Zhenbo Zhang, Yuxuan Zhang and Mengfan Yan
This paper aims to explore the impact of product market competition (PMC) on companies’ investment in external auditing.
Abstract
Purpose
This paper aims to explore the impact of product market competition (PMC) on companies’ investment in external auditing.
Design/methodology/approach
This paper applies a conceptual framework derived from demand–supply analysis and a panel data set of 2,263 listed manufacturing companies in China covering the period 2012–2019. In the assessment of PMC, this study measures industry-level competition intensity and company-specific market power separately.
Findings
Industries appear to engage in a lower average level of external auditing if industrial competition intensity is either too high or too low. Similarly, companies spend less on external auditing if their market power is either too strong or too weak, and the company-level inverted U-shaped relationship is much more evident in industries with weak PMC.
Originality/value
This paper shows that a company’s external audit strategy is affected by the level of competition it faces in its market. The findings of this paper can improve the current linear PMC–auditing theoretical framework and provide insights into the strategic auditing of listed companies in China. The findings also have significant implications for policy recommendations regarding corporate governance and market scrutiny regulations.
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Chenxiang Qian, Chih-Fu Wu, Zhenbo Zhang and Hsin-Yu Huang
The purpose of this paper is to explore current marketing communication mixes (MCMs) in two industries, electronics home appliance stores (face-to-face interaction) and remote…
Abstract
Purpose
The purpose of this paper is to explore current marketing communication mixes (MCMs) in two industries, electronics home appliance stores (face-to-face interaction) and remote care (interface-mediated interaction), to propose marketing strategies from the perspective of service design and determine the relationships between service interaction patterns and MCMs in the pre-service phase.
Design/methodology/approach
Six industry experts in marketing were interviewed through semi-structured interviews, the topic of which focused on the details of five MCMs and their correlations were analyzed using a customer journey maps. Finally, the MCMs were further explored to verify differences in attractiveness to customers, respectively.
Findings
The result showed that the most attractive activity for the electronics home appliance stores customer is the promotion. And the four face-to-face service interaction patterns and MCMs exhibited a low correlation. In addition, the customers of remote care service argued that the personnel selling was the most attractive MCMs to them. For customers who utilize smart devices to communicate with advertisement exhibited the highest correlation coefficient.
Research limitations/implications
The limitation of this study is that the research only conducts interview research on two service industries.
Practical implications
This study was expected to develop improved marketing communication strategies to remedy the sales predicament induced by virtual channels and to increase people’s acceptance of remote care service.
Originality/value
The value of this paper is to analyze the correlation and difference of MCMs and service interaction patterns between electronics home appliance stores and remote care, and propose a structural model of MCMs for two different industries.
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Zhong Wu, Qing Hu, Zhenbo Qin, Yiwen Zhang, Da-Hai Xia and Wenbin Hu
Nickel-aluminum bronze (NAB) has been widely used in ship propellers. It is always subjected to local micro-plastic deformation in service environments. This paper aims to study…
Abstract
Purpose
Nickel-aluminum bronze (NAB) has been widely used in ship propellers. It is always subjected to local micro-plastic deformation in service environments. This paper aims to study the influence of plastic deformation on the mechanical strength and corrosion resistance of NAB in 3.5 Wt.% NaCl solution.
Design/methodology/approach
Scanning electron microscope and X-ray diffraction were used to analyze the microstructure of NAB alloy with different plastic deformations. Mechanical properties of the sample were measured by tensile experiment, and corrosion behavior was studied by electrochemical measurements and the long-term immersion corrosion test.
Findings
Results showed that the plastic deformation caused lattice distortion but did not change the microstructure of NAB alloy. Microhardness and yield strength of NAB were significantly improved with the increase of deformation. The lattice distortion accelerated the formation of corrosion product film, which made the deformed alloy show a more positive open-circuit potential and an increased Rp. However, during the long-term immersion corrosion, the corrosion resistance of NAB alloys deteriorated with the increase of plastic deformation. This is because larger plastic deformation brought about higher internal stress in corrosion product film, which resulted in the premature peeling of the film and the loss of its protective effect on the alloy substrate.
Originality/value
Tensile plastic deformations were found to cause a decline in the corrosion resistance of NAB. And the mechanism was clarified from the evolution of corrosion products during the corrosion process.
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Zhenbo Qin, Xuehan Li, Da-Hai Xia, Yiwen Zhang, Zhong Wu and Wenbin Hu
The purpose of this paper is to clarify the effect of compressive stress on cavitation-erosion corrosion behavior of 304 stainless steel.
Abstract
Purpose
The purpose of this paper is to clarify the effect of compressive stress on cavitation-erosion corrosion behavior of 304 stainless steel.
Design/methodology/approach
Compressive stresses of 60 MPa and 120 MPa were applied to 304 stainless steel through a self-designed loading device, and cavitation erosion-corrosion tests were performed using an ultrasonically vibratory apparatus. Scanning electron microscope and X-ray diffraction were used to analyze the microstructure evolution, and corrosion behavior was studied by electrochemical analysis.
Findings
The cavitation weight loss of 304 stainless steel decreased with the compressive stress. After cavitation corroded for 8 h, the weight loss for the specimen with 120 MPa compressive stress was 5.11 mg/cm2, which was reduced by 56.7% from that of the specimen without loading stress (11.79 mg/cm2). The reason can be attributed to that compressive stress promoted the deformation-induced martensitic transformation during the cavitation process, which could not only provide a cushioning effect by absorbing cavitation impact energy but also improve the hardness of 304 stainless steel.
Originality/value
Compressive stress was found to restrain the cavitation damage on 304 stainless steel, and the corresponding mechanism was proposed.
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Qiang Li, Yujun Wang, Shuo Zhang, Wei-Wei Xu, Lu Bai and Zhenbo Wang
Surface textures have been widely used in thrust bearings as a means of enhancing the tribological performance. The effect of textures with a spiral distribution on the…
Abstract
Purpose
Surface textures have been widely used in thrust bearings as a means of enhancing the tribological performance. The effect of textures with a spiral distribution on the lubrication characteristics of thrust bearings has not been fully covered. This paper aims to investigate and find the optimal structure and distribution parameters of textures with the maximum loading capacity and minimum friction force as goals.
Design/methodology/approach
Combining the multi-objective optimization method based on the non-dominated sorted genetic algorithm-II with response surface methodology, the key textured parameters are optimized. Local sensitivity analysis is used to evaluate the impact level of each parameter.
Findings
Spiral distribution of textures can effectively improve the lubrication performance of the thrust bearing compared with the linear distribution. The distribution with high amplitudes and high cycle numbers will weaken the spiral effect and destroy the high-pressure region. Through the multi-objective optimization of the textured structure and distribution parameters, the loading capacity demonstrates a 55.05per cent improvement compared to the basic model. Textured width is the most sensitive parameter for both loading capacity and friction force.
Originality/value
Present research provides a fundamental design guide for textured thrust bearings.
Details
Keywords
Qiang Li, Shuo Zhang, Yujun Wang, Wei-Wei Xu, Zengli Wang and Zhenbo Wang
Shear stresses have a considerable influence on the characteristics of lubricants and become significant at high rotating speeds. This study aims to investigate the influences of…
Abstract
Purpose
Shear stresses have a considerable influence on the characteristics of lubricants and become significant at high rotating speeds. This study aims to investigate the influences of shear cavitation (SC) on loading capacity of journal bearings.
Design/methodology/approach
A principal normal stress cavitation criterion based on the stress applied to flowing lubricant in journal bearings is developed and used to investigate SC in journal bearings. A computational fluid dynamic (CFD) model for calculating the loading capacity is established using this criterion. After validation with experimental results, the loading capacity is calculated under different conditions.
Findings
The calculation results indicate that SC intensifies when viscosity, speed and eccentricity increase. Angle of loading capacity with SC is larger than that without SC. The magnitude of loading capacity with SC is smaller than that without SC due to the decrease in the ultimate pressure. In addition, the magnitude difference between the loading capacity with and without SC increases when viscosity, speed and eccentricity increases.
Originality/value
Present research can provide some guidance for calculating the loading capacity when a journal bearing is operating at high speed or with a high viscosity lubricant.
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Yujun Wang, Qiang Li, Shuo Zhang, Xinhao Tang, Weiwei Xu and Zhenbo Wang
The loading mechanism of textures considering turbulence has not been fully covered. This paper aims to investigate the effect of turbulence on the textured loading capacity under…
Abstract
Purpose
The loading mechanism of textures considering turbulence has not been fully covered. This paper aims to investigate the effect of turbulence on the textured loading capacity under water lubrication and to analyze the causes of the turbulence effect.
Design/methodology/approach
Computational fluid dynamic models with different textured shapes are established after validation. The transition shear stress transport (SST) model, which is suitable for predicting the transition process of fluid from laminar state to turbulent state, is adopted in the present study. To illustrate the effect of turbulence, the loading capacity of textures predicted by transition SST model and laminar model is compared.
Findings
The loading capacity is higher after considering turbulence because more lubricant enters into textures and the flow rate of lubricant to textured outlet increases. There exists an optimal textured depth ratio and density for loading capacity and the change of flow state would not affect the optimal values. The degree of fluid blockage at textured outlet has a dominant influence on loading capacity. As the textured shape changes to triangle or ellipse from rectangle, the vortices at the textured bottom move forward and the blockage at a textured outlet is enhanced, which makes loading capacity improved under the action of blocking effect.
Originality/value
The enhancement of the blocking effect is found to be crucial to the improvement of textured loading capacity after considering turbulence. Present research provides references to understand the loading mechanism of textures under turbulent conditions.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0149/
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Qiang Li, Yujun Wang, Shuo Zhang, Wei-Wei Xu, Zengli Wang and Zhenbo Wang
Surface texturing has been proven as an effective means of contact performance enhancement. However, limited work has been done to investigate the regular relationship to solve…
Abstract
Purpose
Surface texturing has been proven as an effective means of contact performance enhancement. However, limited work has been done to investigate the regular relationship to solve the multi-parameters problem of textures, and inertia effect and elastic deformation were seldom considered together in previous optimization work. This paper aims to quantitatively obtain the relationship between the textured depth and liquid film thickness and find the effect of deformation on the optimal textured height ratio in elastic parallel sliders.
Design/methodology/approach
Numerical models of hydrodynamic lubrication are established based on the computational fluid dynamic method. Elastic deformation is considered through fluid–structure interaction (FSI) method. Using response surface optimization method, textured parallel sliders are optimized with maximum loading capacity as the objective.
Findings
The results show that the optimal height ratios are all within the range of 0.60-0.65 when textured parallel sliders are considered as rigid. After considering the effect of elastic deformation, loading capacity drops and is reduced more obviously with a decrease in the elastic moduli. The optimal height ratios are within the range of 0.60-0.63, which shows that FSI has a considerable influence on loading capacity but has no significant influence on the optimal height ratio.
Originality/value
The present research provides a theoretical reference for engineering application of elastic textured parallel sliders.
Details
Keywords
Qiang Li, Shuo Zhang, Yujun Wang, Wei-Wei Xu and Zhenbo Wang
The growing demand of efficiency and economy has led to a dramatic increase of the operating speed of the journal bearing, with a higher temperature distribution. This paper aims…
Abstract
Purpose
The growing demand of efficiency and economy has led to a dramatic increase of the operating speed of the journal bearing, with a higher temperature distribution. This paper aims to investigate the three-dimensional temperature distribution of journal bearings.
Design/methodology/approach
A thermo-hydrodynamic lubrication model of a journal bearing was established based on the full 3D CFD method. A two-sided wall was used to include the conjugate heat transfer effect. The temperature-dependent characteristics of lubrication and cavitation impact were also included. The simulation results well agreed with the experimental results. Based on this method, the three-dimensional temperature distribution was analyzed under different operating conditions.
Findings
The temperature distribution in the radial direction had a difference. An increase of speed and de-crease of inlet temperature promoted temperature differences in the higher temperature zone and the increasing temperature zone, respectively. However, the inlet pressure had less influence on these differences. The temperature distribution was basically the same at a lower bearing conductivity. As the conductivity increased, the radial temperature difference was increased.
Originality/value
The temperature distribution in the radial direction was found under different operating conditions, and the present research provides references to understand the three-dimensional temperature distribution of journal bearings.
Details
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Zhenbo Qin, Jiale Li, Yiwen Zhang, Zhong Wu and Wenbin Hu
The purpose of this paper is to improve the corrosion resistance of stainless-steel bipolar plate by magnetron sputtering.
Abstract
Purpose
The purpose of this paper is to improve the corrosion resistance of stainless-steel bipolar plate by magnetron sputtering.
Design/methodology/approach
TiC/amorphous carbon composite film was deposited by magnetron sputter at four different temperature of 25°C, 200°C, 300°C and 400°C. The morphology, composition and structure of the film were characterized by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. And its corrosion behavior was analyzed through electrochemical impedance spectroscopy, potentiodynamic and potentiostatic polarization tests.
Findings
A compact TiC/amorphous carbon film was prepared by magnetron sputtering on 316L stainless steel, and the particles of the film were refined with the increase in sputtering temperature. High temperature promoted the formation of TiC and C–C sp2 hybrid carbon, but excessively high temperature caused the oxidation of Ti and a significant decrease in sp2 hybrid carbon. The corrosion resistance of the film increased with the temperature, and the corrosion current density polarization at 0.86 V and 1.8 V for TiC/a–C film prepared at 400 °C is only 1.2% and 43.2% of stainless steel, respectively.
Originality/value
The corrosion resistance of amorphous carbon films was improved by the doping of Ti carbide, and the appropriate sputtering temperature was obtained.