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Article
Publication date: 13 September 2018

Miao Li, Bi Qing Chen, Min He, Tongtong Xiong and Lixia Gao

This paper aims to obtain rare earth magnesium alloy with good adhesion and corrosion resistance.

174

Abstract

Purpose

This paper aims to obtain rare earth magnesium alloy with good adhesion and corrosion resistance.

Design/methodology/approach

In 353 K oil bath, cyclic voltammetry was used to study the electrochemical behavior of Pr(III), Mg(II) and Ni(II) in choline chloride-urea ionic liquid. The constant potential method was adopted for electrodeposition of Pr-Mg-Ni ternary alloy films. The content of Pr in the Pr-Mg-Ni alloy films changes with respect to the deposition potential, deposition time and concentration ratio of Pr3+:Mg2+:Ni2+. Response surface methodology was applied to optimize the conditions for obtaining high-quality deposition films.

Findings

The results showed that the reaction of Ni(II) to Ni is irreversible; this result can be verified by Tafel polarization curve and chronocoulometry curve. Its transfer coefficient on the platinum electrode of 0.32 and diffusion coefficient is 1.0510−6 cm2.s−1. Mg(II) and Pr(III) cannot solely be reduced to their elemental form, but they can be induced via codeposition by Ni(II). The result shows that under a voltage of −1.00 V, the alloy coating with even structure is obtained when the concentration ratio of Pr3+:Mg2+:Ni2+ is 1:1:1 and the deposition time is 20 min. Scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and other analyses revealed that the alloy coating is amorphous. Polarization curves of the cathode are tested, which manifest the lowest corrosion current density, stating which has good corrosion performance in alkaline solution and NaCl solution; this can be attributed to its dense film structure and good combination with the substrate.

Originality/value

It provides some technology for the production of corrosion-resistant materials.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Available. Open Access. Open Access
Article
Publication date: 29 May 2024

Lixia Sun, Yuanwu Cai, Di Cheng, Xiaoyi Hu and Chunyang Zhou

Under the high-speed operating conditions, the effects of wheelset elastic deformation on the wheel rail dynamic forces will become more notable compared to the low-speed…

243

Abstract

Purpose

Under the high-speed operating conditions, the effects of wheelset elastic deformation on the wheel rail dynamic forces will become more notable compared to the low-speed condition. In order to meet different analysis requirements and selecting appropriate models to analyzing the wheel rail interaction, it is crucial to understand the influence of wheelset flexibility on the wheel-rail dynamics under different speeds and track excitations condition.

Design/methodology/approach

The wheel rail contact points solving method and vehicle dynamics equations considering wheelset flexibility in the trajectory body coordinate system were investigated in this paper. As for the wheel-rail contact forces, which is a particular force element in vehicle multibody system, a method for calculating the Jacobian matrix of the wheel-rail contact force is proposed to better couple the wheel-rail contact force calculation with the vehicle dynamics response calculation. Based on the flexible wheelset modeling approach in this paper, two vehicle dynamic models considering the wheelset as both elastic and rigid bodies are established, two kinds of track excitations, namely normal measured track irregularities and short-wave irregularities are used, wheel-rail geometric contact characteristic and wheel-rail contact forces in both time and frequency domains are compared with the two models in order to study the influence of flexible wheelset rotation effect on wheel rail contact force.

Findings

Under normal track irregularity excitations, the amplitudes of vertical, longitudinal and lateral forces computed by the flexible wheelset model are smaller than those of the rigid wheelset model, and the virtual penetration and equivalent contact patch are also slightly smaller. For the flexible wheelset model, the wheel rail longitudinal and lateral creepages will also decrease. The higher the vehicle speed, the larger the differences in wheel-rail forces computed by the flexible and rigid wheelset model. Under track short-wave irregularity excitations, the vertical force amplitude computed by the flexible wheelset is also smaller than that of the rigid wheelset. However, unlike the excitation case of measured track irregularity, under short-wave excitations, for the speed within the range of 200 to 350 km/h, the difference in the amplitude of the vertical force between the flexible and rigid wheelset models gradually decreases as the speed increase. This is partly due to the contribution of wheelset’s elastic vibration under short-wave excitations. For low-frequency wheel-rail force analysis problems at speeds of 350 km/h and above, as well as high-frequency wheel-rail interaction analysis problems under various speed conditions, the flexible wheelset model will give results agrees better with the reality.

Originality/value

This study provides reference for the modeling method of the flexible wheelset and the coupling method of wheel-rail contact force to the vehicle multibody dynamics system. Furthermore, by comparative research, the influence of wheelset flexibility and rotation on wheel-rail dynamic behavior are obtained, which is useful to the application scope of rigid and flexible wheelset models.

Details

Railway Sciences, vol. 3 no. 3
Type: Research Article
ISSN: 2755-0907

Keywords

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Book part
Publication date: 20 January 2021

Yao Lixia

Abstract

Details

Energy Security in Times of Economic Transition: Lessons from China
Type: Book
ISBN: 978-1-83982-465-4

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Book part
Publication date: 20 January 2021

Yao Lixia

Abstract

Details

Energy Security in Times of Economic Transition: Lessons from China
Type: Book
ISBN: 978-1-83982-465-4

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Book part
Publication date: 20 January 2021

Yao Lixia

Abstract

Details

Energy Security in Times of Economic Transition: Lessons from China
Type: Book
ISBN: 978-1-83982-465-4

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Article
Publication date: 18 November 2013

Gucheng Li, Zhongchao Feng, Liangzhi You and Lixia Fan

Whether there exists an inverse relationship (IR) between farm size and its efficiency remains a hotly debated question among agricultural economists. In most studies to date…

915

Abstract

Purpose

Whether there exists an inverse relationship (IR) between farm size and its efficiency remains a hotly debated question among agricultural economists. In most studies to date, farm efficiency is measured by land productivity. Thus, the IR actually measures the relationship between farm size and land productivity. The purpose of this paper is to examine and understand the IR from a novel angle by using multiple definitions of farm efficiency indicators like labor productivity, profit ratio, total factor productivity (TFP) and technical efficiency (TE).

Design/methodology/approach

By using the farm-level panel data from Hubei province in China from 1999 to 2003, this paper employs the two-way fixed effect model of panel data and the stochastic frontier analysis of Battese and Coelli model to investigate the relationship between farm size and its production efficiency derived from the multiple definitions of production efficiency indicators including land productivity, labor productivity, profit ratio, TFP and TE.

Findings

The study confirmed the IR between land productivity and farm size, as in many formal studies. However, the relationship between farm size and other agricultural efficiency indicators may be positive, negative or uncorrelated at, depending on how the farm efficiency is defined. Therefore, the paper concluded that the relationship between farm size and its production efficiency is mixed. This paper provides economic explanations for the IR through the comprehensive study using the expansion of agricultural efficiency indicators.

Practical implications

Because different agricultural efficiency indicators have different policy implications for China's future agricultural and land policy, the findings have tremendous policy implications, particularly in terms of the current debate on large or small farm development strategy, the also so-called “go big or small” agricultural strategy. In this sense, the Chinese household responsibility system has played a critical role in its agriculture and will continue to play a critical role in terms of social security and social equality. Any reform to this system should proceed with caution.

Originality/value

While most existing studies only try to explain the IR from the perspective of land productivity, this paper attempts to propose a novel angle to examine the IR by using multiple definitions of agricultural efficiency and hopes to find some new conclusions.

Details

China Agricultural Economic Review, vol. 5 no. 4
Type: Research Article
ISSN: 1756-137X

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Article
Publication date: 10 December 2019

Fei Wang, Yuqiang Liu, Yahui Zhang, Yu Gao, Ling Xiao and Chengdong Wu

A robotic wheelchair system was designed to assist disabled people with disabilities to walk.

207

Abstract

Purpose

A robotic wheelchair system was designed to assist disabled people with disabilities to walk.

Design/methodology/approach

An anticipated sharing control strategy based on topological map is proposed in this paper, which is used to assist robotic wheelchairs to realize interactive navigation. Then, a robotic wheelchair navigation control system based on the brain-computer interface and topological map was designed and implemented.

Findings

In the field of robotic wheelchairs, the problems of poor use, narrow application range and low humanization are still not improved.

Originality/value

In the system, the topological map construction is not restricted by the environment structure, which helps to expand the scope of application; the shared control system can predict the users’ intention and replace the users’ decision to realize human-machine interactive navigation, which has higher security, robustness and comfort.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 10 November 2023

Lixia Wang, Yingqian Gu and Wanxin Liu

Under the background of continuous sluggishness of the real economy and expansion of asset sectors, the Chinese economy exists a trend of “from the real to the virtual.” Managing…

222

Abstract

Purpose

Under the background of continuous sluggishness of the real economy and expansion of asset sectors, the Chinese economy exists a trend of “from the real to the virtual.” Managing the corporate financialization is the key to prevent the real economy “from real to virtual.” The paper explores the influence of family involvement on corporate financialization since family firms are an important proportion of real sectors.

Design/methodology/approach

Based on Socioemotional Wealth Theory, this paper makes empirical study using the data of Chinese A-share listed companies from 2008 to 2022 to explore the influence of family involvement on corporate financialization, mainly from the perspectives of family engagement, family identity of CEO and family control power.

Findings

These are the findings: (1) Family engagement will inhibit corporate financialization; (2) Compared with employing external managers, family members acting as CEOs will decrease corporate financialization; (3) The proportion of family ownership is negatively correlated with the level of corporate financialization.

Originality/value

The originality of this paper include these: (1) Analyzing the differences in the financialization of real enterprises with different characteristics and attributes; (2) Expanding the research on the internal motivation of the financialization of the real enterprises, and supplementing the research literature on family firms and corporate financialization; (3) Exploring the internal influence mechanism of financialization of family firms under the background of Chinese culture.

Details

International Journal of Managerial Finance, vol. 20 no. 3
Type: Research Article
ISSN: 1743-9132

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Article
Publication date: 14 November 2023

Yingqian Gu, Wenqi Zhang, Lin Sha and Lixia Wang

This paper aims to explore the impact of corporate financialization (CF) on green innovation (GI) and further disclose the moderating role of CEO’s individual characteristics in…

292

Abstract

Purpose

This paper aims to explore the impact of corporate financialization (CF) on green innovation (GI) and further disclose the moderating role of CEO’s individual characteristics in such relationship from the perspective of corporate governance.

Design/methodology/approach

This paper uses empirical research methods to study the impact of CF on GI based on the evidence from China capital market.

Findings

The findings indicate that: CF has a significant inhibiting effect on GI; female CEOs weaken the inhibiting effect of CF on GI compared to male CEOs; and CEO’s financial background positively moderates the inhibiting effect of CF on GI.

Originality/value

This paper, first, supplements the research literature on the economic consequences of CF and influencing factors of GI in non-financial firms. Then, it opens up the internal impact mechanism of CF on GI, which is moderated by the individual characteristics of corporate CEOs. Finally, it provides important reference for how to suppress CF of non-financial firms, cultivate CEOs that meet the needs of corporate development and promote GI development of enterprises through empirical evidence from China.

Details

Chinese Management Studies, vol. 18 no. 4
Type: Research Article
ISSN: 1750-614X

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Article
Publication date: 6 February 2017

Asli Özdemir and Güzin Özdagoglu

Prediction problems raised in uncertain environments require different solution approaches such as grey prediction models, which consider uncertainty in information and also…

537

Abstract

Purpose

Prediction problems raised in uncertain environments require different solution approaches such as grey prediction models, which consider uncertainty in information and also enable the use of small data sets. The purpose of this paper is to investigate the comparative performances of grey prediction models (GM) and Markov chain integrated grey models in a demand prediction problem.

Design/methodology/approach

The modeling process of grey models is initially described, and then an integrated model called the Grey-Markov model is presented for the convenience of applications. The analyses are conducted on a monthly demand prediction problem to demonstrate the modeling accuracies of the GM (1,1), GM (2,1), GM (1,1)-Markov, and GM (2,1)-Markov models.

Findings

Numerical results reveal that the Grey-Markov model based on GM (2,1) achieves better prediction performance than the other models.

Practical implications

It is thought that the methodology and the findings of the study will be a significant reference for both academics and executives who struggle with similar demand prediction problems in their fields of interest.

Originality/value

The novelty of this study comes from the fact that the GM (2,1)-Markov model has been first used for demand prediction. Furthermore, the GM (2,1)-Markov model represents a relatively new approach, and this is the second paper that addresses the GM (2,1)-Markov model in any area.

Details

Grey Systems: Theory and Application, vol. 7 no. 1
Type: Research Article
ISSN: 2043-9377

Keywords

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