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Aluminum alloy is considered an ideal material in aerospace, automobile and other fields because of its lightweight, high specific strength and easy processing. However, low hardness and strength of the surface of aluminum alloys are the main factors that limit their applications. The purpose of this study is to obtain a composite coating with high hardness and lubricating properties by applying GO–PVA over MAO coating.

A pulsed bipolar power supply was used as power supply to prepare the micro-arc oxidation (MAO) coating on 6061 aluminum sample. Then a graphene oxide-polyvinyl alcohol (GO–PVA) composite coating was prepared on MAO coating for subsequent experiments. Samples were characterized by Fourier infrared spectroscopy, X-ray diffraction, Raman spectroscopy and thermogravimetric analysis. The friction test is carried out by the relative movement of the copper ball and the aluminum disk on the friction tester.

Results showed that the friction coefficient of MAO samples was reduced by 80% after treated with GO–PVA composite film.

This research has made a certain contribution to the surface hardness and tribological issues involved in the lightweight design of aluminum alloys.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0427/

The study aims to the distribution rule of lubricating oil film of full ceramic ball bearing and improve its performance and life.

The paper established an analysis model based on the fluid–solid conjugate heat transfer theory for full ceramic ball bearings. The distribution of flow, temperature and pressure field of bearings under variable working conditions is analyzed. Meanwhile, the mathematical model of elastohydrodynamic lubrication (EHL) of full ceramic ball bearings is established. The numerical analysis is used to study the influence of variable working conditions on the lubricant film thickness and pressure distribution of bearings. The temperature rise test of full ceramic ball bearing under oil lubrication was carried out to verify the correctness of simulation results.

As the speed increased, the oil volume fraction in full ceramic ball bearing decreased and the surface pressure of rolling element increased. The temperature rise of full ceramic ball bearings increases with increasing speed and load. The lubricant film thickness of full ceramic ball bearing is positively correlated with speed and negatively correlated with load. The pressure of lubricating film is positively correlated with speed and load. The test shows that the higher inner ring speed and radial load, the higher the steady-state temperature rise of full ceramic ball bearing. The test results are in high agreement with simulation results.

Based on the fluid–solid conjugate heat transfer theory and combined with Reynolds equation, lubricating oil film thickness formula, viscosity temperature and viscosity pressure formula. The thermal analysis model and EHL mathematical model of ceramic ball bearings are established. The flow field, temperature field and pressure field distribution of the full ceramic ball bearing are determined. And the thickness and pressure distribution of lubricating oil film in the contact area of full ceramic ball bearing were determined.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0126/

To understand the service performance of full ceramic ball bearings under extreme working conditions and improve their service life, dynamic characteristic tests of full ceramic ball bearings under ultra-low temperature conditions were carried out by a low-temperature bearing life testing machine, and temperature rise and friction were measured under extreme low-temperature environment.

The heat-flow coupling model of bearing was established by CFD software, and the test results were further analyzed.

The results show that the temperature rise of the bearing is not obvious in the liquid nitrogen environment. With the increase of the chamber temperature, the lubrication state of the bearing changes, resulting in the temperature rise of the outer ring of the bearing. As the temperature of the test chamber increases, the friction force on the bearing increases first and then decreases under the action of multifactor coupling.

The research results provide test data and theoretical basis for the application of all-ceramic ball bearings in aerospace and other fields and have important significance for improving the service life of high-end equipment under extreme working conditions.

The research results provide test data and theoretical basis for the application of full ceramic ball bearings in aerospace and other fields and have important significance for improving the service life of high-end equipment under extreme working conditions.

The research results provide test data and theoretical basis for the application of full ceramic ball bearings in aerospace and other fields and have important significance for improving the service life of high-end equipment under extreme working conditions.

The research results provide test data and theoretical basis for the application of full ceramic ball bearings in aerospace and other fields and have important significance for improving the service life of high-end equipment under extreme working conditions.

The purpose of this paper is to study the effects of these major parameters, including layer thickness, deposition velocity and infill rate, on product’s mechanical properties and explore the quantitative relationship between these key parameters and tensile strength of the part.

A VHX-1000 super-high magnification lens zoom three-dimensional (3D) microscope is utilized to observe the bonding degree between filaments. A temperature sensor is embedded into the platform to collect the temperature of the specimen under different parameters and the bilinear elastic-softening cohesive zone model is used to analyze the maximum stress that the part can withstand under different interface bonding states.

The tensile strength is closely related to interface bonding state, which is determined by heat transition. The experimental results indicate that layer thickness plays the predominant role in affecting bonding strength, followed by deposition velocity and the effect of infill rate is the weakest. The numerical analysis results of the tensile strength predict models show a good coincidence with experimental data under the elastic and elastic-softened interface states, which demonstrates that the tensile strength model can predict the tensile strength exactly and also reveals the work mechanism of these parameters on tensile strength quantitatively.

The paper establishes the quantitative relationship between main parameters including layer thickness, infill rate and deposition velocity and tensile strength for the first time. The numerically analyzed results of the tensile strength predict model show a good agreement with the experimental result, which demonstrates the effectiveness of this predict model. It also reveals the work mechanism of the parameters on tensile strength quantitatively for the first time.

The purpose of this paper is to validate, distinguish, and integrate the multiple mechanisms linking leader-member exchange (LMX) to employee work effort. Taking a multi-foci perspective, the authors propose that organization-based self-esteem (OBSE), supervisory support, and organizational identification each explain unique variance in the LMX-work effort relationship.

The data were collected using a two-wave survey among 184 employees from a wide variety of professions, industries, and organizations. Multiple mediation tests and path analysis were conducted to examine the hypotheses.

The results suggested that when entered simultaneously, OBSE, supervisory support, and organizational identification each explained unique variance in the relationship between LMX at Time 1 and work effort at Time 2.

The research shows that leaders stimulate employee work effort via multiple foci. The mediating mechanisms of these foci are distinct and unique. It implies that researchers need to take the multiple foci of leadership into account when studying LMX.

Previous studies generally treat LMX as a dyadic construct; the study is among the first to reveal the multiple foci in LMX. By simultaneously examining mechanisms of the individual-, dyad-, and collective-foci, the research substantiates the unique effect of the three mechanisms, and integrates theories in LMX research. Moreover, the research in the Chinese context further validates the effectiveness of LMX in non-western culture, and provides contextual implications.

Literature has shown that phenolic acids and flavonoids are bearing with hypoglycemic and anti-adipogenic properties. Therefore, this study aims to evaluate the possibility of phenolic-rich soya bean husk powder extract (SHPE) in combating diabetes and obesity using in vitro models.

The hypoglycemic properties were evaluated by determining the ability of SHPE (25-100 µg/mL) in inhibiting a-amylase and a-glucosidase enzymes and in triggering insulin secretion in BRIN-BD11 cells. Murine 3T3-L1 adipocytes were used for evaluating the anti-adipogenic properties of SHPE through the determination of relative lipid accumulation, triglyceride content and glycerol-3-phosphate dehydrogenase (GPDH) activity.

The hypoglycemic properties of SHPE was in the dose-dependent manner, where 100 µg SHPE/mL exhibited a significant higher (p < 0.05) a-amylase inhibitory activity (56.8 ± 0.11 per cent) and insulin secretion activity (0.73 ± 0.02 µg/l) against other concentrations. In contrast to the aforementioned findings, a significant lower a-glucosidase inhibitory activity (52.0 ± 0.44 per cent) was also observed in 100 µg SHPE/mL. Nevertheless, findings revealed that all the SHPE were able to inhibit the activity of a-amylase and a-glucosidase and stimulated the insulin secretion in BRIN-BD11 cells. On the other hand, the anti-adipogenic properties of SHPE were in the reverse dose-dependent manner, where 100 µg SHPE/mL demonstrated a significant lower (p < 0.05) relative lipid accumulation (48.5 ± 0.03 per cent), intracellular triglyceride content (5.7 ± 0.07 mg/dL) and GPDH activity (1.0 ± 0.01 mU/mL). These findings reflected that 100 µg SHPE/mL was a potent anti-adipogenic agent when compared with other concentrations. In conclusion, soya husk could emerge as a potential hypoglycemic and anti-adipogenic agents in in vitro models.

This was the first study to explore the effectiveness of phytochemicals derived from soya bean husk in ameliorating hyperglycemia and adipogenesis. Promising findings that derived from the present study could enable the scientists to re-evaluate the potential use of agricultural wastes, especially in the formulation of nutraceuticals.

It would take billions of miles’ field road testing to demonstrate that the safety of automated vehicle is statistically significantly higher than the safety of human driving because that the accident of vehicle is rare event.

This paper proposes an accelerated testing method for automated vehicles safety evaluation based on improved importance sampling (IS) techniques. Taking the typical cut-in scenario as example, the proposed method extracts the critical variables of the scenario. Then, the distributions of critical variables are statistically fitted. The genetic algorithm is used to calculate the optimal IS parameters by solving an optimization problem. Considering the error of distribution fitting, the result is modified so that it can accurately reveal the safety benefits of automated vehicles in the real world.

Based on the naturalistic driving data in Shanghai, the proposed method is validated by simulation. The result shows that compared with the existing methods, the proposed method improves the test efficiency by 35 per cent, and the accuracy of accelerated test result is increased by 23 per cent.

This paper has three contributions. First, the genetic algorithm is used to calculate IS parameters, which improves the efficiency of test. Second, the result of test is modified by the error correction parameter, which improves the accuracy of test result. Third, typical high-risk cut-in scenarios in China are analyzed, and the proposed method is validated by simulation.

The purpose of this study is to investigate the effects of load and rotation speed on dry sliding of silicon nitride, including a series of tribological behaviors (friction coefficient, wear rate, temperature rise, etc.) and wear mechanism. Through the analysis of the above characteristics, the influence law of load and speed on them and the internal relationship between them are determined, and then the best comprehensive performance parameters of silicon nitride full-ceramic spherical plain bearings in dry sliding are predicted, which can provide guidance for the operation condition of silicon nitride full-ceramic spherical plain bearings in dry sliding.

The experimental study of different loads and rotation speeds under dry friction conditions was carried out by the using ball-disk sliding test method.

With the increase of load, the friction coefficient of silicon nitride friction pair and the wear rate of silicon nitride ball decrease continuously. With the increase of rotation speed, the friction coefficient of silicon nitride friction pair first increases and then decreases, and the wear of silicon nitride ball first increases and then decreases. With the increase of load and rotation speed, the wear mechanism eventually changes to adhesive wear.

Because of the low timeliness and inefficiency of bearing experiments, this work adopts a simple ball-disk model to comprehensively explore the influence rules of different conditions, which provides a theoretical basis for the subsequent practical application of silicon nitride full-ceramic spherical plain bearings.

Adopting an affective events perspective, our study investigates the relationship between perceived organizational politics (POP) and employee voice by exploring the mediating role of affect and the moderating role of supervisor political support.

The hypothesized model was tested with three-wave data collected from 393 full-time employees.

Results indicate that POP indirectly impacts employee voice through influencing positive and negative affect, and that supervisor political support moderates these indirect effects by moderating the relationship between POP and affective states.

Survey data can hardly test the causal relationship. Effect of employees' POP could be further examined in the lens subjective positive experiences. Organizational politics might have positive meanings.

Our findings show that POP brings employees negative feelings and reduces their voice behaviors while supervisor political support can mitigate this inhibiting effect. Therefore, managers should learn how to use political behavior more reasonably in highly political work environment.

By highlighting the possibility that employees can be beneficiaries having a vested interest in political environment and investigating the unexplored affective explanatory mechanisms underlying the POP–voice relationship, this study provides new directions for future research on POP and employee voice.

To cope with the workforce shortages brought by population ageing, it is critical to understand the workplace micro-foundations that determine the mechanisms of older workers' early retirement intentions. Drawing on the conservation of resource theory, this study examines the spillover effect of strain-based family-to-work conflict (SFWC) on early retirement intentions, with emotional exhaustion as a mediator. Additionally, it investigates the contextual resources, HR practice flexibility, as a boundary condition for the above relationships.

The study tests the hypotheses by employing a multi-sourced matching sample of 231 workers (aged 45–65) and their 49 managers.

The results of cross-level analysis revealed that SFWC has a positive indirect relationship with early retirement intentions, through increased emotional exhaustion. The relationship between emotional exhaustion and early retirement intentions is weaker when older employees experience higher HR practice flexibility.

This study is the first to use a resources perspective to analyse early retirement mechanisms, and it examines the spillover effect of SFWC on early retirement intentions. The findings also contribute to the literature on the role of HR practice for ageing workers.