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This paper aims to investigate the improvement of Sn58Bi solder properties by Ni nanoparticle to provide theoretical support in the field of electronic packaging.

In this study, nickel nanoparticles (Ni NPs) were doped into Sn58Bi solder as a reinforcing agent to prepare a composite solder. The wettability of composite solder, melting characteristics of solder alloy, microstructure of joints, mechanical properties and intermetallics growth at the interface were investigated.

Test results show that Ni had little substantial effect on the solders alloy melting temperature yet decreased the alloy undercooling. Notably, Ni enhanced solders wettability on Cu substrates. The spreading area increased by 14% at 0.6 wt.% Ni. The Ni refined the microstructure of Sn58Bi solder joints and inhibited the coarsening of the Bi-rich phase in the solder. At the same time, it also led to the production of free intermetallic compounds, increasing growth of the intermetallic compound (IMC) layer. However, upon surpassing 0.6 wt.% Ni, (Cu, Ni)₆Sn₅ accumulated and formed irregular clumps in the matrix. The grain size of the IMC layer gradually decreased as Ni was added. In shear tests, the fracture of joints occurred mainly inside the solder matrix. Sn58Bi-0.6Ni joints displayed a 40% rise in shear strength and a 25% rise in Vickers hardness. In addition, the appearance of dimples at the fracture indicated the improved flexibility of joints.

In this paper, Ni nanoparticle with different contents were added to Sn58Bi solder to prepare a composite solder, and the properties of the composite solder were investigated from different perspectives.

Ultracapacitors find extensive applications in various fields because of their high energy density and long cycling periods. However, due to the movement of ions and the arrangement patterns on rough/irregular electrode surfaces during the charge and discharge process of ultracapacitors, the parameters of ultracapacitors usually change with the variation of operating conditions. The purpose of this study is to accurately and quickly identify the parameters of ultracapacitors.

A variable forgetting factor recursive least square (VFFRLS) algorithm is proposed in this paper for online identifying the equivalent series resistance and capacitance C of ultracapacitors. In this work, a real-time error-based strategy is developed to adaptively regulate the value of the forgetting factor of traditional forgetting factor recursive least square (FFRLS) algorithm. The strategy uses the square of the average time autocorrelation estimation of the prior error and the posterior error between the predicted output and the actual output as the adjustment basis of forgetting factors.

Experiments were conducted using the proposed scheme, and the results were compared with the estimation results obtained by the recursive least squares (RLS) algorithm and the traditional FFRLS algorithm. The maximum root mean square error between the estimated values and actual values for VFFRLS is 3.63%, whereas for FFRLS it is 9.61%, and for RLS it is 19.33%.

By using the proposed VFFRLS algorithm, a relatively high precision can be achieved for the online parameter estimation of ultracapacitors. Besides, the dynamic balance between parameter stability and tracking performance can be validated by dynamically adjusting the forgetting factor.

This study aims to report the development and experimental evaluation of two kinds of PANI@semiconductor based photocathodic anti-corrosion coating, for application on stainless steel substrates.

PANI was in situ chemical polymerized on TiO₂ and BiVO₄ particles, and FT-IR and SEM/EDS were used to understand the characteristics and elemental distribution of the composite particles. Composite coatings, which consisted of epoxy, PANI@TiO₂ or PANI@BiVO₄ and graphene, were prepared on the 304L stainless steel. Photoelectrochemical response measurement, electrochemical tests and immersion tests were used to assess the anti-corrosion performance of the prepared coatings in 45°C 3.5 wt.% NaCl solution. And the corrosion protection mechanism was further explained by combining with surface observation.

The photoelectrochemical response tests revealed the good photocathodic effect of the coatings, and the reversible oxidation-reduction properties of PANI (pseudocapacitive effect) leading to the repeated usage of the coatings. Consequently, the anti-corrosion mechanism of the composite coating is attributed to the physical barrier effect of the coating, the anodic protection effect of PANI and the photocathodic and energy store effect.

These kind coatings could prevent corrosion from day to night for stainless steel, which has great engineering application prospects on stainless steel corrosion protection.

Geographical Indication (GI) products represent a distinct association between a product and its specific geographic origin. While scholars have acknowledged the impact of GI products on destination marketing, there exists a dearth of research concerning the underlying mechanism through which the perceived value of GI products influences consumers' intention to visit the region of origin.

This study utilizes the cognitive appraisal theory as a basis for constructing a conceptual framework to investigate the association between the perceived value of GI products, emotional reactions and destination brand awareness.

By placing particular emphasis on the diverse impacts of perceived value on tourists' affective responses and travel intentions, the results of this research offer significant contributions to the field of destination marketing.

A deeper understanding of the perceived value of GI products can enable destination marketers to effectively attract prospective tourists and foster a stronger connection between tourists and the regions of origin.

This research aims to address the knowledge gap regarding the influence of electronic performance monitoring (EPM) on supervisors' behavior. Building upon the sociomaterial perspective and the general model of disinhibition, the study explores the internal mechanisms and boundary conditions between supervisor EPM use and supervisor undermining.

An online survey was administered via the Sojump platform, inviting supervisors from diverse industries in China to participate in a three-wave study, each wave being approximately two weeks apart. The study gathered multi-wave data from 225 supervisors to assess the conceptual model.

The results showed that supervisor EPM use was positively related to sense of power, which in turn positively related to supervisor undermining. Furthermore, supervisors' individual identity orientation moderates the relationship between supervisor EPM use and sense of power, as well as the indirect relationship between supervisor EPM use and supervisor undermining through sense of power.

This study advocates for responsible EPM use to mitigate supervisor undermining (e.g. making subordinates feel incompetent) and minimize negative leadership behaviors.

The presented results signify a substantial progression in comprehending the interplay between supervisor EPM use and individual identity orientation, and their combined impact on the sense of power and subsequent supervisor undermining.

Based on upper echelon theory and signaling theory, we aim to examine the impact of returnee executives on firms’ relative exploratory innovation focus and the moderating effect of economic policy uncertainty on this relationship.

Using panel data of Chinese listed companies from 2009 to 2020, we obtained empirical evidence to support our arguments.

Returnee executives positively influence firms’ relative exploratory innovation focus. This means that firms with returnee executives will shift the focus of their innovation activities toward exploratory innovation more than exploitative innovation. In addition, we find that economic policy uncertainty strengthens this relationship.

First, by showing how returnee executives positively influence firms’ shift in focus to exploratory rather than exploitative innovation, we expand our understanding of firms’ trade-offs between exploratory and exploitative innovation. Second, this study examines how returnee executives influence the relative importance that firms place on exploratory and exploitative innovation, allowing us to build a realistic and nuanced view of how returnee executives influence firms’ strategic choices. Finally, this study expands the strategic leadership literature and responds directly to the call for studies focusing on how institutional environmental conditions and executive characteristics work together to shape firm outcomes.

Based on boundary theory, the authors try to clarify the boundaries of multiple environmental regulations. This paper aims to explore the strategic choices of multiple environmental regulations, analyze their spatial impact on green technology innovation and clarify the implementation priorities of multiple environmental regulations in various regions.

The authors construct an asymmetric response model based on the boundary theory perspective to analyze the strategic choices of different environmental regulations. In addition, dynamic spatial econometric methods are used to empirically analyze the differentiated regulatory boundaries of command-control type, market-incentive and voluntary-participation in environmental regulations and their spatial effects on green technology innovation.

Strict compulsory boundaries are formed in China when the command-control and market-incentive types are selected in a dynamic spatial and competitive game environment. When voluntary participation is selected, strict compulsory or loose basic boundaries are formed in each region. The command-control type is highly dependent on geographical distance, the market-incentive type is more dependent on an economic connection and the voluntary-participation type has obvious spatial spillover effects under the spatial weight matrix of geographical distance and economic connection. When Eastern China chooses voluntary participation in environmental regulation, the incentive effect on green technology innovation is the strongest. Middle China is the market-incentive type, and Western China is the command-control type. Command-control type and market-incentive type form strong complementary effects in dynamic spatial environments.

From the boundary theory perspective, this study analyzes the differentiated dynamic spatial boundaries of command-control, market-incentive and voluntary-participation in environmental regulations. Analyze the spatial impact of multiple environmental regulations on green technology innovation and clarify the implementation priorities of multiple environmental regulations in various regions.

With the widespread collection and utilization of user data, privacy security has become a crucial factor influencing online engagement. In response to the growing concern about privacy security issues on social media, this research aims to examine the key causes of social media users' privacy calculus and how the balance between perceived privacy risks and benefits affects users' privacy concerns and their subsequent willingness to disclose personal information.

The characteristics of the privacy calculus were extracted through partially structured interviews. A research model derived from privacy calculus theory was constructed, and latent variable modeling was employed to validate the proposed hypotheses.

Information sensitivity, experiences of privacy violations, social influence and the effectiveness of privacy policies influence users' privacy calculus. Privacy risk positively influences privacy concerns. Personal information disclosure willingness is positively influenced by privacy benefits and negatively influenced by privacy concerns, with both paths moderated by social media identification.

This study explores the key antecedents of users' privacy calculus and how these factors influence privacy concerns and subsequent willingness to disclose information on social media. It offers new insights into the privacy paradox observed within social media by validating the moderating role of social media identification on users' information disclosure willingness.

Although the literature provides insights into the role of experiential learning based on prototypes in identification of latent customer need, it offers different views on the role of product prototypes in improving the efficacy of learning customer need, and also neglects the role of vicarious learning in prototype-based experiential learning. In a data-rich environment, market big data create new opportunities to learn from vicarious, digitalized experiences that are not observable with prototype-based learning. Therefore, the purpose of this study is to compare the effects of product prototype strategies – basic prototype strategy and enhanced prototype strategy – on identification of latent customer needs, and determine how each prototype strategy interacts with vicarious learning based on market big data to identify latent customer needs.

We collected data from 299 Chinese manufacturing firms via on-site surveys to explore our research question. All of our hypotheses were supported by the regression results.

This study finds that both the enhanced and basic prototype strategies (experiential learning from direct market experience based on prototyping) have positive effects on latent need identification, but the effect of enhanced prototypes is stronger. Furthermore, the enhanced and basic prototype strategies have different interaction effects with market big data (vicarious learning from indirect market experiences) on latent need identification.

This research extends the literature on prototype-based learning for latent need identification. It also contributes to the experiential prototype-based learning literature by exploring the role of vicarious learning based on market big data.

Based on the computers as social actors (CASA) theory, this study aims to explore the impact of three characteristics of virtual influencers (conversational tone, autonomy and responsiveness) on social presence, telepresence and customer engagement.

Using the purposive sampling technique, online survey was administered to Chinese Gen-Z consumers engaging with virtual influencers. Subsequently, 357 respondents were sampled. SPSS 29.0 and Smart PLS 4.0 were used to perform the analyses.

The results show that conversational tone and responsiveness have significant positive effects on both social presence and telepresence. Autonomy has a positive effect on telepresence, but not social presence. Social presence and telepresence have a positive impact on customer engagement.

As a burgeoning field, there is still uncertainty among both practitioners and researchers about the methods that virtual influencers engage their users in the context of social media. Limited research has focused on presence (social presence and telepresence) due to virtual influencers. Therefore, the CASA theory offers valuable insights into how virtual influencers’ characteristics contribute to the presence and customer engagement and provides practical guidance for the design of virtual influencers.