检索结果-南通市图书馆

Effects of PWHT on Microstructure and Mechanical Properties of Weld Metals of Ni-Based Superalloy 617 and 263 for Hyper-Supercritical Power Plants

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2016年第12期29卷 1107-1118页

作者： Jeong Kil kim Hae Ji Park Deog nam Shim Doosan Heavy Industries and Construction ChangwonGeongnam Korea

It is well known that solid solution-strengthened alloy 617 and γ′ precipitation-strengthened alloy 263 have excellent mechanical properties and corrosion resistance at high temperatures. Hyper-supercritical power plants work at temperatures above 700 ℃, and these superalloys are considered candidate materials for steam turbines components of these power plants. In this study, gas tungsten arc weldability of these superalloys was evaluated, and the effects of post- weld heat treatment （PWHT） on the microstructural characteristics and the mechanical properties of their weld metals were investigated. Scanning transmission electron microscopy, energy-dispersive spectroscopy and electron probe microanalysis were utilized for the investigation. The experimental results confirmed that these weld metals had different characteristics in microstructure and mechanical properties. PWHT resulted in the precipitation of intergranular carbides, γ′ particles and an increase in tensile strength of these superalloy weld metals. Furthermore, fine γ′ particles, which were not detected in the as-welded metal of alloy 263, were precipitated after PWHT and those particles were the reason for the drastic increase in tensile strength.

关键词： Superalloy Welding Precipitation Segregation

Aging Behavior of Mg-Y-Zr and Mg-Nd-Zr Cast Alloys

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第1期24卷 80-84页

作者： Yang-Do kim nam-Hyun Kang Il-Guk Jo Kyung-Hyun kim In-Bae kim School of Materials Science and Engineering Pusan National University 30 Jangjun-dongGeumjeong-guBusan 609-735Korea Deptartment of Materials Engineering Korea Institute of Machinery & Materials 66 Sangnam-dongChangwonGyeongsangnam-do 641-010Korea

Aging behavior of Mg-3.6Y-0.5Zr and ***-0.5Zr alloys was investigated by microhardness measurement and transmission electron *** the case of Mg-Y-Zr alloy,the presence ofβ″phase,a major strength- ener,having base centered orthorhombic structure with its lattice constants of a-（β″）=0.64 nm,b-（β″）=2.22 nm, and c-（β″）=0.52 nm was *** the case of Mg-Nd-Zr alloy aged at 250℃,the presence ofβ″andβ′phases was *** crystal structure ofβ″phase was found to be DO-（19） and its orientation relationships with Mg matrix were [0001]-（β″）//[0001]-（Mg） and [01（？）0]-（β″）//[01（？）0]-（Mg）.Theβ′phase had face centered cubic structure and its orientation relationships with Mg matrix were [011]-（β′）//[0001]-（Mg） and [（？）1（？）]β′//[（？）110]）-（Mg）. The ***-0.5Zr alloy showed higher hardness compared with Mg-3.6Y-0.5Zr alloy.

关键词： Mg-Y-Zr alloy Mg-Nd-Zr alloy Precipitation sequence

A Review of David Gottlieb’s Work on the Resolution of the Gibbs Phenomenon

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2011年第3期9卷 497-519页

作者： Sigal Gottlieb Jae-hun Jung Saeja kim Mathematics Department University of Massachusetts DartmouthNorth DartmouthMA 02747USA Mathematics Department Suny BuffaloBuffaloNew York 14260-2900USA

Given a piecewise smooth function,it is possible to construct a global expansion in some complete orthogonal basis,such as the Fourier ***,the local discontinuities of the function will destroy the convergence of global approximations,even in regions for which the underlying function is *** global expansions are contaminated by the presence of a local discontinuity,and the result is that the partial sums are oscillatory and feature non-uniform *** characteristic behavior is called the Gibbs ***,David Gottlieb and Chi-Wang Shu showed that these slowly and non-uniformly convergent global approximations retain within them high order information which can be recovered with suitable *** this paper we review the history of the Gibbs phenomenon and the story of its resolution.

关键词： Gibbs phenomenon post-processing Galerkin approximation collocation approximation spectral methods exponential accuracy

A case of colohepatic penetration by a swallowed toothbrush

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第15期12卷 2464-2465页

作者： Min Ro Lee Yong Hwang Jong hun kim Department of Surgery Chonbuk National University Medical School San 2-20 Geumam-dongDeokjin-guJeonjuJeonbuk 561-180South Korea Research Institute of Clinical MedicineChonbuk National University Medical SchoolSan 2-20 Geumam-dongDeokjin-guJeonjuJeonbuk 561-180South Korea Department of Surgery Chonbuk National University Medical School San 2-20 Geumam-dongDeokjin-guJeonjuJeonbuk 561-180South Korea

Although foreign body ingestion is relatively common,toothbrush swallowing is rare. We report a case of a swallowed toothbrush which passed through the ileocecal valve and perforated the proximal transverse colon,then... 详细信息

关键词： Toothbrush Colohepatic penetration

A left-sided periappendiceal abscess in an adult with intestinal malrotation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第33期12卷 5399-5400页

作者： Min Ro Lee Jong hun kim Yong Hwang Young Kon kim Department of Surgery Chonbuk National University Medical School San 2-20Geumam-dong Deokjin-gu Jeonju 561-756 South Korea Research Institute of ClinicalMedicine Chonbuk National University Medical School San2-20 Geumam-dong Deokjin-gu Jeonju 561-756 South Korea Department of Surgery Chonbuk National University Medical School San 2-20Geumam-dong Deokjin-gu Jeonju 561-756 South Korea Department of Diagnostic Radiology ChonbukNational University Medical School San 2-20 Geumam-dongDeokjin-gu Jeonju 561-756 South Korea

Left-sided periappendiceal abscesses occur in association with two types of congenital anomaly: intestinal malrotation and situs inversus. It is diffi cult to obtain an accurate preoperative diagnosis of these abscesses due to the abnormal position of the appendix. We present an unusual case of a left-sided periappendiceal abscess in an adult with intestinal malrotation, the diagnosis of which was a challenge.

关键词： Left-sided periappendiceal abscess intestinalmalrotation Diagnosis

Relief of YAP-mediated inhibition by IKKε promotes innate antiviral immunity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2018年第6期15卷 642-644页

作者： Nayoung kim Yun-Yong Park Chul Hyun Joo hun Sik kim Department of Convergence Medicine Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea Asan Institute for Life Sciences Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea Department of Microbiology Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea Department of Biomedical Sciences Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea

The innate immune response to invading viruses is critical for the mounting of protective immunity,in which type I interferons(IFN),for example,IFN-αandβ,are potent effector molecules.1 Most cell types,particularly fibroblasts and epithelial cells,produce IFN-β,whereas hematopoietic cells,notably plasmacytoid dendritic cells,are the predominant sources of IFN-α.IFNs potently stimulate a variety of innate and adaptive immune cells,including macrophages,NK cells and T *** binding of type I IFN to its cognate receptor triggers the activation of the Janus kinase signal transducer and activator of transcription pathway,which results in the transcription of IFNstimulated genes that play key roles in host resistance to viral infections.

关键词： immunity protective mount

Leptin and peroxisome proliferator-activated receptor γ expression in colorectal adenoma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2012年第6期18卷 557-562页

作者： Hyung hun kim You Sun kim Yun Kyung Kang Jeong Seop Moon Department of Internal Medicine Seoul Paik HospitalInje University College of MedicineSeoul 100-032South Korea Department of Pathology Seoul Paik HospitalInje University College of MedicineSeoul 100-032South Korea Hyung Hun Kim Department of Internal Medicine Kosin University College of MedicineBusan 602-702South Korea

AIM： To investigate the expressions of leptin and per- oxisome proliferator-activated receptor y （PPARG） in relation to body mass index （BMI）. METHODS： We evaluated leptin and PPARG expres- sion in 30 adenomas over 1 cm in size by immunohisto- chemical staining. In addition, clinicopathologic features including BMI were assessed. RESULTS： PPARG and leptin expression showed a strong positive correlation （P = 0.035）. The average BMI of the leptin-positive group was higher than that of the leptin-negative group （25.4 ＋ 3.4 kg/m2 vs 22.6 ＋ 2.4 kg/m2, P = 0.018）, and leptin expression was sig- nificantly correlated with high BMI （P = 0.024）. Leptinexpression was more frequently observed in intermedi- ate/high grade dysplasia than in low grade dysplasia （P = 0.030）. However, PPARG expression was not cor- related with BMI and grade of dysplasia. CONCLUSION： BMI has influenced on the leptin ex- pression of colorectal adenoma. The exact mechanism underlies the strong correlation between leptin and PPARG expression needs further study.

关键词： Leptin Peroxisome proliferator-activated re-ceptor y Obesity Body mass index Colorectal adenoma

Analyzing the distinguishing factors that affect childhood obesity in South Korea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Medicine 2018年第6期12卷 707-716页

作者： So Jung Yang hun-Sung kim Kun-Ho Yoon Department of Medical Informatics College of MedicineThe Catholic University of KoreaSeoul 06591Republic of Korea Division of Endocrinology and Metabolism Department of lnternal MedicineSeoul St.Mary's HospitalCollege of MedicineThe Catholic University of KoreaSeoul 06591Republic of Korea

Understanding obesity in children is crucial because it can lead to adulthood obesity and result in fatal chronic diseases. Distinctive factors associated with obesity in adults have been described, but distinctive factors related to children remain unclear. We analyzed the correlation between the percentage of body mass index and lifestyle habits by conducting surveys on physical, nutritional, and psychological factors, and we used annual physical examination data to compare different traits among elementary school students (n = 197) and middle school students (n = 461). Our study revealed that the computing hours in elementary school students with overweight and obesity were significantly correlated with the percentage of body mass index (r = 0.29 on school days and r = 0.35 on days off, all P0.05) in the computing hours of middle school students with overweight and obesity. Childhood obesity can cause depression and reduce children’s quality of life because of their distorted body perception. In conclusion, physical factors directly affecting childhood obesity and psychological and environmental factors surrounding a child should be considered.

关键词： screen time quality of life eating habits childhood obesity percentage of body mass index

Toward Systems Understanding of Leaf Senescence： An Integrated Multi-Omics Perspective on Leaf Senescence Research

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2016年第6期9卷 813-825页

作者： Jeongsik kim Hye Ryun Woo Hong Gil nam Center for Plant Aging Research Institute for Basic Science (IBS) Daegu 42988 Republic of Korea Department of New Biology DGIST Daegu 42988 Republic of Korea

Leaf senescence is a complex but tightly regulated developmental process involving a coordinated sequence of multiple molecular events, which ultimately leads to death of the leaf. Efforts to understand the mechanistic principles underlying leaf senescence have been largely made by transcriptomic, proteomic, and metabolomic studies over the past decade. This review focuses on recent milestones in leaf senes- cence research obtained using multi-omics technologies, as well as future endeavors toward systems understanding of leaf senescence processes. In particular, we discuss recent advances in understanding molecular events during leaf senescence through genome-wide transcriptome analyses in Arabidopsis. We also describe comparative transcriptome analyses used to unveil the commonality and diversity of regulatory mechanisms governing leaf senescence in the plant kingdom. Finally, we provide current illustrations of epigenomic, proteomic, and metabolomic landscapes of leaf senescence. We envisage that integration of multi-omics leaf senescence data will enable us to address unresolved questions regarding leaf senescence, including determining the molecular principles that coordinate concurrent and ordered changes in biological events during leaf senescence.

关键词： leaf senescence transcriptomics epigenomics proteomics metabolomics multi-omics