Purpose: The purpose of this paper is twofold: first, to explain whether consumer engagement in social media brand communities (SMBCs) motivates consumer brand loyalty; and second, to explore the antecedents of consumer engagement by developing a model based on personal engagement theory. Design/methodology/approach: Online survey data from 279 brand community members of Weibo (one of the most popular social media websites in China) were used to test the proposed model. Structural equation modeling with partial least squares was performed to test both the measurement model and the structural model. A hierarchical multiple regression analysis was conducted to examine the interaction effects. Findings: The findings show that three factors, namely, recognition, community identification and self-efficacy, had significant positive effects on consumer engagement in SMBCs, which consequently enhanced brand loyalty. Self-efficacy moderated the effects of both community identification and recognition on consumer engagement. The impacts of three factors on consumer engagement are contingent upon the type of SMBCs. Originality/value: This study extends and advances the literature on consumer engagement by explaining consumer engagement in SMBCs from a new theoretical lens. This study also enriches personal engagement theory by investigating the effects of the interaction between different conditions of engagement. In addition, this study contributes to brand loyalty literature by providing empirical evidence of the impact of consumer engagement on brand loyalty. Finally, this study contributes to the online brand community study by introducing personal engagement theory into SMBC context, and examining the moderating role of SMBC types.

Background: Online health communities (OHCs) provide a new channel for users to obtain more health-related information and support, playing an important role in alleviating hospital congestion and uneven medical resource distribution, especially during the COVID-19 pandemic in China. An in-depth study of users’ continuous usage is of great value for the long-term development of OHCs. Objective: The purpose of this study is to explore the factors that influence users’ continuous usage in online health communities based on the theory of planned behavior (TPB) and social cognitive theory (SCT). Methods: Data from 480 users with experience in online health communities were collected through a questionnaire survey, and structural equations were applied to verify the model hypotheses empirically. Results: Self-efficacy and controllability have significant effects on users’ continuous intention; attitude has a significant relationship with continuous intention; social norms have a positive effect on continuous intention. Moreover, the relationship between continuous intention and behavior is positive. Self-efficacy and outcome expectations have significant positive associations with continuous usage. Finally, system quality, information quality, and social interaction ties have significant and positive relationships to continuous usage. Conclusion: To improve the level of user’s continuous usage, online health service providers can improve the quality of the community by organizing the website’s page layout, navigation menus, and site elements to ensure users quickly search and find what they want meanwhile try to change people’s cognition gradually, in addition, decision and policymakers should provide more favorable policies to stimulate and help provider in building and managing strategic plans for sustaining a thriving online community. A supportive climate in society through public service advertisements and others for the sake of OHCs is necessary. Limitations: (1) This study collected data through a cross-sectional survey. Thus, it lacked the process of capturing the changes in participants’ attitudes toward all variables. (2) The environmental factors in SCT theory need to be more comprehensive, containing online factors without offline factors. (3) The dates were obtained from China, which neglects the different cultural content.

In order to study the effect of nitriding or shot peening on the surface modification and fatigue properties of martensitic stainless-steel Custom 465, the residual stress and micro-hardness of the strengthened layer are determined by X-ray and micro-hardness tester, respectively. The up-and-down method is used to measure the rotational bending fatigue strength at 1 × 10⁷ cycles, and the fatigue fracture characteristic is observed by scanning electron microscopy. The relationship between surface residual stress and internal fatigue limit of surface strengthening treatment is discussed. Results show that nitriding or shot peening surface strengthening layer forms a certain depth of compressive residual stress, where in the surface compressive residual stress of the nitrided specimens is greater than the shot peened specimens. The micro-hardness of the nitrided or shot peened surface strengthening layer is significantly improved, where in the surface micro-hardness of nitriding specimens are higher than shot peening specimens. The nitriding or shot peening surface strengthening can significantly improve the fatigue limit of Custom 465, wherein the fatigue limits of nitrided and shot peened surface strengthened specimens are 50.09% and 50.66% higher than that of the un-surface strengthened specimens, respectively. That is, the effect of the two strengthening methods on fatigue limit is not very different. The fracture characteristics show that the fatigue crack of the un-surface strengthened specimens originates from the surface, while the fatigue crack of surface strengthened specimens originates from the subsurface layer under the strengthened layer. The relationship between the internal fatigue limit and the surface residual stress of the surface strengthened specimen can be used as a method for predicting the fatigue limit of the surface strengthened specimens.