Yanfei Yang, Xiaobo Wang, Sen Mei, Xing Zhu, Shiqiang Chen, Peng Xiong, Zhihai Hu, Kun Xiong and Dong Song Yuan
The purpose of this paper is to investigate the tribological performance and mechanisms of BN/calcium borate nanocomposites (BCBNs) as additives in lubricating oil.
Abstract
Purpose
The purpose of this paper is to investigate the tribological performance and mechanisms of BN/calcium borate nanocomposites (BCBNs) as additives in lubricating oil.
Design/methodology/approach
BCBNs were prepared by heterogeneous deposition method. And the morphology and structure of samples were analysed by transmission electron microscopy, Fourier transform infrared spectra and X-ray powder diffraction pattern. The maximum non-seizure load (PB) of samples was tested using four-ball friction tester. The average friction coefficients and wear tracks were obtained. In addition, tribological mechanism was also investigated using optical microscope, energy dispersive spectroscopy and X-ray photoelectron spectroscope.
Findings
It was found that the nanocomposites present core-shell nanostructure with the thickness of shell around 12 nm and the diameter of particles 100-200 nm, and tribological tests indicate that the PB value of BCBNs was increased by 113 per cent, whereas the average friction coefficient was decreased by 23.6 per cent and the bloom’s wear area was also decreased by 25.2 per cent.
Originality/value
This paper involves investigation on tribological properties and mechanism of the BCBNs with core-shell structure.
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Li‐zhu Liu, Hong‐jie Ma, Xing‐song Zhu, Yu‐jiang Fan and Zhen‐hao Jin
Polylactide/nano‐silica in situ composites are synthesised and characterised in order to study their mechanical and thermal properties. The purpose of this paper is to study these…
Abstract
Purpose
Polylactide/nano‐silica in situ composites are synthesised and characterised in order to study their mechanical and thermal properties. The purpose of this paper is to study these properties and compare them with the pure polylactide (PLA).
Design/methodology/approach
Polylactide/nano‐silica in situ composites are synthesised from lactide and modified nano‐silica using stannous octoate as a catalyst. The structure and properties of the composites are characterised by gel permeation chromatography (GPC), thermal gravimetric analysis (TGA) and scanning electronic microscopy (SEM).
Findings
The results of SEM showed that nano‐silica and PLA are connected with covalent bonds, and that inorganic phases are dispersed homogeneously in the PLA matrix. The results of TGA indicated that the thermal decomposition temperature rose with the increase of silica content. The tensile strength of the composites is enhanced because of the addition of nano‐inorganic particles into PLA.
Research limitations/implications
Although the preparation process is simplified by a two‐step method, attempts will be made to synthesise the polylactide/nano‐silica composites by a one‐step approach to curtail the preparation cycle.
Practical implications
The composites are expected to be suitable for applications in packaging materials, biomedical and pharmaceutical fields.
Originality/value
Preparation of polylactide/nano‐silica composites is expected to exert the respective advantages of the two ingredients and to produce more practical polymer materials.
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Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance transcends…
Abstract
Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance transcends generations, allowing space and structure to evolve through time. This paper investigates the relationship among main building structures, infill elements, and space by studying examples in ancient Chinese architecture. It reveals the role of building owners, users, and craftsmen from a survey of historical documentation. In studying these examples, it is concluded that craftsmen in ancient China were involved not only during the construction phase but throughout the period of use as well. Thus, in select cases, the relationship between craftsmen and owners or users had been preserved for generations. Finally, this paper suggests potential strategies for the building industry and technology in the move towards sustainable development.
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Shuang Ren and Ying Zhu
– The purpose of this paper is to explore the contemporary paradigm of business leadership vis-à-vis China’s reform and transitional context.
Abstract
Purpose
The purpose of this paper is to explore the contemporary paradigm of business leadership vis-à-vis China’s reform and transitional context.
Design/methodology/approach
The paper employs an evidence-based approach to explore the business leadership issues influenced by economic reform and within the context of societal transition in China. A qualitative research method was adopted based on in-depth interviews with a number of middle managers from a variety of Chinese enterprises, including state-owned, domestic-private and foreign-invested enterprises. Content analysis of several rounds of interviews added depth to the data analysis.
Findings
The findings complement existing thoughts and illustrate concepts, issues, and characteristics not yet emphasized in mainstream literature. General patterns and associated characteristics of business leadership in China, as well as specific patterns associated with different forms of enterprise ownerships, are identified.
Research limitations/implications
The study makes a timely and necessary contribution that enriches context-specific understandings of business leadership against the backdrop of surrounding economic, social, and cultural changes.
Practical implications
The study enriches understandings of commonalities and differences in leadership across the globe, facilitating working collaboratively to achieve common goals in a global community.
Originality/value
The study offers new insights into business leadership by linking contextual, personal, and cognitional factors together and demonstrates some unique characteristics of leadership styles in transitional economies like China.
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The author provides us here with a rare and original testimony about the Democratic People’s Republic of Korea, from the trips he was able to make there and the many contacts he…
Abstract
The author provides us here with a rare and original testimony about the Democratic People’s Republic of Korea, from the trips he was able to make there and the many contacts he had there. He focuses the readers’ attention more particularly on his interpretation of Juche’s thinking, the principles of which contribute to find the development strategy of this country. The emphasis is primarily on the imperative of autonomy for the economy and the society.
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Elena Fedorova, Pavel Drogovoz, Alexandr Nevredinov, Polina Kazinina and Cai Qitan
The goal of the study is to examine the effects of management discussion and analysis (MD&A) sentiment in public companies' annual reports on corporate investment incentives in…
Abstract
Purpose
The goal of the study is to examine the effects of management discussion and analysis (MD&A) sentiment in public companies' annual reports on corporate investment incentives in developing economies.
Design/methodology/approach
The authors use sentiment analysis of MD&A texts based on Loughran and McDonald (2011) and combination of panel data regression, logit model and random forest. The text data consists of 3,511 annual reports of Chinese listed companies for the period from 2010 to 2019.
Findings
This paper provides empirical evidence of signaling theory that sentiment of annual reports and MD&A influences corporate decisions on both M&A and internal investments. The authors found that comparing to annual reports MD&A sentiment has more stable and significant explanatory and predictive power.
Practical implications
This paper confirms the importance of MD&A sentiment for corporate investment decision taking and provides practical techniques for analysts and researchers to study corporate investment incentives from the point of view of signaling theory.
Originality/value
The study aims to expand the domains of signaling theory and corporate investment valuation by including a broader range of data on companies' M&A and internal investments in developing economies. To explore the impact of MD&A sentiment on corporate investment, a state-of-the-art set of text mining and machine learning techniques is used. The authors' results confirm that MD&A has signaling effect and can get a positive market response. Furthermore, this study enhances the empirical evidence of overconfidence theory, i.e. optimistic management whose MD&A tend to positive overestimates the management's investments decision and also underestimate the potential risk to the firm.
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Sheng Peng, Lu-jun Cai, Tian-hua Jiang and Xu Kai
The purpose of this paper is to investigate the explosive performance and explosion damage mechanism of T-beam bridge structure.
Abstract
Purpose
The purpose of this paper is to investigate the explosive performance and explosion damage mechanism of T-beam bridge structure.
Design/methodology/approach
On the basis of the existing specification, two T-beam bridge models were designed and fabricated. Test specimens of different explosive dosage and different blast height were carried out. The mechanical process, failure mode, blast damage model, damage identification mechanism and blast evolution law and quantitative evaluation were taken into account.
Findings
The results revealed that the web plate fracture failure is the key to the unstable failure of the whole T-beam bridge. The explosion failure phenomenon and blast damage evaluation criterion of RC T-beam bridge was divided into five stages: the original cracks stage of concrete material (D = 0 ∼ 0.1), the fractures initiation stage of concrete material (D = 0.1 ∼ 0.3), the stable expansion stage of cracks in concrete material (D = 0.3 ∼ 0.55), the unstable expansion stage of cracks in concrete material (D = 0.55 ∼ 0.8), the explosion fracture of steel bars and the overall instability and damage of the bridge (D = 0.8 ∼ 1.0), which can also be described as basically intact, slight damage, moderate damage, severe damage and collapsed.
Social implications
The research result will provide basis for the antiknock evaluation and damage repair technical specifications of the RC T-beam bridge.
Originality/value
The research results of damage evaluation serve as a basis for damage repair and reinforcement of bridge structures after explosion.
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Maojian Chen, Xiong Luo, Hailun Shen, Ziyang Huang, Qiaojuan Peng and Yuqi Yuan
This study aims to introduce an innovative approach that uses a decoder with multiple layers to accurately identify Chinese nested entities across various nesting depths. To…
Abstract
Purpose
This study aims to introduce an innovative approach that uses a decoder with multiple layers to accurately identify Chinese nested entities across various nesting depths. To address potential human intervention, an advanced optimization algorithm is used to fine-tune the decoder based on the depth of nested entities present in the data set. With this approach, this study achieves remarkable performance in recognizing Chinese nested entities.
Design/methodology/approach
This study provides a framework for Chinese nested named entity recognition (NER) based on sequence labeling methods. Similar to existing approaches, the framework uses an advanced pre-training model as the backbone to extract semantic features from the text. Then a decoder comprising multiple conditional random field (CRF) algorithms is used to learn the associations between granularity labels. To minimize the need for manual intervention, the Jaya algorithm is used to optimize the number of CRF layers. Experimental results validate the effectiveness of the proposed approach, demonstrating its superior performance on both Chinese nested NER and flat NER tasks.
Findings
The experimental findings illustrate that the proposed methodology can achieve a remarkable 4.32% advancement in nested NER performance on the People’s Daily corpus compared to existing models.
Originality/value
This study explores a Chinese NER methodology based on the sequence labeling ideology for recognizing sophisticated Chinese nested entities with remarkable accuracy.
Details
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Feliza Marie Santos Mercado and Sungwon Shin
In response to challenges in traditional professional development, educators are increasingly utilizing social media platforms to customize their learning experiences and…
Abstract
Purpose
In response to challenges in traditional professional development, educators are increasingly utilizing social media platforms to customize their learning experiences and facilitate their professional growth. This systematic literature review seeks to examine articles published between January 2018 and July 2023 to synthesize evidence on the ways in which teachers are leveraging social media to improve their teaching practices.
Design/methodology/approach
The authors used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to guide the literature review process. First, the authors established synthesis questions, set up eligibility criteria and determined search engines and search terms to identify the relevant literature. Second, the authors sorted and selected from the preliminary article search and screened based on the established criteria. Finally, the authors analyzed each selected article’s content, which included coding, interpreting the themes and organizing the findings.
Findings
Teachers are increasingly using social media for professional development, engaging in collaboration, empowering connection, and relationship-building through teacherpreneurship. They take on various roles, from info-consumers and info-networkers to self-seeking contributors, vocationalists and lurkers. Despite these benefits, challenges remain, such as potential for unexpected misunderstandings, social comparison that can lead to low self-esteem, which can hinder effective engagement in social media-based professional development. Additionally, this paper observed a growing trend in scholarly articles on this topic, particularly from 2020, 2021 and 2022, highlighting its increasing relevance and impact on the educational community.
Research limitations/implications
This systematic literature review focused exclusively on studies involving in-service K-12 teachers as participants, excluding perspectives from preservice teachers, higher education instructors, instructional coaches and school administrators. While these other educational professionals undoubtedly offer valuable insights into improving teaching practices and contribute significantly to social media-based professional development, this review aimed to center the experiences of K-12 in-service teachers to understand their unique professional development needs and practices. Consequently, it does not capture the potential synergies between K-12 teachers and other educator groups, such as the ways in which school administrators might support or enhance in-service teachers’ professional development through social media. Future studies could explore these interactions more deeply to provide a fuller picture of the collective expertise within these groups.
Practical implications
The COVID-19 pandemic underscored the value of social media for informal professional development, as shown by the increased number of publications on this topic during that period. However, some social media platforms prioritize consumerism over educational resources, emphasizing the need for educators to critically evaluate their sources. Teachers should be discerning in their resource selection, ensuring that educational references are credible and free of hidden costs.
Social implications
This study uncovered several unique patterns in how teachers use social media, revealing both benefits and challenges. Notably, some teachers are leveraging social media not only to build professional connections but also to engage in commercial activities. While this practice can create a supportive network – where teachers promote one another’s visibility, share products and seek support – it can also detract from the intended purpose of professional learning. The focus on brand-building and profit-making may overshadow authentic community-building and collaborative growth. Additionally, the presence of paid content introduces financial barriers, as many teachers have limited resources for professional development.
Originality/value
This study provides a comprehensive review of recent literature (January 2018 to July 2023) on teachers' use of social media for professional development and learning, offering fresh insights into emerging trends. Notably, findings of this study highlight the role of teacherpreneurship in fostering beneficial social connections within digital spaces, a factor that has gained prominence as teachers seek collaborative and supportive networks. Additionally, this research sheds light on lurking as a common strategy among teachers to avoid conflict and misunderstandings when engaging in social media-based professional development. Furthermore, by addressing various challenges, this paper presents suggestions for thoughtfully integrating social media into school professional development programs, with the intention of supporting the diverse needs of teachers and fostering their professional growth.
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Rumeysa Çölden Akgül and Güleda Doğan
This study aims to evaluate the current situation of the interlibrary loan in Türkiye using interlibrary loan tracking system raw data (2008–2019). Data was analyzed…
Abstract
Purpose
This study aims to evaluate the current situation of the interlibrary loan in Türkiye using interlibrary loan tracking system raw data (2008–2019). Data was analyzed geographically to reveal the effect of geographical distance on the collaboration and thematically to identify the prominent areas/topics in the requests. In addition, the requests were evaluated in terms of the type and age of the university, the size of the collection and the number of library users.
Design/methodology/approach
The effect of geographical distance on the collaboration was revealed using VOSviewer. The place numbers and titles of the requests were used for thematic analysis, which was performed using Flourish and VOSviewer. Statistical tests were conducted with SPSS to investigate the effects of factors such as university age and type.
Findings
Geographic analysis revealed that the prominent regions are Marmara, Central Anatolia and Aegean Regions, respectively. The fact that these regions host Türkiye’s largest cities with the highest number of universities has been effective in achieving this result. The results of the thematic analysis are in accordance with the literature. Almost half of the requests are from Social Sciences, Language and Literature, History and Law. While the effects of collection size and the number of library users have relatively insignificant effects on requests, age and university type were found to be more relevant.
Originality/value
Interlibrary loan data of this size has not been the subject of an evaluation before in Türkiye. Hence, the results obtained have the potential to influence relevant policies and decisions on the subject. On the other hand, to the best of the authors’ knowledge, bibliographic mapping was used for the first time on interlibrary loan data.