Search results

The purpose of this paper is to explore the effect of ZnO on the structure and properties of micro-arc oxidation (MAO) coating on rare earth magnesium alloy under large concentration gradient.

The macroscopic and microscopic morphology, thickness, surface roughness, chemical composition and structure of the coating were characterized by different characterization methods. The corrosion resistance of the film was studied by electrochemical and scanning Kelvin probe force microscopy. The results show that the addition of ZnO can significantly improve the compactness and corrosion resistance of the MAO coating, but the high concentration of ZnO will cause microcracks, which will reduce the corrosion resistance to a certain extent.

When the concentration of zinc oxide is 8 g/L, the compactness and corrosion resistance of the coating are the best, and the thickness of the coating is positively correlated with the concentration of ZnO.

Too high concentration of ZnO reduces the performance of MAO coating.

The MAO coating prepared by adding ZnO has good corrosion resistance. Combined with organic coatings, it can be applied in corrosive marine environments, such as ship parts and hulls. To a certain extent, it can reduce the economic loss caused by corrosion.

The effect of ZnO on the corrosion resistance of MAO coating in electrolyte solution was studied systematically, and the conclusion was new to the common knowledge.

The present study aims to ascertain the relationships between subordinate moqi and leader behaviors, by primarily discussing how and when subordinate moqi is associated with leadership empowerment.

A self-report study was conducted by recruiting 334 employees from 13 firms. All concepts were rated on a seven-point Likert-type response scale. Linear regression analysis (conducted in MPLUS 7) was conducted to verify the hypotheses.

First, subordinate moqi showed positive association with empowerment. Second, trust-in-supervisor mediated the relationships between subordinate moqi and empowerment. Third, subordinates' power distance orientation (PDO) could moderate the subordinate moqi – leader empowerment relationship. When subordinates reported higher PDO, the relationships between subordinate moqi and empowerment were more robust; likewise, subordinate moqi would have more significantly indirectly impacted empowerment via trust-in-supervisor.

Though researchers have discussed the impacts of subordinate moqi on subordinates' outcomes, the impact of subordinate moqi on supervisors' attitudes or behaviors remains unclear. The relationships between subordinate moqi and supervisor empowerment behaviors are empirically ascertained by emphasizing the leader-subordinate dyadic process. The findings here suggested that subordinate moqi boosted subordinates' trust-in-supervisor, and moqi would also predict the behaviors of leader empowerment. This study extended the PDO literature by identifying the moderating role of PDO in the subordinate moqi – leader empowerment behavior relationship.

With the continuous growth of online education, the quality issue of online educational videos has become increasingly prominent, causing students in online learning to face the dilemma of knowledge confusion. The existing mechanisms for controlling the quality of online educational videos suffer from subjectivity and low timeliness. Monitoring the quality of online educational videos involves analyzing metadata features and log data, which is an important aspect. With the development of artificial intelligence technology, deep learning techniques with strong predictive capabilities can provide new methods for predicting the quality of online educational videos, effectively overcoming the shortcomings of existing methods. The purpose of this study is to find a deep neural network that can model the dynamic and static features of the video itself, as well as the relationships between videos, to achieve dynamic monitoring of the quality of online educational videos.

The quality of a video cannot be directly measured. According to previous research, the authors use engagement to represent the level of video quality. Engagement is the normalized participation time, which represents the degree to which learners tend to participate in the video. Based on existing public data sets, this study designs an online educational video engagement prediction model based on dynamic graph neural networks (DGNNs). The model is trained based on the video’s static features and dynamic features generated after its release by constructing dynamic graph data. The model includes a spatiotemporal feature extraction layer composed of DGNNs, which can effectively extract the time and space features contained in the video's dynamic graph data. The trained model is used to predict the engagement level of learners with the video on day T after its release, thereby achieving dynamic monitoring of video quality.

Models with spatiotemporal feature extraction layers consisting of four types of DGNNs can accurately predict the engagement level of online educational videos. Of these, the model using the temporal graph convolutional neural network has the smallest prediction error. In dynamic graph construction, using cosine similarity and Euclidean distance functions with reasonable threshold settings can construct a structurally appropriate dynamic graph. In the training of this model, the amount of historical time series data used will affect the model’s predictive performance. The more historical time series data used, the smaller the prediction error of the trained model.

A limitation of this study is that not all video data in the data set was used to construct the dynamic graph due to memory constraints. In addition, the DGNNs used in the spatiotemporal feature extraction layer are relatively conventional.

In this study, the authors propose an online educational video engagement prediction model based on DGNNs, which can achieve the dynamic monitoring of video quality. The model can be applied as part of a video quality monitoring mechanism for various online educational resource platforms.

The unitized curtain wall system (UCWS), one of the prefabricated technologies, is increasingly attracting attention in the Hong Kong construction industry. However, this innovative technology still lacks on-site implementation in high-rise residential buildings. To promote its development, this study aims at identifying the influential factors of UCWS adoption in Hong Kong's high-rise residential buildings from a multi-stakeholder perspective.

Factors were first selected through an in-depth literature review and a semi-structured interview. Then the factors were validated through a questionnaire survey using Cronbach's Alpha Reliability Test. Next, the factors were ranked regarding their importance using mean-score ranking and standard deviation. Meanwhile, different stakeholders were clustered using an experimental factor analysis (EFA) model to find the shared preferences (namely common factors).

The result shows that reduction of construction time (B1) and insufficient site storage area (C1) are the most important factors. The six stakeholder groups were clustered into two segments. B1 and improved quality control are the shared interests. While C1 and the need of specification change are the common concerns.

There are two major breakthroughs in this study. First is the novelty of research objects. UCWS, particularly its application preference in high-rise residential buildings, has rarely been studied, yet it is urgently required. Second is the novel research perspective. The influential factors were studied from a multi-stakeholder perspective. Not only the significant factors for six specific stakeholders but also the shared preference for stakeholder groups was identified. The findings contribute to promoting UCWS more targeted, efficient and comprehensive, as well as demonstrating the collaborative possibilities of multi-stakeholders.

The unitized curtain wall system (UCWS), a symbol of modern architecture, is gaining popularity among prefabricated components. Previous studies have focused on both construction technology advances and material selection strategies to facilitate the UCWS. However, the topic of client satisfaction, which drives industry development by targeting clients' demands, has gone unnoticed. Therefore, the current study aims to investigate client satisfaction with UCWS products in Hong Kong by finding its influential factors.

A systematic review was employed to first identify the influential factors. A semi-structured interview was employed to validate the reliability of the extracted factors. The machine learning algorithm Extreme Gradient Boosting (XGBoost) and the Pearson correlation were then employed to rank the importance and correlation of factors based on the 1–5 Likert scale scores obtained through a questionnaire survey.

The findings revealed that “reduction in construction time” and “reduction in construction waste” are the most important factors and have a strong positive influence on client satisfaction.

Unlike previous studies, the present study focused on a novel research topic and introduces an objective analysis process using machine learning algorithms. The findings contribute to narrowing the knowledge gap regarding client preference for UCWS products from both individual and collaborative perspectives, providing decision-makers with an objective, quantitative and thorough reference before making investments in the curtain wall management development.

To explore substitutes for traditional Sn-Pb solder, Sn-20In-2.8Ag was considered because of its appropriate melting temperature, good reliability and high ductility at less than 100°C. However, the mechanical properties of Sn-20In-2.8Ag were not satisfactory. The reason for the poor mechanical properties of the Sn-20In-2.8Ag/Cu joint was revealed, and a way to solve the problem was found.

The microstructure evolution, characteristics of melting and solidification and joining performance with Cu were investigated using scanning electron microscopy (SEM), electron probe microanalysis, differential scanning calorimetry (DSC) and mechanical testing.

SEM results showed that the microstructure of Sn-20In-2.8Ag was composed of coarse dendritic Ag₂In and γ phases, with Ag₂In distributed at the grain boundaries. DSC measurements revealed that small amount of low temperature eutectic reaction, L → Ag₂In + β + γ, occurred at 112.9°C. This reaction was caused by the segregation of indium, which is a process that has a strong driving force. In the lap-shear testing, a crack propagated along the grain boundary of the solder, and failure showed an intergranular fracture. This failure was connected with the three-phase eutectic and coarse Ag₂In. Thus, to improve the mechanical properties, segregation of indium should be reduced and coarsening of Ag₂In should be prevented.

The reason for the unsatisfactory mechanical properties of Sn-20In-2.8Ag was revealed via microstructural observations and solidification analysis, and the way to solve this problem was found.

China has experienced a fast economic growth and shown a significant rise in income inequality in the past decades. During the same period, fluid milk consumption in urban areas has rapidly expanded. The objective of this paper is to analyze and simulate the influence of income distribution changes on fluid milk consumption of households in urban China.

This study applies an inverse hyperbolic sine (IHS) double-hurdle model to modeling at-home fluid milk consumption of households across different income strata based on a sample of 11,861 urban households in five provinces in China, and simulating the impact of changing income distribution, including five income growth patterns, on fluid milk consumption of total households as well as specific household groups.

The fluid milk consumption in urban China will continue to increase, with the unconditional income elasticity being 0.334 for the full sample and 0.347, 0.335 and 0.162 for the low-, middle-, and high-income groups, respectively. The simulation results show an evidence that, compared with distribution-neutral and disparity-enlarging income growth patterns, a rising income equality would lead to a more significant increase in fluid milk consumption. And the inequality-reducing income growth pattern has a larger impact on fluid milk consumption of households with seniors and no children, as well as households having no local urban household registration (hukou).

The government should strengthen the supply measures of fluid milk in urban areas, enlarge domestic dairy production, and diversify the sources of milk imports. It is also necessary to subsidize low-income families, especially households with seniors or households migrated from other areas without getting local urban hukou, which could simultaneously improve nutritional benefits and alleviate financial pressures.

A simulation considering the evolution of income distribution as well as different household groups is conducted. Widely distributed data with a large sample size and detailed demographic information are used. The problems of zero consumption and non-normal distribution are addressed by the IHS double-hurdle model.

Music mood is an important metadata type on online music repositories and stream music services worldwide. Many existing studies on mood metadata have focused on music websites and services in the Western world to the exclusion of those serving users in other cultures. The purpose of this paper is to bridge this gap by exploring mood labels on influential Chinese music websites.

Mood labels and the associated song titles were collected from six Chinese music websites, and analyzed in relation to mood models and findings in the literature. An online music listening test was conducted to solicit users’ feedback on the mood labels on two popular Chinese music websites. Mood label selections on 30 songs from 64 Chinese listeners were collected and compared to those given by the two websites.

Mood labels, although extensively employed on Chinese music websites, may be insufficient in meeting listeners’ needs. More mood labels of high arousal semantics are needed. Song languages and user familiarity to the songs show influence on users’ selection of mood labels given by the websites.

Suggestions are proposed for future development of mood metadata and mood-enabled user interfaces in the context of global online music access.

This paper provides insights on understanding the mood metadata on Chinese music websites and uniquely contributes to existing knowledge of culturally diversified music access.

This paper aims to explore the impact of green finance on the heterogeneity of enterprise green technology innovation and the underlying mechanism between them.

Using the data of China's A-share listed enterprises from 2008 to 2020 and the fixed effect model, the authors empirically explore the relationship and mechanism between green finance and green technology innovation by constructing the green finance index while considering both the quality and quantity of innovation.

The study suggests that green finance is positively related to the quality and quantity of enterprise green technology innovation, while green finance is more effective in stimulating the quality of green technology innovation than quantity. In addition, alleviating financial mismatch and improving the quality of environmental information disclosure are core mechanisms during the process of green finance facilitating green technology innovation. Furthermore, green finance exerts a more positive effect on the quality and quantity of green technology innovation with large-size enterprises, heavily polluting industries and enterprises in the eastern region.

This paper enriches the literature on green finance and green technology innovation and provides practical significance for green finance implementation.

The purpose of this paper is to examine the uniqueness of management development in China during 1990 and 2010 as represented by the MBA education, and to explore its successes and challenges in the Chinese transitioning context.

The authors adopted an approach that integrated content analysis of literature, historical data and interviews.

It was found that successful practices such as the National MBA Education Supervisory Committee, the top‐down approach by the government, the emphasis on international collaborations and faculty development, national MBA entrance examinations, and other related measures have maintained the MBA education system on its current development course, while challenges from the ever‐changing context, the balance between internationalization and localization, curriculum design with the Chinese characteristics will continue to shape the future of MBA education in China.

Copying from others for management development in the initial stage may be feasible, but it is the localization that ensures flexibility and sustainability.

There has been insufficient systematic assessment of MBA education in China. This paper examined MBA practices and challenges in the past two decades of development and offers policy implications for future program development.