Xuhui Wang, Kewei Liu, Kai Wang, Jian Gong, Yanjun Wang and Yajiang Fan
Urban parks play a key role in recreational activities, public health, and ecosystem services in urban areas. Using GIS and Fragstats, this study investigated the spatiotemporal…
Abstract
Urban parks play a key role in recreational activities, public health, and ecosystem services in urban areas. Using GIS and Fragstats, this study investigated the spatiotemporal dynamics of urban parks in Xi'an, China from 1949 to 2015 and the corresponding driving forces. The results show that the number and area of parks in Xi'an increased constantly during this period, especially from 2000 to 2015. Up to 2015, small green spaces, usually adjacent to streets, occupied the largest proportion among all types of parks. Archaeological parks were the largest in total area, but wetland parks were leading in average size of a single park. The density of parks was negatively correlated with their distance to the Clock Tower at the center of Xi'an. The dynamics of urban parks in highly urbanized areas were significantly different from that of their counterparts in suburban areas. Driving forces such as urban planning, urbanization and green space policies, and milestone events in the city's development jointly had a great effect on the distribution of parks in Xi'an. The research outcomes will support the upcoming Green Space Planning of Xi'an and benefit the pursuit of sustainability and human wellbeing.
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Quan Liu, Renchao Wei, Qingshan Feng, Lianshuang Dai, Xiaotong Huo, Dongying Wang, Zhiwen Yang, Bei Wang, Xiuyun Wang, Chong Wang and Yanjun Wang
In this paper, the authors aim to study the relationship between hydrogen embrittlement (HE) susceptibility and cathodic current density applied on the X70 steel girth welds.
Abstract
Purpose
In this paper, the authors aim to study the relationship between hydrogen embrittlement (HE) susceptibility and cathodic current density applied on the X70 steel girth welds.
Design/methodology/approach
The HE susceptibility of X70 steel girth welds were investigated through slow strain rate tensile test and observed and analyzed by optical microscope and scanning electron microscope methods.
Findings
The results show that HE susceptibility of X70 girth weld was basically unchanged with increasing of ion concentration while gradually increased and maintain at a specific value with the increase of cathodic current density. As for same ion content, a dense calcareous deposit layer generated on the sample surface in soil simulation solution with Ca2+ and Mg2+ resulted a decreased HE susceptibility while the porous calcareous deposit layer resulted a increased HE susceptibility.
Originality/value
A logistic regression model was established to describe the correlation between HE index and the cathodic current density.
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Historic districts are faced with inadequate features protection and landscape destruction in the process of accelerating urban construction, urban design focuses on how places…
Abstract
Historic districts are faced with inadequate features protection and landscape destruction in the process of accelerating urban construction, urban design focuses on how places function in addition to how they look, this theory is suitable for the protection of historical districts. At the present stage, the traditional urban design of historical districts has a series of problems, such as uncomprehensive research about characteristics, incomplete workflow and the lack of transformation route from design scheme to implementation, the main reason is that there is a mismatch between the setting goal and planning implementation. Urban design based on “Action planning” has the characteristics of comprehensive research contents, specific implementation plans and complete workflow, it arranges the workflow with four stages, including design preparation, design planning, design implementation and design evaluation, which is a new exploration and attempt to turn traditional blueprint-oriented into action-oriented. Urban design of North Shuncheng Lane Historic Districts in Xi'an city used action planning as a concept and established an framework including “identify development status and problems—construct action target and strategy—determine action projects and specific plans—improve and evaluate the results”, to implement design ideas into practice and to guide the protection of historic districts. Above all, action-oriented planning is considered the key to the development of historic districts.
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The crackdown on the liberal magazine Yanhuang Chunqiu.
Zhiling Ma, Yanjun Qiao, Fei Xie, Xianling Wang and Jing Wang
The purpose of this paper is to evaluate the role of encapsulation temperature on the preparation of silica-encapsulated waterborne aluminium pigments.
Abstract
Purpose
The purpose of this paper is to evaluate the role of encapsulation temperature on the preparation of silica-encapsulated waterborne aluminium pigments.
Design/methodology/approach
The waterborne aluminium pigments were prepared with H2O2 as anchoring agent and siloxane used as precursors in pH = 9.0 medium at different temperatures. The anchorage and compactness of silicon which on aluminium surface were characterized by optical microscopy, scanning electron microscopy and N2 adsorption-desorption. The anticorrosion property was characterized by the volume of produced hydrogen as a function of time.
Findings
The effect of encapsulation temperature on anticorrosion property of aluminium pigments is reflected from the anchorage and the compactness of silica on aluminium surface. Furthermore, when encapsulation temperature is 45-50°C, the silica platelets uniformly anchored on the aluminium surface as a dense film, which show the best anticorrosion property. Lower and higher encapsulation temperatures cause the silica platelets to agglomerate rather than anchor on the aluminium surface, which is unfavourable for the anchorage and the formation of compact silica film. The use of product in waterborne coatings gives a higher glossiness than that of raw material.
Research limitations/implications
Only pH = 9.0 medium was explored, and the other pH medium could result in different optimum temperatures.
Practical implications
The investigation results provide theoretical basis for obtaining excellent waterborne aluminium pigments.
Originality/value
The method of investigating corrosion resistance mechanism of aluminium pigments based on anchorage and compactness is novel.
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Zhiling Ma, Yanjun Qiao, Yajing Wen, Xianling Wang and Jing Wang
This paper aims to evaluate the effect of precursors on the anticorrosion property of silica encapsulated waterborne aluminium pigments (WBAPs).
Abstract
Purpose
This paper aims to evaluate the effect of precursors on the anticorrosion property of silica encapsulated waterborne aluminium pigments (WBAPs).
Design/methodology/approach
The silica encapsulated WBAPs were prepared using different siloxanes as precursors. The anchorage and compactness of silica films on aluminium flakes were characterized by optical microscopy, scanning electron microscopy and N2 adsorption-desorption. The anticorrosion property and glossiness of WBAPs were evaluated.
Findings
The effect of precursors on anticorrosion property of silica encapsulated WBAPs is reflected from the anchorage and the compactness of silica on aluminium flakes surface. Furthermore, the structure of γ-aminopropyl triethoxysilane benefits the anchorage and the compatibility between pigment and acrylic resin. Neither high nor low ratio of tetraethoxysilane/γ-aminopropyl triethoxysilane is favourable to the anchorage and formation of dense silica film on the aluminium flakes surface. To obtain perfect WBAP, the precursors of silica must be carefully selected.
Research limitations/implications
Only four kinds of precursors were used in this work; other precursors could also be studied.
Practical implications
The investigation results provide theoretical basis to obtain excellent WBAPs.
Originality/value
The method to investigate anticorrosion property of WBAPs that is based on the effect of precursors on the performance of silica was novel.
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Tooba Akram, Suresh A.L. RamaKrishnan and Muhammad Naveed
This study aims to diagnose the global key contributors in the stock market manipulation studies during the past four decades.
Abstract
Purpose
This study aims to diagnose the global key contributors in the stock market manipulation studies during the past four decades.
Design/methodology/approach
The database search is based on the terms used in the existing body of knowledge. Using the bibliometric tools and techniques on the Scopus database, the study assessed and analysed the productivity of research studies, as well as the influence of the authors, publications, journals, affiliated institutions and countries.
Findings
This paper finds the USA as the leading country investigating this area, almost capturing 40% of the research studies in finance, moreover, a huge number of co-authors. Financial crises in the late 1990s and 2008 is observed as one of the main reasons for this intriguing research. The Journal of Finance is spotted as the most persuasive journal with the highest cite score and an unprecedented number of citations. The analysis of keywords engendered that most of the stock market manipulation studies are event-based studies. Seminally unique scientometric analysis revealed that the significance of stock market manipulation was mainly captured by event-based studies, insider trading and pump and dump schemes studies. However, much remained untapped to articulate the bridging scope of technology and media with stock market behaviour and manipulations.
Research limitations/implications
The research only includes the Scopus database, however, incorporates 81% relevant study.
Practical implications
This study reckons that technology-based manipulations are emerging themes in this research field which invites the applied research to have productive outcomes.
Originality/value
The intriguing study incorporates a maximum number of the relevant literature and used a comprehensive technique for the selection of dataset in Scopus.
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Yanjun Qin and Jun Wang
Based on commitment system theory and commitment-trust theory, this study aims to reveal the effects of participating teams’ multiple commitments (i.e. synergistic commitments and…
Abstract
Purpose
Based on commitment system theory and commitment-trust theory, this study aims to reveal the effects of participating teams’ multiple commitments (i.e. synergistic commitments and conflicting commitments) on the performance of open innovation projects through the mediating role of trusted knowledge interaction and vigilant knowledge interaction.
Design/methodology/approach
Primary survey data collected from 242 respondents of 47 open innovation projects in the manufacturing industry was used to test eight hypotheses. Correlations between multiple commitments, knowledge interaction and the performance of open innovation projects were investigated.
Findings
The findings reveal that synergistic commitments improve the performance of open innovation projects through enhancing trusted knowledge interaction. Synergistic commitments reduce the level of vigilant knowledge interaction, and the performance of open innovation projects follows an inverted U-shaped relationship with vigilant knowledge interaction. Conflicting commitments negatively moderate the effect of synergistic commitments on trusted knowledge interaction and vigilant knowledge interaction.
Originality/value
The authors extend commitment system theory and commitment-trust theory to open innovation project field. The findings bridge the gaps in isolated and static focus in previous commitment literatures and innovation management literatures, and provide practical guidance for how to better manage the dynamic combination of multiple commitments and knowledge interaction among participating teams in open innovation projects.
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Bo Pu and Yanjun Qiu
We performed a bibiometric analysis on urbanization research based on the 3,058 peer-reviewed articles in the SCI and SSCI database from 1984 to 2013. Our analysis revealed…
Abstract
We performed a bibiometric analysis on urbanization research based on the 3,058 peer-reviewed articles in the SCI and SSCI database from 1984 to 2013. Our analysis revealed document types, scientific outputs, subject categories, major journals and major authors, geographic distribution, highly cited papers and citation networks and temporal trends in keywords burst. Growth of article output has emerged since 1990, and went through two development stages. Environmental sciences, urban studies and ecology came out the most urbanization articles and Landscape and Urban Planning was the most productive journal in urbanization studies. Tothmeresz B was the most prolific author. USA was the most productive country, but Chinese Academy of Sciences was the most high-producing institution. Three streams were identified among the 65 most cited articles in the LCS historiography, and Schueler’s (1994) article has the strongest bursts. A keyword analysis revealed that the “China”, “city” and “globalization” are the research hotspots in the future.
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Yanjun Zhang, Shuangfeng Wang and Zhuming Liu
The purpose of this study is to conduct research on a new kind of division microchannel heat sink (D-MCHS), which can distribute cooling water along the channel-length direction…
Abstract
Purpose
The purpose of this study is to conduct research on a new kind of division microchannel heat sink (D-MCHS), which can distribute cooling water along the channel-length direction. First, the pressure drops in the D-MCHS with different division region numbers were compared. Then, the cooling performance of the D-MCHS with different division region numbers was also comparatively investigated. Finally, the temperature distribution on the bottom surface of the D-MCHS was analyzed.
Design/methodology/approach
First, experiments were conducted to investigate the numerical calculation method. Then, a three-dimensional steady, single-phase, laminar flow and solid-fluid conjugate heat transfer numerical model was used to research the flow and heat transfer characteristics in microchannels.
Findings
The pressure drop in the D-MCHS could be reduced by increasing the number of divided flow regions along the channel-length direction. The bottom average temperature of the D-MCHS could be simultaneously affected by the number of divided flow regions and the water flow rate. The thermal uniformity performance of the D-MCHS could be improved by increasing the number of division flow regions. The number of low-temperature and high-temperature areas on the bottom surface of the D-MCHS is corresponding to the division flow region number.
Originality/value
The D-MCHS exhibited a positive effect on the pressure drop decrease and thermal uniformity improvement. It not only keeps the electronic module working in a secure temperature environment but also consumes less pump power for a lower pressure drop.