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Effects of Applied Stresses on Martensite Transformation in AISI4340 Steel

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Journal of Iron and Steel Research International 2007年第6期14卷 63-67页

作者： ZHAO Hong zhuang seok-jae lee Young-kook lee LIU Xiang-hua WANG Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Department of Metallurgical Engineering Yonsei University Seoul 120-749 South Korea

This study aims at the experimental analysis of the transformation induced plasticity （TRIP） phenomenon. Experiments are conducted in which martensite is allowed to grow under the influence of a series of externally applied stresses. The magnitude of the applied stresses is less than 67% of the yield strength of austenite σγ （Ts）. Since there is no obvious difference between the transformation plasticity under tension and the compression for the lower applied stresses, only compressive stresses are applied. The results confirm that the transformation plasticity is proportional to the applied stress if the latter does not exceed 67 % of σγ （Ts）. The TRiP-strain, the kinetics, and their dependence on the applied stresses are studied. The comparison between calculated results and experimental results shows that the model accurately describes the phenomenon.

关键词： applied stress TRIP martensite transformation low-alloy steel

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低碳薄板钢硬化时的氢脆

现代冶金（内蒙古） 2013年第3期 32-38页

作者： seok-jae lee[美国]

对10822（22MnB5）薄钢板拉伸试样进行奥氏体化后淬火成马氏体，在150～520℃温度之间进行不同时间回火，热处理试样充人1．7ppm氢后立即进行试验，用场散射扫描电镜检测表面裂纹，预淬成马氏体的试样表现出最严重的氢脆化，在低应力下... 详细信息

对10822（22MnB5）薄钢板拉伸试样进行奥氏体化后淬火成马氏体，在150～520℃温度之间进行不同时间回火，热处理试样充人1．7ppm氢后立即进行试验，用场散射扫描电镜检测表面裂纹，预淬成马氏体的试样表现出最严重的氢脆化，在低应力下产生了。在150～350℃之间回火试样出现了氢诱导断裂，其原因为滑移面结合力降低，粗大夹杂成为储氢场所。460℃和520℃回火试样显示出对氢脆敏感性较小，随回火温度提高后位错减少，渗碳体粒子吸收氢的能力减弱，氢致裂纹的敏感性逐步降低。在预淬火试样中，晶间裂纹非常少，因此认为B元素对硬化低碳钢的氢脆几乎没有影响。

关键词：氢脆回火马氏体低碳薄板钢机械性能 SEM分析断裂机理

考虑到合金元素影响的奥氏体中碳扩散的经验模型

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现代冶金（内蒙古） 2016年第2期 48-56页

作者： seok-jae lee 乔林锁周旨峰

碳在奥氏体中的扩散特性对设计和改善许多钢热处理工艺是非常重要的，本研究对铁碳食金及用不同元素合金化的钢奥氏体中碳扩散提出一个简单而有效的计算公式，提出的经验模型提供了为达到这个重要扩散工艺的工程程序，这个模型与文献所... 详细信息

碳在奥氏体中的扩散特性对设计和改善许多钢热处理工艺是非常重要的，本研究对铁碳食金及用不同元素合金化的钢奥氏体中碳扩散提出一个简单而有效的计算公式，提出的经验模型提供了为达到这个重要扩散工艺的工程程序，这个模型与文献所报道的其它公式相比显示出与一些渗碳合金钢碳扩散曲线有很好的吻合，其它这些公式主要从铁碳合金试验获得，但当与考虑到全范围合金成分的已报道公式相比，其缺少精确性是不足为奇的。

关键词：碳扩散合金对奥氏体中碳扩散的影响经验模型试验数据钢

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： Md Ahasan Habib Shusen Lin Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar jae-Hun Jeong Jihoon lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Advanced electrocatalyst High current Corrosion resistance Industrial requirement

Regulation of sleep by astrocytes in the hypothalamic ventrolateral preoptic nucleus

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Neural Regeneration Research 2025年第4期20卷 1098-1100页

作者： jae-Hong Kim Ruqayya Afridi Il-Sung Jang Maan Gee lee Kyoungho Suk Brain Korea 21 four KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of DentistryKyungpook National UniversityDaeguRepublic of Korea Brain Science&Engineering Institute Kyungpook National UniversityDaeguRepublic of Korea

Astrocytes are functionally dynamic cells that support neurons in multiple ways throughout an organism’s *** astrocytic regulation of neuronal activity has been increasingly recognized in recent *** are now recognized as playing a more complex role than mere bystanders in the central nervous ***,their role in regulating the sleep neurocircuitry is not well *** this perspective,we highlight the role of astrocytes in sleep modulation,with a particular focus on regulatory mechanisms related to the ventrolateral preoptic nucleus(VLPO)of the *** briefly discuss recent literature reporting the role of VLPO astrocytes in regulating sleep-associated behaviors.

关键词： sleep ventrolateral astrocytes

Pyunkang-hwan (Pyunkang-Tang) ameliorates air pollutant-induced inflammatory hypersecretion of airway mucus and bleomycin-induced pulmonary fibrosis in rats

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Journal of Traditional Chinese Medicine 2016年第5期36卷 663-670页

作者： Hyo-seok Seo Hyun jae lee Choong jae lee Department of Pharmacology School of Medicine Chungnam National University Department of Health Management Sahmyook University

OBJECTIVE: To investigate the effect of Pyunkanghwan(Pyunkang-tang) extract(PGT) on secretion of airway mucin in an experimental animal model involving hyperplasia of goblet cells and mucus hypersecretion, and to test its effects on bleomycin(BLM)-induced pulmonary fibrosis in ***: The protective activity of orally administered PGT was assessed in two rat pulmonary disease models. Effects on hypersecretion of pulmonary mucin in sulfur dioxide(SO_2)-induced bronchitis in rats were assessed by quantifying the amount of mucus secreted and examining histopathology in the tracheal epithelium. In a rat model for BLMinduced pulmonary fibrosis, toxicity to the pulmonary system was examined by measuring levels of malondialdehyde and hydroxyproline,indicators of lipid peroxides and collagen,respectively, in lung tissue 28 days post-BLM treatment. Serial sections of lung tissue were stained with Masson trichrome to visualize collagen deposition. Effects of PGT on collagen synthesis were also assessed in vitro, in a cell culture ***: PGT inhibited mucin secretion and normalized SO_2-induced increased muco- substances in goblet cells. In the BLM- induced model,PGT decreased the characteristic histopathological features of lung fibrosis and inhibited fibrotic lesions, as indicated by decreased hydroxyproline content. PGT also inhibited the BLM-induced increase in malondialdehyde levels, demonstrating its protective effect against lipid peroxidation in cell membranes of the lung. In MLg 2908 mouse lung fibroblast cells, PGT decreased transforming growth factor(TGF)-β-stimulated type I collagen ***: PGT can inhibit both hypersecretion of airway mucins and pulmonary fibrosis.

关键词： Pyunkang-hwan(Pyunkang-tang) Air pollutants Bleomycin Pulmonary fibrosis Airway mucin

Prediction of grain structure in direct-chill cast Al–Zn–Mg–Cu billets using cellular automaton-finite element method

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Progress in Natural Science:Materials International 2021年第3期31卷 434-441页

作者： Min-seok Kim Sang-Hwa lee jae-Gil Jung Kwangjun Eah Department of Materials Science and Engineering Gachon University Metallic Materials Division Korea Institute of Materials Science Department of Materials Science and Engineering Yonsei University

A cellular automaton-finite element(CA-FE) model was used to predict the solidification grain structure of permanent mold cast A7086 alloy. In this model, a Gaussian distribution of nucleation sites was adopted, and the Kurz-Giovanola-Trivedi model was extended to a multicomponent Al–Zn–Mg–Cu alloy system to determine the growth kinetics of the dendrite tip. For describing the Gaussian distribution of nucleation sites on the mold surface, an empirical relationship between the initial cooling rate of the melt and the nucleation density was proposed. Under various casting conditions, the calculated grain structures agreed well with the experimental results. Subsequently, the model was applied to the direct-chill(DC) cast billets, and the simulated grain structures reproduced well the experimental results. This confirmed that the current CA-FE model can be used practically and effectively in DC casting processes.

关键词： Cellular automaton-finite element (CA-FE) model Direct-chill casting Al–Zn–Mg–Cu alloy A7068 alloy Grain structure

Tamsulosin-induced life-threatening hypotension in a patient with spinal cord injury:A case report

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World Journal of Clinical Cases 2022年第25期10卷 9142-9147页

作者： jae Young lee Ho seok lee Si-Bog Park Kyu Hoon lee Rehabilitation Medicine Hanyang University HospitalSeoul 04763South Korea

BACKGROUND Tamsulosin,a selectiveα1-adrenergic receptor antagonist,is commonly used for treating neurogenic bladder in patients with spinal cord injury(SCI).No severe adverse events have been described with such tamsulosin *** our knowledge,we report the first case of severe life-threatening hypotension as an adverse effect of tamsulosin in a person with ***,we report this case to inform that this severe adverse effect of tamsulosin can occur when treating patients with *** SUMMARY A 59-year-old woman was diagnosed with cervical spinal cord myelopathy and was classified as American Spinal Injury Association Impairment Scale D,neurological level of injury *** she suffered from voiding difficulty due to neurogenic bladder,we prescribed *** vital signs remained stable,but occasional hypotensive symptoms followed *** reduced the dose of tamsulosin,but after administering tamsulosin for 9 d,she experienced lifethreatening hypotension with no evidence of hypovolemic shock,neurogenic shock,cardiogenic shock,or septic shock.A hypotensive condition induced by tamsulosin was the suspected cause,and her symptoms could be associated with adverse effects of *** symptoms resolved after stopping tamsulosin,and no other reason was found,we concluded that tamsulosin was the cause of her *** Caution for severe hypotension is needed when administering tamsulosin for neurogenic bladder in a patient with SCI.

关键词： Tamsulosin Neurogenic bladder Spinal cord injury Hypotension Vasovagal symptoms Case report

Spectrum of final pathological diagnosis of gastric adenoma after endoscopic resection

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World Journal of Gastroenterology 2011年第47期17卷 5177-5183页

作者： Kwan Woo Nam Kyu Sang Song Heon Young lee Byung seok lee jae Kyu Seong seok Hyun Kim Hee seok Moon Eaum seok lee Hyun Yong Jeong Gastroenterology Center Sun Hospital Pathologic Department Chung-Nam National University Hospital Gastroenterology Unit of Internal Medicine Department Chung-Nam National University Hospital

AIM: To investigate how many discrepancies occur in patients before and after endoscopic treatment of referred adenoma and the reason for these results. METHODS: We retrospectively reviewed data from 554 cases of 534 patients who were referred from primary care centres for adenoma treatment and treated for endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) at Chungnam National University Hospital, from July 2006 to June 2009. Reendoscopy was examined in 142 cases and biopsywas performed in 108 cases prior to treatment. Three endoscopists (1, 2 and 3) performed all EMRs or ESDs and three pathologists (1, 2 and 3) diagnosed most of the cases. Transfer notes, medical records and endoscopic pictures of these cases were retrospectively reviewed and analyzed. RESULTS: Adenocarcinoma was 72 (13.0%) cases in total 554 cases after endoscopic treatment of referred adenoma. When the grade of dysplasia was high (55.0%), biopsy number was more than three (22.7%), size was no smaller than 2.0 cm (23.2%), morphologic type was depressed (35.8%) or yamada type Ⅳ (100%), and color was red (30.9%) or mixed-or-undetermined (25.0%), it had much more malignancy rate than the others (P < 0.05). All 18 cases diagnosed as adenocarcinoma in the re-endoscopic forceps biopsy were performed by endoscopist 1. There were different malignancy rates according to the pathologist (P = 0.027). CONCLUSION: High grade dysplasia is the most important factor for predicting malignancy as a final pathologic diagnosis before treating the referred gastric adenoma. This discrepancy can occur mainly through inappropriately selecting a biopsy site where cancer cells do not exist, but it also depends on the pathologist to some extent.

关键词： Discrepancy Adenoma High grade dyspla-sia Endoscopic mucosal resection Endoscopic submu-cosal dissection