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Article
Publication date: 5 February 2025

Xiaohong Gao, Yizheng Wang, Tianlong Wang, Feibo Li, Yanming Wang and Xiaoliang Zhang

The anti-friction and anti-wear properties of WS2@GO composites on paraffin liquid were investigated with a four-ball tribometer.

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Abstract

Purpose

The anti-friction and anti-wear properties of WS2@GO composites on paraffin liquid were investigated with a four-ball tribometer.

Design/methodology/approach

A series of graphene oxide (GO) nano hybrid composites decorated with tungsten disulfide (WS2) were prepared in-suit by hydrothermal strategy.

Findings

The results showed that compared to the virgin oil, friction coefficient and diameter of wear scare of lubricant oil containing W/G = 1:1 hybrid composite was reduced by 42.7% and 31.6%, respectively. At the microscopic, the excellent lubrication performance resulted from the tribo-chemical reaction on the sliding interface, which promotes the formation of tribo-film with a thickness of 8 nm. The carbonization compound, WO3 and Fe2O3 in the tribo-film results from the tribo-chemical reactions at the sliding interface, which can improve the stability and strength of tribo-film. Thereby the metal surface was further protected from friction and wear.

Originality/value

A series of WS2@GO composites were prepared in-suit by a hydrothermal strategy, and the tribo-film was analyzed by the transmission electron microscope and X-ray photoelectron spectrometer.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2024-0397

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 7 August 2023

Jiayuan Yan, Xiaoliang Zhang and Yanming Wang

As a high-performance engineering plastic, polyimide (PI) is widely used in the aerospace, electronics and automotive industries. This paper aims to review the latest progress in…

306

Abstract

Purpose

As a high-performance engineering plastic, polyimide (PI) is widely used in the aerospace, electronics and automotive industries. This paper aims to review the latest progress in the tribological properties of PI-based composites, especially the effects of nanofiller selection, composite structure design and material modification on the tribological and mechanical properties of PI-matrix composites.

Design/methodology/approach

The preparation technology of PI and its composites is introduced and the effects of carbon nanotubes (CNTs), carbon fibers (CFs), graphene and its derivatives on the mechanical and tribological properties of PI-based composites are discussed. The effects of different nanofillers on tensile strength, tensile modulus, coefficient of friction and wear rate of PI-based composites are compared.

Findings

CNTs can serve as the strengthening and lubricating phase of PI, whereas CFs can significantly enhance the mechanical properties of the matrix. Two-dimensional graphene and its derivatives have a high modulus of elasticity and self-lubricating properties, making them ideal nanofillers to improve the lubrication performance of PI. In addition, copolymerization can improve the fracture toughness and impact resistance of PI, thereby enhancing its mechanical properties.

Originality/value

The mechanical and tribological properties of PI matrix composites vary depending on the nanofiller. Compared with nanofibers and nanoparticles, layered reinforcements can better improve the friction properties of PI composites. The synergistic effect of different composite fillers will become an important research system in the field of tribology in the future.

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 August 2018

Minna Yu and Yanming Wang

The purpose of this paper is to examine the impact of corporate governance on the capital market participants’ abilities to forecast future performance, as measured by the…

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Abstract

Purpose

The purpose of this paper is to examine the impact of corporate governance on the capital market participants’ abilities to forecast future performance, as measured by the properties of analysts’ earnings forecasts in Asian stock markets.

Design/methodology/approach

This paper hypothesizes that higher corporate governance is associated with lower forecast errors, lower forecast dispersion and lower forecast revision volatility.

Findings

These predictions are supported with a sample of companies across eleven Asian economies over 2004-2012. The results of this paper suggest that corporate governance plays a significant role in the predictability of firm’s future performance and, therefore, improves the financial environment in Asian stock markets. Furthermore, the impact of corporate governance on analysts’ forecast properties is more pronounced in countries with strong investor protection.

Research/limitations/implications

The authors acknowledge the following limitations of this paper. First, the results of this paper may be subject to omitted-variable bias and endogeneity issue. The authors have used control variables in the regressions to reduce the omitted variable bias. The authors have run lead-lag regressions to address causality issue. Second, CLSA corporate governance scores are collected for largest companies in each jurisdiction. Therefore, the sample is biased towards the largest companies in those jurisdictions and may not be representative of the average firm in the Asia.

Originality/value

The results of this paper speak to the benefit of having strong corporate governance in terms of reducing the information asymmetry between investors and corporate management.

Details

International Journal of Accounting & Information Management, vol. 26 no. 3
Type: Research Article
ISSN: 1834-7649

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Article
Publication date: 9 November 2012

George K. Stylios

Examines the seventeenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…

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Abstract

Examines the seventeenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 24 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 15 November 2011

George K. Stylios

Examines the sixteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…

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Abstract

Examines the sixteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 23 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 20 February 2019

Jing Qi, Catherine Manathunga, Michael Singh and Tracey Bunda

The purpose of this paper is to provide a micro historical account of the work of a key Chinese educational reformer, Tao Xingzhi (1891–1946), who transformed educational ideas…

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Abstract

Purpose

The purpose of this paper is to provide a micro historical account of the work of a key Chinese educational reformer, Tao Xingzhi (1891–1946), who transformed educational ideas from John Dewey to effect social and cultural change in 1920s–1940s China.

Design/methodology/approach

This paper examines English and Chinese language sources, including Tao’s poetry, to present a fresh analysis of Tao’s epistemological life history. It draws upon transnational historical approaches to chart the multidirectional circulation of progressive education philosophies around the globe. It also explores some conceptual dimensions of Chinese historical thinking and historiographical strategies.

Findings

Tao Xingzhi engaged in critical intercultural knowledge exchange in implementing educational reforms in China. He blended and critiqued Chinese and Deweyian educational philosophies to create unique educational reform, which involved reversing some of Dewey’s approaches as well as adapting others.

Originality/value

This paper foregrounds Tao Xingzhi’s agency in transforming some of Dewey’s ideas in the Chinese context and challenges studies that adopt an “impact-response” approach to Tao’s contribution, which suggest a one-way flow of knowledge from a “modern” West to a “traditional” China. It brings hitherto unexplored Chinese language sources to an English-speaking audience, particularly Tao’s poetry, to gain new historical insights into Tao’s educational reforms. It contributes to transnational understandings of the multidirectional flows of knowledge about Progressive educational philosophies around the world.

Details

History of Education Review, vol. 48 no. 1
Type: Research Article
ISSN: 0819-8691

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Article
Publication date: 16 January 2025

Yanming Zhao, Jinhao Wu, Yongbo Zhu and Li’an Gu

This paper aims to reduce the impact of noise on the prediction accuracy of remaining useful life (RUL) for supercapacitor. First, Savitzky–Golay (SG) smoothing filter method …

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Abstract

Purpose

This paper aims to reduce the impact of noise on the prediction accuracy of remaining useful life (RUL) for supercapacitor. First, Savitzky–Golay (SG) smoothing filter method (Savitzky and Golay, 1964) is used to eliminate the local small fluctuation and high-frequency noises that are generated by the capacity drop and rebound during the charging and discharging process of supercapacitor. Then, the variational mode decomposition (VMD) method is used to eliminate large fluctuation noises that are caused by internal temperature change of supercapacitor and chemical reaction of the supercapacitor. Its parameters are optimized by using marine predators algorithm (MPA), and the capacity sequence after denoising is reconstructed. Finally, long short term memory neural networks (LSTM) is used to predict the performance degradation law (PDL) and remaining useful life (RUL) of supercapacitor for the reconstructed sequence, then the comparative analysis is conducted with other methods, which results show this method improves the prediction accuracy effectively, and provides theoretical support for timely and accurately understanding the PDL and RUL of supercapacitor backup power supply.

Design/methodology/approach

First, SG smoothing filter method is used to eliminate the local small fluctuation and high-frequency noises that are generated by the capacity drop and rebound during the charging and discharging process of supercapacitor. Then, the VMD method is used to eliminate large fluctuation noises that are caused by internal temperature change of supercapacitor and chemical reaction of the supercapacitor. Its parameters are optimized by using MPA, and the capacity sequence after denoising is reconstructed. Finally, LSTM is used to predict the PDL and RUL of supercapacitor for the reconstructed sequence, then the comparative analysis is conducted with other methods, the results show that this method improves the prediction accuracy effectively, and provides theoretical support for timely and accurate understanding the PDL and RUL of supercapacitor backup power supply.

Findings

These factors will bring different types of noise during the service process of supercapacitor backup power supply, such as capacity regeneration, differences of charging and discharging rate, internal temperature change of supercapacitor, chemical reaction and external electromagnetic interference. Therefore, the paper proposes an LSTM prediction method of supercapacitor’s PDL and RUL based on composite denoising, which is divided into three stages: smoothing, noise reduction and prediction. First, SG smoothing filter method is used to eliminate the local small fluctuation and high-frequency noises, and MPA-VMD method is used to eliminate the nonlinear and nonstationary noises. Then, the capacity sequence after denoising is reconstructed, LSTM is used to predict PDL and RUL of supercapacitor. Finally, the comparative analysis with other methods is carried out. The results show that SG-VMD-LSTM method has higher prediction accuracy, which can accurately predict PDL and RUL of supercapacitor backup power supply, and improve the safety and reliability of wind turbine operation under the severe wind conditions.

Originality/value

The comparative analysis with other methods is carried out. The results show that SG-VMD-LSTM method has higher prediction accuracy, which can accurately predict PDL and RUL of supercapacitor backup power supply, and improve the safety and reliability of wind turbine operation under the severe wind conditions.

Details

Circuit World, vol. 51 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 21 April 2022

Zuanbo Zhou, Wenxin Yu, Junnian Wang, Yanming Zhao and Meiting Liu

With the development of integrated circuit and communication technology, digital secure communication has become a research hotspot. This paper aims to design a five-dimensional…

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Abstract

Purpose

With the development of integrated circuit and communication technology, digital secure communication has become a research hotspot. This paper aims to design a five-dimensional fractional-order chaotic secure communication circuit with sliding mode synchronous based on microcontroller (MCU).

Design/methodology/approach

First, a five-dimensional fractional-order chaotic system for encryption is constructed. The approximate numerical solution of fractional-order chaotic system is calculated by Adomian decomposition method, and the phase diagram is obtained. Then, combined with the complexity and 0–1 test algorithm, the parameters of fractional-order chaotic system for encryption are selected. In addition, a sliding mode controller based on the new reaching law is constructed, and its stability is proved. The chaotic system can be synchronized in a short time by using sliding mode control synchronization.

Findings

The electronic circuit is implemented to verify the feasibility and effectiveness of the designed scheme.

Originality/value

It is feasible to realize fractional-order chaotic secure communication using MCU, and further reducing the synchronization error is the focus of future work.

Details

Circuit World, vol. 49 no. 4
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 21 January 2022

Shuai Han, Tongtong Sun, Yanming Sun and Xi Gao

The COVID-19 outbreak has been effectively controlled in China, but the resulting public psychological crisis is a latent, persistent and torturous disaster. This crisis affects…

155

Abstract

Purpose

The COVID-19 outbreak has been effectively controlled in China, but the resulting public psychological crisis is a latent, persistent and torturous disaster. This crisis affects not only the individual’s health but also social stability. This study aims to reveal the structure and situation of public psychological crisis during the remission period of the COVID-19 epidemic.

Design/methodology/approach

A questionnaire survey of the psychological crisis was conducted from February to May 2021. Data was collected from 1,056 respondents from different provinces in China.

Findings

The findings reveal the dangerous risks of public psychological crises. The specific results are as follows: first, a hierarchical state structure of psychological crisis is constructed and characterized as a significant gradient decline, namely, anxious state>panic state>depressive state>hostile state. Second, 43.939% of respondents reported an anxious state, 46.780% reported a panic state, 40.909% reported a depressive state, 28.883% reported a hostile state and 22.254% of the respondents had four psychological crisis states. Third, those with 56–65 years of age, equal or below high school and PhD, with monthly family incomes of ¥50,000–¥100,000 and living in the county and city areas have relatively high levels of psychological crisis.

Originality/value

This study enriches the research on the evolution of the psychological crisis in terms of structure and periods. This study also provides substantial evidence for hierarchical intervention and differentiated intervention of psychological crisis.

Details

Chinese Management Studies, vol. 17 no. 1
Type: Research Article
ISSN: 1750-614X

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Article
Publication date: 24 April 2024

Dejing Zhou, Yanming Xia, Zhiming Gao and Wenbin Hu

This study aims to investigate the influence mechanism of brazing and aging on the strengthening and corrosion behavior of novel multilayer sheets (AA4045/AA7072/AA3003M/AA4045).

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Abstract

Purpose

This study aims to investigate the influence mechanism of brazing and aging on the strengthening and corrosion behavior of novel multilayer sheets (AA4045/AA7072/AA3003M/AA4045).

Design/methodology/approach

Polarization curve tests, immersion experiments and transmission electron microscopy analysis were used to study the corrosion behavior and tensile properties of the sheets before and after brazing and aging.

Findings

The strength of the sheet is weakened after brazing due to brittle eutectic phases, and recovered after aging due to enhanced precipitation strengthening in the AA7072 interlayer. The core of nonbrazed sheets cannot be protected due to the significant galvanic coupling effect between the intermetallic particles and the substrate. Brazing and aging treatments promote the redissolved of second phased and limit corrosion along the eutectic region in the clad, allowing the core to be protected.

Originality/value

AA7xxx alloy was added to conventional brazed sheets to form a novel Al alloy composite sheet with AA4xxx/AA7xxx/AA3xxx structure. The strengthening and corrosion mechanism of the sheet was proposed. The added interlayer can sacrificially protect the core from corrosion and improves strength after aging treatment.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 4
Type: Research Article
ISSN: 0003-5599

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