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The purpose of this paper is to establish a three-dimensional flow field model of the Invar alloy laser–metal inert gas (laser–MIG) hybrid welding process to investigate the influence of different heat sources between different layers and to analyze the flow field based on the two different heat source models for the multilayer welding.

The Invar steel plates with 19.5 mm thickness are welded into three layers’ seam using the hybrid laser–MIG welding technology. The flow field based on different heat source models is studied and then used to investigate the influence of different heat sources in different layers during the laser–MIG hybrid welding process. The simulation results of flow field using two different heat source models are compared with experiments.

The flow field simulations results show that using the Gaussian rotating body heat source model to simulate the temperature field is more consistent with the experiment of the hybrid laser–MIG welding where its flow field between different layers better reflects the characteristics of the hybrid laser–MIG welding.

The findings will be useful in the study of a variety of thick-plate laser–MIG hybrid welding process fluid flows.

In order to develop high shape retention yarn and investigate the effects of spinning process and core yarn contents on the shape retention of yarn, in this paper, three kinds of yarns, JC/T400 18.5tex (55.6dtex) core-spun yarn, JC/T400 18.5tex (44.4dtex) core-spun yarn and JC18.5tex pure cotton yarn were spun by using the complete condensing Siro-spinning technology. The paper aims to discuss these issues.

In this paper, the core-spun yarns were spun by using the complete condensing spinning and Siro-spinning technology. Two key spinning processes, yarn twist factor and core yarn pre-draft ratio, were optimized by using the orthogonal test method first. Then, via the variable control method, the position of the core yarn, the position of the bell mouth and the center distance between two bell mouths were optimized, respectively, and corresponding optimal spinning process of the three yarns was determined. Finally, the yarns were spun under the optimal process, and the performance of the spun yarns was tested and compared.

Results show that the yarn twist factor affects yarn strength and hairiness, the position of bell mouth affects the evenness and hairiness of the yarn mainly, and the position of the core yarn affects the coverage and hairiness of the yarn. For the Z-twist spinning, the core yarn enters the front roller from the left side of two strands center, which is beneficial to improve the covering effect of core yarn, and reduce the pilling phenomenon of the yarn. The contents of core yarn affect indicators of the yarn shape retention, such as yarn strength, elastic recovery and abrasion resistance.

The shape retention of yarns affects the shape retention of fabrics, and the production of yarn with high shape retention is a key step in achieving shape retention of fabrics. At present, there are little studies on the shape retention of yarns, most researchers shave focused on shape retention of fabrics. Using the complete condensing Siro-spinning method to spin the core-spun yarn can improve the quality of the yarn. Compared with traditional ring-spinning yarns, the addition of the core yarn can improve the shape retention of the yarn.

This paper aims to describe a three-dimensional mathematical and numerical model based on finite volume method to simulate the fluid dynamics in weld pool, droplet transfer and keyhole behaviors in the laser-MIG hybrid welding process of Fe36Ni Invar alloy.

Double-ellipsoidal heat source model and adaptive Gauss rotary body heat source model were used to describe electric arc and laser beam heat source, respectively. Besides, recoil pressure, electromagnetic force, Marangoni force, buoyancy as well as liquid material flow through a porous medium and the heat, mass, momentum transfer because of droplets were taken into consideration in the computational model.

The results of computer simulation, including temperature field in welded plate and velocity field in the fusion zone were presented in this article on the basis of the solution of mass, momentum and energy conservation equations. The correctness of elaborated models was validated by experimental results and this proposed model exhibited close correspondence with the experimental results with respect to weld geometry.

It lays foundation for understanding the physical phenomena accompanying hybrid welding and optimizing the process parameters for laser-MIG hybrid welding of Invar alloy.

Social shopping website (SSW) introduce the social side into the shopping process, thus making “window” shopping or browsing more interesting for customers. The purpose of this paper is to investigate customer online browsing experience and its antecedents (i.e. information quality and social interaction) and consequences (i.e. urge to buy impulsively and continuous browsing intention) in the context of SSW.

A survey questionnaire was distributed to visitors of online SSW to collect data, and partial least squares technology was used to test the research model.

The results of this study reveal that three types of web browsing, namely, utilitarian browsing, hedonic browsing and social browsing, take place in a SSW. The unique factors of SSW, namely, the quality of user generated contents and social interaction are critical for facilitating customers’ browsing experiences. Furthermore, the findings reveal that hedonic browsing experience is found to be the most salient factor influencing customers’ urge to buy impulsively and continuance intention.

The findings suggest that practitioners, such as designers and managers of SSW should give special attention to the benefits of browsing activity to convert web browsers into impulse purchasers and increase customers’ loyalty. Moreover, they should focus on improving the quality of user generated content and pay more attention to support and encourage social interaction to enhance browsing experiences on a SSW.

Existing studies about browsing behavior mostly focus on traditional online e-commerce website. This study represents the first step toward understanding browsing activity on SSW. Moreover, prior studies mainly focused on utilitarian and hedonic browsing experience; however, there is a lack of research on social browsing experience. The current study attempts to fill this research gap.

Aluminum alloy is susceptible to chloride ion attack in sea water, resulting in pitting damage and hence serious security risks for the related applications. To improve the corrosion resistance of Al alloy, micro-arc oxidation (MAO) technology has been developed to produce a protective dense oxide layer on top of Al alloy. However, the mechanism of MAO-induced corrosion resistance is still not fully understood, particularly on local corrosion issue. This paper aims to focus on comprehensively studying the corrosion-resistance mechanism by a series of technologies.

The corrosion behavior of samples was studied by open circuit potential (OCP), potentiodynamic polarization (PDP), electrode impedance spectroscopy (EIS) and localized electrode impedance spectroscopy (LEIS) tests in NaCl solution.

The MAO-coated Al alloy shows a more positive corrosion potential and a higher corrosion current density compared to the untreated counterpart, indicating a significantly enhanced corrosion-resistance. The study of surface morphology and structure also suggest significantly enhanced corrosion-resistance due to the MAO treatment.

Based on the results, a new corrosion model was proposed to describe the influence of MAO treatment on the corrosion process and corrosion mechanism of Al alloy, providing insights on the design of the corrosion-resistance coating for metallic alloys in marine applications.

This paper aims to explore the direct effects of open innovation (OI) on firms’ innovative performance, and to examine the moderating effects of knowledge attributes, including knowledge distance, knowledge embeddedness and partner opportunism on this relationship.

Survey data of 247 samples from China were used to test the proposed model through hierarchical regression analysis.

The findings indicate that the dimensions of OI are positively related to innovative performance. The results also reveal that knowledge distance positively moderates the relationship between inbound OI and innovative performance, whereas knowledge embeddedness negatively affects that relationship. Knowledge embeddedness negatively affects the relationship between inbound OI and innovative performance, whereas knowledge distance positively moderates that relationship. Thus, a new finding is proposed that knowledge attributes could align effectively with specific OI type to achieve superior innovation outcomes. In addition, the empirical results suggest that partner opportunism plays a negative moderating role on the relationship between outbound OI and innovative performance.

The proposed view that a firm’s innovation outputs will be superior when its knowledge attributes effectively align with OI enriches studies of the OI context and expands the literature of both the resource-based view and the knowledge-based view. Furthermore, this study provides insights into how OI benefits can be influenced by external contexts from the perspective of partners’ opportunistic behaviour.

The purpose of this paper is to investigate oxidation and the Au‐Sn reaction of laser reflowed (LR) micro‐solder joints when different protective atmospheres were applied.

A N2 atmosphere at room temperature, 60°C, 100°C and 130°C, or an air atmosphere at room temperature were utilized in this study. The solder balls were composed of Sn‐2.0Ag‐0.75Cu‐3.0Bi, and 120 μm in diameter. The surface finish of one pad of the joints was 4.0 μm Au/0.1 μm NiFe/0.01 μm Ta, another pad was made of Cu plated with 3.0 μm Au. The laser reflow process time was controlled to within 10 ms. Auger Electron Spectroscopy (AES) was used to identify the oxidation condition of LR solder joints with or without protection from a N2 atmosphere at room temperature. The appearance and cross‐sections of the joints protected by a N2 atmosphere at different temperatures were evaluated using SEM analysis.

Oxidation of LR solder joints from an air atmosphere was extremely severe, and the surfaces of solder were rough as compared with joints protected by a N2 atmosphere. Au‐rich phases and needle‐like AuSn4 intermetallic compounds (IMCs) formed at the interfaces of the solder and the pads. As the temperature of the N2 atmosphere was increased above 100°C, almost all of the Au‐rich phases disappeared. More needle‐like AuSn4 IMCs formed at the interfaces, as compared with that in joints protected by a N2 atmosphere at room temperature and 60°C. In addition, the orientation of the IMCs had clearly changed.

The results may provide a guide for controlling oxidation and the Au‐Sn reaction of micro‐solder joints during the LR process, and improving the properties of joints between solder and pads with Au surface finishes, by regulating the protective atmosphere.

The purpose of this paper is to investigate the effect of typical morphologies of Au-Sn IMCs (intermetallic compounds) at the interfaces of solder and pads on shear properties of laser reflowed micro-solder joints.

Sn-2.0Ag-0.75Cu-3.0Bi (SnAgCuBi) solder balls (120 μm in diameter), pads with 0.1, 0.5, 0.9 or 4.0 μm thickness of Au surface finish, and different laser input energies were utilized to fabricate micro-solder joints with Au-Sn IMCs having different typical morphologies. The joints were performed by a shear test through a DAGE bond test system. Fracture surfaces of the joints were analyzed by scanning electron microscopy and energy-dispersive X-ray spectrometry to identify fracture modes and locations.

Morphologies of Au-Sn IMCs would affect shear properties of the joints remarkably. When needle-like AuSn4 IMCs formed at the interfaces of solder and pads, almost entire surfaces presented the manner of ductile fracture. Moreover, shear forces of this kind of solder joints were higher than those of joints without Au-Sn IMCs or with a nearly continuous/continuous Au-Sn IMCs layer. The reason was that the shear performance of the solder joints with needle-like AuSn4 IMCs was enhanced by an interlocking effect between solder and needle-like AuSn4 IMCs. As a nearly continuous or continuous Au-Sn IMCs layer formed, the fracture surfaces presented more character of brittle than ductile fracture. However, if an Au layer still remained under Au-Sn IMCs, the shear performance of the joints would be enhanced.

The results in this study can be used to optimize microstructures and shear properties of laser reflowed micro-solder joints.

The purpose of this study is to improve the dispersion of nanoserpentine modified with OA, KH550 and KH550/oleic acid in lubricating oil. The main aims are to analyze the influence of the dispersion and stability of nanoserpentine modified by different modifiers on the friction properties of lubricating oil.

The nanoserpentine particles obtained by ball-milling were modified by silane coupling agent KH550, OA and KH550/OA, respectively. The dispersity and stability of nanoserpentine in base lubricating oil were characterized by the absorbance value method, centrifuge precipitation rate method and static observation method. The MMU-5G screen display friction and wear tester was used to evaluate the tribological properties of C45E4/C45E4 friction pairs in corresponding lubricating oils. The surface morphology of the friction pairs was observed by scanning electron microscopy and energy dispersive spectroscopy.

The results showed that the dispersity and stability of nanoserpentine particles in lubricating oil were best modified by OA, followed by the KH550/OA and finally, the KH550. Nanoserpentine particles modified with oleic acid showed optimum tribological properties as lubricant additives.

This study can improve the dispersion stability of nanoserpentine particles in lubricating oil, increasing the antiwear and antifriction performance of lubricating oil, which has great significance in economic and military aspects.

This paper aims to investigate the causal inferences between mobile application adoption and changes in travelers’ purchasing behavior regarding services supported by the travel and tourism industry.

Using a quasi-experiment conducted by an airline, data sets from more than 10,000 travelers were collected, and hypotheses were tested using propensity score matching and difference-in-difference methods.

Mobile application adoption has a significant positive effect on the total purchasing frequency of services and a significant adverse effect on booking tickets in advance and purchasing frequency from self-owned websites. Besides, this finding also suggested that members or travelers who had high average purchases in the past tend to buy more air tickets on average after mobile application adoption, while the number of days to book tickets in advance and purchase auxiliary services declined after mobile application adoption. However, males purchased more auxiliary services via mobile applications.

The study is based on the causal effect of mobile application adoption on purchasing behavior. Nevertheless, the theoretical basis remains relatively weak. Furthermore, the underlying mechanisms that cause the changes in purchasing behavior via mobile applications need to be elucidated.

This study enriches the hospitality and tourism literature on mobile application adoptions, multichannel purchasing behavior and revenue management. First, a quasi-experimental design is used to verify a causal relationship between mobile applications’ adoption and travelers’ purchasing behavior in the travel and tourism industry. Second, this study adds to examining travelers’ multichannel purchasing behavior in the travel and tourism industry. Third, this work enriches the current literature that explores auxiliary services and revenue management in the travel industry.

Mobile application adoption significantly impacted the travel and tourism industry. Besides, To the best of the authors’ knowledge, this is one of the first empirical studies that examined changes in purchasing behavior due to mobile application adoption from the perspective of service type. The findings provide the first evidence of the impact of mobile application adoption on service purchasing in the travel industry.