HGA—700型石墨炉升温原理和石墨管断报警电路剖析

1 石墨炉升温原理 一个完整的石墨炉电源,必须包括一个由时间程序控制的代表石墨炉设置温度的模拟信号源。模拟信号变化的时间间隔相对于各个升温阶段,而模拟电压信号可以用来控制施加于石墨炉的电压、电流或功率。其变化可以是脉冲的或是连续的,即相应于脉冲升温方式和斜坡升温方式。现代的石墨炉电源这一部分通常由微机实现,控制一个数模转换器产生模拟信号,即给出不同升温阶段对     

石墨防锈剂新工艺

本文简要地介绍了石墨防锈处理可锻铸铁零部件非机加面的新工艺。该工艺简单,操作方便,效率高,涂层均匀光滑,附着力强,外观质量和防锈能力明显提高,不污染环境,经济效益显著     

浸玻璃碳石墨材料的开发与应用

介绍了浸玻璃碳石墨材料的发展现状、所具有的优异特性、制造工艺以及应用实例等。     

石墨探针／石墨炉原子吸收光谱测定人发中痕量银

本文报道了石墨探针实现等温原子技术测量痕量银的方法，并成功地应用于人发中痕量银的测定，结果满意。     

金刚石工具制造用热压模石墨材料性能

石墨以其良好的性能和一定的机械强度及优良的加工性能等特点而成为金刚石工具制造中为数不多的热压模材料中的首选材料     

膨胀石墨和柔性石墨的应用前景及发展趋势

本文着重介绍了膨胀石墨和柔性石墨在密封、环保、医药、催化、润滑等方面的应用及存在的问题,并提出了将来的研究发展方向。     

The photoreceptive cells of the pineal gland in adult zebrafish (Danio rerio)

The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail. Therefore, this study was undertaken to analyze the structure and ultrastructure, as well as the immunohistochemical profile of the zebrafish pineal gland with particular reference to the pinealocytes. Here, we demonstrated, using RT-PCR, immunohistochemistry and transmission electron microscopy, the expression of the mRNA for rhodopsin in the pineal gland of zebrafish, as well as its cellular localization exclusively in the pinealocytes of adult zebrafish. Moreover, the ultrastructural observations demonstrated that the pinealocytes were constituted by an outer segment with numerous lamellar membranes, an inner segment with many mitochondria, and a basal pole with the synapses. Our results taken together demonstrated a central role of zebrafish pinealocytes in the control of pineal gland functions.     

填料密封阻塞下气体螺旋密封的数值模拟研究

针对填料密封阻塞下的气体螺旋密封泄漏问题,利用多孔介质概念对填料密封阻塞下的气体螺旋密封做了计算流体力学(CFD)数值模拟,用多孔介质概念来类比填料密封泄漏的机理,建立了相应的计算模型,并分析了该方法的可行性。数值模拟的计算结果表明,在给定的泄漏量条件下,填料密封渗透率分别随着螺旋密封的螺旋角,螺旋结构与壁面间隙及螺旋结构本身的槽深增大而减小,成反比例关系。当螺旋结构的螺旋角,螺旋结构与壁面间隙及螺旋结构本身槽深增大到一定范围时,螺旋密封的效果大大降低,这时填料密封在整个密封装置中起主要的密封作用。该研究结果为填料密封作用下的螺旋密封设计提供了一定的理论基础。     

Segmentation of intestinal gland images with iterative region growing

A region growing algorithm for segmentation of human intestinal gland images is presented. The initial seeding regions are identified based on the large vacant regions (lumen) inside the intestinal glands by fitting with a very large moving window. The seeding regions are then expanded by repetitive application of a morphological dilate operation with a much smaller round window structure set. False gland regions (nongland regions initially misclassified as gland regions) are removed based on either their excessive ages of active growth or inadequate thickness of dams formed by the strings of goblet cell nuclei sitting immediately outside the grown regions. The goblet cell nuclei are then identified and retained in the image. The gland contours are detected by applying a large moving round window fitting to the enormous empty exterior of the goblet cell nucleus chains in the image. The assumptions based on real intestinal gland images include the closed chain structured goblet cell nuclei that sit side-by-side with only small gaps between the neighbouring nuclei and that the lumens enclosed by the goblet cell nucleus chains are most vacant with only occasional run-away nuclei. The method performs well for most normal and abnormal intestinal gland images although it is less applicable to cancer cases. The experimental results show that the segmentations of the real microscopic intestinal gland images are satisfactorily accurate based on the visual evaluations.     

Confocal laser scanning microscopic analysis of ectopic sublingual gland‐like tissue inside the hamster submandibular gland

Based on its histochemical properties, the secretory portion of the hamster submandibular gland has been classified as seromucous cells. The presence of endogenous peroxidase (PO) reaction was shown in the nuclear envelope, cisternae of endoplasmic reticulum and Golgi apparatus. The 3,3′‐diaminobenzidene, tetrahydrochloride (DAB) method revealed bipartite secretory granules containing a PO‐positive dense core surrounded by a less dense halo in these cells. In the present investigation, serous and mucous‐like cells were found in resin‐embedded semi‐thin sections of the DAB‐reacted hamster submandibular gland. These sections were already on glass slides for routine light microscopic observations, therefore electron microscopic analysis could be unrealizable. We then used reflectance‐mode confocal laser scanning microscopy to visualize additional sites of PO activity as detected in these sections. Using this approach, we found mucous cells with PO activity‐negative secretory granules and seromucous cells with PO activity‐positive spot‐like secretory granules of the regular sublingual gland most frequently adjacent to the serous cells with typical electron‐dense secretory granules. These cells clearly differ from the seromucous cells with bipartite secretory granules and the granular duct cells with typical electron‐dense secretory granules of the hamster submandibular gland. Additionally, secretory endpieces of the ectopic sublingual gland‐like tissue empty into the duct of the hamster submandibular gland lobule. Thus, our findings suggest that a mass of sublingual gland tissue extends into the hamster submandibular gland during its development, and PO may be synthesized and secreted into the same duct. Microsc. Res. Tech. 76:1284–1291, 2013. © 2013 Wiley Periodicals, Inc.     

The morphology of the pineal gland of the yellow‐toothed cavy (Galea Spixii Wagler, 1831) and red‐rumped agouti (Dasyprocta leporina linnaeus, 1758)

The pineal gland is an endocrine gland found in all mammals. This article describes the morphology of this important gland in two species of Caviideae, namely the yellow‐toothed cavy and the red‐rumped agouti. Ten adult animals of the two species used in current analysis were retrieved from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) and euthanized. The glands were removed and photographed in situ and ex situ. They were fixed in a paraformaldehyde solution 4% or glutaraldehyde 2.5% solution and submitted to routine histological techniques respectively for light and scanning electron microscopy. Macroscopically, the pineal gland with its elongated structure may be found between the cerebral hemispheres facing the rostral colliculi. Microscopically, pinealocytes and some glia cells were predominant. Contrastingly, to the cavy's pineal gland, a capsule covered the organ in the agouti, with the emission of incomplete septa to the interior, which divided it into two lobules. Light and scanning electron microscopes failed to show calcareous concretions in the pineal gland. Based on the topography of the cavy's and agouti's pineal gland, it may be classified as supra‐callosum and ABC type. Microsc. Res. Tech. 78:660–666, 2015. © 2015 Wiley Periodicals, Inc.     

防尘盖轴承压盖模具改进

通过对防尘盖轴承压盖后外径变形原因的分析后发现,模具结构是造成外径变形的原因,故对该模具进行了改进设计,将压盖工序对产品外径变形影响降至最低限度,达到了降低废品率的目的。     

缸盖垫片厚度非接触测量系统的研究

缸盖垫片是冰箱压缩机的一个密封件,对其厚度尺寸的测量和分选是装配前的一道关键工序。由于缸盖垫片质软轻薄,若采用接触式测量,则垫片易受测力的影响,测量精度无法保证。为此采用一种集光电测量技术、单片机应用技术于一体的非接触式测量系统对缸盖垫片的厚度进行自动检测和分选。本文介绍了激光扫描测量原理和单片机控制的测量系统及其软硬件的设计。以单片机为核心开发的该控制系统能对缸盖垫片的厚度进行自动测量,从而保证了缸盖垫片厚度的测量精度。     

Secretory profile of metapleural gland cells of the leaf-cutting ant Acromyrmex coronatus (Formicidae: Attini)

Ants present a pair of metapleural glands located at the posterolateral end of the thorax. Because of its importance in the social organization of ants, the present study was aimed at describing the morphophysiology of this gland in three worker castes of Acromyrmex coronatus, focused on secretory activity using histological and histochemical techniques. Our findings revealed that the secretory and the storage portions of this gland are connected by extracytoplasmic portion of canaliculi that drain the secretion from each secretory cell to the collecting chamber. This secretion contains glycoproteins. In minor workers, the secretion contains higher levels of polysaccharides when compared to that of major workers, supporting the role of the metapleural gland in the maintenance of the fungus garden. The nucleus as well as cytoplasm of secretory cells were strongly positive for RNA indicating that these cells are active in the synthesis of proteins and lipids, compounds found in the final secretion. The variant of the CEC revealed that the secretory activity of the entire gland is synchronous, as all cells exhibit the result.     

Sensilla and secretory glands in the antennae of a primitive ant: Dinoponera lucida (Formicidae: Ponerinae)

Morphology of the antennae of the female workers of the ponerine ant Dinoponera lucida was examined by light and scanning electron microscopy. In several antennomers, we found secretory gland cells of class I and III. Class III gland cells release their secretion through single pores in the antennal surface, whereas class I secretory cells are seen as tall epidermal cells close to the cuticle. Both gland types have weak reaction for total proteins and neutral polysaccharides. Six distinct sensilla types were observed: trichodea, chaetica, campaniform, basiconica, placodea, and coeloconica. The possible sensory functions of these sensilla and the gland functions are discussed.