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The purpose of this paper is to study the relationship between high temperature oxidation and temperature rise rate of engine oil attempted to explore a new indicator to evaluate oil degradation.

Accelerated oxidation test combined with molecular simulation and road test is carried out in this paper. The temperature rise characteristics of mineral oil and synthetic oil under different oxidation temperatures (140°C, 155°C and 170°C) and time (50 h, 100 h, 150 h and 200 h) were determined by accelerated oxidation. The mechanism of temperature change characteristics of used oils was analyzed with molecular simulation. Two experimental vehicles carried six road tests with synthetic and mineral oil.

The results of this study show that the temperature rise rate of oxidized mineral and synthetic oil is higher than the new oil. The temperature rise rate is proportional to the oxidation time and oxidation temperature. The synthetic engine oil temperature rise rate is lower than that of the mineral engine oil. The same result was obtained in road tests. Molecular simulation verifies that small molecules were generated after oil oxidation which results in intermolecular friction and increased heat generation.

This paper indicates that temperature rise rate has potential to be taken as an indicator to evaluate oil oxidation which provides a new way for engine oil analysis.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0177/

The purpose of this paper is to investigate the hydrodynamic performance of liquid film seals with oblique grooves (OGs) and spiral grooves (SGs), considering cavitation, compare and analyze the differences between them.

Considering cavitation effect, the incompressible steady-state Reynolds equation was solved to obtain the sealing performance parameters of the liquid film seal with oblique groove and spiral groove.

The hydrodynamic performance of oblique groove seal (OGS) and spiral groove seal (SGS) shows a similar trend with the change of operating parameters. When the groove angle is less than 20°, the load-carrying capacity of SGS is better than that of OGS, while when the groove angle continues to increase, the hydrodynamic performance of OGS is slightly better than that of SGS, and more suitable for use under small differential pressure and high speed.

The hydrodynamic characteristics of liquid film seals with oblique grooves and spiral grooves considering cavitation effect were studied, which provides a theoretical reference for the application of oblique groove seal.

This study aims to report the development and experimental evaluation of two kinds of PANI@semiconductor based photocathodic anti-corrosion coating, for application on stainless steel substrates.

PANI was in situ chemical polymerized on TiO₂ and BiVO₄ particles, and FT-IR and SEM/EDS were used to understand the characteristics and elemental distribution of the composite particles. Composite coatings, which consisted of epoxy, PANI@TiO₂ or PANI@BiVO₄ and graphene, were prepared on the 304L stainless steel. Photoelectrochemical response measurement, electrochemical tests and immersion tests were used to assess the anti-corrosion performance of the prepared coatings in 45°C 3.5 wt.% NaCl solution. And the corrosion protection mechanism was further explained by combining with surface observation.

The photoelectrochemical response tests revealed the good photocathodic effect of the coatings, and the reversible oxidation-reduction properties of PANI (pseudocapacitive effect) leading to the repeated usage of the coatings. Consequently, the anti-corrosion mechanism of the composite coating is attributed to the physical barrier effect of the coating, the anodic protection effect of PANI and the photocathodic and energy store effect.

These kind coatings could prevent corrosion from day to night for stainless steel, which has great engineering application prospects on stainless steel corrosion protection.

This study aims to investigate the effect of V doping on the microstructure, chemical stability, mechanical and vacuum tribological behavior of sputtered MoS₂ coatings.

The MoS₂-V coatings are fabricated via tuning V target current by magnetron sputtering technique. The structural characteristic and elemental content of the coatings are measured by field emission scanning electron microscopy, X-ray diffractometer, electron probe X-ray micro-analyzer, Raman, X-ray photoelectron spectroscopy, high resolution transmission electron microscope and energy dispersive spectrometer. The hardness of the deposited coatings are tested by a nanoindentation technique. The vacuum tribological properties of MoS₂-V coatings are studied by a ball-on-disc tribometer.

Introducing V into the MoS₂ coatings results in a more compact microstructure. The hardness of the coatings increases with the doping of V. The MoS₂-V coating deposited at a current of 0.2 A obtains the lowest friction coefficient (0.043) under vacuum. As the amount of V doping increases, the wear rate of the coating decreases first and then increases, among which the coating deposited at a current of 0.5 A has the lowest wear rate of 2.2 × 10–6 mm³/N·m.

This work elucidates the role of V doping on the lubrication mechanism of MoS₂ coatings in a vacuum environment, and the MoS₂-V coating is expected to be applied as a solid lubricant in space environment.

Drawing on identity theory and the symbolic interactionism perspective of identity theory, this study aims to construct a moderated mediation framework to test the effects of perceived overqualification (POQ) on knowledge sharing (KS) through professional identity threat (PIT) and the moderating role of coworkers' help-seeking behavior (CHSB).

This paper uses a quantitative multistudy research design with a combination of a scenario experiment (Study 1) and a two-wave field study among 220 supervisor-subordinate dyads at a power company in China. Using analysis of variance, confirmatory factor analysis (CFA) and bootstrapping method, the authors validated the research hypothesis.

In the scenario experiment study (study 1), the authors find that POQ is positively related to PIT and that CHSB negatively moderates the positive impact of POQ on PIT. The field study (study 2) replicated the above findings and found that PIT mediates the negative effect of POQ on KS. In addition, CHSB negatively moderates the mediating role of PIT between POQ and KS.

First, the current study extended the nomological network of POQ research by examining its influence on employees' KS. Second, this study empirically investigated the mediating role of PIT, which provided a new explanatory mechanism for the influence of POQ. Finally, this study demonstrates the moderating role of CHSB—a situational factor that has been ignored in previous studies.

Suggests that misunderstandings frequently occur when trying to understand Chinese language and culture, and so gives the implied meaning of various Chinese expressions and sayings such as greetings, thanks, respect, age, congratulations and taboo subjects.

This paper aims to examine the relationship between social presence and consumer purchase intention in the context of livestreaming commerce and test the mediating role of immersive experience and the moderating role of positive emotions.

The authors used a convenience sampling method to select 408 college students from a university in Ganzhou as the participants. They employed structural equation modeling to test the hypotheses, as well as Hayes' PROCESS to test the mediation and moderation effects.

The authors found that immersion experiences partially mediate the relationship between social presence and consumers' purchase intentions and positive emotions moderate the “social presence–immersion experience–consumer purchase intentions” path. Therefore, social presence constitutes a moderating mediating effect on consumer purchase intentions.

This study offers meaningful insights into how livestreamers and e-retailers can stimulate consumers' buying behavior in livestreaming environments. E-commerce platforms should strengthen consumer interactions and increase consumers' perceptions of social presence. In addition, companies should meet the social and psychological needs of consumers and generate positive emotional resonance.

This research sheds light on the effect of social presence on consumer purchase intentions in livestreaming commerce and extends the social presence literature by investigating the mediation mechanism of immersive experience.

This paper aims to introduce a high-temperature grease design method assisted by back propagation neural network (BPNN) and verify its application value.

First, the grease data sets were built by sorting out the base data of greases in a large number of literatures and textbooks. Second, the BPNN model was built, trained and tested. Then, the optimized BPNN model was used to search the unknown data space and find the composition of greases with excellent high-temperature performance. Finally, a grease was prepared according to the selected composition predicted by the model and the high-temperature physicochemical performance, high-temperature stability and tribological properties under different friction conditions were investigated.

Through high temperature tribology experiments, thermal gravimetric analysis and differential scanning calorimetry experiments, it is proved that the high temperature grease prepared based on BPNN has good high-temperature performance.

To the best of the authors’ knowledge, a new method of designing and exploring high-temperature greases is successfully proposed, which is useful and important for the industrial applications.

The historical development and size of China’s audit market provides an opportunity to investigate important questions regarding the functioning of the market for audit services that are difficult, if not impossible, to test in other globally established markets. The purpose of this paper is to examine the effect of the market entry of the Big Four accounting firms into China on the audit fees charged by its local accounting firms.

In this paper the authors rely primarily on the incumbent pricing literature (Simon, 2005; Geroski, 1995) to assist them in developing the specific hypotheses and empirical tests. This paper is an empirical study, which examines whether local incumbent accounting firms cut prices in response to the Big Four’s entry by using data from annual reports and audit reports for China’s listed companies from the 1994 to 2008 period.

This study shows that local incumbent firms cut prices post-entry. This study also finds that it was local large-sized accounting firms as well as accounting firms located in regions with highly developed- and competitive markets that cut prices in response to the Big Four’s entry.

This study has important implications for the Big Four accounting firms as it provides useful information about pricing strategies that would likely be used by local accounting firms in a new market. Local accounting firms in emerging markets can also gain useful insights about the pricing strategies adopted by the Big Four accounting firms when they enter a market.

Audit market research has little to offer on how local accounting firms respond in their pricing to the entry of Big Four accounting firms into their market, mainly because in western countries such as Canada, England, and the USA, the Big Four accounting firms are the oldest firms operating in those markets. This paper is the first study that examines the effect of the market entry of the Big Four accounting firms into China.

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses.

ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented.

Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties.

The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers.