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Effect of Austempering–Partitioning on the Bainitic Transformation and Mechanical Properties of a High-Carbon Steel

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Acta Metallurgica Sinica(English Letters) 2015年第5期28卷 614-618页

作者： Bo Han Lei Chen su-jun wu School of Materials Science and Engineering Beihang University

The 1.1C-1.5Si-1.1Mn1.4Cr-0.5Mo-0.6Al-0.6Co （in wt%） steel was treated, respectively, by isothermal austempering process and newly developed austempering-partitioning-tempering process （A-P-T）. After austempering at 250, 280 and 300 ℃ for 38, 20 and 10 h, respectively, the sample microstructures were composed of bainitic ferrite plates and film-like retained austenite with thicknesses between 60 and 150 nm. The highest tensile strength of 2003 MPa and hardness value of 53.9 HRC were obtained for the steel after austempering at 250 ℃ for 38 h, resulting from the combining effect of super-saturated martensite decarburization and stabilization of bainitic formation. After A-P-T treating （heated at 300 ℃ for 8 h following water cooling, and then heated at 300 ℃ for 2 h following air cooling）, bamboo leaf-like martensite, primary and secondary bainites and retained austenite were observed. The thickness of the secondary bainitic ferrite plates formed during partitioning is much smaller than that of the primary bainite formed during 300 ℃ austempering. Samples subjected to A-P-T treatment showed improvement in ductility compared to that subjected to austempering.

关键词： High-carbon alloy steel Low-temperature bainite Microstructure Mechanical properties Austempering-partitioning-tempering

Effect of strain rate and temperature on the serration behavior of SA508-Ⅲ RPV steel in the dynamic strain aging process

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Journal of Iron and Steel Research International 2018年第7期25卷 767-775页

作者： Xue Bai su-jun wu Li-jun Wei Shuai Luo Xie Xie Peter K. Liaw School of Materials Science and Engineering Beihang University Beijing 100191 China Department of Materials Science and Engineering The University of Tennessee Knoxville TN 37996 USA Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang University Beijing 100191 China

Dynamic strain aging （DSA） effect on SA508-III reactor pressure vessel （RPV） steel was investigated. The SA508-III RPV steel was subjected to tension tests at different strain rates （1.1× 10-5 s-1 and 6.6× 10-5 s-1） and different temperatures （500 and 550 ℃） to evaluate the influence of strain rate and temperature on the serrated flow behavior, which is the repetitive and discontinuous yielding phenomenon on the stress-strain curves. The higher temperature leads to the higher density of precipitates, M23C6 carbides and needle-like Mo2C carbides. It was found that the samples under tension test of 6.6 × 10-5 s-1 and 500 ℃ possess superior mechanical properties and mainly show A-type serrations on the tension test curves. Then, the local regress method was used to filter the DSA curves, thus to show the real trend of the curves. It has been found that the less time of interaction between dislocations and precipitates under higher strain rates leads to a higher strength of the sample. The more tiny-stress drops on the 550 ℃ serration curve can be attributed to the hardening phase, M23C6 carbides and needle-like Mo2C carbides. The higher percentage of the small stress drops on the serration curves represents the higher mechanical strength.

关键词： Reactor pressure vessel steel SA508-Ⅲ steel Dynamic strain aging Serration behavior

Serrated flow behavior of GH536 superalloy under different loading rates at room temperature

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Rare Metals 2024年第5期43卷 2317-2323页

作者： Wen-Xiang Gao Dong Ma Li-Li Zhao Fan Ye Ling Shao su-jun wu School of Materials Science and Technology Beihang UniversityBeijing100091China

Serrated flow phenomenon has been widely observed among different metals due to the potential influence on their *** tensile tests of nickel-based superalloy GH536 were carried out at loading rates of 0.06,0.60,3.60,and 36.00 mm·min^(-1)at room temperature,*** tensile stress-strain curves demonstrate repetitive and discontinuous yielding behavior,namely serrated *** is observed that the stress-strain curves were dominated by type B serration,and original annealing twin boundaries(TBs)were distorted to various degrees under comparatively different lower tensile *** contrast,the TBs almost disappear,and the type B serrations become smoother and regular under the higher loading *** phenomenon can be attributed to the interactions between TBs and dislocations during tensile *** effects of the mobile and immobile dislocations illustrate the unsteady amplitude of serrations observed in stress-strain *** electron microscope images of tested pieces reveal the interaction of dislocation and TB,with dislocation tangling around the TBs.

关键词： Nickel-based superalloy Serrations Twin boundaries Deformation mechanism

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交易成本与制度创新

财经理论与实践 2005年第5期26卷 8-11页

作者：苏武俊广东商学院会计学院广东广州510320

国有企业通过许多途径,包括采用先进的技术、吸引优秀的管理人才、运用科学的管理方法,使生产成本大大降低了。而制度所引起的交易成本,由于在改革中没有引起足够的重视,因而交易成本未从根本上下降。通过对影响国有企业效率的内、外部... 详细信息

国有企业通过许多途径,包括采用先进的技术、吸引优秀的管理人才、运用科学的管理方法,使生产成本大大降低了。而制度所引起的交易成本,由于在改革中没有引起足够的重视,因而交易成本未从根本上下降。通过对影响国有企业效率的内、外部制度的分析研究,可寻求降低交易成本的方法。

关键词：交易成本制度分析国企改革

Comparative analysis of early and middle outcomes of the arterial switch operation in children with complete transposition of the great arteries with ventricular septal defect and severe pulmonary artery hypertension

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Chinese Medical Journal 2013年第11期126卷 2074-2078页

作者： LIU Cheng-hu su jun-wu LI Zhi-qiang FAN Xiang-ming CHEN Yan HE Yan LIUYing-long Department of Pediatric Cardiology Beijing An Zhen HospitalAffiliated to Capital Medical University Beijing Institute of HeartLung and Blood Vessel Diseases Beijing 100029 China

Background The best age for the arterial switch operation （ASO） in complete transposition of great arteries with ventricular septal defect is usually considered to be within six months. This is because of severe pulmonary arterial hypertension and pulmonary arterial obstructive pathological changes. There are few reports on ASO surgery in children older than three years old. Methods We studied 41 children, including 24 males and 17 females, from January 2010 to December 2011. They were divided into three groups by operation age; 15 patients were 〈1 year old, 13 were 1-3 years old, and 13 were 〉3 years old. Associated cardiac abnormalities included patent ductus arteriosus in six cases, atrial septal defect in five cases, and mitral regurgitation in two cases. All the patients had echocardiography before the operation. Seventeen patients underwent a coronary computed tomography examination and five patients underwent right heart catheterization. All ASO surgeries were performed under inhalation anesthesia and hypothermic cardiopulmonary bypass. Results Three operative deaths occurred. Two were in the 〈1 year old group, who died from severe postoperative low cardiac output. The other was two years old and died of postoperative multiple organ failure. There was no significant difference in postoperative mortality and the recent mid-term survival rate among the three groups. Thirty-eight cases were followed up for an average of 11.2 months, ranging 6-20 months. One seven years old patient died of acute diarrhea and electrolyte disturbance arrhythmia caused by food poisoning. Three patients more than three years old still had residual pulmonary arterial hypertension. Conclusion Children older than three years old can still undergo the ASO procedure, but residual pulmonary hypertension is present.

关键词： transposition of the great arteries arterial switch operation pulmonary arterial hypertension congenital heart disease

Clinical results of combined palliative procedures for cyanotic congenital heart defects with intractable hypoplasia of pulmonary arteries

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Chinese Medical Journal 2013年第9期126卷 1678-1682页

作者： FAN Xiang-ming ZHU Yao-bin su jun-wu ZHANG Jing LI Zhi-qiang XU Yao-qiang LI Xiao-feng LIU Ying-long Department of Pediatric Heart Center Department of Children Heart Center Beijing Anzhen Hospital Capital Medical University Beijing 100029 China

Background Congenital heart defects with intractable hypoplasia of the pulmonary arteries without intercourse or with intercourse stenosis is unsuitable for surgical correction or regular palliative procedures. We reported our experience with combined palliative procedures for congenital heart defects with intractable hypoplasia pulmonary arteries. Methods From 2001 to 2012, a total of 41 patients with cyanotic congenital heart defects and intractable hypoplasia of the pulmonary arteries underwent surgical procedures. From among them, 31 patients had pulmonary atresia with ventricular septal defect （VSD） and the other 10 cases had complicated congenital heart defects with pulmonary stenosis. Different kinds of palliative procedures were performed according to the morphology of the right and left pulmonary arteries in every patient. If the pulmonary artery was well developed, a Glenn procedure was performed. A modified Blalock-Taussig shunt or modified Waterston shunt was performed if pulmonary arteries were hypoplastic. If the pulmonary arteries were severely hypoplastic, a Melbourne shunt was performed. Systemic pulmonary artery shunts were performed bilaterally in 25 cases. A systemic-pulmonary shunt was performed on one side and a Glenn procedure was performed contralaterally in 16 cases. Major aortopulmonary collateral arteries were unifocalized in six cases, ligated in two cases and interventionally embolized in two cases. There was one early death because of cardiac arrest and the hospital mortality was 2.4%. Results Five patients suffered from postoperative low cardiac output syndrome, three had perfusion of the lungs, and two pulmonary infections. Systemic pulmonary shunts were repeated after the original operation in three cases due to the occlusion of conduits. The mean follow-up time was 25 months. The pre- and the post-operation left pulmonary indices were （8.13±3.68） vs. （14.9±6.21） mm2/m2. The pre- and post-operation right pulmonary indices were （12.7±

关键词： congenital heart disease hypoplasia of pulmonary artery palliation

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人工智能背景下实现信息化测绘的方法研究

自动化与仪表 2021年第10期36卷 63-68页

作者：苏俊武中国冶金地质总局第三地质勘查院太原030002

针对现有的信息化测绘系统勘测精度低、计算速度缓慢等问题,提出了一个新的信息化测绘系统,该系统结合了无人驾驶飞行器(unmanned aerial vehicle,UAV)和无人地面车辆(unmanned ground vehicle,UGV)在3D未知环境中进行自主探索、测绘和... 详细信息

针对现有的信息化测绘系统勘测精度低、计算速度缓慢等问题,提出了一个新的信息化测绘系统,该系统结合了无人驾驶飞行器(unmanned aerial vehicle,UAV)和无人地面车辆(unmanned ground vehicle,UGV)在3D未知环境中进行自主探索、测绘和导航。该系统实现了一种新的两层探测策略,将感知任务分解为粗勘测层和细映射层。粗探测利用UGV进行快速自主探测和同步定位与绘图(simultaneous localization and mapping,SLAM),生成粗环境模型,为后续无人机进行互补3D精细绘图提供导航参考。两层共享一个新的优化探测路径规划和导航框架,该框架通过基于OctoMap的体运动规划接口提供最优探测路径和绘图工作。通过实验验证了该系统的有效性,为导航任务提供了优化感知。

关键词：人工智能无人机无人地面车辆信息化测绘

超声心动图诊断儿童心脏肿瘤24例病例系列报告

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中国循证儿科杂志 2020年第3期15卷 196-200页

作者：杨爽耿斌李文秀苏俊武吴江首都医科大学附属北京安贞医院儿童心血管病中心北京100029

目的总结超声心动图诊断儿童及青少年心脏肿瘤的特点及临床治疗经验。方法纳入2013年1月至2020年1月于首都医科大学附属北京安贞医院儿童心血管病中心住院治疗的心脏肿瘤患儿,对其超声心动图表现及临床资料进行回顾性分析。结果 24例患... 详细信息

目的总结超声心动图诊断儿童及青少年心脏肿瘤的特点及临床治疗经验。方法纳入2013年1月至2020年1月于首都医科大学附属北京安贞医院儿童心血管病中心住院治疗的心脏肿瘤患儿,对其超声心动图表现及临床资料进行回顾性分析。结果 24例患儿进入本文分析,20例行肿瘤完整切除术,4例行肿瘤部分切除术。术后病理显示良性病变19例(79.2%),恶性病变1例(4.2%),生物学行为未明性肿瘤4例(16.7%);黏液瘤7例,横纹肌瘤6例,炎性肌纤维母细胞瘤4例,纤维瘤3例,纤维肉瘤、畸胎瘤、血管瘤和血栓各1例。心脏肿瘤发生部位以右心室、左心房多见。超声诊断与手术后病理诊断符合率29.2%(7/24)。黏液瘤超声表现特异性强,超声与手术后病理诊断符合率85.7%(6/7),黏液瘤的超声特征性表现包括:低至中等回声,分叶状,形态不规则,结构松散,活动度大,均有蒂附着;形态会随心脏的收缩和舒张改变,舒张期瘤体不同程度嵌入房室瓣口,引起房室瓣继发狭窄。结论儿童心脏肿瘤以良性肿瘤多见,病理类型以黏液瘤、横纹肌瘤为主。黏液瘤超声诊断符合率高。

关键词：心脏肿瘤超声心动图儿童外科治疗

Refractory lipoatrophy treated with autologous whole blood injection:A case report

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World Journal of Clinical Cases 2025年第2期13卷 33-38页

作者： Wonnam Kim jun su Park En Hyung Kim Department of Pharmacology School of Korean MedicinePusan National UniversityYangsan 50612GyeongnamSouth Korea Department of Dermatology College of MedicineChungbuk National UniversityCheongju 28644ChungbukSouth Korea Department of Dermatology Chungbuk National University HospitalCheongju 28644ChungbukSouth Korea

BACKGROUND Intramuscular corticosteroid injection may cause adverse effects such as dermal and/or subcutaneous atrophy,alopecia,hypopigmentation,and *** cutaneous atrophy can spontaneously resolve,several treatment options have been suggested for this *** suMMARY In this paper,we report a case of corticosteroid injection induced lipoatrophy treated with autologous whole blood(AWB)injection,as the condition had been unresponsive to fractional laser therapy.A 29-year-old female patient visited the dermatology clinic complaining of skin depression on her right buttock area,which had appeared six months *** had been only subtle improvement at the margins after fractional CO_(2) laser treatment;therefore,after obtaining informed consent from the patient,AWB treatment was *** month after the first AWB injection,the size and depth of the lesion had noticeably improved,and a slight improvement was also observed in *** Close observation is the initial treatment of choice for steroid induced skin atrophy;however,for patients in need of immediate cosmetic improvement,AWB injection may be a safe and cost-effective alternative.

关键词： Atrophy Corticosteroid subcutaneous fat Autologous whole blood injection Laser therapy Case report