AP1000汽水分离再热器异形管板制造技术研究

AP1000核电站汽水分离再热器一级再热器管板为长圆形异形管板,与以往产品相比,制造精度高、清洁控制严格。按照管板的制造工艺流程,详细论述了一级再热器管板镍基合金堆焊、热处理、钻孔加工及清洁控制等关键技术,为类似核电站产品的制造提供了借鉴。     

乙苯蒸汽过热器国产化研制

针对乙苯蒸汽过热器在使用过程中出现的滑动管板变形、换热管与热端管板连接接头泄漏等问题，文章从结构和制造两方面分析了它们产生的原因。在国产化研制过程中，从换热管与热端管板的连接方式、滑动管板滑动结构等方面加以改进，并在制造过程中加强质量控制，制造出了结构设计合理、制造质量优良的产品。     

AP1000核电站汽水分离再热器制造技术

通过AP1000核电站汽水分离再热器中再热器的研制,阐述了再热器蒸汽室、管板、管束支撑及总装在制造过程中的关键工序及制造难点,解决了封头组焊、管板堆焊、深孔加工、翅片管穿管等工艺难题,为类似产品的制造提供借鉴。     

双管板换热器的制造要点

根据双管板换热器的特殊结构,介绍了用模拟管板进行胀接工艺评定的方法以及管板加工、强度胀接、管板组装、压力试验等方面的制造要点,确定了影响双管板强度胀接致密性的关键因素在于管板管孔、胀槽的同心度和槽的粗糙度以及合适的胀接参数。     

管壳式双管板冷油器的设计及制造

冷油器在机械制造、电力及化工等润滑领域内应用十分广泛,是不可缺少的换热设备之一。本文结合工程实际,从双管板结构选型、管板及冷却管材料选择、管板计算、冷油器加工、制造及装配等方面对管壳式双管板冷油器的设计及制造进行了介绍。     

CPR1000蒸汽发生器支撑板主要工艺流程

蒸汽发生器支撑板加工质量直接影响后续穿管、焊管及胀管可实施性及难易程度,是蒸汽发生器制造中的关键环节。根据实际制造过程中汇总的经验及相关问题,对CPR1000蒸汽发生器中支撑板钻孔、拉孔及倒角流程进行了阐述,为以后支撑板的制造提供参考。     

双管板换热器管束的改进

针对双管板式蒸汽发生器在操作和制造中存在的问题，对管板材料，管子和管板的连接结构以及制造工艺进行了改进，效果良好。     

废热锅炉的研制

通过废热锅炉的研制，阐述了制造过程中的管板堆焊、钻孔、换热管对接、热处理等关键工序等制造难点的控制。     

AP1000核电机组高压加热器制造技术

通过AP1000核电机组高压加热器的研制,阐述了核电高压加热器水室、管系、外壳及总装在制造过程中的关键工序及制造难点,解决了管孔加工、管子-管板胀接、管子-管板焊接、清洁控制等工艺难题。     

CAP1400蒸汽发生器关键制造技术

根据第三代非能动压水堆(CAP1400)水堆核电蒸汽发生器制造过程中积累的经验并结合其他压水堆型核电蒸汽发生器的制造经验,介绍了CAP1400蒸汽发生器的结构特点,并分别对制造过程中的一些关键制造技术,如管板一次侧镍基堆焊、管板深孔钻、内套筒的装配、管束穿管、液压胀管和水室封头焊接等进行详细的阐述,为后续压水堆型核电蒸汽发生器的制造提供经验参考。     

Histochemical and ultrahistochemical localization of heavy metals in calf organs

Cadmium, zinc, selenium, and copper were administered, singly or in combination, orally or subcutaneously. Experiment I included 32 calves of both sexes; six received Cd (two groups), Zn, Cd, and Zn, and Cd and Se (two groups) and one group was a control. In Experiment II (21 bulls), three were given Cd, Cd, and Cu, and Cd and Zn, respectively, and one group was a control. For light microscopy, in Experiment I the highest amounts of silver granules were present in the samples of liver, small intestine, and vesicular gland of all the exposed groups; in Experiment II the most affected organs were liver, kidney, and small intestine. For electron microscopy, in Experiment I, after administration of Cd and Zn, the highest amounts of granules were seen in the cytoplasm of hepatocytes and cells of the proximal and distal renal tubules and the lowest amounts were found in glandular cells of the pancreas. Administration of Cd and Se resulted in the presence of large numbers of granules in the nuclei and nucleoli of spermatogonies. In Experiment II, ingestion of Cd and Zn in feed led to the appearance of highest amounts of granules in the nucleoli, nuclei, and cytoplasm of cells in testes, kidneys, and pancreas. Following Cd intake, the highest accumulation of granules was observed in the nucleoli of hepatocytes and cells of the proximal and distal renal tubules. Combined Cd and Cu produced the highest number of granules in cells of the proximal and distal renal tubules and in the nucleoli and nuclei of germinal epithelium.     

Human fetal ductal plate revisited. I. ductal plate expresses NCAM,KIT, MET,PDGFRA, and neuroendocrine antigens (NSE,chromogranin, synaptophysin,and CD56)

Background: The molecular mechanisms of ductal plate (DP) development and differentiation (DD) in human fetal livers (HFLs) are unclear. Materials and Methods: The author immunohistochemically investigated expressions of NCAM, KIT, KIT, PDGFRA, and neuroendocrine antigens in 32 HFLs. Results: The processes of human intrahepatic bile duct (IBD) DD could be categorized into four stages: DP, remodeling DP, remodeled DP, and mature IBD. NCAM was always expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. The biliary elements were positive for cytokeratin (CK)7, 8, 18, and 19. The hepatoblasts were positive for CK8 and CD18, but negative for CK7 and CK19; however, periportal hepatoblasts showed biliary‐type CKs (CK7 and CK19). NCAM was always expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. KIT was occasionally (12/32 cases) expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. NCAM expression was also seen in some hepatoblasts and hematopoietic cells and neurons. KIT was also expressed in some hepatoblasts, hematopoietic cells, and mast cells. MET and PDGFRA were strongly expressed in DP, remodeling DP, remodeled DP, and mature IBD. MET and PDGFRA were also strongly expressed in hepatoblasts and hematopoietic cells. MET and PDGFRA were not expressed in portal mesenchyme, portal veins, sinusoids, and hepatic veins. DP showed immunoreactive chromogranin, synaptophysin, neuron‐specific enolase (NSE), and CD56. Expressions of chromogranin and CD56 were infrequently seen in remodeling DP. No expressions of these four neuroendocrine antigens were seen in remodeled DP and mature IBD. The nerve fibers were consistently positive for chromogranin, synaptophysin, NSE, and CD56 in the portal mesenchyme in the stages of remodeling DP, remodeled DP, and mature IBDs. Conclusions: The data suggest that NCAM, KIT/stem cell factor‐signaling, NSE, hepatocyte growth factor/MET signaling, PDGFα/PDGFRA signaling, chromogranin, synaptophysin, and CD56 play important roles in DD of biliary cells of HFL. They also suggest that the DP cells having neuroendocrine molecules give rise to hepatic stem/progenitor cells. Microsc. Res. Tech. 77:814–824, 2014. © 2014 Wiley Periodicals, Inc.     

第十一届全国流体传动与控制学术会议综述

由中国机械工程学会流体传动与控制分会主办,上海交通大学承办的第十一届全国流体传动与控制学术会议于2020年10月31日-11月2日在上海顺利召开。本届会议的主题是“流体传动与控制+人工智能”。会议共收录内容涉及人工智能与数字化、元件与系统、密封、摩擦与润滑等6个方向的论文133篇,邀请杨华勇、焦宗夏等知名专家作大会报告9个,取得了良好效果。围绕会议主题、征文范围及大会报告与会议论文开展综述,并对相关统计数据进行了分析讨论,以供国内学者和工程技术人员研究参考,并为流体传动与控制学科发展及今后举办会议提供借鉴。     

智能机床发展现状与技术体系框架

智能机床成为机床装备发展的趋势。在介绍国内外智能机床的研究现状的基础上,分析目前智能机床技术研究的三个问题,提出智能机床的狭义和广义定义;给出智能机床的包括人计机的协同性、整体与局部的协调性、智能的恰当性与无止性、自学习及其能力持续提高性、自治与集中的统一性、结构的开放性和可扩展性、制造和加工的绿色性、智能的贯穿性八个智能技术特征;阐述包括以人为中心的人计机动态交互功能、三个基本功能——执行智能功能、准备智能功能、维护智能功能的智能功能特征,以及功能之间的相互关系;建立八个理论与技术的智能机床技术理论框架,包括人计机一体化融合理论与技术、多源信息的感知理论与技术、智能决策理论与技术、智能执行理论与技术、智能维护理论与技术、智能机床综合能力评价理论与技术、智能机床标准化技术、智能机床支撑技术等,形成了智能机床的技术体系框架,同时指出上述内容将随着技术的进步和应用的深入不断充实和丰富。     

Ion mobility mass spectrometry in the omics era: Challenges and opportunities for metabolomics and lipidomics

Researchers worldwide are taking advantage of novel, commercially available, technologies, such as ion mobility mass spectrometry (IM-MS), for metabolomics and lipidomics applications in a variety of fields including life, biomedical, and food sciences. IM-MS provides three main technical advantages over traditional LC-MS workflows. Firstly, in addition to mass, IM-MS allows collision cross-section values to be measured for metabolites and lipids, a physicochemical identifier related to the chemical shape of an analyte that increases the confidence of identification. Second, IM-MS increases peak capacity and the signal-to-noise, improving fingerprinting as well as quantification, and better defining the spatial localization of metabolites and lipids in biological and food samples. Third, IM-MS can be coupled with various fragmentation modes, adding new tools to improve structural characterization and molecular annotation. Here, we review the state-of-the-art in IM-MS technologies and approaches utilized to support metabolomics and lipidomics applications and we assess the challenges and opportunities in this growing field.     

A simplified wet friction clutch test apparatus

A small, economic, test rig to evaluate friction materials and fluids for wet clutch applications has been designed, built and commissioned. In this paper, the construction, operation and performance of the machine are described, and results are presented, for two sets of typical tests. The system is capable of recording data, and torque test track, coefficients of friction, and oil temperature rise, are given.     

The new concepts of measurement error theory

In current measurement theory, there are various logical and philosophical troubles, and the evaluation concepts of measurement error are various and inconsistent among different schools. This paper throws away the shackle of the current measurement theories and concepts, and re-discusses basic measurement concepts. By proving a new measurement error theory that any error is a bias and follows random distribution, this paper points out the misunderstanding of traditional measurement theory, subverts the traditional error category theory, gives out a new interpretation of measurement uncertainty concept, proposes abolishing the concept system of precision, trueness, and accuracy, and thereby achieves the united measurement concept system across all the disciplines, including geodesy, geomatics, metrology, instrumentation, and so on.     

生物轻质高强结构及其在吸能结构中的仿生应用

在长期进化过程中，自然界中的多种动物、植物形成了独特的轻质、高强结构，以此来抵抗外界的复杂冲击载荷，保护自身完整，满足生存需要。生物轻质高强结构的优越性，启发了科研和工程人员采用结构仿生学的方法来对管状和板状两大类吸能结构进行设计优化和改进。对竹子、茎秆/树干、羽轴、骨骼四类管状生物结构和甲虫鞘翅、贝壳、柚子皮、龟壳四类板状生物结构进行综述，阐述了分层、多孔、螺旋、中空等多种结构与轻质高强特性之间的关系。在此基础上，对比和分析了相应的结构元素在单胞管、多胞管、嵌套管、波纹管等管状吸能结构和蜂窝夹芯板、复合材料板、混合结构板等板状吸能机构中起到的作用。进一步对当前仿生吸能领域存在的结构复杂、质量大、缺乏普适性的机理和过渡“桥梁”等问题做出了分析；最后对仿生吸能技术的形式简单化、结构轻量化、理论通用化、“形神兼备”化发展趋势做出展望。     

Epibiotic microorganisms on copepods and other marine crustaceans

Although the occurrence of microbial (algal, protozoan, bacterial, and fungal) epibionts on marine crustaceans and other invertebrates has been documented repeatedly, the ecological context and significance of these relationships generally are not well understood. Recently, several studies have examined the population and community ecology of algal and protozoan epibionts on freshwater crustaceans. Even so, the study of microbial epibionts in aquatic environments is still in its infancy. In this review, we summarize associations of microalgae, protozoans, and bacteria with marine crustaceans, especially copepods. We note differences and commonalities across epibiont taxa, consider host-epibiont cycling of nutrients, generate hypotheses relevant to the ecology of the host and the epibiont, and suggest future research opportunities. Microsc. Res. Tech. 37:116–135, 1997. © 1997 Wiley-Liss, Inc.     

Assessment of PM-EDM cycle factors influence on machining responses and surface properties of biomaterials: A comprehensive review

Powder mixed-electro discharge machining (PM-EDM) is recently evolving machining technique which can simultaneously remove and modify the machined surface through thermo-electrical process. It is a modified form of EDM in which the conductive powder elements are added in the dielectric liquid to enhance machined surface characteristics and machining responses. The commonly used biomaterials such as 316L stainless steel, Ti-based alloy, Ni–Ti, Mg alloy, and Co–Mo–Cr alloy have excellent mechanical characteristics while the biofunction of these materials are not in satisfactory level. Due to higher hardness, brittleness, and heat resistant natures of the biomaterials, it is very challenging to machine them with conventional machining. Both the system efficiency and modified surface properties depend on the associated electrical and non-electrical factors of PM-EDM cycle. This review focuses on the influence of process factors such as current, pulse duration, tool-polarity, duty cycle, potential voltage, types of liquid, and added powder concentration on performance outputs including material removal and tool wear rate, coating thickness, coarseness, microhardness, coating adhesion bonding, biocompatibility, and resistant to corrosion. This study also discusses influence of various powders on machining and modified surface characteristics of biomaterials. The future research scopes and challenges of PM-EDM process are included in this study thoroughly.