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The purpose of this study is to systematically investigate the novel phenomenon of rail corrugation on small radius curves with rail joints in mountainous city metros, characterized by the coexistence of short and long wavelengths (30–40 mm and 150–200 mm) on the low rail.

The finite element model of the wheel-rail system in the section with rail joint is constructed based on field surveys. The friction-coupled vibration characteristics of the wheel-rail system are studied from the perspective of friction self-excited vibration of the wheel-rail system and feedback vibration of the rail irregularity.

The rail corrugation with short wavelength is primarily induced by the friction self-excited vibration of wheel-rail system. In contrast, the rail corrugation with long wavelength is predominantly caused by the feedback vibration of rail joint irregularity. Additionally, the feedback vibration of corrugated irregularity accelerates the progression of corrugation depth without triggering the emergence of rail corrugation with new wavelength.

The research advances the understanding of the vibration inducement behind rail corrugation in mountainous city metros.

Axleboxes are an important structure that connects the wheelset with the bogie frame. Inside axlebox bogies have lower wheelset yaw angle stiffness and better curve-passing performance. The purpose of this paper to study the differences in the wear evolution law and the influencing factors of the two types of metro vehicles.

This paper established the dynamic model and wear model of both outside axlebox and inside axlebox metro vehicles to research the wheel wear evolution law of the two types of vehicles. The curve passing performance of two vehicles is analyzed. The effect of key parameters on wheel wear is studied, including the lateral distance of the axlebox, the longitudinal stiffness of the rotary arm node, the lateral stiffness of the rotary arm node and the wheel profiles.

The results showed that the model of inside axlebox metro vehicles improved vehicle safety and curve-passing performance. At the same time, inside axlebox metro vehicles reduce wheel wear of the wheel tread area and wheel flange area. When the S1002 wheel tread profile matched with the vehicle parameters, the wheel wear is minimized.

This paper established a dynamic model for inside axleboxes metro vehicles, then used a wheel wear model to analyze the evolution of wheel wear and the key influencing factors of the inside axleboxes metro vehicles.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0256/

With the increased speed and mileage of high-speed lines, the problem of rail wear is increasing. In actual operation, a large number of abnormal wear phenomena occur on both vehicles and rails during fixed line operation; therefore, the purpose of the study is to explored the rail wear for a variety of vehicles running in mixed operation.

This paper used the universal mechanism multibody dynamics software to establish the CRH2 high speed train (HST) and the CRH3 HST vehicle dynamic models, respectively. The mixed running of HSTs on the effect of rail wear evolution law was analyzed. The rail wear of the two vehicles with different curve radii, different wheel diameters and different under-rail stiffness was compared and analyzed.

The result showed that the rail wear of CRH3 HST is greater than that of CRH2 HST. The rail wear in the tangent track under mixed operation conditions is 25.4% less than when CRH3 HST operated independently. When there is a 1-mm wheel diameter difference, the maximum rail wear of CRH2 HST and CRH3 HST increases by 263% and 44%, respectively. The amount of rail wear is proportional to the under-rail stiffness, and the position of the maximum wear is almost unchanged.

Most studies on the evolution law of rail wear are conducted for a single vehicle type and a single line. This study explored the mixed running of HSTs on the effect of rail wear evolution law.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0276/

The purpose of this paper is to improve the generation efficiency of singlet oxygen of methylene blue molecules through finely controlling their aggregation states in drug carriers.

As a photosensitiser in photodynamic therapy, methylene blue (MB) was loaded on citrate-modified hydroxyapatite (HAp) through an electrostatic interaction and followed by encapsulation of coordination complexes of tannic acid (TA) and Fe(III) ions. Ultraviolet-visible absorption spectrum of the supernatant after incubation of samples was recorded at certain time interval to investigate the release behaviour of MB. Photodynamic activity of MB was determined by the oxidation reaction of uric acid by singlet oxygen generated by MB under illumination.

Almost all MB molecules were immediately released from HAp-MB, whilst an initial burst release of MB from HAp-MB@TA was followed by a sustainable and pH-sensitised release. In comparison with HAp-MB, photocatalystic reduction of HAp-MB@TA by titanium dioxide hardly occurred under illumination, indicating the stability against reduction to leukomethylene blue in vitro. Generation efficiency of singlet oxygen by MB released from HAp-MB@TA was significantly higher than that from HAp-MB because of the control of TA and Fe(III) ions complexes on molecular structures of released MB.

A facile method was herein demonstrated to optimise the generation efficiency of singlet oxygen by controlling aggregation states of PS molecules and improve PDT efficiency to damage tumour tissues.

High-strength martensitic steels having strong hydrogen embrittlement (HE) susceptibility and the metal carbide (MC) nanoprecipitates of microalloying elements such as Nb, V, Ti and Mo in the steel matrix can effectively improve the HE resistance of steels. This paper aims to review the effect of MC nanoprecipitates on the HE resistance of high-strength martensitic steels.

In this paper, the effects of MC nanoprecipitates on the HE resistance of high-strength martensitic steels are systematically described in terms of the types of MC nanoprecipitates, the influencing factors, along with numerical simulations.

The MC nanoprecipitates, which are fine and semicoherent with the matrix, effectively improve the HE resistance of steel through the hydrogen trapping effects and microstructure optimization, but its effect on the HE resistance of steel is controlled by its size, number and distribution state.

This paper summarizes the effects and mechanisms of MC nanoprecipitates on HE performance of high-strength martensitic steel and provides the theoretical basis for corrosion engineers to design high-strength martensitic steels with excellent HE resistance and improve production processes.

This paper aims to explore the impact of business environment on high-quality economic development (HQED) and clarify the role of technological innovation and government intervention in this relationship.

Based on China’s provincial panel data from 2010 to 2019, this paper adopts the system generalized method of moments to empirically analyze the influential mechanism and heterogeneity of the business environment on HQED. Furthermore, the authors construct a dynamic panel threshold model to test the threshold effect of government intervention.

The results indicate that optimizing the business environment can significantly promote HQED, technological innovation plays a partial mediating role in the impact of business environment on HQED, mainly by enhancing the intensity of innovation input and increasing innovation output to facilitate HQED. Government intervention can regulate the impact of business environment on HQED, and there is a double threshold effect, and it possesses an inverted U-shaped feature of first promoting and then inhibiting.

This paper examines the influence path of business environment on HQED from the perspective of technological innovation and government intervention, filling the gap in the study of provincial business environment. Moreover, the conclusions furnish a theoretical basis for optimizing the business environment and facilitating the HQED in China.

In recent decades, emerging market multinational enterprises (EMNEs) have predominantly adopted a big step internationalization strategy to expand their business overseas. This study aims to examine the effect of big step internationalization on the speed of subsequent foreign direct investment (FDI) expansion for EMNEs. The authors also investigate the potential boundary conditions.

The authors use the random effects generalized least squares (GLS) regression following a hierarchical approach to analyze the panel data set conducted by a sample of publicly listed Chinese firms from 2001 to 2012.

The findings indicate that implementing big step internationalization in the initial stages accelerates the speed of subsequent FDI expansion. Notably, the authors find that this effect is more pronounced for firms that opt for acquisitions as the entry mode in their first big step internationalization and possess a board of directors with strong political connections to their home country’s government. In contrast, the board of director’s international experience negatively moderates this effect.

This study provides insights into our scholarly and practical understanding of EMNEs’ big step internationalization and subsequent FDI expansion speed, which offers important implications for firms’ decision-makers and policymakers.

This study extends the internationalization theory, broadens the international business literature on the consequences of big step internationalization and deepens the theoretical and practical understanding of foreign expansion strategies in EMNEs.

The purpose of this paper is to examine the relationship between Chinese female executives and corporate risk-taking the contingencies that affect this relationship.

A integrated theoretical framework was established, on the basis of which theoretical hypotheses were developed and tested using 20,315 firm-year observations collected from China’s publicly listed companies during the period 2005–2020. Data were collected from China's Shanghai and Shenzhen A-share Stock Exchanges and analyzed using a moderated regression analysis, PSM, 2SLS-IV and PSM-DID model.

The empirical results indicate a negative effect of the ratio of female executives in top management team on corporate risk-taking, and this negative effect can be weakened by the social capital of board directors and the regional marketization.

The paper contributes to research on the relationship between female executives and risk-taking by considering the effect of eastern culture on female executives’ business decision-making and examining the moderating factors inside and outside the firm.

The paper illustrates the active steps that corporations can take to enhance female executives' willingness and capacity to take firm-related risks so as to improve the firm value in the long run.

The paper explores how Chinese culture and Chinese traditional value affect female executives’ decision-making on risky projects or uncertain investments. In addition, our study for the first time examines the moderating effect of board social capital as an internal factor and marketization as an external one on the relationship between Chinese female executives and corporate risk taking. The research examines the gender inequality in the work and competitive environment facing female executives in the areas of different marketization level, which would affect female executives’ cognition and motivation in corporate risk taking.

Real‐time multimedia supervisory systems generally include a distributed system that delivers live video input captured with cameras at the watched person's site, using a PC or hand‐held device at the distant supervisor's site. The system comprises many entities such as cameras for image capture, transmission software, network connections, receiver software, a display device, multimedia processing software and hardware, control software, etc. The purpose of this paper is to realize a safe and convenient supervisory system that autonomously provides users with services that fulfill users' requirements related to quality and privacy in a ubiquitous information environment.

A system is designed by integrating environmental information acquired from the real world and knowledge related to human social activities. A real space understanding mechanism is proposed to infer the situations and relationships of users by combining sensing information and social knowledge. Social knowledge related to human relationships, the life style of the watched person, home structure, etc. is used with ontology to infer the situations of users.

An early prototype was implemented for supervising elderly people and some experiments were performed based on several scenarios. Results obtained from some experiments confirmed that this supervisory system can provide real‐time multimedia supervisory services for elderly people, with reasonable quality‐of‐service and privacy that meet the users' requirements.

The system described in this paper assesses the situation of users and surrounding environmental information to provide appropriate supervisory services. This paper provides insight into the design and development of ubiquitous application systems to realize comfortable and safe services using a combination of environmental information and social knowledge.

This viewpoint paper aims to discuss sustainable digitalisation of facilities management (FM) through the implementation of the newly recognised International Organization for Standardization (ISO) standards within the ISO 41000 series.

This viewpoint paper provides a review of the literature of the recent ISO documents and academic study. The content is also dependent on the authors’ opinions and interpretation.

FM is currently shifting emphasis towards a strategic focus through the adoption of the new recognised international ISO standards that consider sustainable digitalisation in business decisions. However, the FM sector is encountering potential risks to the implementation of the new recognised international ISO standards. Digitalisation is one kind of force that has shaped the management of the built environment and FM recently and rapidly, especially in the Covid-19 period. This is impacting the FM industry. As standardisation aims at establishing a constantly evolving baseline of proven practices, standardisation can be considered a part of sustainable FM. It is believed that standardised and strategic level support is crucial for the smooth adoption of sustainable FM practices and processes. Standards such as the ISO standards, applied to the global FM industry, help in objectively quantifying the added value of FM to the core business. Advanced technology and digitalisation can contribute to the sustainability of any profession and industry, but it also requires a community to tackle the problems.

This paper contributes to the FM industry by making recommendations for improvement in the use of digitalisation. In summary, the significant finding of this viewpoint paper is that digitalisation offers both possibilities and problems in the application of the new recognised international ISO standards within the FM industry.