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Microstructural characteristics and low-cycle fatigue properties of AZ91 and AZ91-Ca-Y alloys extruded at different temperatures

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Journal of Magnesium and Alloys 2023年第3期11卷 892-902页

作者： Ye Jin kim Young Min kim jun Ho Bae Soo-hyun Joo Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Engineering Dankook UniversityCheonan 31116Republic of Korea

The commercial AZ91 alloy and nonflammable SEN9(AZ91-0.3Ca-0.2Y,wt%)alloy are extruded at 300°C and 400°*** microstructure,tensile and compressive properties,and low-cycle fatigue(LCF)properties are investigated,with particular focus on the influence of the extrusion *** the AZ91 and SEN9 materials extruded at 300°C(300-materials),numerous fine Mg_(17)Al_(12)particles are inhomogeneously distributed owing to localized dynamic precipitation during extrusion,unlike those extruded at 400°C(400-materials).These fine particles suppress the coarsening of recrystallized grains,decreasing the average grain size of *** the four extruded materials have considerably different microstructures,the difference in their tensile yield strengths is insignificant because strong grain-boundary hardening and precipitation hardening effects in 300-materials are offset almost completely by a strong texture hardening effect in ***,owing to their finer grains and weaker texture,300-materials have higher compressive yield strengths *** the LCF tests,{10-12}twinning is activated at lower stresses in 400-materials than in *** the fatigue damage accumulated per cycle is smaller in 400-materials,they have longer fatigue lives than those of 300-materials.A fatigue life prediction model for the investigated materials is established on the basis of the relationship between the total strain energy density(ΔW_(t))and the number of cycles to fatigue failure(N_(f)),and it is expressed through a simple equation(ΔW_(t)=10·N_(f)-0.59).This model enables fatigue life prediction of both the investigated alloys regardless of the extrusion temperature and strain amplitude.

关键词： AZ91-Ca-Y Extrusion temperature Microstructure Low-cycle fatigue Fatigue life prediction model

Below-ground growth characteristics of 13-year-old Pinus densiflora on different contour conditions in a post-fire plantation in Samcheuk,Korea

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Journal of Forestry Research 2017年第5期28卷 1007-1018页

作者： Do-hyun kim Sung-jun Na Sea-hyun kim Ewane Basil Ewane Dae-Bong Kang Do-hyung Lee Department of Forest Resources Yeungnam University Department of Forest Genetic Resources National Institute of Forest Science

We estimated the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions by comparing and analyzing the vertical and horizontal distributions of below-ground roots on each contour. The main roots at the south-facing slope (SS) developed in a long and straight form, and those on the north-facing slope (NS) in a twisted form. The side roots developed more than the main roots on the Ridge. The depth of taproots decreased in the following order: SS > NS > Ridge. The roots on the SS developed in a pile-form root structure whereas those in the Ridge and NS developed concentrically near the root collar. The amount of root development decreased in the following order: SS > NS > Ridge. The ratio of fine roots from the whole-root development decreased in the following order: Ridge > SS > NS. These results can guide considerations of growth differences according to the planting contour conditions for future establishment of P. densiflora artificial plantations.

关键词： Pinus densiflora Growth characteristics Contour conditions Post-fire plantation Wildfire Restoration Soil depth

Obesity and novel management of inflammatory bowel disease

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World Journal of Gastroenterology 2023年第12期29卷 1779-1794页

作者： Jee hyun kim Chang-Myung Oh jun Hwan Yoo Department of Gastroenterology CHA Bundang Medical CenterCHA University School of MedicineSeongnam 13496South Korea Department of Biomedical Science and Engineering Gwangju Institute of Science and TechnologyGwangju 62465South Korea Institute of Basic Medical Sciences CHA University School of MedicineSeongnam 13496South Korea

Obesity is prevalent within the inflammatory bowel disease(IBD)population,particularly in newly developed *** epidemiological studies have suggested that 15%-40%of IBD patients are obese,and there is a potential role of obesity in the pathogenesis of *** dysfunction of mesenteric fat worsens the inflammatory course of Crohn’s disease and may induce formation of strictures or ***,obesity may affect the disease course or treatment response of *** the increasing data supporting the pathophysiologic and epidemiologic relationship between obesity and IBD,obesity control is being suggested as a novel management for ***,this review aimed to describe the influence of obesity on the outcomes of IBD treatment and to present the current status of pharmacologic or surgical anti-obesity treatments in IBD patients.

关键词： Obesity Inflammatory bowel disease Crohn’s disease Ulcerative colitis

Effect of Doubling the Ensemble Size on the Performance of Ensemble Prediction in the Warm Season Using MOGREPS Implemented at the KMA

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Advances in Atmospheric Sciences 2013年第5期30卷 1287-1302页

作者： jun Kyung KAY hyun Mee kim Young-Youn PARK Joohyung SON Department of Atmospheric Sciences Yonsei University Korea Meteorological Administration

Using the Met Office Global and Regional Ensemble Prediction System （MOGREPS） implemented at the Korea Meteorological Administration （KMA）, the effect of doubling the ensemble size on the performance of ensemble prediction in the warm season was evaluated. Because a finite ensemble size causes sampling error in the full forecast probability distribution function （PDF）, ensemble size is closely related to the efficiency of the ensemble prediction system. Prediction capability according to doubling the ensemble size was evaluated by increasing the number of ensembles from 24 to 48 in MOGREPS implemented at the KMA. The initial analysis perturbations generated by the Ensemble Transform Kalman Filter （ETKF） were integrated for 10 days from 22 May to 23 june 2009. Several statistical verification scores were used to measure the accuracy, reliability, and resolution of ensemble probabilistic forecasts for 24 and 48 ensemble member forecasts. Even though the results were not significant, the accuracy of ensemble prediction improved slightly as ensemble size increased, especially for longer forecast times in the Northern Hemisphere. While increasing the number of ensemble members resulted in a slight improvement in resolution as forecast time increased, inconsistent results were obtained for the scores assessing the reliability of ensemble prediction. The overall performance of ensemble prediction in terms of accuracy, resolution, and reliability increased slightly with ensemble size, especially for longer forecast times.

关键词： ensemble prediction ensemble size ensemble transform Kalman filter

Aqueous levels of erythropoietin in acute retinal vein occlusion with macular edema

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International Journal of Ophthalmology(English edition) 2014年第3期7卷 501-506页

作者： hyun Jin Shin hyung Chan kim jun Woong Moon Department of Ophthalmology Konkuk University Medical Center Konkuk University School of Medicine Gongdeok Seoul Eye Clinic

AIM:To investigate the aqueous erythropoietin(EPO)levels and associated factors in patients with acute retinal vein occlusion(RVO).METHODS:The aqueous EPO level was measured in patients with macular edema(ME)secondary to acute branched retinal vein occlusion(BRVO)or central retinal vein occlusion(CRVO).Aqueous fluid from cataract patients served as the *** also evaluated whether aqueous level of EPO was associated with factors such as serum EPO level,non-perfusion area,central macular thickness(CMT),and arterio-venous(AV)transit timeRESULTS:Twenty-seven RVO patients(16 BRVO,11CRVO)and 9 control subjects were enrolled in the *** aqueous EPO level(mU/mL)was higher in RVO(68.2±54.3)than that in the control subjects(12.9±5.9).More specifically,the aqueous EPO level was higher in CRVO(118.9±52.1)than that in BRVO(33.3±10.8).However,no differences were found in serum EPO levels among three *** in RVO patients had a positive correlation with the aqueous EPO level(r=0.66).Also,in terms of non-perfusion area,the aqueous EPO levels were more elevated in the ischemic subgroup than in the non-ischemic subgroup in both BRVO and ***:Aqueous EPO levels are elevated in patients with macular edema secondary to recent onset *** with CRVO have higher EPO levels than those with *** aqueous EPO level in RVO has a positive correlation with CMT and is associated with non-perfusion *** results suggest that the aqueous EPO level could be associated with retinal ischemia and may be involved in the pathogenesis of macular edema secondary to RVO.

关键词： aqueous level of erythropoietin acute retinal vein occlusion retinal ischemia macular edema

都市走廊的可持续都市主义：德克萨斯州休斯顿10号园区实证型城市设计

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景观设计学（中英文） 2017年第5期5卷 96-109页

作者：金埈铉盖伦.纽曼封赫婧杰雷米.梅里尔朴钟薰卞佳荷张健密歇根州立大学规划设计与建筑学院

该项目旨在为美国德克萨斯州休斯顿市的一处商业区制定一项综合性总体规划,该规划以可持续都市主义为设计原则。其主要设计目标是建立一个宜居且可持续的城市商业中心,以促进当地经济增长;同时推广一项街景设计指南,以提升该地块对行人... 详细信息

该项目旨在为美国德克萨斯州休斯顿市的一处商业区制定一项综合性总体规划,该规划以可持续都市主义为设计原则。其主要设计目标是建立一个宜居且可持续的城市商业中心,以促进当地经济增长;同时推广一项街景设计指南,以提升该地块对行人和骑行者的友好度。

关键词：可持续都市主义街景设计低影响开发步行和骑行友好型开发能源走廊区

Polymer donors with hydrophilic side-chains enabling efficient and thermally-stable polymer solar cells by non-halogenated solvent processing

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Nano Research Energy 2024年第1期3卷 19-29页

作者： Soodeok Seo jun-Young Park Jin Su Park Seungjin Lee Do-Yeong Choi Yun-Hi kim Bumjoon J.kim Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Department of Materials Engineering and Convergence Technology and ERI Gyeongsang National UniversityJinju 52828Republic of Korea Advanced Energy Materials Research Center Korea Research Institute of Chemical Technology(KRICT)Daejeon 34114Republic of Korea Department of Chemistry and ERI Gyeongsang National UniversityJinju 52828Republic of Korea

Polymer solar cells(PSCs)with high power conversion efficiency(PCE)and environment-friendly fabrication are the main requirements enabling their production in industrial *** the use of non-halogenated solvent processing is inevitable for the PSC fabrication,it significantly reduces the processability of polymer donors(PDS)and small-molecule acceptors(SMAs).This often results in unoptimized blend morphology and limits the device *** address this issue,hydrophilic oligoethylene glycol(OEG)side-chains are introduced into a PD(2EG)to enhance the molecular compatibility between the PD and L8-BO *** 2EG PD induces higher crystallinity and alleviates phase separation with the SMA compared to the reference PD(PM7)with hydrocarbon ***,the 2EG-based PSCs exhibit a higher PCE(15.8%)than the PM7-based PSCs(PCE=14.4%)in the ortho-xylene based ***,benefitted from the reduced phase separation and increased crystallinity of 2EG PDS,the 2EG-based PSCs show enhanced thermal stability(84%of initial PCE after 120 h heating)compared to that of the PM7-based PSCs(60%of initial PCE after 120 h heating).This study demonstrates the potential of OEG side-chain-incorporated materials in developing efficient,stable,and eco-friendly PSCs.

关键词： polymer solar cell polymer donor OEG side-chain non-halogenated solvent process side-chain engineering

Detection and pathogenesis of a novel swine H3N2 influenza virus containing three genes from the 2009 pandemic H1N1 influenza viruses in Korea in 2015

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Virologica Sinica 2016年第6期31卷 513-516页

作者： Tran Bac Le In Hong Lee Byung jun kim hyun Soo kim Sang Heui Seo Laboratory of Public Health College of Veterinary Medicine Chungnam National University Daejeon 34134 Republic of Korea.

Dear Editor,Influenza A viruses cause pandemics at an interval of approximately 10-40 years,and pigs are regarded as a＂mixing vessel＂because they are easily infected with avian and human influenza viruses（Ito et al.,1998）.According to previous studies,H3N2,H1N2,and H1N1 subtypes o（swine influenza viruses have been detected in Korean pigs （Pascua et al., 2013; kim et al., 2014; Song et al., 2007）. Moreover, a novel H3N2 influenza virus containing the matrix （34） gene from a 2009 pandemic influenza virus was detected in Korean pigs in 2013 （Pascua et al., 2013）, an H1N2 influenza virus con- taining the internal genes from a 2009 pandemic influ- enza virus was found in Korean pigs in 2014 （kim et al., 2014）, and an H1N1 influenza virus containing all genes from the classical swine influenza viruses was isolated from Korean pigs in 2007 （Song et al., 2007）.

关键词： gene Detection and pathogenesis of a novel swine H3N2 influenza virus containing three genes from the 2009 pandemic H1N1 influenza viruses in Korea in 2015

Clinical efficacy and safety of flexible ureteroscopy and percutaneous nephrolithotomy for large kidney stones:A retrospective comparative study

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World Journal of Clinical Cases 2024年第21期12卷 4483-4490页

作者： Qiu-Lian Wang jun-Qiang Liu Juan Cao jun Ding Department of Urology No.904 Hospital of Joint Logistic Support Force of PLAWuxi 214044Jiangsu ProvinceChina

BACKGROUND Renal stones ranging 20–40 mm are very common in *** no largesample clinical studies have confirmed the clinical efficacy and safety of this method,there is also a lack of comparative data with traditional *** To investigate the clinical efficacy of flexible ureteroscopy(FURS)and percutaneous nephrolithotomy(PCNL)by postoperative stone clearance and changes in soluble vascular cell adhesion molecule 1(sVCAM-1)and kidney injury molecule 1(kim-1)levels in patients with large kidney stones(>2 cm in diameter).METHODS This single-center observational study was performed at a Chinese hospital between January 1,2021,and October 30,*** 250 enrolled patients were diagnosed with large kidney stones(>2 cm)and divided into a FURS group(n=145)and a PCNL group(n=105)by the surgical *** FURS group was treated with flexible ureteroscopy and the PCNL group was treated with percutaneous *** operation time,time to palinesthesia,intraoperative blood loss,drop in hemoglobin,length of hospital stay,stone clearance rate,and complications were recorded in the two *** and postoperative serum sVCAM-1 levels,erythrocyte sedimentation rate(ESR),urine kim-1 levels,preoperative and postoperative pain visual analog scale(VAS)and Wisconsin Stone Quality of Life Questionnaire(WISQOL)scores were also *** All 250 eligible patients completed the *** were no significant differences in baseline characteristics between the two groups(P>0.05).The operation time in the FURS group was significantly greater than that in the PCNL *** time to ambulation,intraoperative blood loss,decrease in hemoglobin,and length of hospital stay were significantly lower in the FURS group than in the PCNL *** FURS group also had a significantly higher stone clearance rate and a lower incidence of postoperative *** was no significant difference in antibiotic use between the *** serum

关键词： Kidney stones Flexible ureteroscopy Percutaneous nephrolithotomy Clinical effective SCM-1 Erythrocyte sedimentation rate Kidney injury molecule 1