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Article
Publication date: 4 May 2021

Xin Feng, Hanshui Zhang, Yue Zhang, Liming Sun, Jiapei Li and Ye Wu

The emergence of a coronavirus disease 2019 (COVID-19) epidemic has had a tremendous impact on the world, and the characteristics of its evolution need to be better understood.

Abstract

Purpose

The emergence of a coronavirus disease 2019 (COVID-19) epidemic has had a tremendous impact on the world, and the characteristics of its evolution need to be better understood.

Design/methodology/approach

To explore the changes of cases and control them effectively, this paper analyzes and models the fluctuation and dynamic characteristics of the daily growth rate based on the data of newly confirmed cases around the world. Based on the data, the authors identify the inflection points and analyze the causes of the new daily confirmed cases and deaths worldwide.

Findings

The study found that the growth sequence of the number of new confirmed COVID-19 cases per day has a significant cluster of fluctuations. The impact of previous fluctuations in the future is gradually attenuated and shows a relatively gentle long-term downward trend. There are four inflection points in the global time series of new confirmed cases and the number of deaths per day. And these inflection points show the state of an accelerated rise, a slowdown in the rate of decline, a slowdown in the rate of growth and an accelerated decline in turn.

Originality/value

This paper has a certain guiding and innovative significance for the dynamic research of COVID-19 cases in the world.

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Article
Publication date: 8 March 2021

Xin Feng, Liangxuan Li, Jiapei Li, Meiru Cui, Liming Sun and Ye Wu

This paper aims to study the characteristics and evolution rules of tagging knowledge network for users with different activity levels in question-and-answer (Q&A…

Abstract

Purpose

This paper aims to study the characteristics and evolution rules of tagging knowledge network for users with different activity levels in question-and-answer (Q&A) community represented by Zhihu.

Design/methodology/approach

A random sample of issue tag data generated by topics in the Zhihu network environment is selected. By defining user quality and selecting the top 20% and bottom 20% of users to focus on, i.e. top users and bot users, the authors apply time slicing for both types of data to construct label knowledge networks, use Q-Q diagrams and ARIMA models to analyze network indicators and introduce the theory and methods of network motif.

Findings

This study shows that when the power index of degree distribution is less than or equal to 3.1, the ARIMA model with rank index of label network has a higher fitting degree. With the development of the community, the correlation between tags in the tagging knowledge network is very weak.

Research limitations/implications

It is not comprehensive and sufficient to classify users only according to their activity levels. And traditional statistical analysis is not applicable to large data sets. In the follow-up work, the authors will further explore the characteristics of the network at a larger scale and longer timescale and consider adding more node features, including some edge features. Then, users are statistically classified according to the attributes of nodes and edges to construct complex networks, and algorithms such as machine learning and deep learning are used to calculate large-scale data sets to deeply study the evolution of knowledge networks.

Practical implications

This paper uses the real data of the Zhihu community to divide users according to user activity and combines the theoretical methods of statistical testing, time series and network motifs to carry out the time series evolution of the knowledge network of the Q&A community. And these research methods provide other network problems with some new ideas. Research has found that user activity has a certain impact on the evolution of the tagging network. The tagging network followed by users with high activity level tends to be stable, and the tagging network followed by users with low activity level gradually fluctuates.

Social implications

Research has found that user activity has a certain impact on the evolution of the tagging network. The tagging network followed by users with high activity level tends to be stable, and the tagging network followed by users with low activity level gradually fluctuates. For the community, understanding the formation mechanism of its network structure and key nodes in the network is conducive to improving the knowledge system of the content, finding user behavior preferences and improving user experience. Future research work will focus on identifying outbreak points from a large number of topics, predicting topical trends and conducting timely public opinion guidance and control.

Originality/value

In terms of data selection, the user quality is defined; the Zhihu tags are divided into two categories for time slicing; and network indicators and network motifs are compared and analyzed. In addition, statistical tests, time series analysis and network modality theory are used to analyze the tags.

Details

Information Discovery and Delivery, vol. 49 no. 2
Type: Research Article
ISSN: 2398-6247

Keywords

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Article
Publication date: 16 March 2021

Xin Feng, Liming Sun, Yuehao Liu, Jiapei Li and Ye Wu

This paper aims to explore the development trend of OA articles and their advantages and disadvantages in the process of fighting the pandemic, and conduct a multi-level…

Abstract

Purpose

This paper aims to explore the development trend of OA articles and their advantages and disadvantages in the process of fighting the pandemic, and conduct a multi-level and multi-angle analysis of the relationship between publishing costs and the influence of OA articles.

Design/methodology/approach

This study first compares the total number of articles in Web of Science with the number of OA articles, and the total number of COVID-19 related articles with the total number of OA articles. Subsequently, using the methods of institutional cooperation co-occurrence network, keyword co-occurrence and multidimensional scale analysis, and using the literature on the topic of COVID-19 in CNKI (Chinese National Knowledge Infrastructure) as the data set, we generate visualized maps of research results distribution and keyword co-occurrence network with the help of the Statistical Analysis Toolkit for Infometrics (SATI)

Findings

The research results show that the citation frequency and use frequency of OA articles related to COVID-19 are significantly higher than that of non-OA articles. OA articles dominate in the anti-pandemic process, with a series of advantages such as short review cycle, timeliness, high social benefit, high participation and fast dissemination playing an important role. Under the model of author's non-payment for OA article, the degree of institutional cooperation and author cooperation is enhanced, which improves the fluidity of knowledge, strengthens close links between keywords and enhances significant academic influence; OA articles will continue to promote research in the field of COVID-19, but the lack of quality of some OA articles may hinder their development. Then OA articles will further focus on clinical medicine, and related results will continue to promote the development and communication of OA articles in this field.

Originality/value

Corresponding measures are also proposed for the existing problems of OA articles, to provide a reference for the publication and dissemination of OA articles in public health emergencies in the future.

Details

Library Hi Tech, vol. 39 no. 3
Type: Research Article
ISSN: 0737-8831

Keywords

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Article
Publication date: 4 June 2021

Jiapei Li, Liming Sun, Xin Feng, Peiyi He and Yue Zhang

This paper takes the current COVID-19 pandemic raging around the world as a realistic background and uses the informal scientific communication mode in social media as the…

Abstract

Purpose

This paper takes the current COVID-19 pandemic raging around the world as a realistic background and uses the informal scientific communication mode in social media as the theoretical basis. It aims to explore the characteristics and rules of scientific communication in social media under emergency events, grasp the potential and risks of scientific communication in social media in special times and provide a perspective of academic communication for the scientific response.

Design/methodology/approach

The authors select the enumeration data of the early COVID-19 theme papers spread on social media networks as the research object, apply descriptive statistical analysis to the basic statistical distribution of variables and use factor analysis and visualization methods to explore the law and characteristics of the spread of scientific papers on social media platforms.

Findings

It was found that users of the COVID-19 paper are mainly in North America, Europe and South America, followed by those in East Asia, Southeast Asia and Oceania. The users are mainly public figures, doctors and other practitioners, science communicators and scientists. The process of social media communication reflects three ways of knowledge construction, social interaction and academic communication, and there are three ways of communication law and changing trend of cross transition and integration.

Originality/value

This study observes the function and role of science communication in social media in a special period from a unique perspective of academic communication, so as to promote academic means to fight against the epidemic.

Details

Library Hi Tech, vol. 39 no. 3
Type: Research Article
ISSN: 0737-8831

Keywords

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Article
Publication date: 31 July 2020

Susu Nousala, Kim Blanca Galindo, David Romero, Xin Feng and Pedro Aibeo

This research presents an ontological model, to communicate the impact of dynamic preconditions for peri-urban communities. As such, this paper approaches perturbation…

Abstract

Purpose

This research presents an ontological model, to communicate the impact of dynamic preconditions for peri-urban communities. As such, this paper approaches perturbation communities as social-complex-adaptive-systems.

Design/methodology/approach

Previous assessment of dynamic preconditions have typically been based on top-down approaches. Through the lens of social-complex-adaptive and systemic design approaches (requiring a range of different disciplines), this work focuses on providing a broader view towards periurban research. The methodological approach involved academic literature, fieldwork observations, in-depth discussions with community, government, experts and research groups, focusing on a region called “Xochimilco” on the outskirts of Mexico City, a unique pre-Hispanic, Aztec ecosystem. This evolving man made agricultural/ecological structure of island plots, still provides environmental services to Mexico City. This region provides the basis of the research and subsequent ontological model. Ontology, in this instance, refers to the nature of being within a range of constraining dynamic forces relating to resilient behaviors of the current Xochimilco perturbation ecosystem.

Findings

Xochimilco can be considered as a longitudinal phenomenon that contributed to the understanding of observable resilient and precondition elements between the past and present of a living complex-adaptive-system.

Practical implications

The research has provided a better understanding of community resilience through preconditions, contributing towards preparation of environmental change and future urbanization. To this end, the research focused on visualizing key dynamics elements for communities attempting to absorb new urban conditions (being continuously pushed into it).

Originality/value

The outcomes of this research have provided specific systemic, bottom up approaches with ontological modeling to assist with visualizing and understanding intangible dynamic conditions that impact high complex areas of perturbation regions.

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Article
Publication date: 3 April 2019

Yanqiu Xia, Wenyi Zhang, Zhengfeng Cao and Xin Feng

This paper aims to explore the leaf-surface wax as green lubricant additive and compare the tribological properties between coastal and inland leaf-surface waxes of the…

Abstract

Purpose

This paper aims to explore the leaf-surface wax as green lubricant additive and compare the tribological properties between coastal and inland leaf-surface waxes of the same species plant.

Design/methodology/approach

The leaf-surface waxes were extracted from the leaves of Robinia pseudoacacia cv. Idaho and Populus nigra in coastal and inland areas, and then the compositions of the four kinds of leaf-surface waxes were characterized using a gas chromatography–mass spectrometry. The tribological properties of these leaf-surface waxes as lubricant additives in the base oil of synthetic ester (SE) were investigated by an MFT-R4000 reciprocating friction and wear tester. As well as the surface morphologies and chemical compositions of the wear scars were characterized by a scanning electron microscope and time-of-flight secondary ion mass spectrometry, respectively.

Findings

The results indicate that all the leaf-surface waxes as additives can effectively improve the friction reduction and anti-wear performances of SE for steel–aluminum friction pairs. Therein, coastal leaf-surface waxes have better tribological performances than inland leaf-surface waxes, which are attributed to that the leaf-surface waxes extracted from coastal plants can form a better protective film on the worn surface throughout the friction process.

Originality/value

This paper investigated a new kind of environmentally friendly lubricant additive and compared the tribological properties of the leaf-surface wax extracted from coastal and inland plants. The associated conclusions can provide a reference to explore the tribological performances of leaf-surface wax as green lubricant additive.

Details

Industrial Lubrication and Tribology, vol. 71 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 23 March 2010

Yong Han, Nada K. Kakabadse and Andrew Kakabadse

This paper seeks to explore whether the Western concept of servant leadership holds the same meaning in the public sector of the cross‐cultural context of China and to…

Abstract

Purpose

This paper seeks to explore whether the Western concept of servant leadership holds the same meaning in the public sector of the cross‐cultural context of China and to identify whether there is an alternative term in the Chinese language that closely relates to the concept of servant leadership

Design/methodology/approach

An inductive approach is adopted based on critical incident technique, using an open‐ended survey to collect the data.

Findings

It was found that the concept of servant leadership holds parallel meaning in China to that of the West and that the Chinese concept of servant leadership can be described precisely as public servant leadership in the public sector and servant leadership in the non‐public sector. When asked to characterize Chinese servant leadership in the public sector, the study respondents consider six types of servant leadership similar to the West but also three types of Chinese extended servant leadership.

Originality/value

The paper is a first attempt to examine servant leadership in the public sector in China. It not only reports various forms of Chinese servant leadership orientation, but also compares and contrasts various servant leadership forms between China and the West, highlighting research gaps for future research within the context of the People's Republic of China (PRC) and the West.

Details

Journal of Management Development, vol. 29 no. 3
Type: Research Article
ISSN: 0262-1711

Keywords

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Article
Publication date: 1 November 2003

Ke‐Zhang Chen and Xin‐An Feng

In order to represent, analyze, optimize, and manufacture a component made of multi‐heterogeneous materials for high‐tech applications, a computer model of the…

Abstract

In order to represent, analyze, optimize, and manufacture a component made of multi‐heterogeneous materials for high‐tech applications, a computer model of the heterogeneous component needs to be built first. Heterogeneous materials include composite, functionally graded materials, and heterogeneous materials with a periodic microstructure. Current modeling techniques focus only on capturing the geometric information and cannot satisfy the requirements from modeling the components made of multi‐heterogeneous materials. This paper develops a modeling method, which can be implemented by employing the functions of current CAD graphic software and can obtain the model including both the material information (about its microstructures and constituent composition) and the geometry information without the problems arising from too many data.

Details

Integrated Manufacturing Systems, vol. 14 no. 7
Type: Research Article
ISSN: 0957-6061

Keywords

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Article
Publication date: 26 July 2021

Yan Liu, Yanzhen Liu and Guochang Lin

This study aims to investigate the basic mechanical properties of inflatable antenna reflector material under high-low temperatures.

Abstract

Purpose

This study aims to investigate the basic mechanical properties of inflatable antenna reflector material under high-low temperatures.

Design/methodology/approach

Uniaxial tensile tests of Kapton (polyimide) foils were conducted in this paper. Kapton foils with a thickness of 25 µm were used and the strip specimens were manufactured according to the machine direction and the transverse direction of the foils.

Findings

The stress–strain curves of the foils were obtained under ten temperature conditions (−70°C, −40°C, −10°C, 0°C, 20°C, 50°C, 80°C, 110°C, 140°C, 170°C) after uniaxial tensile tests. Generally speaking, such stress–strain curves are highly nonlinear, and Kapton can be classified into some kind of ductile material without obvious yielding point.

Practical implications

The tests results provide a basis for partial coefficients of Kapton foils strength design value, and meanwhile provide basic material data for the extreme temperature field test in orbit for the inflatable antenna structure in the future.

Originality/value

Based on the curve itself and strain energy theory, for the first time the equivalent yielding point was determined and the mechanism of constitutive curve changing with temperature was explained. Based on curves above, tensile strength, elongation at break, equivalent yielding stress, yielding strain and elastic modulus were analyzed and calculated. By analyzing the mechanical parameters above, the fitting formulas with temperature as the variable were given.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 March 2006

Shutian Liu and Yongcun Zhang

In this paper, a homogenization‐based multi‐scale method for predicting the effective thermal conductivity of porous materials with radiation is presented, which considers…

Abstract

In this paper, a homogenization‐based multi‐scale method for predicting the effective thermal conductivity of porous materials with radiation is presented, which considers the effect of geometry and distribution of pores. Using homogenization method to solve the pure conductive problem of porous materials with periodic structure, the effective thermal conductivity without considering radiation is predicted, and a temperature field in a local domain of a unit cell is obtained. This temperature field is taken as the good approximation of the real temperature distribution, and the radiative thermal conductivity is obtained. The effect of the microstructure, the distribution and geometry of pores on heat transfer of porous materials is discussed. It is concluded that the dimension of the pores is an important influence factor on the thermal transfer property of porous materials if radiation is considered. Increasing the pore’s dimension enhances the contribution of radiation to the heat transfer property of porous materials. For porous materials with cylindrical and spherical pores, the radiative thermal conductivity is proportional to pore’s diameter.

Details

Multidiscipline Modeling in Materials and Structures, vol. 2 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

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