Shuaishuai Zhu, Baosen Zhang, Zhixin Ba, Xiangyang Mao, Weijie Fei and Zhangzhong Wang
This paper aims to investigate the friction and wear properties of Cr-Ni-Mo-V steel against 440C stainless steel under both water and water–silica mixture lubricant.
Abstract
Purpose
This paper aims to investigate the friction and wear properties of Cr-Ni-Mo-V steel against 440C stainless steel under both water and water–silica mixture lubricant.
Design/methodology/approach
The Cr-Ni-Mo-V steel specimens were taken from a forged steel brake disc with the process of quenching at 900°C and tempering at 600°C. The tribological testing was performed using a contact configuration of ball-on-flat with a liquid cell according to the ASTM standard. Detailed examinations on the worn surface were analyzed using a scanning electron microscope.
Findings
The results indicate that the friction coefficient and friction damage of the steel sliding under water–silica mixture are higher than those under water. The friction coefficient decreases with increasing load and increases with the sliding speed for the two lubricants. The mass wear rate presents a rising trend with both sliding load and speed. The wear mechanisms of the Cr-Ni-Mo-V steel sliding under the two lubricants are oxidation wear, abrasive wear and fatigue wear.
Research limitations/implications
Because of the chosen tribological testing approach, the research results could not describe the tribological performance of the brake disc accurately during actual braking process of the high-speed train. Therefore, researchers are encouraged to test the proposed propositions further.
Originality/value
This study shows that the tribology behavior of the Cr-Ni-Mo-V steel with water or water–silica mixture lubrications helps the industrial firms and academicians to work on the wear of the brake disc in rainwater or wet environment.
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This chapter examines how the breakthrough of Zhang Ziyi's depiction of a female kung fu master in The Grandmaster (2013) transforms the figure of the heroine in Chinese action…
Abstract
This chapter examines how the breakthrough of Zhang Ziyi's depiction of a female kung fu master in The Grandmaster (2013) transforms the figure of the heroine in Chinese action films. Zhang is well known for her acting in action films conducted by renowned directors, such as Ang Lee, Zhang Yimou and Wong Kar-wai. After winning 12 different Best Actress awards for her portrayal of Gong Ruomei in The Grandmaster, Zhang announced that she would no longer perform in any action films to show her highest respect for the superlative character Gong. Tracing Zhang's transformational portrait of a heroine in The Grandmaster alongside her other action roles, this analysis demonstrates how her performance projects the directors' distinctive gender viewpoints. I argue that Zhang's characterisation of Gong remodels heroine-hood in Chinese action films. Inheriting the typical plot of a daughter's use of martial arts for revenge for her father's death, Gong breaks from conventional Chinese action films that highlight romantic love during a woman's adventure and the decisive final battle scene. Beyond the propensity for sensory stimulation, Gong's characterisation enables Zhang to determine that women can really act in action films – demonstrating their inner power and ability to create multi-layered characters – not merely relying upon physical action. This chapter offers a relational perspective of how women transform the action film genre not merely as gender spectacles but as embodied figures that represent emerging female subjectivity.
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China has a bad reputation — justified or not — for corruption: in a recent Transparency International survey, it was listed by US and European businesspeople as one of the three…
Abstract
China has a bad reputation — justified or not — for corruption: in a recent Transparency International survey, it was listed by US and European businesspeople as one of the three most corrupt countries in Asia, though its ranking fell slightly in 1996. A national survey revealed that ordinary Chinese regard corruption as the most serious problem after inflation, though 52 per cent expressed doubt that the Government could do anything about it. In 1995, in Beijing alone, 1,085 cases of corruption were uncovered. In 1996, in the Working Report of the Supreme Peoples's Procuratorate, the Chief Procurator Zhang Siqing observed:
Ruijuan Wu, Yixiao Hu and Peiyu Li
The objective of this study is to examine the effects of pictures (consumer pictures vs. product pictures vs. no pictures) in online consumer reviews on product evaluation and to…
Abstract
Purpose
The objective of this study is to examine the effects of pictures (consumer pictures vs. product pictures vs. no pictures) in online consumer reviews on product evaluation and to determine the mechanism and boundary conditions behind such effects.
Design/methodology/approach
The research consisted of three laboratory experiments.
Findings
The results showed that consumer pictures led to the most favorable product evaluation. Study 1 showed that persuasive effect was the mechanism behind the main effect. Study 2 showed that for problem-solving products, consumer pictures increased product evaluation significantly; for enhancing products, there was no significant difference of product evaluation among consumer pictures, product pictures and no picture. The results of Study 3 showed that for the unfamiliar brand, consumer pictures significantly enhanced product evaluation; for the highly familiar brand, there was no significant difference among consumer pictures, product pictures and no picture. The present research used persuasive effects to examine the mechanism behind the interaction effects.
Practical implications
The study provides managerial implications for online store owners about how to manage pictures in online reviews.
Originality/value
This study supplements the literature on online consumer reviews and enriches the study of effects of pictures.
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Xiaomeng Zhang, Sang Xiong, Feng Gao, Jinyuan Du and Qin-Jian Du
WO3 particles were prepared by the sol-gel method. Tetraethyl silicate (TEOS) was used to obtain a SiO2-coated WO3 nanoparticle. Quantum chemical parameters of oleic acid…
Abstract
Purpose
WO3 particles were prepared by the sol-gel method. Tetraethyl silicate (TEOS) was used to obtain a SiO2-coated WO3 nanoparticle. Quantum chemical parameters of oleic acid, triethanolamine, glycerol and methyl pentane as dispersants were theoretically calculated. Tribological properties of SiO2/WO3 nanocomposite lubricant were carried out on an MRS-10A four-ball friction and wear tester.
Design/methodology/approach
The purpose of this study is to investigate the preparation and tribological properties of SiO2/WO3 nanocomposite lubricant.
Findings
The obtained SiO2-coated WO3 nanoparticle (nano-SiO2/WO3) with a particle size of about 70 nm. The calculated adsorption energy of triethanolamine on the surface of the steel ball is 554.6 eV, and triethanolamine is selected as the dispersant. The dispersion effect of SiO2/WO3 nanocomposite lubricant is good, which shows that triethanolamine oleate plays a good dispersion role in the preparation of lubricant, which is consistent with the calculation results of the adsorption capacity of dispersant. As a good auxiliary lubricant, SiO2 can improve the tribological properties and wear resistance of WO3.
Originality/value
Nanocomposite lubricants have been the focus of research in recent years, which could greatly reduce energy consumption. And the SiO2/WO3 exhibited excellent lubrication performance as a lubricant additive. The lubrication mechanism of SiO2/WO3 nanocomposite lubricant is the synergistic lubrication mechanism of friction film lubrication and antifriction bearing. This study could provide a certain reference for the practical application of nanocomposite lubricants.