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双层车体装配工艺及焊接方法研究
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作者 田新莉 毛茂 +2 位作者 刘宇航 吴兆星 张绍辉 《焊接技术》 2021年第3期48-50,共3页
分析了一种新型的双层车体组成结构,研究了一种铝合金双层车体装配工艺方法,提出了一种适用于此新型结构、并保证双层箱体尺寸要求的焊接方法。
关键词 双层车体 装配方法 焊接方法
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双层不锈钢车体焊接结构设计 被引量:4
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作者 张硕韶 王力 《电焊机》 2021年第12期83-89,I0007,共8页
按照美国客运轨道车辆的设计标准,采用符合美标的低碳不锈钢和低合金高强钢进行车体结构设计,其中双层不锈钢车体点焊焊接接头的设计符合AWD D17.2和AWS C1.1焊接标准,弧焊焊接接头形式根据不同板厚分别按照AWS D1.1和AWS D17.2进行设... 按照美国客运轨道车辆的设计标准,采用符合美标的低碳不锈钢和低合金高强钢进行车体结构设计,其中双层不锈钢车体点焊焊接接头的设计符合AWD D17.2和AWS C1.1焊接标准,弧焊焊接接头形式根据不同板厚分别按照AWS D1.1和AWS D17.2进行设计。车体各大部件和车体总成适合模块化制造,焊接变形小,侧墙、侧顶、端墙等可视表面平整度好,能满足车体优美、平滑的外观要求。车体静强度、屈曲计算结果和试验数据对比分析表明,试验车体的强度符合美国客运轨道车辆的设计标准APTA PR-CS-S-034-99,产品安全可靠。 展开更多
关键词 双层不锈钢车体 结构设计 焊接接头 弹性极限
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双层铝合金车体焊接结构设计 被引量:1
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作者 张硕韶 于金朋 张锦华 《电焊机》 2017年第6期88-94,共7页
依照双层铝合金车体总体设计规范的要求,以车辆动态包络线作为车体断面设计的约束条件,进行车体的三维设计和详细结构设计,按照EN 15085的焊接标准要求优化双层铝合金车体焊接结构,同时对车体母材与焊接材料进行优化匹配。经车体静强度... 依照双层铝合金车体总体设计规范的要求,以车辆动态包络线作为车体断面设计的约束条件,进行车体的三维设计和详细结构设计,按照EN 15085的焊接标准要求优化双层铝合金车体焊接结构,同时对车体母材与焊接材料进行优化匹配。经车体静强度试验验证,优化后的焊接接头型式减少了车体大部件和车体总成的焊接变形,适合车体的模块化制造需求。通过计算车体静强度,证明250 km/h双层铝合金试验车体的强度符合EN 12663要求,产品的安全性、可靠性满足欧洲铁路客车强度规范。 展开更多
关键词 双层铝合金车体 结构优化 焊接接头 静强度
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北美双层不锈钢车体侧墙焊接工艺研究
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作者 安吉 宋杰 +3 位作者 高昆 陈绍亭 曹思农 李学鹏 《焊接技术》 2021年第10期46-48,共3页
文中介绍了北美双层不锈钢车体侧墙焊接工艺的研究及成果。通过对侧墙结构、工艺难点、焊接变形的分析,制订出适合侧墙的焊接工艺,有效地控制了焊接变形,提高了侧墙外观的平面度与美观性,达到了设计意图。
关键词 双层不锈钢车体 侧墙 焊接工艺 焊接变形
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基于美国标准的轨道客车双层不锈钢车体焊接工艺研究
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作者 张建辉 邬瑞峰 +2 位作者 尹晓亮 高昆 宋杰 《焊接技术》 2023年第1期88-93,共6页
北美双层客车不锈钢车体因其强度和刚度要求高,且主结构由弧焊骨架和点焊蒙皮组焊而成,以及车体外表面为无涂装形式,车体部件尺寸、焊接质量和外观质量成为制造难点。基于美国标准,进行双层不锈钢车体焊接工艺技术研究,通过更新焊接工... 北美双层客车不锈钢车体因其强度和刚度要求高,且主结构由弧焊骨架和点焊蒙皮组焊而成,以及车体外表面为无涂装形式,车体部件尺寸、焊接质量和外观质量成为制造难点。基于美国标准,进行双层不锈钢车体焊接工艺技术研究,通过更新焊接工艺方法,优化焊接工艺参数,采用新焊接技术和样板等技术,改善了各大部件特殊焊缝和外露焊缝成形,提高了双层不锈钢车体焊接质量;通过优化焊接工艺流程、调整焊接顺序、增加工件放量、调整预置反变形量、使用新调修方法等技术,各大部件的焊接变形得到有效控制,保证了车体的关键特性尺寸和外观质量。 展开更多
关键词 美国标准 双层不锈钢车体 焊接工艺
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liver and the defects of cholesterol and bile acids biosynthesis: rare disorders many diagnostic pitfalls 被引量:2
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作者 Gaetano Corso Antonio Dello Russo Monica Gelzo 《World Journal of Gastroenterology》 SCIE CAS 2017年第29期5257-5265,共9页
In recent decades, biotechnology produced a growth of knowledge on the causes and mechanisms of metabolic diseases that have formed the basis for their study, diagnosis and treatment. Unfortunately, it is well known t... In recent decades, biotechnology produced a growth of knowledge on the causes and mechanisms of metabolic diseases that have formed the basis for their study, diagnosis and treatment. Unfortunately, it is well known that the clinical features of metabolic diseases can manifest themselves with very different characteristics and escape early detection. Also, it is well known that the prognosis of many metabolic diseases is excellent if diagnosed and treated early. In this editorial we briefly summarized two groups of inherited metabolic diseases, the defects of cholesterol biosynthesis and those of bile acids. Both groups show variable clinical manifestations but some clinical signs and symptoms are common in both the defects of cholesterol and bile acids. The differential diagnosis can be made analyzing sterol profiles in blood and/or bile acids in blood and urine by chromatographic techniques(GC-MS and LC-MS/MS). Several defects of both biosynthetic pathways are treatable so early diagnosis is crucial. Unfortunately their diagnosis is made too late, due either to the clinical heterogeneity of the syndromes(severe, mild and very mild) that to the scarcity of scientific dissemination of these rare diseases. Therefore, the delay in diagnosis leads the patient to the medical observation when the disease has produced irreversible damages to the body. Here, we highlighted simple clinical and laboratory descriptions that can potentially make you to suspect a defect in cholesterol biosynthesis and/or bile acids, as well, we suggest appropriate request of the laboratory tests that along with common clinical features can help to diagnose these defects. 展开更多
关键词 CHOLESTEROL Bile acids Liver metabolism Gas chromatography coupled to mass spectrometry Liquid chromatography coupled to tandem mass spectrometry
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日本推出E2—1000型新干线列车
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《电气牵引》 2003年第1期22-22,共1页
关键词 E2-1000型 新干线列车 双层全铝制车体外壳 东日本铁路公司
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Evaluation of the hepatoprotective and antioxidant activities of Rubus parvifolius L. 被引量:7
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作者 Jie GAO Cui-rong SUN +5 位作者 Jie-hong YANG Jian-mei SHI Yue-guang DU Yu-yan ZHANG Jin-hui LI Hai-tong WAN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第2期135-142,共8页
The hepatoprotective and antioxidant activities of the n-butanol extract of Rubus parvifolius L. (RPL), a widely used medicinal plant, were evaluated. Results demonstrated that RPL extract possessed pronounced hepat... The hepatoprotective and antioxidant activities of the n-butanol extract of Rubus parvifolius L. (RPL), a widely used medicinal plant, were evaluated. Results demonstrated that RPL extract possessed pronounced hepatoprotective effects against carbon tetrachloride (CCI4)-induced hepatic injury in mice, which was at least partially attributed to its strong antioxidant capacity. Treatment with RPL extract markedly attenuated the increases in serum alanine ami- notransferase (ALT) and aspartate aminotransferase (AST) levels caused by CCI4 intoxication. It also significantly prevented the decrease in superoxide dismutase (SOD) activity and the increase in malondialdehyde (MDA) content of liver tissue. Meanwhile, histopathological changes of hepatic damage were also remarkably ameliorated. Phytochemical analysis based on high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) revealed the presence of various phenolic compounds, including caffeic acid conjugates, ellagic acid glycosides, and flavonol glycosides, which might be responsible for the hepatoprotective and antioxidant activities of RPL. 展开更多
关键词 Rubus parvifofius L. High-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) Hepatoprotective activity Antioxidant activity
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Analysis of 19-nortestosterone residue in animal tissues by ion-trap gas chromatography-tandem mass spectrometry
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作者 Jin-qing JIANG Lei ZHANG +6 位作者 Guang-ling LI Hai-tang ZHANG Xue-feng YANG Jun-wei LIU Ren-feng LI Zi-liang WANG Jian-hua WANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第6期460-467,共8页
A rapid sample treatment procedure for the gas chromatography-tandem mass spectrometry (GC-MS) determination of 19-nortestosterone (19-NT) in animal tissues has been developed. In our optimized procedures, enzymat... A rapid sample treatment procedure for the gas chromatography-tandem mass spectrometry (GC-MS) determination of 19-nortestosterone (19-NT) in animal tissues has been developed. In our optimized procedures, enzymatic hydrolysis with β-glucuronidase from Escherichia coliwas performed in an acetate buffer (pH 5.2, 0.2 mol/L) Next, the homogenate was mixed with methanol and heated at 60℃ for 15 min, then placed in an ice-bath at -18℃ for 2 h. After liquid-liquid extraction with n-hexane, the analytes were subjected to a normal-phase solid phase ex- traction (SPE) C18 cartridge for clean-up. The dded organic extracts were derivatized with heptafluorobutydc anhydride (HFBA), and then the products were injected into GC-MS. Using electron impact mass spectrometry (El-MS) with positive chemical ionization (PCI), four diagnostic ions (mlz 666, 453, 318, and 306) were determined. A standard calibration curve over the concentration range of 1-20 ng/g was reached, with Y=467084X-68354 (R^2=0.9997) for 19-NT, and the detection limit was 0.3 ng. When applied to spiked samples collected from bovine and ovine, the recoveries ranged from 63% to 101% with relative standard deviation (RSD) between 2.7% and 8.9%. The procedure is a highly efficient, sensitive, and more economical method which offers considerable potential to resolve cases of suspected nandrolone doping in husbandry animals. 展开更多
关键词 19-Nortestosterone (19-NT) Gas chromatography-tandem mass spectrometry (GC-MS) Animal tissues
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