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Prior studies fail to reach a consensus on the effects of extrinsic motivation (EM) on knowledge contribution in virtual communities. To fill this research gap, this research proposes two mechanisms of EM – direct effect versus indirect effect via intrinsic motivation (IM) – and introduces prosocial motivation (PSM) as the moderator to define the valence of these two mechanisms.

This research adopts structural equation modeling to validate hypotheses based on 448 responses from XiaoMi online community users.

The results of the moderated mediation analysis show that the direct effect, indirect effect via IM and total effect of EM on knowledge contribution are contingent on the level of PSM. Specifically, as the level of PSM increases, the direct, indirect and total effects of EM on knowledge contribution and the effects of EM on IM change from positive to insignificant and then to negative. Although IM constantly plays an important role across levels of PSM, its effect is stronger when the degree of PSM is high.

This paper advances knowledge of an integrated framework of EM by simultaneously describing its direct and indirect effects, describing its positive and negative effects and untangling the boundary conditions under which each effect of EM applies.

This paper aims to propose a bed and breakfast (B&B) recommendation method that takes into account review timeliness and user preferences to help consumers choose the most satisfactory B&B.

This paper proposes a B&B ranking method based on improved intuitionistic fuzzy sets. First, text mining and cluster analysis are combined to identify the concerns of consumers and construct an attribute set. Second, an attribute-level-based text sentiment analysis is established. The authors propose an improved intuitionistic fuzzy set, which is more in line with the actual situation of sentiment analysis of online reviews. Next, subjective-objective combinatorial assignments are applied, considering the consumers’ preferences. Finally, the vlsekriterijumska optimizacija i kompromisno resenje (VIKOR) algorithm, based on the improved score function, is advised to evaluate B&Bs.

A case study is presented to illustrate the use of the proposed method. Comparative analysis with other multi-attribute decision-making (MADM) methods proves the effectiveness and superiority of the VIKOR algorithm based on the improved intuitionistic fuzzy sets proposed in this paper.

Proposing a B&B recommendation method that takes into account review timeliness and user customization is the innovation of this paper. In this approach, the authors propose improved intuitionistic fuzzy sets. Compared with the traditional intuitionistic fuzzy set, the improved intuitionistic fuzzy set increases the abstention membership, which is more in line with the actual situation of attribute-level sentiment analysis of online reviews.

The purpose of this paper is to clarify the effect of compressive stress on cavitation-erosion corrosion behavior of 304 stainless steel.

Compressive stresses of 60 MPa and 120 MPa were applied to 304 stainless steel through a self-designed loading device, and cavitation erosion-corrosion tests were performed using an ultrasonically vibratory apparatus. Scanning electron microscope and X-ray diffraction were used to analyze the microstructure evolution, and corrosion behavior was studied by electrochemical analysis.

The cavitation weight loss of 304 stainless steel decreased with the compressive stress. After cavitation corroded for 8 h, the weight loss for the specimen with 120 MPa compressive stress was 5.11 mg/cm², which was reduced by 56.7% from that of the specimen without loading stress (11.79 mg/cm²). The reason can be attributed to that compressive stress promoted the deformation-induced martensitic transformation during the cavitation process, which could not only provide a cushioning effect by absorbing cavitation impact energy but also improve the hardness of 304 stainless steel.

Compressive stress was found to restrain the cavitation damage on 304 stainless steel, and the corresponding mechanism was proposed.

The primary objective of this research is to explore the underlying mechanisms of social ties influencing lurking behaviour in Microblog by combing role theory and social identity theory.

An online survey of 312 Microblog users in China was conducted to test the proposed research model and hypotheses. The partial least squares (PLS) approach was used to analyse the data.

The results show that social ties affect lurking behaviour on Microblog in two ways, directly and indirectly through role stress. Social ties have a negative direct impact on lurking behaviour. Based on the multiple mediation analysis, social ties positively affect lurking through role overload and negatively affect lurking via role ambiguity. Perceived heterogeneity strengthens the positive effects of social ties on role overload and conflict, and weakens the negative impact of social ties on role ambiguity. Social identification weakens the positive relationship between social ties and role overload and strengthens the negative relationship between social ties and role ambiguity.

This study extends the literature on the social interaction reasons behind lurking behaviour in Microblog by revealing the effects of social ties in Microblog. The theoretical mechanisms of social ties on lurking behaviour in Microblog are unveiled by discovering the direct effect of social ties, the mediating effects of multidimensional role stress, and the moderating effects of different kinds of social identity.

The purpose of this paper is to improve the corrosion resistance of stainless-steel bipolar plate by magnetron sputtering.

TiC/amorphous carbon composite film was deposited by magnetron sputter at four different temperature of 25°C, 200°C, 300°C and 400°C. The morphology, composition and structure of the film were characterized by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. And its corrosion behavior was analyzed through electrochemical impedance spectroscopy, potentiodynamic and potentiostatic polarization tests.

A compact TiC/amorphous carbon film was prepared by magnetron sputtering on 316L stainless steel, and the particles of the film were refined with the increase in sputtering temperature. High temperature promoted the formation of TiC and C–C sp² hybrid carbon, but excessively high temperature caused the oxidation of Ti and a significant decrease in sp² hybrid carbon. The corrosion resistance of the film increased with the temperature, and the corrosion current density polarization at 0.86 V and 1.8 V for TiC/a–C film prepared at 400 °C is only 1.2% and 43.2% of stainless steel, respectively.

The corrosion resistance of amorphous carbon films was improved by the doping of Ti carbide, and the appropriate sputtering temperature was obtained.

Nickel-aluminum bronze (NAB) has been widely used in ship propellers. It is always subjected to local micro-plastic deformation in service environments. This paper aims to study the influence of plastic deformation on the mechanical strength and corrosion resistance of NAB in 3.5 Wt.% NaCl solution.

Scanning electron microscope and X-ray diffraction were used to analyze the microstructure of NAB alloy with different plastic deformations. Mechanical properties of the sample were measured by tensile experiment, and corrosion behavior was studied by electrochemical measurements and the long-term immersion corrosion test.

Results showed that the plastic deformation caused lattice distortion but did not change the microstructure of NAB alloy. Microhardness and yield strength of NAB were significantly improved with the increase of deformation. The lattice distortion accelerated the formation of corrosion product film, which made the deformed alloy show a more positive open-circuit potential and an increased Rp. However, during the long-term immersion corrosion, the corrosion resistance of NAB alloys deteriorated with the increase of plastic deformation. This is because larger plastic deformation brought about higher internal stress in corrosion product film, which resulted in the premature peeling of the film and the loss of its protective effect on the alloy substrate.

Tensile plastic deformations were found to cause a decline in the corrosion resistance of NAB. And the mechanism was clarified from the evolution of corrosion products during the corrosion process.

The purpose of this study is to optimize and improve conventional welding using EMF assisted technology. Current industrial production has put forward higher requirements for welding technology, so the optimization and improvement of traditional welding methods become urgent needs.

External magnetic field assisted welding is an emerging technology in recent years, acting in a non-contact manner on the welding. The action of electromagnetic forces on the arc plasma leads to significant changes in the arc behavior, which affects the droplet transfer and molten pool formation and ultimately improve the weld seam formation and joint quality.

In this paper, different types of external magnetic fields are analyzed and summarized, which mainly include external transverse magnetic field, external longitudinal magnetic field and external cusp magnetic field. The research progress of welding behavior under the effect of external magnetic field is described, including the effect of external magnetic field on arc morphology, droplet transfer and weld seam formation law.

However, due to the extremely complex physical processes under the action of the external magnetic field, the mechanism of physical fields such as heat, force and electromagnetism in the welding has not been thoroughly analyzed, in-depth theoretical and numerical studies become urgent.

There is coupling between the branches of mobile parallel robots, similar to traditional parallel mechanisms, but there is currently relatively little research on the coupling problem between the branches of mobile parallel robots.

This study optimizes the coupling analysis method of traditional parallel mechanisms, treats the mobile parallel mechanism as a whole, takes the motion of the active pair as input and the overall motion of the mobile parallel mechanism as output and analyzes the input–output characteristics of the mobile parallel mechanism. Moreover, this study applies this theory to a mobile parallel mechanism, designs control logic and finally conducts simulation and physical verification.

This study proposes a coupling analysis method suitable for parallel mobile robots and designs the control logic of their active pair based on the results of their coupling analysis. This study designs a multimode variable coupling parallel mobile robot, which can change the coupling of the mechanism by changing its own branch chain structure, so that it can switch between different coupling configurations to meet the different needs brought by different terrains.

The work presented in this paper propose a method for analyzing the coupling of mobile parallel robots and simplify their control logic by applying coupling theory to the design of mobile parallel robots. This study conducts simulation and physical experiments, thereby filling the gap in the coupling analysis of parallel mobile robots and laying the foundation for the research of uncoupled parallel mobile robots.

This paper aims to clarify the impact of information asymmetry on users' payment rates and examine the role of perceived uncertainty (PU) and acceptable price (AP) in the relationship between information asymmetry and users' payment rates.

To test the influences of information asymmetry on users' payment rates, this paper collects 18,489 transaction data from the Chinese knowledge payment platform Zhihu with a Python crawler. This paper constructs a mediation model to define the relationship between information asymmetry and users' payment rates by introducing PU and AP as the mediators.

Information asymmetry negatively affects users' payment rates. In addition, PU and AP mediate the information asymmetry in users' payment rates bond.

This study only explores the mediators of the information asymmetry users’ payment rates bond, ignoring the effect of potential moderators, which would be an important direction for future research.

The findings of this paper suggest that information communication is essential in knowledge market transactions. Knowledge providers, as well as knowledge platforms, should enhance information exchange with consumers in order to increase product sales.

This paper provides a new perspective for understanding how information asymmetry affects users' payment rates and helps to guide suppliers to improve product quality. The research framework of this paper is universal to a certain extent.

This paper is one of the first to propose using PU and AP to construct a mediation model to study the information asymmetry between users' payment rates relationship. It provides a new perspective for understanding the channel of information asymmetry in customer behavior.

This study aims to using Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning electron microscope/energy dispersive Xray spectrometer to identify different automotive coatings for forensic purpose.

Two four-layered samples in a hit-and-run case were compared layer by layer with three different methods. FTIR spectroscopy was used to primarily identify the organic and inorganic compositions. Raman spectrum and scanning electron microscope/energy dispersive Xray spectrometer (SEM-EDS) were further used to complement the FTIR results.

Two weak and tiny peaks in one layer found between two samples by FTIR, Raman microscope and SEM-EDS verified the result of differences. The study used the three instruments in combination and found it’s effective in sensing coatings, especially in the inorganic additives.

Using these three instruments in combination is more accurate than individually in multilayered coating analysis for forensic purpose.

The three different instruments all present unique information on the composition, and provided similar and mutually verifiable results on the two samples.

With this method, scientists could identify and discriminate important coating evidences with tiny but characteristic differences.