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Detection of hidden defects of aluminum alloy plate with damping coating is a challenging problem. At present, only a few non-destructive testing methods exist to address this engineering problem. Without the restriction of skin effect, remote field eddy current (RFEC) overcomes the interference caused by the damping coating. The RFEC, which has potential advantages for detecting the hidden defects of aluminum plate with damping coating, can penetrate the metal plate to detect buried depth defects. This study aims to test how thick the RFEC sensor can penetrate the metal plate to detect the buried defects.

The magnetic field distribution characteristics are analyzed, the magnetic field intensity distribution is calculated, and the structure and parameters of the coil, magnetic circuit and shielding damping are determined through the two- and three-dimensional finite element simulation methods. Optimal excitation frequency is obtained, and the distance between the excitation coil and detection coil is determined by analyzing the relationship between excitation frequency and remote field points.

Simulation and experimental results verify the feasibility of applying the RFEC detection technology in detecting the hidden defects of aluminum alloy plate with damping coating.

In this paper, the RFEC testing model of hidden defects in aluminum plate sample with damping coating is established by using the finite element method.

The purpose of this paper is to present a new disruptive maintenance model based on new technologies.

The approach is carrying out through the impact of the Industry 4.0, Internet of things, big data, virtual reality and additive manufacturing on maintenance.

The findings are that new technologies are an evolutionary challenge that is immediately affecting maintenance engineering. It presents a unique opportunity to make a disruptive evolution of maintenance.

The correct development of Maintenance 4.0 relates to the correct implementation of Industry 4.0.

Maintenance 4.0 will greatly improve the main operating indicators: safety, reliability, availability and cost.

Maintenance 4.0 will contribute to a circular and sustainable economy.

For the first time, a complete new Maintenance Engineering 4.0 model is proposed. The application of the new technologies appears in each specific maintenance process of the product life cycle.

This study aims to investigate whether firms purchase directors' and officers' liability (D&O) insurance when the country-level economic policy uncertainty (EPU) is high.

This study uses D&O insurance data from Chinese listed firms between 2003 and 2019 to conduct regression analyses to examine the association between D&O insurance and EPU.

The results show that government EPU, despite being an exogenous factor, increases the likelihood of firms' purchasing D&O insurance, and this effect is more pronounced when firms are exposed to great share price crash risk and high litigation risk, suggesting that firms intend to purchase D&O insurance possibly due to the accentuated stock price crash risk and litigation risk associated with EPU. In addition, the results indicate that the effect of EPU on the D&O insurance purchase decision is moderated by the provincial capital market development and internal control quality.

The study highlights the role of uncertain economic policies in shareholder approval of D&O insurance purchases.

The study enriches the literature on the determinants of D&O insurance purchases by documenting novel evidence that country-level EPU is a key institutional factor shaping firms' decisions to purchase D&O insurance.

This paper aims to review the effects of home regulatory institutions on outward foreign direct investment (OFDI) in the context of China and discuss the extent to which they can be extended to other emerging markets. The authors especially compare these empirical studies with theoretical discussions in each category, identify research gaps and suggest future research ideas. Practical implications are discussed.

It focuses specifically on three categories of regulatory institutions, including overall institutional development, liberalization of OFDI policies and state ownership (and its closely approximate forms). Using a systematic review, this paper has reviewed 26 empirical studies (23 quantitative and 3 qualitative studies) published in peer-reviewed journals.

These studies suggest that overall institutional development toward a market economy in general leads to increased OFDI, but this effect is contingent on the stage of such development and the capabilities of Chinese multinationals. Liberalized and supportive OFDI policies also facilitate OFDI activities but only into selective areas. Findings on state ownership have been mixed.

This review offers a full picture of empirical evidence on how multiple levels of regulatory institutions affect OFDI from China. In this way, the authors can identify the research gaps between theoretical discussions on home institutions and OFDI and empirical evidence. Thus, they make suggestions for future directions of studies.

The purpose of this paper is to use the wavelet neural network and genetic algorithm to study the effects of polyalphaolefin, TMP108 and OCP0016 on the kinematic viscosity, viscosity index and pour point of lubricating oil.

Wavelet neural network is used to train the known samples, test the unknown samples and compare the obtained results with those obtained with a traditional empirical formula.

It is found that the wavelet neural network prediction value is closer to the experimental value than the traditional empirical formula calculation value.

The results show that the wavelet neural network can be used to study the physical and chemical indexes of lubricating oil.

Self-organization has been regarded as a tool for the synthesis of well-defined organic nanostructures. Heterocyclic annulated perylene diimides are the subjects of considerable current research studies. The purpose of this study is to reveal the photophysical property, electronic structure and solid-state packing of O-heterocyclic annulated perylene diimide.

Asymmetrically five-membered O-heterocyclic annulated perylene diimide (OAPDI) was synthesized. Structure and purity of OAPDI were confirmed by ¹H NMR, ¹³C NMR, IR and mass spectral techniques. Photophysical properties of OAPDI were studied using UV–vis absorption and fluorescence in both solution (CHCl₃) and solid state. Scanning electron microscopic and atomic force microscopy were used to characterize the surface morphology of OAPDI. Conducting properties of the OAPDI were evaluated by current–voltage measurements. The compounds geometries were also optimized at 6-31G* using density functional theory.

The UV–vis absorption and fluorescence spectra of OAPDI in solution are blue-shifted in comparison with that of unsubstituted perylene bisimide. Solid-state UV–vis measurements of OAPDI indicate that it is capable of forming highly ordered structure. The non-covalent interactions, electrostatic attraction and p-p stacking moieties of OAPDI synergistically guide assembly and domain growth while maintaining the interpenetrating network of nanofibers in the solid film. The OAPDI gave higher current at −2.0 V (0.68 µA) and 4.0 V (1.0 µA).

This study will be helpful for exploring feasible routes to acquire soluble perylene diimides and well-defined organic nanostructures. Furthermore, such molecular tailoring approach would be helpful for designing and synthesizing novel organic semiconductive materials with excellent charge-transporting and light-emitting capabilities.

The COVID-19 pandemic has dramatically disrupted everyday life, leading to a cascade of negative emotional responses such as death anxiety. Against this backdrop, the purpose of this paper is to focus on the buffering effect of brand attachment on death anxiety by exploring the roles of brand concepts and brand positioning on psychological compensation for security.

This multi-method paper features four studies and shows how brands can offer emotional support under high-risk circumstances.

Study 1 includes two surveys which offer preliminary evidence that death anxiety can enhance consumers’ brand attachment. Study 2 reveals a causal effect wherein consumers experiencing death anxiety are more likely to attach to brands with a self-transcendence (vs self-enhancement) concept. Study 3 examines the mediating role of need for security in the relationship between death anxiety and attachment to brands with a self-transcendence concept. Further, Study 4 indicates the moderating role of brand positioning: self-transcendence brands adopting local (vs global) positioning strategies are more likely to satisfy consumers’ need for security, thereby leading to strong brand attachment.

The findings of this paper contribute to the brand attachment literature and to the global branding literature regarding consumers’ emotional responses in the context of COVID-19. This paper innovatively frames brand concepts and brand positioning and provides actionable guidelines to help brands satisfy consumers’ needs amid a worldwide crisis.

The screw extruder is applied in cement-three-dimensional (3D) printing. The cement paste flow in 3D printing is the typical Herschel–Bulkley fluid. To understand the flow in the channel, the improved lattice Boltzmann method (LBM) is proposed.

For Herschel–Bulkley flow, an improved LBM is presented to avoid the poor stability and accuracy. The non-Newtonian effect is regard as a special forcing term. The Poiseuille flow is taken to discuss the detailed process of the method. With the method, the analytical solution and numerical solution are obtained and compared. Then, the effect of the initial yield stress on the numerical solution is both explored by the shear-thickening fluid and the shear-thinning fluid. Moreover, the variations of the relative errors under different lattice nodes and different power-law indexes are analyzed. Finally, the method is applied into the simulation of the flow in the extruder of cement-3D printing.

The results show that the improved method is effective for Herschel–Bulkley fluids, which can simulate the flow in the extruder stably and accurately.

The simulation can contribute to understand the cement paste flow in the screw extruder, which helps to optimize the structure of the extruder in the following periods.

The improve method provide a new way to analyze the flow in the extruder of cement-3D printing. Also, in the past research, LBM for Herschel–Bulkley fluid is ignored, whereas the study can provide the reference for the numerical simulation.

Given the great upheaval in the international situation and the increasing operating risk in international business, research on corporate diplomacy is thriving. However, it still lacks clear conceptualization and operationalization. Based on social capital theory, our study conceptualizes corporate diplomacy as a three-dimensional construct and quantifies its distinct and combined impacts on multinational enterprises’ (MNE) subsidiary performance.

This research analyzes 134 responses collected from a questionnaire survey among key informants in Chinese MNEs using the regression method.

This research finds that corporate diplomacy is positively correlated with MNEs’ subsidiary performance. Specifically, compatriot-oriented diplomacy is the most effective, followed sequentially by host-partner-oriented and host-regulator-oriented diplomacy. In addition, compatriot-oriented diplomacy substitutes for host-partner-oriented diplomacy but complements host-regulator-oriented diplomacy in enhancing subsidiary performance.

Our research enriches the conceptualization and operationalization of corporate diplomacy and provides a nuanced view of its distinct and combined effects on MNEs’ subsidiary performance.

This study aims to theorize a knowledge-based perspective on organizational commitment and turnover intentions among knowledge workers. The authors contribute by examining the impact of knowledge sharing, and managerial human capital respectively, on commitment and turnover in a sample of 274 knowledge workers (engineers) from India. Additionally, the authors examine the crucial moderating role of intra-firm causal ambiguity on these relationships.

Using structural equation modeling and analysis of survey responses, the authors test a moderated mediation model to provide evidence of the positive impact of knowledge sharing and human capital, respectively, on turnover intention, mediated by organizational commitment. More importantly, the authors theorize and present evidence on the moderating role of intra-firm causal ambiguity, on these relationships.

The authors find that knowledge sharing behaviors are both intrinsically and extrinsically motivating for knowledge workers, which results in their emotional attachments and higher levels of identification and commitment, which subsequently results in lower turnover intention. Our findings also highlight the role of intra-firm causal ambiguity in making things difficult for organizations to retain talented employees in tough environments.

The authors provide a knowledge-based perspective of commitment and turnover in knowledge-intensive work contexts. The authors also contribute by provide an interesting account of the role of intra-firm causal ambiguity in knowledge processes leading to commitment.