In order to study the preferred skin color for printing images,two CMYK images from ISO 400 and one from iStock,including five skin color images of East Asian females was selected in this study.The images were adjuste...In order to study the preferred skin color for printing images,two CMYK images from ISO 400 and one from iStock,including five skin color images of East Asian females was selected in this study.The images were adjusted with the CMYK printing ink volume variation of the single,double and triple channels in the given 280%total ink limit conditions.A larger number of color vision normal observers were organized to carry out the color preference evaluation experiment,and the selected preferred skin colors were analyzed.The distribution range of the chromaticity values for skin color images were obtained and the results indicated that there are three regions for printing skin color preferences,and the observers have a memory preference for brighter,fairer skin colors in young female and a reddish skin colors in girl,which can provide the guidance for color adjustment of printed skin color images.展开更多
A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comp...A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comparison,the model was used to investigate slab cracking tendency near precipitated phases,considering various locations,sizes and shapes of them.The results show that the jet from submerged entry nozzle creates a“double roll”flow pattern during continuous casting,resulting in more uniform temperature distributions at slab corner and wide surface center compared with narrow surface center.Consequently,precipitated phases,particularly those located on the narrow surface,readily induce stress concentration and thus increase cracking tendency.A smaller precipitated phase size can reduce the stress concentration zone,while a more spherical shape can distribute surrounding stress along its surface and lower the internal stress within it,thereby decreasing the risk of slab cracking during continuous casting.The optimal precipitated phase exhibits a spherical or ellipsoidal shape with a major axis of less than 5µm,minimizing its potential to initiate cracks.展开更多
Deeply buried mountain tunnels are often exposed to the risk of rock bursts,which always cause serious damage to the supporting structures and threaten the safety of the engineers.Due to the limited data available,a s...Deeply buried mountain tunnels are often exposed to the risk of rock bursts,which always cause serious damage to the supporting structures and threaten the safety of the engineers.Due to the limited data available,a suitable approach to predict the rockburst tendency at the preliminary stage becomes very important.In this study,an integrated methodology combining 3D initial stress inversion and rockburst tendency prediction was developed and subsequently applied to a case study of the Sangzhuling Tunnel on the Sichuan–Tibet Railway.The numerical modelling involved inverting the initial stress field using a multiple linear regression method.The tunnel excavation was simulated separately by FDM and DEM,based on a stress boundary condition from the inverted stress field.The comparative analysis demonstrates that the rockburst ratio calculated using DEM(76.70%)exhibits a slight increase compared to FDM(75.38%),and the rockburst location is consistent with the actual situation.This suggests that DEM is more suitable for simulating the stress redistribution during excavation in a jointed rock mass.The numerical simulation combined with the deviatoric stress approach effectively predicts rockburst tendency,meeting the engineering requirements.Despite its limitations,numerical simulation remains a reliable method for predicting rock bursts.展开更多
By using the Chinese stock market data from 2018 to 2024,the weak association between structural trends stocks and market index under investors’preference effect in trading cause the market is lack of liquidity and m...By using the Chinese stock market data from 2018 to 2024,the weak association between structural trends stocks and market index under investors’preference effect in trading cause the market is lack of liquidity and more likely to be dominated by structural trends,as in this market,the willingness to engage in passive trading exceeds that for active trading and investors’preference easy to reverse toward market volatility.The lack of incremental capital in the market often leads to sector-specific rallies rather than broad-based increases,which is one of the key reasons why the Chinese stock market has struggled to achieve overall growth over the long-term period.展开更多
Objective This study explored the job choice preferences of Center for Disease Prevention and Control(CDC)workers to provide CDC management information and recommendations for optimizing employee retention and motivat...Objective This study explored the job choice preferences of Center for Disease Prevention and Control(CDC)workers to provide CDC management information and recommendations for optimizing employee retention and motivation policies.Methods A discrete choice experiment was conducted in nine provinces across China.Seven key attributes were identified to analyze the job preferences of CDC workers.Mixed logit models,latent class models,and policy simulation tools were used.Results A valid sample of 5,944 cases was included in the analysis.All seven attributes significantly influenced the job choices of CDC workers.Heterogeneity analyses identified two main groups based on different levels of preference for attribute utility.Income-prioritizers were concerned with income and opportunities for career development,whereas bianzhi-prioritizers were concerned with bianzhi and welfare benefits.The policy simulation analysis revealed that income-prioritizers had a relatively higher sensitivity to multiple job preference incentives.Conclusion Income and bianzhi were the two key attributes influencing the job choices and retention preferences of CDC workers.Heterogeneity in job preferences was also identified.Based on the preference characteristics of different subgroups,policy content should be skewed to differentiate the importance of incentives.展开更多
A new wave of artificial intelligence(AI) development is sweeping the world. Considering its technology maturity and application scale, AI is in an infant stage of development. However, as the core technology and appl...A new wave of artificial intelligence(AI) development is sweeping the world. Considering its technology maturity and application scale, AI is in an infant stage of development. However, as the core technology and application driving the fourth scientific and technological revolution, AI has attracted worldwide attention for its potential transformative nature. The international community has expressed great concern over AI security, and the call for strengthening governance is growing. The international governance of AI has exhibited a strong preference for security. The underlying logic relates to AI's history,technological characteristics, and geopolitical changes. Such a security preference has determined the cognition, vision, and practical priorities of AI governance and will impact the future of AI and even the international balance of power.展开更多
Transient receptor potential(TRP)channels are a class of ion channel proteins that are closely related to thermosensation in insects.They are involved in detecting the ambient temperature and play vital roles in insec...Transient receptor potential(TRP)channels are a class of ion channel proteins that are closely related to thermosensation in insects.They are involved in detecting the ambient temperature and play vital roles in insect survival and reproduction.In this study,we identifed and cloned two variants of the TRPA subfamily gene in Myzus persicae,MperTRPA1(A)and MperTRPA1(B),and analyzed their tissue expression by real-time quantitative PCR.Subsequently,these two variants of MperTRPA1 were expressed in the Xenopus oocyte system,and their functions were investigated using the two-electrode voltage clamp technique.The role of the MperTRPA1 gene in temperature adaptation of M.persicae was further determined by RNA interference and a behavioral choice assay to evaluate responses to temperature gradients.The results showed that the MperTRPA1 gene is widely expressed in tissues of M.persicae,with MperTRPA1(A)highly expressed in the mouthparts and MperTRPA1(B)mainly expressed in the antennae.The functional characterization results showed that both variants of MperTRPA1 could be activated and were not desensitized when the temperature increased from 20 to 45℃.The current value and thermal sensitivity(coeffcient Q_(10)value)of MperTRPA1(B)were signifcantly higher than those of MperTRPA1(A).When the MperTRPA1 gene was knocked down,the behavioral preference of M.persicae for the optimal temperature was reduced and tended to be at a higher temperature,showing a shift in the temperature adaptation range compared to both the wild type and ds GFP-treated M.persicae.In summary,our results elucidated the molecular mechanism of adaptive temperature perception in M.persicae mediated by the thermal sensor MperTRPA1.展开更多
The ability of queens and males of most ant species to disperse by flight has fundamentally contributed to the group’s evolutionary and ecological success and is a determining factor to take into account for biogeogr...The ability of queens and males of most ant species to disperse by flight has fundamentally contributed to the group’s evolutionary and ecological success and is a determining factor to take into account for biogeographic studies(Wagner and Liebherr 1992;Peeters and Ito 2001;Helms 2018).展开更多
The synoptic process of a super Arctic cyclone in August 2016(AC16)is investigated based on the Weather Research and Forecasting(WRF)model,and the key factors affecting the rapid intensification(RI)of AC16 and their r...The synoptic process of a super Arctic cyclone in August 2016(AC16)is investigated based on the Weather Research and Forecasting(WRF)model,and the key factors affecting the rapid intensification(RI)of AC16 and their relative contributions are analyzed by diagnosing a new surface pressure tendency equation(SPTE).The major physical mechanisms behind the two RI stages of AC16 are revealed.The trajectory,intensity changes,and structural characteristics of AC16 are well simulated by the WRF model.A diagnosis based on the SPTE promisingly reproduces the two RI stages of AC16.The leading factor that influenced the intensity of AC16 was identified to be the air-column potential temperature tendency,while the pressure change at the upper boundary had less of an impact.Further analysis reveals that the horizontal potential temperature advection was the decisive factor in a warming of the air column.Specifically,the upper-level warm advection generated by the strong wind field of the upper-level jet played a dominant role in warming the air column,which caused the initial RI of AC16.The AC16 movement into a strong potential temperature gradient generated by tropopause polar vortices increased the upper-level warm advection,which warmed the air column and thereby induced the second RI of AC16.However,the net effect of vertical potential temperature advection and latent heating,as well as radiation processes,caused a cooling of the air column and thereby negatively contributed to the RI of AC16.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
Objective Although dietary preferences influence chronic diseases,few studies have linked dietary preferences to mortality risk,particularly in large cohorts.To investigate the relationship between dietary preferences...Objective Although dietary preferences influence chronic diseases,few studies have linked dietary preferences to mortality risk,particularly in large cohorts.To investigate the relationship between dietary preferences and mortality risk(all-cause,cancer,and cardiovascular disease[CVD])in a large adult cohort.Methods A cohort of 1,160,312 adults(mean age 62.48±9.55)from the Shenzhen Healthcare Big Data Cohort(SHBDC)was analyzed.Hazard ratios(HRs)for mortality were estimated using the Cox proportional hazards model.Results The study identified 12,308 all-cause deaths,of which 3,865(31.4%)were cancer-related and 3,576(29.1%)were attributed to CVD.Compared with a mixed diet of meat and vegetables,a mainly meat-based diet(hazard ratio[HR]=1.13;95%confidence interval[CI]:1.02,1.27)associated with a higher risk of all-cause mortality,while mainly vegetarian(HR=0.87;95%CI:0.78,0.97)was linked to a reduced risk.Furthermore,there was a stronger correlation between mortality risk and dietary preference in the>65 age range.Conclusion A meat-based diet was associated with an increased risk of all-cause mortality,whereas a mainly vegetarian diet was linked to a reduced risk.展开更多
Objectives:Positive family functioning(FF)is critical for adolescent development,yet only a few studies have examined this developmental trajectory pathway.This study aimed to identify different types of FF developmen...Objectives:Positive family functioning(FF)is critical for adolescent development,yet only a few studies have examined this developmental trajectory pathway.This study aimed to identify different types of FF development trajectories during junior high school students,investigate their influence on social avoidance(SA),and further examine the mediating role of preference for solitude(PS)between them.Methods:A three-wave longitudinal study was used with six-month intervals.Questionnaire data were collected from 436 junior high school students in Jiangxi Province,China.Participants ranged in age from 11 to 14 years old(Mean=12.89 years,SD=1.08;50.2%male).Results:Four heterogeneous types of FF trajectories were identified:(1)a high and increasing group(14.7%);(2)a consistently high group(36.24%);(3)a consistently moderate group(45.86%);and(4)a rapid growth group(3.2%).The developmental trajectories of FF among junior high students significantly varied in their levels of SA(F(3,432)=32.03,p<0.001).Compared to the high and increasing groups,the consistently high,consistently medium,and rapid growth groups exhibited higher levels of SA.PS mediated the association between the developmental trajectory of FF and SA.Conclusion:There was a close relationship between the developmental trajectory of FF and SA.Interventions focusing on family system optimization and solitary preference management could effectively mitigate SA behaviors.These findings are important for promoting healthy socialization in adolescents.展开更多
Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they r...Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.Here,we constructed an 11-year experiment involving fungicide application(with or without)nested within four levels of experimental nitrogen(N)addition treatments in an alpine pasture,and the RAF communities,root traits,tissue nutrients,and shoot biomass of two dominant forage species(Carex capillifolia and Elymus nutans)were analyzed.The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.Fungicide,but not N application,dramatically reduced the RAF richness of all functional guilds in both plant species,and fungicide also simplified the co-occurrence network of the RAF for C.capillifolia.The RAF community correlated strongly with root traits,whereas their relationships became weakened or even vanished at the level of the individual plant species.The importance of RAF to plant nutrients and productivity varied between plant species,with significant contributions in C.capillifolia but not in E.nutans.This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures,and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.展开更多
Objective:To investigate the preference characteristics and relative importance of each core factor in the teaching program for undergraduate nursing students during clinical practice,and to provide empirical support ...Objective:To investigate the preference characteristics and relative importance of each core factor in the teaching program for undergraduate nursing students during clinical practice,and to provide empirical support for the creation of a student-centered,formalized clinical teaching system that meets the actual needs of nursing students.Methods:The quantitative research method of discrete choice experiment was adopted,and the questionnaire was designed based on the random utility theory.Through a systematic literature review,semi-structured interviews,and two rounds of Delphi expert consultations,six core attributes of the instructor,namely educational qualifications,teaching methods,frequency of individualized guidance,operational practice opportunities,feedback timeliness,and instructor title,and their corresponding levels were determined.The study period was from January 2024 to January 2025,and 158 undergraduate nursing students who chose to intern at Deyang People’s Hospital were selected as the research subjects.A survey tool with 12 choice sets was created using Ngene software,and then statistical analysis was performed on the obtained data using the conditional Logit model to measure the impact of each attribute on the choice behavior of nursing students.Results:The results showed that the conditional Logit model fitted well(likelihood ratio chi-square=85.32,p<0.001).The analysis results indicated that the most important teaching attributes for undergraduate nursing students were,in order:the academic qualifications of the teaching instructor(master vs.Junior college,β=0.42,p<0.01),individualized guidance frequency(daily vs.Weekly,β=0.38,p<0.01),operational practice opportunities(more vs.less,β=0.31,p<0.05),and the timeliness of feedback(timely versus delayed,β=0.29,p<0.05).The influence of the title of the instructor was not statistically significant(p>0.05).Conclusion:Undergraduate nursing students show a clear and systematic preference structure for clinical teaching,with a high expectation of frequent personalized guidance from highly educated teachers,as well as sufficient operational opportunities and timely teaching feedback.展开更多
To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with...To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with varying gangue thicknesses and positions.The response patterns of compressive strength,elastic modulus,pre-peak accumulated energy,elastic energy index,and impact energy index were systematically analyzed.Furthermore,a new index for evaluating the impact tendency of gangue-containing coal was proposed,and its effectiveness was verified.The findings are as follows:(1)As the gangue thickness increases,both the compressive strength and the pre-peak energy of the combined structure decrease,whereas the elastic modulus increases accordingly.When the gangue is located in the lower middle position,the combined structure exhibits the lowest compressive strength and elastic modulus but the highest pre peak energy.(2)As the gangue shifts toward the middle position of the combined structure,the failure mode gradually transitions from comple te“crushing”failure to an incomplete“point-type”failure.As gangue thickness further increases,the failure region evolves from overall failure to localized failure,with the degree of failure shifting from complete to incomplete.The K_(crc)value corresponding to“crushing”complete failure is higher and has a stronger impact tendency compared to“point-type”incomplete failure.(3)The proposed comprehensive impact instability evaluation index K_(crc)for the gangue-coal combined structure has shown a significant positive correlation with compressive strength(R_(c))and impact energy index(K_(E)),further verifyi ng its rationality in comprehensively assessing the impact tendency of gangue-containing coal bodies.Applying this index to the evaluation of gangue-containing coal seams provides a more accurate reflection of their impact tendency compared with the residual energy index,which has a wide range of potential applications and practical significance.展开更多
BACKGROUND Intellectual disability(ID),affecting 1%-3%of children globally,presents significant challenges for parents that often translate into occupational stress.While studies document elevated parenting stress lev...BACKGROUND Intellectual disability(ID),affecting 1%-3%of children globally,presents significant challenges for parents that often translate into occupational stress.While studies document elevated parenting stress levels(33.57 vs 26.46 in controls),job-related impacts remain poorly understood.This study employs propensity score matching(PSM)to rigorously analyze work stress determinants among parents of preschool-aged children with ID,controlling for socioeconomic and behavioral confounders.The research bridges a critical gap by examining how workplace demands intersect with special caregiving responsibilities,aiming to identify modifiable risk factors for targeted interventions.Findings will inform evidence-based workplace accommodations and support policies,offering novel insights into the occupational consequences of parenting a child with ID through advanced causal inference methods.This work holds important implications for hazard ratio(HR)policies and social support systems serving this vulnerable population.AIM To explore the factors affecting the job stress of parents of preschool children with mental retardation(MR),based on the PSM.METHODS One hundred and twenty-five children aged 3-6 years who were treated in our hospital from December 2022 to December 2024 were included in the questionnaire survey.Five cases were excluded due to incomplete data,and 120 cases completed the study.The questionnaire was filled out by the parents of the children,and 100 parents of normal children were selected to be included in the control group.After the baseline difference was balanced by PSM 1:1 matching,the general information,scores of parental stress in each dimension and parental stress level of the two groups were compared and analyzed.Single factor analysis was carried out on the factors affecting the parental stress of group;Pearson was used to analyze the correlation between the factors affecting parental stress in MR group.Logistic regression was used to analyze the factors affecting the job stress of parents in MR group.RESULTS After matching,there were 97 cases in both groups.The differences of parents'working status and family location in MR group were statistically significant,P<0.05.Parents in MR group were significantly higher than those in control group in every dimension and total score,of which 75.22%were at a high level,P<0.05.Univariate analysis shows that the older the parents are,the more unstable their work status is,the lower their education level is,the less their family income is,their location is in the countryside and the children have a genetic history,the higher their parental stress score is.Pearson correlation analysis showed that the total score of parental stress was related to supporting friends(r=-0.354),seeking social support,maintaining self-esteem and psychological stability(r=-0.146),coping style frequency(r=-0.476)and role size(r=-0.063).P<0.05.Using the binary Logistic regression model,it was found that whether the child had a genetic history(HR=1.667)was a risk factor affecting the parents'job stress of MR children,and friends'support(HR=0.539),seeking social support(HR=0.478),maintaining self-esteem and psychological stability(HR=0.625),and the frequency and role of coping styles(HR=0.794)were all its protective factors,P<0.05.CONCLUSION Parents'parental stress of most preschool children with MR is at a high level,in which children's genetic history is its risk factor,and friends'support,seeking social support,maintaining self-esteem and psychological stability,as well as the frequency and role of coping styles are its protective factors,which provides new intervention programs and measures to alleviate parents'parental stress of MR children.展开更多
The real-time path optimization for heterogeneous vehicle fleets in large-scale road networks presents significant challenges due to conflicting traffic demands and imbalanced resource allocation.While existing vehicl...The real-time path optimization for heterogeneous vehicle fleets in large-scale road networks presents significant challenges due to conflicting traffic demands and imbalanced resource allocation.While existing vehicleto-infrastructure coordination frameworks partially address congestion mitigation,they often neglect priority-aware optimization and exhibit algorithmic bias toward dominant vehicle classes—critical limitations in mixed-priority scenarios involving emergency vehicles.To bridge this gap,this study proposes a preference game-theoretic coordination framework with adaptive strategy transfer protocol,explicitly balancing system-wide efficiency(measured by network throughput)with priority vehicle rights protection(quantified via time-sensitive utility functions).The approach innovatively combines(1)a multi-vehicle dynamic routing model with quantifiable preference weights,and(2)a distributed Nash equilibrium solver updated using replicator sub-dynamic models.The framework was evaluated on an urban road network containing 25 intersections with mixed priority ratios(10%–30%of vehicles with priority access demand),and the framework showed consistent benefits on four benchmarks(Social routing algorithm,Shortest path algorithm,The comprehensive path optimisation model,The emergency vehicle timing collaborative evolution path optimization method)showed consistent benefits.Results showthat across different traffic demand configurations,the proposed method reduces the average vehicle traveling time by at least 365 s,increases the road network throughput by 48.61%,and effectively balances the road loads.This approach successfully meets the diverse traffic demands of various vehicle types while optimizing road resource allocations.The proposed coordination paradigm advances theoretical foundations for fairness-aware traffic optimization while offering implementable strategies for next-generation cooperative vehicle-road systems,particularly in smart city deployments requiring mixed-priority mobility guarantees.展开更多
Demand-responsive transportation has been introduced in many cities around the world.However,whether it is applicable in the railway is still questionable,an exploration of passenger choice behavior between demandresp...Demand-responsive transportation has been introduced in many cities around the world.However,whether it is applicable in the railway is still questionable,an exploration of passenger choice behavior between demandresponsive trains and pre-scheduled trains is pivotal in addressing this issue.To delve into passengers’choice preferences when facing demand-responsive trains and to dissect the feasibility of implementing demandresponsive service in high-speed railways,the stated preference survey method is employed to investigate travel intention of passengers.Based on the survey data obtained in China,the heterogeneity of passengers is analyzed from three aspects:personal socio-economic characteristics,travel characteristics,and travel mode choice.Considering the situation that demand-responsive train cannot operate,the risk attributes are considered.To bolster the appeal of demand-responsive trains,personalized service product attributes are added.Mixed Logit mode,which takes into account the heterogeneous travel choice behavior of passengers,is developed,and Maximum Likelihood Estimation and the Monte Carlo method are used to calibrate model parameters.The willingness to pay in terms of different factors of passengers is determined.The results indicate that early arrival deviation time,late arrival deviation time,demand response time,and success rate of ticket purchase remarkable influence passengers’decision regarding demand-responsive train,with only the success rate of ticket purchase positively impacting train choice.Moreover,the significant difference in train ticket price is observed solely in the self-funded long distance scenario,while demand-responsive trains are found to be particularly appealing in self-funded short distance scenario.Through the Willingness To Pay(WTP)analysis,it is discovered that by shortening demand response time,enhancing the success rate of ticket purchase,and minimizing the deviation times of early arrival and late arrival of trains,the attractiveness of the demand-responsive train to passengers under three travel scenarios can be augmented.This study provides profound insights into the possibility of railway enterprises operating demand-responsive trains.展开更多
During direct chilling(DC)casting of ZK61 alloys,the primary and secondary cooling causes strong thermal gradients,which leads to the uneven crystallization rate and thermal contraction in different positions of the i...During direct chilling(DC)casting of ZK61 alloys,the primary and secondary cooling causes strong thermal gradients,which leads to the uneven crystallization rate and thermal contraction in different positions of the ingot.The consequences manifested appearance of heterogeneous grains,huge casting stresses,and even hot cracking flaws.In this paper,chemical and physical methods were integrated to produce large-scale magnesium(Mg)alloy ingots.A φ525 mm ZK61-RE alloy ingot that was refined,homogeneous,and free from hot cracking was obtained via the DC process coupled with a differential low frequency pulsed magnetic field(DLPM).The effects of rare earth(RE)and DLPM on the hot cracking tendency were investigated,and the mechanism of hot cracking formation and modification in largescale ingots was revealed.The findings indicate that the addition of moderate amounts of RE lessens the tendency of hot cracking in large-scale ZK61 alloy ingots.This is mainly attributed to the addition of RE increases the content of the second phase,thus enhancing the ability of the eutectic liquid phase to feed the cracking.With the introduction of DLPM,the grain sizes are significantly refined and homogenized,and there is no obvious hot cracking observed in the ingot.This is because the coupling of the DLPM provides a more homogeneous temperature field,leading to the synchronization of the solidification process,and the consequent reduction of the casting stress,thus reducing the driving force for the formation of hot cracking.In addition,the casting conditions are modified to enhance the ability of solidification feeding and the resistance to hot cracking.This work provides theoretical and practical references for the preparation of large-scale high-quality Mg alloy ingots.展开更多
To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata,this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes....To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata,this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes.The tests involved loading the samples to 60%,70%,and 80%of their uniaxial compressive strength,followed by unloading and reloading until failure.Key parameters such as the elastic energy index and linear elasticity criteria were derived from these tests.Additionally,rock fragments were collected to calculate their initial ejection kinetic energy,serving as a measure of rockburst tendency.The classification of rockburst tendency was conducted using grading methods based on burst energy index(WET),pre-peak stored elastic energy(PES)and experimental observations.Multi-class classification and regression analyses were applied to machine learning models using experimental data to predict rockburst tendency levels.A comparative analysis of models from two libraries revealed that the Random Forest model achieved the highest accuracy in classification,while the Ada Boost Regressor model excelled in regression predictions.This study highlights that on a laboratory scale,integrating ejection kinetic energy with the unloading ratio,failure load,W_(ET)and PES through machine learning offers a highly accurate and reliable approach for determining rockburst tendency levels.展开更多
文摘In order to study the preferred skin color for printing images,two CMYK images from ISO 400 and one from iStock,including five skin color images of East Asian females was selected in this study.The images were adjusted with the CMYK printing ink volume variation of the single,double and triple channels in the given 280%total ink limit conditions.A larger number of color vision normal observers were organized to carry out the color preference evaluation experiment,and the selected preferred skin colors were analyzed.The distribution range of the chromaticity values for skin color images were obtained and the results indicated that there are three regions for printing skin color preferences,and the observers have a memory preference for brighter,fairer skin colors in young female and a reddish skin colors in girl,which can provide the guidance for color adjustment of printed skin color images.
基金supported by National Natural Science Foundation of China(Nos.52325406 and 52374330)Fundamental Research Funds for the Central Universities(No.N2225046).
文摘A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comparison,the model was used to investigate slab cracking tendency near precipitated phases,considering various locations,sizes and shapes of them.The results show that the jet from submerged entry nozzle creates a“double roll”flow pattern during continuous casting,resulting in more uniform temperature distributions at slab corner and wide surface center compared with narrow surface center.Consequently,precipitated phases,particularly those located on the narrow surface,readily induce stress concentration and thus increase cracking tendency.A smaller precipitated phase size can reduce the stress concentration zone,while a more spherical shape can distribute surrounding stress along its surface and lower the internal stress within it,thereby decreasing the risk of slab cracking during continuous casting.The optimal precipitated phase exhibits a spherical or ellipsoidal shape with a major axis of less than 5µm,minimizing its potential to initiate cracks.
基金financially supported by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology)(Grant No.SKLGP2020Z007)。
文摘Deeply buried mountain tunnels are often exposed to the risk of rock bursts,which always cause serious damage to the supporting structures and threaten the safety of the engineers.Due to the limited data available,a suitable approach to predict the rockburst tendency at the preliminary stage becomes very important.In this study,an integrated methodology combining 3D initial stress inversion and rockburst tendency prediction was developed and subsequently applied to a case study of the Sangzhuling Tunnel on the Sichuan–Tibet Railway.The numerical modelling involved inverting the initial stress field using a multiple linear regression method.The tunnel excavation was simulated separately by FDM and DEM,based on a stress boundary condition from the inverted stress field.The comparative analysis demonstrates that the rockburst ratio calculated using DEM(76.70%)exhibits a slight increase compared to FDM(75.38%),and the rockburst location is consistent with the actual situation.This suggests that DEM is more suitable for simulating the stress redistribution during excavation in a jointed rock mass.The numerical simulation combined with the deviatoric stress approach effectively predicts rockburst tendency,meeting the engineering requirements.Despite its limitations,numerical simulation remains a reliable method for predicting rock bursts.
文摘By using the Chinese stock market data from 2018 to 2024,the weak association between structural trends stocks and market index under investors’preference effect in trading cause the market is lack of liquidity and more likely to be dominated by structural trends,as in this market,the willingness to engage in passive trading exceeds that for active trading and investors’preference easy to reverse toward market volatility.The lack of incremental capital in the market often leads to sector-specific rallies rather than broad-based increases,which is one of the key reasons why the Chinese stock market has struggled to achieve overall growth over the long-term period.
基金supported by the Major Program of the National Social Science Foundation of China(no.2022YFC3600801)the Operation of Public Health Emergency Response Mechanisms of the Chinese Center for Disease Control and Prevention(no.102393220020010000017)。
文摘Objective This study explored the job choice preferences of Center for Disease Prevention and Control(CDC)workers to provide CDC management information and recommendations for optimizing employee retention and motivation policies.Methods A discrete choice experiment was conducted in nine provinces across China.Seven key attributes were identified to analyze the job preferences of CDC workers.Mixed logit models,latent class models,and policy simulation tools were used.Results A valid sample of 5,944 cases was included in the analysis.All seven attributes significantly influenced the job choices of CDC workers.Heterogeneity analyses identified two main groups based on different levels of preference for attribute utility.Income-prioritizers were concerned with income and opportunities for career development,whereas bianzhi-prioritizers were concerned with bianzhi and welfare benefits.The policy simulation analysis revealed that income-prioritizers had a relatively higher sensitivity to multiple job preference incentives.Conclusion Income and bianzhi were the two key attributes influencing the job choices and retention preferences of CDC workers.Heterogeneity in job preferences was also identified.Based on the preference characteristics of different subgroups,policy content should be skewed to differentiate the importance of incentives.
文摘A new wave of artificial intelligence(AI) development is sweeping the world. Considering its technology maturity and application scale, AI is in an infant stage of development. However, as the core technology and application driving the fourth scientific and technological revolution, AI has attracted worldwide attention for its potential transformative nature. The international community has expressed great concern over AI security, and the call for strengthening governance is growing. The international governance of AI has exhibited a strong preference for security. The underlying logic relates to AI's history,technological characteristics, and geopolitical changes. Such a security preference has determined the cognition, vision, and practical priorities of AI governance and will impact the future of AI and even the international balance of power.
基金funded by the National Natural Science Foundation of China(32472553 and 31872039)the Major Special Projects for Green Pest Control,China(110202201017(LS-01))+1 种基金the Shenzhen Science and Technology Program,China(KQTD20180411143628272)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences。
文摘Transient receptor potential(TRP)channels are a class of ion channel proteins that are closely related to thermosensation in insects.They are involved in detecting the ambient temperature and play vital roles in insect survival and reproduction.In this study,we identifed and cloned two variants of the TRPA subfamily gene in Myzus persicae,MperTRPA1(A)and MperTRPA1(B),and analyzed their tissue expression by real-time quantitative PCR.Subsequently,these two variants of MperTRPA1 were expressed in the Xenopus oocyte system,and their functions were investigated using the two-electrode voltage clamp technique.The role of the MperTRPA1 gene in temperature adaptation of M.persicae was further determined by RNA interference and a behavioral choice assay to evaluate responses to temperature gradients.The results showed that the MperTRPA1 gene is widely expressed in tissues of M.persicae,with MperTRPA1(A)highly expressed in the mouthparts and MperTRPA1(B)mainly expressed in the antennae.The functional characterization results showed that both variants of MperTRPA1 could be activated and were not desensitized when the temperature increased from 20 to 45℃.The current value and thermal sensitivity(coeffcient Q_(10)value)of MperTRPA1(B)were signifcantly higher than those of MperTRPA1(A).When the MperTRPA1 gene was knocked down,the behavioral preference of M.persicae for the optimal temperature was reduced and tended to be at a higher temperature,showing a shift in the temperature adaptation range compared to both the wild type and ds GFP-treated M.persicae.In summary,our results elucidated the molecular mechanism of adaptive temperature perception in M.persicae mediated by the thermal sensor MperTRPA1.
基金funded by the“Departments of Excellence”program of the Italian Ministry for University and Research(MIUR,2018-2022 and MUR,2023-2027).
文摘The ability of queens and males of most ant species to disperse by flight has fundamentally contributed to the group’s evolutionary and ecological success and is a determining factor to take into account for biogeographic studies(Wagner and Liebherr 1992;Peeters and Ito 2001;Helms 2018).
基金sponsored by the funding of the National Natural Science Foundation of China(Grant Nos.42075011,42192552,42005025,and 42075035).
文摘The synoptic process of a super Arctic cyclone in August 2016(AC16)is investigated based on the Weather Research and Forecasting(WRF)model,and the key factors affecting the rapid intensification(RI)of AC16 and their relative contributions are analyzed by diagnosing a new surface pressure tendency equation(SPTE).The major physical mechanisms behind the two RI stages of AC16 are revealed.The trajectory,intensity changes,and structural characteristics of AC16 are well simulated by the WRF model.A diagnosis based on the SPTE promisingly reproduces the two RI stages of AC16.The leading factor that influenced the intensity of AC16 was identified to be the air-column potential temperature tendency,while the pressure change at the upper boundary had less of an impact.Further analysis reveals that the horizontal potential temperature advection was the decisive factor in a warming of the air column.Specifically,the upper-level warm advection generated by the strong wind field of the upper-level jet played a dominant role in warming the air column,which caused the initial RI of AC16.The AC16 movement into a strong potential temperature gradient generated by tropopause polar vortices increased the upper-level warm advection,which warmed the air column and thereby induced the second RI of AC16.However,the net effect of vertical potential temperature advection and latent heating,as well as radiation processes,caused a cooling of the air column and thereby negatively contributed to the RI of AC16.
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.
基金supported by the National Natural Science Foundation of China(No.82425052).
文摘Objective Although dietary preferences influence chronic diseases,few studies have linked dietary preferences to mortality risk,particularly in large cohorts.To investigate the relationship between dietary preferences and mortality risk(all-cause,cancer,and cardiovascular disease[CVD])in a large adult cohort.Methods A cohort of 1,160,312 adults(mean age 62.48±9.55)from the Shenzhen Healthcare Big Data Cohort(SHBDC)was analyzed.Hazard ratios(HRs)for mortality were estimated using the Cox proportional hazards model.Results The study identified 12,308 all-cause deaths,of which 3,865(31.4%)were cancer-related and 3,576(29.1%)were attributed to CVD.Compared with a mixed diet of meat and vegetables,a mainly meat-based diet(hazard ratio[HR]=1.13;95%confidence interval[CI]:1.02,1.27)associated with a higher risk of all-cause mortality,while mainly vegetarian(HR=0.87;95%CI:0.78,0.97)was linked to a reduced risk.Furthermore,there was a stronger correlation between mortality risk and dietary preference in the>65 age range.Conclusion A meat-based diet was associated with an increased risk of all-cause mortality,whereas a mainly vegetarian diet was linked to a reduced risk.
基金supported by the National Natural Science Foundation of China(72164018)National Social Science Fund Project(BFA200065)Jiangxi Social Science Foundation Project(21JY13).
文摘Objectives:Positive family functioning(FF)is critical for adolescent development,yet only a few studies have examined this developmental trajectory pathway.This study aimed to identify different types of FF development trajectories during junior high school students,investigate their influence on social avoidance(SA),and further examine the mediating role of preference for solitude(PS)between them.Methods:A three-wave longitudinal study was used with six-month intervals.Questionnaire data were collected from 436 junior high school students in Jiangxi Province,China.Participants ranged in age from 11 to 14 years old(Mean=12.89 years,SD=1.08;50.2%male).Results:Four heterogeneous types of FF trajectories were identified:(1)a high and increasing group(14.7%);(2)a consistently high group(36.24%);(3)a consistently moderate group(45.86%);and(4)a rapid growth group(3.2%).The developmental trajectories of FF among junior high students significantly varied in their levels of SA(F(3,432)=32.03,p<0.001).Compared to the high and increasing groups,the consistently high,consistently medium,and rapid growth groups exhibited higher levels of SA.PS mediated the association between the developmental trajectory of FF and SA.Conclusion:There was a close relationship between the developmental trajectory of FF and SA.Interventions focusing on family system optimization and solitary preference management could effectively mitigate SA behaviors.These findings are important for promoting healthy socialization in adolescents.
基金supported by the National Key Research and Development Program of China(2023YFF0805602)the National Natural Science Foundation of China(U21A20186,32171579,32371592 and 32471674)the Natural Science Foundation of Gansu Province,China(23JRRA1029 and 23JRRA1034)。
文摘Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.Here,we constructed an 11-year experiment involving fungicide application(with or without)nested within four levels of experimental nitrogen(N)addition treatments in an alpine pasture,and the RAF communities,root traits,tissue nutrients,and shoot biomass of two dominant forage species(Carex capillifolia and Elymus nutans)were analyzed.The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.Fungicide,but not N application,dramatically reduced the RAF richness of all functional guilds in both plant species,and fungicide also simplified the co-occurrence network of the RAF for C.capillifolia.The RAF community correlated strongly with root traits,whereas their relationships became weakened or even vanished at the level of the individual plant species.The importance of RAF to plant nutrients and productivity varied between plant species,with significant contributions in C.capillifolia but not in E.nutans.This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures,and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.
基金Teaching Reform Research Project at Southwest Medical University(Project No.:JG2023jdyb034)Humanities and Social Sciences Research Project at Sichuan Vocational College of Nursing(Project No.:2022RWSY45)。
文摘Objective:To investigate the preference characteristics and relative importance of each core factor in the teaching program for undergraduate nursing students during clinical practice,and to provide empirical support for the creation of a student-centered,formalized clinical teaching system that meets the actual needs of nursing students.Methods:The quantitative research method of discrete choice experiment was adopted,and the questionnaire was designed based on the random utility theory.Through a systematic literature review,semi-structured interviews,and two rounds of Delphi expert consultations,six core attributes of the instructor,namely educational qualifications,teaching methods,frequency of individualized guidance,operational practice opportunities,feedback timeliness,and instructor title,and their corresponding levels were determined.The study period was from January 2024 to January 2025,and 158 undergraduate nursing students who chose to intern at Deyang People’s Hospital were selected as the research subjects.A survey tool with 12 choice sets was created using Ngene software,and then statistical analysis was performed on the obtained data using the conditional Logit model to measure the impact of each attribute on the choice behavior of nursing students.Results:The results showed that the conditional Logit model fitted well(likelihood ratio chi-square=85.32,p<0.001).The analysis results indicated that the most important teaching attributes for undergraduate nursing students were,in order:the academic qualifications of the teaching instructor(master vs.Junior college,β=0.42,p<0.01),individualized guidance frequency(daily vs.Weekly,β=0.38,p<0.01),operational practice opportunities(more vs.less,β=0.31,p<0.05),and the timeliness of feedback(timely versus delayed,β=0.29,p<0.05).The influence of the title of the instructor was not statistically significant(p>0.05).Conclusion:Undergraduate nursing students show a clear and systematic preference structure for clinical teaching,with a high expectation of frequent personalized guidance from highly educated teachers,as well as sufficient operational opportunities and timely teaching feedback.
基金Project(52274130)supported by the National Natural Science Foundation of ChinaProject(ZR2024ZD22)supported by the Major Basic Research Project of the Shandong Provincial Natural Science Foundation,China+1 种基金Project(2023375)supported by the Guizhou University Research and Innovation Team,ChinaProject(LH[2024]-026)supported by the Guizhou Science and Technology Plan Project,China。
文摘To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with varying gangue thicknesses and positions.The response patterns of compressive strength,elastic modulus,pre-peak accumulated energy,elastic energy index,and impact energy index were systematically analyzed.Furthermore,a new index for evaluating the impact tendency of gangue-containing coal was proposed,and its effectiveness was verified.The findings are as follows:(1)As the gangue thickness increases,both the compressive strength and the pre-peak energy of the combined structure decrease,whereas the elastic modulus increases accordingly.When the gangue is located in the lower middle position,the combined structure exhibits the lowest compressive strength and elastic modulus but the highest pre peak energy.(2)As the gangue shifts toward the middle position of the combined structure,the failure mode gradually transitions from comple te“crushing”failure to an incomplete“point-type”failure.As gangue thickness further increases,the failure region evolves from overall failure to localized failure,with the degree of failure shifting from complete to incomplete.The K_(crc)value corresponding to“crushing”complete failure is higher and has a stronger impact tendency compared to“point-type”incomplete failure.(3)The proposed comprehensive impact instability evaluation index K_(crc)for the gangue-coal combined structure has shown a significant positive correlation with compressive strength(R_(c))and impact energy index(K_(E)),further verifyi ng its rationality in comprehensively assessing the impact tendency of gangue-containing coal bodies.Applying this index to the evaluation of gangue-containing coal seams provides a more accurate reflection of their impact tendency compared with the residual energy index,which has a wide range of potential applications and practical significance.
基金Supported by the Self-Funded Plan for Scientific and Technological Research and Development of Shijiazhuang City in 2022,No.221460383.
文摘BACKGROUND Intellectual disability(ID),affecting 1%-3%of children globally,presents significant challenges for parents that often translate into occupational stress.While studies document elevated parenting stress levels(33.57 vs 26.46 in controls),job-related impacts remain poorly understood.This study employs propensity score matching(PSM)to rigorously analyze work stress determinants among parents of preschool-aged children with ID,controlling for socioeconomic and behavioral confounders.The research bridges a critical gap by examining how workplace demands intersect with special caregiving responsibilities,aiming to identify modifiable risk factors for targeted interventions.Findings will inform evidence-based workplace accommodations and support policies,offering novel insights into the occupational consequences of parenting a child with ID through advanced causal inference methods.This work holds important implications for hazard ratio(HR)policies and social support systems serving this vulnerable population.AIM To explore the factors affecting the job stress of parents of preschool children with mental retardation(MR),based on the PSM.METHODS One hundred and twenty-five children aged 3-6 years who were treated in our hospital from December 2022 to December 2024 were included in the questionnaire survey.Five cases were excluded due to incomplete data,and 120 cases completed the study.The questionnaire was filled out by the parents of the children,and 100 parents of normal children were selected to be included in the control group.After the baseline difference was balanced by PSM 1:1 matching,the general information,scores of parental stress in each dimension and parental stress level of the two groups were compared and analyzed.Single factor analysis was carried out on the factors affecting the parental stress of group;Pearson was used to analyze the correlation between the factors affecting parental stress in MR group.Logistic regression was used to analyze the factors affecting the job stress of parents in MR group.RESULTS After matching,there were 97 cases in both groups.The differences of parents'working status and family location in MR group were statistically significant,P<0.05.Parents in MR group were significantly higher than those in control group in every dimension and total score,of which 75.22%were at a high level,P<0.05.Univariate analysis shows that the older the parents are,the more unstable their work status is,the lower their education level is,the less their family income is,their location is in the countryside and the children have a genetic history,the higher their parental stress score is.Pearson correlation analysis showed that the total score of parental stress was related to supporting friends(r=-0.354),seeking social support,maintaining self-esteem and psychological stability(r=-0.146),coping style frequency(r=-0.476)and role size(r=-0.063).P<0.05.Using the binary Logistic regression model,it was found that whether the child had a genetic history(HR=1.667)was a risk factor affecting the parents'job stress of MR children,and friends'support(HR=0.539),seeking social support(HR=0.478),maintaining self-esteem and psychological stability(HR=0.625),and the frequency and role of coping styles(HR=0.794)were all its protective factors,P<0.05.CONCLUSION Parents'parental stress of most preschool children with MR is at a high level,in which children's genetic history is its risk factor,and friends'support,seeking social support,maintaining self-esteem and psychological stability,as well as the frequency and role of coping styles are its protective factors,which provides new intervention programs and measures to alleviate parents'parental stress of MR children.
基金funded by the National Key Research and Development Program Project 2022YFB4300404.
文摘The real-time path optimization for heterogeneous vehicle fleets in large-scale road networks presents significant challenges due to conflicting traffic demands and imbalanced resource allocation.While existing vehicleto-infrastructure coordination frameworks partially address congestion mitigation,they often neglect priority-aware optimization and exhibit algorithmic bias toward dominant vehicle classes—critical limitations in mixed-priority scenarios involving emergency vehicles.To bridge this gap,this study proposes a preference game-theoretic coordination framework with adaptive strategy transfer protocol,explicitly balancing system-wide efficiency(measured by network throughput)with priority vehicle rights protection(quantified via time-sensitive utility functions).The approach innovatively combines(1)a multi-vehicle dynamic routing model with quantifiable preference weights,and(2)a distributed Nash equilibrium solver updated using replicator sub-dynamic models.The framework was evaluated on an urban road network containing 25 intersections with mixed priority ratios(10%–30%of vehicles with priority access demand),and the framework showed consistent benefits on four benchmarks(Social routing algorithm,Shortest path algorithm,The comprehensive path optimisation model,The emergency vehicle timing collaborative evolution path optimization method)showed consistent benefits.Results showthat across different traffic demand configurations,the proposed method reduces the average vehicle traveling time by at least 365 s,increases the road network throughput by 48.61%,and effectively balances the road loads.This approach successfully meets the diverse traffic demands of various vehicle types while optimizing road resource allocations.The proposed coordination paradigm advances theoretical foundations for fairness-aware traffic optimization while offering implementable strategies for next-generation cooperative vehicle-road systems,particularly in smart city deployments requiring mixed-priority mobility guarantees.
基金supported by the National Natural Science Foundation of China(No.72471023,71971019)the Fundamental Research Funds for the Central Universities(No.2024QYBS025).
文摘Demand-responsive transportation has been introduced in many cities around the world.However,whether it is applicable in the railway is still questionable,an exploration of passenger choice behavior between demandresponsive trains and pre-scheduled trains is pivotal in addressing this issue.To delve into passengers’choice preferences when facing demand-responsive trains and to dissect the feasibility of implementing demandresponsive service in high-speed railways,the stated preference survey method is employed to investigate travel intention of passengers.Based on the survey data obtained in China,the heterogeneity of passengers is analyzed from three aspects:personal socio-economic characteristics,travel characteristics,and travel mode choice.Considering the situation that demand-responsive train cannot operate,the risk attributes are considered.To bolster the appeal of demand-responsive trains,personalized service product attributes are added.Mixed Logit mode,which takes into account the heterogeneous travel choice behavior of passengers,is developed,and Maximum Likelihood Estimation and the Monte Carlo method are used to calibrate model parameters.The willingness to pay in terms of different factors of passengers is determined.The results indicate that early arrival deviation time,late arrival deviation time,demand response time,and success rate of ticket purchase remarkable influence passengers’decision regarding demand-responsive train,with only the success rate of ticket purchase positively impacting train choice.Moreover,the significant difference in train ticket price is observed solely in the self-funded long distance scenario,while demand-responsive trains are found to be particularly appealing in self-funded short distance scenario.Through the Willingness To Pay(WTP)analysis,it is discovered that by shortening demand response time,enhancing the success rate of ticket purchase,and minimizing the deviation times of early arrival and late arrival of trains,the attractiveness of the demand-responsive train to passengers under three travel scenarios can be augmented.This study provides profound insights into the possibility of railway enterprises operating demand-responsive trains.
基金Project supported by the Jiangxi Province Key Laboratory of Light Alloy(2024SSY05031)the National Natural Science Foundation of China(52061028)+1 种基金the National Key Research and Development Program of China(2021YFB3501001)the Major Research and Development Projects of Jiangxi Province(20223BBE51021,20213AAE02014)。
文摘During direct chilling(DC)casting of ZK61 alloys,the primary and secondary cooling causes strong thermal gradients,which leads to the uneven crystallization rate and thermal contraction in different positions of the ingot.The consequences manifested appearance of heterogeneous grains,huge casting stresses,and even hot cracking flaws.In this paper,chemical and physical methods were integrated to produce large-scale magnesium(Mg)alloy ingots.A φ525 mm ZK61-RE alloy ingot that was refined,homogeneous,and free from hot cracking was obtained via the DC process coupled with a differential low frequency pulsed magnetic field(DLPM).The effects of rare earth(RE)and DLPM on the hot cracking tendency were investigated,and the mechanism of hot cracking formation and modification in largescale ingots was revealed.The findings indicate that the addition of moderate amounts of RE lessens the tendency of hot cracking in large-scale ZK61 alloy ingots.This is mainly attributed to the addition of RE increases the content of the second phase,thus enhancing the ability of the eutectic liquid phase to feed the cracking.With the introduction of DLPM,the grain sizes are significantly refined and homogenized,and there is no obvious hot cracking observed in the ingot.This is because the coupling of the DLPM provides a more homogeneous temperature field,leading to the synchronization of the solidification process,and the consequent reduction of the casting stress,thus reducing the driving force for the formation of hot cracking.In addition,the casting conditions are modified to enhance the ability of solidification feeding and the resistance to hot cracking.This work provides theoretical and practical references for the preparation of large-scale high-quality Mg alloy ingots.
基金financial support for this work provided by the National Natural Science Foundation of China (No.52227901)。
文摘To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata,this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes.The tests involved loading the samples to 60%,70%,and 80%of their uniaxial compressive strength,followed by unloading and reloading until failure.Key parameters such as the elastic energy index and linear elasticity criteria were derived from these tests.Additionally,rock fragments were collected to calculate their initial ejection kinetic energy,serving as a measure of rockburst tendency.The classification of rockburst tendency was conducted using grading methods based on burst energy index(WET),pre-peak stored elastic energy(PES)and experimental observations.Multi-class classification and regression analyses were applied to machine learning models using experimental data to predict rockburst tendency levels.A comparative analysis of models from two libraries revealed that the Random Forest model achieved the highest accuracy in classification,while the Ada Boost Regressor model excelled in regression predictions.This study highlights that on a laboratory scale,integrating ejection kinetic energy with the unloading ratio,failure load,W_(ET)and PES through machine learning offers a highly accurate and reliable approach for determining rockburst tendency levels.
