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Article
Publication date: 26 July 2021

Yan Liu, Yanzhen Liu and Guochang Lin

This study aims to investigate the basic mechanical properties of inflatable antenna reflector material under high-low temperatures.

Abstract

Purpose

This study aims to investigate the basic mechanical properties of inflatable antenna reflector material under high-low temperatures.

Design/methodology/approach

Uniaxial tensile tests of Kapton (polyimide) foils were conducted in this paper. Kapton foils with a thickness of 25 µm were used and the strip specimens were manufactured according to the machine direction and the transverse direction of the foils.

Findings

The stress–strain curves of the foils were obtained under ten temperature conditions (−70°C, −40°C, −10°C, 0°C, 20°C, 50°C, 80°C, 110°C, 140°C, 170°C) after uniaxial tensile tests. Generally speaking, such stress–strain curves are highly nonlinear, and Kapton can be classified into some kind of ductile material without obvious yielding point.

Practical implications

The tests results provide a basis for partial coefficients of Kapton foils strength design value, and meanwhile provide basic material data for the extreme temperature field test in orbit for the inflatable antenna structure in the future.

Originality/value

Based on the curve itself and strain energy theory, for the first time the equivalent yielding point was determined and the mechanism of constitutive curve changing with temperature was explained. Based on curves above, tensile strength, elongation at break, equivalent yielding stress, yielding strain and elastic modulus were analyzed and calculated. By analyzing the mechanical parameters above, the fitting formulas with temperature as the variable were given.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 8 June 2012

Ruilin Guo, Qiufang Wu, Yafei Liu and Yanzhen Liu

The purpose of this paper is to attempt to solve a decision‐making problem for breeding target character showed as an interval number.

266

Abstract

Purpose

The purpose of this paper is to attempt to solve a decision‐making problem for breeding target character showed as an interval number.

Design/methodology/approach

A new comprehensive evaluation method was proposed based on similarity‐difference theory and interval number theory. The data from Winter Wheat Group I Variety Regional Test in Henan Province in 2009‐2010 were analysed using the proposed method.

Findings

The results showed that Zhou 99233 was a good variety, Yuxhan No.7, An 05‐28, Xun K8, Jinyumai 378 and Zhoumai 18 were better ones, 08 luo 36, and Xuke 718 ordinary ones, and others worse ones. Based on this, the feasibility of the method was discussed. It showed that the proposed method had some obvious merits, such as arithmetic was simple, operation convenient, flexible and practical, fast and effective, etc.

Practical implications

Application to a living example indicated that its evaluation effect was satisfactory. Consequently, the application prospect of the method will be very vast.

Originality/value

The paper succeeds in solving a decision‐making problem for breeding target character shown as an interval number.

Details

Kybernetes, vol. 41 no. 5/6
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 19 August 2011

Guo Ruilin, Wu Qiufang, Liu Yafei, Liu Yanzhen, Mao Guangzhi and Wang Jinshun

The paper seeks to attempt to solve a decision‐making problem for breeding target character shown as an interval number.

268

Abstract

Purpose

The paper seeks to attempt to solve a decision‐making problem for breeding target character shown as an interval number.

Design/methodology/approach

A new comprehensive evaluation method is proposed based on similarity‐difference theory and interval number theory. Data from Winter Wheat Group I Variety Regional Test in Henan Province in 2009‐2010 were analysed using the proposed method.

Findings

The results showed that Zhou 99233 was a good variety; Yuxhan No. 7, An 05‐28, Xun K8, Jinyumai 378 and Zhoumai 18 were better ones; 08 luo 36,and Xuke 718 ordinary ones, and others worse ones. Based on this, the feasibility of the method was discussed. It showed that the proposed method had some obvious merits, such as simple arithmetic, convenient operation, flexible and practical, fast and effective.

Practical implications

The application of a live example indicated that its evaluation effect was satisfactory.

Originality/value

The paper succeeds in solving a decision‐making problem for breeding target character shown as an interval number.

Details

Grey Systems: Theory and Application, vol. 1 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

Article
Publication date: 29 April 2021

Lei Gong, Zhiying Liu, Yanzhen Rong and Lihua Fu

The purpose of this study is to explore how inclusive leadership promotes organizational performance through ambidextrous innovation (i.e. exploratory and exploitative…

1014

Abstract

Purpose

The purpose of this study is to explore how inclusive leadership promotes organizational performance through ambidextrous innovation (i.e. exploratory and exploitative innovation). Moreover, the authors examine the moderating role of environmental uncertainty in the relationship between inclusive leadership and ambidextrous innovation.

Design/methodology/approach

This study conducted a questionnaire survey of high-tech enterprises in China and obtained 325 useable samples. The hypotheses were tested using latent path analysis and ordinary least squares regression.

Findings

The results indicate that exploratory and exploitative innovations mediate the relationship between inclusive leadership and organizational performance. Moreover, environmental uncertainty positively moderated the relationship between inclusive leadership and exploitative innovation.

Practical implications

Managers should value the critical role of inclusive leadership in promoting exploratory and exploitative innovation, which in turn improves organizational performance. Meanwhile, managers need to pay attention to the risk caused by environmental uncertainty.

Originality/value

This paper extends the influence of inclusive leadership on innovation from the individual level to the organizational level and reveals the influence mechanism of inclusive leadership on organizational performance. In addition, this study supplements the knowledge regarding the boundary conditions under which the influence of inclusive leadership is strengthened or weakened.

Details

Leadership & Organization Development Journal, vol. 42 no. 5
Type: Research Article
ISSN: 0143-7739

Keywords

Article
Publication date: 12 February 2019

Yijiao Ye, Yijing Lyu and Yanzhen He

The purpose of this study is to investigate the influence of servant leadership on hospitality employees’ proactive customer service performance (PCSP) by focusing on the…

2605

Abstract

Purpose

The purpose of this study is to investigate the influence of servant leadership on hospitality employees’ proactive customer service performance (PCSP) by focusing on the sequential mediating roles of harmonious passion and customer orientation and the moderating role of others’ approval of contingent self-esteem.

Design/methodology/approach

This study uses structural equation modeling with the four-wave data collected from eight Chinese hotels.

Findings

This study finds that servant leadership can promote hospitality employees’ PCSP by sequentially boosting their harmonious passion for work and customer orientation. Moreover, others’ approval of contingent self-esteem strengthens servant leadership’s effect on harmonious passion for work.

Originality/value

First, this study extends the servant leadership research by extending its outcome to hospitality employees’ PCSP. Second, this study enriches the understanding of the mediating mechanism between servant leadership and PCSP. Third, this study advances the research on servant leadership by identifying the moderating effect of employees’ others’ approval of contingent self-esteem between servant leadership and harmonious passion.

Details

International Journal of Contemporary Hospitality Management, vol. 31 no. 3
Type: Research Article
ISSN: 0959-6119

Keywords

Article
Publication date: 25 September 2018

Yanzhen Wang and Zhongwei Yin

This purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight…

Abstract

Purpose

This purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight polyethylene (UHMWPE) composites to develop a high-performance water-lubricated journal bearing material.

Design/methodology/approach

Tribological tests were conducted using a pin-on-disc tribometer using polished GCr15 steel pins against the UHMWPE composite discs under dry conditions with a contact pressure of 15 MPa and a sliding speed of 0.15 m/s. Scanning electron microscopy, laser 3D micro-imaging profile measurements and energy-dispersive X-ray spectrometry were used to analyze the morphologies and elemental distributions of the worn surfaces.

Findings

The results showed that hybrid CF and GF fillers effectively improved the wear resistance of the composites. The fiber fillers decreased the contact area, promoted transfer from the polymers and decreased the interlocking and plowing of material pairs, which contributed to the reduction of both the friction coefficient and the wear rate.

Originality/value

The UHMWPE composite containing 12.5 Wt.% CF and 12.5 Wt.% GF showed the best wear resistance of 2.61 × 10−5 mm3/(N·m) and the lower friction coefficient of 0.12 under heavy loading. In addition, the fillers changed the worn surface morphology and the wear mechanism of the composites.

Details

Industrial Lubrication and Tribology, vol. 71 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 11 April 2016

Yanzhen Wang, Zhongwei Yin, Dan Jiang, Gengyuan Gao and Xiuli Zhang

Water lubrication is significant for its environmental friendliness. Composite journal bearing is liable to deform for the huge pressure of water film. This paper aims to…

Abstract

Purpose

Water lubrication is significant for its environmental friendliness. Composite journal bearing is liable to deform for the huge pressure of water film. This paper aims to study the influence of elastic deformation on how lubrication functions in water-lubricated journal bearings and to provide references for designing composite journal bearings.

Design/methodology/approach

The combination of computational fluid dynamics and fluid-structure interaction is adopted in this paper to study the lubrication performance of water-lubricated compliant journal bearings. The influences of elasticity modulus and Poisson’s ratio on load-carrying capacity and elastic deformation are studied for different rotational speeds. Predictions in this work are compared with the published experimental results, and the present work agrees well with the experimental results.

Findings

A reference whether elastic deformation should be considered for composite journal bearings is proposed under different working conditions. Besides, a reference to determine water-lubricated plain journal bearings dimensions under different loads and rotational speeds is developed with the effect of both elastic deformation and cavitation being accounted.

Originality/value

The present research provides references as to whether elastic deformation should be considered in operation and to determine compliant journal bearings’ dimensions in the design process.

Details

Industrial Lubrication and Tribology, vol. 68 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 October 2019

Hulin Li, Zhongwei Yin and Yanzhen Wang

The purpose of this paper is to study the friction and wear properties of journal bearings under different working conditions.

Abstract

Purpose

The purpose of this paper is to study the friction and wear properties of journal bearings under different working conditions.

Design/methodology/approach

Friction coefficient and wear losses of journal bearing under different working conditions have been determined by a bearing test rig. The worn surfaces of bearing were examined by scanning electron microscopy and laser three-dimensional micro-imaging profile measurements, and the tribological behavior and wear mechanisms were investigated.

Findings

The wear loss and friction coefficient of bearing under starting-stopping working condition is far greater than that of steady-state working conditions. In addition, the maximum wear loss under start-up and stop conditions is about 120 times of that under stable operating conditions. Under stable working conditions, the main wear forms of bearings are abrasive wear, under starting-stopping working conditions the main wear mechanisms of bearings are adhesion wear, abrasive wear and fatigue wear.

Originality/value

These research results have certain practical value for understanding the tribology behavior of journal bearings under different working conditions.

Details

Industrial Lubrication and Tribology, vol. 72 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 6 December 2018

Zhen Yan, Dong Jiang, Xiaoming Gao, Can Zhang, Ming Hu, Dapeng Feng, Jiayi Sun, Lijun Weng and Chao Wang

This paper aims to study the tribological behavior of the WS2/oil-impregnated porous polyimide (PPI) solid/liquid composite system, in which both PFPE (perfluoropolyether…

Abstract

Purpose

This paper aims to study the tribological behavior of the WS2/oil-impregnated porous polyimide (PPI) solid/liquid composite system, in which both PFPE (perfluoropolyether) and SiCH (silahydrocarbons) oils with different hydrocarbon chains were used, respectively. Lubricating mechanism of the composite system was also explored.

Design/methodology/approach

The tribological behaviors of the WS2 films against the PPI cylindrical pins before and after immersing oil were evaluated under different loads by a reciprocating-type ball-on-disc tribometer.

Findings

The composite system exhibited the low and stable friction coefficient after the running-in stage, and the lubricant oil played a positive effect. It was found that the WS2/PFPE composite system exhibited more excellent lubricating property, although sole SiCH far exceeds PFPE in lubrication. The abnormal phenomenon mainly resulted from the influence of the oil amount. XRD results on the wear track surfaces indicated that PFPE and SiCH oils with different hydrocarbon chains were likely to preferentially adsorb to the edge plane and basal plane of the WS2 crystals, respectively.

Originality/value

In previous studies, liquid lubricants were directly dripped or spin-coated on the solid lubricant surface. Based on its potential advantage in application, the tribological behavior and mechanism of the solid lubricating film/oil-impregnated PPI composite system were investigated in this study.

Details

Industrial Lubrication and Tribology, vol. 71 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Content available
Article
Publication date: 8 June 2012

Yenming Zhang

741

Abstract

Details

Chinese Management Studies, vol. 6 no. 2
Type: Research Article
ISSN: 1750-614X

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