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The energy saving and emissions reduction of the construction industry are crucial for China to achieve the “carbon peaking and carbon neutrality” goals. In order to promote the green development of the life cycle of the construction industry and improve the efficiency of emissions reduction. This paper examines the spatial-temporal distribution of life cycle carbon emissions in China’s construction industry (LCCECI) from 2004 to 2018. It uses the SBM-Malmquist total factor productivity (TFP) index to measure technological progress and establishes the spatial econometric model based on the STIRPAT model. The study investigates the driving factors of the LCCECI at the provincial and regional levels, aiming to provide suggestions for low-carbon development in the construction industry. The research results are as follows. ① The growth in the SBM-Malmquist TFP index of the construction industry distinctly curbs the LCCECI. ② Total population and urbanization level are not the primary driving factors for the LCCECI. The growth of per capita GDP significantly induces the LCCECI, while concurrently exhibiting a notable inhibitory effect on the LCCECI of neighboring regions. ③ The improvement of the SBM-Malmquist TFP index is conducive to the reduction of the LCCECI in the three major regions. The per capita GDP has the largest positive driving effect of the LCCECI in the eastern region, and the urbanization level the urbanization rate only significantly inhibits the growth of the LCCECI in the central region.

Cyberspace Mimic Defense (CMD) is a proactive defense theory proposed in recent years to deal with vulnerability and backdoor threats that are common in information systems. Different from moving target defense (MTD), CMD can obtain foundation by verifying multiple results from isolated, heterogeneous, and parallel running spaces, thus initiating a more targeted defensive action, such as scheduling and structure transformation. However, scheduling sequence control is a severe problem in this process, which needs to select a series of scheduling time and take into account security, efficiency, and robustness for variable attack situations. Inspired by the traffic and congestion control mechanism in computer networks, this paper proposed a sliding window-based scheduling sequence control method. By setting driver events to trigger the window “sliding,” the control parameters update and adapt to the current state accordingly. Then, considering internal resource constraints and external attack situations, a two-factor driver on variable period and exception threshold with their corresponding calculations are specified. Evaluations show that this method can maintain good performance under different scenarios, which proves to be an effective solution for scheduling sequence control in CMD.

Abstract We study an approximate coincidence point and a common fixed point problem for a hybrid pair of mappings with constraints in Menger PM-spaces, and obtain some new results. We derive interesting consequences of the main results by using the properties of a Menger–Hausdorff metric, and analogous results based on graphs instead of partial orders can be similarly formulated. Moreover, we construct two examples to reveal that the main results are valid, and show that the main results can be used to explore the existence of solutions to a system of nonlinear integral equations.

The bolted T-stub connection joining beam with column is being widely applied. To enhance the energy dissipation capacity of conventional T-stub connections, two rectangular plates are proposed to be inserted between the T-stub and column, so that the T-stub flange can yield both under tensile and compressive loads. This study put forward a mechanical model of a new T-stub connection with inserted plates and investigated important factors that could affect its mechanical behavior through experimental tests. Thirty specimens were designed with different configurations that differed according to the existence or absence of inserted plates, the fabrication method and the width of inserted plates. These configurations were tested under axial and cyclic loading conditions, and results showed that the proposal aiming to improve the energy dissipation capacity was feasible. The mechanical model presented coincided with the test observation and data. The advent of two inserted plates elevated the load bearing capacity, stiffness and ductility of connections under compression, whereas in tension the properties were not substantially enhanced. The welded T-stub connections outperformed those cut from standard section steel. The energy dissipated by connections with inserted plates was about 150% of that by traditional connections without inserted plates. Only within a reasonable range can the increment of plate width promote the energy dissipation capacity of T-stub connections. The optimum width of plates in terms of energy consumption accounted for around 31% of the overall width of connections.

Circular steel tube members with the absence of anticorrosive protection or coating failure are prone to uniform corrosion, which threatens the reliability and safety of members in the atmospheric environment. To fully study the mechanical behavior of uniformly corroded circular steel tubes, compression test and theoretical analysis were conducted, and two methods considering section reduction and material degradation, respectively, were adopted for the calculation of ultimate load carrying capacities of specimens. The results indicate that uniform corrosion did not change the failure modes of specimens, and all of them belonged to global buckling failure. The load carrying capacities and stiffness of specimens decreased with the increase of corrosion ratio, and the degree of reduction was greater than that of material degradation, showing a linear relationship with the corrosion rate. Under the same corrosion ratio, the specimens with larger eccentricity represented more obvious load carrying capacity and stiffness degradation. The load carrying capacities predicted by both methods were in good agreement with the test results and had a certain safety margin. The conservative degree of calculation results from three specifications followed a descending order of ANSI/AISC 360-16, GB 50017-2017, and EN 1993-1-1. Under the same corrosion ratio, the load carrying capacity variation of specimens between one-sided corrosion and two-sided corrosion was less than 3%.

Some new coupled coincidence point and coupled fixed point theorems are established in partially ordered metric-like spaces, which generalize many results in corresponding literatures. An example is given to support our main results. As an application, we discuss the existence of the solutions for a class of nonlinear integral equations.

Anti-washout underwater concrete (AWC) is widely used in nondrainage strengthening; however, there still exist some problems with it, such as high strength loss and poor interfacial bond in practical engineering application. Based on the study of self-stressed concrete (SSC), a research on the mix ratio for the C30 self-stressed anti-washout underwater concrete (SSAWC) was carried out in this paper in hope of solving the above problems, specifically, by adding an expansive agent to the AWC. The parameters, such as strength, fluidity, anti-dispersity, and expansibility, were picked as target indices in determination of the mix ratio. The orthogonal test design and range analysis were used to determine the reasonable mix ratio and study the influence of various parameters on the performance of SSAWC. The experimental program conducted includes a series of strength, fluidity, anti-dispersity, and expansibility tests on 18 groups of specimens. The results show that C30 SSAWC has an excellent performance using the optimal mix ratio. Compared with AWC, the expansibility and self-stress of the SSAWC can be easily observed, and the compressive strength ratio of the SSAWC casted in water to that casted in air is much bigger. This implies that SSAWC is applicable to the nondrainage strengthening.

In this work, the Cauchy initial value problem is discussed for a class of fractional impulsive differential equations with delay, and the criteria on existence and uniqueness are obtained. Finally, an example is also provided to illustrate the effectiveness of our main results.

We introduce the concepts of (H,ψ,Φ)-contraction and probabilistic (α,φ)-contraction mappings in generalized probabilistic metric spaces and prove some fixed point theorems for such two types of mappings in generalized probabilistic metric spaces. Our results generalize and extend many comparable results in existing literature. Some examples are also given to support our results. Finally, an application to the existence of solutions for a class of integral equations is presented by utilizing one of our main results.

This study focused on capturing the research landscape of past studies related to the effects of electronic books on young children ’s reading development from 1999 to 2022 through a bibliometric analysis. All 99 included bibliographic data were extracted from the Scopus database. The findings show an increasing trend in publications and citations over the last twenty years. The publications were distributed over six continents, namely North America, South America, Europe, Oceania, Africa, and Asia. The United States was the most productive country with the highest number of publications, h -index, and g -index. The foci of the research are (i) the important role digital device plays in children ’s book reading; (ii) strategies taken by families and teachers to support the emergent literacy skills based on e -book; (iii) cognition and language skills domains in e -book reading among preschoolers. The findings of this study help researchers to understand the current landscape of research on e -book reading among preschoolers and provide guidelines for researchers to understand the core issues. [ABSTRACT FROM AUTHOR]

We propose an Otto heat engine that undergoes processes involving a special class of feedback and analyze theoretically its response. We use stochastic thermodynamics to determine the performance characteristics of the heat engine and indicate the possibility that its maximum efficiency can surpass the Carnot value. The analytical expression for efficiency at maximum power, including the effects resulting from feedback, reduces to that previously derived based on an engine without feedback. [ABSTRACT FROM AUTHOR]

Grouted connections are commonly used in marine engineering, especially on oil platforms, cross-sea bridges, and offshore wind power turbines. The prediction methods for axial carrying capacity of grouted connections with shear keys and their application ranges in current codes were analyzed in this paper. The calculated results by using different codes were compared based on a practical grouted connection between steel piles and the jacket foundation of a wind turbine. The research team conducted axial compression tests on seven specimens, collected a wide range of experimental results to establish a database, and finally compared the standard calculation results with the experimental results. The study indicates that the axial strength of grouted connections predicted by different methods is distinct. The calculation formula of the British Health and Safety Executive (HSE, 2002) has obvious limitations; specifically, with increased shear keys, strength is overestimated, resulting in insecure design outcome of structures. The results calculated by the Norwegian Det Norske Veritas (DNV, 2013) are generally consistent with the experimental results, in which the reduction effect of multiple shear keys was considered. The prediction method of the American Petroleum Institute (API, 2007), which undervalues the bearing performance of connections, is excessively conservative. The method of the combined Norwegian and German Det Norske Veritas–Germanischer Lloyd (DNV-GL, 2016) has wider applicability and is safe, reliable, and economical. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the existence of a fixed point of a self-mapping T on a Menger PM-space under two constraint inequalities with respect to two partial orders under two kinds of contractive conditions and obtain some new fixed point results. We then present several useful consequences of our main results. We also give examples to show the validity of our main results. [ABSTRACT FROM AUTHOR]

The initial rotational stiffness of connections is important for the design of semirigid frames. However, most current studies on steel beam to concrete-filled steel tube column connections with bidirectional bolts are based on experimental tests, and theoretical analysis and numerical analysis are rarely reported. As a result, there is no suitable analytical model for calculating the initial stiffness of the connection. Based on the component method, this paper proposes an analytical model to predict the initial stiffness of the connection. It is considered that the connection rotation is mainly induced by deformations of the endplate in bending, column flange in bending, bolts in tension, and panel zone in shear. Moreover, the effects of the endplate in bidirectional bending and bolt pretension are taken into consideration. Then, the prediction results based on the proposed analytical model are compared with experimental results to verify its accuracy, and comparison results indicate that the proposed analytical model can predict the initial rotational stiffness of steel beam to concrete-filled steel tube column connection well. In addition, bolt diameter and endplate thickness are the most influential parameters that affect the initial stiffness of the connection. It also provides a way for such connections to be designed as rigid connections. Finally, the proposed analytical model can be applied with good precision in elastic analysis and serviceability calculations in the design of semirigid steel-concrete composite frames. It can be applied to four types of connections: stiffened extended endplate connections, nonstiffened extended endplate connections, flush endplate connections, and T-stub connections. The proposed analytical model saves substantial resources and workload in experiments and simulations. DOI: 10.1061/(ASCE)ST.1943-541X.0002187. ' 2018 American Society of Civil Engineers. [ABSTRACT FROM AUTHOR]

A mechanical model for shear bearing capacity of buckling restrained steel plate shear walls was developed based on their stress distribution. It was considered that the shear bearing capacity was provided by the effective shear field of the panel and edge support members. A uniform formula for shear bearing capacity of buckling restrained steel plate shear walls was developed and validated by comparing with experimental and numerical results, and the specification. Further analysis shows that in range of practical aspect ratios of 0.5-2.0, the effective shear area varies in 20%-55% of the whole panel of the shear walls connected with only beams, and the bearing capacity is reduced by 10%-52% compared with that of the walls connected with both beams and columns. Its safety margin is lower than that of the walls connected with beams and columns and the walls with added side columns because of tearing at the corners in advance. The feasibility of adding columns at both vertical edges of the walls connected only with beams was illustrated by an example. The requirement of side-column section areas was proposed to ensure an effective shear stress field in whole panel. [ABSTRACT FROM AUTHOR]

The notion of coincidence point and common fixed point were extended in generalized partially ordered fuzzy metric spaces. Under some conditions, some coincidence point and common fixed point theorems were established in generalized partially fuzzy metric spaces using weakly compatible mappings. These results improve some theorems in corresponding literature. [ABSTRACT FROM AUTHOR]

In this work, we introduce the notion of Menger probabilistic metric type space, on the other hand, we introduce a more general class of auxiliary functions in contractivity condition, following that, we obtain some multipled common fixed point theorems for a pair of mappings T : . . .⇢X and A : X ⇢ X. As an application, we give out an example to demonstrate the validity of the obtained results. [ABSTRACT FROM AUTHOR]

In this paper, we prove some new fixed point theorems for multi-valued mappings under new contractions by proposing a new class of functions. The results of this paper improve several results in the literatures. And we extend the results into metric-like spaces, which expand the application range of the results. [ABSTRACT FROM AUTHOR]

In this paper, we introduced the notion of α-ψ-type contractive mapping in PGM-spaces and established some new fixed point theorems in complete PGM-spaces. Finally, an example is given to support our main results. [ABSTRACT FROM AUTHOR]

In this paper, by using random fixed point index theory, some new boundary conditions based on strictly convex or strictly concave functions are established and some new theorems for the solutions of a class of random semi-closed 1-set-contractive operator equations A(ω, x) = µx are obtained, which extend and generalize some corresponding results of Wang [S. Wang, Fixed Point Theory Appl., 2011 (2011), 7 pages]. Finally, an application to a class of random nonlinear integral equations is given to illustrate the usability of the obtained results. [ABSTRACT FROM AUTHOR]

In this paper, utilizing the concepts of weakly biased mappings and occasionally weakly biased mappings for a pair of self-mappings in Menger PM-spaces, some new common fixed point theorems under contractive conditions are obtained. Some examples are also given to exemplify our main results. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the concepts of cyclic weakly (ψ, ...)-contractive mappings and cyclic weakly (C, ψ, φ)-contractive mappings, and prove some fixed point theorems for such two types of mappings in complete partially ordered Menger PM-spaces. Some new results are obtained, which extend and generalize some fixed point results in metric and probabilistic metric spaces. Some examples are given to support our results. [ABSTRACT FROM AUTHOR]

In this paper, a new concept of the common property (E.A) for two hybrid pairs of mappings is introduced in Menger PM-spaces. Utilizing this concept, some common fixed point theorems, which shed some new light on the study of fixed point results for hybrid pairs in Menger PM-spaces, are obtained under strict contractive conditions. The corresponding results in metric spaces which generalize many known results are also obtained. Finally, an example is also given to exemplify our main results. [ABSTRACT FROM AUTHOR]

We establish a quantum Otto engine (QOE) of a two-level atom, which is confined in a one-dimensional (ID) harmonic trap and is coupled to single-mode radiation fields. Besides two adiabatic processes, the QOE cycle consists of two isochoric processes, along one of which the two-level atom as the working substance interacts with a single-mode radiation field. Based on the semigroup approach, we derive the time for completing any adiabatic process and then present a performance analysis of the heat engine model. Furthermore, we generalize the results to the performance optimization for a QOE of a single two-level atom trapped in a 1D power-law potential. Our result shows that the efficiency at maximum power output is dependent on the trap exponent 9 but is independent of the energy spectrum index &sgr;. [ABSTRACT FROM AUTHOR]

In this paper, we establish some fixed point theorems for non-self mappings, which solve the problem 1 in [1], satisfying special contractive conditions in complete metric spaces. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new type of common fixed point for three mappings in Gb-complete Gb-metric space. On the other hand, we prove that the theory is also established in G-metric space and several corollaries and examples are listed. [ABSTRACT FROM AUTHOR]

In this paper, we study the mapping satisfying mixed g-monotone property in partially ordered complete Menger probabilistic G-metric spaces. By weakening the notion of Ψ, we prove some new coupled coincidence point theorems and coupled common fixed point theorems. Finally, we provide an example to illustrate our results. [ABSTRACT FROM AUTHOR]

In this paper, we, motivated by Mihet [2], give the concept of two nonlinear contractions ((φ, ε-λ)-contraction and (f, bn)-contraction) in KM-fuzzy metric spaces, and obtained some fixed point theorems. We answer the open question posed by Mihet in [2, open question 2]. Finally, an example can be used to be exemplify our results. [ABSTRACT FROM AUTHOR]

We study the efficiency at maximum power, &eegr;m, of irreversible quantum Camot engines (QCEs) that perform finite-time cycles between a hot and a cold reservoir at temperatures Th and Tc., respectively. For QCEs in the reversible limit (long cycle period, zero dissipation), &eegr;m becomes identical to the Carnot efficiency &eegr;c = 1 -- Tc/Th- For QCE cycles in which nonadiabatic dissipation and the time spent on two adiabais are included, the efficiency &eegr;m at maximum power output is bounded from above by &eegr;c/(2 -- &eegr;c) and from below by &eegr;c/2. In the case of symmetric dissipation, the Curzon-Ahlbom efficiency &eegr;CA = 1 - √Tc/Th is recovered under the condition that the time allocation between the adiabais and the contact time with the reservoir satisfy a certain relation. [ABSTRACT FROM AUTHOR]