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The purpose objective of this study is to identify the friction coefficient and friction effect in electromagnetic upsetting (EMU) high-speed forming process.

Based on numerical simulation and upsetting experiment of 2A10 aluminum alloy bar, the friction coefficient between contact surfaces is obtained by combining the fitting displacement distribution function and the electromagnetic-mechanical coupling numerical model, and the influence of friction effect is analyzed.

The maximum impact velocity and acceleration during EMU are 13.9 m/s and −3.3 × 106 m/s², respectively, and the maximum strain rate is 7700 s⁻¹. The functional distribution relationship between friction coefficient combination (FS, FD) and characteristic parameters [upper diameter (D1) and middle diameter (D2)] is established. The values of FS and FD are 0.1402 and 0.0931, respectively, and the maximum relative error is 2.39%. By analyzing the distribution of equivalent stress and strain, it is found that plastic deformation has obvious zoning characteristics and there is serious failure concentration in the strong shear zone.

Friction coefficient significantly affects stress or strain distributions in material forming process, but it is difficult to obtain friction coefficients through experimental tests in the high-speed forming process. In this paper, a multi-field coupling numerical model is proposed to determine friction coefficients and applied to the electromagnetic impact loading process (a high-speed forming process).

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0154/

Under the de-capacity circumstances of coal production in China, the purpose of this paper is to examine the processes underlying the association between job insecurity (JI) and miners’ safety performance, proposing that resource consumption is a prominent theoretical explanation for this association. By developing a mediation model, the authors examined the mediating role of emotional exhaustion (EE) between JI and miners’ safety performance.

Through the time-lagged survey method, the authors collected 349 samples from three coal mines in Shanxi Lu’an Group, the hypotheses were tested through confirmatory factor analysis, structural equation model analysis and bootstrapping in AMOS software.

Results shed light on that JI negatively predicts the safety performance subfactors, including safety compliance (SC) and safety participation (SP). EE plays a partial mediating role between JI and safety performance. In particular, the finding indicated that JI exerts a more significant impact on SP than SC, revealing that JI produces a more significant adverse effect on miners’ conscious safety behaviors than skill-based safety behaviors.

This study contributes to display the influence path of JI as a stressor on miners’ safety performance in the coal mine rather than a stimulus. The mediation model results not only help us understand the association between JI and safety performance but also provide a feasible way to mitigate the negative effects of JI.

The purpose of this paper is to assess the serious corrosion problems of the water injection system on the offshore oil field and to study the type, and effect factors and mechanisms of corrosion on the offshore oil field in order to develop an effective corrosion inhibitor for the sea water injection system.

The corrosion of metal in a water injection system was studied by weight‐loss and electrochemical methods.The effect factors and mechanisms of corrosion on the offshore oil field were proposed from the trend of corrosion.

FeCO₃ is the main corrosion product in the water injection system of the Chengdao Offshore Oil Field. The corrosion rate of coupons in sea water injection systems reaches a maximum peak at a temperature of 50‐60°C. The corrosion rate of coupons exposed in all three water samples increased with an increase in the dissolved oxygen concentration. When the mixed ratio of sea water and produced water and well water is 1:3:1 or 1:2:2, the corrosion rate of carbon steel is lower than is the case in pure water. The electrochemical mechanism of corrosion indicates that corrosion in the well water, produced water, and sea water samples were all controlled by the oxygen absorption process, which controlled the cathodic reaction. The corrosion rate of coupons followed the ranking order: well water; produced water; sea water.

This paper provides the main corrosion product in the water injection system of the Chengdao Offshore Oil Field, and provides new information on the effect factors and mechanisms of corrosion on the offshore oil field.

This paper aims to investigate the influence of sinusoidal texture (ST) with different morphology parameters on the corresponding tribological effects.

The STs with different amplitudes, ranging from 0.05 to 0.3 mm, and frequencies, ranging from 5 to 17.5, are fabricated using nanosecond pulsed laser equipment. The friction experiments and the finite element analysis method are combined to investigate the tribological properties, under dry friction conditions.

Test results show that when the amplitude is 0.15 mm and frequency is 10, ST surface has the lowest friction coefficient of 0.373, and exhibits great anti-friction effect. It also possesses a complete texture edge after friction. The friction reduction effect of ST with larger or smaller amplitude and frequency is worse.

The results of this study can provide a guidance for the design optimization of ST of reciprocating sliding contact surfaces, under dry friction conditions.

The purpose of this paper is to investigate the effect of slip position on the performance of liquid film seal.

A mathematical model of liquid film seal with slip/no-slip surface was established based on the Navier slip model and JFO boundary condition. Liquid film governing equation was discretized by the finite difference method and solved by the SOR relaxation iterative algorithm and the effects of slip position on sealing performance are discussed.

The results indicate that boundary slip plays an important role in the overall performance of a seal and a reasonable arrangement of slip position can improve the steady-state performance of liquid film seal.

Based on the mathematical model, the optimal parameters for liquid film seal with boundary slip at groove are obtained. The results presented in this study are expected to provide a theoretical basis to improve the design method of liquid film seal.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0082/

The purpose of this paper is to get hold of the main influence factors of the investment efficiency of environmental governance and control them to improve its efficiency sensitively and employ full use of the investment of environmental governance.

The assessment index system of the investment efficiency of environmental governance is built. Its investment efficiency is assessed based on data envelopment analysis (DEA). The influence degree on the efficiency between each assessment index is calculated by the grey incidence degree analysis method to find the key influence factors. The efficiency of the investment in the environmental governance can be improved by managing and controlling the key factors.

The results prove that it is available by the data of 14 cities in Shandong Province in 2008. The key influence factors of the investment efficiency of the environmental governance are: total investment in the treatment of environmental pollution (F₁); industrial soot removal (F₃); industrial wastewater meeting discharge standards (F₂); and the volume of garbage disposal (F₉).

The method exposed in the paper can be used to solve investment efficiency problem of the environmental governance of the other provinces, or other years and even other countries.

The paper succeeds in solving investment efficiency problem of the environmental governance by DEA and grey incidence degree analysis method.

Talent is a key resource for urban development, and building and disseminating urban brands have an important impact on attracting talent. This paper explores what kind of urban brand ecology (UBE) can effectively enhance urban talent attraction (UTA). We explore this question using a novel grey quantitative configuration analysis (GQCA) model.

To develop the GQCA model, grey clustering is combined with qualitative configuration analysis (QCA). We conducted comparative configuration analysis of UTA using fuzzy set QCA (fsQCA) and the proposed GQCA.

We find that the empirical results of fsQCA may contradict the facts, and that the proposed GQCA effectively solves this problem.

Based on the theory of UBE, we identify bottleneck factors for improving UTA at different stages. Seven configuration paths are described for cities to enhance UTA. Theoretically, this study expands the application boundaries of UBE.

The proposed GQCA effectively solves the problem of inconsistent analysis and facts caused by the use of a binary threshold by the fsQCA. In practical case studies, the GQCA significantly improves the reliability of configuration comparisons and the sensitivity of QCA to cases, demonstrating excellent research performance.

This study aims to solve the premature failure of the rubber stator due to wear, reduce the frictional resistance moment of the screw pump to solve the problem of a model of Daqing oilfield screw pump oil recovery system shutdown after the difficult start.

For the first time, the rotor surface of a screw pump was treated with dot-matrix texture to study the effect of dot matrix texture on the tribological performance of the stator-rotor friction subsets of screw pump. Reciprocating friction tests with different texture morphologies (S-shape, double tongue) and angular parameters (0°, 45° and 90°) were conducted at 10% of the texture area and pump silicone grease.

When point texture was added to the surface of the rotor sample, the friction coefficient and wear quantity of the sample were lower than those of the surface without texture treatment, and the double tongue 0° combination showed the best tribological properties. At this time, the average coefficient of friction and wear is reduced by 22.8% and 62%, 28.6% and 64.8%.

The introduction of texture can effectively improve the tribological performance of progressive screw pumps, and this paper provides important theoretical and experimental support for the design of progressive screw pumps in practical applications.

The purpose of this paper is to examine the effect of top management’s environmental responsibility audit (ERA) implementation on firms’ investment for environmental protection in China.

The sample comprises firms publicly traded on A-Share in China from 2011 to 2017. The authors used the ordinary least squares regression model to test the relation between ERA implementation and corporate environmental investment.

Firms’ environmental investment increases significantly after the ERA implementation. Compared to state-owned enterprises (SOEs), non-state-owned enterprises (non-SOEs) are more likely to increase their environmental investment after ERA implementation. Moreover, such change is more likely for non-heavily polluting enterprises (non-HPEs) compared to heavily polluting enterprises (HPEs).

This paper provides an in-depth analysis of the positive influence of environmental enforcement on corporate behavior, which could serve as reference for regulators on the latest environmental accounting practice in China and other emerging economies.

This paper shows that clear assignment of environmental responsibility and subsequent assessment of environmental performance are contributing factors to effective and efficient implementation of an environmental management system.

Contributing to accounting and environmental management literature, this paper explains how mandated environmental audit incentivizes firms to deal with environmental issues. Because there is no prior research concerning the mandatory implementation of environmental audit in China, this paper is of high-innovatory value by providing a better understanding of environmental auditing and providing an economic explanation for government intervention as an effective means of mitigating environmental degradation in emerging economies.