Complex Construction Process Research Articles

Visionary constructs: revolutionizing students internships through BIM and extended reality synergy

ABSTRACT This study investigates the integration of Building Information Modeling (BIM) and Extended Reality (XR) technologies in construction education, focusing on their application in internship programs. Traditional internships often face limitations such as restricted exposure to complex scenarios and geographical constraints. To address these challenges, this research examines how BIM-XR technologies can bridge the gap between theoretical knowledge and practical application in the Architecture, Engineering, and Construction (AEC) disciplines. A mixed-methods approach was employed, combining qualitative data from interviews with students, educators, and industry professionals alongside quantitative survey data. This comprehensive methodology enabled an in-depth assessment of BIM-XR's impact on student learning outcomes and operational efficiency. The findings revealed that BIM-XR integration significantly enhances educational experiences by providing immersive simulations that help students visualize complex construction processes. This leads to better preparedness for real-world challenges, increased engagement, and more effective internships. Additionally, BIM-XR offers practical benefits for industry practices, such as improved project planning, real-time decision-making, and enhanced stakeholder collaboration. However, the study also highlights challenges, including the steep learning curve, limited access to necessary technologies, and high implementation costs. These limitations point to the need for comprehensive training programs, affordable technology options, and institutional support to ensure broader adoption. Looking ahead, the study suggests that further integration of BIM-XR with emerging technologies like Artificial Intelligence (AI), Machine Learning (ML), and the Internet of Things (IoT) could further enhance educational outcomes and industry practices.

Revealing the coupled evolution process of construction risks in mega hydropower engineering through textual semantics

Mega hydropower engineering (MHE) involves complex construction processes, harsh environments, and highly mobile personnel, equipment, and other resources, resulting in a high incidence of construction risks and significant difficulties in safety control. Previous studies extensively explored the identification and governance of risks in MHE. However, these studies did not adequately utilize accident report case texts, and the coupled evolutionary law of construction risks remains unclear. To address this gap, this study developed a Bert-based Global Pointer Network for Named Entity-Relation Joint Extraction (Bert-GPLinker) to extract risk factors and their relationships. Second, the extracted risk factors and their relationships were employed to construct a knowledge graph, integrating text matching and path inference algorithms to propose a coupled evolutionary path reasoning method for construction risks. Finally, the coupled interactions among the risk factors were considered, and the interaction matrix principle was utilized to quantitatively assess the importance of each risk factor in the knowledge graph. The results showed that (1) the F1 value of Bert-GPLinker on the self-built dataset was 91.90%, indicating better model performance; (2) the coupled evolutionary reasoning system can quickly deduce the evolutionary path with the highest probability of any risk node and the types of accidents that may result; and (3) among the top 25 risk factors in terms of importance, those in the management system category accounted for 52%, with higher importance mainly concentrated in inspection, supervision, and training.

Modular stochastic configuration network with attention mechanism for soft measurement of water quality parameters in wastewater treatment processes

Due to the complex and multi-distributed nature of wastewater treatment process data, stochastic configuration networks (SCNs) face difficulties such as large network structure and complex construction process when dealing with data modeling tasks. To address these challenges, this paper proposes a modular stochastic configuration network with attention mechanism, which integrates the advantages of modular partitioning, attention mechanism, and SCN. The model employs a fuzzy mean clustering strategy to simplify and decompose the complex multi-case and multi-distribution nonlinear modeling task, thereby reducing the modeling complexity of a single model. Furthermore, the model utilizes a stochastic configuration algorithm to learn the subtasks and construct corresponding sub-networks. The output weights are then assigned to each sub-network based on the attention mechanism to obtain the model’s final output. The validity of the proposed method is validated through two benchmark experiments. Then the model is applied to measure effluent ammonia nitrogen. The results indicate that compared with the classical randomized and modularized network models, the proposed model exhibits certain advantages in terms of learning accuracy and generalization performance.

Research on Construction Risk Assessment of Long-Span Cantilever Casting Concrete Arch Bridges Based on Triangular Fuzzy Theory and Bayesian Networks

Considering the complex construction processes involved, there are significant risks during the construction of long-span cantilever casting arch bridges. In this study, a risk assessment method for the construction process of cantilever casting concrete arch bridges was developed. The compositional elements and characteristics of safety risks in the construction of cantilever casting concrete arch bridges were clarified, and a safety risk source list that includes seven major risk sources and thirty-three minor risk sources was formed. Then, a Bayesian model for the risk analysis of cantilever casting concrete arch bridge construction was established, and a method was proposed to determine the prior and posterior probabilities of the Bayesian network using triangular fuzzy numbers. This method fully utilizes the experience of experts while avoiding the subjectivity of expert opinions. A cantilever casting concrete open spandrel arch bridge (Bridge A) with a total span length of 287 m was taken as an example, and a safety risk assessment was conducted during its construction process. The calculation results show that the construction safety risk level of Bridge A was level III. This engineering application verified the feasibility of determining key node parameters of the Bayesian network using triangular fuzzy numbers.

Persistent autonomous molecular motion of DNA walker along a single-molecule nano-track for intracellular MicroRNA imaging

While the intracellular imaging of miRNA biomarkers is of significant importance for the diagnosis and treatment of human cancers, DNA assembled nanoprobe has recently attracted considerable attention for imaging intracellular biomolecules. However, the complex construction process, intrinsic vulnerability to nuclease degradation and the limited signal transduction efficiency hamper its widespread application. In this contribution, based on persistent autonomous molecular motion of DNAzyme walker along a nano-substrate track, a DNA nanosphere probe (PNLD) is developed for the sensitive intracellular miR-21 imaging. Specifically, DNA nanosphere (called PN, single-molecule nano-track) is assembled from only one palindromic substrate, into which the locking strand-silenced DNAzymes (LD) are installed in a controlled manner. PNLD (made of PN and LD) can protect all DNA components against nuclease attack and maintain its structural integrity in serum solution over 24 h. Upon the activation by target miRNA, DNAzyme walker can move on the substrate scattered within PNLD (or on the surface) and between different PNLD objects and cleave many DNA substrates, generating an amplified signal. As a result, miR-21 can be detected down to 6.83 pM without the detectable interference from co-existing nontarget miRNAs. Moreover, PNLD system can accurately screen the different expression levels of miR-21 within the same type of cells and different types of cells, which is consistent with gold standard polymerase chain reaction (PCR) assay. Via changing the target recognition sequence, the PNLD system can be suitable for the intracellular imaging of miR-155, exhibiting the desirable universality. In addition, the DNAzyme walker-based PNLD system can be used to distinguish cancer cells from healthy cells, implying the potential application in cancer diagnosis and prognosis.

Seismic performance assessment of a base-isolated hospital building subjected to February 6, 2023, Kahramanmaraş, Türkiye earthquakes (Mw 7.7 Pazarcık and Mw 7.6 Elbistan) and seismic fragility analysis considering different construction stages

The construction period of large structures such as hospitals can be prolonged due to complex construction processes. The behavior of frictional pendulum systems (FPSs) is strongly influenced by the seismic weight of the superstructure and the corresponding coefficient of friction. Therefore, the effects of the isolator behavior, which varies throughout the construction stages (CSs), on structural responses should be evaluated. Existing literature lacks adequate investigation into the behavior of isolated structures subjected to earthquakes during CSs. To address this gap, this paper investigates the structural performance of a base-isolated hospital building equipped with FPSs that experienced residual displacements during the February 6, 2023, Kahramanmaraş, Türkiye earthquakes (Mw 7.7 Pazarcık and Mw 7.6 Elbistan). At the time of the earthquakes, the building was still under construction (65–70 % complete). In addition to the hospital building under consideration, there were three more hospital buildings equipped with FPSs under construction during the 2023 Kahramanmaraş-Türkiye earthquakes in Türkiye. The seismic behavior and residual displacements of the structure during this CS were evaluated and numeric results were validated with real data measured in the field. Moreover, fragility analyses were performed for different CSs of the hospital building to reveal the probabilities of damage for base-isolated buildings exposed to earthquakes at various CSs. For fragility assessment, damage states (slight, moderate, extensive, collapse) were defined and four damage measures were chosen. Thus, the extent to which construction stages affected which types of damage was determined. A total of 1296 nonlinear time-history analysis were conducted to obtain fragility curves for all CSs and damage measures considering lower bound, nominal, and upper bound values of isolators. Selected isolated hospital building showed vulnerability in maximum top floor acceleration (MTFA) and maximum isolator displacement (MID) damage measures, but resilience in maximum roof drift ratio (MRDR) and maximum inter-story drift ratio (MIDR) damage measures. For the design basis earthquake (DBE) level, the probability of reaching the extensive damage state was 5.25 % for the MID, 11.39 % for MTFA, and 0 % for MIDR and MRDR. Similarly, for the maximum considered earthquake (MCE) level, these values were determined as 34.09 % for MID, 43.42 % for MTFA, and 0 % for MIDR and MRDR. The analysis revealed that while the probability of damage to the base isolation system was not related to CSs, residual displacements increased as construction progressed. Collapse thresholds for MIDR and MRDR demand exceptionally severe seismic events. As construction progresses, probabilities of exceeding damage states increase for MIDR and MRDR, indicating heightened vulnerability.

Finding Natural, Dense, and Stable Frustrated Lewis Pairs on Wurtzite Crystal Surfaces for Small‐Molecule Activation

AbstractThe surface frustrated Lewis pairs (SFLPs) open up new opportunities for substituting noble metals in the activation and conversion of stable molecules. However, the applications of SFLPs on a larger scale are impeded by the complex construction process, low surface density, and sensitivity to the reaction environment. Herein, wurtzite‐structured crystals such as GaN, ZnO, and AlP are found for developing natural, dense, and stable SFLPs. It is revealed that the SFLPs can naturally exist on the (100) and (110) surfaces of wurtzite‐structured crystals. All the surface cations and anions serve as the Lewis acid and Lewis base in SFLPs, respectively, contributing to the surface density of SFLPs as high as 7.26×1014 cm−2. Ab initio molecular dynamics simulations indicate that the SFLPs can keep stable under high temperatures and the reaction atmospheres of CO and H2O. Moreover, outstanding performance for activating the given small molecules is achieved on these natural SFLPs, which originates from the optimal orbital overlap between SFLPs and small molecules. Overall, these findings not only provide a simple method to obtain dense and stable SFLPs but also unfold the nature of SFLPs toward the facile activation of small molecules.

Finding Natural, Dense, and Stable Frustrated Lewis Pairs on Wurtzite Crystal Surfaces for Small-Molecule Activation.

The surface frustrated Lewis pairs (SFLPs) open up new opportunities for substituting noble metals in the activation and conversion of stable molecules. However, the applications of SFLPs on a larger scale are impeded by the complex construction process, low surface density, and sensitivity to the reaction environment. Herein, wurtzite-structured crystals such as GaN, ZnO, and AlP are found for developing natural, dense, and stable SFLPs. It is revealed that the SFLPs can naturally exist on the (100) and (110) surfaces of wurtzite-structured crystals. All the surface cations and anions serve as the Lewis acid and Lewis base in SFLPs, respectively, contributing to the surface density of SFLPs as high as 7.26×1014 cm-2. Ab initio molecular dynamics simulations indicate that the SFLPs can keep stable under high temperatures and the reaction atmospheres of CO and H2O. Moreover, outstanding performance for activating the given small molecules is achieved on these natural SFLPs, which originates from the optimal orbital overlap between SFLPs and small molecules. Overall, these findings not only provide a simple method to obtain dense and stable SFLPs but also unfold the nature of SFLPs toward the facile activation of small molecules.

大中小学思政课教师队伍一体化建设的意义、阻碍与路径研究

Teachers of ideological and political courses are the main implementers of ideological and political teaching and the key to running ideological and political courses well. Promoting the integrated construction of the teaching team of ideological and political courses in primary, secondary, and tertiary schools has important value and significance, which helps to achieve the unity of the overall and hierarchical goals of ideological and political education in primary, secondary, and tertiary schools, the unity of the similarities and differences in teaching content, and the unity of the stages and connections in educational effects. However, achieving the integration of ideological and political education teachers in primary, secondary, and tertiary schools requires a long-term and complex construction process. Currently, there are still many constraints such as varying levels of emphasis on the construction of ideological and political education teachers in different stages of primary, secondary, and tertiary education, insufficient effective communication and interaction among teachers, and uneven teacher abilities and qualities. It is necessary to find a practical path to optimize the ideological and political education teacher team and achieve the integration of ideological and political education teachers in primary, secondary, and tertiary education, Complete the fundamental task of cultivating virtue and talent.

Excavation method optimization and mechanical responses investigating of a shallow buried super large section tunnels: a case study in Zhejiang

The construction of super large section (SLS) shallow buried tunnels involves challenges related to their large span, high flat rate, and complex construction process. Selecting an appropriate excavation method is crucial for ensuring stability, controlling costs, and managing the construction timeline. This study focuses on the selection of excavation methods and the mechanical responses of SLS tunnels in different types of surrounding rock. The research is based on the Yangjiashan tunnel project in Zhejiang Province, China, which is a four-line highway tunnel with a span of 21.3 m. Three sequential excavation methods were proposed and simulated using the three-dimensional finite difference method: the “upper first and lower later” side drift (SD) method, the central diaphragm method, and the top heading and bench (HB) method. The mechanical response characteristics of tunnel construction under these methods were investigated, including rock deformation, rock pressure, and the internal forces acting on the primary support. By comparing the performance of the three construction methods in rock masses of Grades III to V, the study aimed to determine the optimal construction method for SLS tunnels considering factors such as safety, cost, and schedule. Field tests were conducted to evaluate the effectiveness of the optimized construction scheme. The results of the field monitoring indicated that the “upper first and lower later” SD method in Grade V rock mass and the HB method in Grade III to IV rock mass are feasible and cost-effective under certain conditions. The research findings provide valuable insights for the design and construction of SLS tunnels in complex conditions, serving as a reference for engineers and project managers.

Investigating the Influence of the Improved Multibody Rope Approach on the Structural Behavior of Dakar Mosque Gridshell Structure

Gridshell structures are characterized by an impressive strength-to-weight ratio, allowing their application in large-span roofing structures. However, their complex construction process and maintenance limited their widespread application. In recent years, the development of parametric and computational design tools has rekindled interest in this type of structure. Among these techniques, the Multibody Rope Approach (MRA) is a form-finding method based on the dynamic equilibrium of a system of masses (nodes) connected by ropes, which allows optimizing the structural shape starting from the dual geometry of the funicular network. To optimize the construction process, an improved version of the MRA, i-MRA, has been recently developed by the authors with the goal of uniforming the size of the structural components. To investigate the impact of the i-MRA method on the structural behavior of gridshell structures, the practical case of the design of a mosque roof is here analyzed. The comparison is carried out in terms of structural performance with respect to permanent and equivalent quasi-static loads. In addition, free-vibration natural-frequency shift is obtained by performing linear modal analysis. Finally, the global behavior with respect to buckling and elastic instability is assessed solving the relevant eigenvalue problem. The results demonstrate that for the roofing of the Dakar mosque, the structural configuration obtained through i-MRA is superior in terms of both construction efficiency and structural performance. The achieved shape exhibits a more uniform distribution of stresses induced by the applied loads together with very limited structural element typologies.

Уникальный и утерянный мраморный иконостас Пермского Спасо-Преображенского кафедрального собора

The Spaso-Preobrazhensky Cathedral in Perm, over 200 years old, underwent a complex construction process marked by numerous difficulties and prolonged completion. There were several reconstructions of the cathedral, expansions, and the addition of side chapels. Initially, the cathedral was divided into two churches – a summer church and a winter church. The summer church housed a magnificent Baroque wooden iconostasis, transported from the Pyskorsky stavropegial monastery. It has survived unaltered. The winter church (dedicated to St. Stefan) featured another iconostasis made of marble. It was dismantled in 1931, when the cathedral was repurposed as the Perm Art Gallery. The internal reconstruction necessary to accommodate the art museum was made by architect N. A. Shvariov. A few pre-revolutionary publications described very briefly what the marble iconostasis looked like. It is maintained that the iconostasis was made at the Gornoshchitskiy Marble factory by the order of Vice-Governor Bornovolokov, with the icons placed in it. Painted by the artists of the Imperial Academy of Arts, the icons were given to the temple by Alexander Stroganov. There are no more details about who was the author of the iconostasis, of what kind of marble and at what time it was made, and how it was delivered to Perm. The study aims to analyze the history of the marble iconostasis, introduce the surname of the artisan, show and justify its uniqueness. Most of the documents presented in the publication, including photographs, are introduced into scholarly circulation for the first time.

A Three-Stage Dynamic Risk Model for Metro Shield Tunnel Construction

The complex construction process of the metro shield method often leads to safety accidents. The various construction stages of shield tunnel construction comprise different construction activities and are accompanied by different safety risk factors. However, traditional risk assessment often evaluates the risk factors as a whole before shield tunnel construction and does not evaluate the risk factors dynamically by construction stages and by construction activities. To fill this gap, this paper aims to construct a dynamic Bayesian-based safety risk assessment model for shield tunnel construction from the perspective of changing construction stages and activities. First, safety risk factors were identified using the work breakdown structure-risk breakdown structure (WBS-RBS) method. Then, a three-stage dynamic assessment model of safety risks was constructed to depict the shield launch, shield tunnel, and shield reach. The dynamic Bayesian network (DBN) was improved to address the model with triangular fuzzy numbers and the leaky noisy-or-gate extension model. Finally, a case study was conducted. The model proposed in this paper is able to reveal the dynamic evolution of safety risks triggered by different construction activities. It offers a new simulated model for the prevention of safety accidents in the construction of metro shields.

Development of ultra-light foamed insulation materials and interfacial bond behavior with fiber-reinforced alkali-activated composites

Due to the complex construction process, short service life and serious environmental pollution, the traditional insulation engineering and formwork engineering have caused great challenges and obstacles to the realization of the " dual carbon " goal. This study developed a new green external insulation system that integrates insulation and formwork based on alkali activation technology. The preparation technology of ultra-light foam insulation material (ULFIM) and the interface design method between ULFIM and fiber reinforced alkali-activated composite material (FRAC) were proposed. The effects of rice husk ash (RHA) and polyethylene (PE) fiber content on the dry density, thermal conductivity, compressive strength, volumetric water absorption, and pore structure parameters of ULFIM were studied. The effects of groove width, groove depth, groove spacing, and groove density on the interfacial bond behavior of FRAC-ULFIM were discussed. The microstructure of ULFIM and the interface transition zone morphology of FRAC-ULFIM and FRAC-extruded polystyrene (XPS) were observed using scanning electron microscopy (SEM), and the mechanism of influencing factors on the corresponding indicators were revealed. The results showed that adding an appropriate amount of RHA and PE fiber had a significant positive effect on improving the performance of ULFIM. In the past, the optimal dry density and thermal conductivity of ULFIM were only 191.5 kg/m3 and 0.0494 W/(m·K), respectively, and the compressive strength at 7 d could be as high as 0.49 MPa. In addition, interface shear performance test results have shown that the "bridging effect" of PE fiber can effectively improve the shear strength and ductility of FRAC-ULFIM, which was 23.7% higher than the interface shear strength of FRAC-XPS under the same conditions. The groove treatment increased the interfacial shear strength of FRAC-ULFIM from 74.59 kPa to 266.37 kPa, with a maximum increase rate of 257.11%. The proposed new green external insulation system has significant potential application value.

Experimental and Design Parametric Study of a Novel Grouted Square Steel Tube Upper Chord–Concrete Composite Floor

A novel composite floor consisting of an upper chord of a grouted square steel tube truss and a lower chord of a reinforced concrete slab is proposed to address existing problems with precast composite floors, such as a complex construction process, high cost, significant resource consumption, and severe environmental pollution. Sixteen-point loading tests were carried out on five simply supported one-way slabs to simulate the stress state of the floor under a uniform load and to investigate the stiffness, cracking moment, load-carrying capacity, and failure mode of the composite floor system. The results showed that the composite floor system exhibited ductile failure, with cracks uniformly distributed at the bottom of the slab; additionally, the grouted steel tube did not experience uplift or out-of-plane buckling, and the truss welds did not fracture, indicating that the composite floor system still had further deformation capacity and load-carrying capacity with satisfactory stress conditions. After unloading, the residual deformation of the composite floor accounted for 28% to 36% of the maximum deflection, demonstrating good deformation recovery ability. The bottom slab thickness and truss height are key parameters that influence the new composite floor, and increasing the two parameters enhances the cracking load, deformation resistance, and flexural capacity of the composite floor, with a significant improvement achieved by increasing the truss height. The floor slab should have a minimum thickness of 60 mm, as required by China’s Code for Design of Concrete Structures, and the truss height-to-span ratio should be 1:30, which meets the deformation and load-carrying requirements of the floor and conforms to the design concept of green buildings.

Integrated composite wall with geopolymer permanent insulation formwork: Interface bonding behavior and mechanism

Traditional external insulation engineering and formwork engineering in buildings are unable to meet the development needs of the construction industry under the current situation due to their complex construction processes, high environmental pollution, and insulation layers is prone to fire, peeling, and other diseases. Therefore, improving the technology of building external insulation engineering and formwork engineering scientifically and economically has become an urgent practical problem to be solved. This study developed an integrated composite wall with geopolymer insulation formwork based on alkali activation technology. The interface bonding performance between alkali-activated mortar (AAM) and building insulation materials (BIM), as well as between AAM and the post-cast normal concrete (NC) were examined by push-out test and single shear test, respectively. Among them, BIM includesd alkali-activated insulation materials (AAI) and traditional extruded polystyrene foam (XPS). Studied the enhancement effect and mechanism of interface treatment methods on two types of interfaces. The simplified models were proposed for the shear strength of AAM-NC interfaces with grooved treatment and crushed stone studs. The results showed that the interfacial bond strength of AAM-AAI was better than that of AAM-XPS, which was due to the more compact interface transition zone of AAM-AAI. The grooved treatment had a positive improvement effect on the shear strength of AAM-AAI and AAM-NC interfaces, increasing by 16.59%∼167.32% and 21.03%∼42.06%, respectively. Adding crushed stone studs and installing connectors can improve the bonding performance of AAM-NC interface by 19.63%∼42.99%. In addition, the proposed simplified models have high consistency between the predicted results and test results, which can provide good reference value for engineering design.

Research on Risk Evaluation Index System and Model of Power Grid Construction Project

Power grid engineering projects mainly refer to the power grid infrastructure and technical transformation projects, such projects have the characteristics of huge investment amount, complex construction process, long cycle and many risk factors. The planning, construction and operation process are affected and restricted by many factors, and the consequences of risks are relatively serious. Firstly, this paper analyzes the risk theory of power grid construction project from the aspects of related concepts, project implementation process, risk assessment, risk prevention, etc. Secondly, the risk evaluation index system of power grid construction projects is constructed from the aspects of risk identification theory, index selection principle and design process. Thirdly, based on the analysis of evaluation methods, the relative evaluation models are compared, selected and improved, and the risk evaluation model of power grid construction projects is constructed. Finally, it put forward the grid construction project risk management measures, including the development of risk management plan, risk avoidance, risk control, risk transfer, unique risk prevention, risk monitoring and other risk prevention strategies.

Fatigue performance of composite trough-girders with corrugated-steel-webs

A new composite trough-girder with corrugated-steel-webs (CTG-CSWs) is proposed to solve the problems of ordinary trough-girders: complex construction process, easy cracking at the intersection of concrete web and bottom plate, and poor mechanical performance. Also, the self-weight is reduced. First, this study experimentally investigated the flexural fatigue performance of a CTG-CSWs. Based on the compressive strain changes of the top concrete flange and mid-span deflection, the influence of fatigue load on the static mechanical properties of the girder was studied. Correspondingly, the fatigue performance was characterized. Furthermore, numerical studies were performed using finite element model. Parametric study was conducted by equivalent structural stress method. Experimental results showed the CTG-CSWs has similar degradation process of fatigue mechanical properties as that of ordinary reinforced concrete beams. The mid-span deflection and compressive strain of the top concrete flange increased obviously in the early stage of the fatigue test, and then increased slowly around an approximately straight line. In the whole process, the test beam was in the stage of slow connection and expansion of internal microcracks and further developed into micro-fracture, indicating good fatigue performance. Numerical studies verified the insensitivity of equivalent structural stress method to mesh size and element type. Also, it showed significant stress concentration existed at the connection between the corner of the corrugated web and lower flange plate. In practical application, it recommends determining a reasonable corner radius as required, and applying a turning angle of 50° to obtain the best fatigue performance of the whole weld.

Life cycle carbon emission assessment of large-span steel structures: A case study

Buildings take up a significant part of global carbon emissions and are a major contributor to the climate crisis. Large-span steel structures usually consume more materials, need more complex construction processes, and thus have a larger environmental impact. This study presents a comparative analysis of the life cycle carbon emissions of three typical large-span steel structures, i.e., a cable dome, a reticulated shell, and a suspendome, based on a design case. A tiered hybrid method using the process-based life cycle assessment for the processes with emission factors and using input–output-based life cycle assessment for the processes without emission factors is proposed to assess the life cycle carbon emissions. Comparisons on the carbon emissions of the three structures reveal that the cable dome is the best of the three, having the lowest steel consumption and the lowest carbon emissions. Although the component production phase appears to contribute most of the total emissions, the construction phase is also of considerable importance in alleviating the present emission pressure, especially for the cable dome and suspendome. Further analysis shows that carbon emissions of large-span steel structures are not simply linearly related to steel consumption and need to be considered as a separate design objective. This study provides a useful reference for life cycle carbon emission assessment and low-carbon design of large-span steel structures.

An electrostatic force-independent dephosphorylation-driven chemiluminescent biosensor for sensitive and rapid detection of poly(ADP-ribose) polymerase-1 in human breast tissues

Poly (ADP-ribose) polymerase-1 (PARP-1) is a multi-domain nuclear enzyme that mediates gene transcription and DNA repair. Accurate detection of PARP-1 is essential to clinical diagnostic. However, conventional PARP-1 assays rely on electrostatic force with the involvement of lengthy and complex construction processes and false positive. Herein, we construct an ultrasensitive chemiluminescent biosensor for rapid detection of PARP-1 in human breast tissues by integrating PARP-1-directed hyperbranched poly(ADP-ribose) (PAR) formation with alkaline phosphatase (ALP)-3-(2′-spiroadamantyl)-4-methoxy-4- (3′’-phosphoryloxyphenyl)-1,2-dioxetane (AMPDD)-mediated chemiluminescence system. Upon activation by dsDNA, PARP-1 cleaves nicotinamide adenine dinucleotide (NAD+), initiating the repeated polymerization of biotinylated ADP-ribose to form the dsDNA- PAR-biotin complex. The subsequent assembly of dsDNA-PAR-biotin complexes onto AuNPs through Au-S covalent bond results in the construction of the AuNPs-dsDNA-biotin nanostructure. AuNPs-dsDNA-biotin nanostructure subsequently captures SA-ALP to form the AuNPs-dsDNA-ALP nanostructure. After centrifugation and separation, the AuNPs-dsDNA-ALP nanostructure initiates the dephosphorylation of AMPPD to produce a high chemiluminescent signal. In this assay, only PARP-1 activated by dsDNA can cleave NAD+, efficiently eliminating background signal. The introduction of frozen method greatly shortens the assay time. Benefiting from high precision of the PARP-1-catalyzed NAD+ cleavage, high efficiency of biotinylated ADP-ribose polymerization reaction, and high signal-to-noise ratio of ALP-AMPPD chemiluminescence system, this biosensor can rapidly and sensitively detect PARP-1 with a detection limit of 2.94 × 10−7 U/μL, accurately screen PARP-1 inhibitors, and quantify PARP-1 at single-cell level. Most importantly, it can differentiate PARP-1 expression between breast cancer patient tissues and healthy person tissues, with promising applications in clinical diagnosis and biomedical research.