Influence of Microstructure and Mechanical Properties on Formability in High Strain Rate Rolled AZ31 Magnesium Alloy Sheets

Fubao Liu,Xiao Liu,Biwu Zhu,Hui Yang,Gang Xiao,Mingyue Hu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

High strain-rate rolling (≥ 10 s−1) has been successfully employed to produce AZ31 magnesium alloy sheets to a high reductionof 82% with a fine grain structure in a single pass. The rolled sheets inevitably undertake various forming processessuch as press and deep forming in the fabrication stage. To investigate the formability, the Erichsen tests were carried out onhigh strain rate rolled AZ31 magnesium alloy sheets at room temperature. The relationship among mechanical properties,microstructure and formability were investigated. The crack behavior during Erichsen tests was also studied. It was foundthat the formability was related to the lowest in-plane tensile strengthen and dislocation density of initial microstructure. The competitive relationship between micro-crack and twinning/shear bands would also influence the formability of highstrain rate rolled magnesium alloy sheets. Deformed shear band with substaintial twins prohibits the crack extension andenhances strengthen of materials in front of crack tip.

"五四"何以失精神

劉慧軍 한국중국문화학회 2000 中國學論叢 Vol.9 No.-

5·4운동은 중국 역사상 위대한 사상변혁운동이다. 5·4운동이 제창한 "立人"사상은 당시뿐만 아니라 현재에 있어서도 중국문화의 발전과 변화에 중요한 의의를 지니고 있다. 그러나 여러 가지 원인 때문에 5·4정신은 잊혀졌다. 본고는 정치와 문화적 측면에서 5·4정신이 잊혀지게 된 원인을 검토한 바, 다음 3가지가 주된 원인으로 작용하였다고 분석하였다. 첫째, 중국전통문화의 뿌리가 확고하여 민주사상이 단시간 내에 확립될 수 없었다. 둘째, 정치의 막강한 흡인력이 신문화운동 발전에 영향을 미쳐 지식인이 문화적 사고를 포기하여, 중국의 사상계몽이 시작되자마자 중단되었다. 셋째, 5·4운동 후 권력자의 남용이 5·4정신을 잊혀지게 하는 중요한 원인이 되었다.

Design of 3-electrode system for <i>in situ</i> monitoring direct methanol fuel cells during long-time running test at high temperature

Liu, Guicheng,Li, Xinyang,Wang, Hui,Liu, Xiuying,Chen, Ming,Woo, Jae Young,Kim, Ji Young,Wang, Xindong,Lee, Joong Kee Elsevier 2017 APPLIED ENERGY Vol.197 No.-

<P>To understand the effect mechanisms of long-time running and high operation temperature on performance of the direct methanol fuel cell (DMFC) more clearly and directly, in this paper, a new design of 3-electrode system with a solution-type salt bridge has been developed to distinguish the integral polarization into anodic and cathodic polarizations at various temperatures and explore the attenuation mechanism by in situ monitoring the potential of anode during long-time running process at 80 degrees C, for the first time. The results indicate that the optimized 3-electrode system consists of a standard calomel electrode (SCE) and a solution-type salt bridge placed in the anode hole filled by 0.5 mol L-1 H2SO4 solution. By utilization of the 3-electrode system, the effect mechanisms of the running temperature and time on electrochemical parameters of the DMFC have been found: (1) The increasing operation temperature improves cathodic performance more significantly than that of anode; (2) the attenuation of fuel cell performance mainly comes from that of anode during the 20-h running test at 80 degrees C, resulting from the sharp drop of electrochemical active surface area of anode. More important, the new 3-electrode system has simplified the detection equipment and reduced the operating difficulty in a practical application for DMFCs, resulting in its portability. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Synthesis of New Sulfonated Polyimide and Its Photo-Crosslinking for Polymer Electrolyte Membrane Fuel Cells

Hui Liu,Myong Hoon Lee,Jun Ho Lee 한국고분자학회 2009 Macromolecular Research Vol.17 No.10

Recurrence Season Impacts the Survival of Epithelial Ovarian Cancer Patients

Liu, Xiao-Hui,Man, Ya-Nan,Wu, Xiong-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Background: Several studies indicated that the diagnosis season affects the prognosis of some cancers, such as examples in the prostate, colon and breast. This retrospective study aimed to investigate whether the diagnosis and recurrent season impacts the prognosis of epithelial ovarian cancer patients. Methods: From January 2005 to August 2010, 161 epithelial ovarian cancer patients were analyzed and followed up until August 2013. Kaplan-Meier survival curves and the log-rank test were used to make the survival analysis. Multivariate analysis was conducted to identify independent prognostic factors. Results: The prognostic factors of overall survival in epithelial ovarian cancer patients included age, clinical stage, pathological type, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles. Moreover, clinical stage, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles also impacted the progression-free survival of epithelial ovarian cancer patients. The diagnosis season did not have a significantly relationship with the survival of operable epithelial ovarian cancer patients. Median overall survival of patients with recurrent month from April to November was 47 months, which was longer (P < 0.001) than that of patients with recurrence month from December to March (19 months). Median progression-free survival of patients with recurrence month from April to November and December to March was 20 and 8 months, respectively (P < 0.001). Conclusion: The recurrence season impacts the survival of epithelial ovarian cancer patients. However, the diagnosed season does not appear to exert a significant influence.

Genome-Wide Analysis of the Thioredoxin Gene Family in Gossypium hirsutum L. and the Role of the Atypical Thioredoxin Gene GhTRXL3-2 in Flowering

Liu Hui,Li Yunfei,Huang Xianzhong 한국식물학회 2021 Journal of Plant Biology Vol.64 No.5

Thioredoxin (TRX) is a highly conserved low-molecular-weight protein and a ubiquitous antioxidant enzyme that plays key role in the regulation of plant growth and development. Here, using the whole-genome sequence, we performed a systematic analysis for the TRX gene family in upland cotton (Gossypium hirsutum L.) and analyzed their structural characteristics, evolution, and expression profiles during growth and development. At least 86 GhTRX members, 40 typical and 46 atypical, were identified in the cotton genome, and they were unevenly distributed on the 26 chromosomes. Conserved domains and phylogenic tree construction classified the typical TRX gene family into seven subfamilies and the atypical TRX into nine subfamilies. An evolutionary analysis revealed that the TRX gene family underwent purification selection during evolution. In addition, an RNA-Seq analysis showed that, during vegetative and reproductive development, the differences in transcript abundance levels and organ-specific expression patterns suggest functional diversity. Biochemical assays demonstrated that the atypical TRX protein GhTRXL3-2 interacted with the cotton FLOWERING LOCUS T protein GhFT. The overexpression of GhTRXL3-2 in Arabidopsis thaliana resulted in early flowering compared with control plants. Additionally, the silencing of GhTRXL3-2 in cotton delayed maturation, suggesting that it has important roles in cotton’s flowering regulation. These results help clarify the evolution of the TRX genes and elucidate their biological functions in cotton flowering regulation.

코로나19 하의 원격교육에서 유학생 학습동기가 학습몰입도, 학습효과, 학습만족도에 미치는 영향 : 충북대학교 중국 유학생을 중심으로

LIU HUI,최영출 충북대학교 사회과학연구소 2021 사회과학연구 Vol.38 No.1

Comprehensive Analysis of Magnetization, Magnetostriction, Hysteresis and Kinematical Characteristics for Precision Magnetostrictive Actuator

Hui-Fang Liu,Jie Wang,Han-Yu Wang,Qing-Wei Shao 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.12

In order to systematically know the operating characteristics and further improve accuracy of precision magnetostrictive actuator used in precision and ultra precision machining fields, a model considering magnetization hysteresis mechanism and kinematics is established based on the domain wall magnetization essential theory. Magnetization, magnetostriction and kinematical characteristics, and the origin of hysteresis are discussed. According to input energy per unit volume of magnetostrictive materials is the sum of static magnetic energy and hysteresis loss energy, magnetization is divided into reversible and irreversible processes. Moreover, hysteresis loop is represented as an offset of irreversible magnetization relative to anhysteretic magnetization. Actuator’s model is deduced through dividing working process into four stages. Experiments show that the predicted values show good agreement with experimental data and average relative error of displacement is less than 5%. Magnetic hysteresis is derived from irreversible process in which magnetic domain cannot return back to initial distribution state completely. And hysteresis is more serious with the increasement of frequency. Research results reveal magnetization and kinematic characteristics from intrinsic physical mechanism, thus it provides a theoretical guidance for further improve the accuracy of magnetostrictive actuator and promotes the practical application of actuator in precision and ultra precision machining fields.

Nickel hydroxide/chemical vapor deposition-grown graphene/nickel hydroxide/nickel foam hybrid electrode for high performance supercapacitors

Liu, Shude,Yin, Ying,San Hui, Kwan,Hui, Kwun Nam,Lee, Su Chan,Chan Jun, Seong Elsevier 2019 ELECTROCHIMICA ACTA Vol.297 No.-

<P><B>Abstract</B></P> <P>Rational design of electrode structures has been recognized as an effective strategy to improve the electrochemical performance of electrode materials. Herein, we demonstrate an integrated electrode in which nickel hydroxide (Ni(OH)<SUB>2</SUB>) nanosheets are deposited on both sides of chemical vapor deposition-grown graphene on Ni foam, which not only effectively optimizes electrical conductivity of Ni(OH)<SUB>2</SUB>, but also accommodates the structural deformation associated with the large volume change upon cycling. The synthesized Ni(OH)<SUB>2</SUB>/graphene/Ni(OH)<SUB>2</SUB>/Ni foam electrode exhibits a high specific capacity of 991 C g<SUP>−1</SUP> at a current density of 1 A g<SUP>−1</SUP>, which is higher than the theoretical specific capacity of additive sum of Ni(OH)<SUB>2</SUB> and graphene, and retains 95.4% of the initial capacity after 5000 cycles. A hybrid supercapacitor is constructed by using Ni(OH)<SUB>2</SUB>/graphene/Ni(OH)<SUB>2</SUB>/Ni foam as the positive electrode and activated carbon on Ni foam as the negative electrode, which achieves a maximum energy density of 49.5 W h kg<SUP>−1</SUP> at a power density of 750 W kg<SUP>−1</SUP>, and excellent cycling lifespans with 89.3% retention after 10000 cycles at 10 A g<SUP>−1</SUP>.</P>

The Analysis of the Origin of Confucianism of Song Dynasty in the Confucianism of Jin Dynasty -On the Spread and Influence of the Confucianism of Song Dynasty in the Jin Dynasty

( Liu Hui ),( Shao Hanming ) 성균관대학교 유교문화연구소 2011 儒敎文化硏究(中文版) Vol.0 No.15

金代儒學的學術思想直接源自漢唐經學和宋代儒學。與漢唐經學相較, 宋學尤其是南宋理學在金代傳播范圍有限, 流傳時間也較爲短暫, 但是其對金代儒學本身的影響, 在某種意義上甚至超過了漢唐經學。《宋元學案》列有宋代90 多個學案, 其中對金代儒學産生直接的、較大影響的學派有蘇氏蜀學、二程洛學、朱熹闽學。本文將分別就三者在金代的流傳及其與金代儒學的關系作以簡要梳理, 以期對金代儒學的學術源流主要是宋學源流有一個淸晳的把握。 Lin The academic thought of the Confucianism of Jin Dynasty origins directly from the Confucian Classics of the Han Dynasty and Tang Dynasty and the Confucianism of Song Dynasty. Comparing with the Confucian Classics of the Han Dynasty and Tang Dynasty, the Confucianism of Song Dynasty, especially the Confucianism of Nan Song Dynasty is limited in the spread range and it spreads in a relatively short time, but its influence is even more than the the Confucian Classics of the Han Dynasty and Tang Dynasty. The Case Studies of Song Dynasty and Yuan Dynasty lists more than 90 cases of Song Dynasty, the schools which influence the Confucianism of Jin Dynasty directly and greatly include Shu Shi Shu Xue, Er Cheng Luo Xue and Zhu Xi Min Xue. In this paper, I will research on the spread of the above three in the Jin Dynasty and its relationship with the Confucianism of Jin Dynasty in order to get a clear understanding of the fact that the academic origin of the Confucianism of Jin Dynasty is from the origin of the Confucianism of Song Dynasty. [Article in Chinese]