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The impact of rolling on the performance of micro arc oxidation (MAO) coatings on ZM5 alloy has been underreported. The purpose of this study is to explore the correlation between rolling and the failure mechanism of MAO coatings in greater depth.

The influence of rolling on the corrosion and wear properties of MAO coating was investigated by phase structure, bond strength test (initial bond strength and wet adhesion), electrochemical impedance spectroscopy and wear test. The change of the surface electrochemical properties was studied by first principles analysis.

The results showed that the MAO coating on rolled alloy had better corrosion and wear resistance compared to cast alloy, although the structure and component content of two kinds of MAO coating are nearly identical. The difference in interface bonding between MAO coating and Mg substrate is the primary factor contributing to the disparity in performance between the two types of samples. Finally, the impact of the rolling process on MAO coating properties is explained through first-principle calculation.

A comprehensive explanation of the impact of the rolling process on MAO coating properties will provide substantial support for enhancing the application of Mg alloy anticorrosion.

The anticorrosion coatings used in marine and atmospheric environment are subjected to many environmental factors. And the aging failure has been puzzling researchers. The purpose of this study is to find the correlation between the initial aging of epoxy coatings and the typical marine atmospheric environmental factors.

The epoxy coatings were subjected to a one-year exposure in three typical marine atmospheres. Meanwhile, principal component analysis, linear regression and Spearman and gray correlation analysis were applied to quantify the environmental characteristics and establish correlations with the coating aging.

The results indicate that the coating will undergo macroscopic fading and chalking upon exposure to the marine atmosphere, while microscopic examination reveals holes, cracks and partial peeling. The adhesion performance and electrochemical properties of the coating deteriorated with prolonged exposure, coating aging mainly occurs with the generation of O-H bonds and the breakage of molecular chains such as C-N and C-O-C. The coating was most deeply aged after exposure to the Xisha, followed by Zhoushan and finally Qingdao. Environmental factors affect the photooxidative aging and hydrolytic degradation processes of coatings and thus coating aging. To further demonstrate the correlation between environmental factors and coating aging, principal component analysis was used. The correlation model between environmental factors and coating aging was subsequently obtained. The correlation model between the rate of coating adhesion loss (E) and the comprehensive evaluation parameter of environmental factors (Z) is expressed as E = 0.142 + 0.028Z. Meanwhile, the Spearman correlation analysis and gray correlation method were used to investigate the impact of each environmental factor on coating aging. Solar irradiation, relative humidity and wetting time have the highest correlation with coating aging, which are all above 0.8 and have the greatest influence on coating aging; wind speed and temperature have the smallest correlation with coating aging, which are about 0.6 and have the least influence on coating aging.

This paper establishes a correlation between typical marine environmental factors and coating aging performance, which is crucial for predicting the service life of other coatings in diverse environments.

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.

Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.

In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.

With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.

Brand microblogs have been adopted as a new approach to promote products or services and maintain relationships with consumers for companies, but literature on why consumers are willing to participate on these microblogs is still relatively limited. The purpose of this study is to examine factors affecting consumers’ participation on brand microblogs and then indicate the underlying mechanism of this process based on elaboration likelihood model (ELM), commitment–trust theory and social presence.

An online survey was conducted in China to investigate consumers who followed brand microblogs. A total of 380 valid responses were collected, and the data were analyzed by the partial least squares structural equation modeling to assess the proposed research model.

The findings show that argument quality and source credibility of a brand microblog are two important factors that enhance consumers’ community commitment and trust toward the microblog, which, in turn, promote their participation intention. In addition, social presence has a moderating effect on the relationship between trust toward brand microblog and participation.

This study extends the understanding regarding consumers’ information adoption processes in brand microblogs from both central and peripheral routes based on ELM. Besides, the role of trust in affecting consumers’ participation and community commitment in the context of brand microblog has been examined from a more detailed perspective. Finally, this paper better reveal the role of social presence in brand communities by focusing on its moderating effect on the relationship between commitment–trust and consumers’ participation. These findings can provide entrepreneurs with insights into strengthening consumers’ participation and operating their brand microblogs in the long-term.

The purpose of this paper is to take the early Permian no.6 coal seam in Jungar coalfield of North China as an example, this paper studied the net primary productivity (NPP) level of the early Permian peatland and its relationship with the atmospheric environment at that time, analyzed the influence of the atmospheric environment, and discussed its control factors.

First, geophysical logging signals were used for a spectrum analysis to obtain the Milankovitch cycle parameters in the no. 6 coal seam, including the eccentricity (95 ka); obliquity (35.6 ka); and precession (21.2 ka). These were then used to calculate the accumulation rate of the residual carbon in the no. 6 coal seam, which was determined to be between 49.44 and 50.57 gC/(m² · a). The carbon loss could be calculated according to the density and residual carbon content of the no. 6 coal seam. Then, the total carbon accumulation rate of the peatland was further derived as being between 64.91 and 66.40 gC/(m² · a). Also, the NPP of the peatland was determined to be between 129.82 and 132.8 gC/(m² · a).

The result showed that the NPP of the early Permian peatland area was lower than that of the Holocene at the same latitude, and also lower than that of the later Permian of South China.

This study’s comprehensive analysis indicated that the temperature and humidity conditions, along with the oxygen and carbon dioxide levels in the atmosphere, were the main control factors of the NPP of the early Permian peatland. Also, wildfires were found to play a role.

First, the authors analyze the key problems faced by the protection of digital library readers' data privacy and behavior privacy. Second, the authors introduce the characteristics of all kinds of existing approaches to privacy protection and their application limitations in the protection of readers' data privacy and behavior privacy. Lastly, the authors compare the advantages and disadvantages of each kind of existing approaches in terms of security, efficiency, accuracy and practicality and analyze the challenges faced by the protection of digital library reader privacy.

In this paper, the authors review a number of research achievements relevant to privacy protection and analyze and evaluate the application limitations of them in the reader privacy protection of a digital library, consequently, establishing the constraints that an ideal approach to library reader privacy protection should meet, so as to provide references for the follow-up research of the problem.

As a result, the authors conclude that an ideal approach to reader privacy protection should be able to comprehensively improve the security of all kinds of readers' privacy information on the untrusted server-side as a whole, under the premise of not changing the architecture, efficiency, accuracy and practicality of a digital library system.

Along with the rapid development of new network technologies, such as cloud computing, the server-side of a digital library is becoming more and more untrustworthy, thereby, posing a serious threat to the privacy of library readers. In fact, the problem of reader privacy has become one of the important obstacles to the further development and application of digital libraries.

This paper aims to explore the effects of leadership style and trust in leadership on employees’ affective commitment under the epidemic situation.

A total of 580 valid questionnaires were collected online targeting the hospitality and tourism employees working from home during the particular period of the COVID-19 Coronavirus crisis. Structural equation modeling was used to analyze the data with AMOS software.

The findings indicated that perceived transformational leadership was a positive predictor of trust in leadership and affective commitment. In addition to the positive contribution to commitment, trust in leadership also mediated the relationship between transformational leadership and organizational commitment.

The current study contributes to the literature on leadership and organizational commitment. The results of this study may provide a valuable guide to organizations, leaders and young employees.

变革型领导对员工信任及员工情感承诺的影响研究

本文旨在研究在新冠疫情背景下, 变革型领导对员工信任度以及情感承诺的影响。

本文研究对象为旅游及酒店行业工作人员, 由于新冠疫情, 调查问卷通过线上的方式向居家办公的酒店工作人员进行发放, 调查结束共收集到580份有效问卷, 利用AMOS软件对收集到的数据进行结构方程分析。

本研究发现, 变革型领导对员工组织信任具有正向影响, 员工信任对员工的组织情感承诺具有正向影响, 变革型领导正向影响员工的组织情感承诺, 并且, 变革型领导通过增强员工信任度, 正向影响员工的组织情感承诺, 即员工信任在变革型领导和情感承诺中间起中介作用。

本研究为拓展企业管理领域研究做出了贡献, 本文研究结果验证了相关的领导理论及组织管理理论, 丰富了职业承诺领域的研究, 为组织、领导以及青年员工的职业发展提供了参考借鉴。

Investigación sobre la influencia del liderazgo transformacional en la confianza y el compromiso emocional de los empleados

Este artículo tiene como objetivo estudiar la influencia del liderazgo transformacional en la confianza y el compromiso emocional de los empleados bajo el impacto del Covid-19.

El objeto de investigación de este artículo es el personal del sector turístico y hotelero. Se recogieron un total de 580 cuestionarios válidos y se analizaron los datos recopilados mediante ecuación estructural utilizando el software AMOS.

Esta investigación encontró que el liderazgo transformacional tiene una influencia positiva en la confianza de los empleados, la confianza de los empleados tiene una influencia positiva en el compromiso emocional de los empleados, el liderazgo transformacional afecta positivamente el compromiso emocional de los empleados y la confianza de los empleados juega un papel intermediario entre el liderazgo transformacional y el compromiso emocional.

Esta investigación enriquece la investigación sobre la teoría del liderazgo y el compromiso organizacional, y proporciona una referencia para el desarrollo profesional de organizaciones, líderes y empleados jóvenes.

This study aims to explore the impact of key parameters of brake pads on the dynamic characteristics of the braking system.

This study conducted experimental research based on a friction testing machine with a slider-disc structure. The experiment studied the impact of key parameters of brake pads (rotation speed, pressure, mass, braking radius, etc.) and the braking environment (dry friction, wetness, sand, etc.) on the stability of the braking system. At the same time, a dynamic model of the brake pad braking system was established and compared with experimental results using the mathematical tool of autocorrelation coefficient.

The key parameters of brake pads have a significant impact on the dynamic characteristics of the braking system; under different conditions of brake pad mass, tribological parameters, brake pad radius and braking environment, the chaotic characteristics of the braking friction force signal show a trend of expansion or contraction, which can be suppressed by adjusting the key parameters of brake pads.

This study can provide a reference for optimizing the braking strategy and reducing noise and vibration in brake pad systems.

Although high-order smooth reproducing kernel mesh-free approximation enables the analysis of structural vibrations in an efficient collocation formulation, there is still a lack of systematic theoretical accuracy assessment for such approach. The purpose of this paper is to present a detailed accuracy analysis for the reproducing kernel mesh-free collocation method regarding structural vibrations.

Both second-order problems such as one-dimensional (1D) rod and two-dimensional (2D) membrane and fourth-order problems such as Euler–Bernoulli beam and Kirchhoff plate are considered. Staring from a generic equation of motion deduced from the reproducing kernel mesh-free collocation method, a frequency error measure is rationally attained through properly introducing the consistency conditions of reproducing kernel mesh-free shape functions.

This paper reveals that for the second-order structural vibration problems, the frequency accuracy orders are p and (p − 1) for even and odd degree basis functions; for the fourth-order structural vibration problems, the frequency accuracy orders are (p − 2) and (p − 3) for even and odd degree basis functions, respectively, where p denotes the degree of the basis function used in mesh-free approximation.

A frequency accuracy estimation is achieved for the reproducing kernel mesh-free collocation analysis of structural vibrations, which can effectively underpin the practical applications of this method.

To improve the accuracy of the industrial robots’ absolute positioning, a Kriging calibration is proposed.

This method particularly designs a semivariogram for connecting the joint space and the working space. After that, Kriging equations are determined and solved to predict the position errors of targets. Subsequently, a simple and convenient error compensation, which can be implemented on the control command, is proposed.

The verification experiment of the position-error multiplicity and the Kriging calibration experiment are done in the KUKA R210 R2700 industrial robot. The position-error multiplicity experiment reveals that the position error of the industrial robot varies with the joint angle sets. Besides, the Kriging calibration experiment shows that the maximum of the spatial position errors is reduced from 1.2906 to 0.2484 mm, which reveals the validity of the Kriging calibration.

The special designed semivariation allows this method to be flexible and practical. It can be used in various fields where the angle solutions of industrial robots should be adapted according to the optimal demand and the environment, such as the optimal trajectory planning and the obstacle avoidance. Besides, this method can provide accuracy positioning results.