Wei Gong, Xiao-Yan Wang, Xiao Wang, Wen Wang and Yan-Li Yang
To ensure the reliable and safe operation of elevated-temperature pipes and equipment in the long term, it is essential to thoroughly assess the creep rupture life. Nevertheless…
Abstract
Purpose
To ensure the reliable and safe operation of elevated-temperature pipes and equipment in the long term, it is essential to thoroughly assess the creep rupture life. Nevertheless, there is currently no design code that specifies a creep rupture life evaluation method for non-nuclear elevated-temperature equipment. The paper aims to discuss this issue.
Design/methodology/approach
An analysis was conducted to compare the differences and conservativeness in calculating creep strain using three major codes (ASME-CC-2843, API-579 and BS-7910) based on the results of the 316H creep constitutive model and creep strain prediction. In addition, the creep resistances of 316H, 304H and 347H were compared. Subsequently, the ANSYS Usercreep subroutine was developed to compare the discrepancies between different codes under multiaxial stress conditions using numerical simulations.
Findings
BS-7910 employs the Norton creep model with calculation parameters for the average creep strain rate, which is not applicable for the engineering design stage. ASME-CC2843 code primarily focuses on the primary and secondary creep stages, making it more suitable for non-nuclear pipeline and equipment design. For 316H, the creep strain curves predicted by ASME-CC2843 and API-579 typically intersect at a specific point. By combining the creep strain predicted by ASME-CC2843 and API-579, 347H exhibits superior predicted creep resistance compared to 316H, whereas 316H exhibited better predicted creep resistance than 304H.
Originality/value
This study provides a guide for future evaluation methods and material choices for non-nuclear equipment and pipelines operating at elevated temperatures.
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Keywords
Hui-Feng Wang, Gui-ping Wang, Xiao-Yan Wang, Chi Ruan and Shi-qin Chen
This study aims to consider active vision in low-visibility environments to reveal the factors of optical properties which affect visibility and to explore a method of obtaining…
Abstract
Purpose
This study aims to consider active vision in low-visibility environments to reveal the factors of optical properties which affect visibility and to explore a method of obtaining different depths of fields by multimode imaging.Bad weather affects the driver’s visual range tremendously and thus has a serious impact on transport safety.
Design/methodology/approach
A new mechanism and a core algorithm for obtaining an excellent large field-depth image which can be used to aid safe driving is designed and implemented. In this mechanism, atmospheric extinction principle and field expansion system are researched as the basis, followed by image registration and fusion algorithm for the Infrared Extended Depth of Field (IR-EDOF) sensor.
Findings
The experimental results show that the idea we propose can work well to expand the field depth in a low-visibility road environment as a new aided safety-driving sensor.
Originality/value
The paper presents a new kind of active optical extension, as well as enhanced driving aids, which is an effective solution to the problem of weakening of visual ability. It is a practical engineering sensor scheme for safety driving in low-visibility road environments.
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Qu Shao‐cheng, Wang Xiao‐yan and Wang Yong‐ji
The purpose of this paper is to find a practical active sliding mode control approach for synchronization of two uncertain chaotic systems.
Abstract
Purpose
The purpose of this paper is to find a practical active sliding mode control approach for synchronization of two uncertain chaotic systems.
Design/methodology/approach
Sliding mode control approach is known to be an efficient alternative way to implement synchronization for uncertain chaotic systems. However, design of traditional sliding mode controller usually needs complex state transformation. Owing to a novel idea of virtual state feedback, a control strategy for synchronization of uncertain chaotic systems is presented, which does not need any complex state transformation. Furthermore, based on Lyapunov stability theory, a sufficient condition is drawn for the robust stability of the error dynamics of synchronization for uncertain chaotic systems.
Findings
A novel active sliding mode control approach is proposed to achieve the synchronization of two uncertain chaotic systems.
Research limitations/implications
The main limitation is that uncertainties must meet matched conditions.
Practical implications
The paper presents a useful control approach for synchronization of two uncertain chaotic systems.
Originality/value
The proposed sliding mode control approach based on novel virtual state feedback does not need any complex state transformation, unlike the traditional sliding mode control.
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Keywords
Yanqin Wang, Lulu Wang, Xiao Yan Liu, Hongru Yang, Yuan Zhang and Xiaosong Zhu
The effects of the thermo-mechanical treatment on the properties and microstructure of the Al–Cu–Mg–Ag alloy were investigated.
Abstract
Purpose
The effects of the thermo-mechanical treatment on the properties and microstructure of the Al–Cu–Mg–Ag alloy were investigated.
Design/methodology/approach
A short-duration preprecipitation process is designed prior to predeformation aging. The novel predeformation aging (solution treatment + holding at 185 °C for 15 min+ rolling deformation + aging at 185 °C, also named T8) was performed on a heat-resistant Al–Cu–Mg–Ag alloy.
Findings
The purpose of this study indicate that a short-duration heat treatment before predeformation is beneficial to the precipitation of O during the aging process. The precursors of O during this process might pin the dislocation and cause the grains to orient along some specific direction, which might be advantageous to the precipitation of O while disadvantageous to that of θ′. This novel thermal-mechanical process could result in an increase in the quantity and decrease in the size of the precipitation of O, which leads to a remarkable strength effect. The potential increases while the current density decreases with an increase in the deformation amount, which implies a smaller intergranular corrosion rate. The fine deformed structure leads to an opposite behavior in the exfoliation corrosion test compared with that for intergranular corrosion.
Originality/value
The intergranular corrosion resistance of the Al–Cu–Mg–Ag alloy is enhanced, whereas the exfoliation corrosion resistance is reduced by novel predeformation aging.
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Keywords
Clark Shi-Ming Tang, Thomas Li-Ping Tang and Xiao-Yan Li
This study aims to develop a Chinese core self-evaluations scale (CCSES) (Study 1) and examines the relationship between CCSES and self-reported job performance among…
Abstract
Purpose
This study aims to develop a Chinese core self-evaluations scale (CCSES) (Study 1) and examines the relationship between CCSES and self-reported job performance among entrepreneurs in private small and medium enterprises in People's Republic of China (Study 2).
Design/methodology/approach
In Study 1, the paper incorporated two indigenous Chinese constructs, team-based self-esteem and personal integrity, into the existing literature of CSE and developed a new CCSES using a sample of 300 Chinese entrepreneurs in Hangzhou, China. In Study 2, the paper validated the CCSES in a separate sample of 306 entrepreneurs and investigated the relationships between CCSES and self-reported job performance.
Findings
The paper identified four sub-constructs in the 13-item CCSES: personal self-esteem, team-based self-esteem, personal integrity, and self-competence. Results from exploratory and confirmatory factor analyses showed good psychometric properties and high reliability in Study 1. In Study 2, the paper found a good fit between the measurement model and the data, and a significant relationship between CCSES and the overall measure of job performance and its three components. Males had significantly higher Chinese core self-evaluations (CCSE) scores than females. There were no differences in CCSE scores across age and educational background.
Originality/value
Borrowing the CSE construct in the Western literature, the paper includes two indigenous Chinese constructs, team-based self-esteem and personal integrity, provides a new perspective of the CSE construct for entrepreneurs, and investigates its relationship with job performance in China.
Details
Keywords
Yuan Chen, Ziyue Yang, Bingsheng Liu, Dan Wang, Yan Xiao and Anmin Wang
This study aims to investigate the influence mechanism of expatriates' cultural intelligence (CQ) on expatriate effectiveness (task performance and premature return intention)…
Abstract
Purpose
This study aims to investigate the influence mechanism of expatriates' cultural intelligence (CQ) on expatriate effectiveness (task performance and premature return intention), identifying work engagement as a mediator and cultural distance as a boundary condition.
Design/methodology/approach
Drawing on the conservation of resource theory and the person–environment fit (P–E fit) theory, a moderated mediation model is built. Working with a sample of 303 international construction expatriates collected by snowball sampling, the hypotheses are tested by using the structural equation model analysis.
Findings
Work engagement partially mediates the relationship between expatriates' CQ and task performance, as well as fully mediates the relationship between expatriates' CQ and premature return intention. Cultural distance moderates the positive relationship between CQ and work engagement, as well as moderates the mediating effects of work engagement.
Research limitations/implications
The impacts of potential moderators (e.g. work–family conflict and organizational culture) on the relationship between CQ and expatriate effectiveness have not been considered in this study.
Practical implications
This study is useful for international construction firms to optimize the allocation of human resources.
Originality/value
This study contributes to the expatriate literature by adding empirical evidence to explain the influence mechanism of expatriates' CQ on expatriate effectiveness.
Details
Keywords
Ying Guo, Ting-Tsen Yeh, David C. Yang and Xiao-Yan Li
The purpose of this study is to understand the current trends and development of corporate social responsibility (CSR) reporting in emerging and developing economies and analyze…
Abstract
Purpose
The purpose of this study is to understand the current trends and development of corporate social responsibility (CSR) reporting in emerging and developing economies and analyze 106 Chinese central enterprises (CEs) that disclose CSR reports from 2004 to 2015.
Design/methodology/approach
This study analyzes all the CSR reports available to the public from CEs between 2004 and 2015 in China. This paper carefully examines the reporting patterns and standards in those CSR reports. CEs in China are focused on because state-owned companies account for a large proportion of the Chinese stock market because of their social and economic institutional characteristics.
Findings
The results in this paper confirm a growth trend in the numbers of CSR reports, as predicted. The results also suggest that the number of CSR reports from the CEs containing some assurance has dramatically increased. However, the findings indicate that the current content of the CSR reports may not fully meet the needs of users of information from different industries, regions and interests, as more than 20 CEs have formulated their own CSR framework. The lack of unified, sustainable reporting and assurance may reduce the comparability and effectiveness of CSR reporting.
Social implications
This study provides evidence of the trends and development of CSR reporting in China.
Originality/value
The findings extend the understanding of CSR reporting by analyzing Chinese CE data. The results also provide decision-useful information for the government and other policymakers when considering CSR reporting and assurance standards.
Details
Keywords
Ge Zhang, Liang Ma, Xin Zhang, Xiao Yan Ding and Yi Ping Yang
An increasing number of users join and become immersed in WeChat official accounts, but many users quit using these services as well. Nevertheless, most of the previous studies…
Abstract
Purpose
An increasing number of users join and become immersed in WeChat official accounts, but many users quit using these services as well. Nevertheless, most of the previous studies mainly focussed on the usage behavior. The purpose of this paper is to fill the gap by examining factors affecting users’ unfollow intentions for WeChat subscriptions in a Chinese context.
Design/methodology/approach
Structural equation modeling is used in our study. A field survey with 260 WeChat users is conducted to test the research model and hypotheses.
Findings
The results show the following interesting key findings: first, the effect of actual cost on users’ unfollow intentions is larger than the effect of opportunity cost; second, users’ unfollow intentions will decrease with the increase of users’ perceptions of information usefulness; third, the results of the control variables showed that only landing frequency has a negative effect on users’ unfollow intentions; and fourth, users’ demographic differences are also examined in regard to how they may affect users’ unfollow intentions.
Originality/value
First, this paper studies factors influencing users’ unfollow intentions for WeChat subscriptions from a social exchange theory perspective; the authors considered both extraneous factors and users’ internal perception factors potentially affecting users’ unfollow intentions, which has rarely been researched. Furthermore, the authors examined significant differences among users’ demographic characteristics in affecting users’ unfollow intentions. The results of the study provide a more comprehensive understanding of the influencing factors of users’ unfollow intentions.
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Xiao-Yan Ma, Yi-Wen Ren, Hui Li, Wei Li, Yanli Liang and Wenjiang Zheng
Silicon-containing groups were introduced into fluoroacrylate polymer to further improve the comprehensive performance of pressure-sensitive adhesive (PSA) for expanded…
Abstract
Purpose
Silicon-containing groups were introduced into fluoroacrylate polymer to further improve the comprehensive performance of pressure-sensitive adhesive (PSA) for expanded polytetrafluoroethylene (ePTFE) bonding.
Design/methodology/approach
A series of silicon-containing fluorinated acrylic copolymers were synthesized through free radical solution polymerization with vinyloxy trimethylsilane, allyltrimethylsilane, 3-(trimethoxysilyl)propyl methacrylate or 1,3,5-tris(3,3,3-trifluoropropyl) methylcyclotrisiloxane as silicon monomers, and comprehensive performance of the copolymers was evaluated based on Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), gel permeation chromatography, glass transition temperatures (Tg), differential scanning calorimetry, thermogravimetric analysis, water contact angle, the track, 180° peel strength, and shear holding power.
Findings
Based on the FTIR and XPS results, it is confirmed that the silicon monomers were successfully introduced into the fluorinated acrylate copolymer. XPS analysis indicated that the silicon groups had the tendency to enrich on the surface of the film, thereby reducing the F content on the film surface. The glass transition temperatures (Tg) of the PSAs increased when silicon monomers were introduced, while the thermal stability declined. The contact angles of the acrylic PSA films were increased with the introduction of silicon monomers. From the perspective of bonding performance, the track, 180° peel strength and shear holding power decreased to varying degrees compared to silicon-free PSA, except significantly elevated holding power with MPS as the silicon monomer.
Originality/value
Silicon-containing fluorinated acrylic copolymers were synthesized, and the comprehensive performance was evaluated as PSAs of ePTFE for the first time.
Details
Keywords
Liang Ma, Xin Zhang and Xiao Yan Ding
The rise of social media has gained increasing attention in recent years; however, few studies have focused on social media users’ specific behavior and subjective well-being. To…
Abstract
Purpose
The rise of social media has gained increasing attention in recent years; however, few studies have focused on social media users’ specific behavior and subjective well-being. To fill this research gap, the purpose of this paper is to develop an integrated model to investigate factors that affect social media user’s share intention and the relationship between user’s share intention and subjective well-being.
Design/methodology/approach
Structural equation model is used in this study. A field survey with 398 WeChat users is conducted to test the research model and hypotheses.
Findings
The empirical results show that: utilitarian value, hedonic value, user satisfaction and information source credibility are important factors affecting users’ share intention; users’ share intention positively affects user’s subjective well-being; moderating effects show that relative significance positively moderates the relationship between utilitarian value and users’ share intention; and users’ demographic characteristics differences actually exist in users’ share intention.
Originality/value
First, the authors clear that factors affect social media users’ share intention from the perspective of customer-perceived value. The results deepen our understanding about the factors that affect WeChat users’ share intention. Second, the authors focus on the effect of users’ specific behavior on users’ subjective well-being and found that users’ share intention is one of the important aspects that affect user’s subjective well-being. More importantly, the authors tested users’ characteristic differences in social media users’ share intention, which have previously received limited attention.