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The purpose of this study is to investigate the sealing performance of different deep groove mechanical seals by considering the changing law of dynamic pressure effect and temperature gradient caused by high speed and high pressure.

A thermohydrodynamic lubrication model (THD) of the mechanical seal was constructed and solved using the commercial software FLUENT. The pressure and temperature distributions of the fluid under different groove types, as well as the sealing performance under different pressures, rotational speeds and sealing gaps, are obtained.

The annular groove (AG) can effectively reduce the temperature, and the T-type spiral groove (STG) can effectively inhibit the leakage. The increase of pressure and rotational speed leads to the enhancement of dynamic pressure effect and the increase of leakage, while the sealing gap increases and the leakage increases while taking away more heat. The choice of groove type is very important to the impact of sealing performance.

In consideration of the beneficial effect of deep grooves on cooling performance, the viscous temperature equation and the impact of the thermodynamic lubrication model are evaluated in conjunction with the sealing performance of four distinct groove types. This approach provides a theoretical basis for the optimal design of mechanical seals.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0184/

This study aims to research the erosion wear characteristics and sealing performance of V-regulating ball valve in coal chemical process pipelines, which provides a theoretical reference for improving its antiwear and sealing performance.

Taking the V-regulating ball valve as the research object, based on the computational fluid dynamics and the theory of erosion wear, the authors studied its erosion characteristics under different medium parameters and analyzed the sealing performance under the heat-fluid–solid coupling working condition.

The erosion wear mechanism of the valve sealing surface is the simultaneous action of cutting and deformation. When the medium flow velocity, particle mass flow rate and particle size increase, the maximum erosion rate and average erosion rate in the V-regulating valve increase. The inner diameter Mises contact stress of the sealing surface is symmetrically distributed in a “wing shape,” and the contact stress of the outer diameter is distributed in a “butterfly shape.” Due to the superposition of thermal stress and pressure stress in the contact transition zone to produce a significant stress concentration.

The findings will provide a theoretical basis for improving the erosion resistance and sealing performance of V-regulating ball valve in coal chemical industry.

V-type regulating ball valve is widely favored by coal chemical enterprises and petrochemical enterprises because of its wide adjustment ratio and good erosion resistance.

The V-regulating ball valve wear mechanism for cutting and deformation simultaneously, and its wear rate is positively correlated with the medium flow rate, particle mass flow rate and particle size. After the valve is opened, there is a significant stress concentration occurs in the contact transition zone due to the superposition of thermal stress and compressive stress. The findings will provide a theoretical basis for improving the erosion resistance and sealing performance of V-regulating ball valve in coal chemical industry.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0205/

How to use a simple and classical topology to provide a high-efficiency excitation voltage for dielectric barrier discharge (DBD) loads is one of the primary problems to be solved for DBD application fields.

To address the issue, a set of modes that can generate a high-efficiency pulse excitation voltage in a full-bridge inverter are adopted. With the set of modes, the unique equivalent circuit of DBD loads and the parasitic parameter of the step-up transformer can be fully used. Based on the set of modes, a control strategy for the full-bridge inverter is designed. To test the performance of the power supply, a simulation model is established and an experimental prototype is made with a DBD excimer lamp.

The simulation and experimental results show that not only a high-efficiency excitation voltage can be generated for the DBD load, but also the soft switching of all power switch is realized. Besides this, with the set of modes and the proposed control strategy, the inverter can operate in a high frequency. Compared with other types of power supplies, the power supply used in the paper can fully take advantage of the potential of the excimer lamp at the same input power.

This work considers that how to use a simple and classical topology to provide a high-efficiency excitation voltage for DBD loads is one of the primary problems to be solved for DBD application fields.

This paper aims to explore why some Chinese subordinates will engage in building guanxi with their supervisor while others will not. The authors conceptualize subordinates’ initiative behaviors which aim at building up or improving guanxi with their supervisors through social interactions as supervisor–subordinate guanxi (SSG)-building behaviors. Guided by the theory of planned behavior (TPB), this study examines how three psychological antecedents (guanxi orientation as attitude, individual perception of group-level guanxi practice as subjective norm and person–supervisor [P-S] fit perception as perceived control) independently and interactively predict subordinates’ SSG-building behaviors.

The authors used a sample of 162 supervisor–subordinate dyads from four enterprises located in Southwest China.

Results indicated that P-S fit perception is most strongly related to subordinates’ SSG-building behaviors, followed by guanxi orientation and individual perception of group-level guanxi practice perception. Guanxi orientation is also found to strengthen the positive effect of P-S fit perception on subordinates’ SSG-building behaviors.

The authors’ findings shed light on the psychological mechanisms of Chinese subordinates’ behaviors to build up or improve guanxi with their supervisors, and advance the current understanding of SSG development from a planned behavioral perspective.

The purpose of this study is to explore the impact of work-to-family conflict (WFC) on unethical pro-family behavior (UPFB) and work engagement (WE) among Chinese female leaders. In addition, this study investigates the mediating role of work-to-family guilt (WFG) and the moderating role of family centrality (FC) in these relationships.

A quantitative approach was adopted, involving the collection of data through online questionnaires administered at three time points. These data were analyzed using hierarchical regression and the bootstrapping method to test the proposed hypotheses.

WFC exhibited a significant positive correlation with UPFB and a negative correlation with WE; WFG played a mediating role in the relationships between WFC and both UPFB and WE; and FC had a significant moderating effect on the relationship between WFC and WE.

This study sheds light on a model of WFC and its related effects, reveals how WFC affects UPFB and WE and uncovers the mediating role of WFG and the moderating role of FC; pays attention to a unique organizational behavior, UPFB, which enriches research on the antecedents influencing such behaviors; and examines Chinese female leaders in organizations, their current experience of WFC and the resulting psychological and behavioral outcomes.

The purpose of this study is to examine the effects of executives’ overseas education and work experience on enterprise digital as executives’ overseas background is critical to the development of enterprises. It also explored the mediating role of enterprise digital transformation on the relationship between executives’ overseas background and enterprise growth.

Chinese A-share companies listed on the Shanghai and Shenzhen Stock Exchanges for the period 2018–2020 were analyzed using regression analysis and bootstrapping to verify hypothesized relationships.

Executives’ overseas study and work experience both enhanced enterprise digital transformation significantly, thus improving enterprise growth. The level of employee education moderated the mediating role proposed in the theoretical model. Moreover, the promoting effect of executives’ overseas background on enterprise digital transformation was more significant for non-state-owned enterprises and those in eastern China.

The findings provide reference for the formulation and optimization of companies’ human resource structure and have implications on the improvement of enterprise digital transformation and enterprise growth.

This study explored the factors influencing enterprise digital transformation at the microlevel of corporate human capital, thereby providing microlevel empirical evidence for research on the factors influencing enterprise digital transformation. Its findings shed light on the mechanism and context under which executives with overseas backgrounds may enhance enterprise digital transformation and growth.

Small talk, often regarded as a superficial interaction unrelated to work, is a pervasive and inescapable aspect of daily life and professional settings. In China, where the notion of guanxi – the cultivation of strategic relationships – is deeply valued, workplace small talk (WST) is a strategic tool used by employees to strengthen their interpersonal networks. This study aims to investigate the positive impact of WST on task performance within the Chinese workplace and explores the mechanisms underpinning this relationship.

This study adopted a time-lagged research design to test its hypotheses using data from 516 employees across various Chinese firms.

This study revealed that WST exerts both direct and indirect positive effects on task performance. It boosts task performance indirectly via two mediators: relational energy and positive affect. This study also delineated a chain mediation model wherein WST sequentially elevates task performance by first enhancing relational energy and then fostering positive affect.

Counter to the prevailing focus on the negative repercussions of WST, this study sheds light on its beneficial outcomes, proposing novel pathways connecting WST to task performance. These insights contribute to both academic discourse and the development of practical management strategies.

The content of pore-foaming agent directly affects pore characteristics and oil-absorption properties of polyimide (PI) porous materials, which further influence the tribological performance of PI pore material. This research paper aims to discuss these issues.

Thermal vacuum molding technology was adopted to prepare PI porous material with different structures by changing the content of the pore-forming agent to control pore size and porosity of the PI material. PI oil-bearing materials were obtained by vacuum oil immersion. The tribological experiments of PI oil-bearing materials were conducted on the CETR friction and wear testing machine.

The study results showed that PI porous material with a specific structure can be obtained by controlling the content of a pore-forming agent. In a certain range, with the increase in the content of the pore-forming agent, the average pore size and porosity increased, also the oil content increased, which means that the friction coefficient and wear rate decreased to a very large extent, and antifriction and wear resistant properties of the PI porous materials greatly improved. When the content of the pore-forming agent exceeds 8 per cent, the wear rate and friction coefficient of the PI porous materials began to increase.

Because the complexity of the tribological system consists of lubricating oil, porous material and friction pair, the physical understanding of the mechanism of this process remains limited. Therefore, the present research was undertaken to identify the phenomena involved, which will provide practical guidance for the tribological application in the field of bearing parts.

While many studies have focused on the effectiveness of service recovery after encountering service failure, few have considered for pre-recovery opportunities. Drawing on service guarantee research and the inoculation theory, this study examines the effect of pre-recovery strategy on customer’s satisfaction when faced with possible service failure. This study takes into consideration the uncertainty of service failure, including specific or unpredicted failures.

Three experimental studies were conducted to examine our research hypotheses, which include a total of 1203 subjects recruited from online and offline platforms.

The findings reveal that service guarantees and inoculation messages both effectively mitigate the negative consequences of a service failure. Specifically, the pre-recovery strategy is particularly effective for specific service failures. In addition, we thoroughly examined the mediating role of customer attribution.

This research significantly contributes to the existing literature on service research by delving into the potential positive impact of proactive measures undertaken by service enterprises. Furthermore, the findings of this research offer valuable insights for practitioners.

The occurrence and dissemination of hate videos in social media platform could pose serious harm to both society and individuals. However, the characteristics of the hate videos increase the difficulty of detection task. Hate content is usually presented in a relatively covert manner in videos, and textual content in videos plays an important role in hate video detection. In this work, we propose a textual context enhanced dynamic bimodal fusion (TCE-DBF) method for hate video detection.

The proposed method TCE-DBF introduces dynamic modality gate (DMG) and bimodal fusion transformer network to dynamically integrate multimodalities. Moreover, in order to enhance textual modality in videos, two types of textual context from the video are taken as the input of TCE-DBF. One is extracted from video frames in visual modality. The other is extracted from audio in acoustic modality. Specially, TCE-DBF splits the original audio and learns the sequence representation to capture acoustic temporal information.

Hate video detection has been one of the hotspots in recent works. However, it still faces two serious challenges. The first challenge is the hate content in videos presented in multimodalities. The second challenge is how to evaluate the importance of different modalities for multimodal fusion modeling. TCE-DBF aims to tackle these challenges. Experimental results on hate video dataset HateMM demonstrate that TCE-DBF outperforms the state-of-the-art methods, and the visualization results show that textual modality plays a more important role in hate video detection. Therefore, it is vital to consider the text in videos.

TCE-DBF can be utilized to effectively detect hate videos on social media. Besides transcript, TCE-DBF considers text in video frames, which makes detection more accurate. Meanwhile, to better achieve multimodal fusion, TCE-DBF uses DMG and bimodal fusion transformer network to dynamically assign different weights to three modalities and integrate them. The proposed TCE-DBF is novel in terms of capturing multimodal features, enhancing the textual modality and achieving high detection performance for hate video detection.