Xiaoyang Zhao, Xia Mao and Yuxiu Lu
This study aims to investigate the factors affecting urban economic development in emerging economic market countries and to provide a new research perspective on urban skyscraper…
Abstract
Purpose
This study aims to investigate the factors affecting urban economic development in emerging economic market countries and to provide a new research perspective on urban skyscraper construction.
Design/methodology/approach
An empirical analysis based on a difference-in-differences (DID) model is conducted using data of urban data in China that expand into developed markets from 2003 to 2018.
Findings
The results of the spatial heterogeneity test indicate that the construction of skyscrapers has a significant promotional effect on the eastern city's economy. In contrast, it has a significant inhibitory effect in the central and western regions. Further findings demonstrate that the construction of skyscrapers can influence urban economic development by promoting industrial agglomeration, especially when the transmission effect of the diversified accumulation of tertiary industry is more prominent. The expansion analysis shows that skyscrapers have increased the level of trade in the city, and the impact on trade has an optimal height.
Research limitations/implications
This paper focuses on the economic and trade effects of skyscrapers, and the optimal height of skyscrapers needs to be discussed in more depth, which is also the next problem the researchers need to study.
Practical implications
The government should attach importance to and promote the construction of urban skyscrapers, and do a good job in overall planning and design. The city should formulate preferential policies in land, taxation, finance, system and other aspects to increase support for urban skyscraper construction and promote local economic development.
Originality/value
This study focuses on the impact of urban skyscraper construction on the economic and trade development of cities in developing countries, which not only complements the relevant research on the economic effects of urban skyscraper construction, but also helps to provide reference for the sustainable development of urbanization in many developing countries.
Details
Keywords
Yesen Zhu, Taoyong Hu, Yujie Li, Junhua Hao, Bin Han and Quan Yuan
The aim of this paper is to construct a device that simulated the seawater splash zone, dynamic waterline zone (splash zone) and full immersion zone. Localized corrosion of 2A12…
Abstract
Purpose
The aim of this paper is to construct a device that simulated the seawater splash zone, dynamic waterline zone (splash zone) and full immersion zone. Localized corrosion of 2A12 aluminum alloy long-scale specimen was studied.
Design/methodology/approach
Corrosion morphologies before and after the corrosion product removal were used to identify corrosion intensity at full seawater immersion zone, dynamic waterline zone (splash zone) and atmospheric zone. The average depth and diameter of corrosion pits in the three zones were evaluated by three-dimensional optical microscopy. The impact of wetting time of the atmospheric zone on the localized corrosion was investigated.
Findings
Corrosion pits were observed on the surface on day 4 for the wetted atmospheric zone (Case 1), and on the surface on day 8 for the alternant wet/dry atmospheric zone (Case 2). The corrosion product layer on the surface for Case 1 was partially broken down while the layer on the surface for Case 2 was intact. Average pitting depth and pitting diameters for Case 1 were more serious than that for Case 2.
Originality/value
The above findings revealed that the humidity of the atmospheric zone had great impact on the localized corrosion of aluminum alloy at the seawater splash zone.
Details
Keywords
This study examines the stock market efficiency in China to offer trading strategy guidance to investors and efficiency evaluation insight to policymakers.
Abstract
Purpose
This study examines the stock market efficiency in China to offer trading strategy guidance to investors and efficiency evaluation insight to policymakers.
Design/methodology/approach
This study examines the stock market efficiency in China with a new combined liquidity trading strategy by blending technical analysis into a liquidity buy-and-hold strategy.
Findings
Our results show that the combined strategy generates significant excess returns in the whole sample period, suggesting that the Chinese stock market is not consistent with the weak form efficient hypothesis. In addition, the combined strategy yields more significant risk-adjusted excess returns after the 2004 split-share reform, indicating the stock market efficiency in China does not exhibit a distinct upgrade after the reform. Our further test results reinforce the main conclusions after taking transaction costs, market states, short-selling reform and other issues into consideration.
Originality/value
Our study contributes to the literature in two ways: First, we shed light on the mixed documented results about the market efficiency form in China. Second, we contribute to the mixed relation between the 2004 split-share reform and market efficiency in China.
Details
Keywords
Wei Zhang and Jianqin Mao
This paper proposes a robust modeling method of a giant magnetostrictive actuator which has a rate‐dependent nonlinear property.
Abstract
Purpose
This paper proposes a robust modeling method of a giant magnetostrictive actuator which has a rate‐dependent nonlinear property.
Design/methodology/approach
It is known in statistics that the Least Wilcoxon learning method developed using Wilcoxon norm is robust against outliers. Thus, it is used in the paper to determine the consequence parameters of the fuzzy rules to reduce the sensitiveness to the outliers in the input‐output data. The proposed method partitions the input space adaptively according to the distribution of samples and the partition is irrelative to the dimension of the input data set.
Findings
The proposed modeling method can effectively construct a unique dynamic model that describes the rate‐dependent hysteresis in a given frequency range with respect to different single‐frequency and multi‐frequency input signals no matter whether there exist outliers in the training set or not. Simulation results demonstrate that the proposed method is effective and insensitive against the outliers.
Originality/value
The main contributions of this paper are: first, an intelligent modeling method is proposed to deal with the rate‐dependent hysteresis presented in the giant magnetostrictive actuator and the modeling precision can fulfill the requirement of engineering, such as the online modeling issue in the active vibration control; and second, the proposed method can handle the outliers in the input‐output data effectively.
Details
Keywords
Yao Chen, Ruijun Liang, Wenfeng Ran and Weifang Chen
In gearbox fault diagnosis, identifying the fault type and severity simultaneously, as well as the compound fault containing multiple faults, is necessary.
Abstract
Purpose
In gearbox fault diagnosis, identifying the fault type and severity simultaneously, as well as the compound fault containing multiple faults, is necessary.
Design/methodology/approach
To diagnose multiple faults simultaneously, this paper proposes a multichannel and multi-task convolutional neural network (MCMT-CNN) model.
Findings
Experiments were conducted on a bearing dataset containing different fault types and severities and a gearbox compound fault dataset. The experimental results show that MCMT-CNN can effectively extract features of different tasks from vibration signals, with a diagnosis accuracy of more than 97%.
Originality/value
Vibration signals at different positions and in different directions are taken as the MC inputs to ensure the integrity of the fault features. Fault labels are established to retain and distinguish the unique features of different tasks. In MCMT-CNN, multiple task branches can connect and share all neurons in the hidden layer, thus enabling multiple tasks to share information.
Details
Keywords
Purpose – This chapter explores ways in which urban women in China balance work and family demands, as the state's protective and welfare functions in post-Mao reform are…
Abstract
Purpose – This chapter explores ways in which urban women in China balance work and family demands, as the state's protective and welfare functions in post-Mao reform are increasingly being replaced by market forces, and the chapter examines how urban women's enactment of work and family roles are shaped by changing workplaces as well as by their personal and family circumstances. The purpose is to understand the impact of marketization on gender configuration through the lens of the work-family nexus.
Research design – Data come from in-depth interviews conducted between 2005 and 2007 with 115 married women in four large cities. For analytical purposes, the informants were divided into three groups: stay-at-home moms, family-orientated working women, and work/career-oriented women.
Findings – Although market reform may create opportunities for some women to enhance their personal lives, as a consequence of workers' loss of the safety net and welfare benefits, the neglect of women's reproductive work, and the commercialization of child care and child education, it has generated, for many women, much role conflict between work and family. Work/career-oriented women are able to actively engage in market activities precisely because they are protected still by the state, can afford commercial services of domestic tasks, or have strong support from their extended families.
Originality/value – Women's varying role orientations reflect more their strategies of coping with structural changes than their mere adherence to certain gender ideologies.
Social implications – The chapter calls for curbing unbridled market forces and restoring public services so as to create a family/women-friendly work and social environment.
Details
Keywords
Yida Liu, Jie Zhao, Xiaoyu Yang, Yanhong Gu and Zihao Yang
The purpose of this paper is to improve the corrosion resistance of the 6061-Al alloy as the battery pack material for electric vehicles, and the nano-SiC/MAO composite coating…
Abstract
Purpose
The purpose of this paper is to improve the corrosion resistance of the 6061-Al alloy as the battery pack material for electric vehicles, and the nano-SiC/MAO composite coating was prepared.
Design/methodology/approach
The corrosion resistance of coatings was evaluated by the global electrochemical test, and the local electrochemical impedance spectroscopy (LEIS) was used to study the local corrosion mechanism. The laser confocal microscope, scanning electron microscope and X-ray diffractometer (XRD) were used to characterise coatings.
Findings
Results showed that the impedance of nano-SiC/MAO coating was 1–2 times higher than MAO coating, and the main corrosion product was Al(OH)3. LEIS results showed that the impedance of the nano-SiC/MAO coating was two times higher than the MAO coating. The defective SiC/Micro-arc oxidation coating still had high corrosion resistance compared to the MAO coating.
Originality/value
The physical model of the local corrosion mechanism for SiC/MAO composite coating in “cavity-fracture collapse” mode was proposed.
Details
Keywords
Xiaowen Chen, Wanlin Xie, Song Tang, Meng Zhang, Hao Song, Qingzheng Ran and Defen Zhang
The purpose of this study is to examine the impact of MoS2 on the microstructure and characteristics of micro-arc oxidized (MAO) ceramic coatings created on ZK60 magnesium alloy…
Abstract
Purpose
The purpose of this study is to examine the impact of MoS2 on the microstructure and characteristics of micro-arc oxidized (MAO) ceramic coatings created on ZK60 magnesium alloy through the addition of varying concentrations of MoS2 particles to the electrolyte, aiming to enhance the corrosion resistance of magnesium alloy.
Design/methodology/approach
The surface morphology, roughness and phase composition of the coatings were analyzed using scanning electron microscopy, a hand-held roughness tester and an X-ray diffractometer, respectively, and the corrosion resistance of the MAO coatings prepared by the addition of different contents of MoS2 particles was tested and analyzed using an electrochemical workstation.
Findings
The results demonstrate that MoS2/MgO composite coatings have been successfully prepared on the surface of magnesium alloys through micro-arc oxidation. Furthermore, the corrosion resistance of the ZK60 magnesium alloy prepared with the addition of 1.0 g/L MoS2 was the best compared to the other samples.
Originality/value
MoS2 particles were able to penetrate the coatings successfully during the micro-arc oxidation process, acting as a barrier in the micropores to prevent the corrosion medium from touching the surface, thus improving the corrosion resistance of the sample. The electrochemical workstation was used to study the corrosion resistance of the MoS2/MAO coating on the ZK60 magnesium alloy.
Details
Keywords
Qiang Cao, Nanwei Hu and Lizhong Hao
The purpose of this paper is to examine whether client industry importance affects auditor independence.
Abstract
Purpose
The purpose of this paper is to examine whether client industry importance affects auditor independence.
Design/methodology/approach
This study analyzes audit firm merger data from China Stock Market and Accounting Research and uses a difference-in-difference model to find whether client industry importance is associated with auditor independence. This study uses discretionary accruals and propensity to issue modified audit opinions as proxies for auditor independence.
Findings
Results show that the greater the decline in client industry importance, the more significant the increase in auditor independence. In addition, the magnitude of decline in client overall importance is also positively associated with the extent of increase in auditor independence; however, this result disappears after controlling for client industry importance.
Research limitations/implications
The authors acknowledge that this study has limitations. First, audit firm mergers provide a unique research setting. However, the findings of this study in such setting may not be generalizable to other situations. Second, this study has a limited sample size because of data availability, which could impact the robustness of the results.
Originality/value
Results from this study are important because investors and regulators have increasing concerns over auditor independence since the Enron scandal. To the best of the authors’ knowledge, this study is the first to examine the impact of client industry importance on auditor independence and in a unique setting of audit firm merger to separate auditor independence from auditor competence, and hence controlling for self-selection bias. Results of this study provide evidence that client industry importance has significant influence over auditor independence.
Details
Keywords
Aysun Aksit, Nurhan Onar, Bengi Kutlu, Evren Sergin and Ismail Yakin
The purpose of this paper is to develop the flame retardancy properties of cotton fabrics with treatment of phosphorus and nitrogen containing silane-based nanosol by sol-gel…
Abstract
Purpose
The purpose of this paper is to develop the flame retardancy properties of cotton fabrics with treatment of phosphorus and nitrogen containing silane-based nanosol by sol-gel process.
Design/methodology/approach
Nanosols containing tetraethoxysilane or (3-aminopropyl) triethoxysilane as precursors, (3-glycidyloxypropyl) trimethoxysilane as cross-linking agent and guanidine phosphate monobasic as flame retarding agent were impregnated on cotton fabrics. Flame retardancy properties of the fabric samples were determined by limited flame spread test and limited oxygen index (LOI) test. In addition, microstructural and surface morphological properties of the fabric samples were characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscope.
Findings
Depending on the limited flame spread test, the authors show that the coated fabric samples gain flame retardancy properties and the LOI value of the samples increased as to 45.7 per cent by the synergistic effect of phosphorus-nitrogen-silicon.
Originality/value
There have some studies in flame retardancy behaviour of textiles. In this study, flame retardant cotton fabric with very low weight in grams was improved by sol-gel process. Moreover, ecological process was provided thanks to using halogen-free flame retardant.