喷射电沉积快速成形的定域性实验研究

介绍了喷射电沉积快速成形技术的基本原理，分析了金属零件成形过程中，定域性对零件成形精度的重要性，并对影响定域性的因素进行了基础实验研究。结果表明：喷嘴口径、喷嘴与阴极间的距离对定域性有密切关系，喷嘴口径小、喷嘴距离小，则定域性好，尺寸精度高；阴极电流密度和喷嘴扫描速度对定域性亦有影响，阴极电流密度低、喷嘴扫描速度快，则金属沉积斑尺寸小，定域性好。     

顶空气相色谱法快速测定氯化石蜡-70中四氯化碳含量

介绍了采用顶空气相色谱法对氯化石蜡-70中四氯化碳的含量进行测定，该方法具有前处理简单、干扰因素小，对色谱系统污染小且快速、准确、分离完全等特点。     

应用单刃外铰刀对小直径深孔进行高效、精密加工

小直径深孔的精密加工目前存在的主要问题是生产率较低。本文通过对单刃铰刀加工小直径深孔的试验研究，认为单刃铰刀完全适用于小直径深孔的高效、精密加工，并且，在机床转速允许的条件下，切削速度有进一步提高的可能。     

应用单刃铰刀对小直径深孔进行高效,精密加工

小直径深孔的精密加工目前存在的主要问题是生产率较低。本文通过对单刃铰刀加工小直径深孔的试验研究，认为单刃铰刀完全适用于小直径深孔的高效、精密加工，并且，在机床转速允许的条件下，切削速度有进一步提高的可能。     

基于改进注意力W-Net的工业烟尘图像分割

针对小目标烟尘尺寸小、边缘稀薄和U-Net在提取小目标烟尘特征效果不佳等原因导致的烟尘漏检、误检和分割精度低等问题，提出一种基于改进注意力W-Net(IAW-Net)的烟尘图像分割网络。采用注意力机制将U-Net扩展为W-Net,在W-Net的基础上引入改进的注意力机制，增强了小目标烟尘的特征；针对小目标烟尘特点对焦点损失进行改进，增加了小目标烟尘的分割比重。实验结果表明，IAW-Net能够在不影响大目标烟尘分割的基础上更加关注小目标烟尘的分割效果，从而提升了烟尘图像的整体分割能力，相比现有语义分割网络具有更好的分割效果。     

BIOSMEDI生物滤池处理微污染源水

本文对BIOSMEDI生物预处理的结构及运行原理进行简要介绍，同时通过对不同生物预处理形式和原水预处理试验比较表明，BIOSMEDI生物滤池预处理具有处理效率高、阻力损失小、反冲洗耗水、耗气量小等优点。     

小弯曲半径弯管的对挤成形

锅炉的弯管大都在弯管机上采用冷弯或热弯成形。管件的弯曲半径越小，其变形程度越大。在管件弯曲变形的同时，还会伴随着截面畸变。由于弯头的极限变形程度和截面畸变的限制，弯头最小弯曲半径必须大于某一极限数值，一般相对弯曲半径大于25。即使采用热弯，并辅以各种防止截面畸变措施，其最小相对弯曲半径一般也不能小于1．5。要想获得更小的弯曲半径的弯头，采用单纯弯曲是不可能实现的。近年来，随着锅炉制造工艺的发展，研究开发了一种小弯曲半径弯头成形新工艺——小弯曲半径弯头对挤成形。一、对挤成形工艺小弯曲半径弯头对挤工艺为…     

C2型小角度检查仪升级改造研究

C2型小角度检查仪是一种使用光学计来复现离散微小角度的测量仪器。仪器使用已近40年，存在整体精度下降、光学系统老化等问题，且无法检定框式水平仪和条式水平仪。通过重新自行设计加工仪器主体工作台，运用光电传感器技术和计算机控制技术对仪器进行升级改造研究，实现自动产生标准角度，配置配套标准器具，建立小角度检查仪标准装置。通过升级改造研究后的小角度检查仪，扩展不确定度为0.3″，重复性、稳定性、试验比对结果均满足国防科技工业二等小角度标准装置考核要求，达到国内先进水平，提升了公司小角度的量传能力，减小人为误差。     

小模数塑料齿轮静态强度试验台研制与实验研究

为获取小模数塑料齿轮的静态强度，研发了小模数塑料齿轮静态强度试验台，可以精准测量出不同模数、转速、材料的塑料齿轮的静态强度。重点介绍了试验台的工作原理、构成和工装零部件的设计。试验台由机械系统、电控系统和测量软件组成，主要采用卧式结构，结构紧凑，占用空间小，工装夹具设计简单，便于测量。进行了静态强度的测试试验，测试了不同材料的静态强度。该试验台的研发，解决了小模数齿轮静态强度测试不准、测试装夹困难的问题。研究对塑料齿轮设计有一定的理论价值与实际应用价值。     

薄壁杆件结构力学计算桥类起重机小车架

应用薄壁杆件结构力学方法，结合ＥＯＴＣ５型桥式起重机的典型情况，对小车架的强度、刚度和构件间的约束进行了分析，简要阐述了薄壁杆件结构力学的应用特点，通过理论分析与实测结果的比较，指出了现行常规小车架设计计算的不足，提出了精确设计小车架的建议。     

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.     

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。     

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.     

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.