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Oxidation behavior of Ni-based superalloy GH4738 under tensile stress

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Rare Metals 2024年第8期43卷 3913-3920页

作者： Ji-Chong Hu Hai-Liang Huang Chong-Chong Wu Xiao-Yu Sun Jie Wang Yan-Hong Yang Jing-long qu Liang Jiang Jin-He Dou Yang Chen Institute for Advanced Studies in Precision Materials Yantai UniversityYantai 264005China Department of Management and Engineering Linkoping University58183LinkopingSweden Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Gaona Aero Material Co. LtdBeijing 100081China College of Artificial Intelligence and Big Data Shandong First Medical University and Shandong Academy of Medical SciencesJinan250117China

Revealing the oxidation behavior of superalloys is crucial for optimizing material properties and extending service *** study investigated the oxidation behavior of superalloy GH4738 under stress states at 850℃.High-throughput specimens were fabricated to withstand different stresses at the same *** oxidation s amples were analyzed using the mass gain method to obtain oxidation kinetic *** results show that the external stress below 200 MPa could improve the oxidation resistance of the *** tensile stress increasing,the oxide layer becomes thinner,denser and more complete,while internal oxidation *** tensile stress alters the structure of the external oxide layer from a two-layer to a threelayer *** Cr_(2)O_(3) oxide layer inhibits the outward diffusion of Ti,leading to Ti enrichment at the oxide-matrix interface and altering the oxidation mechanism of GH4738.

关键词： Ni-based Superalloy Oxidation behavior Tensile stress Oxide layer

Antiosteoporosis and bone protective effect of alpinumisoflavone in steroid-induced osteoporosis rats via alteration of apoptosis,inflammatory and RANK/RANKL/OPG signaling pathway

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Asian Pacific Journal of Tropical Biomedicine 2024年第10期14卷 436-447页

作者： Jie Lian Jun-long qu Guo-Wei Zhao Xu-Biao Ji Department of Orthopaedics Luzhou Traditional Chinese Medicine HospitalLuzhouSichuan646000China Department of Orthopedic Rehabilitation Shengli Oilfield Central HospitalDongyingShandong257000China Department of Spinal Surgery Changzhou Wujin People's HospitalWujin Hospital Affiliated with Jiangsu UniversityChangzhouJiangsu213000China

Objective:To estimate the bone protective effect of alpinumisoflavone,a natural prenylated isoflavonoid,against glucocorticoid-induced osteoporosis in ***:Male Wistar rats received intramuscular administration of dexamethasone(4 mg/mL)at a dose level of 7 mg/kg for 5 weeks,and then alpinumisoflavone(5,10,and 15 mg/kg)and alendronate(2 mg/kg)from 2 *** body weight and organ weight(femoral,vagina,and uterus)were *** analysis,bone turnover markers,bone parameters,oxidative stress parameters,and inflammatory cytokines were *** expressions of related genes were also ***:Alpinumisoflavone remarkably boosted body weight and organ weight(ureters and vagina),improved microCT analysis parameters,and boosted levels of bone ***,alpinumisoflavone considerably(P<0.001)restored the level of bone turnover markers and oxidative stress parameters,remarkably suppressed the level of cytokines such as interleukin-1β,interleukin-6,tumor necrosis factor-α,and increased transforming growth factor-βand insulin-like growth *** also significantly restored the osteoprotegerin(OPG,RANKL,and OPG/RANKL ratio)levels and the mRNA expression of Caspase(3,6,7,9),BMPs,OPN,ALP,RUNX2,and ***:The current result suggests the bone protective effect of alpinumisoflavone against glucocorticoid-induced osteoporosis in rats.

关键词： Osteoporosis Alpinumisoflavone Bone parameters Inflammation Oxidative stress

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含裂纹纳米板振动问题的哈密顿体系方法

计算力学学报 2024年第1期41卷 66-72页

作者：屈建龙周震寰徐新生大连理工大学工程力学系工业装备结构分析优化与CAE软件全国重点实验室大连116024

基于裂纹处范德华力效应,采用非局部弹性理论构造纳米板模型,并通过导入哈密顿体系建立含裂纹纳米板振动问题的对偶正则控制方程组。在全状态向量表示的哈密顿体系下,将含裂纹纳米板的固有频率和振型问题归结为广义辛本征值和本征解问... 详细信息

基于裂纹处范德华力效应,采用非局部弹性理论构造纳米板模型,并通过导入哈密顿体系建立含裂纹纳米板振动问题的对偶正则控制方程组。在全状态向量表示的哈密顿体系下,将含裂纹纳米板的固有频率和振型问题归结为广义辛本征值和本征解问题。利用哈密顿体系具有的辛共轭正交关系,得到问题解的级数解析表达式。结合边界条件,得到固有频率与辛本征值的代数方程关系式,进而直接给出固有频率的表达式。数值结果表明,非局部尺寸参数和裂纹长度对纳米板振动的各阶固有频率有直接的影响。对比表明,辛方法是准确且可靠的,可为工程应用提供依据。

关键词：哈密顿体系含裂纹纳米板非局部理论振动固有频率

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Determining a Multi-layered Fluid-solid Medium from the Acoustic Measurements

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Acta Mathematicae Applicatae Sinica 2020年第1期36卷 67-73页

作者： Yan-li CUI Feng-long qu School of Mathematics and Information Sciences Yantai UniversityYantai 264005China

Consider the inverse problem of recovering a multi-layered fluid-solid medium from many acoustic measurements corresponding to time-harmonic acoustic plane *** prove that both the supports of the embedded solid obstacle and the surrounding layered fluid medium can be uniquely identified by means of acoustic far-field pattern for all incident wave fields at a fixed *** proof is based on the constructions of some well-posed partial differential equation systems in sufficiently small domains combined with the a priori estimates for the solutions of the forward scattering problem.

关键词： inverse scattering fluid-solid interaction multi-layered medium uniqueness

基于奥马哈系统的延伸护理结合微信健康教育在糖尿病足患者中的应用效果

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反射疗法与康复医学 2024年第4期5卷 163-165,169页

作者：罗慧敏渠龙济宁市兖州区人民医院内分泌科山东济宁272000 济宁市兖州区人民医院急诊科山东济宁272000

目的探讨基于奥马哈系统的延伸护理结合微信健康教育在糖尿病足患者中的应用效果.方法选取2020年12月—2023年8月济宁市兖州区人民医院收治的84例糖尿病足患者为研究对象,按照随机数字表法将其分为对照组和观察组,每组42例.对照组实施... 详细信息

目的探讨基于奥马哈系统的延伸护理结合微信健康教育在糖尿病足患者中的应用效果.方法选取2020年12月—2023年8月济宁市兖州区人民医院收治的84例糖尿病足患者为研究对象,按照随机数字表法将其分为对照组和观察组,每组42例.对照组实施常规护理,观察组于对照组基础上实施基于奥马哈系统的延伸护理结合微信健康教育.比较两组血糖水平、足部知识掌握情况、生活质量.结果观察组足部知识总掌握率高于对照组,差异有统计学意义(P<0.05);干预后,观察组糖化血红蛋白、餐后2h血糖、空腹血糖、糖尿病患者生存质量特异性量表评分均低于对照组,组间差异统计学意义(P<0.05).结论在糖尿病足患者中应用基于奥马哈系统的延伸护理结合微信健康教育效果显著,可促使患者掌握足部相关知识,更好地控制血糖,改善生活质量.

关键词：糖尿病足微信健康教育延伸护理奥马哈系统血糖足部知识掌握情况

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基于改进蚁群算法的高精度水声定位航路规划

声学技术 2024年第3期43卷 323-334页

作者：刘翰富曲龙秦莎莎商志刚喻敏哈尔滨工程大学水声技术全国重点实验室黑龙江哈尔滨150001 海洋信息获取与安全工信部重点实验室(哈尔滨工程大学)工业和信息化部黑龙江哈尔滨150001 哈尔滨工程大学水声工程学院黑龙江哈尔滨150001 中国船舶集团有限公司第七〇三研究所黑龙江哈尔滨150001 杭州应用声学研究所浙江杭州310012 武汉理工大学船海与能源动力工程学院湖北武汉430070

精确的水声定位是进行海洋资源勘探、海底管道敷设、海洋地形测绘等海洋开发活动的前提。其中一类典型的定位目标是可发射周期声信号的固定信标。文章利用单个自主式水下航行器(Autonomous Underwater Vehicle,AUV)对该类目标进行定位,... 详细信息

精确的水声定位是进行海洋资源勘探、海底管道敷设、海洋地形测绘等海洋开发活动的前提。其中一类典型的定位目标是可发射周期声信号的固定信标。文章利用单个自主式水下航行器(Autonomous Underwater Vehicle,AUV)对该类目标进行定位,其中一个关键问题是AUV的航路规划。传统的航路规划方法通常研究避障和路径长度最优化,未考虑定位问题的特殊性,而最终的定位精度是与航路息息相关的。因此,传统的航路规划方法容易导致所规划航路的定位精度较差。针对这一问题,文章在传统蚁群算法的基础上,首先引入Bresenham画圆算法规划圆形航路,保持定位目标处于AUV舷侧声呐视野范围内,避免信号缺失;同时在信息素设计中加入了定位精度因子,使得所规划的航路能充分考虑到定位精度。仿真实验表明,文中所提出的方法可以在传统航路规划避障能力、路径长度优化能力的基础上兼顾定位任务,提高针对声信标类目标的定位精度及定位鲁棒性。

关键词：航路规划蚁群算法水声定位水下无人航行器

The Global Existence of Solutions for Two Classes of Chemotaxis Models

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Acta Mathematicae Applicatae Sinica 2014年第3期30卷 555-570页

作者： Feng-long qu Ya-ping WU School of Mathematics and Informational Science Yantai University Department of Mathematics Capital Normal University

This paper is concerned with the global existence and uniform boundedness of solutions for two classes of chemotaxis models in two or three dimensional spaces. Firstly, by using detailed energy estimates, special interpolation relation and uniform Gronwall inequality, we prove the global existence of uniformly bounded solutions for a class of chemotaztic systems with linear chemotactic-sensitivity terms and logistic reaction terms. Secondly, by applying detailed analytic semigroup estimates and special iteration techniques, we obtain the global existence of uniformly bounded solutions for a class of chemotactic systems with nonlinear chemotacticsensitivity terms, which extends the global existence results of [6] to other general cases.

关键词： chemotactic systems global existence uniformly boundedness energy estimates.

不同冷却速率对GH4151高温合金定向凝固组织及元素偏析的影响

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材料热处理学报 2024年第4期45卷 87-94页

作者：黄科杰孙悦张麦仓唐超吕少敏曲敬龙北京科技大学材料科学与工程学院北京100083 北京钢研高纳科技股份有限公司北京100081

为了进一步降低合金凝固偏析程度和优化真空自耗冶炼(VAR)工艺,利用液态金属冷却法(LMC)对GH4151合金进行定向凝固实验,采用光学显微镜、扫描电镜及电子探针等研究了冷却速率对GH4151合金定向凝固组织及元素偏析的影响。结果表明:随着... 详细信息

为了进一步降低合金凝固偏析程度和优化真空自耗冶炼(VAR)工艺,利用液态金属冷却法(LMC)对GH4151合金进行定向凝固实验,采用光学显微镜、扫描电镜及电子探针等研究了冷却速率对GH4151合金定向凝固组织及元素偏析的影响。结果表明:随着冷却速率的增加,一次枝晶间距λ_(1)及二次枝晶间距λ_(2)均逐渐减小,两者与冷却速率间满足相似的函数关系。而且,枝晶干及枝晶间γ′相尺寸也随冷却速率的增加逐渐减小,组织均匀性提高。对凝固组织元素成分分布的电子探针分析表明:GH4151合金主要偏析元素为W、Nb、Ti,偏离程度在20%以上,且3种元素显微偏析程度均随冷却速率的增加而加重,原因在于随着冷却速率增加,凝固前沿固相层可供溶质扩散的时间减少,扩散效果减弱。

关键词： GH4151高温合金冷却速率定向凝固凝固组织显微偏析

Microstructure evolution characterization of Ni-based GH4720Li superalloy during strain-controlled fatigue at 550℃

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Journal of Iron and Steel Research International 2021年第7期28卷 901-909页

作者： Xing-fei Xie Jing-long qu Jin-hui Du Zhong-nan Bi Gaona Aero Material Co. Ltd.Beijing 100081China High Temperature Materials Research Institute Central Iron and Steel Research InstituteBeijing 100081China

High-temperature fatigue property of Ni-based GH4720Li superalloy at 550℃has been investigated at maximum strain from 0.8%to 1.1%.Microstructural characterization and oxidation behavior of superalloy during high-temperature fatigue have been analyzed by transmission electron microscopy and scanning transmission electron *** results show that a stable response following a slight cyclic hardening during initial cycles was revealed at the maximum strain from 0.8%to 1.0%.The stable response decreased with an increase in maximum *** cyclic hardening was observed at the maximum strain of 1.1%.There is difference in dislocation substructures between primary γ'precipitates and γ *** cell and mechanical twin were formed in the interior of primary γ'precipitates and γ *** primary γ'precipitate interface would migrate toward the interior of primary γ'precipitates along twin boundaries,leading to instability of primary γ'*** secondary γ'depleted zone was distinctly generated near the surface due to the decomposi-tion of secondary γ'*** crack initiation and propagation during high-temperature fatigue were found inside the secondary γ'depleted *** primary γ'precipitates could effectively hinder the crack ***-rich oxide films(Al_(2)O_(3))were initially produced at crack tips,because the rate of diffusion of Al was relatively higher than that of other elements at crack tips.

关键词： Ni-based superalloy High-temperature fatigue Transmission electron microscopy Scanning transmission electron microscopy Fatigue crack tip Oxide