涂膜附着力测试仪校准方法的研究

涂膜附着力测试仪在水运工程等领域应用广泛,但是国内一直未发布与其专门相关的计量技术规范,缺乏完整的涂膜附着力测试仪计量测试方法。该文介绍了涂膜附着力测试仪的工作原理,提出了涂膜附着力测试仪的具体校准方法,选取样机进行了试验测量,对其测量不确定度进行分析,论证了校准方法的可行性,为涂膜附着力测试仪计量技术规范的编制提供了支撑。     

排除感应电影响的回路电阻测试仪改造

在感应电较为强烈的工作现场试验时,感应电加在回路电阻测试仪两端,会影响测试仪正常工作,导致测量结果不准确,严重时可能损坏回路电阻测试仪。基于上述情况,对回路电阻测试仪进行了相关的研究,通过在回路电阻测试仪上加装排除感应电干扰功能,很大程度上解决了由于感应电所造成的无法正常测量回路电阻的问题。     

导弹地面电缆绝缘电阻测试仪的不确定度分析

为了对所设计的导弹地面电缆自动化绝缘电阻测试仪的测量结果进行科学评价,简单介绍了绝缘电阻测试仪的硬件设计,详细介绍了采样电路的设计,分析了影响所设计的绝缘电阻测试仪不确定度的各个因素,以及每个因素给仪器测量不确定度带来的影响,列出了所设计的绝缘电阻测试仪的标准不确定度一览表,为科学评价所设计的绝缘电阻测试仪的性能提供了依据.     

网络测试仪的研制与分析

主要对网络测试仪的技术背景及产品概念进行了分析,并在此基础上提出了网络测试仪硬件结构和软件功能逻辑结构的设计方案。     

浅谈安全性能综合测试仪的校准方法

本文介绍了安全性能综合测试仪的基本工作原理．并对安全性能综合测试仪的现场校准工作进行了阐述,对其校准工作中遇到的问题提出了几点思考。     

氢气环境材料力学性能测试仪研发概述

氢损伤是金属由于气体作用而造成破坏的重要形式之一,相应的材料性能测试仪则是其不可或缺的研究工具。对用于氢气环境下材料机械性能测试的仪器设备现状进行了概述,以期为进一步的研究提供有益参考。首先,通过对主要测试仪公司的调研,概述了市场现有的相关测试仪产品情况;其次,通过学术文献调研,概述了氢气环境测试仪的研究情况。调研结果表明:测试仪公司没有用于氢气环境材料性能测量的测试仪产品;研究机构方面,氢气环境测试仪已有较多研究,但尚未有集高温、高压氢气环境以及复杂载荷加载能力于一体的测试仪器。这样的测试仪目前正是石化、电力等行业临氢设备安全性能测试、失效机理分析、材料性能数据库建立乃至新材料研发所急需的,因此亟需进行相应测试仪的研发。     

便携式光伏方阵测试仪的研制

全面阐述了最近研制的便携式光伏方阵测试仪.并对测试仪中的创新部分进行了详细的分析.该仪器 在硬件方面使用了电容式电子负载和高速同步采样电路;软件方面使用了操作系统和文件系统.最后通过实验结果可知该测试仪具有良好的精度和可重复性,符合了光伏组件测试的标准.     

CsI探测器余辉性能测试仪关键技术研究与实现

为检测Cs I(Tl)探测器的余辉性能,帮助探测器进行分档,论文通过对余辉测试仪设计过程中的电动缸选型计算、射线屏蔽、电磁兼容设计等关键问题进行分析,自主研发了一台Cs I探测器余辉测试仪。该测试仪快门关断时间≦3ms;可测余辉值的时间范围:5ms~500ms。并能对采集数据进行分析,得到探测器晶体各像素的余辉和平均余辉,及其变化曲线。余辉测试仪的检测结果将为安检整机提供具有数据信息的系列探测板,促进其图像质量更上一层楼。     

基于人机工程学的智能酒精测试仪设计研究

针对当前酒精测试仪的使用还存在体积大、测试识别不方便等诸多问题,引用人机工程学原理和人体测量尺寸数据进行了深化研究,提出了更便携的、智能化的酒精测试仪改良设计方案。立足手的解剖学特征和立姿静动态尺寸,对酒精测试仪进行了完善,能够更加贴合人手握的舒适感受;在满足有效监测饮酒驾驶的同时,充分考虑了酒精测试仪的交互方式,对手柄、连接结构及各个部件进行了材质选择、色彩搭配等具体设计工作。利用APP客户端,实现了产品的实时数据交接。研究结果表明,该产品的设计创新为提高该类产品的使用舒适性提供了思路。     

变压器直流电阻测试仪的改造及应用

变压器需要定期进行直流电阻测试,而原有变压器直流电阻测试仪是对变压器A、B、C三相的直流电阻分别进行测试的,工作效率低。现提出两点改进方案,对变压器直流电阻测试仪增加三相同时测量的功能以及自动计算三相平衡率的功能。实践证明,该改造方案有效提高了测试仪的性能,且极大地提高了工作效率。     

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.     

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.     

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.     

Taxonomic significance of caryopsis in subfamily Panicoideae (Poaceae) using scanning electron microscopy and light microscopy

In recent study, 13 taxa of subfamily Panicoideae were investigated for morphological characterization of caryopsis. Light microscope (LM) and scanning electron microscope (SEM) were utilized to study macro‐ and micro‐morphological caryopsis features respectively. Caryopsis size in studied taxa was recorded as 1.5–10 mm long and 1–4 mm wide. Caryopsis color was brown, green, yellow, and whitish‐brown. Caryopsis shape studied was obovate, elliptic, linear oblate, and round shallowly obtriangular. Hilum position is grooved and depressed. Caryopsis compression type was lateral and dorsiventral. Major variations among studied taxa were observed in terms of caryopsis surface pattern and epicuticular projection types. Six types of caryopsis surface pattern were observed viz. scabrate, rugose, striate, reticulate, papillate, and scabridulous. Structures such as silica cells, bulges, spines, prickles, granules, and bicellular microhair were studied as epicuticular projections. Major variations were observed among Cenchrus pennisetiformis and Cenchrus ciliaris as both has entirely two different types of surface patterns and epicuticular projections. Anticlinal wall thickness and pattern as well as periclinal wall texture and level were investigated. The present research work emphasized on caryopsis characterization of subfamily Panicoideae and it is recommended to establish phylogeny within subfamily Panicoideae and with other subfamilies of Poaceae.     

城市生活污水中阿片类、苯丙胺类以及苯二氮卓类滥用物质的高分辨质谱筛选及确证

本研究采用固相萃取对城市生活污水样品进行前处理,超高效液相色谱-串联高分辨质谱法筛选及确证污水中阿片类、苯丙胺类和苯二氮卓类等36种滥用物质,并将其应用于实际污水样品。结果表明,该方法的专属性强,36种滥用物质的检出限范围为5~20 ng/L。在12个污水样品中共检出吗啡、可待因、哌替啶、曲马多4种阿片类滥用物质,甲基苯丙胺1种苯丙胺类滥用物质以及地西泮、去甲西泮、艾司唑仑、阿普唑仑4种苯二氮卓类滥用物质。城市生活污水中存在多种滥用物质,区域流行性不同,利用本方法可进行快速、准确地筛选与确认。     

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.     

Review on microbial metabolomics of probiotics and pathogens: Methodologies and applications

In recent years, microbial metabolomics, a new field that has attracted wide attention, provides a map of metabolic pathways and clarifies the interaction mechanism between microorganisms and hosts. Many microorganisms are found in the human intestine, oral cavity, vagina, etc. Probiotics could maintain the good health of the host, while pathogens and an imbalance of bacterial flora lead to a series of diseases of the body and mind. Metabolomics is a science for qualitative and quantitative analysis of all metabolites in an organism or biological system, which could provide key information to understand the related metabolic pathways and associated changes. This approach analyzes the final products of cellular regulatory processes, the level of which can be regarded as the ultimate response of the biological system to genetic or environmental changes. Microbial metabolomics has been widely used in different research fields, such as microbial phenotypic classification, mutant screening, metabolic pathways, microbial metabolic engineering, fermentation engineering monitoring and optimization, microbial environmental pollution, and so on. However, there are only a few reviews on microbial metabolomics of probiotics and pathogens. This review summarizes the main methodologies, including sample preparation, identification of metabolites, data processing, and analysis. Recent applications in microbial metabolomics of probiotics and pathogens are also described. This paper first summarized the research progress and application of microbial metabolomics from two aspects: probiotics and pathogenic bacteria. Probiotics and pathogenic bacteria do not exist independently most of the time; hence, these were reviewed in the research field of coexistence of probiotics and pathogenic bacteria, which was subdivided into important microbial research fields closely related to human health, including the human gut, oral cavity, food, and nutrition-related microorganisms. Then, the main problems and trends associated with microbial metabolomics are discussed.     

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

Fiber-reinforced composites have become the preferred material in the fields of aviation and aerospace because of their high-strength performance in unit weight. The composite components are manufactured by near net-shape and only require finishing operations to achieve final dimensional and assembly tolerances. Milling and grinding arise as the preferred choices because of their precision processing. Nevertheless, given their laminated, anisotropic, and heterogeneous nature, these materials are considered difficult-to-machine. As undesirable results and challenging breakthroughs, the surface damage and integrity of these materials is a research hotspot with important engineering significance. This review summarizes an up-to-date progress of the damage formation mechanisms and suppression strategies in milling and grinding for the fiber-reinforced composites reported in the literature. First, the formation mechanisms of milling damage, including delamination, burr, and tear, are analyzed. Second, the grinding mechanisms, covering material removal mechanism, thermal mechanical behavior, surface integrity, and damage, are discussed. Third, suppression strategies are reviewed systematically from the aspects of advanced cutting tools and technologies, including ultrasonic vibration-assisted machining, cryogenic cooling, minimum quantity lubrication (MQL), and tool optimization design. Ultrasonic vibration shows the greatest advantage of restraining machining force, which can be reduced by approximately 60% compared with conventional machining. Cryogenic cooling is the most effective method to reduce temperature with a maximum reduction of approximately 60%. MQL shows its advantages in terms of reducing friction coefficient, force, temperature, and tool wear. Finally, research gaps and future exploration directions are prospected, giving researchers opportunity to deepen specific aspects and explore new area for achieving high precision surface machining of fiber-reinforced composites.     

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.