser debonding technology has been widely used in advanced chip packaging,such as fan-out integration,2.5D/3D ICs,and MEMS devices.Typically,laser debonding of bonded pairs(R/R separation)is typically achieved by com...Laser debonding technology has been widely used in advanced chip packaging,such as fan-out integration,2.5D/3D ICs,and MEMS devices.Typically,laser debonding of bonded pairs(R/R separation)is typically achieved by completely removing the material from the ablation region within the release material layer at high energy densities.However,this R/R separation method often results in a significant amount of release material and carbonized debris remaining on the surface of the device wafer,severely reducing product yields and cleaning efficiency for ultra-thin device wafers.Here,we proposed an interfacial separation strategy based on laser-induced hot stamping effect and thermoelastic stress wave,which enables stress-free separation of wafer bonding pairs at the interface of the release layer and the adhesive layer(R/A separation).By comprehensively analyzing the micro-morphology and material composition of the release material,we elucidated the laser debonding behavior of bonded pairs under different separation modes.Additionally,we calculated the ablation threshold of the release material in the case of wafer bonding and established the processing window for different separation methods.This work offers a fresh perspective on the development and application of laser debonding technology.The proposed R/A interface separation method is versatile,controllable,and highly reliable,and does not leave release materials and carbonized debris on device wafers,demonstrating strong industrial adaptability,which greatly facilitates the application and development of advanced packaging for ultra-thin chips.展开更多
基金supported by ScientificResearch Fund of National Health Commission of the People’s Republic of China-Major Science and Technology Program for Medicine and Health in Zhejiang Province(WKJ-ZJ-2406).
文摘Objectives This study aimed to explore the lagged and cumulative effects of risk factors on disability in older adults using distributed lag non-linear models(DLNMs).Methods We utilized data from the China Health and Retirement Longitudinal Study(CHARLS).After feature selection via Elastic Net Regularization,we applied DLNMs to evaluate the lagged effects of risk factors.Disability was defined as the presence of any difficulties in basic activities of daily living(BADL).The cumulative relative risk(CRR)was calculated by summing the lag-specific risk estimates,representing the cumulative disability risk over the specified lag period.Effect modifications and sensitivity analyses were also performed.Results This study included a total of 2,318 participants.Early-phase lag factors,such as the difficulty in stooping(CRR=3.58;95%CI:2.31-5.55;P<0.001)and walking(CRR=2.77;95%CI:1.39-5.55;P<0.001),exerted the strongest effects immediately upon occurrence.Mid-phase lag factors,such as arthritis(CRR=1.51;95%CI:1.10-2.06;P=0.001),showed a resurgence in disability risk within 2-3 years.Late-phase lag factors,including depressive symptoms(CRR=2.38;95%CI:1.30-4.35;P<0.001)and elevated systolic blood pressure(CRR=1.64;95%CI:1.06-2.79;P=0.02),exhibited significant long-term cumulative risks.Conversely,grip strength(CRR=0.80;95%CI:0.54-0.95;P=0.02)and social participation(CRR=0.89;95%CI:0.73-0.99;P=0.04)were significant protective factors.Conclusions The findings underscore the importance of tailored interventions that account for various lag characteristics of different factors to effectively mitigate disability risk.Future studies should explore the underlying biological and sociological mechanisms of these lagged effects,identify intervention strategies that target risk factors with different lagged patterns,and evaluate their effectiveness.
基金funded by UKRI Global Challenges Research Fund through the Economic and Social Research Council(grant reference:ES/T004959/1)with additional partial support from the National Research Foundation of South Africa(grant CSUR230503101533)。
文摘Globally,mealtimes provide key insights into cultural and social values and practices.We examine mealtime environments and eating practices in two different African settings using quantitative observational and questionnaire data.Participating families(N=80)were recruited from two rural locations in Zambia and Kenya.Results following descriptive analysis showed that meals are typically taken as a family in a sociable context,providing opportunities to nurture children’s positive behaviours.In both communities,mothers(71.25%)were most likely to be present and typically prepared meals and provided the food.We observed a few distractions being used during mealtimes,and children finished their food with little to no conflict.Plate sharing varied across the two sites and was more common in Zambia,where we also observed more traditional practices such as eating with hands(as opposed to cutlery)and sitting on mats on the ground(as opposed to seated on chairs or sofas).Overall,our findings suggest more similarities in the cultural and social values across the two African contexts despite slight differences in mealtime practices.In particular,positive mealtime behaviours(little food refusal,lack of conflict)were common across all contexts,regardless of the extent to which traditional practices(such as plate-sharing and sitting on the floor)were used.Findings align with Family Systems theory,which states that the family is understood best by conceptualizing it as a complex,dynamic,and changing collection of parts,subsystems,and family members.
基金Ghent University,Belgium,for providing the research support for this study。
文摘Although various Climate-Smart Agricultural(CSA) practices are promoted to safeguard agricultural production and food security in the Global South,their adoption remains limited.This study conducted a cross-sectional survey using a semi-structured questionnaire between March and April in 2023,with a sample of 231 smallholder farmers covering 5 villages(Purbo Karpara,Rampasa,Monohor Pur,Boro Isubpur,and Char Alapur) in Haor wetlands of Bangladesh.Then,this study examined smallholder farmers' adoption intention of floating farming practice in Haor wetlands of Bangladesh based on an extended Theory of Planned Behaviour(TPB) model.The result demonstrated moderate predictive power of the proposed model,where farmers' attitude,subjective norm,knowledge of floating farming practice,perceived behavioural control,and institutional accessibility jointly explained 11.50% of the total variance in adoption intention,with subjective norm and perceived behavioural control showing significant impact on smallholder farmers' adoption intention.However,key barriers reported by smallholder farmers included unavailability of resources,limited access to modern farming practices,input and credit unavailability,insufficient access to training,and limited access to market system.These findings indicated that improving smallholder farmers' access to extension services and credit facilities,raising awareness,providing training,and guaranteeing access to accurate and timely climate information and early warning systems could significantly improve their adaptive capacity.This study contributes to socio-psychological understanding of smallholder farmers' pro-environmental behaviour and emphasises the need for context-specific interventions to support sustainable livelihoods and resilient agri-food systems in climate-vulnerable regions.
文摘The goal of this work is to investigate the seismic behaviour of plan-asymmetric structures by considering the least seismic-resistant directions and the spatial features of the seismic event. New tools for the analysis of the seismic behaviour of plan-asymmetric structures are herein presented and the concepts of ＂Polar Spectrum＂ and limit domains are discussed. In particular, the capacity of the structure is described by using the limit domains based on the Non Linear Static Procedures, while the seismic demand is analysed by introducing a new representation of the spectral response. This representation is based on the construction of a spectral surface obtained by the spectral seismic response for different in-plan directions and the in-plan projection of this surface is herein defined ＂Polar Spectrum＂. The obtained results for two benchmark structures, verified by means of non-linear incremental dynamic analyses, have pointed out that non-linear static analyses, carried out for different in-plan directions of the incoming seismic action, have allowed us to accurately evaluate the least seismic resistant directions.
基金supported by the Tianjin Municipal Natural Science Foundation(No.23JCYBJC00040)the National Nat-ural Science Foundation of China(No.52175369)the Tian-jin Research Innovation Project for Postgraduate Students(No.2022SKY134).
文摘To enhance the anti-corrosion performance of TC4 alloy across a wide temperature range for modern aircrafts operating in increasingly harsh environments, the (TiB+TiC) hybrid reinforced TC4 composites were prepared by laser melting deposition (LMD) via the in-situ reaction between B_(4)C reinforcement and molten TC4 alloy. The effect of B_(4)C content (0, 0.5, 1.5, wt%) on the microstructure and room/high-temperature corrosion behaviour of the composites was investigated. Microstructural analysis revealed that the microstructure of the composites was significantly influenced by the B_(4)C content. The composite containing 0.5 wt% B_(4)C exhibited an optimal microstructure characterized by refined grains, equiaxed α-Ti transformed from lath-shaped α-Ti, well-distributed (TiB+TiC) phases with a proper amount and reduced pore/dislocation defects. This composite also demonstrated the best corrosion resistance at both room temperature (25 ℃) and high temperature (800 ℃), which was primarily attributed to its comprehensive advantages including a favorable microstructure, a uniform dispersion of thermally stable (TiB+TiC) phases and a stable passivation film.
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AlSi7Mg is an age hardening aluminium alloy that is growing in popularity in additive manufacturing as its good processability makes it well suited to the powder bed fusion process,allowing for its use in the aerospace and automotive industries.The alloy relies on heat treatment to reach its peak strength,with precipitates in the Mg_(2) Si precipitation sequence providing the majority of this strengthening.Powder bed fusion,however,produces components with unique microstructures that differ to those of traditional manufacturing methods such as casting,meaning heat treatments must be carefully tailored for additively manufactured parts.This study therefore investigated the effects of solution treatment temperatures on the final properties and microstructures of T6 treated,additively manufactured AlSi7Mg.Due to the use of a heated build plate,samples aged from the as built and stress relieved conditions exhibited over ageing behaviour,necessitating a solution treatment step to induce useful strength properties.Solution treatments below 500℃were found to provide minimal strengthening upon ageing due to the pres-ence of theπ-Al_(18) Fe_(2)Mg_(7) Si_(10) phase,which reduced the amount of magnesium in solid solution and so reduced the age hardening response of the alloy by restricting the growth of strengthening precipitates.Solution treatments over 500℃,however,demonstrated excellent age hardening due to the replacement of theπ-Al_(18) Fe_(2)Mg_(7) Si_(10) phase with theβ-Al_(9)Fe_(2)Si_(2) phase,increasing the concentration of magnesium in solid solution and therefore improving its age hardening response.A T6 treatment then demonstrated an improvement in yield strength and ductility when compared to the as built state,but a decrease in tensile strength and impact toughness.The variability in the age hardening response of AlSi7Mg suggests that the careful selection of a solution treatment temperature is crucial to property optimisation.
基金funded by the Department of Science and Technology of Shandong ProvinceNatural Science Foundation of Shandong Province(ZR2023QH109)Taishan Scholars Program of Shandong Province(TS201712065)。
文摘Background Attention-deficit/hyperactivity disorder(ADHD)is a common neurodevelopmental disorder with behavioural symptoms and grey matter volume(GMV)changes.However,previous studies have not fully elucidated the progressive and causal GMV changes associated with behavioural symptoms in ADHD.Aims This study aimed to explore the causal relationship between GMV alterations and behavioural symptoms in children and adolescents with ADHD using behaviourcausal structural covariance network(BCaSCN)analysis.Methods Structural magnetic resonance imaging(sMRI)data from 135 children and adolescents with ADHD and182 neurotypical controls(NCs)were analysed.ADHD subtypes were identified based on GMV using a clustering algorithm to address the neuroanatomical heterogeneity.To investigate the causal relationships of GMV changes related to behavioural symptoms,sMRI data were sequentially ordered by ADHD index,inattentive index and hyperactive/impulsive index values to generate pseudotime series data.These data were then analysed using region-of-interest-based BCaSCN analysis to explore potential progressive patterns of GMV change.Results Neuroanatomical subtyping revealed two ADHD subtypes with distinct GMV patterns compared with NCs.BCaSCN analysis showed that ADHD subtype 1 was closely associated with inattentiveness,involving prominent nodes in the frontal regions and cerebellum.In contrast,ADHD subtype 2 was more strongly linked to overall disease severity,with the cerebellum and hippocampus as primary hubs.Conclusions ADHD is associated with heterogeneous changes in GMV corresponding to distinct behavioural domains,highlighting the need for subtype-specific diagnostic and therapeutic strategies.
文摘This opinion article discusses the original research work of Yünkül et al.(the Authors)published in the Journal of Mountain Science 21(9):3108–3122.Employing non-linear regression,fuzzy logic and artificial neural network modeling techniques,the Authors interrogated a large database assembled from the existing research literature to assess the performance of twelve equation rules in predicting the undrained shear strength(s_(u))mobilized for remolded fine-grained soils at different values of liquidity index(I_(L))and water content ratio.Based on their analyses,the Authors proposed a simple and reportedly reliable correlation(i.e.,Eq.9 in their paper)for predicting s_(u) over the I_(L) range of 0.15 to 3.00.This article describes various shortcomings in the Authors’assembled database(including potentially anomalous data and covering an excessively wide I_(L) range in relation to routine geotechnical and transportation engineering applications)and their proposed s_(u)=f(I_(L))correlation.Contrary to the Authors’assertions,their proposed correlation is not reliable for fine-grained soils with consistencies in the general firm to stiff range(i.e.,for 0.15<I_(L)<0.40),increasingly overestimating s_(u) for reducing I_(L),and eventually predicting s_(u)→+∞for I_(L)→0.15+(while producing mathematically undefined s_(u) for I_(L)<0.15),thus rendering their correlation unconservative and potentially leading to unsafe geotechnical designs.Exponential or regular-power type s_(u)=f(I_(L))models are more s_(u)itable when developing correlations that are applicable over the full plastic range(of 0<I_(L)<1),thereby providing reasonably conservative s_(u) predictions for use in the preliminary design for routine geotechnical engineering applications.
基金Supported by National Natural Science Foundation of China(Grant No.11872033)Beijing Municipal Natural Science Foundation(Grant No.3172017)。
文摘Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force and contact area.However,the real contact area fraction should never equal one;there must be a limit smaller than the apparent area,implying that the real contact area cannot increase linearly indefinitely.In this paper,the real contact area between two polymethylmethacrylate(PMMA)blocks under heavy load is measured using the total reflection method,and the contact area is analyzed using the image processing method.The results show that the real contact area increases with normal load linearly in light loads but non-linearly in heavy loads;the number of contact spots increases with load linearly in light loads but also non-linearly in heavy loads,synchronous with the change in the real contact area.The GW,MB,and Zhao,Maietta,and Chang(ZMC)models were used to predict the experiment results,but none of them predicted the non-linear stage.A revised GW model based on the bulk deformation hypothesis performs better in predicting the non-linear stage.The study’s findings can be applied to PMMA or other similar materials,and they can serve as a useful reference for future research on the contact mechanisms of other materials.
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.
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funded by the Finnish Ministry of Foreign Affairs through the Higher Education Institutions Institutional Cooperation Instrument,grant no.HEL7M0453-82(https://www.oph.fi/en/programmes/hei-ici-programme).
文摘Background The decreasing prevalence of physical activity(PA)among urban children in Sub-Saharan Africa is a growing public health concern.More emphasis should focus on examining the influence of parental PA behaviour on the children’s PA patterns.We explored associations of 24hour(h)accelerometer-measured movement behaviours of guardian-child pairs in Nairobi City County,Kenya.Methods This cross-sectional study assessed 80 pairs consisting of children aged 9-14 years and their guardians in one area of low and one area of middle socioeconomic status(SES)(Embakasi Sub-County and Lang’ata Sub-County),in Nairobi City County,Kenya.The study used waist worn Tri-axial Actigraph(GT3X+and ActiSleep+)accelerometers to quantify PA and sedentary time(SED).Association between guardians'and children’s PA was examined using linear regression,adjusting for guardians'educational attainment and household wealth.Results Of the children,42(52.5%)and 76(96.2%)of the guardians were women.Children in low SES areas spent more time(p<0.001)in moderate-to-vigorous physical activity compared to children from middle SES area.The guardians in low SES area were younger and spent more time in light PA(p=0.036)while their counterparts had higher daily SED(p=0.049).Guardian’s SED associated with higher children’s SED(p=0.033)even after adjusting for guardians'educational attainment(p=0.032)and wealth(p=0.05).There was no association between guardians'and children’s MVPA.Conclusion Considered alongside the extant literature,these results suggest that health promotion strategies should aim to reduce parental SED time while also planning to increase children’s PA.
基金This work was supported by the Youth Project of Hunan Provincial Department of Education(Grant No.22B0334)the Bridge and Tunnel Engineering Innovation Project of Changsha University of Science&Technology(Grant No.11ZDXK11)and the Practical Innovation and Entrepreneurship Capacity Improvement Plan of Changsha University of Science and Technology(Grant No.CLSJCX23029).
文摘Organisms have evolved a strain limiting mechanism,reflected as a non-linear elastic constitutive,to prevent large deformations from threatening soft tissue integrity.Compared with linear elastic substrates,the wrinkle of films on non-linear elastic substrates has received less attention.In this article,a unique wrinkle evolution of the film-substrate system with a J-shaped non-linear stress-strain relation is reported.The result shows that a concave hexagonal array pattern is formed with the shrinkage strain of the film-substrate systems developing.As the interconnection of hexagonal arrays,a unit cell ridge network appears with properties such as chirality and helix.The subparagraph maze pattern formed with high compression is mainly composed of special single-cell ridge networks such as spiral single cores,chiral double cores,and combined multi-cores.This evolutionary model is highly consistent with the results of experiments,and it also predicts wrinkle morphology that has not yet been reported.These findings can serve as a novel explanation for the surface wrinkle of biological soft tissue,as well as provide references for the preparation of artificial biomaterials and programmable soft matter.
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upported by Public service development and reform pilot project of Beijing Medical Research Institute(BMR2021-3).
文摘The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)affected health,economies,and lifestyles,but little is known about its impact on children.We aimed to investigate changes in 24-hour(h)movement behaviours of pre-school children before and during COVID-19,and factors that influenced these.Children aged 3-6 years were recruited in Beijing in 2019,and their movement behaviours over 24h assessed by questionnaire,as part of the International Study of Movement Behaviors in the Early Years(SUNRISE)study.We conducted the survey again during COVID-19,and compared the children’s movement behaviours before and during COVID-19 and associated factors.Overall,196 parents completed the survey at both time points.The percentage of children meeting movement guidelines decreased during the pandemic(p<0.01).Total physical activity decreased less among children getting good quality sleep or with more adults in the household(p<0.01).Children who were not cared for primarily by their mother had a greater decrease in moderate to vigorous intensity physical activity(p=0.02),but the decrease was smaller among children whose parents used the internet to support their physical activity and/or screen time(p<0.05).Children who used electronic screen devices in the 2h before bedtime or whose parents reported body temperature in webchats had a greater increase in sedentary screen time(p<0.05).Children spending more time outdoors showed a smaller decrease in sleep(p<0.01).Overall,children’s movement behaviours changed significantly during the pandemic.
基金the National Natural Science Foundation of China(62174170)the Natural Science Foundation of Guangdong Province(2024A1515010123)+4 种基金the Shenzhen Science and Technology Program(20220807020526001)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0670000)the Shenzhen Science and Technology Program(KJZD20230923114708018,KJZD20230923114710022)the Talent Support Project of Guangdong(2021TX06C101)the Shenzhen Basic Research(JCYJ20210324115406019).
文摘Laser debonding technology has been widely used in advanced chip packaging,such as fan-out integration,2.5D/3D ICs,and MEMS devices.Typically,laser debonding of bonded pairs(R/R separation)is typically achieved by completely removing the material from the ablation region within the release material layer at high energy densities.However,this R/R separation method often results in a significant amount of release material and carbonized debris remaining on the surface of the device wafer,severely reducing product yields and cleaning efficiency for ultra-thin device wafers.Here,we proposed an interfacial separation strategy based on laser-induced hot stamping effect and thermoelastic stress wave,which enables stress-free separation of wafer bonding pairs at the interface of the release layer and the adhesive layer(R/A separation).By comprehensively analyzing the micro-morphology and material composition of the release material,we elucidated the laser debonding behavior of bonded pairs under different separation modes.Additionally,we calculated the ablation threshold of the release material in the case of wafer bonding and established the processing window for different separation methods.This work offers a fresh perspective on the development and application of laser debonding technology.The proposed R/A interface separation method is versatile,controllable,and highly reliable,and does not leave release materials and carbonized debris on device wafers,demonstrating strong industrial adaptability,which greatly facilitates the application and development of advanced packaging for ultra-thin chips.
