Xiaobing Fan, Bingli Pan, Hongyu Liu, Shuang Zhao, Xiaofan Ding, Haoyu Gao, Bing Han and Hongbin Liu
This paper aims to prepare an oil-impregnated porous polytetrafluoroethylene (PTFE) composite with advanced tribological properties using citric acid as a novel pore-forming agent.
Abstract
Purpose
This paper aims to prepare an oil-impregnated porous polytetrafluoroethylene (PTFE) composite with advanced tribological properties using citric acid as a novel pore-forming agent.
Design/methodology/approach
Citric acid (CA) was used to form pores in PTFE, and then oil-impregnated PTFE composites were prepared. The pore-forming efficiency of CA was evaluated. The possible mechanism of lubrication was proposed according to the tribological properties.
Findings
The results show CA is an efficient pore-forming agent and completely removed, and the porosity of the PTFE increases with the increase of the CA content. The oil-impregnated porous PTFE exhibits an excellent tribological performance, an increased wear resistance of 77.29% was realized in comparison with neat PTFE.
Originality/value
This study enhances understanding of the lubrication mechanism of oil-impregnated porous polymers and guides for their tribological applications.
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Nan Li, Muzi Chen, Haoyu Gao, Difang Huang and Xiaoguang Yang
Given the scarcity of data during the early stages of the COVID-19 pandemic in China, the decision-making for non-pharmaceutical policies was mostly based on insufficient…
Abstract
Purpose
Given the scarcity of data during the early stages of the COVID-19 pandemic in China, the decision-making for non-pharmaceutical policies was mostly based on insufficient evidence. The purpose of this study is to assess the effectiveness of these policies, such as lockdown and government subsidies, on rural households and identify policy implications for China and other countries in dealing with pandemics.
Design/methodology/approach
The authors survey 2,408 rural households by telephone from 101 counties across 17 provinces in China during the first stage of the pandemic (March 2020). The authors use the ordered probit model and linear regression model to study the overall impact of policies and then use the quantile regression model and sub-sample regression method to study the heterogeneity of the effects of government policies.
Findings
The authors find that logistics disruption due to lockdown negatively affected rural households. Obstructed logistics is associated with a more significant loss for high-income households, while its impact on the loss expectation of low-income households is more severe. Breeding and other industries such as transport and sales suffer more from logistics than cultivation. The impact of logistics on intensive agricultural entities is more serious than that on professional farms. The government subsidy is more effective at reducing loss for low-income households. Lockdown and government subsidies have shown heterogeneous impacts on rural households.
Practical implications
The overall economic losses experienced by rural households in the early stages of the pandemic are controllable. The government policies of logistics and subsidies should target specific groups.
Originality/value
The authors evaluate the economic impacts of lockdown and government subsidies on rural households and show their heterogeneity among different groups. The authors further demonstrate the policy effectiveness in supporting rural households during the early stages of the pandemic and provide future policy guidance on major public health event.
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Haoyu Gao, Ruixiang Jiang, Wei Liu, Junbo Wang and Chunchi Wu
Using initial public offering (IPO) involuntary delisting data, this chapter examines whether and how motivated institutional investors affect the survivability of IPO firms. The…
Abstract
Using initial public offering (IPO) involuntary delisting data, this chapter examines whether and how motivated institutional investors affect the survivability of IPO firms. The empirical evidence shows that the likelihood of future delisting is much lower for IPOs with more motivated institutional investors. This impact is more pronounced for firms with higher information asymmetry. The motivated institutional investors also facilitate better post-IPO operating performance. The results are consistent with the prediction of the limited attention theory.
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Haoyu Gao, Ruixiang Jiang, Wei Liu, Junbo Wang and Chunchi Wu
This chapter investigates the effect of the geographical distance between institutional investors and firms on managers' financial misconduct. The evidence shows that the…
Abstract
This chapter investigates the effect of the geographical distance between institutional investors and firms on managers' financial misconduct. The evidence shows that the likelihood of committing financial misconduct by management is positively associated with distance. The distance effect is more prominent for firms with higher information asymmetry and more dedicated institutional investors. In line with the balance between risk-taking and benefit extraction from misconduct, the severity of financial misconduct is higher for firms closer to their institutional investors. Results show that geographical proximity can significantly reduce the cost of information production and facilitate monitoring through access to soft information.
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Haoyu Gao, Ruixiang Jiang, Junbo Wang and Xiaoguang Yang
This chapter investigates the cost of public debt for firms using a comprehensive sample consisting of 17,368 industrial bond issues from 1970 to 2011. The empirical evidence…
Abstract
This chapter investigates the cost of public debt for firms using a comprehensive sample consisting of 17,368 industrial bond issues from 1970 to 2011. The empirical evidence shows that yield spreads for seasoned bond issues are significantly lower than those for initial bond issues. This seasoning effect is robust across different sample periods, subsamples, and model specifications. On average, the yield spreads for seasoned bond issues are around 50 bps lower than those for initial bond issues. This difference cannot be explained by other bond and firm characteristics. The seasoning effect is more pronounced for firms with higher levels of uncertainty, lower information disclosure quality, and longer time intervals between the first and subsequent issues. Our empirical findings provide supportive evidence for the extant theories that aim to rationalize the information role in determining the cost of capital.
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Haoyu Gao, Ruixiang Jiang, Chunchi Wu and Xiaoguang Yang
This chapter presents evidence of persistence in pricing new corporate bond issues. Both transition matrix and regression analyses show that cross-sectional differences in the…
Abstract
This chapter presents evidence of persistence in pricing new corporate bond issues. Both transition matrix and regression analyses show that cross-sectional differences in the yields of initial public bond offerings across issuers persist over time, and the persistence effect is stronger for firms with no rating changes, less frequent bond issuance, and higher information asymmetry. Our findings support the hypothesis of the “ride on past” behavior and confirm the value of information production accumulated from the past bond issuances for the pricing of newly issued bonds.
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Yanli Feng, Ke Zhang, Haoyu Li and Jingyu Wang
Due to dynamic model is the basis of realizing various robot control functions, and it determines the robot control performance to a large extent, this paper aims to improve the…
Abstract
Purpose
Due to dynamic model is the basis of realizing various robot control functions, and it determines the robot control performance to a large extent, this paper aims to improve the accuracy of dynamic model for n-Degree of Freedom (DOF) serial robot.
Design/methodology/approach
This paper exploits a combination of the link dynamical system and the friction model to create robot dynamic behaviors. A practical approach to identify the nonlinear joint friction parameters including the slip properties in sliding phase and the stick characteristics in presliding phase is presented. Afterward, an adaptive variable-step moving average method is proposed to effectively reduce the noise impact on the collected data. Furthermore, a radial basis function neural network-based friction estimator for varying loads is trained to compensate the nonlinear effects of load on friction during robot joint moving.
Findings
Experiment validations are carried out on all the joints of a 6-DOF industrial robot. The experimental results of joint torque estimation demonstrate that the proposed strategy significantly improves the accuracy of the robot dynamic model, and the prediction effect of the proposed method is better than that of existing methods.
Originality/value
The proposed method extends the robot dynamic model with friction compensation, which includes the nonlinear effects of joint stick motion, joint sliding motion and load attached to the end-effector.
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Fawad Ahmed, Wei Hu, Ahmad Arslan and Haoyu Huang
Human resource management (HRM) practices must take an ambidextrous approach because of changing work environments and challenges. Ambidextrous practices in HRM fall in the domain…
Abstract
Purpose
Human resource management (HRM) practices must take an ambidextrous approach because of changing work environments and challenges. Ambidextrous practices in HRM fall in the domain of developing expertise for complex environments and reducing ambiguities in present turbulent times. Dual-oriented ambidextrous human resource practices (AHRP) can promote employee innovation performance. Drawing on social exchange theory to explore the impact of AHRP on employee innovation performance, this paper examines the mediating role of inclusive leadership style.
Design/methodology/approach
Data were collected through a questionnaire from employees of three Fortune 500 Chinese companies from the telecom, electronics and automotive sectors with temporal separation in two waves. The final sample constituted 276 useable responses.
Findings
Results indicate that ambidextrous HR practices have a significant impact on innovation performance, and an inclusive leadership style mediates this relationship, together explaining a 27.8% variance.
Originality/value
This paper examines the effect of dual-oriented AHRPs in the emerging markets context as a guide to best practices for managers to employ ambidexterity in HRM to enhance employees' innovation performance by enhancing both commitment as well as cooperation simultaneously.
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Haitao Wang, Tao Guo and Haoyu Sun
This paper aims to focus on establishing the bond-slip constitutive relation of mortar anchor under high loading rates by the dynamic pull-out test.
Abstract
Purpose
This paper aims to focus on establishing the bond-slip constitutive relation of mortar anchor under high loading rates by the dynamic pull-out test.
Design/methodology/approach
Self-made specimens were made for the dynamic pull-out test to explore the bond performance of mortar anchor, and the bond-slip constitutive relation of mortar anchor under high loading rates was established according to the analysis of test data.
Findings
During the loading process, the position of the peak bond stress was observed to translate to the free end. The bearing capacity of the mortar anchor was enhanced to some extent due to the increase of the loading rate.
Originality/value
The bond-slip constitutive relation of mortar anchor under high loading rates was established with the introduction of the position function and dynamic-load expanded coefficient.
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Chao Liu, Mingyang Yang, Haoyu Han and Wenping Yue
To study fracture characteristics of jointed rock masses under blasting load, the RFPA2D analysis software for dynamic fracture of rocks based on the finite element method and…
Abstract
Purpose
To study fracture characteristics of jointed rock masses under blasting load, the RFPA2D analysis software for dynamic fracture of rocks based on the finite element method and statistical damage theory was used.
Design/methodology/approach
On this basis, this research simulated the fracture process of rock masses in blasting with different joint geometrical characteristics and mainly analysed the influences of distance from joints to blasting holes, the length of joints, the number of joints and joint angle on fracture of rock masses.
Findings
The calculation results show that with the constant increase of the distance from joints to blasting holes, the influences of joints on blasting effects of rock masses gradually reduced. Rock masses with long joints experienced more serious damages than those with short joints. Damages obviously increased with the changing from rock masses without joints to rock masses with joints, and when there were three joints, the further increase of the number of joints had unobvious changes on blasting effects of rock masses. Joints showed significant guidance effect on the propagation of cracks in blasting: promoting propagation of main vertical cracks deflecting to the ends of joints.
Originality/value
The research results are expected to provide some theoretical bases in practical application of engineering blasting.