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The purpose of this paper is to study the mechanical and corrosion behaviors of selective laser melting (SLM) 30CrMnSiA steel.

The microstructure, mechanical behavior and corrosion resistance of SLM 30CrMnSiA steel were studied by electrochemical test and immersion experiment.

The results showed that the microstructure of SLM 30CrMnSiA steel contained equiaxed fine (25.0 µm) ferrite and lamellar pearlite. The tensile strength of SLM 30CrMnSiA steel under the process parameters is 1,447 MPa and the elongation is 7.5%. As the immersion/salt spray test time increased to 15 days/48 h, corrosion mainly occurred in the local position of the sample and corrosion resistance decreased. When the immersion/salt spray test time increased to 30 days/168 h, the corrosion production covered the surface of the samples and the corrosion resistance increased.

The paper can guide the application and in situ repair for low-alloy steel by additive manufacturing.

This research aims to establish an index system and a grey comprehensive evaluation model for analyzing the sustainability of urban tourism.

The sustainability evaluation of urban tourism is regarded as a multi-level and multi-index evaluation problem in this study. The evaluation index system of urban tourism sustainable development is constructed based on the ideas of holism and systems thinking. Then based on grey system correlation analysis theory, a new evaluation model is proposed to effectively solve the complex and uncertain problems in the sustainability evaluation system of urban tourism. An actual example of the five cities (Nanjing, Zhenjiang, Changzhou, Wuxi and Suzhou) in Southern Jiangsu Province of China is adopted to demonstrate the feasibility and practicability of the proposed model.

The grey comprehensive evaluation model can effectively convert the complex indices into comprehensive optimal membership degrees which are easy to be understood. The empirical study on the urban tourism sustainable development of South of Jiangsu found that: Suzhou, Nanjing and Wuxi were in the basic stage of sustainable development; Changzhou and Zhenjiang were in the preliminary stage of sustainable development. The social responsibility fulfillment of urban tourism in five cities fails to reach a satisfactory level, especially Zhenjiang and Changzhou remain in a low level in fulfillment of social responsibility.

Due to the difficulty of data collection, the authors can only use the data on 2010 to do a static evaluation in this study. If the authors can have more data on different years, it is feasible to develop a dynamic evaluation model to analyze the evolution law of the sustainability of urban tourism.

The evaluation results provide the necessary support to assist the tourism management departments of the five cities with their policy making.

This study not only supplements the evaluation modelling methods widely used in the area of tourism management, but also promotes the development of the grey systems theory itself.

The purpose of the paper is to disclose the effect of the relative position (d) between the impeller and non-vane cavity on the hydraulic performance and unsteady characteristics of vortex pump.

Three groups of vortex pump models with different impeller installation positions were analyzed and studied by combining experimental and CFD (Computational Fluid Dynamics) numerical calculations.

The steady numerical results show that as the width (d) of the impeller moves into the non-vane cavity increases, the proportion of circulation flow in the non-vane cavity is reduced and both the pump head and efficiency are on the rise. The unsteady numerical results and the Enstrophy analysis show that the dynamic and static interference between the circulation flow and the volute tongue is the main reason for the pressure pulsation with a frequency of 2fn in the vortex pump. With the increase of the d value, the dynamic and static interference between the circulation flow and the volute tongue is enhanced. The pulsation amplitude at the volute tongue of the d = 16.5 mm model increases about six times compared with the d = 0 mm model; the distribution of the vortex core in the non-vane cavity is closely related to the position of the impeller, and the peak of the Enstrophy of the circulation flow vortex belt always appears at the top of the impeller.

The research results provide a theoretical foundation for the optimization and improvement of the vortex pump.

The purpose of this paper is to study the influence of different cross-sectional shapes (rectangular, trapezoidal, oval and triangular) and layout forms of oil grooves (radial, circumferential, inclined, compound, helical and double-helical), and determine the optimal section shape and layout form of oil grooves on the temperature field.

Heat conduction theory model was established based on startup characteristics and friction heat principle of hydro-viscous clutch (HVC), and then the theoretical expression of angular velocity of the friction pair and control pressure were deduced, and the heat flux and its distribution on friction disk and separator disk were calculated. Finally, the finite element method was used to solve the temperature field of the friction pair.

The studies show that the circumferential oil groove got the highest temperature, and on the surface of all other structures, hot spots appear with different sizes and temperatures, and the maximum temperature difference in the friction zone is about 3°C, and in the oil groove zone is about 16°C, wherein the compound oil groove has the lowest average temperature. This research shows that the compound oil groove with rectangular cross-section is the best choice for the friction pair.

In this paper, it was found that the compound oil groove with rectangular cross-section is the best choice for the friction pair, and it provided a favorable theory reference and technical support for the structural design of the friction pair and optimized design of the high-power HVC.

In the era of digitalization, digital technology has transformed businesses and created enormous opportunities for organizations worldwide. Unsurprisingly, research on digital transformation has garnered significant interest among academics in recent decades. However, this study aims to recognize the key and holistic antecedents influencing digital transformation in manufacturing firms. This study also investigates the indirect relationships of antecedents with firm performance.

The hypothesis was investigated using the partial least squares structural equation modeling (PLS-SEM) approach. The data was collected from 279 employees through a self-administered survey of manufacturing firms.

The results described a significant and positive impact of competitive pressure, leadership role, organization culture, organization mindfulness, government regulation, and IT readiness on digital transformation and firm performance. Furthermore, digital transformation partially mediates the relationship between antecedents and firm performance.

The study finds a holistic perspective of the critical antecedents of digital transformation using the mediation role of digital transformation and moderating effects of firm agility. Additionally, all antecedents have a significant association with Firm Performance.

Despite the recent extending research on knowledge hiding, there is still scant research on social stressor phenomena-related contextual antecedent factors and new cognitive mechanisms of knowledge hiding behaviors. To shed new light on this unexplored gap, this research explores the multi-level moderated mediation model that examines how and when negative gossip experienced by targets in the workplace induces their knowledge hiding from coworkers drawing from the lens of social learning and cognitive theories. More specifically, this study aims to evaluate the relationship between negative workplace gossip and knowledge hiding via moral disengagement, and this mediation effect is also moderated by team relational conflict as a novel boundary condition.

This study collected multi-wave 338 employees’ data from 68 teams of cross-sectional industries in China, which were nested within teams. The collected nested nature data were analyzed by employing multi-level analysis based on hierarchical linear modeling.

The results suggested that negative workplace gossip first triggers moral disengagement and thereby, leads to knowledge hiding. Furthermore, the direct positive association between negative workplace gossip and moral disengagement was strengthened by increasing intra-team relational conflict. In addition, the mediation effect of moral disengagement between negative workplace gossip and knowledge hiding was also strengthened through increasing intra-team relational conflict.

This study first empirically examines the multi-level model using a new underlying mechanism (moral disengagement) and team-level boundary condition (relational conflict) and enriches the current literature on knowledge management and workplace gossip. Theoretical and practical implications of these findings and future research lines are also discussed, which will facilitate practitioners and academicians to curb counterproductive knowledge behavior.

The purpose of this paper is to use the viscosity of fluid to transmit power known as the hydro-viscous drive (HVD) to research the effect of two-phase flow on transmission characteristics.

In this paper, a 3D computational model of oil film between friction pair was built to study the transmission characteristics of a two-phase oil film, and the distribution contours of pressure and temperature of oil film were investigated using the computational fluid dynamics technology.

The finding of the paper suggests that the distribution law of pressure and temperature of two-phase oil film is almost linear along the radial direction. However, since the physical phenomena near the outlet of the oil film are entirely different, there exists fluctuation. Meanwhile, the volume fraction of air was obtained at different rotation speeds, and the maximum value is 10.55 percent. Compared to the single-phase oil film, the torque transferred by the oil film is not linear with the rotation speed, its value decreases gradually.

This paper’s conclusions are very important for the study of HVD and its applications, which provide a new idea to further study the mechanism of oil film transmission and its cavitation. The development of fluid viscous speed clutch is dedicated to a large industrial fan and water pump speed regulation and energy saving. With the successful application of the technology, it will have more wide applications in different fields, such as, in steel, water, petrochemical, power plant of slag pump and exhaust fan.

The purpose of this paper is to study the influence of the processing parameters of diamond wire sawing on surface morphology and roughness.

First, a wire saw cutting model is established to determine the positional relationship between a wire saw and the machined surface of the workpiece, and the abrasive grain cutting trajectory is generated. Through the data processing of the cutting trajectory, the simulation of the three-dimensional surface topography of the slice and the calculation of the surface roughness are realized by using the GUI programming of MATLAB. Finally, different surface roughness values are obtained by changing the machining parameters (saw wire speed and workpiece feed speed).

The conclusion is that the surface roughness of the slice is larger when the feed speed is higher and smaller when the linear speed is higher.

Diamond wire saw cutting is the first process of chip processing, and its efficiency and quality have an important impact on subsequent processing. This paper will focus on the influence of the sawing wire cutting processing parameters (sawing wire speed and workpiece feed speed) on the surface roughness to optimize the processing parameters and obtain smaller surface roughness values. Through MATLAB three-dimensional simulation, the surface morphology can be observed more intuitively, which provides a theoretical basis for improving the processing quality.

The paper investigates the mediation role of external integration in the relationship between internal integration and small and medium enterprises (SMEs) performance. Information and communication technology (ICT) was used to moderate the relationship between internal and external, and external integration and SMEs performance.

Cross sectional method was used to distribute questionnaires to owners of SMEs in Abossey Okai business enclave to assess the various dimensions in the study. Structural equation modeling was employed to assess the relationship among the dimensions, based on 163 validated questionnaires. Analysis of Moment Structures (Amos) and Statistical Package for Social Sciences (SPSS) were used in analyzing the data.

The results indicate that, external integration mediated the relationship between internal integration and SMEs performance. In addition, ICT had positive moderating effect in the relationship between internal and external integration, and external integration and SMEs performance.

Practically, this research informs owners and managers of SMEs to appreciate the importance of developing internal structures of a firm and further linking their operations with external partners. Additionally, findings will aid managers’ and owners’ leverage on ICT capabilities to enhance performance in their operations.

Engaging external integration to mediate the relationship between internal integration and SMEs performance and extending the relationship to include moderating role of ICT in both relationship that is internal and external integration on one side, and external and firm performance, the current study contributes to supply chain integration (SCI) and ICT available literature.

Accurately, positioning is a fundamental requirement for vision measurement systems. The calculation of the harvesting width can not only help farmers adjust the direction of the intelligent harvesting robot in time but also provide data support for future unmanned vehicles.

To make the length of each pixel equal, the image is restored to the aerial view in the world coordinate system. To solve the problem of too much calculation caused by too many particles, a certain number of particles are scattered near the crop boundary and the distribution regularities of particles’ weight are analyzed. Based on the analysis, a novel boundary positioning method is presented. In the meantime, to improve the robustness of the algorithm, the back-projection algorithm is also used for boundary positioning.

Experiments demonstrate that the proposed method could well meet the precision and real-time requirements with the measurement error within 55 mm.

In visual target tracking, using particle filtering, a rectangular is used to track the target and cannot obtain the boundary information. This paper studied the distribution of the particle set near the crop boundary and proposed an improved particle filtering algorithm. In the algorithm, a small amount of particles is used to determine the crop boundary and accurate positioning of the crop boundary is realized.