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Article
Publication date: 19 December 2018

Gang Zhao

The paper aims to use aluminium alloy to substitute steel as the main material of ultra-precision hydro-static bearing system for an ultra-precision plastic electronics production…

86

Abstract

Purpose

The paper aims to use aluminium alloy to substitute steel as the main material of ultra-precision hydro-static bearing system for an ultra-precision plastic electronics production system to lower the manufacturing cost. The total cost of diamond turning and nickel-based electroless coating of an aluminium alloy bearing is expected to be less than the cost of manufacturing a stainless steel bearing.

Design/methodology/approach

The paper used a large amount of theoretical calculation to obtain optimal specifications of the bearing system. ANSYS modelling was selected to simulate the deflection of the bearing shaft under high oil pressure. Hundreds of measurements were conducted after the bearing had been manufactured.

Findings

The paper provides industrial application insights on using aluminium alloy with a high-quality nickle-based electroless coating as a successful substitution of stainless steel. This created a more economic hydro-static bearing system.

Research limitations/implications

Because of the time limit, different rotational speed tests shall be conducted in the future.

Practical implications

The paper provides implications for the application of nickel-based electroless coating to improve the surface property and bending strength of aluminium alloy, as well as classifying ultra-precision diamond turning as an economic finishing process.

Originality/value

This paper has identified the importance of aluminium alloy with a nickel-based electroless coating as the substitution of stainless steel in a precision hydro-static bearing system.

Details

Industrial Lubrication and Tribology, vol. 71 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 January 2019

Guo-yuan Zhang, Jia-qi Dang, Wei-gang Zhao and Xiu-tian Yan

The serious friction and wear problem occurs on the mechanical seal’s faces during the start-up stage of the high-speed turbopump for a liquid rocket engine. This paper aims to…

363

Abstract

Purpose

The serious friction and wear problem occurs on the mechanical seal’s faces during the start-up stage of the high-speed turbopump for a liquid rocket engine. This paper aims to propose a kind of thick metal alloy coatings on the surface of the seal’s rotor so as reduce the friction and wear.

Design/methodology/approach

With the pin-disk (the graphite pin and the disk with the metal coating) tribology-tester, the tribological behaviors of four metal coatings are investigated. The special friction coefficients under the dry friction, boundary friction and different temperatures of water-lubricated conditions were obtained.

Findings

The test results show that the thick metal coating has a good performance of the wear resistance and friction reduction; and the friction coefficients of a Sn-Sb-Cu coating under the dry friction and water-lubricated conditions are 0.377 and 0.043, respectively, and the corresponding mass wear volumes are only 2.74 and 0.81 mg, respectively.

Originality/value

The thick metal coating scheme for the mechanical seal’s faces might lend itself to the harsh working conditions of the low-viscosity liquid rocket engine.

Details

Industrial Lubrication and Tribology, vol. 71 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Open Access. Open Access
Article
Publication date: 23 January 2025

Wanru Xie, Yixin Zhao, Gang Zhao, Fei Yang, Zilong Wei and Jinzhao Liu

High-speed turnouts are more complex in structure and thus may cause abnormal vibration of high-speed train car body, affecting driving safety and passenger riding experience…

27

Abstract

Purpose

High-speed turnouts are more complex in structure and thus may cause abnormal vibration of high-speed train car body, affecting driving safety and passenger riding experience. Therefore, it is necessary to analyze the data characteristics of continuous hunting of high-speed trains passing through turnouts and propose a diagnostic method for engineering applications.

Design/methodology/approach

First, Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) is performed to determine the first characteristic component of the car body’s lateral acceleration. Then, the Short-Time Fourier Transform (STFT) is performed to calculate the marginal spectra. Finally, the presence of a continuous hunting problem is determined based on the results of the comparison calculations and diagnostic thresholds. To improve computational efficiency, permutation entropy (PE) is used as a fast indicator to identify turnouts with potential problems.

Findings

Under continuous hunting conditions, the PE is less than 0.90; the ratio of the maximum peak value of the signal component to the original signal peak value exceeded 0.7, and there is an energy band in the STFT time-frequency map, which corresponds to a frequency distribution range of 1–2 Hz.

Originality/value

The research results have revealed the lateral vibration characteristics of the high-speed train’s car body during continuous hunting when passing through turnouts. On this basis, an effective diagnostic method has been proposed. With a focus on practical engineering applications, a rapid screening index for identifying potential issues has been proposed, significantly enhancing the efficiency of diagnostic processes.

Details

Railway Sciences, vol. 4 no. 1
Type: Research Article
ISSN: 2755-0907

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Article
Publication date: 2 January 2025

Gang Zhao, Jianhao Zhang and Wanyi Chen

Low-carbon city policies (LCCP) are crucial environmental regulatory frameworks driving China’s transition toward a low-carbon economy. This study investigated the impact of LCCP…

33

Abstract

Purpose

Low-carbon city policies (LCCP) are crucial environmental regulatory frameworks driving China’s transition toward a low-carbon economy. This study investigated the impact of LCCP on enterprise digital transformation (EDT).

Design/methodology/approach

This study employed a staggered difference-in-differences model for Chinese listed companies from 2007 to 2021. It also used a cross-sectional model for further analysis.

Findings

We found that the implementation of LCCP can promote EDT. This impact was more pronounced among enterprises with greater media attention in high-energy-consumption industries and well-developed economic areas.

Practical implications

This study has practical implications for the LCCP, as it evaluates the consequences of macro-level LCCP on micro-level corporate economic consequences. It provides an important reference for developing countries to implement LCCP and promote green industry upgrading.

Originality/value

This study broadens the impact of the LCCP, providing valuable insights into substantiating carbon neutrality goals and fostering the influencing factors of EDT.

Details

International Journal of Emerging Markets, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1746-8809

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Article
Publication date: 5 February 2024

Yong Liu, Chang-Xue Lin and Gang Zhao

The paper attempts to discuss the optimal pricing decisions under the decentralized and centralized decision and analyze the influence of online reviews and in-sale service on…

357

Abstract

Purpose

The paper attempts to discuss the optimal pricing decisions under the decentralized and centralized decision and analyze the influence of online reviews and in-sale service on dual-channel supply chain. Finally, the authors design a two-part tariff coordination mechanism.

Design/methodology/approach

To deal with this pricing conflict problems of dual-channel supply chain consisting of dominant manufacturer and a retailer, considering the fact that online reviews and in-sale service are important factors on consumers’ purchase decisions, the authors establish some basic models and exploit them to discuss the optimal pricing decisions under the decentralized and centralized decision and analyze the influence of online reviews and in-sale service on dual-channel supply chain. Finally, the authors design a profit-sharing coordination mechanism.

Findings

The results show that the optimal online direct selling price is positively correlated with product perceived quality obtained from online reviews and negatively correlated with the in-sale service. The traditional retail price is positively correlated with the in-sale service and weakly correlated with online reviews. For the manufacturer and retailer, whether decentralized decision or coordination contract, their profits increase with the increase of the in-sale service in a certain range and quality perceived from spontaneous online reviews. Online reviews and in-sale service are important factors on consumers’ purchase decisions. Positive in-sale services and online reviews can provide consumers with a better shopping experience, thereby promoting their enthusiasm for shopping and improving their quality of life. The two-part tariff coordination mechanism improves the profits of the manufacturer and the traditional retailer, respectively, through the transfer fee.

Originality/value

The proposed approach can well analyze the channel conflicts and pricing problems between retailers and manufacturers with respect to product offline price and online price. The analysis and results can inform decision-making for manufacturers and retailers.

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Article
Publication date: 7 November 2022

Shangkun Liang, Fu Xin, Junli Yu and Gang Zhao

The political influence on the determinants of capital structure has been under-researched for a long time. Taking the turnover of secretary of municipal committee as a political…

452

Abstract

Purpose

The political influence on the determinants of capital structure has been under-researched for a long time. Taking the turnover of secretary of municipal committee as a political factor in China, this paper studies the effect of local government officials' turnover on firm's capital structure.

Design/methodology/approach

Starting with all A-shares listed firms in the Shanghai and Shenzhen Stock Exchanges from 2001 to 2018, this paper implements the OLS estimation, staggered difference-in-difference approach to investigate the effects of political turnover on the choice of capital structure.

Findings

The results show that, driven by government officials' turnover, firms will significantly reduce their leverage. When comparing between formal finance (bank loans) and informal finance (payables), the reduction of capital structure is mainly driven by banks, not by suppliers. Furthermore, two possible channels have been investigated. First, the reduction effects are mainly driven by the SOEs when classifying the types of corporate ownership into SOEs and non-SOEs. Second, the reduction effects exist in areas with the more intense government intervention when considering the heterogeneity of the development of institutional environment in provinces.

Originality/value

This paper first contributes to the literature on the determinants of corporate choice on capital structure. Second, this paper enriches the studies on the economic consequences of local government officials' turnover.

Details

Asian Review of Accounting, vol. 31 no. 1
Type: Research Article
ISSN: 1321-7348

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Article
Publication date: 4 October 2022

Gang Zhao, Xin Yu and Kailun Ni

The findings suggest that reducing information processing costs as a result of better transportation is an important ingredient in promoting the pricing of firm-specific…

234

Abstract

Purpose

The findings suggest that reducing information processing costs as a result of better transportation is an important ingredient in promoting the pricing of firm-specific information. This study aims to discuss the aforementioned issue.

Design/methodology/approach

The authors adopt a difference-in-difference (DID) research design to examine the impact of information processing costs on stock price synchronicity with a sample of firms listed in the Chinese A-share market during 2007 and 2017.

Findings

This paper shows that the launch of the high-speed railway (hereafter HSR) in China is associated with lower stock price synchronicity, consistent with the theory that the HSR reduces investors’ information processing costs (cost of monitoring, acquiring and analyzing firm disclosures). This effect is more pronounced for companies located in remote areas than for those located in large cities. Further tests show that the negative association between the launch of HSR and stock price synchronicity is stronger for companies with higher information asymmetries, proxied by higher equity concentration, higher complexity and lower internal control quality.

Originality/value

This study contributes to the literature in the following three ways. First, prior literature relates the effects of geographic distance to information transmission and information asymmetry between insiders and outside investors (e.g. Coval and Moskowitz, 2001; Kang and Kim, 2008; Malloy, 2005). The authors supplement the literature by providing new empirical evidence from an exogenous shock (natural experiment), that is, the launch of HSR, that facilitates transportation and reduces information transmission costs. Second, prior studies have shown that new airline routes that facilitate transportation improve investment and productivity (e.g. Bernstein et al., 2016; Giroud, 2013). The authors extend this stream of studies by showing that the development of HSR networks reduces information processing costs, and promotes the incorporation of firm-specific information in the asset pricing. More importantly, in this study, the authors explicitly incorporate disclosure processing costs theory into our framework thus enhancing our understanding of how and why improvements in transport relate to better market outcomes.

Details

Asian Review of Accounting, vol. 31 no. 1
Type: Research Article
ISSN: 1321-7348

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Article
Publication date: 6 May 2014

Taiwen Feng and Gang Zhao

The purpose of this paper is to examine the effects of top management support (TMS) and inter-organizational relationships (IORs) on external involvement (EI), and their…

1670

Abstract

Purpose

The purpose of this paper is to examine the effects of top management support (TMS) and inter-organizational relationships (IORs) on external involvement (EI), and their differences across different ownerships.

Design/methodology/approach

To test the research hypotheses, structural equation modeling was conducted using data from 176 Chinese manufacturing firms.

Findings

TMS enhances relationship with customers and relationship with suppliers. Relationship with customers increases the degree of customer involvement, while relationship with suppliers increases the degree of supplier involvement. In addition, TMS improves customer involvement while does not improve supplier involvement directly. A further analysis reveals that the relationship between TMS and supplier involvement is partially mediated by relationship with suppliers in Chinese-controlled firms, whereas it is completely mediated by relationship with suppliers in foreign-controlled firms. Moreover, the effect of relationship with suppliers on supplier involvement is stronger in foreign-controlled firms than in Chinese-controlled firms.

Research limitations/implications

This study employed perceptual data from a single respondent in each firm. In addition, the data used in this study were collected from one side of the dyad: the manufacturers.

Practical implications

Both Chinese-controlled and foreign-controlled firms should get support from top management and develop close relationship with customers and suppliers to improve EI.

Originality value

This study extends our knowledge in the field by examining how TMS and prior history of IORs can improve the degree of EI.

Details

Industrial Management & Data Systems, vol. 114 no. 4
Type: Research Article
ISSN: 0263-5577

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Article
Publication date: 1 April 2004

Weishi Li, Shuhong Xu and Gang Zhao

To retrieve the geometric information contained in CT images, a surface reconstruction method, which is based on the similarity between the corresponding contours of adjacent…

550

Abstract

To retrieve the geometric information contained in CT images, a surface reconstruction method, which is based on the similarity between the corresponding contours of adjacent sections, is presented in this paper. The correspondence of the contours of adjacent sections is determined by incorporating the topological rules and overlaps of the convex hulls of the contours. Then, the similar vertices of the corresponding contours are matched using a two‐phase strategy, consisting of overall matching followed by local matching. Dissimilar portions are extracted to construct the triangulable spatial dissimilar polygons. Finally, triangular meshes interpolating the contours are obtained by triangulating the dissimilar polygons and similar portions separately. The reconstructed surface models can be used in rapid prototyping as well as visualization. Experimental results demonstrate the validity of the method in reconstructing the surface from severe dissimilar contours.

Details

Rapid Prototyping Journal, vol. 10 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 4 March 2014

Zhang Guo-yuan, Wei-gang Zhao and Yan Xiu Tian

A new type of hydrostatic and hydrodynamic non-contacting face seals has been designed to meet the requirements of lower leakage, longer life and more repeatedly start and stop on…

333

Abstract

Purpose

A new type of hydrostatic and hydrodynamic non-contacting face seals has been designed to meet the requirements of lower leakage, longer life and more repeatedly start and stop on shaft seals raised by liquid rocket engine turbopumps. And an experimental study on the performance of the face seal in the actual liquid oxygen turbopump was completed where low-viscosity water was selected as the seal fluid for the sake of safety. The paper aims to discuss these issues.

Design/methodology/approach

Different performances of face seals under preset conditions were obtained by repeatedly running tests, and the main performance parameters encompass leakage, fluid film pressure between the faces, operating power, face temperature, and so on.

Findings

The results indicate that the designed face seal has a smaller amount of leakage, with a minimum value of 3 ml/s. Furthermore, the designed face seal has been proved to demand lower operating power. Since its operating power changes slightly with different sealed fluid pressures, the new seal can be deployed in the harsh working condition with high pressure or with high speed (greater than 20,000 rpm). However, one proviso is that when liquid is employed as the seal fluid, the groove depth should be relatively deeper (greater than 10 μm).

Research limitations/implications

In response to future engineering requirements, study on the controllable spiral-groove face seals to improve the current design is being conducted.

Originality/value

The advancement of such non-contacting face seals proffers important insights to the design of turbo-pump shaft seal in a new generation of liquid rocket engine with regard to the requirement of frequent start and stop as well as long life on it.

Details

Industrial Lubrication and Tribology, vol. 66 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

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