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Enhancement of Au–Ag–Te contents in tellurium-bearing ore minerals via bioleaching

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 262-270页

作者： Nag-Choul Choi Kang Hee Cho Bong ju Kim Soonjae Lee Cheon Young park Department of Rural Systems Engineering Seoul National University Department of Earth and Environmental Sciences Korea University Department of Energy and Resource Engineering Chosun University

The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals(hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au–Ag–Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.

关键词： tellurium-bearing mineral bioleaching adaptation Au–Ag–Te Acidithiobacillus ferrooxidans

Leader-following consensus criteria for multi-agent systems with time-varying delays and switching interconnection topologies

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Chinese Physics B 2012年第11期21卷 144-153页

We consider multi-agent systems with time-varying delays and switching interconnection topologies. By con- structing a suitable Lyapunov-Krasovskii functional and using the reciprocally convex approach, new delay-dependent consensus criteria for the systems are established in terms of linear matrix inequalities （LMIs）, which can be easily solved by using various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed methods.

关键词： consensus multi-agent systems time delay Lyapunov method

State estimation for neural neutral-type networks with mixed time-varying delays and Markovian jumping parameters

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Chinese Physics B 2012年第10期21卷 29-37页

作者： S.Lakshmanan ju H.park H.Y.jung P.Balasubramaniam Department of Information and Communication Engineering/Electrical Engineering Yeungnam University214-1 Dae-DongKyongsan 712-749Republic of Korea Department of Mathematics Gandhigram Rural Institute-Deemed UniversityGandhigram - 624 302TamilnaduIndia

This paper is concerned with a delay-dependent state estimator for neutral-type neural networks with mixed timevarying delays and Markovian jumping *** addressed neural networks have a finite number of modes,and the modes may jump from one to another according to a Markov *** construction of a suitable Lyapunov-Krasovskii functional,a delay-dependent condition is developed to estimate the neuron states through available output measurements such that the estimation error system is globally asymptotically stable in a mean *** criterion is formulated in terms of a set of linear matrix inequalities（LMIs）,which can be checked efficiently by use of some standard numerical packages.

关键词： neural networks state estimation neutral delay Markovian jumping parameters

Design and evaluation of nicorandil extended-release tablet

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Asian Journal of Pharmaceutical Sciences 2015年第2期10卷 108-113页

作者： ju-Young Kim Chun-Woong park Beom-Jin Lee Eun-Seok park Yun-Seok Rhee College of Pharmacy Woosuk UniversityWanju-gun 565-701Republic of Korea College of Pharmacy Chungbuk National UniversityCheongju 361-763Republic of Korea College of Pharmacy Ajou UniversitySuwon 443-749Republic of Korea School of Pharmacy Sungkyunkwan UniversitySuwon 440-746Republic of Korea College of Pharmacy and Research Institute of Pharmaceutical Sciences Gyeongsang National UniversityJinju 660-701Republic of Korea

The aim of this study was to design and evaluate extended-release formulations of a model drug,nicorandil,in order to achieve the desired steady-state plasma concentration of drug in *** was employed to estimate optimum dissolution and absorption rate of *** dissolution test was employed using pH 1.2,4.0,6.8 buffer solution,or water,to measure the in vitro release behaviors of nicorandil formulations.A single dose(15 mg)of each formulation was orally administered to four beagle dogs under fasted conditions,and the pharmacokinetic parameters were *** in vitro/in vivo relationship of the extended-release formulation was confirmed using in vitro dissolution profiles and plasma concentrations of drug in beagle *** was released completely within 30 min from the immediate-release tablets and released for 24 h from the extended-release *** nicorandil plasma concentration could be modified by adjusting the drug release rate from the extended-release *** release rate of nicorandil was the rate-limiting step in the overall absorption of drug from the extendedrelease *** results highlight the potential of a nicorandil extended-release formulation in the treatment of angina pectoris.

关键词： Nicorandil In vitro In vivo Pharmacokinetic Extended-release

Super-resolution morphological dissemination of intercalating dye in single DNA molecules via binding activated localization microscopy

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Chinese Chemical Letters 2018年第3期29卷 505-508页

作者： Guenyoung park Suresh Kumar Chakkarapani Soyeong ju Sujin Ahn seong Ho Kang Department of Chemistry Graduate School Kyung Hee University Department of Applied Chemistry and Institute of Natural Sciences Kyung Hee University

Fluorescent dye （YOYO-I） intercalated with single DNA molecules were investigated via bindingactivated localization microscopy （BALM） at sub-diffraction limit resolutions. Various dye-to-DNA base pair （bp） ratios were imaged using the blinking property of YOYO-1 dye under optimum BALM switching buffer conditions. Individual DNA molecules exhibited regular/irregular intercalating phenomena with respect to dye-to-DNA bp ratio. The acquired images were reconstructed into super-resolution images by applying a Gaussian fit to the centroid of the point spread function. The YOYO-1 intercalated with λ-DNA possessed a non-homogeneous region due to the different binding modes of YOYO-1 with λ-DNA. Each binding mode was imaged at the sub-diffraction limit super-resolution. The distance between homogenously localized intercalating dyes within the DNA molecules was measured to be 34nm （n= 10; dye：DNAbp= 1：100） without photocleavage in 50mmol/L β-mercaptoethylamine buffer. The results were similar to those of the theoretical values without photocleavage in the base pairs of single DNA molecules below the diffraction limit. The results paved the way for an in-depth microscopic analysis of molecular variation with single λ-DNA molecules. With this method, it should be possible to analyze the exact base pair breakdown during various stages of cell apoptosis.

关键词： λ-DNA Intercalating dye Morphological dissemination Sub-diffraction limit resolution Binding-activated localization microscopy

ntestinal Duplication Cyst Misdiagnosed as Meckel＇s Diverticulum

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Chinese Medical Journal 2016年第2期129卷 235-236页

作者： Yee-Suk Kim Donn-ju Kim Seung-Uk Bang jun-Jae park Department of Anesthesiology and Pain Medicine College of Medicine The Catholic University of Korea Seoul Republic of Korea Department of Surgery College of Medicine and Medical Research Institute The Chungbuk National University Chungbuk Republic of Korea

An intestinal duplication cyst is a very rare congenital anomaly, with symptoms including abdominal pain, abdominal distention, intestinal bleeding, and hematochezia. Hematochezia can be caused by ectopic gastric mucosa, although there are other causes of infantile hematochezia; hence, an intestinal duplication cyst can be misdiagnosed as bowel intussusception or Meckel＇s diverticulum. Here, a case of an intestinal duplication cyst that was misdiagnosed as Meckel＇s diverticulum is reported.

关键词： Duplication Cyst Gastrointestinal Hemorrhage Meckel's Diverticulum

Chorioretinal response to intravitreal aflibercept injection in acute central serous chorioretinopathy

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International Journal of Ophthalmology(English edition) 2019年第12期12卷 1865-1871页

作者： Byung ju jung Kook Lee Jin Hyung park Jae Hyung Lee Department of Ophthalmology and Visual Science Seoul St.Mary’s Hospital College of Medicine the Catholic University of Korea

AIM: To evaluate chorioretinal responses to intravitreal aflibercept injection(IAI) in patients with acute central serous chorioretinopathy(CSC). METHODS: Seventy-one eyes from 71 patients with symptomatic CSC for less than six months were included. Thirty-five eyes received a single IAI and 36 eyes were observed without treatment. Best-corrected visual acuity(BCVA), central subfield foveal thickness(CSFT), and subfoveal choroidal thickness(SFCT) were assessed at baseline and at 1, 2, and 3 mo. RESULTS: The mean SFCT in the IAI group decreased at 1 mo, rebounded at 2 mo and remained stable at 3 mo compared to the baseline, while significant change was not noted in the observation group. The mean CSFT decreased significantly during the 3-month study period in both groups, and was significantly lower in the IAI group at 1 mo(P<0.001). A rebound of CSFT between 1 and 2 mo was noted in 14 eyes(40.0%) in the IAI group and in 1 eye(2.8%) in the observation group(P<0.001). The significant visual improvement was achieved from 1 mo in the IAI group, and from 2 mo in the observation group. The rate of complete absorption of subretinal fluid at 3 mo did not differ between the two groups.(45.7% vs 41.7%, P=0.813). CONCLUSION: A single IAI for acute CSC induce a transient decrease in SFCT and CSFT, which implies that IAI may have a pharmacological effect on the underlying hyperpermeable choroid in acute CSC.

关键词： aflibercept acute central serous chorioretinopathy anti-vascular endothelial growth factor choroidal hyperpermeability choroidal thickness

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

A feasible route to produce 1.1 GPa ferritic-based low-Mn lightweight steels with ductility of 47%

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Journal of Materials Science & Technology 2022年第22期117卷 225-237页

作者： Kwang Kyu Ko Hyo ju Bae Eun Hye park Hyeon-Uk Jeong Hyoung Seok park Jae Seok Jeong jung Gi Kim Hyokyung Sung Nokeun park Jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea School of Materials Science and Engineering Yeungnam UniversityGyeongbuk 38541South Korea Materials Research Team R&D Hyundai MobisYongin 16891South Korea Materials Technology Development Team Doosan Heavy Industries&ConstructionChangwon 51711South Korea

High- and medium-Mn (H/M-Mn) base lightweight steels are a class of ultrastrong structural materials with high ductility compared to their low-Mn counterparts with low strength and poor ***, producing these H/M-Mn materials requires the advanced or high-tech manufacturing techniques, which can unavoidably provoke labor and cost concerns. Herein, we have developed a facilestrategy that circumvents the strength–ductility trade-off in low-Mn ferritic lightweight steels, by employing low-temperature tempering-induced partitioning (LTP). This LTP treatment affords a typical Fe-2.8Mn-5.7Al-0.3C (wt.%) steel with a heterogeneous size-distribution of metastable austenite embeddedin a ferrite matrix for partitioning more carbon into smaller austenite grains than into the larger austenite ones. This size-dependent partitioning results in slip plane spacing modification and lattice strain,which act through dislocation engineering. We ascribe the simultaneous improvement in strength andtotal elongation to both the size-dependent dislocation movement in austenite grains and the controlleddeformation-induced martensitic transformation. The low-carbon-partitioned large austenite grains increase the strength and ductility as a consequence of the combined martensitic transformation andhigh dislocation density-induced hardening and by interface strengthening. Additionally, high-carbonpartitioned small austenite grains enhance the strength and ductility by planar dislocation glide (inthe low strain regime) and by cross-slipping and delayed martensitic transformation (in the high strainregime). The concept of size-dependent dislocation engineering may provide different pathways for developing a wide range of heterogeneous-structured low-Mn lightweight steels, suggesting that LTP maybe desirable for broad industrial applications at an economic cost.

关键词： Low-Mn lightweight steel Carbon partitioning Metastable austenite Dislocation movement