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Quantitative analysis of mechanical properties associated with aging treatment and microstructure in Mg-Al-Zn alloys through machine learning

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Journal of Materials Science & Technology 2022年第12期107卷 52-63页

作者： joung sik suh Byeong-Chan suh Sang Eun Lee Jun Ho Bae Byoung Gi Moon Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

The present study proposes a methodology for predicting the mechanical properties of AZ61 and AZ91alloys associated with microstructure,texture and aging parameters and estimating predictor *** this,we investigate quantitative correlations between microstructure,texture and mechanical properties of aged AZ61 and AZ91 rods through machine *** regression analysis focuses on the precipitation behavior of Mg17Al12as the main second phase of Mg-Al-Zn alloys with respect to aging *** simplify data generation,only SEM images were used to quantify the features of discontinuous and continuous *** overcome the lack of data and make the most of the measured data,we devised a method to extend the existing dataset by a factor of 9 using the mean and standard deviation of the measured *** neural networks predicted tensile and compressive yield strengths and resultant yield asymmetry with a high accuracy of over 98%using 11 predictors for a total of *** tree learning quantitatively assessed the importance of predictors in determining the mechanical properties of aged AZ61 and AZ91 rods.

关键词： Magnesium alloy Aging treatment Microstructure Mechanical properties Machine learning

Recent Progress and Development in Extrusion of Rare Earth Free Mg Alloys: A Review

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Acta Metallurgica Sinica(English Letters) 2019年第2期32卷 145-168页

作者： Shuai-Ju Meng Hui Yu Shao-Da Fan Qi-Zhi Li Sung Hyuk Park joung sik suh Young Min Kim Xiao-Long Nan Ming-Zhe Bian Fu-Xing Yin Wei-Min Zhao Bong Sun You Kwang Seon Shin School of Materials Science and Engineering Hebei University of Technology School of Materials Science and Engineering Kyungpook National University Materials Implementation Department Korea Institute of Materials Science National Key Laboratory of Shock Wave and Detonation Physics Institute of Fluid Physics China Academy of Engineering Physics School of Materials Science and Engineering Anhui University of Technology Magnesium Technology Innovation Center School of Materials Science and Engineering Seoul National University

Mg and its alloys are the lightest structural metals available and are extremely attractive for applications as lightweight components, particularly in the automobile, electronic, and aerospace industries. The global market for wrought Mg alloys has steadily expanded over the past decade. And numerous studies have been carried out to meet this increasing demand of high-performance Mg alloys. However, Mg extrusion alloys have had a very limited usage so far. To overcome existing industrial challenges, one desirable approach is the development of low-cost rare earth(RE) free Mg extrusion alloys with superior mechanical properties. This review will introduce the recent research highlights in the extrusion of Mg alloys, specifi cally focusing on low-cost RE-free Mg alloy. The results from both the literature and our previous study are summarized and critically reviewed. Several aspects of RE-free Mg extrusion alloys are described in detail:(1) novel alloying designs including Mg–Al-, Mg–Zn-, Mg–Ca-, Mg–Sn-, and Mg–Bi-based alloys,(2) advanced extrusion techniques, and(3) extrusion-related severe plastic deformation(SPD) processing. Accordingly, considering the large gap in mechanical properties between the current RE-free Mg alloys and high-performance aluminum alloys, new alloy design, processing route control, and recommendations for future research on RE-free Mg extrusion alloys are also proposed. We hope this review will not only off er insightful information regarding the extrusion of RE-free Mg alloys but also inspire the development of new Mg extrusion technologies.

关键词： Mg alloy Extrusion Rare earth free Novel processing Mechanical properties

Effect of Al addition on corrosion behavior of high-purity Mg in terms of processing history

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Journal of Magnesium and Alloys 2023年第3期11卷 851-868页

作者： Sang Kyu Woo Byeong-Chan suh Ha sik Kim Chang Dong Yim Helmholtz Zentrum Hereon Max-Planck-Straße 1Geesthacht D-21502Germany Korea Institute of Materials Science 797 Changwondae-roSeongsan-guChangwonGyeongnam 51508Republic of Korea University of Science and Technology 217 Gajeong-roYuseong-guDaejeon 34113Republic of Korea

In this study,the effects of Al addition on the corrosion behavior of pure Mg with controlled impurity contents were systematically analyzed according to the processing *** results revealed that the corrosion behavior of high-purity Mg-Al alloys is strongly related to changes in the microstructure,including theβphase and Al-Mn or Al-Fe phases,and the protectiveness of the surface film according to the Al content and processing *** the as-cast alloys,the corrosion rate increased due to the increase ofβphase as the Al content increased,but in the as-extruded alloys,the corrosion rate,which was high due to intermetallic compounds caused by impurities in the low Al alloy,decreased as the Al content increased,and then increased *** is due to the combined effect of the increase of theβphase and decrease of the impurity effect,and the increase of the dissolved Al *** results suggest that it is necessary to analyze the effect of alloying elements on the corrosion behavior of pure Mg with information concerning the impurity content and processing history.

关键词： Mg High purity Mg-Al alloys Processing history Micro-galvanic Surface film

Alpha-1-antitrypsin deficiency resulting in a hitherto unseen presentation of hepatocellular carcinoma:Polycythemia but with normal alpha fetoprotein

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World Journal of Gastroenterology 2006年第30期12卷 4906-4907页

作者： David Ryan Owen Ramachandran Sivakumar Eui-sik suh Murugiah Seevaratnam Department of Geriatric Medicine Area Q111 Queen Elizabeth Ⅱ Hospital Howlands Welwyn Garden City Hertfordshire AL7 4HQ United Kingdom

Polycythemia is a known paraneopastic manifestation of hepatoma, but only in the presence of alpha-fetopro （AFP）. We present a case of polycythemia in the absence of AFP, and suggest concurrent alpha-1-antitrypsin deficiency as the cause for breaking this rule. We also suggest a reason for the apparent constant conjunction between polycythemia and AFP in hepatoma.

关键词： Hepatoma Polycythemia Alpha 1 anti trypsin Ephrin-A Alpha-fetopro

A Study on Energy Saving Rate for Variable Speed Condition of Multistage Centrifugal Pump

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Journal of Thermal Science 2015年第6期24卷 566-573页

作者： Sang-Ho suh Rakibuzzaman Kyung-Wuk Kim Hyoung-Ho Kim In sik Yoon Min-Tae Cho Department of Mechanical Engineering Soongsil University Dooch Co. 295 Sagok-ri Jangan- Myeon Hwaseong-si Gyeonggi-do 445-942 South Korea

Centrifugal pumps are being widely used in many industrial and commercial *** of these pumps are being operated at constant speed but could provide energy savings through adjustable speed *** purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed *** this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump *** energy saving and therefore the cost saving depends on the specific duty cycle of which the machine *** cycle is the proportion of time during which a component,device and system is *** duty cycle segmented into different flow rates and weighting the average value for each segment by the interval *** system was operated at 50%or less of the pump *** input power of the system was carried out by pump characteristics curve of each operating *** energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive *** total energy consumed for constant speed drive pump was 75,770 k *** and for variable speed drive pump was 31,700 k *** total energy saving of the system was 44,070 k *** or 58.16%***,this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.

关键词： Multistage Centrifugal Pump Performance Analysis Energy saving rate SST Model Duty Cycle

Phenol content,antioxidant and tyrosinase inhibitory activity of mangrove plants in Micronesia

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Asian Pacific Journal of Tropical Medicine 2014年第7期7卷 531-535页

作者： Sung-Suk suh Jinik Hwang Mirye Park Heung-sik Park Taek-Kyun Lee South Sea Environment Research Department.Korea Institute of Ocean Science and Technology Korea South Pacific Ocean Research Center Korea Institute of Ocean Science and Technology

Objective:To find out and compare the in vitro antioxidant and tyrosinase inhibitory activities of two species of mangrove ***:Mangrove samples were harvested at the shoreline on the island of Weno,Chuuk State in *** phenol content,antioxidant activity(based on DPPH-free radical scavenging)and tyrosinase inhibitory activity in different tissues(leaves,barks and roots)of Rhizophora stylosa(***)and Sonneratia alba(***),collected from the island of ***:Total phenol content ranged from 4.87 to 11.96 mg per g of freeze dried *** highest antioxidant activity was observed in *** bark(85.5%).The highest tyrosinase inhibitory activity was found in *** ***,total phenol content and antioxidant activity were higher in methanol extracts than in aqueous ***:Taken together,the results of this study proved that mangroves can be excellent sources of antioxidant compounds.

关键词： Rhizophora stylosa Sonneratia alba Phebolics Antioxidant activity Tyrosinase inhibitory activity

A hybrid swarm population of Pinus densiflora × P. sylvestris inferred from sequence analysis of chloroplast DNA and morphological characters

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Journal of Forestry Research 2013年第1期24卷 53-60页

作者： Young Hee joung Jerry L. Hill Jung Oh Hyun Ding Mu Juchun Luo Do Hyung Lee Takayuki Kawahara Jeung Keun suh Mark S. Roh Chonnam National University School of Biological Sciences & TechnologyGwangjuKorea US Department of Agriculture Forest ServiceDorena Genetic Resource CenterWashington State UniversityPullmanWA99164USA Seoul National University College of Agriculture and Life SciencesSeoulKorea Chinese Academy of Agricultural Science Beijing Forestry University College of Resources and Environment Yeungnam University College of Natural ResourcesDepartment of Forest ResourcesGyeongsanKorea Hokkaido Research Center Forestry and Forest Products Research InstituteSapporoJapan. Dankook University School of Bio-Resource ScienceDepartment of Environment HorticultureCheonanKorea. US Department of Agriculture Agricultural Research ServiceUS National ArboretumFloral and Nursery Plants Research UnitBeltsvilleMD 20705USA.

To confirm a hybrid swarm population of Pinus densiflora × P. sylvestris in Jilin, China, we used needles and seeds from P. densiflora, P. sylvestris, and P. densiflora × P. sylvestris collected from natural stands or experimental stations to study whether shoot apex morphology of 4-year old seedlings can be correlated with the sequence of a chloroplast DNA simple sequence repeat marker （cpDNA SSRs）. Total genomic DNA was extracted and subjected to sequence analysis of the pine cpDNA SSR marker Pt15169. Results show that morphological characters from 4-year old seedlings did not correlate with sequence variants of this marker. Marker haplotypes from all P. sylvestris trees had a CTAT element that was absent from all sampled P. densiflora trees. However, both haplotype classes involving this insertion/deletion element were found in a P. densiflora × P. sylvestris population and its seedling progeny. It was concluded that the P. densiflora × P. sylvestris accessions sampled from Jilin, China resulted from bi-directional crosses, as evidenced by both species’ cpDNA haplotypes within the hybrid swarm population.

关键词： P. sylvestris var. sylvestriformis chloroplast DNA simplesequence repeat sequencing hybrid swarm population

Growth-promoting activity of Hominis Placenta extract on regenerating sciatic nerve

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Acta Pharmacologica Sinica 2006年第1期27卷 50-58页

作者： Tae-beom SEO In-sun HAN Jin-hwan YOON In-chan SEOL Yun-sik RIM Hyun-kyung JO joung-jo AN Kwon-eui HONG Young-bae SEO Dong-hee KIM Seung-kiel PARK Deok-chun YANG Uk NAMGUNG Korea Department of Oriental Medicine.Daejeon University Daejeon 300-716Korea Korea Department of Biochemistry College of Medicine Chungnam National University.Daejeon 301-130Korea Korea

Aim:Extract of Hominis Placenta (HP) has been used in oriental medicine as anagent for improving physiological *** present study was conducted toinvestigate whether HP treatment in an experimental sciatic nerve injury animalmodel produces growth-promoting effects on regenerating peripheral nerve fibersafter ***:After HP was injected into a sciatic nerve injury site,changesin protein levels were analyzed in the regenerating nerve area by Western blottingand immunofluorescence staining *** quantitative assessment of ax-onal regeneration,a retrograde tracing technique was used to identify the neu-ronal cell bodies corresponding to regenerating axons,and the extent of neuriteoutgrowth in cultured dorsal root ganglia (DRG) sensory neurons prepared fromanimals that had experienced a sciatic nerve crush injury 7d before neuron collec-tion was ***:Induction levels of axonal growth-associated protein(GAP-43) in the injured sciatic nerves were elevated by HP *** treat-ment also upregulated cell division cycle 2 (Cdc2) protein levels in the distalstump of the injured sciatic *** Cdc2 protein was detected in Schwanncells,suggesting that Cdc2 kinase activity may be involved in the growth-promot-ing activity of regenerating axons via Schwann cell *** body mea-surement by retrograde tracing indicated that HP treatment produced significantincreases in regenerating motor ***,HP treatment of cultured DRGsensory neurons significantly increased neurite arborization and ***:HP promotes the regeneration of injured sciatic axons by upregulatingthe synthesis of regeneration-related protein factors such as GAP-43 and Cdc2.

关键词： hominis placenta axonal regeneration sciatic nerve GAP-43 protein Cyclindepend kinase 2

The effect of dimiristoylphosphatidylethanol on the rotational mobility of n-(9-Anthroyloxy) stearic acid in neuronal and model membranes

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Journal of Biophysical Chemistry 2010年第3期1卷 133-140页

作者： Young-sik Park No-Soo Park Jun-Bong Seo Soo-Kyoung Bae You-Kwang kim Ki-Soo Seong Young-Jun Kim Ju-Won Park joung-Moung Shin Young-Chan Jeon In-Kyo Chung Moon-Kyoung Bae Hye-Ock Jang Il Yun 不详

The aim of this study was to provide a basis for examining the molecular mechanism for the pharmacological action of ethanol. We studied di?myristoyl?phosphatidylethanol (DMPEt)’s effects on specific locations of n-(9-anthroyloxy) palmitic acid or stearic acid (n-AS) within phos?pholipids of synaptosomal plasma membrane vesicles isolated from bovine cerebral cortex (SPMV) and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from SPMV. DMPEt increased rotational mobility (increased disordering) of hydrocarbon interior, but it decreased mobility (increased ordering) of membrane interface, in native and model membranes. The degree of rotational mobility in accordance with the carbon atom numbers of phospholipids comprising neuronal membranes was in the order at the 16, 12, 9, 6 and 2 position of aliphatic chain present in phospholipids. The sensitivity of increasing or decreasing effect of rotational mobility of hydrocarbon interior or surface region by DMPEt differed depending on the neuronal and model membranes in the descending order of SPMV, SPMVPL and SPMVTL.

关键词： Ethanol Phosphatidylethanol Fluorescence Quenching Technique Rotational Mobility Hydrocarbon Interior Membranes lnterface