Phase transitions and electrical properties of (Na0.5K0.5)NbO3-Bi(Sc0.5Fe0.5)O3 lead-free piezoelectric ceramics

Hongfu Wang,Ailing Ding 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.1

Lead-free ceramics (1-x)(Na0.5K0.5)NbO3-xBi(Sc0.5Fe0.5)O3 (KNN-BSF, x = 0−0.08) were synthesized by conventional solid-state sintering. A morphotropic phase boundary (MPB) is formed in the ceramics near x = 0.01−0.02 at room temperature by Xray analysis. Dielectric temperature spectra indicate the existence of two dielectric anomalous peaks, which correspond to orthorhombic-tetragonal (TOT) and tetragonal-cubic (TC) transitions. The ceramic with x = 0.0125 near the MPB exhibits the following optimal electrical properties: Pr = 33.9 μC/cm2, Ec = 18.1 kV/cm, d33 = 255 pC/N, kp = 0.44, and Tc = 372 oC.

Exploring the Experiences of Chinese Wushu Majors in Their Career Transition to Korean TAEKWONDO Leaders

Hongfu Tang,Jaebum Lee,Sile Wang J-INSTITUTE 2021 International Journal of Martial Arts Vol.6 No.2

Purpose: The purpose of this study was to apply a phenomenological approach, a qualitative research method, to explore the common experiences of Wushu majors in China in the process of giving up their move-ments and transitioning to Korean Taekwondo leaders. Method: For the selection of participants in the study, 6 participants aged 27 to 30 years old with experience in Wushu with more than 10 years of experience in competition as a student athlete were selected as a purpos-ive sampling method among nonprobability sampling. In the analysis process, through the analysis framework of Giorgi s 4th stage the analysis process is conducted to identify text content from a holistic perspective, seg-mentation of semantic units, transformation into academic language, and integrating the converted semantic units into a structure. Results: The results of the study were divided into situational structured statements and general structured statements, and in the situational structured statement, 5 elements, 16 sub-elements, and a total of 54 seman-tic units were found. According to the data analysis, five major components were found in the meaning of a Chinese Wushu major s career transition to a Korean Taekwondo leader: a hardened Wushu education sys-tem , a lack of Wushu operation management system , choice of Taekwondo as a popular job , and regret and desire of giving up on Wushu . Conclusion: This study suggest in concrete and vivid language why Wushu majors, who represent Chinese culture and are loved by Chinese people, switch to Taekwondo leaders. It was possible to examine the reasons why Wushu majors drop out, and through this, it was possible to discover the intrinsic and external problems perceived by Wushu majors. In addition, it is said that the research is meaningful in that it has suggested pro-posal for the sustainable development of Wushu majors through the research results.

The Effect of Emulsifying Capacity of ASP Flooding on Oil Displacement Efficiency for Jing-11 Fault Block Reservoir in Huabei Oil Field

Xuwei He,Hongfu Fan,Fei Ni,Haihui Chen,Zhongwei Wu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.1

Although started late, the development of ASP flooding technology in China was rapid. With the spread of the field test of ASP flooding, the effect of the emulsifying property of the composite system during the process of seepage on the oil displacement efficiency has gradually become the problem that people are concerning. In this paper, taking Jing-11 fault block reservoir in Huabei Oil Field as the research object, the influence rule of alkali, surfactant and polymer on the stability of the crude oil emulsion was inspected through indoor experiment. Besides, on the basis of the controlling variables method and under the circumstance of other conditions remains unchanged, the simulated displacement experiment was conducted using the physical model for ASP system of emulsion type and non-emulsion type surfactant respectively. It is proved that the emulsifying capacity of ASP flooding has significant effect on improving the oil displacement efficiency.

Effects of feeding corn naturally contaminated with aflatoxin on growth performance, apparent ileal digestibility, serum hormones levels and gene expression of Na+, K+-ATPase in ducklings

Farzana Abbasi,Jingbo Liu,Hongfu Zhang,Xiaoyun Shen,Xuegang Luo 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.1

Objective: A 14-d trial was conducted to determine the effects of feeding corn naturally contaminated with aflatoxin B1 (AFB1) on growth performance, apparent ileal digestibility, serum hormones levels and gene expression of Na+, K+-ATPase in ducklings. Methods: A total of 704 ducklings were blocked on the basis of sex and body weight (BW), and then allocated randomly to one of the following two treatments: i) CON, basal diet and ii) AFB1, diets with 100% of normal corn replaced with AFB1 contaminated corn. There were 22 pens per treatment and 16 birds per pen. The concentration of AFB1 was 195.4 and 124.35 μg/kg in the contaminated corn and AFB1 diet, respectively. Results: The AFB1 decreased average daily gain, average daily feed intake, d 7 BW, final BW in the whole trial, and feed conversion ratio (FCR) during d 8 to 14 and d 1 to 14 by 10% to 47% (p<0.05), while FCR during d 1 to 7 was increased (p<0.05). AFB1 did not affect mortality to 7 d of age, and then increased to 5.8% from 8 to 14 d of age (p<0.01). Apparent ileal gross energy digestibility was reduced by AFB1, whereas apparent ileal digestibility of dry matter, nitrogen, and amino acid was improved (p<0.01). Feeding AFB1 diets increased serum concentration of leptin and insulin-like growth factors-1 (IGF-1) (p<0.05), but had no effect on neuropeptide Y, ghrelin, cholecystokinin-8 or insulin (p>0.05). Dietary treatments did not influence relative expression of jejunal Na+, K+-ATPase gene (p>0.05). Conclusion: Taken together, feeding corn naturally contaminated with AFB1 reduced growth performance, improved apparent ileal digestibility, and affected serum leptin and IGF-1 in ducklings from d 1 to 14.

Effects of vortex generators on the wind load of a flat roof: A computational study

Yagebai Zhao,Xiaolong Deng,Hongfu Zhang,Dabo Xin,Zhiwen Liu 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.1

Vortex generators are commonly used in mechanical engineering and the aerospace industry to suppress flow separation owing to their advantages of simple structure, economic viability, and high level of efficiency. Owing to the flow separation of the incoming wind on the leading edge, a suction area is formed on the roof surface, which results in a lifting effect on the roof. In this research, vortex generators were installed on the windward surface of a flat roof and used to disturb to roof flow field and reduced suction based on flow control theory. Computational fluid dynamics (CFD) simulations were performed in this study to investigate the effects of vortex generators on reduce suction. It was determined that when the vortex generator was installed on the top of the roof on the windward surface, it had a significant control effect on reduce suction on the roof leading edge. In addition, the influence of parameters such as size, placement interval, and placement position of the vortex generator on the control effect of the roof’s suction is also discussed.

Investigation of Grinding Characteristic using Nanofluid Minimum Quantity Lubrication

Cong Mao,Xiaojun Tang,Hongfu Zou,Xiangming Huang,Zhixiong Zhou 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Conventional grinding fluid is widely used in grinding process, which results in high consumption and impacting the environment. The promising alternative to conventional dry and fluid coolant application is minimum quantity lubrication (MQL). It is known that the cooling and lubrication performance of the grinding fluid is the key technical area for the success application of MQL grinding process. In this study, Water based Al2O3 nanofluid was applied to grinding process with MQL approach for its excellent convection heat transfer and thermal conductivity properties. The grinding characteristics of hardened AISI 52100 steel were investigated and compared with those of wet, dry and pure water MQL grinding. Experimental results show that water based Al2O3 nanofluid MQL grinding can significantly reduce the grinding temperature, decrease the grinding forces, improve the ground surface morphology and reduce the surface roughness in comparison to pure water MQL grinding. Furthermore, the cooling and lubricating mechanism for nanofluid MQL grinding was discussed in detail.

Preparation and characterization of phytosterol-loaded nanoparticles with sodium caseinate/dextran conjugates

Feifan Li,Xiaoli Wang,Hongfu Wang,Xiaohong Mei 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.4

Sodium caseinate (SC)/dextran conjugates wereprepared via Maillard reaction under controlled dry-heatingconditions. Moreover, the nanoparticles of phytosterols(PS) encapsulated by SC or SC/dextran were producedusing the emulsion evaporation method. The encapsulationefficiency (78.81 ± 5.22%) of PS in SC/dextran nanoparticleswas higher than that (73.5 ± 2.78%) in SCnanoparticles. Compared with the compact and densestructure of SC nanoparticles, SC/dextran nanoparticlesexisted as relatively loose aggregates. The result of differentialscanning calorimetry demonstrated that theencapsulation of PS greatly decreased its crystallinity. Thereleased rates of PS from SC and SC/dextran nanoparticlesunder acidic gastric conditions were 8.59% and 4.73%,respectively. After 7 h of intestinal digestion, the releasedrate (52.19%) of PS from SC/dextran nanoparticles wassignificantly higher than that from SC (32.67%) nanoparticles. Therefore, SC/dextran conjugates prepared by theMaillard reaction are more suitable to be used as wallmaterial for the nano-encapsulation of PS.

A Slope One and Clustering based Collaborative Filtering Algorithm

An Gong,Yun Gao,Zhen Gao,Wenjuan Gong,Huayu Li,Hongfu Gao 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.4