Experimental Determination of Interfacial Energies for Solid Sn in Equilibrium with Sn-Mg-Zn Liquid

Yemliha Altıntas,Esra Öztürk,Sezen Aksöz,Kâzım Keşlioğlu,Necmettin Maraşlı 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.2

The equilibrated grain boundary groove shapes of solid Sn in equilibrium with Sn-Mg-Zn liquid were observedfrom a quenched sample by using a radial heat flow apparatus. The Gibbs-Thomson coefficient, solid-liquidinterfacial energy and grain boundary energy of solid Sn were determined from the observed grain boundarygroove shapes. The thermal conductivity of the eutectic solid phase for Sn-8.12 at% Mg-4.97 at% Zn alloy and thethermal conductivity ratio of the liquid phase to the solid phase for Sn-8.12 at% Mg-4.97 at% Zn alloy at eutectictemperature were also measured with a radial heat flow apparatus and a Bridgman-type growth apparatus,respectively. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy of solidSn in equilibrium with Sn-Mg-Zn liquid were determined to be (8.3 ± 0.6)×10-8 Km, (118.5 ± 14.2)×10-3 Jm-2and (225.1 ± 29.3)×10-3 J m-2 respectively from observed grain boundary groove shapes. A comparison ofpresent results for solid Sn in the Sn-8.12 at% Mg-4.97 at% Zn alloy with the results obtained in previous worksfor similar solid Sn in equilibrium with different binary or ternary liquid was made.

Variations of microhardness with solidification parameters and electrical resistivity with temperature for Al–Cu–Ag eutectic alloy

U. Böyük,N. Maraşlı,E. Çadırlı,H. Kaya,K. Keşlioğlu 한국물리학회 2012 Current Applied Physics Vol.12 No.1

AleCueAg eutectic alloy was directionally solidified upwards with different growth rates (1.83e 498.25 mm/s) at a constant temperature gradient (8.79 K/mm) and with different temperature gradients (3.99e8.79 K/mm) at a constant growth rate (8.30 mm/s) by using a Bridgman type directional solidification apparatus. The dependence of microhardness (HV) on the growth rate (V), temperature gradient (G) and microstructure parameter (l) were found to be HV ¼ k1 V0.10, HV ¼ k2 G0.13 and HV ¼ k3 l 0.22, respectively. The electrical resistivity of the AleCueAg eutectic cast alloy increases linearly with the temperature in the range of 300e780 K. The enthalpy of fusion and specific heat change during melting for same alloy were also determined to be 223.8 J/g, and 0.433 J/g K, respectively by a differential scanning calorimeter from heating curve during the transformation from eutectic solid to eutectic liquid.

An Evaluation of the Coupling Coordination Degree of the Yangtze River Delta Port Cluster Based on Coupling Theory

Lu Ke,오용식(Yong-Sik Oh) 한국항해항만학회 2024 한국항해항만학회지 Vol.48 No.2

To quantitatively assess the correlation between subsystems within a port cluster and the overall coordinated development of the port group, the current paper evaluates the coordinated development of port clusters. First, we construct an evaluation index system for the coupling and coordination of port clusters. Next, we introduce the contribution index of port subsystems, coupling degree, and coupling coordination degree functions to formulate a coupling coordination evaluation model for the port cluster. Finally, we use the Yangtze River Delta port cluster as a case study for validation, specifically using empirical data from 2012 to 2021. The findings reveal distinct phased characteristics in the coupling and coordination of port clusters in the Yangtze River Delta, marked by a notable transition from “maladjustment” to “coordination.” Further, sustained high coupling values over a decade indicate a significant level of competition and cooperation among ports within the Yangtze River Delta port cluster. Over time, this competitive and collaborative dynamic has progressively evolved toward a more positive and structured direction. Lastly, it is expected that the evaluation model proposed in this paper can be extrapolated to other port clusters to gauge the extent of coordinated development, thereby facilitating horizontal comparisons and vertical analyses.

Fatigue evaluation and CFRP strengthening of diaphragm cutouts in orthotropic steel decks

Lu Ke,Chuanxi Li,Jun He,Yongjun Lu,Yang Jiao,Yongming Liu 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.4

The cracking at the transverse diaphragm cutout is one of the most severe fatigue failures threatening orthotropic steel decks (OSDs), whose mechanisms and crack treatment techniques have not been fully studied. In this paper, full-scale experiments were first performed to investigate the fatigue performance of polished cutouts involving the effect of an artificial geometrical defect. Following this, comparative experimental testing for defective cutouts strengthened with carbon fiber-reinforced polymer (CFRP) was carried out. Numerical finite element analysis was also performed to verify and explain the experimental observations. Results show that the combinative effect of the wheel load and thermal residual stress constitutes the external driving force for the fatigue cracking of the cutout. Initial geometrical defects are confirmed as a critical factor affecting the fatigue cracking. The principal stress 6 mm away from the free edge of the cutout can be adopted as the nominal stress of the cutout during fatigue evaluation, and the fatigue resistance of polished cutouts is higher than Grade A in AASHTO specification. The bonded CFRP system is highly effective in extending the fatigue life of the defective cutouts. The present study provides some new insights into the fatigue evaluation and repair of OSDs.

Capacity Evaluation Model of Enterprise Technological Innovation Complex System and Its Application

Ke-Bin Lu,Jun-Jie Huang,Qiang Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.4

Under the background of complex system of enterprise innovation, based on the self-organization theory and collaborative theory, it is thought that the enterprise technology innovation system belongs to the grey system, for this reason, build the grey relational analysis model of the enterprise technology innovation system capability evaluation, and use weight coefficient method to optimize. Finally, use the optimization model to evaluate the technological innovative ability of seven enterprises; the results show that the built enterprise technology innovation system ability evaluation model is effective, and it can offer the innovation ability value of different enterprises accurately, providing the useful decision-making reference for the enterprise technology innovation system and the optimization of technological innovation cooperative system.

Pathogenesis Division of Black Rot Bacteria of Chinese Cabbage in Shaanxi Central Productive Area

Lu-gang Zhang,Yan Lu,Mai-xia Hui,Ming-ke Zhang 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

Study on Data Privacy Monitoring of Cloud Computing and Access Control Strategy

Ke Lu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.7

Bibliometric analysis of researches on traditional Chinese medicine for coronavirus disease 2019 (COVID-19)

Ke-Lu Yang,Xin-Yao Jin,Ya Gao,Jin Xie,Ming Liu,Junhua Zhang,Jin-Hui Tian 한국한의학연구원 2020 Integrative Medicine Research Vol.9 No.3

Background: The coronavirus disease 2019 (COVID-19) has caused a worldwide pandemic, and traditional Chinese medicine (TCM) has played an important role in response. We aimed to analyze the published literature on TCM for COVID-19, and provide reference for later research. Methods: This study searched the CBM, CNKI, PubMed, and EMBASE from its establishment to March 11, 2020. VOSviewer 1.6.11 and gCLUTO 2.0 software were used to visually analyze the included studies. Results: A total of 309 studies were included, including 61 journals, 1441 authors, 277 institutions, and 27 provinces. Research collaborations among regions were among those close in geographical distance. The collaborations of institutions and authors were more likely to be restricted to the same region. Among the authors with frequency greater than two (65 authors), only 19 authors had connection with others. More than 70% (358/491) of keywords were only presented once, and 20 keywords were shown more than 10 times. Five research topics were identified: Data mining method based analysis on the medication law of Chinese medicine in prevention and management of COVID-19; exploration of active compounds of Chinese medicine for COVID-19 treatment based on network pharmacology and molecular docking; expert consensus and interpretation of COVID-19 treatment; research on the etiology and pathogenesis of COVID-19; and clinical research of TCM for COVID-19 treatment. Conclusion: The research hotspots were scattered, and the collaboration between authors and institutions needed to be further strengthened. To improve the quality and efficiency of research output, the integration of scientific research and resources, as well as scientific collaboration are needed.

Network Scheduling Model of Cloud Computing based on Particle Swarm Optimization Algorithm

Ke Lu,Junxia Meng 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.4

The paper proposed a network scheduling in cloud computing based on intelligence Particle Swarm Optimization algorithm aimed at the disadvantages of cloud computing network scheduling. Firstly, on the basis of cloud model, used intelligence Particle Swarm Optimization algorithm with strong ability of global searching to find the better solution of cloud computing network scheduling then turned the better solution into the initial pheromone of improved Particle Swarm Optimization algorithm, and found out the cloud computing network scheduling and the algorithm’s global optimal solution through improved Particle Swarm Optimization information communications and feedbacks. Finally, made comparison test of the three benchmark function on the basis of MATLAB, the results showed, compared with traditional intelligence Particle Swarm Optimization algorithms, the improved algorithm can preferably allocate the resources in cloud computing model, the effect of prediction model time is more close to actual time, can efficiently limit the possibility of falling into local convergence, the optimal solution’s time of objective function value is shorten which meet the user’s needs more.

The Relationship between Ports and City Growth: The Case of Ningbo

Lu Ke,오용식 한국무역연구원 2023 무역연구 Vol.19 No.1

Purpose – The purpose of this paper is to explore the relationship between port and city growth with the help of the port impact curve and relative concentration index (RCI). This is done from the two aspects of (1) clarifying the characteristics of the interaction between Ningbo port and city, and (2) clarifying the phased development of the relationship between Ningbo port and city. Design/Methodology/Approach – Based on the method of the port impact curve and RCI, we conduct a case study of Ningbo, a port-city in Southeast China, and we also make a meaningful comparison between Ningbo and other famous port cities in China. Findings – This paper finds that Ningbo port and city have been in a relatively loose relationship from 2010 to 2021. Over these 12 years, the relationship between Ningbo port and city has shown signs of changing from the stage of agglomeration and diffusion effect to the stage of urban self-growth effect. Also, we find that, compared with other port cities, the positive correlation between Ningbo port cargo throughput and urban economy development is relatively weak. However, Ningbo’s export-oriented economic characteristics form a certain boost for the development of port container throughput. Research Implications – In the management of this paper, this study revealed the flexibility and complexity of the port-city relationship, suggesting that the stage characteristics of the port-city relationship should be combined on the road of the sustainable development of ports and cities, which will also provide reference for follow-up research.