检索结果-南通市图书馆

Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 1-6页

作者： Young-Keun jeong Koichi NIIHARA National Core Research Center for Hybrid Materials Solution Pusan National University Nagaoka University of Technology

A1203/5%SIC nanocomposites were fabricated by pressureless sintering using MgO as a sintering aid and then post hot-isostatic pressed （HIP）, which can subsequently break through the disadvantage of hot-pressing process. The MgO additive was able to promote the densification of the composites, but could not induce the grain growth of A1203 matrix due to the grain growth inhibition by nano-sized SiC particles. After HIP treatment, A12OJSiC nanocomposites achieved full densification and homogeneous distribution of nano-sized SiC particles. moreover, the fracture morphology of HIP treated specimens was identical with that of the hot-pressed A1203/SiC nanocomposites showing complete transgranular fracture. Consequently, high fracture strength of 1 GPa was achieved for the A1203/5%SIC nanocomposites by pressureless sintering and post HIP process.

关键词： nanocomposite pressureless sintering fracture strength

Crystal plasticity finite element simulations on extruded Mg-10Gd rod with texture gradient

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第8期12卷 3409-3430页

作者： Jaeseong Lee Dirk Steglich Youngung jeong Department of Materials Convergence and System Engineering Changwon National University25 Changwondaehak-roChangwonRepublic of Korea Helmholtz-Zentrum Hereon Institute of Material Systems ModelingD-21502 GeesthachtGermany School of Materials Science and Engineering Changwon National University25 Changwondaehak-roChangwonRepublic of Korea

The mechanical properties of an extruded Mg-10Gd sample, specifically designed for vascular stents, are crucial for predicting its behavior under service conditions. Achieving homogeneous stresses in the hoop direction, essential for characterizing vascular stents, poses challenges in experimental testing based on standard specimens featuring a reduced cross section. This study utilizes an elasto-visco-plastic self-consistent polycrystal model(ΔEVPSC) with the predominant twinning reorientation(PTR) scheme as a numerical tool, offering an alternative to mechanical testing. For verification, various mechanical experiments, such as uniaxial tension, compression, notched-bar tension, three-point bending, and C-ring compression tests, were conducted. The resulting force vs. displacement curves and textures were then compared with those based on the ΔEVPSC model. The computational model's significance is highlighted by simulation results demonstrating that the differential hardening along with a weak strength differential effect observed in the Mg-10Gd sample is a result of the interplay between micromechanical deformation mechanisms and deformation-induced texture evolution. Furthermore, the study highlights that incorporating the axisymmetric texture from the as-received material incorporating the measured texture gradient significantly improves predictive accuracy on the strength in the hoop direction. Ultimately, the findings suggest that the ΔEVPSC model can effectively predict the mechanical behavior resulting from loading scenarios that are impossible to realize experimentally, emphasizing its valuable contribution as a digital twin.

关键词： Crystal plasticity Texture Finite element C-ring Three-point bending

Newly Design Porous/Sponge Red Phosphorus@Graphene and Highly Conductive Ni2P Electrode for Asymmetric Solid State Supercapacitive Device With Excellent Performance

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2020年第2期12卷 169-184页

作者： Nazish Parveen Muhammad Hilal jeong In Han Department of Chemistry College of ScienceKing Faisal UniversityAl‑Ahsa 31982Saudi Arabia Flexible Display and Printed Electronic Lab Department of Chemical and Biochemical EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

Supercapacitors have attracted much attention in the field of electrochemical energy ***,material preparation,stability,performance as well as power density limit their applications in many ***,a sponge-like red phosphorus@graphene(rP@rGO)negative electrode and a Ni2P positive electrode were prepared using a simple one-step *** electrodes showed excellent performances(294 F g^−1 and 1526.6 F g^−1 for rP@rGO and Ni2P,respectively),which seem to be the highest among all rP@rGO-and Ni2P-based electrodes reported so *** asymmetric solid-state supercapacitor was assembled by sandwiching a gel electrolyte-soaked cellulose paper between rP@rGO and Ni2P as the negative and positive *** to other asymmetric devices,the device,which attained a high operating window of up to 1.6 V,showed high energy and power density values of 41.66 and 1200 W kg−1,*** also has an excellent cyclic stability up to 88%after various consecutive charge/discharge ***,the device could power commercial light emitting diodes and fans for 30 ***,the ease of the synthesis method and excellent performance of the prepared electrode materials mat have significant potential for energy storage applications.

关键词： Sponge red phosphorus Porous graphene Ni2P Electrode Asymmetric solid-state supercapacitor

Design-space adaptation method for multiobjective and multidisciplinary optimization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 166-189页

作者： Jongho JUNG Kwanjung YEE Shinkyu jeong Department of Aerospace Engineering Seoul National UniversitySeoul 08826Republic of Korea Department of Mechanical Engineering Kyunghee UniversityYoungin 17104Republic of Korea

This paper developed a new method that adaptively adjusts a design space by considering the actual solution distribution of a problem to overcome the conventional design-space adaptation method that assumes the solutions distribution to be a normal distribution because the distributions of solutions are rarely normal distributions for real-world *** developed method was applied to nineteen multiobjective test functions that are widely used to evaluate the characteristics and performance of optimization *** results showed that this method adapted the design space to an appropriate design space where the solution existence probability was *** optimization performance achieved using the developed method was higher than that of the conventional ***,the developed method was applied to the conceptual design of an unmanned spacecraft to confirm its validity in real-world design and multidisciplinaryoptimization *** results showed that the Pareto solutions of the developed method were superior to those of conventional ***,the optimization efficiency with the developed method was improved by more than 1.4 times over that of the conventional *** this regard,the developed method has the potential to be applied to complicated real-world optimization problems to achieve better performance and efficiency.

关键词： Multiobjective optimization Multiobjective genetic algorithm Design-space adaptation Multidisciplinary optimization Hypersonic vehicle

Rapid Establishment of Tracheal Stenosis in Pigs Using Endotracheal Tube Cuff Overpressure and Electrocautery

在线全文

学校读者我要写书评

暂无评论

Current Medical Science 2021年第2期41卷 329-335页

作者： Jin Hyoung Kim Jong Joon Ahn Yangin Jegal Soohyun bae Soon Eun Park moon Sik Jung Ju Ik Park Hee jeong Cha Yongjik Lee Taehoon Lee Division of Respiratory and Critical Care Medicine Department of Intemnal MedicineUlsan University HospitalUniversity of Ulsan College of MedicineUlsan 44033Korea Department of Anesthesiology and Pain Medicine UIsan University HospitalUniversity of Ulsan College of MedicineUlsan 44033Korea Department of Pathology Ulsan University HospitalUniversity of Ulsan College of MedicineUlsan 44033Korea Department of Thoracic and Cardiovascular Surgery Ulsan University HospitalUniversity of Ulsan College of MedicineUlsan 44033Korea

To apply a new airway treatment to humans, preclinical studies in an appropriate animalmodel is needed. Canine, porcine and leporine tracheas have been employed as animal airwaystenosis models using various methods such as chemical caustic agents, laser, and ***, existing models take a long time to develop (3- 8 weeks) and the mechanism of stenosisis different from that in humans. The aim of the present study was to establish a new and fasttracheal stenosis model in pigs using a combination of cuff overpressure intubation (COI) andelectrocautery. Fourteen pigs were divided into three groups: tracheal cautery (TC) group (n=3),COI group (n=3), and COI-TC combination group (n=8). Cuff overpressure (200/400/500 mmHg)was applied using a 9-mm endotracheal tube. Tracheal cautery (40/60 watts) was performed usinga rigid bronchoscopic electrocoagulator. After intervention, the pigs were observed for 3 weeks andbronchoscopy was performed every 7 days. When the cross-sectional area decreased by > 50%, itwas confirmed that tracheal stenosis was established. The time for tracheal stenosis was 14 days inthe TC group and 7 days in the COI-TC combination group. In the COI group, no stenosis *** the COI-TC group, electrocautery (40 watts) immediately after intubation for>1 h with a cufpressure of 200 mmHg or more resulted in suficient tracheal stenosis within 7 days. moreover, thedegree of tracheal stenosis increased in proportion to the cuff pressure and tracheal intubation *** combined use of cuf overpressure and electrocautery helped to establish tracheal stenosis inpigs rapidly.

关键词： pig tracheal stenosis model cuff overpressure electrocautery

Construction of recombinant human nerve growth factor beta adenovirus and evaluation of its function An in vitro and in vivo study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2010年第16期5卷 1261-1269页

作者： En-Feng Gao Si-Ho Choi Mi-Ae Sung Bo-Han Li Samir Jabaiti Sang bae Yoo Sung-June Kim Soung-Min Kim jeong Won Jahng Jong-Ho Lee Department of Stomatology China-Japan Friendship Hospital Beijing 100029 China Center for Stem Cell and Regenerative Medicine Keck School of Medicine University of Sourthern Californina USA Department of Oral and Maxillofacial Surgery & Dental Research Institute Seoul National University Seoul Korea Department of Plastic and Reconstructive Surgery Jordan University Hospital Amman Jordan Department of Electrical Engineering School of Electrical and Computer Science Seoul National University Seoul Korea

Exogenous delivery of nerve growth factor （NGF） promotes neural regeneration. However, the short half-life limits delivery efficacy. Therefore, a long-term, efficient, local delivery tool or scheme is needed. The purpose of this study was to construct a functioning, recombinant, adenoviral vector carrying human NGF-β （hNGF-β） DNA, and to measure expression of the constructed vector in vitro and in vivo. rhNGF-β adenoviral vector containing full-length hNGF-β cDNA was generated by homologous recombination in Escherichia CoIL The rhNGF-β adenovirus was packaged and amplified in human embryonic kidney HEK293 cells. Transformation efficiency, expression and function of rhNGF-β adenovirus for primary Schwann cells, Schwann cell lines, human embryonic kidney HEK 293 cells, CRH myoblasts, and NIH3T3 fibroblasts were evaluated. Subsequently, expression of rhNGF-β adenovirus at the peripheral nerve of rat was also assessed. Recombinant adenoviral vector carrying hNGF-β was successfully constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. Green fluorescent protein expression was observed in 90% of rhNGF-β adenovirus-infected cells （primary Schwann cells, Schwann cell line, human embryonic kidney HEK 293 cells, CRH myoblasts, and NIH3T3 fibroblasts） compared with non-infected cells. Total mRNA isolated from rhNGF-β adenovirus-infected cells exhibited strong expression. Maximum NGF release was induced by primary cultured Schwann cells at 4 days after infection, which steadily continued for 14 days. PC-12 cells exposed to media conditioned with rhNGF-β adenovirus-infected Schwann cells exhibited increased neurite extension. In vivo experiment revealed that the injected rhNGF-β adenovirus was transfected into the cells at the injected site and promoted expression of NGF, p75NTR and brain derived neurotrophic factor at the sciatic nerve and dorsal root ganglia.

关键词： nerve growth factor Schwann cell peripheral nerve regeneration adenoviral vector HEK293 cells myoblasts fibroblasts

Gut microbiome composition can predict the response to nivolumab in advanced hepatocellular carcinoma patients

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2021年第42期27卷 7340-7349页

作者： Min-Woo Chung moon-Ju Kim Eun jeong Won Yu jeong Lee Yong-Woon Yun Sung Bum Cho Young-Eun Joo Jun-Eul Hwang Woo Kyun bae Ik-Joo Chung Myung Geun Shin Jong Hee Shin Department of Internal Medicine Chonnam National University Hospital and College of MedicineHwasun 58128Jeollanam-doSouth Korea Department of Parasitology and Tropical Medicine Chonnam National University Medical SchoolHwasun 58128Jeollanam-doSouth Korea Department of Laboratory Medicine Chonnam National University Hwasun HospitalHwasun 58128Jeollanam-doSouth Korea Department of Preventive Medicine Chonnam National University Medical SchoolHwasun-eupHwasun 58128Jeollanam-doSouth Korea Department of Laboratory Medicine Chonnam National University HospitalGwangju 61469South Korea

BACKGROUND Immunotherapy has revolutionized the clinical outcomes of intractable cancer *** is known about the intestinal nonpathogenic bacterial composition of hepatocellular carcinoma(HCC)patients treated by *** To determine whether there is a correlation between gut bacterial composition and prognosis in HCC *** From September 2019 to March 2020,we prospectively collected fecal samples and examined the gut microbiome of 8 advanced HCC patients treated with nivolumab as a second-or third-line systemic *** samples were collected before the start of *** samples of patients with progression during treatment were collected at the time of progression,and fecal samples of patients who showed good response to nivolumab were collected after 5-7 mo as *** data from 16S ribosomal RNA sequencing were analyzed using CLC Genomics *** data were analyzed according to therapeutic *** All 8 patients were male,of which 6 had underlying chronic hepatitis B.A higher Shannon index was found in the responders than in the non-responders after nivolumab therapy(P=0.036).The unweighted beta diversity analysis also showed that the overall bacterial community structure and phylogenetic diversity were clearly distinguished according to therapeutic *** was no significant difference in the diversity or composition of the patient gut microbiome according to the immunotherapy *** taxa specific to therapeutic response were designated as follows:Dialister pneumosintes,Escherichia coli,Lactobacillus reteri,Streptococcus mutans,Enterococcus faecium,Streptococcus gordonii,Veillonella atypica,Granulicatella sp.,and Trchuris trichiura for the nonresponders;Citrobacter freundii,Azospirillum *** Enterococcus durans for the *** note,a skewed Firmicutes/Bacteroidetes ratio and a low Prevotella/Bacteroides ratio can serve as predictive markers of non-response,wh

关键词： Microbiome Nivolumab Firmicutes/Bacteroidetes ratio Prevotella/Bacteroides ratio Hepatocellular carcinoma Prognosis

EP-Bot: Empathetic Chatbot Using Auto-Growing Knowledge Graph

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第6期67卷 2807-2817页

作者： SoYeop Yoo OkRan jeong Gachon University Seongnam-si13120Korea

People occasionally interact with each other through *** particular,we communicate through dialogue and exchange emotions and information from *** are essential characteristics of natural *** artificial intelligence is an integral part of all the technologies that allow computers to communicate like *** a computer to interact like a human being,it must understand the emotions inherent in the conversation and generate the appropriate ***,existing dialogue systems focus only on improving the quality of understanding natural language or generating natural language,excluding *** propose a chatbot based on emotion,which is an essential element in ***-Bot(an Empathetic PolarisX-based chatbot)is an empathetic chatbot that can better understand a person’s utterance by utilizing PolarisX,an autogrowing knowledge *** extracts new relationship information and expands the knowledge graph *** is helpful for computers to understand a person’s common *** proposed EP-Bot extracts knowledge graph embedding using PolarisX and detects emotion and dialog act from the *** it generates the next utterance using the ***-Bot could understand and create a conversation,including the person’s common sense,emotion,and *** verify the novelty and accuracy of EP-Bot through the experiments.

关键词： Emotional chatbot conversational AI knowledge graph emotion 1 Introduction

Virtual mold Technique in Thermal Stress Analysis during Casting Process

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第3期24卷 359-363页

作者： Si-Young Kwak Jae-Wook baek jeong-Ho Nam jeong-Kil Choi E-Design Center Korea Institute of Industrial Technology Department of Virtual Engineering Korea University of Science & Technology

It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

关键词： Casting process Thermal stress analysis Virtual mold

Comparison of litterfall production in three forest types in Jeju Island, South Korea

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2020年第3期31卷 945-952页

作者： Ji Young An Si Ho Han Woo Bin Youn Sang Ick Lee Afroja Rahman Huong Thi Thuy Dao jeong Min Seo Aung Aung Hyung-Soon Choi Hwa Ja Hyun Byung bae Park Department of Natural Resources Kyoto UniversityKyoto 606-8502Japan Department of Environment and Forest Resources Chungnam National UniversityDaejeon 34134Republic of Korea Forest Environment Conservation Division Korea Forest ServiceDaejeon 35208Republic of Korea Forest Conservation Department National Institute of Forest ScienceSeoul 02455Republic of Korea Warm Temperate and Subtropical Forest Research Center National Institute of Forest ScienceSeogwipo 63582Republic of Korea

Litterfall, which is influenced by physical and biological factors, is a major pathway for carbon and nutrient cycling in forest ecosystems. The purpose of this study was to investigate monthly litterfall production in three forests in Jeju Island differentiated by forest composition and precipitation: Cheongsu(Quercus glauca as the dominant species;low precipitation), Seonheulb(Q. glauca as the dominant species;high precipitation), and Seonheulm(Q. glauca and Pinus thunbergii as the dominant species;high precipitation). Litterfall was collected monthly from April to December 2015 and divided into leaf litter, twig, bark, seeds, and unidentified *** patterns of litterfall production varied across stands according to their species composition. However,the amount of leaf litterfall and total litterfall were comparable among stands, ranging from 362 to 375 g m-2 for leaf litter and 524 g m-2 to 580 g m-2 for total *** leaf litter in May was the highest in all stands, while needle litter was the highest in December in *** twig litterfall in July may be attributable to high rainfall with strong winds and storms during the rainy season. Although forest type and climate factor had no influence on litterfall amounts in this study, the pattern of litterfall production was species dependent, suggesting diverse effects on carbon and nutrient cycling in these forests.

关键词： Coniferous forest Evergreen broadleaved forest Gotjawal Leaf litter Precipitation Temperature