检索结果-南通市图书馆

Mechanical strength and corrosion resistance of Al-additive friction stir welded AZ31B joints

Journal of Magnesium and Alloys 2023年第5期11卷 1519-1535页

作者： Jae-yeon Kim Eun-Woo Kim Dong-O Kim Eun-Kyo Ju Ji-Eun lee Jaeheon lee Jai-won Byeon Mining Engineering Department Colorado School of MinesGoldenCO 80401USA Department of Materials Science and Engineering Seoul National University of Science and TechnologySeoul 01811Republic of Korea

Compared to other structural alloys,magnesium alloys have a relatively poor corrosion resistance and low mechanical strength,which can be further deteriorated when these alloys are subjected to joining processes using the existing joining ***,we propose for the first time an additive friction stir-welding(AFSW)using fine Al powder as an additive to improve the mechanical strength as well as corrosion resistance of AZ31B weld *** is a solid-state welding method of forming a high-Al AZ31B joint via an in-situ reaction between pure Al powders filled in a machined groove and the AZ31B *** optimize the process parameters,AFSW was performed under different rotational and transverse speeds,and number of passes,using tools with a square or screw *** particular,to fabricate a weld zone,where the Al was homogenously dispersed,the effects of the groove shape were investigated using three types of grooves:surface one-line groove,surface-symmetric grooves,and inserted symmetric *** homogenous and defect-less AFS-welded AZ31B joint was successfully fabricated with the following optimal parameters:1400 rpm,25 mm/min,four passes,inserted symmetric grooves,and the tool with a square *** AFSW fully dissolved the additive Al intoα-Mg and in-situ precipitated Mg_(17)Al_(12)particles,which was confirmed via scanning electron microscopy,transmission electron microscope,and X-ray diffraction *** microhardness,joint efficiency,and elongation at the fracture point of the AFS-welded AZ31B joint were 80 HV,101%,and 8.9%,*** values are higher than those obtained for the FS-welded AZ31 joint in previous *** corrosion resistance of the AFS-welded AZ31B joint,evaluated via hydrogen evolution measurements and potentiodynamic polarization tests,was enhanced to 55%relative to the FS-welded AZ31B joint.

关键词： AZ31B magnesium alloy Additive friction stir-welding In-situ reaction Mg_(17)Al_(12)particles Joint efficiency Corrosion resistance

来源：

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

Body-centered-cubic martensite and the role on room-temperature tensile properties in Si-added SiVCrMnFeCo high-entropy alloys

引用

Journal of Materials Science & Technology 2021年第17期76卷 222-230页

作者： Yong Hee Jo Junha Yang won-Mi Choi Kyung-yeon Doh Donghwa lee Hyoung Seop Kim Byeong-Joo lee Seok Su Sohn Sunghak lee Center for High Entropy Alloys Pohang University of Science and TechnologyPohang 37673South Korea Department of Materials Science and Engineering Division of Advanced Materials SciencePohang University of Science and TechnologyPohang 37673South Korea Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohang 37673South Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841South Korea

We present a new class of metastable high-entropy alloys(HEAs),triggering deformation-induced martensitic transformation(DIMT)from face-centered-cubic(FCC)to body-centered-cubic(BCC),i.e.,*** the ab-initio calculation based on 1 st order axial interaction model and combined with the Gibbs free energy calculation,the addition of Si is considered as a critical element which enables to reduce the intrinsic stacking fault energy(ISFE)in Si_xV_((9-x))Cr_(10)Mn_5 Fe_(46)Co_(30)(x=2,4,and 7 at.%)alloy *** ISFE decreases from-30.4 to-35.5 mJ/m^(2)as the Si content increases from 2 to 7 at.%,which well corresponds to the reduced phase stability of FCC against *** BCC-DIMT occurs in all the alloys via intermediate HCP martensite,and the HCP martensite provides nucleation sites of BCC ***,the transformation rate enhances as the Si content increases in an earlier deformation ra ***,the BCC-DIMT is also affected by the phase stability of FCC against BCC,and the stability is the highest at the Si content of 7 at.%.Thus,the 7Si alloy presents the moderate transformation rate in the later deformation *** to the well-controlled transformation rate and consequent strain-ha rdening rate,the 7Si alloy possesses the superior combination of strength and ductility beyond 1 GPa of tensile strength at room *** results suggest that the Si addition can be a favorable candidate in various metastable HEAs for the further property improvement.

关键词： High-entropy alloy(HEA) Deformation-induced martensitic transformation(DIMT) Phase stability Stacking fault energy(SFE)

来源：

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

Rapid re-emergence of YMDD mutation of hepatitis B virus with hepatic decompensation after lamivudine retreatment

引用

World Journal of Gastroenterology 2008年第27期14卷 4416-4419页

作者： So Young Kwon won Hyeok Choe Chang Hong lee Jong Eun yeon Kwan Soo Byun Department of Internal Medicine Konkuk University School of Medicine Department of Internal Medicine Korea University College of Medicine

Lamivudine has a high rate of antiviral resistance. Sequential treatment of anti-hepatitis B virus (HBV) is commonly used for lamivudine resistance. We report 4 cases of patients with rapid redetection of HBV mutants during the lamivudine retreatment. The four patients received lamivudine as an initial treatment of HBV and adefovir and lamivudine as a rescue therapy consecutively. HBV-DNA level, YMDD mutations and adefovir -resistant mutations (RFMP) were tested every 3 mo during the sequential treatment. All the patients showed YMDD mutations during the initial lamivudine therapy. After adefovir therapy for lamivudine resistance, they showed viral breakthrough. Adefovir was switched to lamivudine, however, it did not induce viral suppression at all, rather increased HBV-DNA with rapid reemergence of the YMDD mutations. All the patients had ALT flares, and hepatic decompensation occurred in two patients. After switching to adefovir combined with entecavir or lamivudine for a rescue therapy, the patients had reduction in HBV-DNA and ALT improvement. These cases demonstrated that lamivudine retreatment of patients with preexposed lamivudine resistance leads to rapid reemergence of YMDD mutation with significant viral rebounds and subsequent hepatic decompensation. Sequential administration of lamivudine in patients with a prior history of YMDD mutation should be abandoned.

关键词： Hepatitis B Lamivudine Adefovir dipivoxil Mutations

来源：

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

Direct optical-structure correlation in atomically thin dichalcogenides and heterostructures

引用

Nano Research 2020年第5期13卷 1363-1368页

作者： Akshay Singh Hae yeon lee Silvija Gradcak Department of Materials Science and Engineering Massachusetts Institute of Technology77 Massachusetts AveCambridgeMA 02141USA

Atomically thin transition metal dichalcogenides(TMDs)have distinct opto-electronic properties including enhanced luminescence and high on-off current ratios,which can be further modulated by making more complex TMD ***,resolution limits of conventional optical methods do not allow for direct nanoscale optical-structural correlation measurements in these materials,particularly of buried interfaces in TMD *** we use,for the first time,electron beam induced cathodoluminescence in a scanning transmission electron microscope(CL-STEM)to measure optical properties of monolayer TMDs(WS2,MoS2 and WSSe alloy)encapsulated between layers of *** observe dark areas resulting from localized(~100 nm)imperfect interfaces and monolayer folding,which shows that the intimate contact between layers in this application-relevant heterostructure is required for proper inter layer *** also realize a suitable imaging method that minimizes electron-beam induced changes and provides measurement of intrinsic *** overcome the limitation of small electron interaction volume in TMD monolayer(and hence low photon yield),we find that encapsulation of TMD monolayers with hBN and subsequent annealing is ***-STEM offers to be a powerful method to directly measure structure-optical correspondence in lateral or vertical heterostructures and alloys.

关键词： cathodoluminescence two-dimensional(2D)materials transition metal dichalcogenides interfaces heterostructures

来源：

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

Prediction of nephrotoxicity induced by cisplatin combination chemotherapy in gastric cancer patients

引用

World Journal of Gastroenterology 2011年第30期17卷 3510-3517页

作者： Hyung Hwan Moon Kyung won Seo Ki Young Yoon yeon Myung Shin Kyung Hyun Choi Sang Ho lee Department of Surgery Kosin University College of Medicine602-703 BusanSouth Korea

AIM:To evaluate the treatment options for nephrotoxicity due to cisplatin combination ***:We retrospectively reviewed patients who had received cisplatin combination chemotherapy for gastric cancer between January 2002 and December *** investigated patients who had shown acute renal failure(ARF),and examined their clinical characteristics,laboratory data,use of preventive measures,treatment cycles,the amount of cisplatin administered,recovery period,subsequent treatments,and renal status between the recovered and unrecovered ***:Forty-one of the 552 patients had serum creatinine(SCR)levels greater than 1.5 mg/*** found that pre-ARF SCR,ARF SCR,and ARF glomerular filtration rates were significantly associated with renal status postARF between the two groups(P=0.008,0.026,0.026,respectively).On the receiver operating characteristic curve of these values,a 1.75 mg/dL ARF SCR value had 87.5%sensitivity and 84.8%specificity(P=0.011).CONCLUSION:Cessation or reduction of chemotherapy should be considered for patients who have an elevation of SCR levels during cisplatin combination chemotherapy.

关键词： Acute renal failure Cisplatin Drug toxicities Nephrotoxicity

来源：

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

Hypothyroid effects on astrocytes and microglia in the adult rat hippocampus

引用

Neural Regeneration Research 2009年第12期4卷 1078-1082页

作者： Choong Hyun lee Jung Hoon Choi In Koo Hwang Ki-yeon Yoo Hyung-Cheul Shin Moo-Ho won Department of Anatomy and Neurobiology and Institute of Neurodegeneration and NeuroregenerationCollege of MedicineHallym University South Korea Institute of Naturat Medicine Hallym University Department ofAnatomy and Cell Biology College of Veterinary Medicine and BK21 Program for Veterinary ScienceSeoul National Unlversity South Korea Institute of Natural Medicine Hallym University Department of Physiology College of MedicineHallym University

BACKGROUND： Thyroid hormones modulate proliferation of astrocytes and microglia depending on maturation stage and localization. Studies have demonstrated that triiodothyronine treatment or thyroidectomy during developmental stages results in morphological alterations and changes in the number of astrocytes and microglia. Little is known about the effects of hypothyroidism on astrocytes and microglia in adults. OBJECTIVE： To investigate the effects of hypothyroidism on morphology and number of astrocytes and microglia in the adult rat hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, neuroendocrinological, animal study was performed at the College of Medicine, Hallym University, South Korea between May 2008 and April 2009. MATERIALS： Methimazole, rabbit anti-glial fibrillary acidic protein （GFAP） antiserum, and rabbit anti-lba-1 antiserum were purchased from Sigma, USA. Rabbit anti-GFAP polyclonal antibody was provided by Chemicon, USA. Rabbit anti-lba-1 polyclonal antibody was purchased from Wako, Japan. Terminal deoxynucleotidyl transferase dUTP-biotin nick-end-labeling （TUNEL） kit was provided by Roche Molecular Biochemicals, Mannheim, Germany. METHODS： Hypothyroidism was induced in Wistar rats via methimazole administration （0.025%） in drinking water for 5 weeks, starting at 6 months of age. MAIN OUTCOME MEASURES： Following methimazole treatment, hippocampai neuronal death was determined using TUNEL staining. The morphology and number of GFAP and lba-1 immunoreactive cells were detected by immunohistochemistry. Hippocampal GFAP and lba-1 protein levels were detected by Western blot analysis. Serum-free triiodothyronine and thyroxine levels were quantified. RESULTS： TUNEL-positive neurons were not observed in the hippocampus of euthyroid and hypothyroid rats. Compared with the euthyroid rats, the number of GFAP immunoreactive astrocytes was decreased, and serum triiodothyronine and thyroxine levels were significantly decreased. In contrast, the numb

关键词： astrocytes hippocampus hypothyroidism microglia Wistar rats

来源：

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

Polyherbal formula SC-E3 inhibits rheumatoid arthritis activity in a mouse model of type-Ⅱcollagen-induced arthritis

引用

Journal of Integrative Medicine 2021年第3期19卷 265-273页

作者： Ju-yeon Park Young-won Kwon Sun-Ah Kim Sun-Dong Park Chang-Hyun Kim Jin-Hee Kim Ju-Hee lee College of Korean Medicine Dongguk UniversityGoyang 10326Republic of Korea Department of Medicine College of MedicineDongguk UniversityGoyang 10326Republic of Korea Department of Biomedical Laboratory Science College of Health ScienceCheongju UniversityCheongju 28503Republic of Korea

Objective:SC-E3 is a polyherbal formula that contains five medicinal herbs used frequently in traditional herbal *** our previous study,we demonstrated the antioxidant and anti-inflammatory effects of *** present study examined the effects of SC-E3 in a mouse model of type-II collagen-induced arthritis(CIA).Methods:In vivo,male DBA/1 J mice were immunized by intradermal injection of bovine type-II collagen and complete or incomplete Freund’s adjuvant,to induce ***-E3 was orally administered daily for 23 *** vitro,bone marrow-derived macrophages(BMMs)were treated with macrophage colony-stimulating factor(M-CSF)and receptor activator of nuclear factor-j B ligand(RANKL)in the absence or presence of ***:Administrations of SC-E3 were found to have anti-arthritic effects in the joints of CIA mice,as evidenced by reduced paw swelling,bone erosion and deformation,inflammatory cell infiltration,and inflammation in synovial ***-E3 also reduced serum levels of tumor necrosis factor-a,interleukin-1 b,aspartate aminotransferase and alanine ***,tartrateresistant acid phosphatase-positive osteoclast numbers in the joints were significantly lower in SC-E3-treated CIA mice than in CIA *** addition,the differentiations of BMMs to multinucleated osteoclasts induced by M-CSF and RANKL stimulation were dose-dependently reduced by ***:These results suggest that SC-E3 possesses substantial anti-arthritic activity because it inhibits pro-inflammatory cytokines and osteoclastogenesis,and that SC-E3 has potential therapeutic use for the treatment of rheumatoid arthritis.

关键词： Herbal formula Anti-inflammatory Rheumatoid arthritis Collagen-induced arthritis Osteoclastogenesis

来源：

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

Significant control of metal-insulator transition temperature through catalytic excessive oxygen doping in high-performance vanadium dioxide nanobeam channel

引用

Journal of Materials Science & Technology 2020年第9期44卷 96-101页

作者： Minhwan Ko Sang yeon lee Jucheol Park Hyungtak Seo Department of Energy Systems Research Ajou UniversitySuwon16499Republic of Korea Gyeongbuk Science Technology Promotion Center Gumi Electronics&Information Technology Research InstituteGumi39717Republic of Korea Department of Materials Science and Engineering Ajou UniversitySuwon16499Republic of Korea

The strategy of a reliable transition temperature control of vanadium dioxide(VO2)is *** VO2 nanobeams were synthesized by a thermal chemical vapor deposition(TCVD)*** metal-insulator transition(MIT)temperature increases to above 380K when the TiO2 ratio of the source is 5 at.%,although the Ti source is not physically doped into VO2 *** XPS spectra of the V 2p orbital reveal the excessive oxidation of V after the TCVD processes with a higher TiO2 ratio,indicating that the TiO2 precursor is important in the O-doping of the surface V O bonds when forming volatile Ti-O gas ***,TiO2 reactants can be used as a VO2 surface chemical modifier to manipulate the MIT transition temperature and maintain a homogenous VO2 phase,which is useful for a Mott device application with a record on/off switching ratio>104 and Mott transition temperature>380 K.

关键词： VO2 Mott transition Metal-insulator transition temperature Oxygen doping Titanium catalyst

来源：

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

Iodized oil uptake assessment with cone-beam CT in chemoembolization of small hepatocellular carcinomas

引用

World Journal of Gastroenterology 2009年第46期15卷 5833-5837页

作者： Ung Bae Jeon Jun Woo lee Ki Seok Choo Chang won Kim Suk Kim Tae Hong lee yeon Joo Jeong Dae Hwan Kang Department of Radiology Pusan National University Yangsan Hospital Department of Radiology Pusan National University Hospital Department of Internal Medicine Pusan National University Yangsan Hospital

AIM:To evaluate the utility of assessing iodized oil uptake with cone-beam computed tomography(CT)in transarterial chemoembolization(TACE)for small he-patocellular carcinoma(HCC).METHODS:Cone-beam CT provided by a biplane flat-panel detector angiography suite was performed on eighteen patients(sixteen men and two women;41-76 years;mean age,58.9 years)directly after TACE for small HCC(26 nodules under 30 mm;mean diam-eter,11.9 mm;range,5-28 mm).The pre-procedural locations of the tumors were evaluated using tripha-sic multi-detector row helical computed tomography(MDCT).The tumor locations on MDCT and the iodized oil uptake by the tumors were analyzed on cone-beam CT and on spot image directly after the ***:All lesions on preprocedural MDCT were de-tected using iodized oil uptake in the lesions on cone-beam CT(sensitivity 100%,26/26).Spot image depictediodized oil uptake in 22 of the lesions(sensitivity 85%).The degree of iodized oil uptake was overestimated(9%,2/22)or underestimated(14%,3/22)on spot image in f ive nodules compared with that of cone-beam ***:Cone-beam CT is a useful and conve-nient tool for assessing the iodized oil uptake of small hepatic tumors(< 3 cm)directly after TACE.

关键词： Chemoembolization Computed tomography Hepatocellular carcinoma Liver

来源：

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

Comparison of the rheological properties of four root canal sealers

引用

International Journal of Oral Science 2015年第1期7卷 56-61页

作者： Seok Woo Chang Young-Kyu lee Qiang Zhu won Jun Shon Woo Cheol lee Kee yeon Kum Seung Ho Baek In Bog lee Bum-Soon Lim Kwang Shik Bae Department of Conservative Dentistry School of Dentistry Kyung Hee University National Instrumentation Center for Environmental Management Seoul National University Department of Endodontology School of Dental Medicine University of Connecticut Health Center Department of Conservative Dentistry Dental Research Institute School of Dentistry Seoul National University Dental Hospital Seoul National University Dental Research Institute and Department of Dental Biomaterials School of Dentistry Seoul National University

The flowability of a root canal sealer is clinically important because it improves the penetration of the sealer into the complex root canal system. The purpose of this study was to compare the flowabilities of four root canal sealers, measured using the simple press method （ISO 6876）, and their viscosities, measured using a strain-controlled rheometer. A newly developed, calcium phosphate-based root canal sealer （Capseal） and three commercial root canal sealers （AH Plus, Sealapex and Pulp Canal Sealer EWT） were used in this study. The flowabilities of the four root canal sealers were measured using the simple press method （n= 5） and their viscosities were measured using a strain-controlled rheometer （n=5）. The correlation between these two values was statistically analysed using Spearman＇s correlation test. The flow diameters and the viscosities of the root canal sealers were strongly negatively correlated （p= -0.8618）. The viscosity of Pulp Canal Sealer EWT was the lowest and increased in the following order： AH Plus〈Sealapex〈Capseal （P〈0.05）. All of the tested root canal sealers showed characteristic time- and temperature-dependent changes in their rheological properties. The viscosities measured using the strain-controlled rheometer were more precise than the flowabilities measured using the simple press method, suggesting that the rheometer can accurately measure the rheological properties of root canal sealers.

关键词： Capseal rheological property root canal sealer strain-controlled rheometer

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：