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Mechanical characteristics of fused cast basalt tube encased in steel pipe for protecting steel surface

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中国有色金属学会会刊：英文版 2009年第4期19卷 935-940页

作者： jee-Seok WANG Jong-Do kim Hee-Jong YOON Division of Mechanical and Information Engineering Korea Maritime University Division of Marine System Engineering Korea Maritime University Department of Research and Development Dongdo Basalt Industry Co.Ltd

Because of the various excellent characteristics of cast basalt materials,such as,anti-corrosion,anti-wearing,good hardness,high chemical stability,of which steel may not possess,the steel-basalt composite pipes are used in severe environments for compensating the defects of *** limit of bending moment with which steel-basalt composite pipe may safely endure was calculated and the limit curvature of the composite pipe in the safe range was *** application temperature of steel-basalt pipe was examined due to a different coefficient among basalt,mortar and mild steel.

关键词：玄武岩钢管表面保护机械特性包裹熔铸化学稳定性复合管

Single-atom Pd catalyst anchored on Zr-based metal-organic polyhedra for Suzuki-Miyaura cross coupling reactions in aqueous media

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Nano Research 2021年第2期14卷 486-492页

作者： Seongsoo kim Seohyeon jee Kyung Min Choi Dong-Sik Shin Division of Chemical and Bioengineering Kangwon National UniversityGangwon-do 24341Republic of Korea Department of Chemical and Biological Engineering Sookmyung Womens University100 Cheongpa-ro 47-gilYongsan-guSeoul 04310Republic of Korea

The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting *** has been desired tofind a supporting material designed in molecular level to anchor a single-atom catalyst and provide high degree of dispersion and substrate access in aqueous ***,we prepared discrete cages of metal-organic polyhedra anchoring single Pd atom(MOP-BPY(Pd))and successfully performed a Suzuki-Miyaura cross coupling reaction with various substrates in aqueous *** was revealed that each tetrahedral cage of MOP-BPY(Pd)has 4.5 Pd atoms on average and retained its high degree of dispersion up to 3 months in *** coupling efficiencies of the Suzuki-Miyaura cross coupling reaction exhibited more than 90.0%for various substrates we have tested in the aqueous media,which is superior to those of the molecular Pd complex and metal-organic framework(MOF)anchoring Pd ***,MOP-BPY(Pd)was successfully recovered and recycled without performance degradation.

关键词： metal-organic polyhedra Suzuki-Miyaura cross coupling reaction structure characterization aqueous phase reaction high-degree of dispersion

Optimal design of auxiliary-teeth to solve circulation current reduction of permanent magnet linear synchronous motor

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Journal of Central South University 2011年第3期18卷 690-696页

作者： JANG Ki-bong kim jee-hyun AN Ho-jin kim Gyu-tak School of Mechatronics Changwon National University

A discontinuity of magnetic circuits according to the end effect is generated in the permanent magnet linear synchronous motor （PMLSM）. Due to the unbalanced back electro-motive force （EMF） and impedance produced, unbalanced current is generated. The cireulatin8 current, which is caused by a decrease in the thrust, is generated by the unbalanced current. The optimal design of auxiliary-teeth at the end of the mover was carried out to solve the unbalance of phase by using design of experiment （DOE）, and compared with the basic model through finite element analysis （FEA）. As a result, the auxiliary-teeth model compensates for the decrease of thrust caused by the unbalanced phase. Also, this model is proven to reduce the detent force by the vibration and noise of the PMLSM and copper loss caused by the circulating current.

关键词： permanent magnet linear synchronous motor auxiliary-teeth circulation current end effect thrust reduction

Counter-balancing effects of Si on C partitioning and stacking fault energy of austenite in 10Mn quenching and partitioning steel

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Journal of Materials Science & Technology 2022年第3期98卷 248-257页

作者： Dong Hwi kim jee-Hyun Kang Hojun Gwon Joo Hyun Ryu Sung-Joon kim Graduate Institute for Ferrous Technology Pohang University of Science and TechnologyPohang 37673Republic of Korea School of Materials Science and Engineering Institute of Materials TechnologyYeungnam UniversityGyeongsan 38541Republic of Korea POSCO Technical Research Laboratories POSCOGwangyang 57807Republic of Korea

Silicon is an essential alloying element in quenching and partitioning(Q&P)steels,because it is known to suppress carbide precipitation during partitioning step and promote carbon partitioning to stabilize *** 2 wt%Si was added to 10Mn-2Al-0.2C steel,the size and fraction of the carbides formed during partitioning became smaller than in the Si-free ***,the suppression of carbide formation promoted C partitioning into austenite as ***,austenite stability was always lower with Si under the equivalent partitioning condition because Si effectively decreased the stacking fault energy of *** partitioning progressed,the both yield and tensile strengths of the Si-added steel exceeded that of the Si-free steel with the similar ductility *** was because Si was an effective solid solution strengthener,and the austenite in the Si-added steel exhibited the appropriate stability to gradually transform into martensite throughout the *** resulting strengthening effect compensated for the softening caused by martensite ***,strain hardening rate decreased continuously throughout deformation,which resulted in high tensile strength and ductility.

关键词： Steels Q&P steel Silicon Austenite stability Tensile deformation Stacking fault energy Medium Mn steel

Influence of Vanadium Content on Hot Deformation Behavior of Low-Carbon Boron Microalloyed Steel

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Acta Metallurgica Sinica(English Letters) 2020年第5期33卷 705-715页

作者： Kwang-Su kim Lin-Xiu Du Hyo-sung Choe Tae-hyong Lee Gyong-Chol Lee Department of Materials Science and Engineering Kim Chaek University of TechnologyPyongyang 999093Democratic People’s Republic of Korea State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

Single-pass compression tests were performed to investigate the hot deformation behavior of low-carbon boron microalloyed steel containing three various vanadium contents at 900-1100℃and strain rate of 0.01-10 s-1 using the MMS-300 thermal mechanical *** flow stress curves of investigated steels were obtained under the different deformation conditions,and the effects of the deformation temperature and strain rate on the flow stress were *** characteristic points of flow stress were obtained from the stress dependence of strain hardening rate;the activation energy of investigated steels was determined by the regression analysis;the flow stress constitutive equations were developed;the effect of vanadium content on the flow stress and dynamic recrystallization(DRX)was *** result showed that the flow stress and activation energy(3-6.5 kJ mol-1)of the steel containing 0.18 wt%V were significantly higher than those of the steels with0.042 wt%and 0.086 wt%V,which was related to the increase in solute drag and precipitation effects for higher vanadium *** analysis showed that the addition of vanadium can delay the initiation and the rate of DRX.

关键词： Boron microalloyed steel Vanadium Flow stress Hot deformation Dynamic recrystallization

Imidazole linker‐induced covalent triazine framework-ZIF hybrids for confined hollow carbon super‐heterostructures toward a long‐life supercapacitor

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Carbon Energy 2023年第10期5卷 25-39页

作者： Madagonda MVadiyar Ji‐Young kim jee‐Hwan Bae Kyung‐Wan Nam Department of Energy and Materials Engineering Dongguk UniversitySeoulSouth Korea Advanced Analysis&Data Center Korea Institute of Science and Technology(KIST)SeoulSouth Korea Advanced Energy and Electronic Materials Research Center Dongguk UniversitySeoulSouth Korea

Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ordered structure and toxic superacid that dissolves or destabilizes the metal *** solve this problem,herein,we report a straightforward two-step pathway for the covalent hybridization of disordered CTF(d–CTF)–ZIF composites via preincorporation of an imidazole(IM)linker into ordered CTFs,followed by the imidazole-site-specific covalent growth of *** carbonization of these synthesized d–CTF−IM−ZIF hybrids results in unique hollow carbon super-heterostructures with ultrahigh nitrogen content(>18.6%),high specific surface area(1663m^(2)g^(−1)),and beneficial trace metal(Co/Zn NPs)contents for promoting the redox *** proof of concept,the obtained carbon super-heterostructure(Co–Zn–NC_(SNH)–800)is used as a positive electrode in an asymmetric supercapacitor,demonstrating a remarkable energy density of 61Wh kg^(−1)and extraordinary cyclic stability of 97%retention after 30,000 cycles at the cell *** presynthetic modifications of CTF and their covalent hybridization with ZIF crystals pave the way toward new design strategies for synthesizing functional porous carbon materials for promising energy applications.

关键词： asymmetric supercapacitor defective covalent triazine frameworks hollow carbon superheterostructures linker defect

Clinical features and literature review related to the material differences in thread rhinoplasty:Two case reports

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World Journal of Clinical Cases 2021年第31期9卷 9635-9644页

作者： Da Woon Lee Heongrae Ryu Si-hyong Jang Jun Hyuk kim Department of Plastic and Reconstructive Surgery College of MedicineSoonchunhyang UniversityCheonan 31151Chungcheongnam-doSouth Korea Department of Pathology College of MedicineSoonchunhyang UniversityCheonan 31151Chungcheongnam-doSouth Korea

BACKGROUND Thread rhinoplasty can trigger a reaction to thread material,which is a foreign *** compared clinical features induced by absorbable and non-absorbable threads following thread *** SUMMARY Two patients who underwent different thread materials showed different clinical courses and different Hounsfield unit(HU)values in computed *** with absorbable thread showed high HU values similar to a metallic material,and the HU value of inflammation was similar to vascular tissues with a lot of water(250).In the intraoperative field,absorbable thread materials and micro-abscesses were *** contrast,in the case of a non-absorbable thread,an object presumed to be thread was seen on the computed tomography(CT),and the HU value of inflammatory tissues was less than *** both patients,post-operative HU decreased to less than 100 and the clinical course *** both cases,histopathologic findings revealed foreign body granuloma associated with *** Absorbable threads were more aggressive and are more easily detected on CT.

关键词： Thread rhinoplasty Polydioxanone Polyprophylene Hounsfield unit Computed tomography

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

Uncontrolled high blood pressure under total intravenous anesthesia with propofol and remifentanil:A case report

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World Journal of Clinical Cases 2022年第26期10卷 9411-9416页

作者： Min Jung Jang jee Hee kim Hae Jeong Jeong Anesthesiology and Pain Medicine National Cancer CenterGoyang 10408South Korea

BACKGROUND Although propofol generally reduces blood pressure,rarely,it causes ***,the mechanism by which propofol increases blood pressure has not been established,and so far,there are only a few reported *** SUMMARY A 46-year-old woman,diagnosed with thyroid cancer,was administered general anesthesia with propofol and remifentanil for a thyroid *** increase in the concentrations of intravenous anesthetics further increased her blood *** blood pressure remained stable when anesthesia was maintained with sevoflurane and remifentanil after the interruption of propofol *** We concluded that propofol administration was the cause of increased blood pressure.

关键词： Anesthesia Intravenous Hypertension Propofol Remifentanil Tachycardia Case report