Complex bridge structures designed and constructed by humans often necessitate extensive on-site execution,which carries inherent risks.Consequently,a variety of engineering practices are employed to monitor bridge co...Complex bridge structures designed and constructed by humans often necessitate extensive on-site execution,which carries inherent risks.Consequently,a variety of engineering practices are employed to monitor bridge construction.This paper presents a case study of a large-span prestressed concrete(PC)variable-section continuous girder bridge in China,proposing a feedback system for construction monitoring and establishing a finite element(FE)analysis model for the entire bridge.The alignment of the completed bridge adheres to the initial design expectations,with maximum displacement and pre-arch differences from the ideal state measuring 6.39 and 17.7 mm,respectively,which were less than the 20 mm limit required by the specification.Additionally,the stress monitoring showed that the maximum compressive stress was 10.44 MPa,which was 7.5%different from the finite element results,and better predicted the most unfavorable possible location.These results demonstrate that a scientifically rigorous construction monitoring and feedback system can ensure the safety of bridge construction and meet the expected construction standards.The findings presented in this paper provide valuable insights for bridge construction monitoring practices.展开更多
The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of it...The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.展开更多
With the rapid development of globalization and information technology,intellectual property has been one of the key drivers of economic growth,and the construction of intellectual property system has become an import...With the rapid development of globalization and information technology,intellectual property has been one of the key drivers of economic growth,and the construction of intellectual property system has become an important criterion for measuring the quality of business environment.This article is intended to explore the current status of intellectual property system construction in China,the challenges,and its relationship with the business environment,to propose the corresponding countermeasures and suggestions.The study finds that the legal system of intellectual property in China is gradually improving,and judicial and administrative protection are continuously strengthened.However,the challenges still remain such as frequent infringements,rights hard to protect and insufficient international cooperation.These issues not only affect the legitimate rights and interests of innovation entities,but also for the market fairness and the level of the business environment.Therefore,this article proposes that strengthening the perfection of the intellectual property legal system,enhancing intellectual property services and support capabilities,strengthening international cooperation and exchanges,and accelerating the cultivation of composite talents.It aims to provide theoretical references for the construction of intellectual property system and the optimization of the business environment,promote the high-quality development of economy and enhance the global competitiveness of the country.展开更多
Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capa...Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.展开更多
Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the ar...Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.展开更多
Professional and trade skills are required for handling the construction related projects;Construction industries of the present day however lack useful information concerning different practices,patterns and trends i...Professional and trade skills are required for handling the construction related projects;Construction industries of the present day however lack useful information concerning different practices,patterns and trends involved in risk management.Considering this,the present study focuses on the aforementioned variables of risk management by quantitative analysis specifically in the domain of construction industry.This study has used IBM’s SPSS(Statistical Package for Social Sciences)version 25.0 to analyze the results.This study is an initiative to assess the impact of risk management in the construction sector of Jordan.It will assist the construction sector for exploring the limitations with respect to integrate effective risk management.A sense of competition will be developed through a comparison of risk factors of construction projects among the project stakeholders such as contractors should enhance their risk management practices.展开更多
The increasing cost of infrastructure development risks stifling national investment plans.Many projects in Uganda have suffered because of the frequency and magnitude of claims made by parties involved especially the...The increasing cost of infrastructure development risks stifling national investment plans.Many projects in Uganda have suffered because of the frequency and magnitude of claims made by parties involved especially the contractors.As a result,the construction industry is plagued with claims which quite often lead to adversarial relationships.The major grounds for claims were identified through studying the contract documents where claims had been made.Increase in scope;change orders;errors in contract documents;inclement weather;inflation;delay in possessing the site;and change in the tax policy were the most prevalent grounds for making claims.Problems identified in claiming process include delays in getting approval;information on claims not reliable;hostility from the parties involved;pricing of claims;delays in effecting payment when approved;and overzealous contract interpretation leading to misunderstanding and delays Using a survey on project managers for 64 contractors and their corresponding clients or their representatives,the major ways in which it can be reduced were identified as being thoroughness during the design phase;providing for inflation;proper planning of works;using prequalified contractors;and proper documentation of records.Clients have a big role to play in reducing claims.展开更多
The construction phase of a project is a critical factor that significantly impacts its overall success.The construction environment is characterized by uncertainty and dynamism,involving nonlinear relationships among...The construction phase of a project is a critical factor that significantly impacts its overall success.The construction environment is characterized by uncertainty and dynamism,involving nonlinear relationships among various factors that affect construction quality.This study utilized 987 construction inspection records from 1993 to 2022,obtained from the Taiwan residents Public Construction Management Information System(PCMIS),to determine the relationships between construction factors and quality.First,fuzzy logic was applied to calculate the weights of 499 defects,and 25 critical construction factors were selected based on these weight values.Next,a deep neural network was used to identify the relationship between the critical construction factors(input variables)and construction quality(output variable).Finally,the prediction model’s performance was evaluated to confirm the impact of these critical construction factors on project outcomes.This study employed an innovative hybrid soft computing technique,com-bining fuzzy logic and an artificial neural network,to effectively predict the relationship between critical construction factors and construction quality,achieving a model accuracy of 96.08%.Project managers can utilize the findings of this study to enhance project management practices and establish effective construction management strategies,thereby improving project construction quality.展开更多
The development and utilization of lunar resources are entering a critical stage.Immediate focus is needed on key technologies for in-situ resource utilization(ISRU)and lunar base construction.This paper comparatively...The development and utilization of lunar resources are entering a critical stage.Immediate focus is needed on key technologies for in-situ resource utilization(ISRU)and lunar base construction.This paper comparatively analyzes the basic characteristics of lunar regolith samples returned from Chang'e-5(CE-5),Apollo,and Luna missions,focusing on their physical,mechanical,mineral,chemical,and morphological parameters.Given the limited availability of lunar regolith,more than 50 lunar regolith simulants are summarized.The differences between lunar regolith and simulants concerning these parameters are discussed.To facilitate the construction of lunar bases,this article summarizes the advancements in research on construction materials derived from lunar regolith simulants.Based on statistical results,lunar regolith simulant-based composites are classified into 5 types by their strengthening and toughening mechanisms,and a comprehensive analysis of molding methods,preparation conditions,and mechanical properties is conducted.Furthermore,the potential lunar base construction forms are reviewed,and the adaptability of lunar regolith simulant-based composites and lunar base construction methods are proposed.The key demands of lunar bases constructed with lunar regolith-based composites are discussed,including energy demand,in-situ buildability,service performance,and structural availability.This progress contributes to providing essential material and methodological support for future lunar construction.展开更多
Introduction: Work-related accidents are frequent and serious in the construction sector. The aim of the study was to determine the frequency and factors associated with occupational accidents on the construction site...Introduction: Work-related accidents are frequent and serious in the construction sector. The aim of the study was to determine the frequency and factors associated with occupational accidents on the construction site of a referral hospital in Benin. Methods: A cross-sectional study was carried out. The sample size was calculated using the Schwartz form adjusted for the number of workers on site and was 129 workers. Random sampling was used. The dependent variable was work-related accidents. The other variables were socio-demographic and occupational characteristics. Data were collected through a questionnaire survey. Medians and proportions were calculated. An association was sought using Chi-square and Fisher tests with a threshold of p Results: A total of 132 workers were included. Their median age was 30 years with an ITQ of [27 - 38];men were the most represented 126 (95.45%) with a level of education higher than or equal to high school in 101 (76.52%) and in the majority with a permanent status 85 (64.39%). Seniority of more than 5 years was observed in 92 (69.7%). Workers working more than 8 hours of overtime per week numbered 57 (43.18%). Exposure to vibrating objects was 49 (37.12%). In terms of psychosocial constraints, 82.58% had high psychological demands;79.53% low decision-making latitude;50.76% low social support. The frequency of work-related accidents was 6.82%, and the only associated factor was the type of worker (p = 0.016). On the other hand, there were 10.2% accidents among workers handling vibrating objects versus 4.98% among those not using them. With regard to psychosocial constraints, the following frequencies were recorded respectively: 6.42% among those with high psychological demand versus 8.7% among those with low psychological demand;7.62% among those with low decision-making latitude versus 3.7% among those with high decision-making latitude;8.96% among those with low social support versus 4.62% among those with high support. Conclusion: Work-related accidents on construction sites must be avoided by all possible means including the management of psychosocial constraints.展开更多
Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instr...Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instruction-brief and instruction-category, and constructing test suite. Consequently, this approach is adopted to test oven embedded system, and detail process is deeply discussed. As a result, the factual result indicates that the “instruction-category” approach can be effectively applied in embedded system testing as a black-box method for conformity testing.展开更多
In the context of China’s economic development and population aging,the innovation and exploration of the old-age care model has emerged as a new community transformation and development direction.Given the differing...In the context of China’s economic development and population aging,the innovation and exploration of the old-age care model has emerged as a new community transformation and development direction.Given the differing needs and characteristics of individuals across the lifespan,it is evident that a design approach that incorporates mixed-age integration and mutual-help communities is a viable strategy for enhancing intergenerational exchanges.This entails the creation of a diverse and open community that is conducive to habitation for individuals of all ages,encompassing the full spectrum of needs,from those of young children to the elderly.Such a community must be designed and constructed with the population in mind,from the initial planning and design stages to the operational phase.This encompasses a comprehensive range of services,including food,clothing,housing,transportation,and medical care and recreation.展开更多
Lunar habitat construction is crucial for successful lunar exploration missions.Due to the limitations of transportation conditions,extensive global research has been conducted on lunar in situ material processing tec...Lunar habitat construction is crucial for successful lunar exploration missions.Due to the limitations of transportation conditions,extensive global research has been conducted on lunar in situ material processing techniques in recent years.The aim of this paper is to provide a comprehensive review,precise classification,and quantitative evaluation of these approaches,focusing specifically on four main approaches:reaction solidification(RS),sintering/melting(SM),bonding solidification(BS),and confinement formation(CF).Eight key indicators have been identified for the construction of low-cost and highperformance systems to assess the feasibility of these methods:in situ material ratio,curing temperature,curing time,implementation conditions,compressive strength,tensile strength,curing dimensions,and environmental adaptability.The scoring thresholds are determined by comparing the construction requirements with the actual capabilities.Among the evaluated methods,regolith bagging has emerged as a promising option due to its high in situ material ratio,low time requirement,lack of hightemperature requirements,and minimal shortcomings,with only the compressive strength falling below the neutral score.The compressive strength still maintains a value of 2–3 MPa.The proposed construction scheme utilizing regolith bags offers numerous advantages,including rapid and large-scale construction,ensured tensile strength,and reduced reliance on equipment and energy.In this study,guidelines for evaluating regolith solidification techniques are provided,and directions for improvement are offered.The proposed lunar habitat design based on regolith bags is a practical reference for future research.展开更多
As buildings evolve to meet the challenges of energy efficiency and indoor comfort,phase change materials(PCM)emerge as a promising solution due to their ability to store and release latent heat.This paper explores th...As buildings evolve to meet the challenges of energy efficiency and indoor comfort,phase change materials(PCM)emerge as a promising solution due to their ability to store and release latent heat.This paper explores the transformative impact of incorporating PCMon the hygrothermal dynamics of multi-zone constructions.The study focuses on analyzing heat transfer,particularly through thermal conduction,in a wall containing PCM.A novel approach was proposed,wherein the studied system(sensitive balance)interacts directly with a latent balance to realistically define the behavior of specific humidity and mass flow rates.In addition,a numerical model implemented in MATLAB software has been developed to investigate the effect of integrating PCM on the hygrothermal balances inside the building.The obtained results indicate a consistent response in internal temperatures,specific humidity,and mass flow rates,with temperature differences ranging from 5℃to 13℃and a maximum phase shift of 13 h.In addition,the findings provided valuable insights into optimizing the design and performance of multi-zone constructions,offering a sustainable pathway for enhancing building resilience and occupant well-being.展开更多
Space is both a product and a producer of social relations.In the spatial domain,gender blindness has long existed,limiting women’s rights of access to and use of space,leading to structural oppression of women’s ri...Space is both a product and a producer of social relations.In the spatial domain,gender blindness has long existed,limiting women’s rights of access to and use of space,leading to structural oppression of women’s rights,and giving rise to new gender inequalities.The barrier-free environment construction has the functions of eliminating physical barriers and generating societal norms,and when combined with social changes,can facilitate justice correction across multiple dimensions.However,barrier-free environment construction itself,as a means of justice correction,also suffers from gender blindness.There remains room for improvement in the areas of facility construction,information exchange,and social services within the realm of barrier-free environments.In response to this phenomenon,gender equality offers a new critical perspective.Therefore,integrating a gender perspective into the barrier-free environment construction,focusing on the spatial rights of women,especially groups with multiple vulnerabilities,such as disabled women and elderly women,can contribute to the advancement towards spatial justice.展开更多
The development of the construction industry is shifting towards low-carbon construction,so it is necessary to improve and optimize related construction concepts,methods,and processes.By improving resource and energy ...The development of the construction industry is shifting towards low-carbon construction,so it is necessary to improve and optimize related construction concepts,methods,and processes.By improving resource and energy control efficiency in building projects,minimizing construction waste,and reducing environmental impact,a foundation for the sustainable development of the industry can be established.This paper mainly analyzes the significance of low-carbon energy-saving construction technology and the control factors of construction,summarizes the status quo of the development of building energy-saving construction,and puts forward strategies for applying building energy-saving construction technology.These strategies serve to achieve low-carbon and energy-saving goals to promote the healthy development of energy-saving construction.展开更多
With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing facto...With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing factors, human unsafe behavior stands out as a primary cause for these incidents. This study aims to assess the human reliability of tower crane operations on smart construction sites. To proactively enhance safety measures, the research employs text mining techniques (TF-IDF-Truncated SVD-Complement NB) to identify patterns of human errors among tower crane operators. Building upon the SHEL model, the study categorizes behavioral factors affecting human reliability in the man-machine interface, leading to the establishment of the Performance Shaping Factors (PSFs) system. Furthermore, the research constructs an error impact indicator system for the intelligent construction site tower crane operator interface. Using the DEMATEL method, it analyzes the significance of various factors influencing human errors in tower crane operations. Additionally, the ISM-MICMAC method is applied to unveil the hierarchical relationships and driving-dependent connections among these influencing factors. The findings indicate that personal state, operating procedures, and physical environment directly impact human errors, while personal capability, technological environment, and one fundamental organizational management factor contribute indirectly. .展开更多
Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic t...Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li<sup> </sup>. Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO<sub>4</sub>, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.展开更多
This article analyzes the path to constructing first-class undergraduate majors in finance,using the finance major as a case study.Through analysis,it aims to offer reference and inspiration for enhancing the quality ...This article analyzes the path to constructing first-class undergraduate majors in finance,using the finance major as a case study.Through analysis,it aims to offer reference and inspiration for enhancing the quality of finance education in China and supporting the healthy development of the financial industry.The article begins by examining the current status of finance majors,followed by an analysis of the necessity for establishing first-class undergraduate programs.Finally,it provides a detailed exploration of the specific methods for building such programs in finance.The findings indicate that accelerating the construction of first-class undergraduate finance majors is a long-term and challenging task that requires the combined efforts of the government,universities,industry,and various social sectors.Through comprehensive and innovative reforms in areas such as training objectives and positioning,curriculum development,teaching teams,and practical instruction,the quality and level of finance education can be effectively elevated,thereby cultivating more high-caliber financial professionals who meet the demands of the times.展开更多
Against the backdrop of continuous development in the field of education,universities are encouraged to innovate their talent cultivation systems and objectives.The deep integration of industry and education has emerg...Against the backdrop of continuous development in the field of education,universities are encouraged to innovate their talent cultivation systems and objectives.The deep integration of industry and education has emerged as an effective strategy,aligning with the basic requirements of the new engineering education initiative and exerting a positive impact on socioeconomic development.However,an analysis of the current state of industry-education integration in universities reveals several issues that require optimization,affecting the ultimate effectiveness of integration.To optimize this phenomenon and achieve high-quality development,universities need to further explore the construction of a deep integration model of industry and education,adhering to corresponding principles to form a comprehensive system.On this basis,pathways for deep industry-education integration can be summarized.展开更多
基金The Guangdong Basic and Applied Basic Research Foundation(Grant#2023A1515010535).
文摘Complex bridge structures designed and constructed by humans often necessitate extensive on-site execution,which carries inherent risks.Consequently,a variety of engineering practices are employed to monitor bridge construction.This paper presents a case study of a large-span prestressed concrete(PC)variable-section continuous girder bridge in China,proposing a feedback system for construction monitoring and establishing a finite element(FE)analysis model for the entire bridge.The alignment of the completed bridge adheres to the initial design expectations,with maximum displacement and pre-arch differences from the ideal state measuring 6.39 and 17.7 mm,respectively,which were less than the 20 mm limit required by the specification.Additionally,the stress monitoring showed that the maximum compressive stress was 10.44 MPa,which was 7.5%different from the finite element results,and better predicted the most unfavorable possible location.These results demonstrate that a scientifically rigorous construction monitoring and feedback system can ensure the safety of bridge construction and meet the expected construction standards.The findings presented in this paper provide valuable insights for bridge construction monitoring practices.
基金supported by the National Key Research and Development Program of China(2023YFB3711300 and 2021YFF0500300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(2023-XZ-90 and 2023-JB-09-10)the National Key Research and Development Program of China(2021YFF0500300).
文摘The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.
基金Guizhou Provincial University Humanities and Social Sciences Research Project in 2024"Enhancing the Development of New Productive Forces through University Technological Innovation and Intellectual Property Management"(2024RW256)Guizhou University of Commerce Research Project in 2022"Study on the Ideas and Pathways to Drive Agricultural Powerhouse through Digital Economy"(2022XJZX315)。
文摘With the rapid development of globalization and information technology,intellectual property has been one of the key drivers of economic growth,and the construction of intellectual property system has become an important criterion for measuring the quality of business environment.This article is intended to explore the current status of intellectual property system construction in China,the challenges,and its relationship with the business environment,to propose the corresponding countermeasures and suggestions.The study finds that the legal system of intellectual property in China is gradually improving,and judicial and administrative protection are continuously strengthened.However,the challenges still remain such as frequent infringements,rights hard to protect and insufficient international cooperation.These issues not only affect the legitimate rights and interests of innovation entities,but also for the market fairness and the level of the business environment.Therefore,this article proposes that strengthening the perfection of the intellectual property legal system,enhancing intellectual property services and support capabilities,strengthening international cooperation and exchanges,and accelerating the cultivation of composite talents.It aims to provide theoretical references for the construction of intellectual property system and the optimization of the business environment,promote the high-quality development of economy and enhance the global competitiveness of the country.
基金supported by the National Natural Science Foundation of China(41871184)the National Social Science Fund of China(21ZDA056)the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences(10-IAED-ZT-01-2023and 10-IAED-RC-07-2023)。
文摘Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.
基金supported by National Natural Science Foundation of China(Grant Nos.4203070 and 41977217)the Key Research&Development Program of Shaanxi Province(Grant No.2020ZDLSF06-03).
文摘Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.
基金carried out by Khatatbeh A.A while on sabbatical leave from Al al-Bayt University for the academic year(2023/2024)The author appreciates the support from Al al-Bayt University president and deans’council members.
文摘Professional and trade skills are required for handling the construction related projects;Construction industries of the present day however lack useful information concerning different practices,patterns and trends involved in risk management.Considering this,the present study focuses on the aforementioned variables of risk management by quantitative analysis specifically in the domain of construction industry.This study has used IBM’s SPSS(Statistical Package for Social Sciences)version 25.0 to analyze the results.This study is an initiative to assess the impact of risk management in the construction sector of Jordan.It will assist the construction sector for exploring the limitations with respect to integrate effective risk management.A sense of competition will be developed through a comparison of risk factors of construction projects among the project stakeholders such as contractors should enhance their risk management practices.
文摘The increasing cost of infrastructure development risks stifling national investment plans.Many projects in Uganda have suffered because of the frequency and magnitude of claims made by parties involved especially the contractors.As a result,the construction industry is plagued with claims which quite often lead to adversarial relationships.The major grounds for claims were identified through studying the contract documents where claims had been made.Increase in scope;change orders;errors in contract documents;inclement weather;inflation;delay in possessing the site;and change in the tax policy were the most prevalent grounds for making claims.Problems identified in claiming process include delays in getting approval;information on claims not reliable;hostility from the parties involved;pricing of claims;delays in effecting payment when approved;and overzealous contract interpretation leading to misunderstanding and delays Using a survey on project managers for 64 contractors and their corresponding clients or their representatives,the major ways in which it can be reduced were identified as being thoroughness during the design phase;providing for inflation;proper planning of works;using prequalified contractors;and proper documentation of records.Clients have a big role to play in reducing claims.
文摘The construction phase of a project is a critical factor that significantly impacts its overall success.The construction environment is characterized by uncertainty and dynamism,involving nonlinear relationships among various factors that affect construction quality.This study utilized 987 construction inspection records from 1993 to 2022,obtained from the Taiwan residents Public Construction Management Information System(PCMIS),to determine the relationships between construction factors and quality.First,fuzzy logic was applied to calculate the weights of 499 defects,and 25 critical construction factors were selected based on these weight values.Next,a deep neural network was used to identify the relationship between the critical construction factors(input variables)and construction quality(output variable).Finally,the prediction model’s performance was evaluated to confirm the impact of these critical construction factors on project outcomes.This study employed an innovative hybrid soft computing technique,com-bining fuzzy logic and an artificial neural network,to effectively predict the relationship between critical construction factors and construction quality,achieving a model accuracy of 96.08%.Project managers can utilize the findings of this study to enhance project management practices and establish effective construction management strategies,thereby improving project construction quality.
基金supported by National Natural Science Foundation of China(No.42172319)the Fundamental Research Funds for the Central Universities(No.2023ZKPYLJ01)。
文摘The development and utilization of lunar resources are entering a critical stage.Immediate focus is needed on key technologies for in-situ resource utilization(ISRU)and lunar base construction.This paper comparatively analyzes the basic characteristics of lunar regolith samples returned from Chang'e-5(CE-5),Apollo,and Luna missions,focusing on their physical,mechanical,mineral,chemical,and morphological parameters.Given the limited availability of lunar regolith,more than 50 lunar regolith simulants are summarized.The differences between lunar regolith and simulants concerning these parameters are discussed.To facilitate the construction of lunar bases,this article summarizes the advancements in research on construction materials derived from lunar regolith simulants.Based on statistical results,lunar regolith simulant-based composites are classified into 5 types by their strengthening and toughening mechanisms,and a comprehensive analysis of molding methods,preparation conditions,and mechanical properties is conducted.Furthermore,the potential lunar base construction forms are reviewed,and the adaptability of lunar regolith simulant-based composites and lunar base construction methods are proposed.The key demands of lunar bases constructed with lunar regolith-based composites are discussed,including energy demand,in-situ buildability,service performance,and structural availability.This progress contributes to providing essential material and methodological support for future lunar construction.
文摘Introduction: Work-related accidents are frequent and serious in the construction sector. The aim of the study was to determine the frequency and factors associated with occupational accidents on the construction site of a referral hospital in Benin. Methods: A cross-sectional study was carried out. The sample size was calculated using the Schwartz form adjusted for the number of workers on site and was 129 workers. Random sampling was used. The dependent variable was work-related accidents. The other variables were socio-demographic and occupational characteristics. Data were collected through a questionnaire survey. Medians and proportions were calculated. An association was sought using Chi-square and Fisher tests with a threshold of p Results: A total of 132 workers were included. Their median age was 30 years with an ITQ of [27 - 38];men were the most represented 126 (95.45%) with a level of education higher than or equal to high school in 101 (76.52%) and in the majority with a permanent status 85 (64.39%). Seniority of more than 5 years was observed in 92 (69.7%). Workers working more than 8 hours of overtime per week numbered 57 (43.18%). Exposure to vibrating objects was 49 (37.12%). In terms of psychosocial constraints, 82.58% had high psychological demands;79.53% low decision-making latitude;50.76% low social support. The frequency of work-related accidents was 6.82%, and the only associated factor was the type of worker (p = 0.016). On the other hand, there were 10.2% accidents among workers handling vibrating objects versus 4.98% among those not using them. With regard to psychosocial constraints, the following frequencies were recorded respectively: 6.42% among those with high psychological demand versus 8.7% among those with low psychological demand;7.62% among those with low decision-making latitude versus 3.7% among those with high decision-making latitude;8.96% among those with low social support versus 4.62% among those with high support. Conclusion: Work-related accidents on construction sites must be avoided by all possible means including the management of psychosocial constraints.
文摘Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instruction-brief and instruction-category, and constructing test suite. Consequently, this approach is adopted to test oven embedded system, and detail process is deeply discussed. As a result, the factual result indicates that the “instruction-category” approach can be effectively applied in embedded system testing as a black-box method for conformity testing.
文摘In the context of China’s economic development and population aging,the innovation and exploration of the old-age care model has emerged as a new community transformation and development direction.Given the differing needs and characteristics of individuals across the lifespan,it is evident that a design approach that incorporates mixed-age integration and mutual-help communities is a viable strategy for enhancing intergenerational exchanges.This entails the creation of a diverse and open community that is conducive to habitation for individuals of all ages,encompassing the full spectrum of needs,from those of young children to the elderly.Such a community must be designed and constructed with the population in mind,from the initial planning and design stages to the operational phase.This encompasses a comprehensive range of services,including food,clothing,housing,transportation,and medical care and recreation.
基金supported by the National Natural Science Foundation of China(42241109)the Guoqiang Institute,Tsinghua University(2021GQG1001)the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘Lunar habitat construction is crucial for successful lunar exploration missions.Due to the limitations of transportation conditions,extensive global research has been conducted on lunar in situ material processing techniques in recent years.The aim of this paper is to provide a comprehensive review,precise classification,and quantitative evaluation of these approaches,focusing specifically on four main approaches:reaction solidification(RS),sintering/melting(SM),bonding solidification(BS),and confinement formation(CF).Eight key indicators have been identified for the construction of low-cost and highperformance systems to assess the feasibility of these methods:in situ material ratio,curing temperature,curing time,implementation conditions,compressive strength,tensile strength,curing dimensions,and environmental adaptability.The scoring thresholds are determined by comparing the construction requirements with the actual capabilities.Among the evaluated methods,regolith bagging has emerged as a promising option due to its high in situ material ratio,low time requirement,lack of hightemperature requirements,and minimal shortcomings,with only the compressive strength falling below the neutral score.The compressive strength still maintains a value of 2–3 MPa.The proposed construction scheme utilizing regolith bags offers numerous advantages,including rapid and large-scale construction,ensured tensile strength,and reduced reliance on equipment and energy.In this study,guidelines for evaluating regolith solidification techniques are provided,and directions for improvement are offered.The proposed lunar habitat design based on regolith bags is a practical reference for future research.
基金supported in entire part by the Biomaterials and Transport Phenomena LaboratoryAgreementNo.30303-12-2003,at theUniversity of Medea.
文摘As buildings evolve to meet the challenges of energy efficiency and indoor comfort,phase change materials(PCM)emerge as a promising solution due to their ability to store and release latent heat.This paper explores the transformative impact of incorporating PCMon the hygrothermal dynamics of multi-zone constructions.The study focuses on analyzing heat transfer,particularly through thermal conduction,in a wall containing PCM.A novel approach was proposed,wherein the studied system(sensitive balance)interacts directly with a latent balance to realistically define the behavior of specific humidity and mass flow rates.In addition,a numerical model implemented in MATLAB software has been developed to investigate the effect of integrating PCM on the hygrothermal balances inside the building.The obtained results indicate a consistent response in internal temperatures,specific humidity,and mass flow rates,with temperature differences ranging from 5℃to 13℃and a maximum phase shift of 13 h.In addition,the findings provided valuable insights into optimizing the design and performance of multi-zone constructions,offering a sustainable pathway for enhancing building resilience and occupant well-being.
基金the stagedresult of “General Secretary Xi Jinping’s Expositions on Respecting and Protecting Human Rights”(Project Approval Number 22ZD004)a major project of the National Social Science Fund of China。
文摘Space is both a product and a producer of social relations.In the spatial domain,gender blindness has long existed,limiting women’s rights of access to and use of space,leading to structural oppression of women’s rights,and giving rise to new gender inequalities.The barrier-free environment construction has the functions of eliminating physical barriers and generating societal norms,and when combined with social changes,can facilitate justice correction across multiple dimensions.However,barrier-free environment construction itself,as a means of justice correction,also suffers from gender blindness.There remains room for improvement in the areas of facility construction,information exchange,and social services within the realm of barrier-free environments.In response to this phenomenon,gender equality offers a new critical perspective.Therefore,integrating a gender perspective into the barrier-free environment construction,focusing on the spatial rights of women,especially groups with multiple vulnerabilities,such as disabled women and elderly women,can contribute to the advancement towards spatial justice.
基金Research on Zero Emission Campus Construction Based on Plant Community Optimization(Project number:KJQN202305605)。
文摘The development of the construction industry is shifting towards low-carbon construction,so it is necessary to improve and optimize related construction concepts,methods,and processes.By improving resource and energy control efficiency in building projects,minimizing construction waste,and reducing environmental impact,a foundation for the sustainable development of the industry can be established.This paper mainly analyzes the significance of low-carbon energy-saving construction technology and the control factors of construction,summarizes the status quo of the development of building energy-saving construction,and puts forward strategies for applying building energy-saving construction technology.These strategies serve to achieve low-carbon and energy-saving goals to promote the healthy development of energy-saving construction.
文摘With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing factors, human unsafe behavior stands out as a primary cause for these incidents. This study aims to assess the human reliability of tower crane operations on smart construction sites. To proactively enhance safety measures, the research employs text mining techniques (TF-IDF-Truncated SVD-Complement NB) to identify patterns of human errors among tower crane operators. Building upon the SHEL model, the study categorizes behavioral factors affecting human reliability in the man-machine interface, leading to the establishment of the Performance Shaping Factors (PSFs) system. Furthermore, the research constructs an error impact indicator system for the intelligent construction site tower crane operator interface. Using the DEMATEL method, it analyzes the significance of various factors influencing human errors in tower crane operations. Additionally, the ISM-MICMAC method is applied to unveil the hierarchical relationships and driving-dependent connections among these influencing factors. The findings indicate that personal state, operating procedures, and physical environment directly impact human errors, while personal capability, technological environment, and one fundamental organizational management factor contribute indirectly. .
文摘Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li<sup> </sup>. Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO<sub>4</sub>, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.
基金Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(Program No.23JK0166)。
文摘This article analyzes the path to constructing first-class undergraduate majors in finance,using the finance major as a case study.Through analysis,it aims to offer reference and inspiration for enhancing the quality of finance education in China and supporting the healthy development of the financial industry.The article begins by examining the current status of finance majors,followed by an analysis of the necessity for establishing first-class undergraduate programs.Finally,it provides a detailed exploration of the specific methods for building such programs in finance.The findings indicate that accelerating the construction of first-class undergraduate finance majors is a long-term and challenging task that requires the combined efforts of the government,universities,industry,and various social sectors.Through comprehensive and innovative reforms in areas such as training objectives and positioning,curriculum development,teaching teams,and practical instruction,the quality and level of finance education can be effectively elevated,thereby cultivating more high-caliber financial professionals who meet the demands of the times.
基金2023 Annual Project of the China Association for Construction Education“Research on the Development Path of Private Colleges and Industry Integration in Liaoning Province Under the Strategy of Intelligent Manufacturing Strong Province”(Project number:2023239)。
文摘Against the backdrop of continuous development in the field of education,universities are encouraged to innovate their talent cultivation systems and objectives.The deep integration of industry and education has emerged as an effective strategy,aligning with the basic requirements of the new engineering education initiative and exerting a positive impact on socioeconomic development.However,an analysis of the current state of industry-education integration in universities reveals several issues that require optimization,affecting the ultimate effectiveness of integration.To optimize this phenomenon and achieve high-quality development,universities need to further explore the construction of a deep integration model of industry and education,adhering to corresponding principles to form a comprehensive system.On this basis,pathways for deep industry-education integration can be summarized.