Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising techniqu...Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.展开更多
Three-dimensional(3D)printing technology has opened a new paradigm to controllably and reproducibly fabricate bioengineered neural constructs for potential applications in repairing injured nervous tissues or producin...Three-dimensional(3D)printing technology has opened a new paradigm to controllably and reproducibly fabricate bioengineered neural constructs for potential applications in repairing injured nervous tissues or producing in vitro nervous tissue models.However,the complexity of nervous tissues poses great challenges to 3D-printed bioengineered analogues,which should possess diverse architectural/chemical/electrical functionalities to resemble the native growth microenvironments for functional neural regeneration.In this work,we provide a state-of-the-art review of the latest development of 3D printing for bioengineered neural constructs.Various 3D printing techniques for neural tissue-engineered scaffolds or living cell-laden constructs are summarized and compared in terms of their unique advantages.We highlight the advanced strategies by integrating topographical,biochemical and electroactive cues inside 3D-printed neural constructs to replicate in vivo-like microenvironment for functional neural regeneration.The typical applications of 3D-printed bioengineered constructs for in vivo repair of injured nervous tissues,bio-electronics interfacing with native nervous system,neural-on-chips as well as brain-like tissue models are demonstrated.The challenges and future outlook associated with 3D printing for functional neural constructs in various categories are discussed.展开更多
The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity mate...The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductiv-ity material are obtained by numerically simulating the evolution and degeneration process ac-cording to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manu-facture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the do-main with a uniform heat source and high conductivity ratio of the inserting material to the sub-strate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.展开更多
To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development...To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development.This involved exploring the deep integration of next-generation artificial intelligence technologies,such as sensing technology,automatic control technology,big data technology,deep learning,and machine vision,with key operational processes,including TBM excavation,direction adjustment,step changes,inverted arch block assembly,material transportation,and operation status assurance.The results of this integration are summarized as follows.(1)TBM key excavation parameter prediction algorithm was developed with an accuracy rate exceeding 90%.The TBM intelligent step-change control algorithm,based on machine vision,achieved an image segmentation accuracy rate of 95%and gripper shoe positioning error of±5 mm.(2)An automatic positioning system for inverted arch blocks was developed,enabling real-time perception of the spatial position and deviation during the assembly process.The system maintains an elevation positioning deviation within±3 mm and a horizontal positioning deviation within±10 mm,reducing the number of surveyors in each work team.(3)A TBM intelligent rail transportation system that achieves real-time human-machine positioning,automatic switch opening and closing,automatic obstacle avoidance,intelligent transportation planning,and integrated scheduling and command was designed.Each locomotive formation reduces one shunter and improves comprehensive transportation efficiency by more than 20%.(4)Intelligent analysis and prediction algorithms were developed to monitor and predict the trends of the hydraulic and gear oil parameters in real time,enhancing the proactive maintenance and system reliability.展开更多
Bioprinting is a rapidly developing technology for the precise design and manufacture of tissues in various biological systems or organs.Coaxial extrusion bioprinting,an emergent branch,has demonstrated a strong poten...Bioprinting is a rapidly developing technology for the precise design and manufacture of tissues in various biological systems or organs.Coaxial extrusion bioprinting,an emergent branch,has demonstrated a strong potential to enhance bioprinting's engineering versatility.Coaxial bioprinting assists in the fabrication of complex tissue constructs,by enabling concentric deposition of biomaterials.The fabricated tissue constructs started with simple,tubular vasculature but have been substantially developed to integrate complex cell composition and self-assembly,ECM patterning,controlled release,and multi-material gradient profiles.This review article begins with a brief overview of coaxial printing history,followed by an introduction of crucial engineering components.Afterward,we review the recent progress and untapped potential in each specific organ or biological system,and demonstrate how coaxial bioprinting facilitates the creation of tissue constructs.Ultimately,we conclude that this growing technology will contribute significantly to capabilities in the fields of in vitro modeling,pharmaceutical development,and clinical regenerative medicine.展开更多
The ready-to-use,structure-supporting hydrogel bioink can shorten the time for ink preparation,ensure cell dispersion,and maintain the preset shape/microstructure without additional assistance during printing.Meanwhil...The ready-to-use,structure-supporting hydrogel bioink can shorten the time for ink preparation,ensure cell dispersion,and maintain the preset shape/microstructure without additional assistance during printing.Meanwhile,ink with high permeability might facilitate uniform cell growth in biological constructs,which is beneficial to homogeneous tissue repair.Unfortunately,current bioinks are hard to meet these requirements simultaneously in a simple way.Here,based on the fast dynamic crosslinking of aldehyde hyaluronic acid(AHA)/N-carboxymethyl chitosan(CMC)and the slow stable crosslinking of gelatin(GEL)/4-arm poly(ethylene glycol)succinimidyl glutarate(PEG-SG),we present a time-sharing structure-supporting(TSHSP)hydrogel bioink with high permeability,containing 1%AHA,0.75%CMC,1%GEL and 0.5%PEG-SG.The TSHSP hydrogel can facilitate printing with proper viscoelastic property and self-healing behavior.By crosslinking with 4%PEG-SG for only 3 min,the integrity of the cell-laden construct can last for 21 days due to the stable internal and external GEL/PEG-SG networks,and cells manifested long-term viability and spreading morphology.Nerve-like,muscle-like,and cartilage-like in vitro constructs exhibited homogeneous cell growth and remarkable biological specificities.This work provides not only a convenient and practical bioink for tissue engineering,targeted cell therapy,but also a new direction for hydrogel bioink development.展开更多
Scientific and technological advancements are rapidly transforming underground engineering,shifting from labor-intensive,time-consuming methods to automated,real-time systems.This timely and comprehensive review cover...Scientific and technological advancements are rapidly transforming underground engineering,shifting from labor-intensive,time-consuming methods to automated,real-time systems.This timely and comprehensive review covers in-situ testing,intelligent monitoring,and geophysical testing methods,highlighting fundamental principles,testing apparatuses,data processing techniques,and engineering applications.The state-of-the-art summary emphasizes not only cutting-edge innovations for complex and harsh environments but also the transformative role of artificial intelligence and machine learning in data interpretations.The integration of big data and advanced algorithms is particularly impactful,enabling the identification,prediction,and mitigation of potential risks in underground projects.Key aspects of the discussion include detection capabilities,method integration,and data convergence of intelligent technologies to drive enhanced safety,operational efficiency,and predictive reliability.The review also examines future trends in intelligent technologies,emphasizing unified platforms that combine multiple methods,real-time data,and predictive analytics.These advancements are shaping the evolution of underground construction and maintenance,aiming for risk-free,high-efficiency underground engineering.展开更多
To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission leve...To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration method.We investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the future.The results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance rate.Differenceswere observed amongmachinery types,with low-power engine forklifts showing higher smoke levels.The NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively small.Engine rated net power had the most significant impact on NO_(x)emissions.Thus,NO_(x)emissions from construction machinery need further attention.Furthermore,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission limits.In the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.展开更多
The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination ...The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination of microbial technology and a rotary kiln process was employed to expedite the carbonation of steel slag for fixation from cement kiln flue gas.This approach resulted in a significant increase in the CO_(2)-fixation rate,with a CO_(2)-fixation ratio of approximately 10%achieved within 1 h and consistent performance across different seasons throughout the year.Investigation revealed that both the CO_(2)-fixation ratio and the particle fineness are pivotal for increasing the soundness and reactivity of steel slag.When the CO_(2)-fixation ratio exceeds 8%and the specific surface area is at least 300 m2∙kg−1,the soundness issue of steel slag can be effectively addressed,facilitating the safe utilization of steel slag.Residual microbes present in the carbonated steel slag powder act as nucleating sites,increasing the hydration rate of the silicate phases in Portland cement to form more hydration products.Microbial regulation results in the biogenic calcium carbonate having smaller crystal sizes,which facilitates the formation of monocarboaluminate to increase the strength of hardened cement paste.At the same CO_(2)-fixation ratio,microbial mineralized steel slag powder exhibits greater hydration activity than carbonated steel slag powder.With a CO_(2)-fixation ratio of 10%and a specific surface area of 600 m^(2)∙kg^(−1),replacing 30%of cement clinker with microbial mineralized steel slag powder yields an activity index of 87.7%.This study provides a sustainable solution for reducing carbon emissions and safely and efficiently utilizing steel slag in the construction materials sector,while expanding the application scope of microbial technology.展开更多
Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.T...Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.To contribute to a better understanding of the state of the art of smart techniques for engineering projects,this paper provides a comprehensive review of multi-criteria decision-making(MCDM)techniques,intelligent techniques,and their applications in CEM.First,a comprehensive framework detailing smart technologies for construction projects is developed.Next,the characteristics of CEM are summarized.A bibliometric review is then conducted to investigate the keywords,journals,and clusters related to the application of smart techniques in CEM during 2000-2022.Recent advancements in intelligent techniques are also discussed under the following six topics:①big data technology;②computer vision;③speech recognition;④natural language processing;⑤machine learning;and⑥knowledge representation,understanding,and reasoning.The applications of smart techniques are then illustrated via underground space exploitation.Finally,future research directions for the sustainable development of smart construction are highlighted.展开更多
Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a s...Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a serious problem. A potential solution to this problem is to fabricate skin constructs using biomaterial scaffolds with or without cells. Bioprinting is being applied to address the need for skin tissues suitable for transplantation, and can lead to the development of skin equivalents for wound healing therapy. Here, we summarize strategies of bioprinting and review current advances of bioprinting of skin constructs. There will be challenges on the way of 3D bioprinting for skin regeneration, but we still believe bioprinting will be potential skills for wounds healing in the foreseeable future.展开更多
With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,off...With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.展开更多
The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have bec...The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have become a pivotal production tool in this context.Since the arm span of a single robot usually does not exceed 3 meters,it is not competent for producing large-scale building components.Accordingly,the extension of the robot,s working range is often achieved by external axes.Nevertheless,the coupling control of external axes and robots and their kinematic solution have become key challenges.The primary technical difficulties include customized construction robots,automatic solutions for external axes,fixed axis joints,and specific motion mode control.This paper proposes solutions to these difficulties,introduces the relevant basic concepts and algorithms in detail,and encapsulates these robotics principles and algorithm processes into the Grasshopper plug-in commonly used by architects to form the FURobot software platform.This platform effectively solves the above problems,lowers the threshold for architects,and improves production efficiency.The effectiveness of the algorithm and software in this paper is verified through simulation 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
In this paper, the concretely both reflective and coreflective subconstructs of the construct CFTSof Chang fuzzy topological spaces are characterized and their relationship to such subconstructs of stratifiedfuzzy top...In this paper, the concretely both reflective and coreflective subconstructs of the construct CFTSof Chang fuzzy topological spaces are characterized and their relationship to such subconstructs of stratifiedfuzzy topological spaces is investigated. Properties of a particular such subconstruct of CFTS, the constructof weak fuzzy neighborhood spaces, are discussed in detail. And it is proved that there exists exactly c suchsubconstructs between the subconstruct of weakly induced spaces and CFTS.展开更多
Our long-term objective is to develop a software toolbox for pre-embodiment design of complex and heterogeneous systems, such as cyber-physical systems. The novelty of this toolbox is that it uses system manifestation...Our long-term objective is to develop a software toolbox for pre-embodiment design of complex and heterogeneous systems, such as cyber-physical systems. The novelty of this toolbox is that it uses system manifestation features(SMFs) for transdisciplinary modeling of these systems. The main challenges of implementation of the toolbox are functional design- and language-independent computational realization of the warehouses, and systematic development and management of the various evolving implements of SMFs(genotypes, phenotypes, and instances). Therefore, an information schema construct(ISC) based approach is proposed to create the schemata of the associated warehouse databases and the above-mentioned SMF implements. ISCs logically arrange the data contents of SMFs in a set of relational tables of varying semantics. In this article we present the ISCs necessary for creation of genotypes and phenotypes. They increase the efficiency of the database development process and make the data relationships transparent. Our follow-up research focuses on the elaboration of the SMF instances based system modeling methodology.展开更多
Complementing our previous publications, this paper presents the information schema constructs （ISCs） that underpin the programming of specific system manifestation feature （SMF） orientated information management ...Complementing our previous publications, this paper presents the information schema constructs （ISCs） that underpin the programming of specific system manifestation feature （SMF） orientated information management and composing system models. First, we briefly present （1） the general process of pre-embodiment design with SMFs, （2） the procedures of creating genotypes and phenotypes of SMFs, （3） the specific procedure of instantiation of phenotypes of SMFs, and （4） the procedure of system model management and processing. Then, the chunks of information needed for instantiation of phenotypes of SMFs are discussed, and the ISCs designed for instantiation presented. Afterwards, the information management aspects of system modeling are addressed. Methodologically, system modeling involves （1） placement of phenotypes of SMF in the modeling space, （2） combining them towards the desired architecture and operation, （3） assigning values to the parameters and checking the satisfac- tion of constraints, and （4） storing the system model in the SMFs-based warehouse database. The final objective of the reported research is to develop an SMFs-based toolbox to support modeling of cyber-physical systems （CPSs）.展开更多
Taking modern indoor building construction as an example,this study analyzes the path planning and navigation of a smart plastering robot.It includes a basic introduction to smart plastering robots,an analysis of mult...Taking modern indoor building construction as an example,this study analyzes the path planning and navigation of a smart plastering robot.It includes a basic introduction to smart plastering robots,an analysis of multi-sensor fusion localization algorithms for smart plastering robots,and an analysis of path planning and navigation functions for smart plastering robots.It is hoped that through this analysis,a reference is provided for the path planning and navigation design of such robots to meet their practical application needs.展开更多
1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are cha...1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.展开更多
Construction work is an important component of social development,and its safety management is crucial for the protection of employees’lives,the efficient development of enterprises,and the social harmony and stabili...Construction work is an important component of social development,and its safety management is crucial for the protection of employees’lives,the efficient development of enterprises,and the social harmony and stability.Therefore,this paper explores the risk identification,risk estimation,risk evaluation,and control strategies of construction sites.It analyzes the research progress,current issues that need optimization,and future development directions,aiming to provide insights for the development of risk evaluation in construction sites.展开更多
文摘Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.
基金financially supported by the National Natural Science Foundation of China (52125501)OPEN Project (BHJ17C019)+4 种基金the Key Research Project of Shaanxi Province (2021LLRH-08)the Program for Innovation Team of Shaanxi Province (2023-CX-TD-17)the Natural Science Basic Research Program of Shaanxi Province (2023-JCQN-0543)the China Postdoctoral Science Foundation (2021M702597)the Fundamental Research Funds for the Central Universities
文摘Three-dimensional(3D)printing technology has opened a new paradigm to controllably and reproducibly fabricate bioengineered neural constructs for potential applications in repairing injured nervous tissues or producing in vitro nervous tissue models.However,the complexity of nervous tissues poses great challenges to 3D-printed bioengineered analogues,which should possess diverse architectural/chemical/electrical functionalities to resemble the native growth microenvironments for functional neural regeneration.In this work,we provide a state-of-the-art review of the latest development of 3D printing for bioengineered neural constructs.Various 3D printing techniques for neural tissue-engineered scaffolds or living cell-laden constructs are summarized and compared in terms of their unique advantages.We highlight the advanced strategies by integrating topographical,biochemical and electroactive cues inside 3D-printed neural constructs to replicate in vivo-like microenvironment for functional neural regeneration.The typical applications of 3D-printed bioengineered constructs for in vivo repair of injured nervous tissues,bio-electronics interfacing with native nervous system,neural-on-chips as well as brain-like tissue models are demonstrated.The challenges and future outlook associated with 3D printing for functional neural constructs in various categories are discussed.
基金This work was supported by the National Key Fundamental R&D Program of China (Grant No. G20000263).
文摘The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductiv-ity material are obtained by numerically simulating the evolution and degeneration process ac-cording to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manu-facture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the do-main with a uniform heat source and high conductivity ratio of the inserting material to the sub-strate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.
文摘To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development.This involved exploring the deep integration of next-generation artificial intelligence technologies,such as sensing technology,automatic control technology,big data technology,deep learning,and machine vision,with key operational processes,including TBM excavation,direction adjustment,step changes,inverted arch block assembly,material transportation,and operation status assurance.The results of this integration are summarized as follows.(1)TBM key excavation parameter prediction algorithm was developed with an accuracy rate exceeding 90%.The TBM intelligent step-change control algorithm,based on machine vision,achieved an image segmentation accuracy rate of 95%and gripper shoe positioning error of±5 mm.(2)An automatic positioning system for inverted arch blocks was developed,enabling real-time perception of the spatial position and deviation during the assembly process.The system maintains an elevation positioning deviation within±3 mm and a horizontal positioning deviation within±10 mm,reducing the number of surveyors in each work team.(3)A TBM intelligent rail transportation system that achieves real-time human-machine positioning,automatic switch opening and closing,automatic obstacle avoidance,intelligent transportation planning,and integrated scheduling and command was designed.Each locomotive formation reduces one shunter and improves comprehensive transportation efficiency by more than 20%.(4)Intelligent analysis and prediction algorithms were developed to monitor and predict the trends of the hydraulic and gear oil parameters in real time,enhancing the proactive maintenance and system reliability.
基金We thank Utah State University's College of Engineering Undergraduate Research Program(EURP)for supporting Andrew Kjar and Bailey McFarland.
文摘Bioprinting is a rapidly developing technology for the precise design and manufacture of tissues in various biological systems or organs.Coaxial extrusion bioprinting,an emergent branch,has demonstrated a strong potential to enhance bioprinting's engineering versatility.Coaxial bioprinting assists in the fabrication of complex tissue constructs,by enabling concentric deposition of biomaterials.The fabricated tissue constructs started with simple,tubular vasculature but have been substantially developed to integrate complex cell composition and self-assembly,ECM patterning,controlled release,and multi-material gradient profiles.This review article begins with a brief overview of coaxial printing history,followed by an introduction of crucial engineering components.Afterward,we review the recent progress and untapped potential in each specific organ or biological system,and demonstrate how coaxial bioprinting facilitates the creation of tissue constructs.Ultimately,we conclude that this growing technology will contribute significantly to capabilities in the fields of in vitro modeling,pharmaceutical development,and clinical regenerative medicine.
基金This work was supported by the National Natural Science Foundation of China[grant number 52075285]the Science and Technology Program of Guangzhou,China[grant number 201604040002]+1 种基金the Key-Area Research and Development Program of Guangdong Province,China[grant number 2020B090923003]the Key Research and Development Projects of People’s Liberation Army,China[grant number.BWS17J036].
文摘The ready-to-use,structure-supporting hydrogel bioink can shorten the time for ink preparation,ensure cell dispersion,and maintain the preset shape/microstructure without additional assistance during printing.Meanwhile,ink with high permeability might facilitate uniform cell growth in biological constructs,which is beneficial to homogeneous tissue repair.Unfortunately,current bioinks are hard to meet these requirements simultaneously in a simple way.Here,based on the fast dynamic crosslinking of aldehyde hyaluronic acid(AHA)/N-carboxymethyl chitosan(CMC)and the slow stable crosslinking of gelatin(GEL)/4-arm poly(ethylene glycol)succinimidyl glutarate(PEG-SG),we present a time-sharing structure-supporting(TSHSP)hydrogel bioink with high permeability,containing 1%AHA,0.75%CMC,1%GEL and 0.5%PEG-SG.The TSHSP hydrogel can facilitate printing with proper viscoelastic property and self-healing behavior.By crosslinking with 4%PEG-SG for only 3 min,the integrity of the cell-laden construct can last for 21 days due to the stable internal and external GEL/PEG-SG networks,and cells manifested long-term viability and spreading morphology.Nerve-like,muscle-like,and cartilage-like in vitro constructs exhibited homogeneous cell growth and remarkable biological specificities.This work provides not only a convenient and practical bioink for tissue engineering,targeted cell therapy,but also a new direction for hydrogel bioink development.
基金supported by Ministry of Education of Singapore,under Academic Research Fund Tier 1(Grant Number RG143/23).
文摘Scientific and technological advancements are rapidly transforming underground engineering,shifting from labor-intensive,time-consuming methods to automated,real-time systems.This timely and comprehensive review covers in-situ testing,intelligent monitoring,and geophysical testing methods,highlighting fundamental principles,testing apparatuses,data processing techniques,and engineering applications.The state-of-the-art summary emphasizes not only cutting-edge innovations for complex and harsh environments but also the transformative role of artificial intelligence and machine learning in data interpretations.The integration of big data and advanced algorithms is particularly impactful,enabling the identification,prediction,and mitigation of potential risks in underground projects.Key aspects of the discussion include detection capabilities,method integration,and data convergence of intelligent technologies to drive enhanced safety,operational efficiency,and predictive reliability.The review also examines future trends in intelligent technologies,emphasizing unified platforms that combine multiple methods,real-time data,and predictive analytics.These advancements are shaping the evolution of underground construction and maintenance,aiming for risk-free,high-efficiency underground engineering.
基金supported by the Energy Foundation(No.G-2203-33693).
文摘To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration method.We investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the future.The results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance rate.Differenceswere observed amongmachinery types,with low-power engine forklifts showing higher smoke levels.The NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively small.Engine rated net power had the most significant impact on NO_(x)emissions.Thus,NO_(x)emissions from construction machinery need further attention.Furthermore,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission limits.In the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.
基金sponsored by the National Key Research and Development Program of China(2021YFB3802000 and 2021YFB3802004)the National Natural Science Foundation of China(52172016).
文摘The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination of microbial technology and a rotary kiln process was employed to expedite the carbonation of steel slag for fixation from cement kiln flue gas.This approach resulted in a significant increase in the CO_(2)-fixation rate,with a CO_(2)-fixation ratio of approximately 10%achieved within 1 h and consistent performance across different seasons throughout the year.Investigation revealed that both the CO_(2)-fixation ratio and the particle fineness are pivotal for increasing the soundness and reactivity of steel slag.When the CO_(2)-fixation ratio exceeds 8%and the specific surface area is at least 300 m2∙kg−1,the soundness issue of steel slag can be effectively addressed,facilitating the safe utilization of steel slag.Residual microbes present in the carbonated steel slag powder act as nucleating sites,increasing the hydration rate of the silicate phases in Portland cement to form more hydration products.Microbial regulation results in the biogenic calcium carbonate having smaller crystal sizes,which facilitates the formation of monocarboaluminate to increase the strength of hardened cement paste.At the same CO_(2)-fixation ratio,microbial mineralized steel slag powder exhibits greater hydration activity than carbonated steel slag powder.With a CO_(2)-fixation ratio of 10%and a specific surface area of 600 m^(2)∙kg^(−1),replacing 30%of cement clinker with microbial mineralized steel slag powder yields an activity index of 87.7%.This study provides a sustainable solution for reducing carbon emissions and safely and efficiently utilizing steel slag in the construction materials sector,while expanding the application scope of microbial technology.
基金funded by the project of Guangdong Provincial Basic and Applied Basic Research Fund Committee(2022A1515240073)the Pearl River Talent Recruitment Program(2019CX01G338),Guangdong Province.
文摘Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.To contribute to a better understanding of the state of the art of smart techniques for engineering projects,this paper provides a comprehensive review of multi-criteria decision-making(MCDM)techniques,intelligent techniques,and their applications in CEM.First,a comprehensive framework detailing smart technologies for construction projects is developed.Next,the characteristics of CEM are summarized.A bibliometric review is then conducted to investigate the keywords,journals,and clusters related to the application of smart techniques in CEM during 2000-2022.Recent advancements in intelligent techniques are also discussed under the following six topics:①big data technology;②computer vision;③speech recognition;④natural language processing;⑤machine learning;and⑥knowledge representation,understanding,and reasoning.The applications of smart techniques are then illustrated via underground space exploitation.Finally,future research directions for the sustainable development of smart construction are highlighted.
基金grants from Administration of Traditional Chinese Medicine of Sichuan(A2016N48)National Natural Science Foundation of China(81171780)+4 种基金Foundation for Distinguished Young Scientists of Sichuan Province(2016JQ0020)Project sub topics of the National 863 Project(2015AA020303)Scientific research fund for outstanding young scholars of Sichuan University(2014SCU04A12)Sichuan province science and technology support plan(2015SZ0049)Science and technology support program of Sichuan Province(2015FZ0040).
文摘Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a serious problem. A potential solution to this problem is to fabricate skin constructs using biomaterial scaffolds with or without cells. Bioprinting is being applied to address the need for skin tissues suitable for transplantation, and can lead to the development of skin equivalents for wound healing therapy. Here, we summarize strategies of bioprinting and review current advances of bioprinting of skin constructs. There will be challenges on the way of 3D bioprinting for skin regeneration, but we still believe bioprinting will be potential skills for wounds healing in the foreseeable future.
基金financially supported by National Key R&D Program of China(2021YFB3500702)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04).
文摘With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.
基金National Key R&D Program of China(Nos.2023YFC3806900,2022YFE0141400)。
文摘The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have become a pivotal production tool in this context.Since the arm span of a single robot usually does not exceed 3 meters,it is not competent for producing large-scale building components.Accordingly,the extension of the robot,s working range is often achieved by external axes.Nevertheless,the coupling control of external axes and robots and their kinematic solution have become key challenges.The primary technical difficulties include customized construction robots,automatic solutions for external axes,fixed axis joints,and specific motion mode control.This paper proposes solutions to these difficulties,introduces the relevant basic concepts and algorithms in detail,and encapsulates these robotics principles and algorithm processes into the Grasshopper plug-in commonly used by architects to form the FURobot software platform.This platform effectively solves the above problems,lowers the threshold for architects,and improves production efficiency.The effectiveness of the algorithm and software in this paper is verified through simulation 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This work was supported by the National Natural Science Foundation of China,Fok Ying Tung Education foundation and the ScienceTechnology Foundation of Sichuan Province for Young Scholars.
文摘In this paper, the concretely both reflective and coreflective subconstructs of the construct CFTSof Chang fuzzy topological spaces are characterized and their relationship to such subconstructs of stratifiedfuzzy topological spaces is investigated. Properties of a particular such subconstruct of CFTS, the constructof weak fuzzy neighborhood spaces, are discussed in detail. And it is proved that there exists exactly c suchsubconstructs between the subconstruct of weakly induced spaces and CFTS.
文摘Our long-term objective is to develop a software toolbox for pre-embodiment design of complex and heterogeneous systems, such as cyber-physical systems. The novelty of this toolbox is that it uses system manifestation features(SMFs) for transdisciplinary modeling of these systems. The main challenges of implementation of the toolbox are functional design- and language-independent computational realization of the warehouses, and systematic development and management of the various evolving implements of SMFs(genotypes, phenotypes, and instances). Therefore, an information schema construct(ISC) based approach is proposed to create the schemata of the associated warehouse databases and the above-mentioned SMF implements. ISCs logically arrange the data contents of SMFs in a set of relational tables of varying semantics. In this article we present the ISCs necessary for creation of genotypes and phenotypes. They increase the efficiency of the database development process and make the data relationships transparent. Our follow-up research focuses on the elaboration of the SMF instances based system modeling methodology.
文摘Complementing our previous publications, this paper presents the information schema constructs （ISCs） that underpin the programming of specific system manifestation feature （SMF） orientated information management and composing system models. First, we briefly present （1） the general process of pre-embodiment design with SMFs, （2） the procedures of creating genotypes and phenotypes of SMFs, （3） the specific procedure of instantiation of phenotypes of SMFs, and （4） the procedure of system model management and processing. Then, the chunks of information needed for instantiation of phenotypes of SMFs are discussed, and the ISCs designed for instantiation presented. Afterwards, the information management aspects of system modeling are addressed. Methodologically, system modeling involves （1） placement of phenotypes of SMF in the modeling space, （2） combining them towards the desired architecture and operation, （3） assigning values to the parameters and checking the satisfac- tion of constraints, and （4） storing the system model in the SMFs-based warehouse database. The final objective of the reported research is to develop an SMFs-based toolbox to support modeling of cyber-physical systems （CPSs）.
基金Science and Technology Research Project of Chongqing Education Commission(Project No.:KJQN202401902)Chongqing Construction Science and Technology Plan Project(Project No.:Chinese Society For Urban Studies,2024:3-24)+1 种基金cientific Research Fund Project of Chongqing Institute of Engineering(Project No.:2022gcky01)College Student Innovation and Entrepreneurship Training Program Project of Chongqing Institute of Engineering(Project No.:CXCY2024018)。
文摘Taking modern indoor building construction as an example,this study analyzes the path planning and navigation of a smart plastering robot.It includes a basic introduction to smart plastering robots,an analysis of multi-sensor fusion localization algorithms for smart plastering robots,and an analysis of path planning and navigation functions for smart plastering robots.It is hoped that through this analysis,a reference is provided for the path planning and navigation design of such robots to meet their practical application needs.
基金supported by the National Nature Science Foundation of China(No.12172211)the National Key Research and Development Program of China(No.2019YFC1509800)。
文摘1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.
文摘Construction work is an important component of social development,and its safety management is crucial for the protection of employees’lives,the efficient development of enterprises,and the social harmony and stability.Therefore,this paper explores the risk identification,risk estimation,risk evaluation,and control strategies of construction sites.It analyzes the research progress,current issues that need optimization,and future development directions,aiming to provide insights for the development of risk evaluation in construction sites.
