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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/

Starting from corporate entrepreneurship, spin-off entrepreneurship and business model theory, this paper aims to examine the key influential factors and inherent mechanism in the process of business model transfer from parent enterprise to spin-off start-ups.

Grounded theory method is fit for constructing theoretical models, which can discover and interpret phenomenon and activities. According to the guidance of theoretical sampling and other core principles in grounded theory, this study extracts two parent enterprises named Haier and Phnix and lots of spin-offs derived from them.

This paper presents the theoretical framework that business models transfer from parents to spin-offs and probes into the embedding logic and connection relationship between factors and categories in this process, such as preconditions, incubation veins, business model elements, stripping mechanism and independent operations.

Although this study is focused on the manufacturing industry, the main characteristics, comparative advantages, governance rules summarized from transfer activities of business model in spin-off entrepreneurship can also bring inspirations to both parent enterprises and spin-off start-ups.

Excavates process and mechanism of business model transfer from internal to external, extends the theoretical perspectives about existing related theories such as corporate entrepreneurship, spin-off entrepreneurship and business model theory and reveals new approaches and methods on business model design, which is different from the past way.

Three strategic perspectives exist in dealing with globalization: convergence with the rational Anglo perspective, divergence of the local cultural perspective, and a hybrid cross‐vergence. A fourth alternative “transvergence” ‐ a transformative reinterpretation and application of the indigenous cultural perspective ‐ is identified, that firms can learn over time to combine their strong ties to the local environment with technological and institutional change. Three case studies highlight the process of transvergence. The findings suggest that a focus on the transvergence perspective can be an important addition to our understanding of how globalization can affect firm behavior and result in new business strategies.

The purpose of this paper is to reveal the transient thermo-elasto-hydrodynamic lubrication mechanism of a bidirectional thrust bearing in a pumped-storage unit, and to propose the transient simulation method of two-way fluid-solid-thermal interaction of thrust bearing.

The transient fluid-solid-thermal interaction method is used to simulate the three-dimensional lubrication of the thrust bearing, during the start-up and shutdown process of a pumped storage unit. A pad including an oil hole is modelled to analyze the temporal variation of lubrication characteristics, such as the film pressure, thickness and temperature, during the transient operation process.

The injection of the high-pressure oil sufficiently affects the lubrication characteristics on film, in which the hysteresis phenomena were found between the start-up and shutdown possess.

This paper reveals the transient lubrication mechanism of tilting pad in a thrust bearing, by means of transient fluid-solid-thermal interaction method. Lubrication characteristics are simulated without assuming the temperature relationship between the oil film inlet and the outlet and the heat transfer on the pad free surface. This paper provides a theoretical basis for the safe design and stable operation of thrust bearings.

This paper aims to manufacture Ti6Al4V/TiC functionally graded material (FGM) by direct laser deposition (DLD) using Ti6Al4V and TiC powder. The objective is to investigate the effect of process parameters and TiC composition on microstructure, Vickers hardness and mechanical properties.

Powder blends with three different volume percentages of Ti6Al4V and TiC were used as feed material for DLD process. Five experiments with different values of laser power and scan speed were conducted to investigate the effect on microstructure and Vickers hardness for different compositions of feed material. Mini-tensile tests were performed to evaluate the mechanical properties of the FGM samples. Digital image correlation (DIC) was applied to estimate Young’s modulus and ultimate tensile stress (UTS) of heterogeneous material.

This paper indicates that primary carbide, eutectic carbide and un-melted carbide phases are formed in the FGM deposit. As the energy density was increased, the primary and secondary dendrite arm spacing was found to increase. As TiC composition was increased, Young’s modulus increased and UTS decreased. The dendritic morphology of primary TiC growth was expected to cause low resistance for crack propagation, causing lower UTS values. Tensile specimens cut in vertical orientation were observed to possess higher values of Young’s modulus in comparison with specimens cut horizontally at low carbon content.

Current work presents unique and original contributions from the study of miniature FGM tensile specimens using DIC method. It investigates the effect of specimen orientation and TiC content on Young’s modulus and UTS. The relationship between energy density and dendritic arm spacing was evaluated. The relationship between laser power and scan speed with microstructure and Vickers hardness was investigated.

Suspension is a significantly important component for automotive and railway vehicles. Regenerative hydraulic-electric shock absorbers (RHSA) have been proposed for the purpose of attenuating vibration of vehicle suspension, and also recover kinetic energy originated from vehicle vibration that is conventionally dissipated by hydraulic dampers. To advance the technology, the paper aims to present an RHSA system for heavy-duty and railway vehicles and create a dynamic modelling to discuss on the development process of RHSA model.

First, the development of RHSA dynamic model can be resolved into three stage models (an ideal one, a second one with an added accumulator and a third one that considers both accumulator and system losses) to comprehensively evaluate the RHSA's characterisation. Second, a prototype is fabricated for testing and the results meet desired agreements between simulation and measurement. Finally, the study of key parameters is carried out to investigate the influences of hydraulic-cylinder size, hydraulic-motor displacement and accumulator pre-charged pressure on the RHSA system.

The findings of sensitivity analysis indicate that the component design can satisfy the damping characteristics and power performance required for heavy-duty vehicle, freight wagon and typical passenger train. The results also show that reducing the losses is highly beneficial for saving suspension energy, improving system reliability and increasing power-conversion efficiency.

The paper presents a more detailed method for the development and analysis of a RHSA. Compared with the typical shock absorbers, RHSA can also recover the vibration energy dissipated by suspension.

The purpose of this paper is to investigate the survival capability of Chaoshan people in the maritime world of the South China Sea amidst the changing monetary systems of the rival empires and political regimes from 1939 to 1945. It particularly focuses on overseas Chinese remittance business in Shantou under the Japanese rule. Local societies in coastal China and overseas Chinese communities in Southeast Asia experienced severe hardships due to the Sino-Japanese War, the Pacific War and the Chinese Civil War. As fighting among the rival empires and regimes intensified, Chinese migrant communities straddling between Southeast Asia and South China had to negotiate and adapt to survive these crises, regardless of whether they were government-affiliated or local autonomous subjects.

This research draws on archival materials to investigate the reactions of Chinese migrant communities in Chaoshan region in times of war and regime change. How did local maritime societies and overseas Chinese adapt to the harsh realities of the wartime? How did the Japanese Empire use Wang Jingwei’s puppet government in Nanjing to control the Chaoshan remittance network? How did the remittance network shift its operational structure in face of a wartime crisis?

Faced with the wartime crisis and the Japanese occupation, Chaoshan communities used a variety of survival strategies to protect and maintain the overseas Chinese remittance business. In dealing with remittances from Singapore, British Malay and Indonesia, they cooperated with the Japanese military authority and its puppet government to maximize the autonomy of their business operation in the Japanese-controlled East Asian Co-prosperity Sphere. On the other hand, to secure the flow of remittances from French Indochina and Thailand, the indirectly controlled territories in the Japanese Empire, Chaoshan merchants sought an alternative path of delivering remittances, known as the Dongxing route, to bypass the Japanese ban on private remittances from these two regions.

It would be a better research if more resources, including remittance receipts and documents during the Japanese occupation, could be found and used to show more detailed features of Chaoshan local society.

This research is the first one to investigate the contradictory features of local Chaoshan society during the Japanese occupation, an under-explored subject in the Chinese historiography.

JingWei BIAN is Director of Urban Construction Environment and Resources Committee of Xiamen Municipal People's Congress. He graduated from Tongji University with doctor's degree in urban planning and design. He is Professorate Senior Urban Planner and National Registered Urban Planner. He is a part-time Professor at Xiamen University, Huaqiao University and Jimei University. He has served as President of Xiamen Urban Planning and Design Institute and Deputy Director of Xiamen Planning Bureau. His main research interests are the urban planning theory and design, urban traffic planning, urban and rural planning management and regulations. He has published 4 books and over 50 papers on these topics.

This paper aims to develop a novel grey Bernoulli model with memory characteristics, which is designed to dynamically choose the optimal memory kernel function and the length of memory dependence period, ultimately enhancing the model's predictive accuracy.

This paper enhances the traditional grey Bernoulli model by introducing memory-dependent derivatives, resulting in a novel memory-dependent derivative grey model. Additionally, fractional-order accumulation is employed for preprocessing the original data. The length of the memory dependence period for memory-dependent derivatives is determined through grey correlation analysis. Furthermore, the whale optimization algorithm is utilized to optimize the cumulative order, power index and memory kernel function index of the model, enabling adaptability to diverse scenarios.

The selection of appropriate memory kernel functions and memory dependency lengths will improve model prediction performance. The model can adaptively select the memory kernel function and memory dependence length, and the performance of the model is better than other comparison models.

The model presented in this article has some limitations. The grey model is itself suitable for small sample data, and memory-dependent derivatives mainly consider the memory effect on a fixed length. Therefore, this model is mainly applicable to data prediction with short-term memory effect and has certain limitations on time series of long-term memory.

In practical systems, memory effects typically exhibit a decaying pattern, which is effectively characterized by the memory kernel function. The model in this study skillfully determines the appropriate kernel functions and memory dependency lengths to capture these memory effects, enhancing its alignment with real-world scenarios.

Based on the memory-dependent derivative method, a memory-dependent derivative grey Bernoulli model that more accurately reflects the actual memory effect is constructed and applied to power generation forecasting in China, South Korea and India.

The purpose of this study is to explore the relationship between environmental, social and governance (ESG) performance and tone management in the annual report. This is based on the notion that managers, driven by personal interests, may use their ESG accomplishments by using an abnormal positive tone to enhance their reputation or career prospects.

Using panel data from Chinese listed companies from 2010 to 2022, this study first investigates the relationship between ESG performance and abnormal tone management. The study then uncovers this relationship is mediated through the mechanisms of equity-based incentive and analyst coverage. The conclusions of this paper hold even after a series of robustness tests, such as propensity score matching, Heckman two-stage method and two-stage least squares with instrumental variables.

This study finds a positive correlation between ESG performance and the presence of abnormal positive tone in annual reports. Furthermore, the mechanistic analysis reveals that managers in companies with strong ESG performance are motivated to use an overly positive tone, largely due to their vested interests in equity-based compensation. Moreover, in an effort to alleviate the pressure stemming from heightened financial analyst coverage and enhance the impression conveyed through analysts' reports, managers with superior ESG performance also tend to inflate the tone within their annual reports.

This study provides significant insights into the ongoing dialogue surrounding ESG-related equity incentives, which incentivize managerial manipulation of stock prices through the use of abnormal positive tone. The findings call upon investors to exercise greater vigilance in examining narrative information in annual reports, as abnormally positive tones may not always faithfully represent performance but rather reflect managerial self-interest.

There is an emphasis on the importance of robust oversight mechanisms within corporate governance bodies to curb the manipulation of tone for managers’ personal gain.

This study enhances the theoretical foundation of ESG studies, offering a holistic perspective on the intricate interplay among ESG performance, managerial behavior and financial markets, with potential implications for researchers, investors and regulators.