Yingxiang Zhao, Junde Guo, Xiaoni Yan, Shan Du, Min Gong, Biao Sun, Junwen Shi and Wen Deng
The purpose of this paper is to investigate the friction and wear mechanisms in copper-based self-lubricating composites with MoS2 as the lubricating phase, which provides a…
Abstract
Purpose
The purpose of this paper is to investigate the friction and wear mechanisms in copper-based self-lubricating composites with MoS2 as the lubricating phase, which provides a theoretical basis for subsequent research on high-performance copper-based self-lubricating materials.
Design/methodology/approach
Friction tests were performed at a speed of 100 r/min, a load of 10 N, a friction radius of 5 mm and a sliding speed of 30 min. Friction experiments were carried out at RT-500°C. The phase composition of the samples was characterized by X-ray diffraction of Cu Ka radiation, and the microstructure, morphology and elemental distribution were characterized by scanning electron microscopy and energy dispersive spectroscopy. Reactants and valences formed during the wear process were analyzed by X-ray photoelectron spectroscopy.
Findings
The addition of MoS2 can effectively improve friction-reducing and anti-wear action of the matrix, which is beneficial to form a lubricating film on the sliding track. After analyzing different changing mechanism of the sliding tracks, the oxides and sulfides of MoS2, MoO2, Cu2O, CuO and Ni(OH)2 were detected to form a synergetic lubricating film on the sliding track, which is responsible for the excellent tribological properties from room to elevated temperature.
Research limitations/implications
For self-lubrication Cu–Sn–Ni–MoS2 material in engineering field, there are still few available references on high-temperature application.
Practical implications
This paper provides a theoretical basis for the following research on copper-based self-lubricating materials with high performance.
Originality/value
With this statement, the authors hereby certify that the manuscript is the results of their own effort and ability. They have indicated all quotes, citations and references. Furthermore, the authors have not submitted any essay, paper or thesis with similar content elsewhere. No conflict of interest exits in the submission of this manuscript.
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This paper aims to propose the mechanism of cross-network effect embedded, which can help cross-border e-commerce (CBEC) platforms strengthen cooperative relationships with…
Abstract
Purpose
This paper aims to propose the mechanism of cross-network effect embedded, which can help cross-border e-commerce (CBEC) platforms strengthen cooperative relationships with sellers more equitably and effectively by using the network structural characteristics of the platforms themselves.
Design/methodology/approach
A two-stage evolutionary game model has been used to confirm the influence factors. The mathematical derivation of evolutionary game analysis is combined with the simulation method to examine the role of cross-network effect in cooperation. The evolutionary game model based on the cross-network effect is proposed to achieve better adaptability to the study of cooperation strategy from the two-sided market perspective.
Findings
The evolutionary game model captures the interactions of cross-network effect and the influence factors from a dynamic perspective. The cross-network effect has a certain substitution on the revenue-sharing rate of SMEs. CBEC platforms can enhance the connection between consumers and the website by improving the level of construction, which is a good way to attract sellers more cost-effectively and efficiently.
Research limitations/implications
This study provides a new method for the validation of the cross-network effect, especially when data collection is difficult. But this method is only a numerical simulation. So the conclusions still need to be further tested empirically. Besides, researchers are advised to explore the relationship between the added user scale and the cross-network effect in some specificCBEC platforms.
Practical implications
This study provides a new method for the validation of the cross-network effect, especially when data collection is difficult. But this method is only a numerical simulation. So the conclusions still need to be further tested empirically. Besides, researchers are advised to explore the relationship between the added user scale and the cross-network effect in some specific CBEC platforms.
Originality/value
Investigations that study cooperation strategy from the cross-network effect perspective in CBEC are limited. The research figured out which influence factors are affected by the cross-network effect in cooperation. A two-stage evolutionary game model was proposed to explain the interaction of the factors. The evolutionary game analysis with a simulation method was combined to highlight the role of cross-network effect on cooperation strategy to give a deeper investigation into the sustainable cooperation ofCBEC.
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Jian Wang, Xinyi Zhang, Min Du, Xueyan Shan and Zhiyu Tian
The purpose of this study is to provide ideas and theoretical guidance for green, environmentally friendly and efficient “bacteriostasis with bacteria” technology.
Abstract
Purpose
The purpose of this study is to provide ideas and theoretical guidance for green, environmentally friendly and efficient “bacteriostasis with bacteria” technology.
Design/methodology/approach
In this paper, a beneficial strain of bacteria was extracted and purified from marine mud. Weight-loss test, morphological observation and electrochemical test were used to systematically study the effect of sulfate-reducing bacteria (SRB)-induced corrosion inhibition on X65 steel in simulated offshore oil field production water.
Findings
The results showed that a beneficial strain was selected and identified as Vibrio alginolyticus. Under the condition of co-culture of SRB, the average corrosion rate of X65 steel was significantly reduced. In the mixed bacterial system, the surface of X65 steel samples was relatively flat, and the structure of biofilm and corrosion product film was dense. The number of corrosion pits, the average diameter and depth of corrosion pits were significantly reduced. The localized corrosion of X65 steel was significantly inhibited.
Originality/value
The complex and changing marine environment makes the corrosion problem of marine steel increasingly severe, and the microbiologically influenced corrosion (MIC) caused by SRB is particularly serious. The research and development of environmentally friendly corrosion protection technology is a long-term and difficult problem. The use of beneficial microorganisms to control MIC is a green and efficient anticorrosion measure. Compared with terrestrial microorganisms, marine microorganisms can adapt to complex environments, and their metabolites exhibit special biological activities. The use of marine beneficial bacteria can inhibit SRB activity to achieve the corrosion inhibition effect.
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This study aims to examine the effects of dialect connectedness between the chairman and the chief executive officer (CEO) (DCCC) on the tunneling activities of controlling…
Abstract
Purpose
This study aims to examine the effects of dialect connectedness between the chairman and the chief executive officer (CEO) (DCCC) on the tunneling activities of controlling shareholders.
Design/methodology/approach
This study uses abnormal related-party transactions (ARPT) as a proxy for tunneling activities and traces dialects of chairmen and CEOs based on the respective birthplace information. Baseline results are examined using a fixed-effects model. The results remain robust when using the instrumental variable approach, propensity score matching (PSM) technique, changing the measurement of tunneling and Heckman two-step selection model.
Findings
The results show that DCCC reduces tunneling activities. This negative association is more pronounced for non-state-owned enterprises and firms whose chairmen and CEOs work in the respective hometowns. DCCC restrains tunneling activities through mechanisms by establishing an informal supervisory effect on CEOs because the CEOs fear reputational damage and strengthening cooperation between chairmen and CEOs. Further analyses suggest that this negative association is more significant when chairmen and CEOs are non-controlling shareholders, but the association is weakened during the coronavirus disease 2019 (COVID-19) crisis.
Originality/value
As dialect is a carrier of culture, this study's results imply that cultural proximity can replace formal mechanisms to enhance corporate governance.
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Zhi Guo, Zhongde Shan, Feng Liu, Dong Du and Mengmeng Zhao
In this paper, the effects of the adhesive and curing agent contents on the tensile strength, bending strength, gas evolution and gas permeability of three-dimensional printed…
Abstract
Purpose
In this paper, the effects of the adhesive and curing agent contents on the tensile strength, bending strength, gas evolution and gas permeability of three-dimensional printed sand molds are studied. A strength model of the three-dimensional printed sand molds is proposed. The multi-material composite sand mold forming test is carried out. In addition, the mesostructure of the sand mold is studied.
Design/methodology/approach
The performances of three-dimensional printed sand mold such as tensile strength, bending strength, gas evolution and gas permeability are studied using the standard test methods. The mesostructure of the sand mold is studied by digital core technology.
Findings
A sand mold strength model based on the resin adhesive content, curing agent content and sand mold compactness are obtained. Two types of multi-material composite three-dimensional printed sand molds are proposed. An increase in the curing agent content in the sand mold widens the mesoscopic characteristic size distribution of the sand mold, and large-sized mesostructures appear, resulting in a decrease in the sand mold bearing capacity.
Practical implications
Process parameters that affect the performance of three-dimensional printed sand mold are revealed. The sand mold bearing curve provides a reference for the ultimate design of three-dimensional printed sand mold.
Originality/value
The paper deals with experimental work on the performance and mesostructure of multi-material composite three-dimensional printed sand mold with different contents of adhesive and curing agent. That gives a perspective on future designs of sand mold based on these principles.
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Yahiaoui Zidan, Sherazede Bouderbala, Cherrad Hayet and Bouchenak Malika
The purpose of this study is to determine the effect of olive cake (OC) on lipid peroxidation as well as antioxidant enzymes activities of serum, red blood cells (RBCs) and liver…
Abstract
Purpose
The purpose of this study is to determine the effect of olive cake (OC) on lipid peroxidation as well as antioxidant enzymes activities of serum, red blood cells (RBCs) and liver, in streptozotocin (STZ)-induced-diabetic rat fed cholesterol-enriched diet.
Design/methodology/approach
Hypercholesterolemic male rats were rendered diabetic (HC-D) by a single intraperitoneal injection dose of STZ (35 mg/kg BW). HC-D rats were divided into two groups fed for 28d a diet supplemented with OC at 7.5 percent (HC-D-OC) or not (HC-D). A control group (C) was submitted to standard diet containing 20 per cent casein for the same experimental period.
Findings
RBCs, serum and liver thiobarbituric acid reactive substances (TBARS) contents were significantly increased in HC-D, compared to C group (p = 0.04, p = 0.02 and 0.03). These values were significantly decreased (48 per cent and 64 per cent; p = 0.02 and p = 0.0007) in serum and liver of HC-D-OC vs HC-D group. In RBCs, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) activities were, respectively, 1.5, 2- and 1.7-fold higher (p = 0.03, p = 0.008 and p = 0.03) in HC-D group compared to HC group. In serum and liver, SOD, CAT and GST activities were, respectively, 1.3-, 2.6- and 1.6-fold increased (p = 0.03, p = 0.007 and p = 0.02). In HC-D-OC compared to HC-D group, RBCs glutathione peroxidase (GSH-Px), CAT and GST activities were, respectively, 2.1-, 3.3- and 2.1-fold higher (p = 0.04, p = 0.0009 and p = 0.03). In serum, SOD and CAT activities were, respectively, 1.5- and 1.9-fold increased (p = 0.02, p = 0.02). In liver, SOD, GSH-PX, CAT and GST activities were significantly increased (p = 0.005, p = 0.03, p = 0.02 and p = 0.04).
Originality/value
In diabetic rats-fed cholesterol-enriched diet, OC was able to reduce oxidative stress by decreasing lipid peroxidation and increasing antioxidant enzymes activities in serum, RBCs and liver.
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Xiaoxiao Shi, Wei Shan, Zhaohua Du, Richard David Evans and Qingpu Zhang
Although online reviews have become a key source of information for consumer purchasing decisions, little is known about how the concreteness of language used in these reviews…
Abstract
Purpose
Although online reviews have become a key source of information for consumer purchasing decisions, little is known about how the concreteness of language used in these reviews influences perceptions of deception. This study aims to address this important gap by drawing on psycholinguistic research and Language Expectancy Theory to examine how and when the concreteness of online reviews (abstract vs concrete) impacts consumers’ perceived deception.
Design/methodology/approach
Two scenario-based experiments were conducted to examine how the concreteness of online reviews (abstract vs concrete) influences consumers’ perceptions of deception, considering the mediating role of psychological distance to online reviews and the moderating effects of Machiavellianism (Mach) and reviewer identity disclosure.
Findings
Online reviews that include concrete language lead to lower perceived deception by reducing consumers’ psychological distance from the review. For consumers with higher levels of Mach, online reviews written in abstract (vs concrete) language result in higher perceived deception via psychological distance, while for consumers with lower Mach, online reviews written in concrete (vs abstract) language result in higher perceived deception via psychological distance.
Research limitations/implications
To the best of the authors’ knowledge, this study is one of the first to highlight the relevance of linguistic style (i.e. concrete review vs abstract review) on consumers’ perceived deception toward online reviews in the context of e-commerce.
Practical implications
The framework enables managers of online retailing platforms to identify the most effective strategies to decrease consumers’ perceived deception via the appropriate utilize of linguistic styles of online reviews.
Originality/value
This study contributes to both theory and practice by deepening knowledge of how and when the concreteness of online reviews (abstract vs concrete) affects consumers’ perceived deception and by helping managers of online retailing platforms make the most effective\ strategies for reducing consumers’ perceived deception toward online reviews during online shopping.
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Zhi Guo, Zhongde Shan, Dong Du, Mengmeng Zhao and Milan Zhang
This paper aims to determine how the viscosity and curing agent content affect the flowability of moist silica sand granules. In addition, a coating device was designed according…
Abstract
Purpose
This paper aims to determine how the viscosity and curing agent content affect the flowability of moist silica sand granules. In addition, a coating device was designed according to the flow properties of silica sand granules.
Design/methodology/approach
The flowability of silica sand granules premixed with two curing agents of different viscosities is studied using a Jenike shear apparatus. An open-ended device was used in discharge testing of sand granules with a design based on the variable dip angle of the two plates and variable outlet size.
Findings
The test results show that increasing the curing agent content would significantly decrease the flowability of silica sand granules, and a curing agent of higher viscosity has a greater effect on the flowability of silica sand. The presence of a curing agent strengthens the cohesion among sand granules, lubricates them and restrains their deformation. The shape function of the coating device was obtained by theoretical derivation.
Practical implications
The flow properties provide a valuable theoretical guidance for the design of coating device for sand mold printing.
Originality/value
This paper deals with experimental work on flow properties of silica sand granules with different viscosities and curing agent content. The shape function of a wedge-shaped coating device is obtained based on experimental data.
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Dalei Zhang, Xinwei Zhang, Enze Wei, Xiaohui Dou and Zonghao He
This study aims to improve the corrosion resistance of TA2-welded joints by superhydrophobic surface modification using micro-arc oxidation technology and low surface energy…
Abstract
Purpose
This study aims to improve the corrosion resistance of TA2-welded joints by superhydrophobic surface modification using micro-arc oxidation technology and low surface energy substance modification.
Design/methodology/approach
The microstructure and chemical state of the superhydrophobic film layer were analyzed using scanning electron microscopy, energy dispersive X-ray spectroscopy, three-dimensional morphology, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared absorption spectroscopy. The influence of the superhydrophobic film layer on the corrosion resistance of TA2-welded joints was investigated using classical electrochemical testing methods.
Findings
The characterization results showed that the super hydrophobic TiO2 ceramic membrane was successfully constructed on the surface of the TA2-welded joint, and the construction of the super hydrophobic film greatly improved the corrosion resistance of the TA2-welded joint.
Originality/value
The superhydrophobic TiO2 ceramic membrane has excellent corrosion resistance. The micro nanostructure in the superhydrophobic film can intercept air to form an air layer to prevent the corrosion medium from contacting the surface, thus, improving the corrosion resistance of the sample.
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Chengcheng Liao, Xin Wen, Shan Li and Peiyuan Du
Companies increasingly leverage artificial intelligence (AI) to enhance human performance, particularly in e-commerce. However, the effectiveness of AI augmentation remains…
Abstract
Purpose
Companies increasingly leverage artificial intelligence (AI) to enhance human performance, particularly in e-commerce. However, the effectiveness of AI augmentation remains controversial. This study investigates whether, how and why AI enhances human agents’ sales through a randomized field experiment.
Design/methodology/approach
This study conducts a two-by-two factorial randomized field experiment (N = 1,090) to investigate the effects of AI augmentation on sales. The experiment compares sales outcomes handled solely by human agents with those augmented by AI, while also examining the moderating effect of agents’ experience levels and the underlying mechanisms behind agents’ responses.
Findings
The results reveal that AI augmentation leads to a significant 5.46% increase in sales. Notably, the impact of AI augmentation varies based on agents’ experience levels, with inexperienced agents benefiting nearly six times more than their experienced counterparts. Mediation analysis shows that AI augmentation improves response timeliness, accuracy and sentiment, thereby boosting sales.
Originality/value
This study highlights the role of AI augmentation in human–AI collaboration, demonstrates the varying impacts of AI augmentation based on agents’ experience levels and offers insights for organizations on how to regulate AI augmentation to enhance agent responses and drive sales.