According to the basic theory on autofrettage and according to the 4th strength theory, several parameters and their relations are studied under ideal condition, including σej/σy, the equivalent stress of total stre...According to the basic theory on autofrettage and according to the 4th strength theory, several parameters and their relations are studied under ideal condition, including σej/σy, the equivalent stress of total stresses at elastoplastic juncture; σei/σy, the equivalent stress of total stresses at inside surface; σej＇/σy, the equivalent stress of residual stresses at elastoplastic juncture; σei＇/σy, the equivalent stress of residual stresses at inside surface; and p/σy, load-bearing capacity of an autofrettaged cylinder. By theoretical study on relations between the parameters, noticeable results and laws are achieved： to satisfy ｜σei＇｜=σy. the relation between kj and k is, k^2lnkj^2-k^2-kj^2＋2=0, when k→∞, kj = √e = 1.648 72, as based on the 3rd strength theory, where k is the outside/inside radius ratio of a cylinder, kj is the ratio of elastoplastic juncture radius to inside radius of a cylinder; If the plastic region covers the whole wall of a cylinder, for compressive yield not to occur after removing autofrettage pressure, the ultimate k is k=-2.218 46 as based on the 3rd strength theory; With k=2.218 46, a cylinder＇s ultimate load-bearing capacity equals its entire yield pressure, or p/σy=21nk/√3; The maximum and optimum load-bearing capacity of an autofrettaged cylinder is just 2 times the loading which an unautofrettaged cylinder can bear elastically, or p/σy=2（k^2-1）/√3 k^2, and the limit of the load-bearing capacity of an autofrettaged cylinder is also just 2 times that of an unautofrettaged cylinder. The conclusions are the same as based on the 3rd strength theory, but some equations are different from each other.展开更多
Autofrettage is an effective measure to even distribution of stresses and raise load-bearing capacity for （ultra-）high pressure apparatus. Currently, the research on autofrettage has focused mostly on specific engin...Autofrettage is an effective measure to even distribution of stresses and raise load-bearing capacity for （ultra-）high pressure apparatus. Currently, the research on autofrettage has focused mostly on specific engineering problems, while general theoretical study is rarely done. To discover the general law contained in autofrettage theory, by the aid of the authors’ previous work and according to the third strength theory, theoretical problems about autofrettage are studied including residual stresses and their equivalent stress, total stresses and their equivalent stress, etc. Because of the equation of optimum depth of plastic zone which is presented in the authors’ previous work, the equations for the residual stresses and their equivalent stress as well as the total stress and their equivalent stress are simplified greatly. Thus the law of distribution of the residual stresses and their equivalent stress as well as the total stress and their equivalent stress and the varying tendency of these stresses are discovered. The relation among various parameters are revealed. The safe and optimum load-bearing conditions for cylinders are obtained. According to the results obtained by theoretical analysis, it is shown that if the two parameters, namely ratio of outside to inside radius, k, and depth of plastic zone, kj, meet the equation of optimum depth of plastic zone, when the pressure contained in an autofrettaged cylinder is lower than two times the initial yield pressure of the unautofrettaged cylinder, the equivalent residual stress and the equivalent total stress at the inside surface as well as the elastic-plastic juncture of a cylinder are lower than yield strength. When an autofrettaged cylinder is subjected to just two times the initial yield pressure of the unautofrettaged cylinder, the equivalent total stress within the whole plastic zone is just identically equal to the yield strength, or it is a constant. The proposed research theoretically depicts the stress state of ultra-）high pressure autofrettaged cylinder more accurately and more reasonably and provides the reference for design of （ultra-）high pressure apparatus.展开更多
Soft grippers have great potential applications in daily life,since they can compliantly grasp soft and delicate objects.However,the highly elastic fingers of most soft grippers are prone to separate from each other w...Soft grippers have great potential applications in daily life,since they can compliantly grasp soft and delicate objects.However,the highly elastic fingers of most soft grippers are prone to separate from each other while grasping objects due to their low stiffness,thus reducing the grasping stability and load-bearing capacity.To tackle this problem,inspired from the venus flytrap plant,this work proposes a mutual-hook mechanism to restrain the separation and improve the grasping performance of soft fingers.The novel soft gripper design consists of three modules,a soft finger-cot,two Soft Hook Actuators(SHAs)and two sliding mechanisms.Here,the soft finger-cot covers on the soft finger,increasing the contact area with the target object,two SHAs are fixed to the left and right sides of the finger-cot,and the sliding mechanisms are designed to make SHAs stretch flexibly.Experiments demonstrate that the proposed design can restrain the separation of soft fingers substantially,and the soft fingers with the finger-cots can grasp objects three times heavier than the soft fingers without the proposed design.The proposed design can provide invaluable insights for soft fingers to restrain the separation while grasping,thus improving the grasping stability and the load-bearing capacity.展开更多
In several parts of the world, disposal of waste materials such as fly ash is a great problem. Application of waste materials as structural fills in foundations is one of the best solutions to disposal problems, becau...In several parts of the world, disposal of waste materials such as fly ash is a great problem. Application of waste materials as structural fills in foundations is one of the best solutions to disposal problems, because wastes can be used in large volumes in such applications. There may be difficulty due to poor load-bearing capacity of fly ash, especially when footing rests on the top of the fly ash fill slope. Inclusion of polymeric reinforcements as horizontal sheets within the fill may be one of the most viable solutions to improving the load-bearing capacity of reinforced fly ash slope, and it is particularly important for the situations where foundations need to be located either on the top of a slope or on slope itself. The present work is aimed at investigating the efficacy of a single layer of reinforcement in improving the lo, ad-bearing capacity when it gets incorporated within the body of a model fly ash embankment slope. An increase in load bearing capacity due to the incorporation of reinforcement in the model slope was found by conducting laboratory tests. Experimental results were compared by numerical values obtained using software GEO5 and PLAXIS.展开更多
The present study develops a novel type of active joint node-bolt fasten wedge(BFW)active joints,aiming to investigate the load-bearing capacity of a BFW joint in a quantitative way and put forward precise formulas fo...The present study develops a novel type of active joint node-bolt fasten wedge(BFW)active joints,aiming to investigate the load-bearing capacity of a BFW joint in a quantitative way and put forward precise formulas for its yield load and compression rigidity.To achieve this,indoor axial loading tests were conducted on two BFW joints,accompanied by a set of numerical simulations with the finite element approach implemented in ABAQUS.Parametric research was then conducted to assess the impact of various factors on the yield load and initial compression rigidity of BFW joints,leading to the derivation of precise calculation formulas for accurate prediction of these parameters.The key findings indicate that enhancing the bolt strength from 10.9 to 12.9 significantly improves mechanical performance.Under axial compression,the final bearing force,yield load,and initial compression rigidity increase by 0.86,1.06,and 0.15 times,respectively.Numerical models accurately predict joint behavior under axial force,confirming their reliability.Parameter studies reveal that increasing web and eaves thickness,bolt strength,and diameter improves bearing capacity,while splint thickness has little effect.The fitting formulas introduced can precisely estimate yield load and rigidity,providing practical value for engineering applications.展开更多
Roof pre-fracture poses a considerable risk during the re-mining of residual coal above abandoned roadways,threatening the safety of the mining faces.This study employs a Winkler foundation beam model for mechanical a...Roof pre-fracture poses a considerable risk during the re-mining of residual coal above abandoned roadways,threatening the safety of the mining faces.This study employs a Winkler foundation beam model for mechanical analysis of roof structures and adopts a multivariate nonlinear analysis approach to explore the synergistic load-bearing effects within the'coal pillar-support-backfill body'system during the fill and re-mining processes above these roadways.The findings demonstrate that backfill mining significantly reduces stress concentrations in coal pillars and reduces excessive bending moments in roofs near abandoned roadways.The roof deflection equation incorporates three critical factors affecting stability during backfill mining:the width of the coal pillar(L_(3)),the working resistance of the support(q_(z)),and the elastic foundation coefficient of the backfill material(kcÞ.Under single-factor conditions,the impact sequence on roof stability in the coal pillar zone is·k_(c)>L_(3)>q_(z).Further,multivariate nonlinear analysis reveals the interactions within the'coal-support-backfill'structure,indicating that in terms of roof control,the interaction terms are ordered as L_(3)·k_(c)>q_(z)·k_(c)>L_(3)q_(z).Therefore,priority should be given to adjusting the coal pillar width and backfill strength,followed by modifications to the support resistance and backfill strength during the recovery of abandoned roadways.An improved understanding of these interactions will help optimize strategies for the recovery of residual coal through abandoned roadways,thereby enhancing the stability and safety of mining operations under complex geological conditions.展开更多
Background:The trajectory of intrinsic capacity(IC)among the older population is characterized by its diversity and is predictive of adverse health outcomes such as disability,nursing home admission,decline in quality...Background:The trajectory of intrinsic capacity(IC)among the older population is characterized by its diversity and is predictive of adverse health outcomes such as disability,nursing home admission,decline in quality of life,and mortality.Gaining an understanding of the trajectory of IC and the factors that influence it is of paramount importance for fostering healthy aging.This research is focused on exploring the trajectory of IC among older adults in China and examining the factors that influence it.Methods:This observational longitudinal cohort study leveraged data from the China Health and Retirement Longitudinal Study(CHARLS),which was conducted in the years 2011,2013,and 2015.For the purpose of this analysis,a total of 2,233 participants who were aged 60 and over were included.A Growth Mixture Model(GMM)was utilized to define trajectory categories for IC.Influential factors were ascertained based on the health ecology model,and binary logistic regression analysis was utilized to investigate the factors linked with the different trajectory categories.Results:Two distinct trajectory classes of IC were identified:Class 1,the normal-stable group,encompassed 90.4%of the elderly population,while Class 2,the declining group,made up 9.6%.Advanced age and a history of stroke were found to be significantly associated with Class 2.High scores in activities of daily living(ADL),employment status,receiving primary or junior high school education,and residence in the East or Central regions of China were significantly linked with Class 1.Conclusion:The trajectory of IC among older Chinese adults is marked by its heterogeneity.Advanced age and a history of stroke are significant risk factors for a declining IC trajectory,while higher ADL scores,being employed,receiving primary or junior high school education,and residing in the East or Central regions of China are protective factors associated with a stable IC trajectory.Healthcare institutions must closely monitor IC levels and understand these trajectory patterns to implement personalized and targeted interventions promptly to maintain IC at a healthy level and advocate for healthy aging.展开更多
Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures ...Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures were prepared through digital light processing(DLP)3D printing,polymer-derived ceramics(PDCs),chemical vapor infiltration(CVI),and oxidation technologies.The incorporation of the CVISiC phase effectively increases the dissipation capability,while the synergistic interaction between the gyroid structure and SiO_(2)phase significantly improves impedance matching performance.The SiOC/SiC/SiO_(2)composite achieved a minimum reflection loss(RL min)of-62.2 d B at 4.3 mm,and the effective absorption bandwidth(EAB)covered the X-band,with a thickness range of 4.1 mm-4.65 mm.The CST simulation results explain the broadband and low-frequency absorption characteristics,with an EAB of 8.4 GHz(9.6-18 GHz)and an RL min of-21.5 dB at 5 GHz.The excellent EM wave attenuation performance is associated primarily with polarization loss,conduction loss,the gyroid structure's enhancement of multiple reflections and scattering of EM waves,and the resonance effect between the structural units.The SiOC/SiC/SiO_(2)composite also demonstrated strong mechanical properties,with a maximum compressive failure strength of 31.6 MPa in the height direction.This work opens novel prospects for the development of multifunctional structural wave-absorbing materials suitable for broadband microwave absorption and load-bearing properties.展开更多
Large-scale access of distributed photovoltaic(PV)in distribution networks(DNs),if not properly evaluated,brings several operational problems.Uncertainties arising from both PV outputs and load demand significantly im...Large-scale access of distributed photovoltaic(PV)in distribution networks(DNs),if not properly evaluated,brings several operational problems.Uncertainties arising from both PV outputs and load demand significantly impact evaluation results.To address this issue,this paper proposes a possibilistic approach to evaluate PV hosting capacity(PVHC).First,possibility distribution is used to model load demand in order to reflect uncertainties associated with human factor,whereas the interval model is applied to deal with uncertainties of PV outputs.Second,a voltage deterioration index is proposed considering overvoltage risk of entire system on time scale.After that,possibilistic PVHC evaluation method based on this index is proposed.A 6-bus system is used to illustrate advantages of the proposed method,followed by a discussion of role of PVHC possibility distribution in actual decision-making of utilities.Moreover,sensitivity of simulation parameters is analyzed to reduce computational burden.Finally,the proposed method is tested on the IEEE 123-bus DN to validate adaptability to a larger system and to analyze impact of PVHC results against different acceptable values set by utilities.展开更多
China has set its economic growth target for 2026 in the range of 4.5-5 percent.After three consecutive years of aiming for growth of around 5 percent,the slightly adjusted range reflects a prudent assessment of a com...China has set its economic growth target for 2026 in the range of 4.5-5 percent.After three consecutive years of aiming for growth of around 5 percent,the slightly adjusted range reflects a prudent assessment of a complex global environment while still signalling a commitment to stable development.展开更多
Background:Intrinsic capacity reflects the overall health status of older adults and decline in intrinsic abilities can lead to adverse health outcomes.However,empirical studies examining the association between digit...Background:Intrinsic capacity reflects the overall health status of older adults and decline in intrinsic abilities can lead to adverse health outcomes.However,empirical studies examining the association between digital health literacy,health-promoting lifestyles and intrinsic capacity are scarce.Methods:A cross-sectional study was conducted.Using convenience sampling method,371 older adults were recruited from communities.Multidimensional intrinsic capacity,digital health literacy,health promoting lifestyle and sociodemographic information were measured.Results:The intrinsic capacity of older adults scored 3.75±1.10.The prevalences of declined cognitive capacity,psychological capacity,sensory capacity,vitality,and locomotor capacity were 13.7%,24.3%,19.1%,14.8%,53.1%,respectively.The multiple regression analysis revealed that age(β=−0.253),only living with children and/or grandchildren(β=0.249),current working status(β=−0.132),number of chronic diseases(β=−0.149),frequency of Internet usage(β=0.193),the domain of ability to acquire and evaluate digital health information(β=0.197)in digital health literacy,and the domain of nutrition(β=0.171)in health-promoting lifestyle were the significant factors influencing intrinsic capacity,explaining 27.1%of the variance.Conclusion:Digital health literacy and health-promoting lifestyle have a significant impact on intrinsic capacity.Enhancing digital health literacy and advocating a health-promoting lifestyle are critical to promoting intrinsic capacity for community-dwelling older adults.展开更多
Although wind energy is volatile,the output of a wind-storage plant is partially dispatchable,making it a promising paradigm on the generation side.A grid-friendly wind-storage plant ought to be able to continuously o...Although wind energy is volatile,the output of a wind-storage plant is partially dispatchable,making it a promising paradigm on the generation side.A grid-friendly wind-storage plant ought to be able to continuously output the desired power over a certain period of time.This paper proposes a dependable dynamic capacity provision scheme of a wind-storage plant over a daily horizon.It stipulates a minimum number of periods during which the committed capacity must be fulfilled and a maximum mismatch during the remaining periods when the desired power output is not achievable.In the general case,the day-ahead piecewise constant capacity provision results in a two-stage stochastic program formulated as a mixed-integer linear program.Specifically,for constant capacity provision,a decomposition algorithm is developed to determine the global optimal solution,and the complexity grows linearly with the number of scenarios.Given the committed capacity trajectory,the real-time operation problem is modeled as a four-state stochastic dynamic program.The discrete state-action values are derived recursively via the principle of optimality.Real-time dispatch actions are generated by using the action-value tabular leveraging inexact ultra-short-term forecasts.Numerical tests over one year demonstrate that the proposed method successfully fulfills reliable operation on 355 days and achieve an optimality gap of 9.47%compared with the ex-post optimum,which is comparable to model predictive control using exact 2–3-hour-ahead wind power forecasts.展开更多
Research on high-speed railways is a relatively new yet highly significant field in Vietnam.Among its key components,train control signaling plays a critical role,as it directly affects various interconnected systems,...Research on high-speed railways is a relatively new yet highly significant field in Vietnam.Among its key components,train control signaling plays a critical role,as it directly affects various interconnected systems,including infrastructure,traction power supply,operational planning,and overall railway safety.This article focuses on evaluating the capacity of the line based on the types of signals suitable for high-speed railways that have been effectively implemented in several European countries and successfully adapted in China.The research and simulation are conducted using MATLAB software,a reliable and widely adopted tool in the scientific community.The findings demonstrate that under normal conditions,the European Railway Traffic Management System/European Train Control System(ERTMS/ETCS)Level 2 signaling can support up to 23.7485 trains/hour/direction.Meanwhile,ERTMS/ETCS Level 3 with full moving block can accommodate up to 30.8735 trains/hour/direction,and ERTMS/ETCS Level 3 with fixed virtual blocks up to 29.4694 trains/hour/direction.In emergency scenarios,ERTMS/ETCS Level 3 with full moving block reduces headway by 33.27%compared to CTCS Level 3,while ERTMS/ETCS Level 3 with fixed virtual blocks achieves a 28.78%reduction.Overall,the ERTMS/ETCS Level 3 emerges as a state-of-the-art signaling technology offering high capacity and operational efficiency,and is recommended as a forward-looking solution for future implementation in Vietnam.展开更多
Purpose-This study investigates the impact of flagship trains on high-speed railway capacity utilization and develops a brand value-oriented optimization framework that balances service quality enhancement with operat...Purpose-This study investigates the impact of flagship trains on high-speed railway capacity utilization and develops a brand value-oriented optimization framework that balances service quality enhancement with operational efficiency.Design/methodology/approach-A mathematical optimization model based on integer programming is developed,incorporating flagship train constraints into capacity optimization.Case studies compare scenarios with and without flagship train considerations using the Beijing-Shanghai High-Speed Railway data across 20 experimental groups.Findings-Operating flagship trains with hourly departure constraints results in an average decrease of 0.9 trains and an 8.4%reduction in capacity utilization rate.When scheduling 2 flagship trains within a 2-h timeframe,capacity utilization decreases from 86.43%to 83.73%,quantifying the trade-off between brand positioning and operational capacity.Originality/value-This research provides the first quantitative framework for brand value-oriented railway capacity optimization,establishing clear definitions for flagship trains and mathematical foundations for evaluating service quality versus efficiency trade-offs.The findings offer practical decision support for railway operators balancing competitive positioning with capacity maximization.展开更多
Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particul...Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particularly those associated with antioxidant defense,intestinal development and host-microbiota interactions.Method A total of 1001-day-old Pekin ducklings were used in this study with 50 DHAV-3 susceptible and resistant ducks,respectively.Samples were collected at 7 days post-hatching(D7),D21 and D42,10 birds per group.We compared DHAV-3 resistant and susceptible ducks during early development with respect to immune organ indices,antioxidant capacity,intestinal morphology,barrier-related gene expression and cecal microbiota.Result Resistant ducks exhibited higher spleen indices and stronger antioxidant capacity,characterized by increased superoxide dismutase,reduced glutathione,and total antioxidant capacity,along with lower malondialdehyde levels at D7 and D21.In contrast,susceptible ducks showed compensatory thymus hypertrophy and delayed development of antioxidant defense and intestinal maturation.Ileal morphology revealed greater villus height and width with more regular arrangement in resistant ducks at D7,whereas these differences diminished at D21 and D42.Gene expression analysis demonstrated higher early expression of the tight junction proteins CLDN1 and CLDN3 in resistant ducks,while susceptible ducks displayed elevated MUC2 and OCLN,suggesting stress induced compensatory responses.Cecal microbiota analysis revealed distinct colonization patterns in early development.Resistant ducks were enriched with Firmicutes and beneficial genera such as Enterococcus and Lactobacillus,whereas susceptible ducks harbored higher abundances of Bacteroidota and potentially opportunistic taxa.Microbial diversity increased with age in both groups,but resistant ducks displayed more orderly succession and enrichment of SCFA producing genera,including Subdoligranulum and Phascolarctobacterium,which positively correlated with plasma antioxidant indices.Conclusion DHAV-3 resistant ducks exhibit early advantages in antioxidant defense,intestinal barrier development and colonization by beneficial microbiota,which collectively contribute to enhanced disease resistance.These findings highlight the synergistic roles of host physiology and gut microbiota in shaping resistance.In the future,integrating genomic selection with microbiota modulation and antioxidant interventions may accelerate the breeding of highly resistant duck lines and provide scientific evidence and practical strategies for controlling duck viral hepatitis.展开更多
China Standardization:Can you please briefly introduce ISO,its international standards as well as your scope of work?Rachel Miller Prada:ISO is an independent non-governmental organization dedicated to developing inte...China Standardization:Can you please briefly introduce ISO,its international standards as well as your scope of work?Rachel Miller Prada:ISO is an independent non-governmental organization dedicated to developing international standards.Currently,ISO has 175 member bodies,representing 175 countries that participate in its standard development work.We have a portfolio of over 24,000 international standards,with around 100 new standards issued or existing ones revised every month.The ultimate goal of our standardization work is to support the achievement of the United Nations Sustainable Development Goals(SDGs).Every standard we develop and every task I undertake in my role contributes to these global objectives.展开更多
In this paper,we propose a novel probabilistic method for predicting the undrained bearing capacity of spatially variable soils.Our approach combines a Gaussian process regression(GPR)-based surrogate model with rando...In this paper,we propose a novel probabilistic method for predicting the undrained bearing capacity of spatially variable soils.Our approach combines a Gaussian process regression(GPR)-based surrogate model with random cell-based smoothed finite analysis.The Gaussian process emulator(GPE)serves as a statistical tool for making predictions from a data set.First,we validate the accuracy and efficiency of kinematic limit analysis using the cell-based smoothed finite element method(CS-FEM)against the standard finite element method(FEM)and edge-based smoothed FEM(ES-FEM).The numerical results demonstrate that the CS-FEM framework surpasses traditional numerical approaches,establishing its reliability in computing collapse loads.Subsequently,we conduct several hundred simulations to develop a surrogate model for predicting the undrained bearing capacity of shallow foundations.By utilizing various kernel functions,we enhance the accuracy of the GPE in these predictions.This method offers a practical and efficient solution,effectively addressing multiple uncertainties.Numerical results indicate that the GPE significantly boosts computational efficiency,achieving satisfactory outcomes within minutes compared to the days required for conventional simulations.Notably,the mean absolute percentage error(MAPE)decreases from 2.38%to 1.82%for rough foundations when employing Matérn and rational quadratic kernel functions,respectively.Additionally,combining different kernel functions further enhances the accuracy of collapse load predictions.展开更多
To achieve the goals of sustainable development of the energy system and the construction of a lowcarbon society,this study proposes a multi-energy storage collaborative optimization strategy for industrial park that ...To achieve the goals of sustainable development of the energy system and the construction of a lowcarbon society,this study proposes a multi-energy storage collaborative optimization strategy for industrial park that integrates the laddered carbon trading mechanism with demand response.Firstly,a dual dimensional DR model is constructed based on the characteristics of load elasticity.The alternativeDRenables flexible substitution of energy loads through complementary conversion of electricity/heat/cold multi-energy sources,while the price DR relies on timeof-use electricity price signals to guide load spatiotemporal migration;Secondly,the LCT mechanism is introduced to achieve optimal carbon emission costs through a tiered carbon quota allocation mechanism.On this basis,an optimization decision model is established with the core objective of maximizing the annual net profit of the park.The objective function takes into account energy sales revenue,generator unit costs,and investment and operation costs of multiple types of energy storage facilities.Themodel constraint system covers three key dimensions:dynamic operation constraints of power generation units,including unit output limits,ramping capability,and minimum start-stop time;the physical boundary of an electric/hot/cold multi-energy storage system involves energy storage capacity and charge/discharge efficiency;The multi-energy network coupling balance equation ensures that the energy conversion and transmission process satisfies the law of conservation of energy.Using CPLEX mathematical programming solver for simulation verification,construct an energy storage capacity configuration decision process that includes LCT-DR synergistic effect.The research results show that compared with the traditional single energy storage configuration mode,this strategy effectively enhances the economic feasibility and engineering practicality of industrial park operation by coordinating demand side resource scheduling and finely controlling carbon costs,while maintaining stable system operation.Its methodological framework provides a technical path that combines theoretical rigor and practical operability for the low-carbon transformation of regional integrated energy systems.展开更多
Atmospheric oxidation capacity(AOC)refers to the oxidation capacity of atmospheric chemical processes for major pollutants.A comprehensive observation campaign was conducted on a typical PM_(2.5)pollution event in Uru...Atmospheric oxidation capacity(AOC)refers to the oxidation capacity of atmospheric chemical processes for major pollutants.A comprehensive observation campaign was conducted on a typical PM_(2.5)pollution event in Urumqi,Northwest China,from January 15 to February 15,2024.Four typical cases representing PM_(2.5)levels from non-polluted to heavily polluted periods were selected to estimate AOC,OH reactivity,their relationship with secondary components,and the HO_(x)budget in PM_(2.5)using the Framework for 0-D Atmospheric Modeling model.Aromatics and alkanes contributed 54%-79%and 18%-46%of secondary organic aerosols(SOA)formation,respectively.The sulfur oxidation ratio(SOR)and nitrogen oxidation ratio(NOR)increased with rising PM_(2.5)levels.As AOC increased,SOR showed the same trend,while NOR and SOA decreased slightly,and ammonia oxidation ratio values remained almost unchanged.OH radicals were the primary oxidants during the daytime,whereas NO_(3)played a dominant role at nighttime.CO(24%-51%),NO2(27%-34%),and alkenes(7%-12%)were the dominant contributors to OH reactivity.The HO_(2)+NO reaction pathway contributes 67%-84%to the production of OH,while Others(including carbonyl compounds photolysis,the permutation reactions of RO2,etc.),RO_(2)+NO and OH+CO reaction pathways were the main pathways for HO2 production.A comprehensive understanding of the interactions among AOC,SOA,and radical cycling is crucial for formulating effective air quality management strategies aimed at mitigating secondary pollution under diverse atmospheric conditions.展开更多
Objective:To explore the application effect of combined exercise intervention based on the hospital-community-family model on intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney...Objective:To explore the application effect of combined exercise intervention based on the hospital-community-family model on intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney disease.Methods:Using convenience sampling,100 elderly patients with diabetes mellitus complicated by chronic kidney disease who received treatment in the endocrinology department of a tertiary A-level hospital from May 2024 to May 2025 were selected as the study subjects.They were randomly divided into an experimental group(50 cases)and a control group(50 cases)using a random number table method.The control group received routine health education and telephone follow-up,while the experimental group,in addition to the control group’s interventions,underwent combined exercise intervention based on the hospital-community-family model.Remote medical guidance was utilized to monitor and study the application effect of exercise intervention on intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney disease.Fasting blood glucose,2-hour postprandial blood glucose,glomerular filtration rate,6-minute walk distance,and scores in five dimensions of intrinsic capacity(exercise,cognition,psychology,vitality,and sensation)were measured before the intervention,at 4 weeks of intervention,and at 12 weeks of intervention for both groups.Results:Before the exercise intervention,there were no statistically significant differences(p>0.05)between the two groups in terms of fasting blood glucose,2-hour postprandial blood glucose,glomerular filtration rate,6-minute walk distance,and scores across five dimensions of intrinsic capacity:mobility,cognition,psychology,vitality,and sensation.After 12 weeks of intervention,the experimental group demonstrated significantly higher scores than the control group in glomerular filtration rate,6-minute walk distance,and the dimensions of mobility,cognition,and vitality within intrinsic capacity,with all differences being statistically significant(p<0.05).Conversely,the experimental group showed significantly lower scores than the control group in fasting blood glucose,2-hour postprandial blood glucose,and the psychological dimension of intrinsic capacity,with these differences also being statistically significant(p<0.05).Conclusion:Continuous nursing care utilizing telemedicine based on a hospital-community-family model combined with exercise intervention can effectively enhance exercise tolerance and intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney disease,thereby improving their quality of life.The effectiveness of the intervention is positively correlated with the duration of the intervention.展开更多
文摘According to the basic theory on autofrettage and according to the 4th strength theory, several parameters and their relations are studied under ideal condition, including σej/σy, the equivalent stress of total stresses at elastoplastic juncture; σei/σy, the equivalent stress of total stresses at inside surface; σej＇/σy, the equivalent stress of residual stresses at elastoplastic juncture; σei＇/σy, the equivalent stress of residual stresses at inside surface; and p/σy, load-bearing capacity of an autofrettaged cylinder. By theoretical study on relations between the parameters, noticeable results and laws are achieved： to satisfy ｜σei＇｜=σy. the relation between kj and k is, k^2lnkj^2-k^2-kj^2＋2=0, when k→∞, kj = √e = 1.648 72, as based on the 3rd strength theory, where k is the outside/inside radius ratio of a cylinder, kj is the ratio of elastoplastic juncture radius to inside radius of a cylinder; If the plastic region covers the whole wall of a cylinder, for compressive yield not to occur after removing autofrettage pressure, the ultimate k is k=-2.218 46 as based on the 3rd strength theory; With k=2.218 46, a cylinder＇s ultimate load-bearing capacity equals its entire yield pressure, or p/σy=21nk/√3; The maximum and optimum load-bearing capacity of an autofrettaged cylinder is just 2 times the loading which an unautofrettaged cylinder can bear elastically, or p/σy=2（k^2-1）/√3 k^2, and the limit of the load-bearing capacity of an autofrettaged cylinder is also just 2 times that of an unautofrettaged cylinder. The conclusions are the same as based on the 3rd strength theory, but some equations are different from each other.
基金supported by Scientific Research Fund of Hunan Provincial Education Department(Grant No. 12A087)Innovation Fund for Technology Based Firms(Grant No. 09C26214305047)
文摘Autofrettage is an effective measure to even distribution of stresses and raise load-bearing capacity for （ultra-）high pressure apparatus. Currently, the research on autofrettage has focused mostly on specific engineering problems, while general theoretical study is rarely done. To discover the general law contained in autofrettage theory, by the aid of the authors’ previous work and according to the third strength theory, theoretical problems about autofrettage are studied including residual stresses and their equivalent stress, total stresses and their equivalent stress, etc. Because of the equation of optimum depth of plastic zone which is presented in the authors’ previous work, the equations for the residual stresses and their equivalent stress as well as the total stress and their equivalent stress are simplified greatly. Thus the law of distribution of the residual stresses and their equivalent stress as well as the total stress and their equivalent stress and the varying tendency of these stresses are discovered. The relation among various parameters are revealed. The safe and optimum load-bearing conditions for cylinders are obtained. According to the results obtained by theoretical analysis, it is shown that if the two parameters, namely ratio of outside to inside radius, k, and depth of plastic zone, kj, meet the equation of optimum depth of plastic zone, when the pressure contained in an autofrettaged cylinder is lower than two times the initial yield pressure of the unautofrettaged cylinder, the equivalent residual stress and the equivalent total stress at the inside surface as well as the elastic-plastic juncture of a cylinder are lower than yield strength. When an autofrettaged cylinder is subjected to just two times the initial yield pressure of the unautofrettaged cylinder, the equivalent total stress within the whole plastic zone is just identically equal to the yield strength, or it is a constant. The proposed research theoretically depicts the stress state of ultra-）high pressure autofrettaged cylinder more accurately and more reasonably and provides the reference for design of （ultra-）high pressure apparatus.
基金funded by the National Natural Science Foundation of China under Grant 62073305 and the Natural Science Foundation of Hubei Province under Grant 2022CFA041.
文摘Soft grippers have great potential applications in daily life,since they can compliantly grasp soft and delicate objects.However,the highly elastic fingers of most soft grippers are prone to separate from each other while grasping objects due to their low stiffness,thus reducing the grasping stability and load-bearing capacity.To tackle this problem,inspired from the venus flytrap plant,this work proposes a mutual-hook mechanism to restrain the separation and improve the grasping performance of soft fingers.The novel soft gripper design consists of three modules,a soft finger-cot,two Soft Hook Actuators(SHAs)and two sliding mechanisms.Here,the soft finger-cot covers on the soft finger,increasing the contact area with the target object,two SHAs are fixed to the left and right sides of the finger-cot,and the sliding mechanisms are designed to make SHAs stretch flexibly.Experiments demonstrate that the proposed design can restrain the separation of soft fingers substantially,and the soft fingers with the finger-cots can grasp objects three times heavier than the soft fingers without the proposed design.The proposed design can provide invaluable insights for soft fingers to restrain the separation while grasping,thus improving the grasping stability and the load-bearing capacity.
文摘In several parts of the world, disposal of waste materials such as fly ash is a great problem. Application of waste materials as structural fills in foundations is one of the best solutions to disposal problems, because wastes can be used in large volumes in such applications. There may be difficulty due to poor load-bearing capacity of fly ash, especially when footing rests on the top of the fly ash fill slope. Inclusion of polymeric reinforcements as horizontal sheets within the fill may be one of the most viable solutions to improving the load-bearing capacity of reinforced fly ash slope, and it is particularly important for the situations where foundations need to be located either on the top of a slope or on slope itself. The present work is aimed at investigating the efficacy of a single layer of reinforcement in improving the lo, ad-bearing capacity when it gets incorporated within the body of a model fly ash embankment slope. An increase in load bearing capacity due to the incorporation of reinforcement in the model slope was found by conducting laboratory tests. Experimental results were compared by numerical values obtained using software GEO5 and PLAXIS.
基金the financial support provided by Beijing Natural Science Foundation(Grant No.8222005)the Natural Science Foundation of China(Grant No.51978018)Science and Technology Funding Scheme for the Third Construction Engineering Company Ltd.of China Construction Second Engineering Bureau(Grant No.CSCEC2b3c-2021-K-65).
文摘The present study develops a novel type of active joint node-bolt fasten wedge(BFW)active joints,aiming to investigate the load-bearing capacity of a BFW joint in a quantitative way and put forward precise formulas for its yield load and compression rigidity.To achieve this,indoor axial loading tests were conducted on two BFW joints,accompanied by a set of numerical simulations with the finite element approach implemented in ABAQUS.Parametric research was then conducted to assess the impact of various factors on the yield load and initial compression rigidity of BFW joints,leading to the derivation of precise calculation formulas for accurate prediction of these parameters.The key findings indicate that enhancing the bolt strength from 10.9 to 12.9 significantly improves mechanical performance.Under axial compression,the final bearing force,yield load,and initial compression rigidity increase by 0.86,1.06,and 0.15 times,respectively.Numerical models accurately predict joint behavior under axial force,confirming their reliability.Parameter studies reveal that increasing web and eaves thickness,bolt strength,and diameter improves bearing capacity,while splint thickness has little effect.The fitting formulas introduced can precisely estimate yield load and rigidity,providing practical value for engineering applications.
基金support from National Natural Science Foundation of China(Grant No.52474142)The National Science Fund for Distinguished Young Scholars(No.51925402),Chinathe China Postdoctoral Science Foundation(Grant No.2021M702049).
文摘Roof pre-fracture poses a considerable risk during the re-mining of residual coal above abandoned roadways,threatening the safety of the mining faces.This study employs a Winkler foundation beam model for mechanical analysis of roof structures and adopts a multivariate nonlinear analysis approach to explore the synergistic load-bearing effects within the'coal pillar-support-backfill body'system during the fill and re-mining processes above these roadways.The findings demonstrate that backfill mining significantly reduces stress concentrations in coal pillars and reduces excessive bending moments in roofs near abandoned roadways.The roof deflection equation incorporates three critical factors affecting stability during backfill mining:the width of the coal pillar(L_(3)),the working resistance of the support(q_(z)),and the elastic foundation coefficient of the backfill material(kcÞ.Under single-factor conditions,the impact sequence on roof stability in the coal pillar zone is·k_(c)>L_(3)>q_(z).Further,multivariate nonlinear analysis reveals the interactions within the'coal-support-backfill'structure,indicating that in terms of roof control,the interaction terms are ordered as L_(3)·k_(c)>q_(z)·k_(c)>L_(3)q_(z).Therefore,priority should be given to adjusting the coal pillar width and backfill strength,followed by modifications to the support resistance and backfill strength during the recovery of abandoned roadways.An improved understanding of these interactions will help optimize strategies for the recovery of residual coal through abandoned roadways,thereby enhancing the stability and safety of mining operations under complex geological conditions.
基金China Health and Retirement Longitudinal Study(CHARLS)the 2022-2023 Nursing Research Project of Chinese Medical Association Publishing House(Grant No.CMAPH-NRD2022024)。
文摘Background:The trajectory of intrinsic capacity(IC)among the older population is characterized by its diversity and is predictive of adverse health outcomes such as disability,nursing home admission,decline in quality of life,and mortality.Gaining an understanding of the trajectory of IC and the factors that influence it is of paramount importance for fostering healthy aging.This research is focused on exploring the trajectory of IC among older adults in China and examining the factors that influence it.Methods:This observational longitudinal cohort study leveraged data from the China Health and Retirement Longitudinal Study(CHARLS),which was conducted in the years 2011,2013,and 2015.For the purpose of this analysis,a total of 2,233 participants who were aged 60 and over were included.A Growth Mixture Model(GMM)was utilized to define trajectory categories for IC.Influential factors were ascertained based on the health ecology model,and binary logistic regression analysis was utilized to investigate the factors linked with the different trajectory categories.Results:Two distinct trajectory classes of IC were identified:Class 1,the normal-stable group,encompassed 90.4%of the elderly population,while Class 2,the declining group,made up 9.6%.Advanced age and a history of stroke were found to be significantly associated with Class 2.High scores in activities of daily living(ADL),employment status,receiving primary or junior high school education,and residence in the East or Central regions of China were significantly linked with Class 1.Conclusion:The trajectory of IC among older Chinese adults is marked by its heterogeneity.Advanced age and a history of stroke are significant risk factors for a declining IC trajectory,while higher ADL scores,being employed,receiving primary or junior high school education,and residing in the East or Central regions of China are protective factors associated with a stable IC trajectory.Healthcare institutions must closely monitor IC levels and understand these trajectory patterns to implement personalized and targeted interventions promptly to maintain IC at a healthy level and advocate for healthy aging.
基金financially supported by National Natural Science Foundation of China(Grant Nos.12141203,52202083,W2421013)the Natural Science Foundation Project of Shaanxi Province(Grant No.2024JC-YBMS-450)+1 种基金the Sichuan Science and Technology Program(Grant No.2024YFHZ0265)the Open Project of High-end Equipment Advanced Materials and Manufacturing Technology Laboratory(Grant No.2023KFKT0005)。
文摘Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures were prepared through digital light processing(DLP)3D printing,polymer-derived ceramics(PDCs),chemical vapor infiltration(CVI),and oxidation technologies.The incorporation of the CVISiC phase effectively increases the dissipation capability,while the synergistic interaction between the gyroid structure and SiO_(2)phase significantly improves impedance matching performance.The SiOC/SiC/SiO_(2)composite achieved a minimum reflection loss(RL min)of-62.2 d B at 4.3 mm,and the effective absorption bandwidth(EAB)covered the X-band,with a thickness range of 4.1 mm-4.65 mm.The CST simulation results explain the broadband and low-frequency absorption characteristics,with an EAB of 8.4 GHz(9.6-18 GHz)and an RL min of-21.5 dB at 5 GHz.The excellent EM wave attenuation performance is associated primarily with polarization loss,conduction loss,the gyroid structure's enhancement of multiple reflections and scattering of EM waves,and the resonance effect between the structural units.The SiOC/SiC/SiO_(2)composite also demonstrated strong mechanical properties,with a maximum compressive failure strength of 31.6 MPa in the height direction.This work opens novel prospects for the development of multifunctional structural wave-absorbing materials suitable for broadband microwave absorption and load-bearing properties.
基金supported by the National Key R&D Program of China(2018YFB0904700).
文摘Large-scale access of distributed photovoltaic(PV)in distribution networks(DNs),if not properly evaluated,brings several operational problems.Uncertainties arising from both PV outputs and load demand significantly impact evaluation results.To address this issue,this paper proposes a possibilistic approach to evaluate PV hosting capacity(PVHC).First,possibility distribution is used to model load demand in order to reflect uncertainties associated with human factor,whereas the interval model is applied to deal with uncertainties of PV outputs.Second,a voltage deterioration index is proposed considering overvoltage risk of entire system on time scale.After that,possibilistic PVHC evaluation method based on this index is proposed.A 6-bus system is used to illustrate advantages of the proposed method,followed by a discussion of role of PVHC possibility distribution in actual decision-making of utilities.Moreover,sensitivity of simulation parameters is analyzed to reduce computational burden.Finally,the proposed method is tested on the IEEE 123-bus DN to validate adaptability to a larger system and to analyze impact of PVHC results against different acceptable values set by utilities.
文摘China has set its economic growth target for 2026 in the range of 4.5-5 percent.After three consecutive years of aiming for growth of around 5 percent,the slightly adjusted range reflects a prudent assessment of a complex global environment while still signalling a commitment to stable development.
基金funded by the College Students’Innovation and Entrepreneurship Program(X2024110650385).
文摘Background:Intrinsic capacity reflects the overall health status of older adults and decline in intrinsic abilities can lead to adverse health outcomes.However,empirical studies examining the association between digital health literacy,health-promoting lifestyles and intrinsic capacity are scarce.Methods:A cross-sectional study was conducted.Using convenience sampling method,371 older adults were recruited from communities.Multidimensional intrinsic capacity,digital health literacy,health promoting lifestyle and sociodemographic information were measured.Results:The intrinsic capacity of older adults scored 3.75±1.10.The prevalences of declined cognitive capacity,psychological capacity,sensory capacity,vitality,and locomotor capacity were 13.7%,24.3%,19.1%,14.8%,53.1%,respectively.The multiple regression analysis revealed that age(β=−0.253),only living with children and/or grandchildren(β=0.249),current working status(β=−0.132),number of chronic diseases(β=−0.149),frequency of Internet usage(β=0.193),the domain of ability to acquire and evaluate digital health information(β=0.197)in digital health literacy,and the domain of nutrition(β=0.171)in health-promoting lifestyle were the significant factors influencing intrinsic capacity,explaining 27.1%of the variance.Conclusion:Digital health literacy and health-promoting lifestyle have a significant impact on intrinsic capacity.Enhancing digital health literacy and advocating a health-promoting lifestyle are critical to promoting intrinsic capacity for community-dwelling older adults.
基金supported by the Smart Grid-National Science and Technology Major Project of China(2024ZD0802000).
文摘Although wind energy is volatile,the output of a wind-storage plant is partially dispatchable,making it a promising paradigm on the generation side.A grid-friendly wind-storage plant ought to be able to continuously output the desired power over a certain period of time.This paper proposes a dependable dynamic capacity provision scheme of a wind-storage plant over a daily horizon.It stipulates a minimum number of periods during which the committed capacity must be fulfilled and a maximum mismatch during the remaining periods when the desired power output is not achievable.In the general case,the day-ahead piecewise constant capacity provision results in a two-stage stochastic program formulated as a mixed-integer linear program.Specifically,for constant capacity provision,a decomposition algorithm is developed to determine the global optimal solution,and the complexity grows linearly with the number of scenarios.Given the committed capacity trajectory,the real-time operation problem is modeled as a four-state stochastic dynamic program.The discrete state-action values are derived recursively via the principle of optimality.Real-time dispatch actions are generated by using the action-value tabular leveraging inexact ultra-short-term forecasts.Numerical tests over one year demonstrate that the proposed method successfully fulfills reliable operation on 355 days and achieve an optimality gap of 9.47%compared with the ex-post optimum,which is comparable to model predictive control using exact 2–3-hour-ahead wind power forecasts.
文摘Research on high-speed railways is a relatively new yet highly significant field in Vietnam.Among its key components,train control signaling plays a critical role,as it directly affects various interconnected systems,including infrastructure,traction power supply,operational planning,and overall railway safety.This article focuses on evaluating the capacity of the line based on the types of signals suitable for high-speed railways that have been effectively implemented in several European countries and successfully adapted in China.The research and simulation are conducted using MATLAB software,a reliable and widely adopted tool in the scientific community.The findings demonstrate that under normal conditions,the European Railway Traffic Management System/European Train Control System(ERTMS/ETCS)Level 2 signaling can support up to 23.7485 trains/hour/direction.Meanwhile,ERTMS/ETCS Level 3 with full moving block can accommodate up to 30.8735 trains/hour/direction,and ERTMS/ETCS Level 3 with fixed virtual blocks up to 29.4694 trains/hour/direction.In emergency scenarios,ERTMS/ETCS Level 3 with full moving block reduces headway by 33.27%compared to CTCS Level 3,while ERTMS/ETCS Level 3 with fixed virtual blocks achieves a 28.78%reduction.Overall,the ERTMS/ETCS Level 3 emerges as a state-of-the-art signaling technology offering high capacity and operational efficiency,and is recommended as a forward-looking solution for future implementation in Vietnam.
基金funded by the Science and Technology Research and Development Program Project of China Railway Group Co.,Ltd,grant number P2024X002the China Academy of Railway Sciences Corporation Limited,grant number 2024YJ154.
文摘Purpose-This study investigates the impact of flagship trains on high-speed railway capacity utilization and develops a brand value-oriented optimization framework that balances service quality enhancement with operational efficiency.Design/methodology/approach-A mathematical optimization model based on integer programming is developed,incorporating flagship train constraints into capacity optimization.Case studies compare scenarios with and without flagship train considerations using the Beijing-Shanghai High-Speed Railway data across 20 experimental groups.Findings-Operating flagship trains with hourly departure constraints results in an average decrease of 0.9 trains and an 8.4%reduction in capacity utilization rate.When scheduling 2 flagship trains within a 2-h timeframe,capacity utilization decreases from 86.43%to 83.73%,quantifying the trade-off between brand positioning and operational capacity.Originality/value-This research provides the first quantitative framework for brand value-oriented railway capacity optimization,establishing clear definitions for flagship trains and mathematical foundations for evaluating service quality versus efficiency trade-offs.The findings offer practical decision support for railway operators balancing competitive positioning with capacity maximization.
基金supported by the National Key R&D Program of China(2022YFD1301800)grants from the National Natural Science Foundation of China(grant number 32502899)+1 种基金China Agriculture Research System of MOF and MARA(CARS-42-10)the Agricultural Science and Technology Innovation Program of CAAS(CAAS-ASTIP-2023-IFR-13)。
文摘Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particularly those associated with antioxidant defense,intestinal development and host-microbiota interactions.Method A total of 1001-day-old Pekin ducklings were used in this study with 50 DHAV-3 susceptible and resistant ducks,respectively.Samples were collected at 7 days post-hatching(D7),D21 and D42,10 birds per group.We compared DHAV-3 resistant and susceptible ducks during early development with respect to immune organ indices,antioxidant capacity,intestinal morphology,barrier-related gene expression and cecal microbiota.Result Resistant ducks exhibited higher spleen indices and stronger antioxidant capacity,characterized by increased superoxide dismutase,reduced glutathione,and total antioxidant capacity,along with lower malondialdehyde levels at D7 and D21.In contrast,susceptible ducks showed compensatory thymus hypertrophy and delayed development of antioxidant defense and intestinal maturation.Ileal morphology revealed greater villus height and width with more regular arrangement in resistant ducks at D7,whereas these differences diminished at D21 and D42.Gene expression analysis demonstrated higher early expression of the tight junction proteins CLDN1 and CLDN3 in resistant ducks,while susceptible ducks displayed elevated MUC2 and OCLN,suggesting stress induced compensatory responses.Cecal microbiota analysis revealed distinct colonization patterns in early development.Resistant ducks were enriched with Firmicutes and beneficial genera such as Enterococcus and Lactobacillus,whereas susceptible ducks harbored higher abundances of Bacteroidota and potentially opportunistic taxa.Microbial diversity increased with age in both groups,but resistant ducks displayed more orderly succession and enrichment of SCFA producing genera,including Subdoligranulum and Phascolarctobacterium,which positively correlated with plasma antioxidant indices.Conclusion DHAV-3 resistant ducks exhibit early advantages in antioxidant defense,intestinal barrier development and colonization by beneficial microbiota,which collectively contribute to enhanced disease resistance.These findings highlight the synergistic roles of host physiology and gut microbiota in shaping resistance.In the future,integrating genomic selection with microbiota modulation and antioxidant interventions may accelerate the breeding of highly resistant duck lines and provide scientific evidence and practical strategies for controlling duck viral hepatitis.
文摘China Standardization:Can you please briefly introduce ISO,its international standards as well as your scope of work?Rachel Miller Prada:ISO is an independent non-governmental organization dedicated to developing international standards.Currently,ISO has 175 member bodies,representing 175 countries that participate in its standard development work.We have a portfolio of over 24,000 international standards,with around 100 new standards issued or existing ones revised every month.The ultimate goal of our standardization work is to support the achievement of the United Nations Sustainable Development Goals(SDGs).Every standard we develop and every task I undertake in my role contributes to these global objectives.
文摘In this paper,we propose a novel probabilistic method for predicting the undrained bearing capacity of spatially variable soils.Our approach combines a Gaussian process regression(GPR)-based surrogate model with random cell-based smoothed finite analysis.The Gaussian process emulator(GPE)serves as a statistical tool for making predictions from a data set.First,we validate the accuracy and efficiency of kinematic limit analysis using the cell-based smoothed finite element method(CS-FEM)against the standard finite element method(FEM)and edge-based smoothed FEM(ES-FEM).The numerical results demonstrate that the CS-FEM framework surpasses traditional numerical approaches,establishing its reliability in computing collapse loads.Subsequently,we conduct several hundred simulations to develop a surrogate model for predicting the undrained bearing capacity of shallow foundations.By utilizing various kernel functions,we enhance the accuracy of the GPE in these predictions.This method offers a practical and efficient solution,effectively addressing multiple uncertainties.Numerical results indicate that the GPE significantly boosts computational efficiency,achieving satisfactory outcomes within minutes compared to the days required for conventional simulations.Notably,the mean absolute percentage error(MAPE)decreases from 2.38%to 1.82%for rough foundations when employing Matérn and rational quadratic kernel functions,respectively.Additionally,combining different kernel functions further enhances the accuracy of collapse load predictions.
基金funded by Science and Technology Projects from State Grid Corporation of China,(Research on Adaptive Balance Optimization and Simulation Technology of Industrial community Energy System with High Proportion of Distributed Energy,No.:5100-202355752A-3-4-SY).
文摘To achieve the goals of sustainable development of the energy system and the construction of a lowcarbon society,this study proposes a multi-energy storage collaborative optimization strategy for industrial park that integrates the laddered carbon trading mechanism with demand response.Firstly,a dual dimensional DR model is constructed based on the characteristics of load elasticity.The alternativeDRenables flexible substitution of energy loads through complementary conversion of electricity/heat/cold multi-energy sources,while the price DR relies on timeof-use electricity price signals to guide load spatiotemporal migration;Secondly,the LCT mechanism is introduced to achieve optimal carbon emission costs through a tiered carbon quota allocation mechanism.On this basis,an optimization decision model is established with the core objective of maximizing the annual net profit of the park.The objective function takes into account energy sales revenue,generator unit costs,and investment and operation costs of multiple types of energy storage facilities.Themodel constraint system covers three key dimensions:dynamic operation constraints of power generation units,including unit output limits,ramping capability,and minimum start-stop time;the physical boundary of an electric/hot/cold multi-energy storage system involves energy storage capacity and charge/discharge efficiency;The multi-energy network coupling balance equation ensures that the energy conversion and transmission process satisfies the law of conservation of energy.Using CPLEX mathematical programming solver for simulation verification,construct an energy storage capacity configuration decision process that includes LCT-DR synergistic effect.The research results show that compared with the traditional single energy storage configuration mode,this strategy effectively enhances the economic feasibility and engineering practicality of industrial park operation by coordinating demand side resource scheduling and finely controlling carbon costs,while maintaining stable system operation.Its methodological framework provides a technical path that combines theoretical rigor and practical operability for the low-carbon transformation of regional integrated energy systems.
基金supported by the Chinese Research Academy of Envi-ronmental Sciences(No.2024YSKY-57)the National Key Research and Development Program of China(No.2017YFC0212501)Xinjiang Uygur Autonomous Region Environmental Monitoring Central Station(No.HYZB-2022-0320).
文摘Atmospheric oxidation capacity(AOC)refers to the oxidation capacity of atmospheric chemical processes for major pollutants.A comprehensive observation campaign was conducted on a typical PM_(2.5)pollution event in Urumqi,Northwest China,from January 15 to February 15,2024.Four typical cases representing PM_(2.5)levels from non-polluted to heavily polluted periods were selected to estimate AOC,OH reactivity,their relationship with secondary components,and the HO_(x)budget in PM_(2.5)using the Framework for 0-D Atmospheric Modeling model.Aromatics and alkanes contributed 54%-79%and 18%-46%of secondary organic aerosols(SOA)formation,respectively.The sulfur oxidation ratio(SOR)and nitrogen oxidation ratio(NOR)increased with rising PM_(2.5)levels.As AOC increased,SOR showed the same trend,while NOR and SOA decreased slightly,and ammonia oxidation ratio values remained almost unchanged.OH radicals were the primary oxidants during the daytime,whereas NO_(3)played a dominant role at nighttime.CO(24%-51%),NO2(27%-34%),and alkenes(7%-12%)were the dominant contributors to OH reactivity.The HO_(2)+NO reaction pathway contributes 67%-84%to the production of OH,while Others(including carbonyl compounds photolysis,the permutation reactions of RO2,etc.),RO_(2)+NO and OH+CO reaction pathways were the main pathways for HO2 production.A comprehensive understanding of the interactions among AOC,SOA,and radical cycling is crucial for formulating effective air quality management strategies aimed at mitigating secondary pollution under diverse atmospheric conditions.
基金2024 Medical Science Research Project Plan of Hebei Province:Research on the Rehabilitation Effect of Combined Exercise Intervention Based on a Hospital-Community-Family Model for Elderly Patients with Chronic Diseases(Project No.:20240083)Youth Science and Technology Project of the Hebei Provincial Health Department:Research on the Standardization Level of Self-Management in Patients with Diabetic Foot and Related Factors Affecting Wound Healing(Project No.:20190002)。
文摘Objective:To explore the application effect of combined exercise intervention based on the hospital-community-family model on intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney disease.Methods:Using convenience sampling,100 elderly patients with diabetes mellitus complicated by chronic kidney disease who received treatment in the endocrinology department of a tertiary A-level hospital from May 2024 to May 2025 were selected as the study subjects.They were randomly divided into an experimental group(50 cases)and a control group(50 cases)using a random number table method.The control group received routine health education and telephone follow-up,while the experimental group,in addition to the control group’s interventions,underwent combined exercise intervention based on the hospital-community-family model.Remote medical guidance was utilized to monitor and study the application effect of exercise intervention on intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney disease.Fasting blood glucose,2-hour postprandial blood glucose,glomerular filtration rate,6-minute walk distance,and scores in five dimensions of intrinsic capacity(exercise,cognition,psychology,vitality,and sensation)were measured before the intervention,at 4 weeks of intervention,and at 12 weeks of intervention for both groups.Results:Before the exercise intervention,there were no statistically significant differences(p>0.05)between the two groups in terms of fasting blood glucose,2-hour postprandial blood glucose,glomerular filtration rate,6-minute walk distance,and scores across five dimensions of intrinsic capacity:mobility,cognition,psychology,vitality,and sensation.After 12 weeks of intervention,the experimental group demonstrated significantly higher scores than the control group in glomerular filtration rate,6-minute walk distance,and the dimensions of mobility,cognition,and vitality within intrinsic capacity,with all differences being statistically significant(p<0.05).Conversely,the experimental group showed significantly lower scores than the control group in fasting blood glucose,2-hour postprandial blood glucose,and the psychological dimension of intrinsic capacity,with these differences also being statistically significant(p<0.05).Conclusion:Continuous nursing care utilizing telemedicine based on a hospital-community-family model combined with exercise intervention can effectively enhance exercise tolerance and intrinsic capacity in elderly patients with diabetes mellitus complicated by chronic kidney disease,thereby improving their quality of life.The effectiveness of the intervention is positively correlated with the duration of the intervention.
