Search results

With respect to severe working conditions such as heavy load and impact, this paper aims to investigate the friction reduction and anti-wear performance of kaolin and molybdenum dialkyl dithiophosphate (MoDDP) composite lubricant additives to improve the lubrication effect of a single additive.

A four-ball friction test was carried out to determine the optimal concentration of kaolin and organic molybdenum additives and the tribological properties of the kaolin/MoDDP composite lubricant additives. A ring block test of composite lubricant additives was designed to investigate its lubrication performance under the severe working conditions of low speed, heavy load and impact.

The results showed that the optimal addition mass fractions of kaolin and MoDDP were 4.0 and 1.5 Wt.%, respectively, when kaolin and MoDDP were used as single lubricant additives. Compared with the single additive, the 4.0 Wt.% kaolin/1.5 Wt.% MoDDP composite lubricant additive showed excellent friction reduction and anti-wear effects under heavy load and impact conditions. Physicochemical analysis of the wear surface revealed that the lamellar kaolin additive and MoDDP had excellent synergistic effects, and the friction process promoted the generation of lubricant films containing a chemically reactive layer of MoS₂, MoO₂, FeS₂ and Fe₂O₃ and a physically adsorbent layer containing SiO₂ and Al₂O₃, which play important roles in anti-wear and friction reduction.

The excellent friction reduction and anti-wear effects of lamellar silicate minerals and the excellent antioxidant properties and good synergistic effects of molybdenum were comprehensively used to develop the composite additives with great lubricating properties.

High-silicon chromium iron (HSCI) has been used in ground grids in southern China, while there was a lack of study on its corrosion behavior in this soil environment. The purpose of this paper is to discover the corrosion of HSCI in acidic and alkaline soil solutions.

The original defects on the HSCI surface were observed using optical microscopy, and the corrosion behavior of the HSCI in the acidic and alkaline soil solutions were jointly detected using electrochemical measurements and scanning electron microscopy/energy dispersive spectrometer.

The results showed the corrosion rates of the HSCI in the acidic and alkaline soil solutions were limited, and the high contents of Cr and Si in matrix was responsible for its high corrosion resistance. The HSCI showed a similar corrosion tendency in the two solutions, while its corrosion rate in the acid soil solution was higher than that in the alkaline soil solution. The corrosion pits on the specimen surface were originated from the original defects in matrix, and the edges of the corrosion pits were more rounded than the original defects after 720 h immersion in the two solutions. The original defects in the HSCI matrix played a significant role in the corrosion process.

The paper discovered the corrosion evolution of HSCI in the acidic and alkaline soil solutions. What is more, the acceleration role of the original defects on the corrosion of the HSCI in the acidic and alkaline soil solutions was discovered in the paper. The results are beneficial for the material selection of ground grid equipment in engineering.

This study aims to clarify the direct impact of digitalization on export performance (EP) by synthesizing previous research and testing this relationship empirically. Furthermore, the study investigates digitalization types, contextual moderators and method moderators affecting the impact of digitalization on EP.

The study uses meta-analysis to test the digitalization–EP relationship (k = 81) using data from 106 independent samples involving 62,082 respondents across nearly 30 countries.

The study finds digitalization’s positive and significant effect on EP (r = 0.36). The impact of digitalization on EP is also subject to different moderators, including digitalization type (i.e. digital capabilities), contextual factors (i.e. institutions, export experience, development of the region and industry) and method factors (i.e. back translation and strategy measurement).

Scholars have initiated studies on the impacts of diverse digitalization types on EP, while empirical findings on these effects remain inconclusive. Based on resource-based theory, the study develops and validates a comprehensive meta-analytic framework, revealing the important influence of digitalization on EP. The moderator findings further highlight the impact of internal and external contingencies on the outcomes of exporting firms’ digitalization.

In response to increasing demand for a fully customized and individualized home environment, mass customization (MC) has been suggested as an effective strategy to fulfill the customer’s customization needs while keeping production cost-effectiveness. However, in current practice, the implementation of the MC in the industrialized housing industry has not achieved an ideal level. Little effort was devoted to customer value generation and achieving lean production in a multi-disciplinary MC environment. In this concern, a highly efficient and flexible production information system is expected to capture accurately the customer’s demand and efficiently perform work planning for encouraging customer involvement and mass efficiency production.

To gain an insight into the development of the MC production information system for the housing industry and to depict the interaction among system modules, this study used a design science research methodology for a case study of customized cabinet production information system development.

A prototype of the production information system was proposed in this paper, supported by three information technologies to facilitate the MC implementation in the millwork manufacturer. A focus group discussion method was carried out for evaluating the system feasibility and the subsequent survey analysis on the virtual reality (VR) interface experiment. The evaluation process results showed that the VR interface is an effective medium for design information communication and encourages customer involvement. Most participants believed that the proposed production information system could generally benefit the MC implementation and improve production efficiency.

This study integrated lean production principles along with building information modelling, VR and discrete-event simulation in the production information system to assist the manufacturer in effectively handling variant product information and enabling quicker reactions in response to diverse customer requirements in housing industries. The coordination among system modules and the managed information flow could be a valuable reference for future MC production system development in housing industries.

This paper systematically reviews and scrutinises the current development of studies concerning digital platform use in firms’ internationalisation. It also provides a research agenda for future work. Despite more than two decades of research, the study of how traditional firms enter foreign markets using digital platforms remains in its infancy. This paper contributes insights into the academic and managerial relevance of this field.

A systematic review of the literature based on content analysis was undertaken, drawing from peer-reviewed journal articles in international business, international marketing, information systems, and electronic commerce. The articles were published between 1999 and 2023, and the review employed a vote-counting method.

This analysis of 61 papers indicates that research on digital platform use in firms’ internationalisation is growing rapidly. However, the field itself is fragmented, and the research findings are inconsistent. This dynamic area reflects a growing trend, is dominated by several theories, relies primarily on survey data, and frequently uses China as a research context.

In acknowledging the vibrancy and managerial importance of this field, the authors offer a comprehensive overview of the existing studies to serve as a repository of knowledge on digital platform use in internationalisation for both academics and practitioners. Based on the aforementioned analysis, this study develops a reconciling framework to address current research gaps and identify future study directions.

This paper aims to study the influence of different seal structure parameters and working conditions on the air-oil two-phase flow characteristics and leakage characteristics of the seal cavity in the bearing cavity of the aero-engine spindle bearing tester.

In this paper, the VOF method and RNG k-ε turbulence model are used to explore the flow characteristics and leakage characteristics of the labyrinth seal cavity of an aero-engine spindle bearing tester under the condition of air-oil two-phase flow.

The distribution of the lubricating oil is related to the sealing clearance and the air-oil ratio. The amount of oil leakage increases with increasing of sealing chamber clearance, air-oil ratio and inlet velocity and decreases with increasing curvature and speed. The amount of air leakage increases with sealing clearance and inlet velocity.

In comparison to the pure air-phase flow field, the air-oil two-phase flow field can more accurately simulate the lubricating oil flow in the sealing chamber.

Drawing on the resource-based view and institutional theory, this study explores how firms select export channels to realise the value of their product development capabilities (PDC) and improve export performance by aligning PDC, entrepreneurial orientation (EO), cultural-cognitive institutional distance (CCID) and channel selection.

This study adopted a quantitative design and used data collected from multiple respondents in 294 Chinese exporting ventures. Hypotheses were tested using logistic regression analysis and multiple regression analysis.

The results of the study suggest that PDC plays a vital role in export channel decisions. The results also show that there is a three-way interaction between PDC, EO and CCID regarding export channel selection. More importantly, this study suggests that firms using export channels that align with PDC, contingent on EO and CCID, generate superior export performance.

This study extends the export channel literature by looking at the different roles of important organisational capabilities (i.e. PDC and EO) on export channel selection. Further, it shows that firms need to align the exploitation of their PDC with the export channel selection, along with EO capabilities, and CCID to achieve better performance in the export market.

Stab-resistant body armor (SRBA) can protect the human body from injury as a result of stabbing by sharp projectiles. However, in its current design SRBA, it has not been widely adopted for use, because of its weight and poor flexibility. Herein, this paper aims to detail a new type of SRBA that is inspired by the armor plating of mammals and is fabricated using laser sintering (LS) technology.

This new type of SRBA was fabricated using LS technology. The laser sintered SRBA was subjected to a stab resistance performance test that conformed to the GA 68-2008 Chinese National Standard. The stab resistance response of the novel structured, stab resistance test plates in this study was analyzed using the using the AUTODYN explicit module in ANSYS-Workbench.

The structure of the novel stab resistance plate was designed and the optimum structural parameters were tested, discussed and achieved. The mechanism of dissipation of the impact energy by the pyramidal structures of the novel SRBA was studied, and it was found that this structure dispersed the kinetic energy of the knife and minimized the structural damage to the plate. Interlinks inspired by the pangolin hierarchy structure were designed and used to fabricate a large piece of laser sintered body armor.

High-performance laser sintered stab resistance plate was produced via the material and structure studies, which could reduce 40 per cent weight on the stab resistance body armor and increase the wearability.

Consumers may boycott firms’ corporate social responsibility (CSR) activities, but little is known about when, why and how they would respond in this way. Based on psychological contract violation and discount principles, the purpose of this paper is to argue that timing and fit of CSR activities are the main dimensions of consumers’ psychological contract. It is posited that CSR activities would be boycotted if consumers perceived violation of their psychological contract, and their altruistic tendency would have a moderating effect on this mechanism.

This paper takes the form of an empirical study using a sample of 434 respondents through scene-questionnaire survey in central China.

It is found that (1) low fit or reactive CSR activities would induce consumers’ psychological contract violation, and the latter has a more significant influence; (2) perceived CSR is negatively related with consumers’ boycott behaviors, but CSR activities would be boycotted if consumers’ psychological contracts are violated; (3) the negative relationship between perceived CSR and consumers’ boycott behaviors would be strengthened by consumers’ altruistic tendency, and the positive relationship between consumers’ psychological contract violation and their boycott behaviors would also be strengthened by their altruistic tendency.

This paper has significant theoretical implications, as it answers the question that when, why and how CSR activities would be boycotted. Besides, it contributes to literature on psychological contract for applying it to CSR research field. Furthermore, the double-edged effect of consumers’ altruistic tendency extends literature on pro-social behaviors.

This paper is of interests to corporate management and academics who wish to understand when and why consumers would boycott CSR activities and the factors that would relax consumers’ negative responses.

This is the first paper that investigates when, why and how CSR activities would be boycotted from the perspective of consumers’ psychological contract violation.

A parametric method for designing the hub, casing and blades of the miniature centrifugal compressor impeller was developed. The relationship model of the size, aerodynamic and performance parameters of the centrifugal impeller was established. Based on the selected design parameters, the miniature centrifugal-type impeller was designed, and the work efficiency was calculated.

In this study, a micro-centrifugal compressor impeller with a diameter of less than 25 mm was designed. A parametric design method was developed, and the functional relationship between the geometric and gas fluidity parameters was established.

The results of this study showed that the performance parameters of the designed micro-centrifugal impeller satisfied the design requirements. The proposed method is useful as a reference for designing and analysing compressor impellers under high Reynolds number conditions.

A parametric design method was developed, and the functional relationship between the geometric and gas fluidity parameters was established. Under the Reynolds number conditions, the flow characteristics of the gas in the compressor were analysed; the shear-stress transport turbulence equation was solved using the finite volume method. In addition, the effects of the Reynolds number on the velocity, pressure, mass flow and efficiency of the micro-scale centrifugal compressor were evaluated. The results showed that the performance parameters of the designed micro-centrifugal impeller satisfied the design requirements. The proposed method is useful as a reference for designing and analysing compressor impellers under high Reynolds number conditions.