This paper firstly analyzed the operation model,market positioning,market demand forecast as well as market competition and challenges,park site selection,and transportation conditions for construction of the Cold-Cha...This paper firstly analyzed the operation model,market positioning,market demand forecast as well as market competition and challenges,park site selection,and transportation conditions for construction of the Cold-Chain Logistics Park of Agricultural Products in Sanshui.Then,it presented the overall planning scheme for construction of the Cold-Chain Logistics Park of Agricultural Products from a progressive two-stage perspective of overall planning and stage-by-stage implementation.The first stage mainly performs the function as a transaction platform of agricultural products and meanwhile provides customers with agricultural products storage and inspection services.The second stage adds value-added services such as distribution processing,modified atmosphere storage,freezing and refrigeration,market price information distribution,E-commerce of agricultural products and personalized services.It is expected to provide references and suggestions for the construction of the Cold-Chain Logistics Park of Agricultural Products.展开更多
This paper mainly studies the problem of multi-task assignment of providers in port logistics service supply chain.As a core enterprise,port plays the role of logistics service integrator.With the continuous developme...This paper mainly studies the problem of multi-task assignment of providers in port logistics service supply chain.As a core enterprise,port plays the role of logistics service integrator.With the continuous development of industrial integration,logistics service providers not only provide one kind of logistics service,but also develop into composite suppliers who capable of providing a variety of logistics services.This paper studies the task assignment problem of multi-service capability providers in the port logistics service supply chain.The two-stage logistics service provider task assignment model was built,which is based on the mixed evaluation method(including MOORA and FMEA)and the multi-objective planning method.Eventually,the effectiveness of the model method was verified by combining with an example.展开更多
A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary ...A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary micro-variables evolution at different temperatures and their interaction.The dislocation density was incorporated into the model to capture the effect of creep deformation on precipitation.Quantitative transmission electron microscopy and experimental data obtained from a previous study were used to calibrate the model.Subsequently,the developed constitutive model was implemented in the finite element(FE)software ABAQUS via the user subroutines for TSCA process simulation and the springback prediction of an integral panel.A TSCA test was performed.The result shows that the maximum radius deviation between the formed plate and the simulation results is less than 0.4 mm,thus validating the effectiveness of the developed constitutive model and FE model.展开更多
In the era of green logistics,digital transformation has become an effective means for the logistics industry’s high-quality development.Using listed companies in China’s logistics industry from 2010 to 2021 as the ...In the era of green logistics,digital transformation has become an effective means for the logistics industry’s high-quality development.Using listed companies in China’s logistics industry from 2010 to 2021 as the research samples,this paper conducts an empirical test on the impact of the digital transformation of logistics enterprises on their green in-novation.Specifically,enterprise digital transformation indicators are constructed through the text analysis method,and the fixed-effects model is applied for analysis.The results indicate that the digital transformation of logistics enterprises has a significant promoting effect on their green innovation;the promoting effect of the digital transformation of logistics enterprises on green innovation is primarily achieved by easing corporate financing constraints and reducing corporate en-vironmental uncertainty;and the impact of digital transformation on green innovation is geographically heterogeneous.展开更多
Lexical analysis is a fundamental task in natural language processing,which involves several subtasks,such as word segmentation(WS),part-of-speech(POS)tagging,and named entity recognition(NER).Recent works have shown ...Lexical analysis is a fundamental task in natural language processing,which involves several subtasks,such as word segmentation(WS),part-of-speech(POS)tagging,and named entity recognition(NER).Recent works have shown that taking advantage of relatedness between these subtasks can be beneficial.This paper proposes a unified neural framework to address these subtasks simultaneously.Apart from the sequence tagging paradigm,the proposed method tackles the multitask lexical analysis via two-stage sequence span classification.Firstly,the model detects the word and named entity boundaries by multilabel classification over character spans in a sentence.Then,the authors assign POS labels and entity labels for words and named entities by multi-class classification,respectively.Furthermore,a Gated Task Transformation(GTT)is proposed to encourage the model to share valuable features between tasks.The performance of the proposed model was evaluated on Chinese and Thai public datasets,demonstrating state-of-the-art results.展开更多
Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mec...Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.展开更多
Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for manag...Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for managing the supply chain of these commodities. This study aimed to evaluate the effectiveness of LMIS in ensuring the availability of essential medicines and medical supplies in public hospitals in the Copperbelt Province of Zambia. Materials and Methods: From February to April 2022, a cross-sectional study was conducted in 12 public hospitals across the Copperbelt Province. Data were collected using structured questionnaires, checklists, and stock control cards. The study assessed LMIS availability, training, and knowledge among pharmacy personnel, as well as data accuracy, product availability, and order fill rates. Descriptive statistics were used to analyse the data. Results: All surveyed hospitals had LMIS implemented and were using eLMIS as the primary LMIS. Only 47% and 48% of pharmacy personnel received training in eLMIS and Essential Medicines Logistics Improvement Program (EMLIP), respectively. Most personnel demonstrated good knowledge of LMIS, with 77.7% able to log in to eLMIS Facility Edition, 76.6% able to locate stock control cards in the system, and 78.7% able to perform transactions. However, data accuracy from physical and electronic records varied from 0% to 60%, and product availability ranged from 50% to 80%. Order fill rates from Zambia Medicines and Medical Supplies Agency (ZAMMSA) were consistently below 30%. Discrepancies were observed between physical stock counts and eLMIS records. Conclusion: This study found that most hospitals in the Copperbelt Province of Zambia have implemented LMIS use. While LMIS implementation is high in the Copperbelt Province of Zambia, challenges such as low training levels, data inaccuracies, low product availability, and order fill rates persist. Addressing these issues requires a comprehensive approach, including capacity building, data quality improvement, supply chain coordination, and investment in infrastructure and human resources. Strengthening LMIS effectiveness is crucial for improving healthcare delivery and patient outcomes in Zambia.展开更多
Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving fac...Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving factors at both the generation and treatment stages of SO_(2),more effective targeted mitigation strategies can be developed.We employ the Tapio decoupling model and propose a two-stage method to examine the decoupling issues related to SO_(2).Our findings indicate that:①DEI shows a steady and significant improvement,with SO_(2)emission intensity identified as the primary driver.②for the decoupling of economic growth and SO_(2)generation,energy scale serves as the largest stimulator,while the effect of energy intensity changes from negative to positive,and pollution intensity is first positive and then negative.③For the decoupling of SO_(2)generation and SO_(2)removal,treatment efficiency leads as the largest promoter,followed by treatment intensity.Based on these results,this study recommends that China focuses more on enhancing clean energy utilization and the effectiveness of treatment processes.展开更多
BACKGROUND Two-stage revision is the most common treatment for chronic periprosthetic joint infection of the hip,involving a resection arthroplasty with or without placement of an antibiotic-loaded spacer,followed by ...BACKGROUND Two-stage revision is the most common treatment for chronic periprosthetic joint infection of the hip,involving a resection arthroplasty with or without placement of an antibiotic-loaded spacer,followed by antibiotic therapy before reimplantation.AIM To compare the outcomes and complications of two consecutive treatment protocols for two-stage revision arthroplasty of the infected hip:One using Girdlestone with an antibiotic holiday,the other using custom-made articulating spacers(CUMARS)without an antibiotic holiday.METHODS In this retrospective study,two consecutive cohorts were compared.Group A(2017-2020)underwent two-stage revision with a Girdlestone and an antibiotic holiday before reimplantation,while Group B(2020-2023)received CUMARS whenever possible,and no antibiotic holiday,or a Girdlestone if indicated.The primary outcome was successful infection eradication after one year.Secondary outcomes included surgical duration,length of hospital stay,weight-bearing allowance,discharge destination,and complications.RESULTS A total of 98 patients were included:39 patients in Group A and 59 patients in Group B.Successful infection eradication after one year was achieved in 69%of Group A and 83%of Group B(P=0.164).Patients in Group B were more frequently allowed to bear weight(64%vs 18%,P<0.001),had a shorter in-hospital stay(9 vs 16 days,P<0.001),and were more often discharged home after the first surgery(48%vs 24%,P=0.048).No significant differences were found in(mechanical)complications.CONCLUSION A protocol including CUMARS is a safe and effective treatment,offering faster recovery,shorter length of hospital stay,and enabling more patients to return home during the interval.This reduces strain on patients and the healthcare system,potentially saving costs,without compromising infection control or increasing(mechanical)complications.展开更多
Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growin...Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growing observation demands.The observation Scheduling Problem in the MEOS constellation(MEOSSP)is a challenging issue due to the large number of satellites and tasks,as well as complex observation constraints.To address the large-scale and complicated MEOSSP,we develop a Two-Stage Scheduling Algorithm based on the Pointer Network with Attention mechanism(TSSA-PNA).In TSSA-PNA,the MEOS observation scheduling is decomposed into a task allocation stage and a single-MEOS scheduling stage.In the task allocation stage,an adaptive task allocation algorithm with four problem-specific allocation operators is proposed to reallocate the unscheduled tasks to new MEOSs.Regarding the single-MEOS scheduling stage,we design a pointer network based on the encoder-decoder architecture to learn the optimal singleMEOS scheduling solution and introduce the attention mechanism into the encoder to improve the learning efficiency.The Pointer Network with Attention mechanism(PNA)can generate the single-MEOS scheduling solution quickly in an end-to-end manner.These two decomposed stages are performed iteratively to search for the solution with high profit.A greedy local search algorithm is developed to improve the profits further.The performance of the PNA and TSSA-PNA on singleMEOS and multi-MEOS scheduling problems are evaluated in the experiments.The experimental results demonstrate that PNA can obtain the approximate solution for the single-MEOS scheduling problem in a short time.Besides,the TSSA-PNA can achieve higher observation profits than the existing scheduling algorithms within the acceptable computational time for the large-scale MEOS scheduling problem.展开更多
The development of efficient and clean heating technologies is crucial for reducing carbon emissions in regions with severe cold regions.This research designs a novel two-stage phase change heat storage coupled solar-...The development of efficient and clean heating technologies is crucial for reducing carbon emissions in regions with severe cold regions.This research designs a novel two-stage phase change heat storage coupled solar-air source heat pump heating system structure that is specifically designed for such regions.The two-stage heat storage device in this heating system expands the storage temperature range of solar heat.The utilization of the two-stage heat storage device not onlymakes up for the instability of the solar heating system,but can also directlymeet the building heating temperature,and can reduce the influence of low-temperature outdoor environments in severe cold regions on the heating performance of the air source heat pump by using solar energy.Therefore,the two-stage phase change heat storage coupled to the solar energy-air source heat pump heating system effectively improves the utilization rate of solar energy.A numerical model of the system components and their integration was developed using TRNSYS software in this study,and various performance aspects of the system were simulated and analyzed.The simulation results demonstrated that the two-stage heat storage device can effectively store solar energy,enabling its hierarchical utilization.The low-temperature solar energy stored by the two-stage phase change heat storage device enhances the coefficient of performance of the air source heat pump by 11.1%in severe cold conditions.Using the Hooke-Jeeves optimization method,the annual cost and carbon emissions are taken as optimization objectives,with the optimized solar heat supply accounting for 52.5%.This study offers valuable insights into operational strategies and site selection for engineering applications,providing a solid theoretical foundation for the widespread implementation of this system in severe cold regions.展开更多
Integrated-energy systems(IESs)are key to advancing renewable-energy utilization and addressing environmental challenges.Key components of IESs include low-carbon,economic dispatch and demand response,for maximizing r...Integrated-energy systems(IESs)are key to advancing renewable-energy utilization and addressing environmental challenges.Key components of IESs include low-carbon,economic dispatch and demand response,for maximizing renewable-energy consumption and supporting sustainable-energy systems.User participation is central to demand response;however,many users are not inclined to engage actively;therefore,the full potential of demand response remains unrealized.User satisfaction must be prioritized in demand-response assessments.This study proposed a two-stage,capacity-optimization configuration method for user-level energy systems con-sidering thermal inertia and user satisfaction.This method addresses load coordination and complementary issues within the IES and seeks to minimize the annual,total cost for determining equipment capacity configurations while introducing models for system thermal inertia and user satisfaction.Indoor heating is adjusted,for optimizing device output and load profiles,with a focus on typical,daily,economic,and environmental objectives.The studyfindings indicate that the system thermal inertia optimizes energy-system scheduling considering user satisfaction.This optimization mitigates environmental concerns and enhances clean-energy integration.展开更多
Logistics service providers significantly contribute to environmental degradation through improper waste disposal,hazardous packaging materials,excessive fuel consumption,and emissions.This study examines the impact o...Logistics service providers significantly contribute to environmental degradation through improper waste disposal,hazardous packaging materials,excessive fuel consumption,and emissions.This study examines the impact of green in-bound logistics and green outbound logistics on environmental,economic,and social performance of logistics companies using survey data from 221 Vietnamese logistics firms.Statistical analysis using Structural Equation Modeling revealed that green inbound logistics positively influences environmental and social performance while moderately affecting eco-nomic outcomes.In contrast,green outbound logistics demonstrates stronger effects on economic and environmental performance but exhibits limited impact on social dimensions.The measurement model showed strong reliability and validity(Cronbach's Alpha>0.70,robust Composite Reliability and Average Variance Extracted values),with excellent fit indices(Chi-Square/df=1.681,GFI=0.898,TLI=0.945,CFI=0.956,RMSEA=0.056).These findings highlight important distinctions between inbound and outbound green logistics impacts,offering valuable insights for an industry with currently low adoption rates of sustainable practices.The research demonstrates that implementing green logistics enhances both environmental preservation and business performance,providing compelling evidence for companies to accelerate their sustainability transition.By understanding these differential impacts,logistics firms can develop more tar-geted and effective sustainability strategies that optimize triple bottom line outcomes.展开更多
Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea o...Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea or river.Network properties including the degree distribution,degree correlations,clustering,shortest path length,centrality and betweenness are studied in different definition of network topology.It is found that geographical constraint plays an important role in the network topology of SCLNC.We also study the traffic flow of SCLNC based on the weighted network representation,and demonstrate the weight distribution can be described by power law or exponential function depending on the assumed definition of network topology.Other features related to SCLNC are also investigated.展开更多
With the accelerated expansion of the platform economy,the supply chain has evolved into a new stage of the platform supply chain(PSC),which is deeply integrated with the platform economy.Logistics engineering managem...With the accelerated expansion of the platform economy,the supply chain has evolved into a new stage of the platform supply chain(PSC),which is deeply integrated with the platform economy.Logistics engineering management plays a crucial role in ensuring the efficient operation of PSCs and contributes to the construction of a global economic system.Given its importance to the efficiency of PSCs,the choice of logistics service strategy in logistics engineering management has attracted considerable scholarly attention.However,the current research is fragmented and lacks systematic analysis and synthesis.This paper provides a comprehensive overview of logistics engineering management in PSCs from the perspective of logistics service strategy selection from January 2005 to September 2024.To this end,we first review the research related to self-built logistics(SBL)and third-party logistics(3PL)in PSCs due to the complete independence of these two logistics service strategies.The results show that the following two topics are of great interest to researchers.One is the choice of the optimal logistics service strategy for the members of PSCs,while the other is the impact of factors related to logistics services on PSCs,including the channel selection,platform entry,sales model,and so forth.Next,we summarize the determinants influencing the choice between SBL and 3PL for the members of PSCs.The results indicate that the influencing factors are the service cost and service level,followed by the channel,brand,market potential,and competition.Then,on the basis of the themes of logistics service sharing(LSS),we review the research on LSS in PSCs,as LSS often emerges as an innovative model after a certain stage of development in SBL and 3PL.We find that LSS is regarded as an important complement to SBL and 3PL,with key research hotspots,including the channel,partner selection,and service competition.Service cost is a major factor influencing LSS,with competition,consumers'logistics preference,and market potential being secondary factors.Finally,this paper outlines several important and promising directions for future research.This paper has important management implications for building a modern logistics system and promoting the transformation of PSCs.展开更多
As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions an...As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions and navigational circumstances.There-fore,this paper aims at establishing a two-stage optimization framework for hybrid energy ship power system.The proposed framework considers multiple optimizations of route,speed planning,and energy management under the constraints of sea conditions during navigation.First,a complex hybrid ship power model consisting of diesel generation system,propulsion system,energy storage system,photovoltaic power generation system,and electric boiler system is established,where sea state information and ship resistance model are considered.With objective optimization functions of cost and greenhouse gas(GHG)emissions,a two-stage optimization framework consisting of route planning,speed scheduling,and energy management is constructed.Wherein the improved A-star algorithm and grey wolf optimization algorithm are introduced to obtain the optimal solutions for route,speed,and energy optimization scheduling.Finally,simulation cases are employed to verify that the proposed two-stage optimization scheduling model can reduce load energy consumption,operating costs,and carbon emissions by 17.8%,17.39%,and 13.04%,respectively,compared with the non-optimal control group.展开更多
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy...In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.展开更多
In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integra...In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.展开更多
文摘This paper firstly analyzed the operation model,market positioning,market demand forecast as well as market competition and challenges,park site selection,and transportation conditions for construction of the Cold-Chain Logistics Park of Agricultural Products in Sanshui.Then,it presented the overall planning scheme for construction of the Cold-Chain Logistics Park of Agricultural Products from a progressive two-stage perspective of overall planning and stage-by-stage implementation.The first stage mainly performs the function as a transaction platform of agricultural products and meanwhile provides customers with agricultural products storage and inspection services.The second stage adds value-added services such as distribution processing,modified atmosphere storage,freezing and refrigeration,market price information distribution,E-commerce of agricultural products and personalized services.It is expected to provide references and suggestions for the construction of the Cold-Chain Logistics Park of Agricultural Products.
文摘This paper mainly studies the problem of multi-task assignment of providers in port logistics service supply chain.As a core enterprise,port plays the role of logistics service integrator.With the continuous development of industrial integration,logistics service providers not only provide one kind of logistics service,but also develop into composite suppliers who capable of providing a variety of logistics services.This paper studies the task assignment problem of multi-service capability providers in the port logistics service supply chain.The two-stage logistics service provider task assignment model was built,which is based on the mixed evaluation method(including MOORA and FMEA)and the multi-objective planning method.Eventually,the effectiveness of the model method was verified by combining with an example.
基金supported by the National Key R&D Program of China(No.2021YFB3400900)the National Natural Science Foundation of China(Nos.52175373,52205435)+1 种基金Natural Science Foundation of Hunan Province,China(No.2022JJ40621)the Innovation Fund of National Commercial Aircraft Manufacturing Engineering Technology Center,China(No.COMACSFGS-2022-1875)。
文摘A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary micro-variables evolution at different temperatures and their interaction.The dislocation density was incorporated into the model to capture the effect of creep deformation on precipitation.Quantitative transmission electron microscopy and experimental data obtained from a previous study were used to calibrate the model.Subsequently,the developed constitutive model was implemented in the finite element(FE)software ABAQUS via the user subroutines for TSCA process simulation and the springback prediction of an integral panel.A TSCA test was performed.The result shows that the maximum radius deviation between the formed plate and the simulation results is less than 0.4 mm,thus validating the effectiveness of the developed constitutive model and FE model.
基金supported by the National Natural Science Foundation of China(72374061,72204243)the Ministry of Education’s Humanities and Social Science Research Youth Fund Project(20YJC630138,22YJC630056)+1 种基金Anhui Provincial Natural Science Foundation(2208085UD02)New Liberal Arts Fund Expansion Project of University of Science and Technology of China(FSSF-A-230317).
文摘In the era of green logistics,digital transformation has become an effective means for the logistics industry’s high-quality development.Using listed companies in China’s logistics industry from 2010 to 2021 as the research samples,this paper conducts an empirical test on the impact of the digital transformation of logistics enterprises on their green in-novation.Specifically,enterprise digital transformation indicators are constructed through the text analysis method,and the fixed-effects model is applied for analysis.The results indicate that the digital transformation of logistics enterprises has a significant promoting effect on their green innovation;the promoting effect of the digital transformation of logistics enterprises on green innovation is primarily achieved by easing corporate financing constraints and reducing corporate en-vironmental uncertainty;and the impact of digital transformation on green innovation is geographically heterogeneous.
基金supported by National Natural Science Foundation of China(Grant No.62266028,62266027,U21B2027,and U24A20334)Major Science and Technology Programs in Yunnan Province(Grant No.202302AD080003,202402AG050007,and 202303AP140008)+1 种基金Yunnan Province Basic Research Program(Grant No.202301AS070047,202301AT070471,and 202401BC070021)Kunming University of Science and Technology's"Double First-rate"construction joint project(Grant No.202201BE070001-021).
文摘Lexical analysis is a fundamental task in natural language processing,which involves several subtasks,such as word segmentation(WS),part-of-speech(POS)tagging,and named entity recognition(NER).Recent works have shown that taking advantage of relatedness between these subtasks can be beneficial.This paper proposes a unified neural framework to address these subtasks simultaneously.Apart from the sequence tagging paradigm,the proposed method tackles the multitask lexical analysis via two-stage sequence span classification.Firstly,the model detects the word and named entity boundaries by multilabel classification over character spans in a sentence.Then,the authors assign POS labels and entity labels for words and named entities by multi-class classification,respectively.Furthermore,a Gated Task Transformation(GTT)is proposed to encourage the model to share valuable features between tasks.The performance of the proposed model was evaluated on Chinese and Thai public datasets,demonstrating state-of-the-art results.
基金Project(52274348)supported by the National Natural Science Foundation of ChinaProject(2022JH1/10400024)supported by the Major Projects for the“Revealed Top”Science and Technology of Liaoning Province,China。
文摘Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.
文摘Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for managing the supply chain of these commodities. This study aimed to evaluate the effectiveness of LMIS in ensuring the availability of essential medicines and medical supplies in public hospitals in the Copperbelt Province of Zambia. Materials and Methods: From February to April 2022, a cross-sectional study was conducted in 12 public hospitals across the Copperbelt Province. Data were collected using structured questionnaires, checklists, and stock control cards. The study assessed LMIS availability, training, and knowledge among pharmacy personnel, as well as data accuracy, product availability, and order fill rates. Descriptive statistics were used to analyse the data. Results: All surveyed hospitals had LMIS implemented and were using eLMIS as the primary LMIS. Only 47% and 48% of pharmacy personnel received training in eLMIS and Essential Medicines Logistics Improvement Program (EMLIP), respectively. Most personnel demonstrated good knowledge of LMIS, with 77.7% able to log in to eLMIS Facility Edition, 76.6% able to locate stock control cards in the system, and 78.7% able to perform transactions. However, data accuracy from physical and electronic records varied from 0% to 60%, and product availability ranged from 50% to 80%. Order fill rates from Zambia Medicines and Medical Supplies Agency (ZAMMSA) were consistently below 30%. Discrepancies were observed between physical stock counts and eLMIS records. Conclusion: This study found that most hospitals in the Copperbelt Province of Zambia have implemented LMIS use. While LMIS implementation is high in the Copperbelt Province of Zambia, challenges such as low training levels, data inaccuracies, low product availability, and order fill rates persist. Addressing these issues requires a comprehensive approach, including capacity building, data quality improvement, supply chain coordination, and investment in infrastructure and human resources. Strengthening LMIS effectiveness is crucial for improving healthcare delivery and patient outcomes in Zambia.
基金the National Natural Science Foundation of China[Grant No.52270183].
文摘Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving factors at both the generation and treatment stages of SO_(2),more effective targeted mitigation strategies can be developed.We employ the Tapio decoupling model and propose a two-stage method to examine the decoupling issues related to SO_(2).Our findings indicate that:①DEI shows a steady and significant improvement,with SO_(2)emission intensity identified as the primary driver.②for the decoupling of economic growth and SO_(2)generation,energy scale serves as the largest stimulator,while the effect of energy intensity changes from negative to positive,and pollution intensity is first positive and then negative.③For the decoupling of SO_(2)generation and SO_(2)removal,treatment efficiency leads as the largest promoter,followed by treatment intensity.Based on these results,this study recommends that China focuses more on enhancing clean energy utilization and the effectiveness of treatment processes.
文摘BACKGROUND Two-stage revision is the most common treatment for chronic periprosthetic joint infection of the hip,involving a resection arthroplasty with or without placement of an antibiotic-loaded spacer,followed by antibiotic therapy before reimplantation.AIM To compare the outcomes and complications of two consecutive treatment protocols for two-stage revision arthroplasty of the infected hip:One using Girdlestone with an antibiotic holiday,the other using custom-made articulating spacers(CUMARS)without an antibiotic holiday.METHODS In this retrospective study,two consecutive cohorts were compared.Group A(2017-2020)underwent two-stage revision with a Girdlestone and an antibiotic holiday before reimplantation,while Group B(2020-2023)received CUMARS whenever possible,and no antibiotic holiday,or a Girdlestone if indicated.The primary outcome was successful infection eradication after one year.Secondary outcomes included surgical duration,length of hospital stay,weight-bearing allowance,discharge destination,and complications.RESULTS A total of 98 patients were included:39 patients in Group A and 59 patients in Group B.Successful infection eradication after one year was achieved in 69%of Group A and 83%of Group B(P=0.164).Patients in Group B were more frequently allowed to bear weight(64%vs 18%,P<0.001),had a shorter in-hospital stay(9 vs 16 days,P<0.001),and were more often discharged home after the first surgery(48%vs 24%,P=0.048).No significant differences were found in(mechanical)complications.CONCLUSION A protocol including CUMARS is a safe and effective treatment,offering faster recovery,shorter length of hospital stay,and enabling more patients to return home during the interval.This reduces strain on patients and the healthcare system,potentially saving costs,without compromising infection control or increasing(mechanical)complications.
基金supported by the National Natural Science Foundation of China(No.62101587)the National Funded Postdoctoral Researcher Program of China(No.GZC20233578)。
文摘Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growing observation demands.The observation Scheduling Problem in the MEOS constellation(MEOSSP)is a challenging issue due to the large number of satellites and tasks,as well as complex observation constraints.To address the large-scale and complicated MEOSSP,we develop a Two-Stage Scheduling Algorithm based on the Pointer Network with Attention mechanism(TSSA-PNA).In TSSA-PNA,the MEOS observation scheduling is decomposed into a task allocation stage and a single-MEOS scheduling stage.In the task allocation stage,an adaptive task allocation algorithm with four problem-specific allocation operators is proposed to reallocate the unscheduled tasks to new MEOSs.Regarding the single-MEOS scheduling stage,we design a pointer network based on the encoder-decoder architecture to learn the optimal singleMEOS scheduling solution and introduce the attention mechanism into the encoder to improve the learning efficiency.The Pointer Network with Attention mechanism(PNA)can generate the single-MEOS scheduling solution quickly in an end-to-end manner.These two decomposed stages are performed iteratively to search for the solution with high profit.A greedy local search algorithm is developed to improve the profits further.The performance of the PNA and TSSA-PNA on singleMEOS and multi-MEOS scheduling problems are evaluated in the experiments.The experimental results demonstrate that PNA can obtain the approximate solution for the single-MEOS scheduling problem in a short time.Besides,the TSSA-PNA can achieve higher observation profits than the existing scheduling algorithms within the acceptable computational time for the large-scale MEOS scheduling problem.
基金This work was supported by the project of the Research on Energy Consumption of Office Space in Colleges and Universities under the“Dual Carbon Target”(No.CJ202301006).
文摘The development of efficient and clean heating technologies is crucial for reducing carbon emissions in regions with severe cold regions.This research designs a novel two-stage phase change heat storage coupled solar-air source heat pump heating system structure that is specifically designed for such regions.The two-stage heat storage device in this heating system expands the storage temperature range of solar heat.The utilization of the two-stage heat storage device not onlymakes up for the instability of the solar heating system,but can also directlymeet the building heating temperature,and can reduce the influence of low-temperature outdoor environments in severe cold regions on the heating performance of the air source heat pump by using solar energy.Therefore,the two-stage phase change heat storage coupled to the solar energy-air source heat pump heating system effectively improves the utilization rate of solar energy.A numerical model of the system components and their integration was developed using TRNSYS software in this study,and various performance aspects of the system were simulated and analyzed.The simulation results demonstrated that the two-stage heat storage device can effectively store solar energy,enabling its hierarchical utilization.The low-temperature solar energy stored by the two-stage phase change heat storage device enhances the coefficient of performance of the air source heat pump by 11.1%in severe cold conditions.Using the Hooke-Jeeves optimization method,the annual cost and carbon emissions are taken as optimization objectives,with the optimized solar heat supply accounting for 52.5%.This study offers valuable insights into operational strategies and site selection for engineering applications,providing a solid theoretical foundation for the widespread implementation of this system in severe cold regions.
基金supported by the science and technology foundation of Guizhou province[2022]general 013the science and technology foundation of Guizhou province[2022]general 014+1 种基金the science and technology foundation of Guizhou province GCC[2022]016-1the educational technology foundation of Guizhou province[2022]043.
文摘Integrated-energy systems(IESs)are key to advancing renewable-energy utilization and addressing environmental challenges.Key components of IESs include low-carbon,economic dispatch and demand response,for maximizing renewable-energy consumption and supporting sustainable-energy systems.User participation is central to demand response;however,many users are not inclined to engage actively;therefore,the full potential of demand response remains unrealized.User satisfaction must be prioritized in demand-response assessments.This study proposed a two-stage,capacity-optimization configuration method for user-level energy systems con-sidering thermal inertia and user satisfaction.This method addresses load coordination and complementary issues within the IES and seeks to minimize the annual,total cost for determining equipment capacity configurations while introducing models for system thermal inertia and user satisfaction.Indoor heating is adjusted,for optimizing device output and load profiles,with a focus on typical,daily,economic,and environmental objectives.The studyfindings indicate that the system thermal inertia optimizes energy-system scheduling considering user satisfaction.This optimization mitigates environmental concerns and enhances clean-energy integration.
文摘Logistics service providers significantly contribute to environmental degradation through improper waste disposal,hazardous packaging materials,excessive fuel consumption,and emissions.This study examines the impact of green in-bound logistics and green outbound logistics on environmental,economic,and social performance of logistics companies using survey data from 221 Vietnamese logistics firms.Statistical analysis using Structural Equation Modeling revealed that green inbound logistics positively influences environmental and social performance while moderately affecting eco-nomic outcomes.In contrast,green outbound logistics demonstrates stronger effects on economic and environmental performance but exhibits limited impact on social dimensions.The measurement model showed strong reliability and validity(Cronbach's Alpha>0.70,robust Composite Reliability and Average Variance Extracted values),with excellent fit indices(Chi-Square/df=1.681,GFI=0.898,TLI=0.945,CFI=0.956,RMSEA=0.056).These findings highlight important distinctions between inbound and outbound green logistics impacts,offering valuable insights for an industry with currently low adoption rates of sustainable practices.The research demonstrates that implementing green logistics enhances both environmental preservation and business performance,providing compelling evidence for companies to accelerate their sustainability transition.By understanding these differential impacts,logistics firms can develop more tar-geted and effective sustainability strategies that optimize triple bottom line outcomes.
基金supported by Youth Foundation for Research of the Waterborne Transportation Institute.
文摘Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea or river.Network properties including the degree distribution,degree correlations,clustering,shortest path length,centrality and betweenness are studied in different definition of network topology.It is found that geographical constraint plays an important role in the network topology of SCLNC.We also study the traffic flow of SCLNC based on the weighted network representation,and demonstrate the weight distribution can be described by power law or exponential function depending on the assumed definition of network topology.Other features related to SCLNC are also investigated.
基金supported by research grant from the National Natural Science Foundation of China(72102171,71931001,U2469202,and W2411066)the Humanities and Social Sciences Youth Foundation,Ministry of Education of the People's Republic of China(21YJC630006)the Graduate Innovative Fund of Wuhan Institute of Technology(CX2023368)。
文摘With the accelerated expansion of the platform economy,the supply chain has evolved into a new stage of the platform supply chain(PSC),which is deeply integrated with the platform economy.Logistics engineering management plays a crucial role in ensuring the efficient operation of PSCs and contributes to the construction of a global economic system.Given its importance to the efficiency of PSCs,the choice of logistics service strategy in logistics engineering management has attracted considerable scholarly attention.However,the current research is fragmented and lacks systematic analysis and synthesis.This paper provides a comprehensive overview of logistics engineering management in PSCs from the perspective of logistics service strategy selection from January 2005 to September 2024.To this end,we first review the research related to self-built logistics(SBL)and third-party logistics(3PL)in PSCs due to the complete independence of these two logistics service strategies.The results show that the following two topics are of great interest to researchers.One is the choice of the optimal logistics service strategy for the members of PSCs,while the other is the impact of factors related to logistics services on PSCs,including the channel selection,platform entry,sales model,and so forth.Next,we summarize the determinants influencing the choice between SBL and 3PL for the members of PSCs.The results indicate that the influencing factors are the service cost and service level,followed by the channel,brand,market potential,and competition.Then,on the basis of the themes of logistics service sharing(LSS),we review the research on LSS in PSCs,as LSS often emerges as an innovative model after a certain stage of development in SBL and 3PL.We find that LSS is regarded as an important complement to SBL and 3PL,with key research hotspots,including the channel,partner selection,and service competition.Service cost is a major factor influencing LSS,with competition,consumers'logistics preference,and market potential being secondary factors.Finally,this paper outlines several important and promising directions for future research.This paper has important management implications for building a modern logistics system and promoting the transformation of PSCs.
基金supported by the National Natural Science Foundation of China under Grant 62473328by the Open Research Fund of Jiangsu Collaborative Innovation Center for Smart Distribution Network,Nanjing Institute of Technology under No.XTCX202203.
文摘As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions and navigational circumstances.There-fore,this paper aims at establishing a two-stage optimization framework for hybrid energy ship power system.The proposed framework considers multiple optimizations of route,speed planning,and energy management under the constraints of sea conditions during navigation.First,a complex hybrid ship power model consisting of diesel generation system,propulsion system,energy storage system,photovoltaic power generation system,and electric boiler system is established,where sea state information and ship resistance model are considered.With objective optimization functions of cost and greenhouse gas(GHG)emissions,a two-stage optimization framework consisting of route planning,speed scheduling,and energy management is constructed.Wherein the improved A-star algorithm and grey wolf optimization algorithm are introduced to obtain the optimal solutions for route,speed,and energy optimization scheduling.Finally,simulation cases are employed to verify that the proposed two-stage optimization scheduling model can reduce load energy consumption,operating costs,and carbon emissions by 17.8%,17.39%,and 13.04%,respectively,compared with the non-optimal control group.
基金Supported by the National Natural Science Foundation of China(12261018)Universities Key Laboratory of Mathematical Modeling and Data Mining in Guizhou Province(2023013)。
文摘In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.
文摘In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.
