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The purpose of this paper is to propose a novel method to prepare pure Ti powder for 3D printing with tailorable particle size distribution.

The main procedures of the present method consist of gas state reaction to synthesize TiH₂ nanoparticles, agglomeration to obtain micronscale powder particles by spray drying, and densification of particle interior by heat treatment.

The prepared Ti powder has a specific bimodal particle size distribution in a range of small sizes, good sphericity and high flowability. Particularly, this new technique is capable of controlling powder purity and adjusting particle size.

To the best knowledge of the authors, the approach for preparing 3D printing metallic powders from nanoparticles has not been reported in the literature so far. This work provides a novel method that is particularly applicable to prepare 3D printing metallic powders which have small initial particle sizes and high reactivity in the air.

This paper intends to provide a thematic literature review of the scholarly research articles orbiting the Sino–African education cooperation and exchange, published between 2005 and 2022.

The methodology used in this paper is qualitative in nature with a thematic approach. The author used content analysis techniques to spotlight the major themes of the topic studied. The author selected the papers and theses, based on their heuristic capacity, from two major databases for the English and Chinese literature: Web of Science and CNKI. The selection process resulted in 60 high-quality peer-reviewed articles and theses. Another 30 research articles and theses were used as supplementary resources.

The literature concentrates on six points: the historical development, the nature of the exchange, the frameworks of the cooperation, vocational training and knowledge transfer, African students in China and their experiences, and education cooperation and soft power. However, research tends to be somewhat polemical rather than an academic debate between Chinese researchers and their western peers. Therefore, empirical studies beyond the geopolitical preoccupations and the “YEA” or “NAY” to the Sino–African education exchange are critically needed.

The implications of this study go beyond the east/west or developed/developing world rhetoric and focus more on sustainable educational development on a global scale. Understanding how the literature on the Sino–African education engagement is shaping, provides valuable insights into international education in the global south. It can also be implied to approach educational engagement with other destinations such as India, Türkiye and Brazil.

This thematic literature review concentrates on the educational aspect of Sino–African relations. It compares English and Chinese peer-reviewed scholarly articles and theses on China–Africa educational engagement and has heuristic implications for sustainable educational development globally.

To use the 4H-SiC material in integrated circuits for high temperature application, an accurate and simple circuit model of n-channel planar 4H-SiC MOSFET is required.

In this paper, a SPICE model of n-channel planar 4H-SiC MOSFET was built based on the device simulation results and measurement results. Firstly, a device model was simulated with Sentaurus TCAD, with measured parameters from fabricated planar 4H-SiC MOSFET previously. Then the device simulation results were analyzed and parameters for SPICE models were extracted. With these parameters, an accurate SPICE model was built and simulated.

The SPICE model exhibits the same performance as the measured results with different environment temperatures. The simulation results indicate that the maximum fitting error is 0.22 mA (7.33% approximately) at 200 °C. A common-source amplifier with this model is also simulated and the simulated gain is stable at different environment temperatures.

This paper provides a reliable modeling method for n-Channel Planar 4H-SiC MOSFET and reference value for the design of 4H-SiC high temperature integrated circuit.

This paper aims to investigate the influence of laser energy density on microstructure and mechanical properties of the selective laser melted (SLMed) Ti6Al4V to complement the existing knowledge in additive manufacturing of Ti6Al4V for future application of selective laser melting (SLM) in fabricating Ti6Al4V parts.

Ti6Al4V alloy is fabricated by SLM by adopting various energy densities. Microstructures and mechanical properties of the Ti6Al4V deposited using different energy densities are characterized.

Both high relative densities and microhardness can be obtained in the optimized processing window. The decrease of martensite width and spacing can improve the microhardness on both XOY and XOZ sections when the applied E_V (defined as the laser energy per unit volume) increases. The width of the columnar grain increases with E_V, resulting in a stronger anisotropy in microhardness between XOY and XOZ sections. Residual tensile stresses exist in the SLMed Ti6Al4V and increase with an increasing E_V. A tensile strength of 1,268 MPa, a yield strength of 1,030 MPa, and an elongation of 4% can be obtained by using the optimized range of E_V.

The microstructure of SLMed Ti6Al4V is quantitatively analysed by measuring the size of columnar grains and the martensites. The anisotropy of microstructures and properties in SLMed Ti6Al4V is characterized and its dependence on laser energy density is established. The residual stress in SLMed Ti6Al4V is characterized and its dependence on laser energy density is established. An optimized processing window to deposit Ti6Al4V alloy by SLM is proposed.

With respect to the multiple-attribute decision-making problem with subjective preference for a certain attribute whose weight-value range have been given over other attributes whose weight values are unknown, a method based on the mean value of the grey number is proposed to analyse the decision-making problem. This method is used to choose a supply-chain partner under the condition that the decision makers have a preference for a certain attribute of various alternatives. The paper aims to discuss these issues.

First, the middle value of the preferred attribute’s weight-value range is supposed to be its weight value according to the content of the mean value of the grey number. Second, to reflect the decision maker’s subjective preference information, an improved optimisation model that requests the minimum deviation between the actual and expected numerical value of each attribute is constructed to assess the attributes’ weights. Third, the correlated degree and the correlation matrix, which are determined by the weight values of all attributes, are used to rank all the alternatives.

This paper provides a method for making a decision when decision makers have a preference for a certain attribute from an array of various alternatives, and the range of the certain attribute’s weight value is given but the weight value of the other attributes is unknown. When applied to supply-chain partner selection, this method proves feasible and effective.

This method is feasible and effective when applied to supply-chain partner selection, and can be applied to other kinds of decision-making problems. This means it has significant theoretical importance and extensive practical value.

Based on the mean value of the grey number, an optimisation model is built to determine the importance degree of each attribute, then the correlated degree of each alternative is combined to rank all the alternatives. This method can suit the decision makers’ subjective preference for a certain attribute well.

The purpose of this paper is to revisit and update Palmer and Choi (2014), which conducted a descriptive literature review on open source software (OSS) studies published by the end of February 2013 in the library context.

The same article search and filtering procedures used in Palmer and Choi (2014) were used, resulting in a total sample size of 105 articles. These articles were then examined based on the same six variables (i.e. publication year, publication outlet, software type, article type, library type and article topic) from Palmer and Choi (2014) along with two new variables (i.e., study country and prolific authors).

The volume of research articles was found to be in a downwards trend since 2010. As suggested by Palmer and Choi (2014), survey research increased and was found to be the second most popular article type. Regarding library types, the proportion of articles in the context of academic and research libraries was found to have expanded even further. As to article topics, perceptions, which investigates users’ (or non-users’) various perceptions towards OSS, was newly added and was ranked fourth. Given the maturity of the research stream, two new variables (i.e., study country and prolific authors) were examined, and the findings from analyzing them are also presented.

By examining library OSS articles published between March 2013 and February 2022, this study uncovers changes and developments in the research since Palmer and Choi (2014), which provides a picture of where the research stands now with several updated and new implications.

The purpose of this paper is to examine whether the presence of returnees serving on the audit committee affects auditor choice in emerging markets.

Using a logistic model, this study tests the relationship between the presence of returnees in the audit committee and auditor selection and how this relationship varies with the level of agency costs. The authors also perform several other additional analyses to ensure the robustness of the results, including propensity score matching, Heckman’s two-stage model and change analysis.

Using A-share listed companies in China from 2008 to 2016, the authors find a positive association between the presence of audit committee returnees and a demand for high-quality auditors and such association is strengthened in firms with a higher level of agency costs. The authors further find that discretionary accruals and the incidence of financial restatements are lower in firms with audit committee returnees.

Although this study focuses on audit committee members with foreign study or foreign work experience, it remains to be seen if similar effects could be achieved through foreign ownership or work experience with foreign customers or suppliers.

This study provides evidence on a new channel of international knowledge spillover through which the emigration of talent increases board monitoring by demanding high-quality auditors in an emerging economy.

Reducing employees’ knowledge hiding is vital for enterprise managers. The development of enterprise social media brings opportunities for them to manage employees’ knowledge-hiding behaviors. However, whether the use of enterprise social media inhibits or promotes knowledge hiding is still unclear. The purpose of this study is to explore how enterprise social media usage affect employees' knowledge hiding.

Based on the intrinsic and extrinsic motivation model, this paper proposes a research model to investigate the relationship between enterprise social media usage and knowledge hiding, using a structural equation modeling analysis of 288 employees’ data.

The results show that work-related public social media usage has an inhibiting effect on employees’ knowledge hiding, whereas the effect of work-related private social media usage on employees’ knowledge hiding is not significant; socially related public social media and private social media usage has a promoting effect on employees’ knowledge hiding; and job engagement acts in a positive moderating role between socially related private and public social media usage and evasive hiding.

First, this paper contributes to knowledge-hiding literature by revealing the relationship between enterprise social media usage and knowledge hiding. Second, this study contributes to motivation theory by clarifying how the use of enterprise social media with different motivations affects knowledge hiding. Third, this paper also contributes to knowledge-hiding literature by revealing a boundary condition, namely, job engagement.

The purpose of this paper is to propose a method for solving nonlinear fractional partial differential equations on the semi-infinite domain and to get better and more accurate results.

The authors proposed a method by using the Chebyshev wavelets in conjunction with differential quadrature technique. The operational matrices for the method are derived, constructed and used for the solution of nonlinear fractional partial differential equations.

The operational matrices contain many zero entries, which lead to the high efficiency of the method and reasonable accuracy is achieved even with less number of grid points. The results are in good agreement with exact solutions and more accurate as compared to Haar wavelet method.

Many engineers can use the presented method for solving their nonlinear fractional models.

High residual stress caused by the high temperature gradient brings undesired effects such as shrinkage and cracking in selective laser melting (SLM). The purpose of this study is to predict the residual stress distribution and the effect of process parameters on the residual stress of selective laser melted (SLMed) Inconel 718 thin-walled part.

A three-dimensional (3D) indirect sequentially coupled thermal–mechanical finite element model was developed to predict the residual stress distribution of SLMed Inconel 718 thin-walled part. The material properties dependent on temperature were taken into account in both thermal and mechanical analyses, and the thermal elastic–plastic behavior of the material was also considered.

The residual stress changes from compressive stress to tensile stress along the deposition direction, and the residual stress increases with the deposition height. The maximum stress occurs at both ends of the interface between the part and substrate, while the second largest stress occurs near the top center of the part. The residual stress increases with the laser power, with the maximum equivalent stress increasing by 21.79 per cent as the laser power increases from 250 to 450 W. The residual stress decreases with an increase in scan speed with a reduction in the maximum equivalent stress of 13.67 per cent, as the scan speed increases from 500 to 1,000 mm/s. The residual stress decreases with an increase in layer thickness, and the maximum equivalent stress reduces by 33.12 per cent as the layer thickness increases from 20 to 60µm.

The residual stress distribution and effect of process parameters on the residual stress of SLMed Inconel 718 thin-walled part are investigated in detail. This study provides a better understanding of the residual stress in SLM and constructive guidance for process parameters optimization.