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.

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LIU HUI,이상근 한국경영정보학회 2023 한국경영정보학회 학술대회논문집 Vol.2023 No.06

Facile Synthesis of Microsphere Copper Cobalt Carbonate Hydroxides Electrode for Asymmetric Supercapacitor

Liu, S.,Hui, K.S.,Hui, K.N.,Jadhav, V.V.,Xia, Q.X.,Yun, J.M.,Cho, Y.R.,Mane, R.S.,Kim, K.H. Pergamon Press 2016 ELECTROCHIMICA ACTA Vol.188 No.-

Porous microspheres copper cobalt carbonate hydroxides (Cu<SUB>x</SUB>Co<SUB>2@?x</SUB>CH) pseudocapacitive electrode material comprised of nanoplates via a facile hydrothermal method were presented. Significantly, the crystalline structure, morphology and electrochemical performance of the Cu<SUB>x</SUB>Co<SUB>2@?x</SUB>CH can be readily manipulated by varying the Cu/Co molar ratios. Among various stoichiometries of Cu<SUB>x</SUB>Co<SUB>2@?x</SUB>CH porous microspheres studied, Cu<SUB>1.79</SUB>Co<SUB>0.21</SUB>CH consisted of nanoplates with a mean thickness of @?35nm showed a high specific capacitance of 789Fg<SUP>@?1</SUP> at a current destiny of 1Ag<SUP>@?1</SUP> and good rate ability. Furthermore, the optimized Cu<SUB>1.79</SUB>Co<SUB>0.21</SUB>CH electrode also exhibited remarkable high cycling stability, ca 77.5% after 3000 charge/discharge cycles at current density of 5Ag<SUP>@?1</SUP>. An asymmetric device was constructed from optimized Cu<SUB>1.79</SUB>Co<SUB>0.21</SUB>CH materials on nickel foam (NF) as cathode electrode and graphene on NF as anode electrode in a 6M KOH electrolyte. The asymmetric Cu<SUB>1.79</SUB>Co<SUB>0.21</SUB>CH/NF//graphene/NF supercapacitor device delivered a specific capacitance of 60.5Fg<SUP>@?1</SUP> in a potential range of 0@?1.6V. A high energy density of 21.5Whkg<SUP>@?1</SUP> was achieved at the power density of 200Wkg<SUP>@?1</SUP>. More significantly, the designed device exhibited excellent cycling stability with 73.3% capacity retention after 5000 cycles.

Effects of Androgen Receptor Overexpression on Chondrogenic Ability of Rabbit Articular Chondrocytes

Hui Liu,Shoumei Xuan,Zhoujing Zhang,Kuang Gu,Duohong Zou,Jiacai He,Yong Zhou 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.4

Background: The role of sex hormones and their receptors has drawn much attention in the process of cartilage regeneration. This study aimed to investigate the effect of androgen receptor (AR) on the chondrogenic ability of articular chondrocytes and the related mechanism. Methods: Articular chondrocytes were isolated, cultured, identified by toluidine blue staining and then transduced with lentivirus carrying the AR gene. The cell viability was determined using Cell Counting Kit-8, and cell apoptosis was assessed by flow cytometry analysis. The effects of AR overexpression on the expression of cartilage-specific proteins and some signalling molecules were evaluated by real-time PCR and Western blotting. Using 24 New Zealand rabbits, the regeneration of rabbit articular cartilage defects was further investigated in vivo and evaluated histologically. Results: The overexpression of AR significantly reduced the apoptosis rate of chondrocytes but did not affect their proliferation. The overexpression of AR also promoted the expression of Sry-related HMG box 9, collagen II and aggrecan, decreased the expression of matrix metalloproteinase-13, and downregulated p-S6 and RICTOR. The experimental group with AR-overexpressing chondrocytes exhibited superior regeneration of cartilage defects. Conclusion: AR overexpression can maintain the phenotype of chondrocytes and promote chondrogenesis in vitro and in vivo. mTOR-related signalling was inhibited. Background: The role of sex hormones and their receptors has drawn much attention in the process of cartilage regeneration. This study aimed to investigate the effect of androgen receptor (AR) on the chondrogenic ability of articular chondrocytes and the related mechanism. Methods: Articular chondrocytes were isolated, cultured, identified by toluidine blue staining and then transduced with lentivirus carrying the AR gene. The cell viability was determined using Cell Counting Kit-8, and cell apoptosis was assessed by flow cytometry analysis. The effects of AR overexpression on the expression of cartilage-specific proteins and some signalling molecules were evaluated by real-time PCR and Western blotting. Using 24 New Zealand rabbits, the regeneration of rabbit articular cartilage defects was further investigated in vivo and evaluated histologically. Results: The overexpression of AR significantly reduced the apoptosis rate of chondrocytes but did not affect their proliferation. The overexpression of AR also promoted the expression of Sry-related HMG box 9, collagen II and aggrecan, decreased the expression of matrix metalloproteinase-13, and downregulated p-S6 and RICTOR. The experimental group with AR-overexpressing chondrocytes exhibited superior regeneration of cartilage defects. Conclusion: AR overexpression can maintain the phenotype of chondrocytes and promote chondrogenesis in vitro and in vivo. mTOR-related signalling was inhibited.

Natural fracture prediction in Keshen 2 ultra-deep tight gas reservoir based on R/S analysis, Kuqa Depression, Tarim Basin

Hui Zhang,Wei Ju,Guoqing Yin,Xinyu Liu,Zhimin Wang,Sijia Liu,Ke Wang,Hui Yang,Ke Xu,Wenbo Luan 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.4

Within ultra-deep tight sandstone gas reservoirs, natural fractures indicate significant effects on reservoir performance because they can serve as storage spaces for hydrocarbons and improve the permeability. Accurate prediction of natural fractures in ultra-deep reservoirs is critical to the exploration and development of tight gas in Keshen 2 Block of Kuqa Depression. In this study, several conventional logs are selected and the R/S analysis method is introduced to predict the development and distribution of natural fractures in ultra-deep tight sandstone reservoirs. Fracture development coefficient Q is calculated based on the second derivatives of lg(R/S) function and corresponding weight of each log parameter, which matches well with linear fracture density measured from image logs. There is a positive correlation between parameter Q and fracture density, higher Q values usually indicate larger fracture density. Factors causing mismatches between calculated parameter Q and fracture density are also analyzed. Fracture dip angle, fracture filling condition, vertical resolution of logs, multiple interpretations of conventional logs, and lateral detection difference between image and conventional logs may contribute to generate those false appearances. The results in this study are expected to provide new geological references for the exploration and development of ultra-deep tight gas in Keshen 2 Block of Kuqa Depression.

Effects of dietary supplementation with Pediococcus acidilactici ZPA017 on reproductive performance, fecal microbial flora and serum indices in sows during late gestation and lactation

Liu, Hui,Wang, Sixin,Zhang, Dongyan,Wang, Jing,Zhang, Wei,Wang, Yamin,Ji, Haifeng Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.1

Objective: This study was conducted to determine the effects of dietary supplementation with Pediococcus acidilactici (P. acidilactici) ZPA017 as a probiotic on reproductive performance, fecal microbial flora and serum indices in sows during late gestation and lactation. Methods: A total of 94 sows (Large White×Yorkshire, average 4.50 parities) were randomly allotted to two dietary treatments: control diet and the diet supplemented with P. acidilactici ZPA017 (2.40×10⁹ colony-forming unit/kg of diets). The study started at d 90 of gestation and conducted until d 28 of lactation. Results: Compared to sows fed the control diet, supplementation of P. acidilactici ZPA017 increased the number of weaning piglets, weaning weight of litter and piglets, survival rate of piglets at weaning (p<0.05), and decreased diarrhea rate of piglets in lactation (p<0.05). Dietary P. acidilactici ZPA017 increased fecal Lactobacillus populations (p = 0.030) and reduced fecal Escherichia coli and Staphylococcus aureus populations (p<0.05) of sows at weaning. Moreover, the supplementation of P. acidilactici ZPA017 increased serum concentrations of immunoglobulin G, immunoglobulin A and total protein (p<0.05), while decreased serum haptoglobin concentration and alanine aminotransferase activity (p<0.05) of sows at weaning. Conclusion: Administration of P. acidilactici ZPA017 in diets during late gestation and lactation had positive effects on the reproductive performance, intestinal microflora balance and immunity of sows.

The High Expressed Serum Soluble Neural Cell Adhesion Molecule, a High Risk Factor Indicating Hepatic Encephalopathy in Hepatocelular Carcinoma Patients

Liu, Tian-Hua,Guo, Kun,Liu, Ri-Qiang,Zhang, Shu,Huang, Zhuo-Hui,Liu, Yin-Kun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Objective: To investigate whether the expression of serum soluble neural cell adhesion molecule (sNCAM) is associated with hepatic encephalopathy (HE) in hepatocelular carcinoma (HCC) patients. Materials and Methods: The Oncomine Cancer Microarray database was used to determine the clinical relevance of NCAM expression in different kinds of human cancers. Sera from 75 HCC cases enrolled in this study were assessed for expression of sNCAM by enzyme linked immunosorbent assay (ELISA). Results: Dependent on the Oncomine Cancer Microarray database analysis, NCAM was down regulated in 10 different kinds of cancer, like bladder cancer, brain and central nervous system cancer, while up-regulated in lung cancer, uterine corpus leiomyoma and sarcoma, compared to normal groups. Puzzlingly, NCAM expression demonstrated no significant difference between normal and HCC groups. However, we found by quantitative ELISA that the level of sNCAM in sera from HCC patients with HE ($347.4{\pm}151.9ng/ml$) was significantly more up-regulated than that in HCC patients without HE ($260.3{\pm}104.2ng/ml$), the p-value being 0.008. sNCAM may be an important risk factor of HE in HCC patients, the correlation coefficients was 0.278 (P<0.05) on rank correlation analysis. Conclusions: This study highlights that up-regulated level of serum sNCAM is associated with HE in HCC patients and suggests that the high expression can be used as an indicator.

Synthesis and Characterization of Novel Photosensitive Sulfonated Polyimides for Fuel Cell Application

Hui Liu,Xiang Dan Li,Zhenxin Zhong,Guang Jin,이명훈 한국고분자학회 2004 한국고분자학회 학술대회 연구논문 초록집 Vol.29 No.2

An asymmetric supercapacitor with excellent cycling performance realized by hierarchical porous NiGa₂O₄ nanosheets

Liu, Shude,Hui, Kwan San,Hui, Kwun Nam,Li, Hai-Feng,Ng, Kar Wei,Xu, Jincheng,Tang, Zikang,Jun, Seong Chan The Royal Society of Chemistry 2017 Journal of Materials Chemistry A Vol.5 No.36

<▼1><P>Cycling stability of an asymmetric supercapacitor is enhanced using hierarchical porous NiGa2O4 nanosheets as cathode electrode.</P></▼1><▼2><P>Rational design of the composition and electrochemically favorable structural configuration of electrode materials are highly required to develop high-performance supercapacitors. Here, we report our findings on the design of interconnected NiGa2O4 nanosheets as advanced cathode electrodes for supercapacitors. Rietveld refinement analysis demonstrates that the incorporation of Ga into NiO leads to a larger cubic lattice parameter that promotes faster charge-transfer kinetics, enabling significantly improved electrochemical performance. The NiGa2O4 electrode delivers a specific capacitance of 1508 F g<SUP>−1</SUP> at a current density of 1 A g<SUP>−1</SUP> with a capacitance retention of 63.7% at 20 A g<SUP>−1</SUP>, together with excellent cycling stability after 10 000 charge–discharge cycles (capacitance retention of 102.4%). An asymmetric supercapacitor device was assembled by using NiGa2O4 and Fe2O3 as cathode and anode electrodes, respectively. The ASC delivers a high energy density of 45.2 W h kg<SUP>−1</SUP> at a power density of 1600 W kg<SUP>−1</SUP> with exceptional cycling stability (94.3% cell capacitance retention after 10 000 cycles). These results suggest that NiGa2O4 can serve as a new class cathode material for advanced electrochemical energy storage applications.</P></▼2>