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1 – 10 of 471Yuan-yan Hu, Peng Wang, Xin-qiang Wang and Tian-qiang Hu
Despite concerns about the effect of internet addiction, little is known about how psychological suzhi impacts the internet addiction of college students. This paper aims to…
Abstract
Purpose
Despite concerns about the effect of internet addiction, little is known about how psychological suzhi impacts the internet addiction of college students. This paper aims to investigate the relationship between psychological suzhi and internet addiction among college students.
Design/methodology/approach
Using the college student psychological suzhi scale and internet addiction test, 2,070 college students from 11 universities in North China, East China, South China and Southwest China were tested.
Findings
The detection rate of internet addiction in this college sample of students was 18.8%. There was a significant negative correlation between students’ psychological suzhi and internet addiction (r = −0.408, p < 0.01). Hierarchical regression analysis showed that adaptability and individuality in psychological suzhi significantly negatively predicted college students’ internet addiction tendency (p < 0.001).
Originality/value
This study is the first to show a relationship between psychological suzhi and internet addiction in college students. In detail, the adaptability and individuality of college students’ psychological suzhi are protective factors related to internet addiction. The results also suggested that the authors can prevent and intervene in internet addiction by modifying college students’ adaptability and individuality.
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Jiacheng Zhou, Jinglin Shi, Dongfan Yin, Lei Xu, Fuwen Zhang, Zhigang Wang, Qiang Hu and Huijun He
This study aims to investigate the impact of indium (In) content on the thermal properties, microstructure and mechanical properties of Sn-3Ag-3Sb-xIn (x = 0, 1, 2, 3, 4, 5 Wt.%…
Abstract
Purpose
This study aims to investigate the impact of indium (In) content on the thermal properties, microstructure and mechanical properties of Sn-3Ag-3Sb-xIn (x = 0, 1, 2, 3, 4, 5 Wt.%) solders to enhance the performance of tin-based solder under demanding conditions and to meet the urgent need for high-reliability microelectronic interconnection materials in emerging sectors such as automotive intelligent technology, 5G communication technology and high-performance computing.
Design/methodology/approach
In this study, Sn-3Ag-3Sb-xIn solder alloys were prepared. The thermal properties of the solder alloys were characterised by differential scanning calorimetry. Subsequently, optical microscopy, scanning electron microscopy, X-ray diffraction and an electron probe X-ray microanalyser were used to analyse the influence of the In content on the microstructure of the solder. The mechanical properties of solder alloys were determined through tensile testing.
Findings
As the In content increased, the melting temperature of the Sn-3Ag-3Sb-xIn solder decreased, accompanied by less nucleation undercooling and an expanded melting range. The incorporation of In led to an enhancement in the yield and tensile strengths of the Sn-3Ag-3Sb-xIn solder alloys, but with a concomitant decrease in plasticity. In comparison to commercial Sn-3.0Ag-0.5Cu solder alloys, the yield strength and tensile strength of the Sn-3Ag-3Sb-3In alloy increased by 8.64 and 21.69 MPa, respectively, while the elongation decreased by 11.48%.
Originality/value
Sn-3Ag-3Sb-3In solder alloy was the most appropriate and expected comprehensive properties. The enhancements will provide substantial assistance and precise data references for the interconnection requirements in high-strength interconnection fields, such as automotive intelligent technology, 5G communication technology and high-performance computing.
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Jiacheng Zhou, Jinglin Shi, Lei Xu, Fuwen Zhang, Zhigang Wang, Qiang Hu and Huijun He
The reliability of solder joints is closely related to the growth of an intermetallic compound (IMC) layer between the lead-free solder and substrate interface. This paper aims to…
Abstract
Purpose
The reliability of solder joints is closely related to the growth of an intermetallic compound (IMC) layer between the lead-free solder and substrate interface. This paper aims to investigate the growth behavior of the interfacial IMC layer during isothermal aging at 125°C for Sn-3Ag-3Sb-xIn/Cu (x = 0, 1, 2, 3, 4, 5 Wt.%) solder joints with different In contents and commercial Sn-3Ag-0.5Cu/Cu solder joints.
Design/methodology/approach
In this paper, Sn-3Ag-3Sb-xIn/Cu (x = 0, 1, 2, 3, 4, 5 Wt.%) and commercial Sn-3Ag-0.5Cu/Cu solder were prepared for bonding Cu substrate. Then these samples were subjected to isothermal aging for 0, 2, 8, 14, 25 and 45 days. Scanning electron microscopy and transmission electron microscopy were used to analyze the soldering interface reaction and the difference in IMC growth behavior during the isothermal aging process.
Findings
When the concentration of In in the Sn-3Ag-3Sb-xIn/Cu solder joints exceeded 2 Wt.%, a substantial amount of InSb particles were produced. These particles acted as a diffusion barrier, impeding the growth of the IMC layer at the interface. The growth of the Cu3Sn layer during the aging process was strongly correlated with the presence of In. The growth rate of the Cu3Sn layer was significantly reduced when the In concentration exceeded 3 Wt.%.
Originality/value
The addition of In promotes the formation of InSb particles in Sn-3Ag-3Sb-xIn/Cu solder joints. These particles limit the growth of the total IMC layer, while a higher In content also slows the growth of the Cu3Sn layer. This study is significant for designing alloy compositions for new high-reliability solders.
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Jian‐Qiang Hu, Xin‐Lin Wang, Ge‐Lin Dai, Yi‐Wei Fei, Xian‐Yong Wei and Zhi‐Min Zong
Molybdenum dithiocarbamate (MoDDC) has good antiwear and friction‐reducing properties in lubricants, and can be protected against thermo‐oxidative degradation. However…
Abstract
Purpose
Molybdenum dithiocarbamate (MoDDC) has good antiwear and friction‐reducing properties in lubricants, and can be protected against thermo‐oxidative degradation. However, MoDDC‐containing lubricants may lose their ability to reduce friction over time, which may result from its concentration in oils below a critical concentration owing to oxidative degradation of MoDDC. Thus, in order to enhance the durability of the low friction performance of MoDDC, the paper aims to investigate good synergistic antioxidants with MoDDC.
Design/methodology/approach
The antioxidation properties of molybdenum dialkyldithiocarbamate (M 807) – and p,p‐dioctyldiphenylalmine (V 81) – or mixed octylated and butylated diphenylalmines (V 961)‐containing poly‐α‐olefin (PAO)‐derived lubricants were evaluated by differential scanning calorimetry (DSC) and modified penn state micro‐oxidation test (PMOT). DSC test measures incipient oxidation temperature (OT) and oxidation induction time (IT) of the lubricant at high temperatures and the oxidation stability of oil weight loss is measured by PMOT. Moreover, the oxidized samples were analyzed by Fourier transform infrared (FTIR) and electron spin resonance (ESR).
Findings
A DSC test shows that OT and IT of V 81‐ or V 961‐containing PAO were improved significantly by M 807 addition. A PMOT indicates that when combining with V 81 antioxidants, M 807 can also effectively reduce the increase in weight loss of PAO and deposits formed in oils. These results suggest that the M 807 shows a good antioxidative synergism with alkylated diphenylamine antioxidants. In addition, FTIR results from a PMOT confirm that the addition of M 807 can significantly enhance the oxidation IT of oils containing V 81 and inhibit formation of oxidation products including carbonyl bonds or hydroxyl group. ESR analysis from a PMOT indicates that M 807 may form stable radicals with arylamine by the coordination effect.
Originality/value
This paper provides simple and quick methods to evaluate synergistic antioxidation properties between different types of additives, and a mechanism of the inhibition involving a synergy was proposed. They can offer practical help in industrial applications and to an individual starting out on an academic career.
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Jian‐Qiang Hu, Xian‐Yong Wei and Zhi‐Min Zong
Pure 2,5‐dimercapto‐1,3,4‐thiadiazole (DMTD) disulfide dimer (DMS2) shows excellent four ball weld properties, however, the product is a solid material with relatively low initial…
Abstract
Purpose
Pure 2,5‐dimercapto‐1,3,4‐thiadiazole (DMTD) disulfide dimer (DMS2) shows excellent four ball weld properties, however, the product is a solid material with relatively low initial seizure load and exhibits certain corrosion, which accelerate oxidation of the lubricant by catalytic effect on metals. The author make efforts to resolve problems said by design a novel thiadiazole complex.
Design/methodology/approach
The complex of thiadiazole dimmer and polyglycol (DMS2‐GL) was synthesized as ashless grease additive. The antiwear and load carrying properties of the additive and their synergistic effects was evaluated by four ball tester in four types of lubricant grease. Moreover, corrosion inhibiting properties of compositions said was investigated by copper corrosion test.
Findings
The additive DMS2‐GL possessed good load carrying capacity, and exhibits good synergistic antiwear and load carrying prop with rust inhibitor. In addition, dates obtained from copper corrosion test show that it does not corrode copper but coats the metal with a film, and could improve the anticorrosion of corrosive additives molybdenum dialkyldithiophosphate (MoDDP) and molybdenum dibutyldithiocarbamate (MoDTC) by forming protective films on rubbing surface, which contribute to improving corrosion inhibiting property of greases. Finally, the tribo‐chemical mechanism was proposed that thiadiazole dimer and polyglycol could coordinate with each other by polydentate surface interaction, which means thiadiazole rings interact with the metal surface, polyglycol affords a bridging technology linked thiadiazole dimmers so as to lighten loads and strengthen forces between thiadiazole dimmer moleculars.
Originality/value
This paper provides a good ashless additive which has good antiwear, extreme pressure and corrosion inhibiting properties, and fulfils an identified resources need, which can offer practical help in industrial applications and to an individual starting out on an academic career.
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Cavitation erosion has always been a common technical problem in a hydraulic discharging structure. This paper aims to investigate the cavitation erosion behavior of hydraulic…
Abstract
Purpose
Cavitation erosion has always been a common technical problem in a hydraulic discharging structure. This paper aims to investigate the cavitation erosion behavior of hydraulic concrete under high-speed flow.
Design/methodology/approach
A high-speed and high-pressure venturi cavitation erosion generator was used to simulate the strong cavitation. The characteristics of hydrodynamic loads of cavitation bubble collapse zone, the failure characteristics and the erosion development process of concrete were investigated. The main influencing factors of cavitation erosion were discussed.
Findings
The collapse of the cavitation bubble group produced a high frequency, continuous and unsteady pulse load on the wall of concrete, which was more likely to cause fatigue failure of concrete materials. The cavitation action position and the main frequency of impact load were greatly affected by the downstream pressure. A power exponential relationship between cavitation load, cavitation erosion and flow speed was observed. With the increase of concrete strength, the degree of damage of cavitation erosion was approximately linearly reduced.
Originality/value
After cavitation erosion, a skeleton structure was formed by the accumulation of granular particles, and the relatively independent bulk structure of the surface differed from the flake structure formed after abrasion.
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– Reviews the latest management developments across the globe and pinpoints practical implications from cutting-edge research and case studies.
Abstract
Purpose
Reviews the latest management developments across the globe and pinpoints practical implications from cutting-edge research and case studies.
Design/methodology/approach
This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context.
Findings
Expansion into international markets has become one of the main growth strategies for many organizations. The blueprint is straightforward enough. Identify untapped potential and exploit the opportunities provided. Build a strong market position and reap lucrative rewards. If only it was that simple. Entering any new territory in the home nation is invariably demanding enough. Factor in the additional challenges inherent in any oversea venture and the difficulty soars to even greater heights. In any market, companies are subject to both technical and institutional demands which increase the complexity of decisions firms have to make. Pressures differ in each environment, so reacting in an appropriate manner is a must. Negotiating these demands effectively can go a considerable way in determining whether organizations ultimately succeed or fail.
Practical implications
Provides strategic insights and practical thinking that have influenced some of the world's leading organizations.
Originality/value
The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to digest format.
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Zhi‐Qiang Lian, Yuan‐Xian Gu and Hong‐Wu Zhang
Based on the unilateral CT images of a patient in stage III for osteonecrosis of the femoral head, three subject‐specific three‐dimensional finite element models of proximal femur…
Abstract
Based on the unilateral CT images of a patient in stage III for osteonecrosis of the femoral head, three subject‐specific three‐dimensional finite element models of proximal femur are developed by reverse engineering method, including normal model, necrosis model and prothetic model. Based on the same CT set, the material properties are assigned to each finite element model. Then, by finite element analysis, the process of bone grafting for osteonecrosis of the femoral head is simulated. The results indicate that when the necrosis parts of femoral head are removed, the stresses and displacements of proximal femur increase correspondingly, but after the surgery of bone grafting, the stresses and displacements of proximal femur efficiently decrease and become more close to the normal state. The results are useful for a better understanding of the procedure of the bone grafting surgery.
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Shailendra Singh, Mahesh Sarva and Nitin Gupta
The purpose of this paper is to systematically analyze the literature around regulatory compliance and market manipulation in capital markets through the use of bibliometrics and…
Abstract
Purpose
The purpose of this paper is to systematically analyze the literature around regulatory compliance and market manipulation in capital markets through the use of bibliometrics and propose future research directions. Under the domain of capital markets, this theme is a niche area of research where greater academic investigations are required. Most of the research is fragmented and limited to a few conventional aspects only. To address this gap, this study engages in a large-scale systematic literature review approach to collect and analyze the research corpus in the post-2000 era.
Design/methodology/approach
The big data corpus comprising research articles has been extracted from the scientific Scopus database and analyzed using the VoSviewer application. The literature around the subject has been presented using bibliometrics to give useful insights on the most popular research work and articles, top contributing journals, authors, institutions and countries leading to identification of gaps and potential research areas.
Findings
Based on the review, this study concludes that, even in an era of global market integration and disruptive technological advancements, many important aspects of this subject remain significantly underexplored. Over the past two decades, research has lagged behind the evolution of capital market crime and market regulations. Finally, based on the findings, the study suggests important future research directions as well as a few research questions. This includes market manipulation, market regulations and new-age technologies, all of which could be very useful to researchers in this field and generate key inputs for stock market regulators.
Research limitations/implications
The limitation of this research is that it is based on Scopus database so the possibility of omission of some literature cannot be completely ruled out. More advanced machine learning techniques could be applied to decode the finer aspects of the studies undertaken so far.
Practical implications
Increased integration among global markets, fast-paced technological disruptions and complexity of financial crimes in stock markets have put immense pressure on market regulators. As economies and equity markets evolve, good research investigations can aid in a better understanding of market manipulation and regulatory compliance. The proposed research directions will be very useful to researchers in this field as well as generate key inputs for stock market regulators to deal with market misbehavior.
Originality/value
This study has adopted a period-wise broad-based scientific approach to identify some of the most pertinent gaps in the subject and has proposed practical areas of study to strengthen the literature in the said field.
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Hong Hu, Qiang Wang and Jixiang Chen
Why do some small and medium-sized enterprises (SMEs) explore more while others exploit further? What are the driving forces of their exploratory and exploitative innovation…
Abstract
Purpose
Why do some small and medium-sized enterprises (SMEs) explore more while others exploit further? What are the driving forces of their exploratory and exploitative innovation? These are intriguing questions worthy of in-depth research. The purpose of this paper is to crack these problems from both objective (i.e. organizational slack) and subjective (i.e. market orientation) perspectives. Specifically, the paper examines the effects of unabsorbed and absorbed slack on exploratory and exploitative innovation and the mediating roles played by proactive and responsive market orientation.
Design/methodology/approach
The authors collected data from 214 SMEs in several industries of China. These businesses were located in the city of Shanghai and the provinces of Jiangsu and Zhejiang in the southeastern part of China. The survey method was used to test the hypotheses.
Findings
Results reveal that unabsorbed and absorbed slack could affect exploratory and exploitative innovation. Proactive and responsive market orientation are related to unabsorbed and absorbed slack, exploratory and exploitative innovation, and they play the roles of mediators in two sets of the relationships.
Research limitations/implications
This research presents several profound insights for venture capitalists regarding to making investment decisions and for the entrepreneurs of SMEs in terms of how much resource slack they should gain and retain to reach intended level of exploratory and exploitative innovation. Some of the limitations of this study relate to the single respondent in each firm, lack of examination on relevant contextual factors and potential moderators.
Originality/value
This study addresses the gaps in the literature by exploring the mechanisms underlying the effects of different kinds of organizational slack on the two elements of ambidextrous innovation in non-large-scale businesses in a non-Western cultural setting.
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