Search results

1 – 10 of 43
Article
Publication date: 19 July 2019

Biao Zhao, Wenfeng Ding, Weijie Kuang and Yucan Fu

This paper aims to evaluate the influence of molybdenum disulfide (MoS2) concentrations (5, 7.5, 10, 12.5 and 15 Wt.%) on the microstructure and tribological property of…

Abstract

Purpose

This paper aims to evaluate the influence of molybdenum disulfide (MoS2) concentrations (5, 7.5, 10, 12.5 and 15 Wt.%) on the microstructure and tribological property of the self-lubrication cubic boron nitride (CBN) abrasive composites.

Design/methodology/approach

Three point bending method and rotating sliding test are used to evaluate the flexural strength and tribological property of self-lubricating CBN abrasive composites. Microstructure, wear morphology of the ball and scratch are supported by scanning electron microscopy, optical microscope and three-dimensional confocal microscopy, etc.

Findings

The MoS2 concentration has a significant influence on the interface microstructure between CBN abrasives and matrix alloys, and thus, affects the flexural strength of CBN abrasive composites. The grain fracture modes of CBN abrasive composites are transformed from the transgranular fracture into intergranular fracture as the MoS2 concentrations increase. Additionally, the friction coefficient of as-sintered samples decreases with the MoS2 concentrations. The MoS2 concentrations of 10 Wt.% are final determined to fabricate self-lubricating composites in basis of the mechanical and lubricating property.

Originality/value

The ball is fabricated under vacuum sintering process. The tribological property of self-lubricating CBN abrasive composites is evaluated in terms of the friction coefficient and morphologies of the ball and scratches after rotating sliding tests.

Details

Industrial Lubrication and Tribology, vol. 71 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 17 June 2022

Biao Li, Jun Sun, Hu Wang and Xiao Zhang

Under the action of many factors, the shaft of the shaft-journal bearing system inevitably moves along the axis direction at work, which will lead to the axial movement of…

Abstract

Purpose

Under the action of many factors, the shaft of the shaft-journal bearing system inevitably moves along the axis direction at work, which will lead to the axial movement of journal in the bearing. However, at present, only the dynamic and squeezing effects caused by the relative rotation and squeezing motion between the journal and the bearing surfaces are considered in the lubrication analysis of misaligned journal bearing and the axial movement of journal in the actual use of bearing is not considered. The purpose of this paper is to analyze the lubrication of journal bearing considering the axial movement of journal.

Design/methodology/approach

Taking the shaft-journal bearing system as the research object, a hydrodynamic lubrication model of journal bearing is established considering the axial movement and misalignment of journal. The finite difference method is used to solve the Reynolds equation for the lubrication analysis.

Findings

The axial movement of journal has a significant influence on the lubrication characteristics of misaligned journal bearing. The larger the misalignment angles of journal or the eccentricity of bearing, the greater the influence of the axial movement of journal on the lubrication performance of bearing. The lower the speed of bearing or the smaller the clearance of bearing, the more significant the influence of the axial movement of journal on the lubrication performance of bearing is.

Originality/value

The influence of the axial movement of journal on the lubrication performance of journal bearing is studied under different misalignment angles of journal, working conditions and clearances of bearing. The results of this paper are helpful to the design and research of the lubrication performance of journal bearing.

Details

Industrial Lubrication and Tribology, vol. 74 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 5 June 2017

Biao Zhang, Zetian Fu, Jieqiong Wang, Xiaolin Tang, Yousen Zhao and Lingxian Zhang

Farmers’ selection of vegetable marketing channels directly affects their income and is important to stable vegetable supply and food control. The purpose of this paper is…

Abstract

Purpose

Farmers’ selection of vegetable marketing channels directly affects their income and is important to stable vegetable supply and food control. The purpose of this paper is to investigate the farmers’ selection behavior of vegetable marketing channels, and to determine the key factors which affected farmer’ decision making.

Design/methodology/approach

A total of 191 valid questionnaires were collected from 50 villages in seven main vegetable production districts in Beijing urban areas from September to December 2015, yielding a response rate of 86.8 percent. The multinomial logit model was used for analysis in this study.

Findings

The results revealed that the farmers mainly selected farmers’ market, cooperative, and wholesaler to sell their vegetables, which comprised 96.57 percent of total vegetable sales. Estimation results showed that cooperative, vegetable acreage, price satisfaction, and slow sales were most important factors which influence positively the probability of opting to sell vegetables at a cooperative rather than at the farmer’s market. For wholesalers, gender of the household head and cooperative had most significantly negative effect, and age had a positive impact on farmer’s choice of market channels.

Originality/value

The results and implications obtained in the present study could help policymakers to establish a scientific-based and reasonable policy to encourage vegetable producers to participate in the circulation of vegetables in Beijing and guarantee their income in vegetable supply chain. The suggestions of this study could also be used for the improvement of the vegetable sector in other cities facing similar issues.

Details

British Food Journal, vol. 119 no. 6
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 23 May 2022

Biao Ma, Qian Wang, Changsong Zheng, Liang Yu, Guoyu Wang and Liangjie Zheng

This paper aims to explore the effect of automatic transmission fluid (ATF) temperature on the dynamic friction-wear properties of the friction component in a wet…

Abstract

Purpose

This paper aims to explore the effect of automatic transmission fluid (ATF) temperature on the dynamic friction-wear properties of the friction component in a wet multi-disc clutch during the running-in process.

Design/methodology/approach

The running-in evolution was explored in terms of global friction performance and instantaneous friction characteristics. The variation of friction torque of the initial 300 engagement cycles was obtained by wet-clutch tests. Finally, an optical microscope was used to detect the wear mechanism of friction surfaces.

Findings

The ATF temperature showed a significant effect on the friction-wear performance in the clutch running-in process. The mean coefficient of friction decreased with the increase of the ATF temperature and decreased rapidly in the approximately initial 60 clutch engagements. The higher the ATF temperature was, the thinner the ATF film was, and more asperity summits were cut, thus leading to a smoother surface. Considering the slightly instantaneous friction fluctuation and the wear performance, a proper ATF temperature is necessary.

Originality/value

The results provide theoretical guidance for selecting the optimal ATF temperature during the running-in process.

Details

Industrial Lubrication and Tribology, vol. 74 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 6 June 2016

Chengyuan Wang, Biao Luo, Yong Liu and Zhengyun Wei

The paper aims to study the relationship between executives’ perceptions of environmental threats and innovation strategies and investigate the moderating effect of…

Abstract

Purpose

The paper aims to study the relationship between executives’ perceptions of environmental threats and innovation strategies and investigate the moderating effect of contextual factor (i.e. organizational slack) on such relations. It proposes a dualistic relationship between executives’ perceptions of environmental threats and innovation strategies, in which different perceptions of environmental threats will lead to corresponding innovation strategies, and dyadic organizational slack can promote such processes.

Design/methodology/approach

The paper is based on a survey with 163 valid questionnaires, which were all completed by executives. Hierarchical ordinary least-squares regression analysis is used to test the hypotheses proposed in this paper.

Findings

The paper provides empirical insights about that executives tend to choose exploratory innovation when they perceive environmental changes as likely loss threats, yet adopt exploitative innovation when perceiving control-reducing threats. Furthermore, unabsorbed slack (e.g. financial redundancy) positively moderates both relationships, while absorbed slack (e.g. operational redundancy) merely positively influences the relationship between the perception of control-reducing threats and exploitative innovation.

Originality/value

The paper bridges the gap between organizational innovation and cognitive theory by proposing a dualistic relationship between executives’ perceptions of environmental threats and innovation strategies. The paper further enriches innovation studies by jointly considering both subjective and objective influence factors of innovation and argues that organizational slack can moderate such dualistic relationship.

Details

Nankai Business Review International, vol. 7 no. 2
Type: Research Article
ISSN: 2040-8749

Keywords

Article
Publication date: 11 July 2019

Biao Ma, Liang Yu, Man Chen, He Yan Li and Liang Jie Zheng

This paper aims to investigate the thermal characteristics of the clutch hydraulic system under various oil flow conditions. Increasing the oil flow is one of the most…

Abstract

Purpose

This paper aims to investigate the thermal characteristics of the clutch hydraulic system under various oil flow conditions. Increasing the oil flow is one of the most important approaches to reduce the clutch temperature. However, the effect of the oil flow on the clutch temperature remains to be explored.

Design/methodology/approach

The thermal resistance network model and the lumped parameter method are used to study the thermal characteristics of the clutch hydraulic system. The predicted temperature variations of the clutch and the oil are compared with experimental data.

Findings

Results demonstrate that the larger the friction power is, the higher the temperatures of the clutch and the oil are. However, the temperature growth rates of the clutch and oil present different trends: the former decreases gradually and the latter increases constantly. Additionally, increasing the oil flow within a certain range gives rise to the decrease of clutch temperature and the increase of oil temperature; nevertheless, their variation trends are gradually weakening. When the oil flow is large enough, it brings a slight effect on the clutch temperature rise.

Originality/value

This paper extends the knowledge into the oil flow supply of the clutch hydraulic system. The conclusions can provide a theoretical guidance for the oil management of the transmission system. Additionally, the thermal resistance network model is also effective and efficient for other hydraulic equipment to predict the temperature variation.

Details

Industrial Lubrication and Tribology, vol. 71 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 25 June 2021

Xiaoping Zhuang, Li Lin, Rongteng Zhang, Jun (Justin) Li and Biao He

This study attempts to explore major attributes of food delivery applications in consideration of their impacts upon perceived service quality, satisfaction and usage…

Abstract

Purpose

This study attempts to explore major attributes of food delivery applications in consideration of their impacts upon perceived service quality, satisfaction and usage intention. A multi-group analysis is performed to examine the hypothesized relationships in the structural models for the millennials and non-millennials.

Design/methodology/approach

The data was collected from 311 food delivery application users. The structural equation model (SEM) was designed to examine the interrelationships among variables.

Findings

The findings indicate that five salient dimensions that include ease of use, facility aesthetics, trustworthiness, value for money and product portfolio have a significant impact on overall service quality. Results further demonstrate that differences in generational difference partially moderate the relationship between each attribute of the food delivery application service quality as well as overall service quality.

Originality/value

The rapid evolution of the Internet and mobile communication has resulted in the proliferation of food delivery applications in China. However, to the best of our knowledge, only a few studies have focused on measuring the key dimension of service quality of food delivery applications.

Details

British Food Journal, vol. 123 no. 12
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 6 August 2019

Jianpeng Wu, Biao Ma, Heyan Li and Chengnan Ma

The purpose of this paper is to study friction and wear properties of three types of steels against paper-based friction disc, including 65Mn, 20#steel and 30CrAl, so as…

121

Abstract

Purpose

The purpose of this paper is to study friction and wear properties of three types of steels against paper-based friction disc, including 65Mn, 20#steel and 30CrAl, so as to obtain the appropriate working conditions for different friction materials in the transmission system.

Design/methodology/approach

Based on actual working conditions, pin-on-disc tests are conducted on a universal material tester. The two evaluation indexes, including average friction coefficient and variation coefficient, are introduced to analyze the different friction properties among three types of steel. Furthermore, the temperature-dependent wear pattern and wear depth are subsequently studied.

Findings

The results show that 65Mn is more suitable for working under heavy load and low velocity, but 30CrAl and 20#steel are suitable for working under light load and high velocity. Moreover, wear primarily occurs on paper-based material and peaks at about 325.

Practical implications

This research of different materials and friction property for friction pairs is helpful to improve the performance and prolong the service life of transmission systems.

Originality/value

Suitable working conditions of different friction materials are obtained, and the correlation between wear and decomposition in high temperature is verified.

Details

Industrial Lubrication and Tribology, vol. 71 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 7 March 2016

Yu Zhao, Guoyu Wang and Biao Huang

The purpose of this paper is to assess the predictive capability of the streamline curvature correction model (CCM) and investigate the unsteady vortex behavior of the…

Abstract

Purpose

The purpose of this paper is to assess the predictive capability of the streamline curvature correction model (CCM) and investigate the unsteady vortex behavior of the cloud cavitating flows around a hydrofoil.

Design/methodology/approach

The design of the paper is based on introducing the curvature correction method to the original k-ε model. Calculations of unsteady cloud cavitating flows around a Clark-Y hydrofoil are performed using both the CCM and the baseline model.

Findings

Compared with the baseline model, better agreements are observed between the predictions of the CCM model and experimental data, especially the cavity shedding process. Based on the computations, it is demonstrated that streamline curvature correction of the CCM model can effectively decrease predicted turbulence kinetic energy and eddy viscosity in cavity shedding region. This leads to the better prediction for the recirculation zone located downstream of the attached cavity, and dynamics of this recirculation zone contribute to the formation and development of the re-entrant jet.

Originality/value

The authors apply streamline curvature correction to the calculations of unsteady cloud cavitating flows and discuss the interactions between the cavitation unsteadiness and vortex structures to get an insight of the correction mechanics.

Details

Engineering Computations, vol. 33 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 6 May 2014

Biao Sun and Yi-Ju Lo

The purpose of this paper is to define co-exploitation, co-exploration, and alliance ambidexterity from the perspective of organizational learning; to analyze how…

1213

Abstract

Purpose

The purpose of this paper is to define co-exploitation, co-exploration, and alliance ambidexterity from the perspective of organizational learning; to analyze how knowledge bases, structural arrangements, and control mechanisms of R&D alliances influence co-exploitation and co-exploration; and to discuss how to achieve alliance ambidexterity by managing paradoxes around knowledge bases, structural arrangements, and control mechanisms.

Design/methodology/approach

This is a conceptual paper focussing on how to balance exploitation and exploration at the alliance level through managing three paradoxes of cooperation: similarity vs complementarity, integration vs modularity, and contracts vs trust.

Findings

While technological similarity, structural integration, and contracts are more likely to promote co-exploitation, technological complementarity, structural modularity, and trust are more likely to facilitate co-exploration. Alliance ambidexterity, which is beneficial for alliance performance, derives from either the combination of technological complementarity, structural integration, and contracts, or the combination of technological similarity, structural modularity, and trust temporally.

Research limitations/implications

Researchers should analyze the possibility of building alliance ambidexterity in other types of interorganizational relationships, and find other possible antecedents of interorganizational learning.

Practical implications

Managers should not simply treat R&D alliances as one of exploratory interorganizational relationships, but pay equal attention to co-exploitation and co-exploration. To achieve this balance, practitioners should combine technological complementarity with structural integration and contracts, or integrate technological similarity with structural modularity and trust.

Originality/value

This paper is one of the first contributions that analyze how an R&D alliance could gain its ambidexterity through the management of nested cooperation paradoxes.

Details

European Journal of Innovation Management, vol. 17 no. 2
Type: Research Article
ISSN: 1460-1060

Keywords

1 – 10 of 43