Ting Xie, Junjie Lai and Huaping Yang
This paper aims to simulate the effect of counterface roughness on the friction transfer and wear of the polymer material sliding against steel.
Abstract
Purpose
This paper aims to simulate the effect of counterface roughness on the friction transfer and wear of the polymer material sliding against steel.
Design/methodology/approach
The dynamic process of friction transfer and wear of polytetrafluoroethylene (PTFE) sliding against steel 45 was simulated by the software of particle flow code in two dimensions and a discrete element method. The effect of the counterface roughness was considered in the simulation. The definitions of the transferred particle and worn particle were given.
Findings
The simulation results showed that a transferred particle layer was formed on the surface of steel 45 during friction. The wear rate of PTFE can be effectively reduced by the formation of the transferred particle layer. The formation and stability of this particle layer is certainly affected by the counterface roughness (Rz). In this paper, the transferred particle numbers increased with Rz increase. And so did the worn particle numbers. However, there was little effect of Rz on the wear rate of PTFE.
Originality/value
The dynamic process of the friction transfer and wear of the PTFE/ steel 45 friction pair was reproduced at the micro-level. Then, the transfer and wear were quantitatively exhibited. The relations between the transfer or wear and counterface roughness was simulated and discussed. It will be meaningful for the optimization and effective control of friction and wear of polymer/metal sliding system.
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Zhimin Cao, Wenjun Zong, Junjie Zhang, Chunlei He, Jiaohu Huang, Wei Liu and Zhiyong Wei
This paper aims to reveal the tribochemical reaction mechanism on the nano-cutting interface between HMX crystal and diamond tool.
Abstract
Purpose
This paper aims to reveal the tribochemical reaction mechanism on the nano-cutting interface between HMX crystal and diamond tool.
Design/methodology/approach
Molecular dynamics simulation of HMX crystal nano-cutting by the reactive force field is carried out in this paper. The affinity of activated atoms and friction damage at the different interface have been well identified by comparing two cutting systems with diamond tool or indenter. The analyses of reaction kinetics, decomposition products and reaction pathways are performed to reveal the underlying atomistic origins of tribocatalytic reaction on the nano-cutting interface.
Findings
The HMX crystals only undergo damage and removal in the indenter cutting, while they appear to accelerate thermal decomposition in the diamond cutting. the C-O affinity is proved to be the intrinsic reason of the tribocatalytic reaction of the HMX-diamond cutting system. The reaction activation energy of the HMX crystals in the diamond cutting system is lower, resulting in a rapid increase in the decomposition degree. The free O atoms can induce the asymmetric ring-opening mode and change the decomposition pathways, which is the underlying atomistic origins of the thermal stability of the HMX-diamond cutting system.
Originality/value
This paper describes a method for analyzing the tribochemical behavior of HMX and diamond, which is beneficial to study the thermal stability in the nano-cutting of HMX.
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Junjie Zhou, Rajiv Kishore, Meiyun Zuo, Ruochen Liao and Xiao Tang
As older adults are increasingly active in virtual communities (VCs), these platforms for knowledge exchange present opportunities for companies to use elder human capital. The…
Abstract
Purpose
As older adults are increasingly active in virtual communities (VCs), these platforms for knowledge exchange present opportunities for companies to use elder human capital. The purpose of this study is to understand the antecedent factors that motivate older adults’ knowledge contribution and knowledge seeking (KS) behaviors in VCs.
Design/methodology/approach
Rooted in socio-emotional selectivity and social cognitive theories, this study included five key variables and developed models for older adults’ knowledge contributing (KC)/KS behaviors. This paper tested the hypotheses using data from a sample of 204 older adults in 3 VCs in China.
Findings
The results provide support for most of the hypotheses and show that while other members’ participation (MP) acts as a substitute for meaning in life and attitude toward aging, it acts as a complement for outcome expectations (OE) focused on others and OE focused on oneself in their impacts on KC/KS activities.
Practical implications
The study provides practical insights for developing elder human resources via VCs to avoid knowledge loss.
Originality/value
This study described older adults’ unique characteristics when modeling their information and communication technologies-related behaviors and built two models to explain their KC/KS behaviors. It confirmed that the same factor has different levels of impact on older adults’ KC/KS behaviors in VCs. In addition, it confirmed and reinforced the complementary and substitutive effects of other MP as an environmental factor on these behaviors.
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Lin Kang, Jie Wang, Junjie Chen and Di Yang
Since the performance of vehicular users and cellular users (CUE) in Vehicular networks is highly affected by the allocated resources to them. The purpose of this paper is to…
Abstract
Purpose
Since the performance of vehicular users and cellular users (CUE) in Vehicular networks is highly affected by the allocated resources to them. The purpose of this paper is to investigate the resource allocation for vehicular communications when multiple V2V links and a V2I link share spectrum with CUE in uplink communication under different Quality of Service (QoS).
Design/methodology/approach
An optimization model to maximize the V2I capacity is established based on slowly varying large-scale fading channel information. Multiple V2V links are clustered based on sparrow search algorithm (SSA) to reduce interference. Then, a weighted tripartite graph is constructed by jointly optimizing the power of CUE, V2I and V2V clusters. Finally, spectrum resources are allocated based on a weighted 3D matching algorithm.
Findings
The performance of the proposed algorithm is tested. Simulation results show that the proposed algorithm can maximize the channel capacity of V2I while ensuring the reliability of V2V and the quality of service of CUE.
Originality/value
There is a lack of research on resource allocation algorithms of CUE, V2I and multiple V2V in different QoS. To solve the problem, one new resource allocation algorithm is proposed in this paper. Firstly, multiple V2V links are clustered using SSA to reduce interference. Secondly, the power allocation of CUE, V2I and V2V is jointly optimized. Finally, the weighted 3D matching algorithm is used to allocate spectrum resources.
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Hualong Yang, Zhiying Cheng and Junjie Zhou
The online profile picture of a doctor serves as a pivotal source of visual information, playing a key role in shaping the doctor’s professionalism in the online health market…
Abstract
Purpose
The online profile picture of a doctor serves as a pivotal source of visual information, playing a key role in shaping the doctor’s professionalism in the online health market. Doctors can strategically curate the elements of their online profile pictures, such as attire and background, to either reinforce a formal image or craft a casual image, thereby influencing patients’ doctor choices. Despite this, the relative effectiveness of formal or casual images in swaying patient choices remains unclear. This study endeavors to bridge this knowledge gap.
Design/methodology/approach
This study tested the influence of a doctor’s attire and background in their profile picture on patient decision-making, with a focus on discerning variations in impact among patient groups differentiated by the severity of their illnesses (i.e. high-severity versus low-severity conditions). We formulated four hypotheses and tested them through an econometric analysis and a controlled laboratory experiment.
Findings
The empirical findings reveal that doctors’ formal profile pictures, characterized by formal attire and backgrounds, exert a more pronounced influence on patient choices than casual images. The severity of a patient’s illness positively moderated the relationship between formal images and patient choices.
Originality/value
These insights make a significant contribution to the understanding of patient behavior in selecting doctors within the online health market. Furthermore, they offer valuable guidance for doctors in optimizing their online profile presentation to better align with patient preferences and expectations.
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Junjie Gong, Zhixiang Li, Qingqing Lin and Kunhong Hu
This study aims to explore the synthesis and tribological performances of di-n-octyl sebacate (DOS) synthesized with spherical nano-MoS2/sericite (SMS) and carboxylated SMS (CSMS…
Abstract
Purpose
This study aims to explore the synthesis and tribological performances of di-n-octyl sebacate (DOS) synthesized with spherical nano-MoS2/sericite (SMS) and carboxylated SMS (CSMS) as catalysts.
Design/methodology/approach
SMS and CSMS were used as esterification catalysts to synthesize DOS from sebacic acid and n-octanol. The two catalysts were in situ dispersed in the synthesized DOS after the reaction to form suspensions. The tribological performances of the two suspensions after 20 days of storage were studied.
Findings
CSMS was more stably dispersed in DOS than SMS, and they reduced friction by 55.6% and 22.2% and wear by 51.3% and 56.5%, respectively. Such results were mainly caused by the COOH on CSMS, which was more conducive to improving the dispersion and friction reduction of CSMS than wear resistance. Another possible reason was the difference between the dispersion amounts of CSMS and SMS in DOS. The sericite of SMS was converted into SiO2 to enhance wear resistance, while that of CSMS only partially generated SiO2, and the rest still remained on the surface to reduce friction.
Originality/value
This work provides a more effective SMS catalytical way for DOS synthesis than the traditional inorganic acid catalytical method. SMS does not need to be separated after reaction and can be dispersed directly in DOS as a lubricant additive. Replacing SMS with CSMS can produce a more stable suspension and reduce friction significantly. This work combined the advantages of surface carboxylation modification and in situ catalytic dispersion and provided alternatives for the synthesis of DOS and the dispersion of MoS2-based lubricant additives.
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Lili Shang, Junjie Zhou and Meiyun Zuo
Social media greatly enhances public access to health information and thus attracts older adults who tend to attach more importance to their health. This study aims to identify…
Abstract
Purpose
Social media greatly enhances public access to health information and thus attracts older adults who tend to attach more importance to their health. This study aims to identify the factors that contribute to the likelihood of older adults' health information sharing on social media.
Design/methodology/approach
By drawing on health belief (HBM) and elaboration likelihood models (ELM), a novel conceptual model integrating older adults' health belief and information processing is established to uncover the factors. Online survey data from 290 Chinese older adult users of WeChat, the most popular social media platform in China, were collected to test the research model.
Findings
As health belief-related variables, perceived susceptibility is positively associated with health information-sharing intention (HISI), while perceived severity negatively influences HISI, which is contrary to prior findings. For information processing, the positive impacts of argument quality and source credibility on HISI are fully mediated by perceived usefulness.
Originality/value
This study is one of the first studies to explore the initiative use of information and communication technology among older adults. The new theoretical perspective proposed herein considers health belief and information processing perspectives in a complementary manner and can facilitate an overall analysis of the factors influencing older adults' HISI in a social media context. This study also furthers understandings of the ELM and expands the theory of HBM to take the age of decision makers into account.
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This study aims to understand the epistemic foundation of the classification applied in the first Chinese library catalogue, the Seven Epitomes (Qilue).
Abstract
Purpose
This study aims to understand the epistemic foundation of the classification applied in the first Chinese library catalogue, the Seven Epitomes (Qilue).
Design/methodology/approach
Originating from a theoretical stance that situates knowledge organization in its social context, the study applies a multifaceted framework pertaining to five categories of textual data: the Seven Epitomes; biographical information about the classificationist Liu Xin; and the relevant intellectual, political, and technological history.
Findings
The study discovers seven principles contributing to the epistemic foundation of the catalogue's classification: the Han imperial library collection imposed as the literary warrant; government functions considered for structuring texts; classicist morality determining the main classificatory structure; knowledge perceived and organized as a unity; objects, rather than subjects, of concern affecting categories at the main class level; correlative thinking connecting all text categories to a supreme knowledge embodied by the Six Classics; and classicist moral values resulting in both vertical and horizontal hierarchies among categories as well as texts.
Research limitations/implications
A major limitation of the study is its focus on the main classes, with limited attention to subclasses. Future research can extend the analysis to examine subclasses of the same scheme. Findings from these studies may lead to a comparison between the epistemic approach in the target classification and the analytic one common in today's bibliographic classification.
Originality/value
The study is the first to examine in depth the epistemic foundation of traditional Chinese bibliographic classification, anchoring the classification in its appropriate social and historical context.
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There are a large number of interdependent risk factors in complex project. Risk response strategy without considering risk correlation cannot achieve good risk response…
Abstract
Purpose
There are a large number of interdependent risk factors in complex project. Risk response strategy without considering risk correlation cannot achieve good risk response. Therefore, the purpose of this paper is to propose a risk response strategy selection model considering risk correlation based on the grey K-shell algorithm.
Design/methodology/approach
This paper mainly focuses on the measurement of two aspects of risk factors. One is the ability of the risk factors to influence other risk factors, another is the degree affected by other risk factors. Both of the above are measured by the grey K-shell algorithm improved in this paper, and the weights of these are used for the constructing of risk response strategy selection model.
Findings
The risk response strategy considering risk relevance is more effective than the risk response strategy without considering risk relevance. Also, results indicate that as the risk response budget increases the risk response effect also increases, and the increasing trend is weakens. The relative gap between the effect of response strategies considering risk relevance and the strategy without considering risk relevance increases first and, then, decreases with the increase of budget.
Originality/value
The results of this paper demonstrate that the risk response strategy considering risk relevance is more effective than not considering risk relevance. The approach presented in this paper can guide project managers’ risk decisions and may also help to find the best risk response budget.
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Qingyu Shi, Jingyu Yu, Lifei Zhang, Jingfeng Wang and Guowei Cheng
The construction industry has experienced an irreversible digital transformation to smart construction. Many countries have published supporting policies to encourage the…
Abstract
Purpose
The construction industry has experienced an irreversible digital transformation to smart construction. Many countries have published supporting policies to encourage the development of smart construction. However, there is no universally valid approach. This paper thus aims to evaluate smart construction policies issued by 24 pilot cities in China and identify applicable policy tools and their impact.
Design/methodology/approach
This paper collected 33 governmental documents on smart construction through the official websites in China. Different policy tools were classified into supply-side, demand-side and environment-side categories. The supporting policies of smart construction development in pilot cities were quantitatively evaluated by using a policy modeling consistency index (PMC-index) model.
Findings
Supply-type and environment-type policy instruments were used more frequently than demand-type policies in 24 pilot cities. Most of the 24 pilot cities had an evaluation of PMC-index over 8, realizing the consistency of smart construction policies. Eight pilot cities had an evaluation of PMC-index of 6–7.99, realizing acceptable consistency. Only Foshan City has an evaluation of PMC-index below 4, which may reflect a poor consistency of policy implementation. The paper proposes consistencies of smart construction policies of 24 pilot cities and valid policy instruments, including the presale of commercial residential buildings, additional bonus points in the tendering process and cooperating with multiple departments when promoting smart construction.
Originality/value
This paper contributes to expanding policy evaluation studies in the smart construction field and provides concrete suggestions for policymakers to formulate more effective and specific policies and strategies for the development of smart construction.