Yu Han, Yanqiu Xia, Xin Chen, Liang Sun, Dongyu Liu and Xiangyu Ge
The purpose of this study is to improve the corrosion resistance of the transmission towers by Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La…
Abstract
Purpose
The purpose of this study is to improve the corrosion resistance of the transmission towers by Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La) and cerium (Ce) (denoted as Zn-Al-Mg-Re) in Q345 steel.
Design/methodology/approach
The phase structure of Zn-Al-Mg-Re composite coatings has been determined by X-ray diffraction, whereas their surface morphology and cross-sectional microstructure as well as cross-sectional elemental composition have been analyzed by scanning electron microscopy and energy-dispersive spectrometry. Moreover, the corrosion resistance of Zn-Al-Mg-Re composite coatings has been evaluated by acetic acid accelerated salt spray test of copper strip.
Findings
Experimental results show that doping with La and Ce favors to tune the composition (along with the generation of new phase, such as LaAl3 or Al11Ce3) and refine the microstructure of Zn-Al-Mg galvanizing coatings, thereby significantly improving the corrosion resistance of the coatings. Particularly, Zn-Al-Mg-Re with 0.15% (mass fraction) La exhibits the best corrosion resistance among the tested galvanizing coatings.
Originality/Value
Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La) and cerium (Ce) (denoted as Zn-Al-Mg-Re) have been prepared on Q345 steel substrate by hot-dip galvanizing so as to improve the corrosion resistance of the transmission towers, and to understand the corrosion inhibition of the Zn-Al-Mg-Re coating.
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Zhikun Ding, Jian Zuo, Jiayuan Wang and George Zillante
A growing number of foreign consulting firms have been engaged in the Chinese construction market where the supervision system, as a kind of engineering consultant service has…
Abstract
Purpose
A growing number of foreign consulting firms have been engaged in the Chinese construction market where the supervision system, as a kind of engineering consultant service has been widely implemented. However, the performance of supervision system varies significantly across regions. Therefore, foreign consulting firms are in desperate need of related performance benchmarking statistics to determine the niche market. A major issue is lack of a quantitative method to objectively evaluate regional supervision systems’ performance. The paper aims to discuss these issues.
Design/methodology/approach
A new regional construction supervision system benchmarking model was developed via the principal component analysis method. This model is based on key performance indicators drawn from annual official statistics. This list of key indicators was refined by means of a focus group with selected experts. Consequently the performances of all 31 regional supervision systems were calculated and ranked.
Findings
Results indicate a general gap between coastal and inland regions. The various development trends of top 10 regions are analyzed and the underlying reasons are explored. Furthermore, the regions deserving more attention or currently lacking in development are identified. The supervision industry in China is shifting from a labor-intensive industry to a knowledge-intensive industry.
Originality/value
The proposed model provides a single quantitative parameter to conveniently benchmark the performance of various regions. The findings are vital for the benchmarking and clarification of future endeavor of the regional supervision systems and for foreign enterprises that are planning to enter the real-estate market in China.
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Gangling Hou, Yu Liu, Meng Li, Menghan Sun, Feng Sun, Xiuyun Zhu, Rong Pan and Dongyu Zhang
In recent years, a new type of double-layered containment structure of nuclear power plant has been built in China, named ACP1000 NNP. This paper aims to propose a new method to…
Abstract
Purpose
In recent years, a new type of double-layered containment structure of nuclear power plant has been built in China, named ACP1000 NNP. This paper aims to propose a new method to mitigate the seismic responses of this type of the structure.
Design/methodology/approach
The new base isolation structure (BIS)- tuned mass damper (TMD) structure was proposed and implemented only by modifying the connection between various components of NPPs, and the application of this concept design in ACP1000 was skillfully realized.
Findings
The new structure adopts the combination of structural form and function, adopts appropriate amplification of the seismic response of the secondary component, possesses advantages in explicit damping mechanism, good damping effect, robustness of seismic structures, simple implementation process, etc., and meets the special seismic safety requirements of the NPPs.
Originality/value
This seismic and hazard mitigation and BIS-TMD structure can avoid the risk of ACP1000 accidents caused by horizontal earthquakes.
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Lei Liu, Zongwei Xu, Dongyu Tian, Alexander Hartmaier, Xichun Luo, Junjie Zhang, Kai Nordlund and Fengzhou Fang
This paper aims to reveal the mechanism for improving ductile machinability of 3C-silicon carbide (SiC) and associated cutting mechanism in stress-assisted nanometric cutting.
Abstract
Purpose
This paper aims to reveal the mechanism for improving ductile machinability of 3C-silicon carbide (SiC) and associated cutting mechanism in stress-assisted nanometric cutting.
Design/methodology/approach
Molecular dynamics simulation of nano-cutting 3C-SiC is carried out in this paper. The following two scenarios are considered: normal nanometric cutting of 3C-SiC; and stress-assisted nanometric cutting of 3C-SiC for comparison. Chip formation, phase transformation, dislocation activities and shear strain during nanometric cutting are analyzed.
Findings
Negative rake angle can produce necessary hydrostatic stress to achieve ductile removal by the extrusion in ductile regime machining. In ductile-brittle transition, deformation mechanism of 3C-SiC is combination of plastic deformation dominated by dislocation activities and localization of shear deformation. When cutting depth is greater than 10 nm, material removal is mainly achieved by shear. Stress-assisted machining can lead to better quality of machined surface. However, there is a threshold for the applied stress to fully gain advantages offered by stress-assisted machining. Stress-assisted machining further enhances plastic deformation ability through the active dislocations’ movements.
Originality/value
This work describes a stress-assisted machining method for improving the surface quality, which could improve 3C-SiC ductile machining ability.
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The emergence of crowdfunding has provided a new way to solve the problem of financing difficulties for start-ups. Although crowdfunding has attracted great attention from the…
Abstract
Purpose
The emergence of crowdfunding has provided a new way to solve the problem of financing difficulties for start-ups. Although crowdfunding has attracted great attention from the government and industry, investors are still hesitating to invest online. This paper aims to investigate the investment behavior of China’s debt-based internet crowdfunding market and construct a model to explain online investment decisions from the perspectives of trust and economic valence.
Design/methodology/approach
This paper uses the survey method to verify the research model. The questionnaire was constructed based on the items in prior studies. The data were collected from users with project investment experience on a leading crowdfunding platform in China. A total of 474 valid responses were collected. Partial least squares-structural equation modeling was used in the data analysis.
Findings
This paper finds that initial trust and perceived benefits are the key factors influencing investment intentions; investors are more concerned about potential benefits than about risk; perceived benefits partially mediate the relationship between initial trust and investment intentions. Fundraisers’ reputation is also found to have a greater impact on investors’ initial trust than investors’ trust propensity.
Originality/value
The conclusions of this paper provide important insights into the design of internet crowdfunding platforms and the regulation of policymakers.
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Zhou Su, Xiangwang Kong, Tao He, Dongyu Wu, Jingjing Wu and Shaohe Zhang
Material extrusion technology is considered to be an effective way to realize the accurate and integrated manufacturing of high-performance metal diamond tools with complex…
Abstract
Purpose
Material extrusion technology is considered to be an effective way to realize the accurate and integrated manufacturing of high-performance metal diamond tools with complex structures. The present work aims to report the G4 binder that can be used to create metal composite filament loading high concentrations of large diamond particles through comparative experiments.
Design/methodology/approach
The quality of filaments was evaluated by surface topography observation and porosity measurement. And the printability of filaments was further studied by the tensile test, rheological test, shear analysis and printing test.
Findings
The results show that the G4 binder exhibits the best capacity for loading diamonds among G1–G4. The L4 filament created with G4 has no defects such as pores, cracks and patterns on the surface and section, and has the lowest porosity, which is about 1/3 of the L1. Therefore, the diamond-containing composite filament based on G4 binder exhibits the best quality. On the other hand, the results of the tensile test of L5–L8 filaments reveal that as the diamond content increases from 10% to 30%, the tensile strength of the filament decreases by 29.52%, and the retention force coefficient decreases by 15.74%. This can be attributed to the formation of inefficient bonding areas of the clustered diamond particles inside the composite filament, which also leads to a weakening of the shear strength. Despite this, the results of the printing test show that the diamond-containing composite filament based on the G4 binder has reliable printability.
Originality/value
Therefore, the G4 binder is considered to solve the most critical first challenge in the development of diamond-containing filament.
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Mei-yung Leung, Chen Dongyu and Anita M.M. Liu
The purpose of this paper is to explore the influence of personal values on students’ learning behaviours. Hong Kong construction students are often criticized, by both…
Abstract
Purpose
The purpose of this paper is to explore the influence of personal values on students’ learning behaviours. Hong Kong construction students are often criticized, by both practitioners and educators, as rote learners. To improve students’ learning processes, extensive research on a variety of aspects of construction education has been conducted. However, limited attention has been paid to the influence of personal values on students’ learning behaviours. The impact of personal value factors on the learning approaches of Chinese construction students in Hong Kong is investigated.
Design/methodology/approach
A questionnaire survey was conducted to ethically Chinese construction students in four universities in Hong Kong. A total of 820 questionnaires were distributed and 431 valid returns were collected.
Findings
The survey identified six influential values (namely, personal integrity, conservatism, determination, discipline, interpersonal relationships, and achievement), and shows that students who emphasize the virtues of personal integrity, determination, and a positive attitude toward achievement are better able to handle their interpersonal relationships, which will eventually lead them to engage in deep learning.
Originality/value
Work to develop appropriate value systems is thus recommended in freshmen courses, as is the use of cooperative learning approaches. Such value systems will have a long-term influence on the learning approaches of construction students.
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Ting Li, Jinsheng Zhang, Shicheng Wang, Dongyu Li, Zhifeng Lv and Jiangjun Jiang
This study aims to find a novel solution to the calibration of three-axis magnetometers to suppress errors of sensors. The nature of the calibration process is parameter…
Abstract
Purpose
This study aims to find a novel solution to the calibration of three-axis magnetometers to suppress errors of sensors. The nature of the calibration process is parameter estimation and hence the purpose of the paper is to calculate the error parameters and eliminate sensor errors and obtain the true value of the pure magnetic field.
Design/methodology/approach
The paper puts forward a calibration method using an alternative iteration looping optimization (AILO) to estimate the parameters. The proposed method divided the parameters to be estimated into two parts: a portion less than one and the other greater than one. Parameters with different orders of magnitude are calculated respectively, which let one part to be a known quantity and the other part is derived by the known quantity; the derived quantity is used to calculate the known quantity again, and looping iteration multiple times until the iteration termination condition is satisfied.
Findings
The simulation and experimental results indicate that the calibration accuracy is improved at least by two orders by the proposed method compared to the two-step method and the linear decreasing weight particle swarm optimization (LDW-PSO) algorithm which proves the validity of the proposed method.
Practical implications
The proposed method can improve the calibration accuracy of total magnetic field, which provides a reference to the calibration of three-axis magnetometers.
Originality/value
A calibration method based on the AILO is proposed in this paper, which is used to improve the calibration accuracy of the three-axis magnetometer.
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Xia Wang, Hong Ren, Weiguang Cai, Yan Liu and Lizi Luo
Green building (GB) has been actively promoted in many countries, but it has not become the mainstream in Chinese construction industry due to various reasons. This paper aims to…
Abstract
Green building (GB) has been actively promoted in many countries, but it has not become the mainstream in Chinese construction industry due to various reasons. This paper aims to investigate the major driving factors for the development of GB with reference of the Chinese construction market. Twenty-one factors influencing the development of GB were identified through a literature review, questionnaire survey, and face-to-face interview with professionals in the construction industry. Structural equation model was established to identify the critical driving path and three critical factors hierarchies. The result of model analysis also verifies the theoretical hypotheses that government body is the biggest motivation for the development of GB, and the path coefficient is high. The results demonstrate the necessity for the formulation of incentive policies and power of GB propaganda. We identify distinct government and market effects and then induce a government-led GB development path. These findings provide a valuable reference for government body aiming at promoting GB in the construction industry to put forward relevant policies and incentives and for the market body to understand the major driving factors and path when making decisions.