Behavior and Mechanism of Void Welding Under Thermal Mechanical Coupling

Fei Chen,Xitao Wang,Huiqin Chen,Shue Dang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Shrinkage cavity, microporosity, blowhole and the likes are the typical void defects in ingot. Only through reasonable hightemperature deformation and heat preservation process can the void defects be closed and welded to ensure the high qualityof forgings. However, there are few researches on the welding behavior of voids, and the understanding of the void weldingmechanism is still insufficient. In order to further study the welding behavior of void and explore the welding mechanism,the welding process of void and microstructure evolution around void under thermal mechanical coupling were studied byphysical simulation. The results show that heating temperature, holding time, plastic deformation play an important role invoid welding. The void welding degree increases with the increase of heating temperature, holding time and plastic deformation. Besides, there are three main welding mechanisms for void defects, including the volume of microvoids decreasesdue to vacancy diffusion, the void welding mechanism caused by the austenite-ferrite transformation at lower temperaturesand the void welding mechanism caused by recrystallization and grain growth of austenite grains at higher temperatures.

Interview with Professor Fei-Ling Wang, author of The China Order: Centralia, World Empire, and the Nature of Chinese Power (2017)

Jaewoo Choo(토론자),Fei-Ling Wang(토론자) 동북아역사재단 2017 Journal of Northeast Asian History Vol.14 No.2

A small hairpin RNA targeting myeloid cell leukemia-1 enhances apoptosis in host macrophages infected with Mycobacterium tuberculosis

Fei-yu Wang,Yu-qing Zhang,Xin-min Wang,Chan Wang,Xiao-fang Wang,Jiang-dong Wu,Fang Wu,Wan-jiang Zhang,Le Zhang 한국미생물학회 2016 The journal of microbiology Vol.54 No.4

Myeloid cell leukemia-1 (Mcl-1) plays an important role in various cell survival pathways. Some studies indicated that the expression of Mcl-1 was upregulated in host cells during infection with the virulent Mycobacterium tuberculosis strain, H37Rv. The present study was designed to investigate the effect of inhibiting Mcl-1 expression both in vivo and in vitro on apoptosis of host macrophages infected with M. tuberculosis using a small hairpin (sh)RNA. Mcl-1 expression was detected by the real time-polymerase chain reaction, western blotting, and immunohistochemistry. Flow cytometry and transmission electron microscopy were used to measure host macrophage apoptosis. We found elevated Mcl-1 levels in host macrophages infected with M. tuberculosis H37Rv. The expression of Mcl-1 was downregulated efficiently in H37Rv-infected host macrophages using shRNA. Knockdown of Mcl-1 enhanced the extent of apoptosis in H37Rv-infected host macrophages significantly. The increased apoptosis correlated with a decrease in M. tuberculosis colony forming units recovered from H37Rv-infected cells that were treated with Mcl-1-shRNA. Reducing Mcl-1 accumulation by shRNA also reduced accumulation of the anti-apoptotic gene, Bcl-2, and increased expression of the pro-apoptotic gene, Bax, in H37Rv-infected host macrophages. Our results showed that specific knockdown of Mcl-1 expression increased apoptosis of host macrophages significantly and decreased the intracellular survival of a virulent strain of M. tuberculosis. These data indicate that interference with Mcl-1 expression may provide a new avenue for tuberculosis therapy.

Genome-Wide Association Analysis to Search for New Loci Associated with Lifelong Premature Ejaculation Risk in Chinese Male Han Population

Wang Fei,Luo Defan,Chen Jianxiang,Pan Cuiqing,Wang Zhongyao,Fu Housheng,Xu Jianbing,Yang Meng,Mo Shaowei,Zhuang Liying,Ye Liefu,Wang Weifu 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.2

Purpose: Genetic factors play an indispensable role in the pathogenesis of lifelong premature ejaculation (LPE). The suscep-tibility genes/SNPs that have been discovered are very limited and can only explain part of the genetic effects of LPE. There-fore, discovering more genetic polymorphisms associated with the occurrence and development of LPE will help reveal the pathogenesis of LPE. Materials Materials and and Methods:Methods: We conducted a genome-wide association study of LPE in 486 Chinese male Han people (cases and controls). We used Gene Titan multi-channel instrument and Axiom Analysis Suite 6.0 software for genotyping. Imputation was performed by IMPUTE2 software and the 1000 Genomes Project (Phase3) was used as reference for haplotype. Finally, logistic regression analysis was performed on all loci that passed the quality control. The odds ratio and 95% confidence in-terval were calculated to determine the association between each SNPs and Chinese male Han population LPE risk. Results:Results: The results showed that a total of 33 genetic variants in 13 genes (LACTBL1 , SSBP3 , ACOT11 , LINC02486 , TMEM154, LINC01098, NONE, HCG27, HLA-C, TNFSF8, TNC, FAM53B, SULF2) have a suggestively significant genome-wide association with LPE risk (p<5×10-6). Conclusions:Conclusions: This study is the first to conduct a GWAS on LPE in Chinese male Han population 33 genetic polymorphisms have a suggestive genome-wide association with LPE risk. This study have provided data supplement for the genetic loci of LPE risk, and laid a scientific foundation for the pathogenesis and the targeted therapy of LPE.

Colossal permittivity in (Li + Nb) co-doped Fe2O3 ceramics

Fei Y.M.,Wang Q.Q.,Sun J.,Wang S.T.,Li T.Y.,Wang J.,Wang C.C. 한국물리학회 2020 Current Applied Physics Vol.20 No.7

(Li + Nb) co-doped (Li + Nb)xFe2-xO3 (with x = 0.0005, 0.005, 0.05, and 0.1) ceramics were prepared by solgel method. Their structural, dielectric, humidity, and magnetic properties were investigated. Colossal permittivity (~104) was approached or achieved in all doped samples even with a very small doping level of x = 0.0005. The colossal permittivity behavior is composed of two dielectric relaxations with the low-temperature one being a polaron relaxation due to electrons hopping between Fe3+ and Fe4+ ions and the hightemperature one being a Maxwell-Wagner relaxation caused by humidity-sensing properties.

Numerical Simulation of Semi-blunt Puncture Behaviors of Woven Fabrics Based on the Finite Element Method

Fei-Fei Wang,Yan-Li Ma,Lan Xu,Ping Wang,Yan Zhang 한국섬유공학회 2018 Fibers and polymers Vol.19 No.11

This paper focuses on the semi-blunt puncture behavior of woven fabrics via finite element analysis (FEA) approaches. In these finite element (FE) models, main structure parameters, such as weave structure, warp density as well as friction coefficient, are systematically considered and calculated via FEA. These microstructure geometrical models are builtup with full consideration of interaction between warp and weft yarns. The theoretical results show that plain woven fabric has better puncture resistance compared with 2/1 twill and 5-harness satin fabrics. With the increase of warp density and friction coefficient, the puncture property of woven fabric will be dramatically improved. Finally, an energy consumption method is adopted to analyze the puncture damage process of woven fabric. The simulation results will benefit for the optimum design of woven fabric with excellent puncture performance.

Preparation and Properties of WS₂/Co<SUB>9</SUB>S<SUB>8</SUB> Core-shell Nanocrystals@Hollow-porous Carbon Fiber (HCF) for Water Electrolysis

Fei-fei Wang,Ping Wang,Ick Soo Kim 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

Developing highly-efficiency, cost-effective, high-throughput and durable bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is of paramount important for water electrolysis. Herein, we report an economical method for the synthesis of WS₂, Co9S8 and WS₂/Co9S8 nanocrystals with different diamension, structure and morphology grown on hollowporous carbon fiber (HCF) via calcination and S vapor inducing reaction treatment as bifunctional catalysts for water electrolysis. Then, the effects of structure and morphology on the water electrolysis of WS₂ and (or) Co9S8@hollow-porous carbon fiber (HCF) were investigated. The catalyst W₁Co₁S@HCF with W/Co molar ratio of 1:1 presented excellent HER activity for 228 ± 8.38 mV overpotential at a current density of 10 mA/cm² with the Tafel slope of 111 mV/dec. More importantly, the W1Co1S@HCF had superior stability in acidic electrolyte solution. The catalyst W₁Co₃S@HCF with W/Co molar ratio of 1:3 gained excellent OER activity for 437 ± 19.47 mV overpotential at a current density of 10 mA/cm² with the Tafel slope of 99 mV/dec. The excellent electrocatalytic actives can be attributed to the synergetic effects of appropriate molar ratio WS₂/Co9S8 core-shell and hollow-porous structure in addition to providing more potential implantation sites.

Controlling Ejection State of a Pneumatic Micro-droplet Generator Through Machine Vision Methods

Fei Wang,Yiwei Wang,Weijie Bao,Hui Zhang,Jiangeng Li,Zhihai Wang 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.4

Pneumatic micro-droplet ejection is a printing technique that has potential applications in many fi elds, especially in thefi eld of bio-printing. The ejection is via a solenoid valve being briefl y turned on, so that high pressure gas enters the liquidreservoir, forming a gas pressure pulse, forcing the liquid out through a tiny nozzle to form a micro-droplet. For bio-printingapplications, the bio-inks are typically non-standard. The diffi culties are not only that the initial working parameters arediffi cult to set, but also the working conditions change over time in many cases. In order to maintain a stable single-dropejection state, a machine vision based ejection monitoring was designed to obtain the number, positions and sizes of thedroplets for each ejection, and a feedback control is realized by adjusting the “ON” time of the solenoid valve or the gaspressure at the front end of the solenoid valve.

중소수출기업의 무형자산이 수출성과에 미치는 영향에 관한 연구

왕비비(Fei-Fei Wang),김영일(Young-il Kim),권영철(Yung-Chul Kwon) 한국무역학회 2012 貿易學會誌 Vol.37 No.5

‘이따금’ 관련 유의어의 통시적 고찰

왕비비(Fei-Fei Wang) 한국중원언어학회 2016 언어학연구 Vol.0 No.40

In Korean, the directions of research on synonyms can be roughly classified into three categories: general, synchronic, and diachronic. Compared to the others, the diachronic research has drawn relatively inconsiderable attention because it usually requires a huge mass of historical data. With this background, this study was intended to explore the changing patterns of time adverb synonyms related to ‘ittakeum’ from a diachronic point of view. There are many synonyms related to ‘ittakeum’ from middle to modern Korean, such as ‘istakam,’ ‘meurimeuriye,’ ‘teoteoreo,’ ‘oangoangae,’ ‘yusiye,’ ‘siro,’ ‘siye,’ ‘sisiro,’ ‘sisiye,’ ‘ttaettaero,’ and ‘kankan.’ They were divided into two groups: Sino- and Native Korean. In each group, the form and meaning of every individual synonym which underwent some changes were analyzed by a diachronic approach. The result of diachronic changes in a synonymic rivalry is that some synonyms became extinct according to a comprehensive review of the literature. In the course of alteration, are involved some factors: ‘syllable numbers,’ ‘form stability,’ and ‘meaning load.’