大鲵皮肤的扫描电镜观察

皮肤具有多种功能,能保护机体免受损伤,陆生动物靠皮肤避免水分蒸发,且能吸收养分、排除废物,具有呼吸功能;在高等脊椎动物,皮肤有调节体温、维持水分的作用。而大鲵(Andrias davidianus)是我国特有的大型珍稀有尾两栖动物,在研究动物发展、进化上具有重要科学价值。大鲵皮肤表面分布有不规则大小不匀的丘状突起,且皮肤柔软而裸露,富含腺体,经常保持湿润,这与其利用皮肤呼吸有密切关系。1.扫描电镜下大鲵皮肤表面结构:其外观凸凹不平,表皮最外部分由扁平上皮细胞组成,在蜕皮的皮肤表面扁平细胞特别明显(图1),有的扁平细胞中间有较大的细胞核(图2),这些细胞大小有差异。在皮肤表面可看     

人体染色体纤维结构的扫描电镜观察

光镜G带染色体按Seabright(1971)法制作后,选出分裂相好的染色体,标志和照相。接着按扫描电镜常规法处理,在S—570扫描电镜观察照相。要做好佯品,胰酶处理是关键环节。结果表明所有染色体都是由纤维丝、颗粒结构和环状结构组成的。纤维丝称染色质纤或染色质丝,直径有150A、300A、900A等,大多是200～300A(图1↑)。染色质纤维是由100A的核小体串珠链在H_1组蛋白的诱导下形成超螺旋,并与非组蛋白装配而成。染色质纤维的长度有7.6厘米(J.J.Yunis.1977)。在着丝点和凹陷带区一般呈纵向排列(图1↑)。在隆起带区和随体呈网状或无规则排列。在染色体周边呈放射状排列。     

植物气孔复合体的扫描电镜观察

本文对16种有代表性的双子叶及单子叶植物叶片的远轴面气孔复合体作了扫描电镜(SEM)观察。通过精细的制样及适时的观察照像,以其清晰而富有立体感的图像揭示出植物气孔复合体的三维结构和基本类型及其在不同生活环境中气孔复合体的多姿形态。本文将对植物形态学、植物生理学及植物系统发育与分类的研究有一定参考价值。     

哈尔滨常见植物花粉的扫描电镜观察

哈尔滨常见植物花粉的扫描电镜观察＊张大维张贵一刘保东（哈尔滨师范大学生物系，哈尔滨１５００８０）呼吸道过敏性疾病，在某些地区和国家患病率较高，并引起一些并发症。植物的花粉是空气中主要的吸入性过敏原物质。人体吸入后易患花粉症，该症属于环境性疾病，严格说...     

重组合异种骨的扫描电镜观察

骨形成蛋白(Bone morphogenetic protein,BMP)及其复合载体的研究是近年来国内外开展的新课题。作为骨缺损修复材料,BMP必须结合适宜的支架,一则起到机械支持作用,二则减弱BMP的吸收释放以利于活性发挥。作者在异种骨移植的研究中将小牛骨松质部分化学处理以消除其抗原性,同时从小牛骨皮质部分提取BMP成份,然后将两者再结合制成重组合异种骨,对这种植骨材料的结构特征进行了扫描电子显微镜观察和生物学活性分析。     

湿木材的环境扫描电镜观察

本文用环境扫描电镜(environmental scanning electron microscopy，ESEM)对饱水杉木切片进行了观察。结果表明：1)ESEM可用于观察未经任何处理的湿木材细胞；2)通过在不同条件下对样品的观察，得知样品温度5℃、样品室气压732Pa(样品周围的相对湿度85％)是比较合适的环境条件，拍摄得到的照片最清晰；3)环境方式下对样品的观察和对图像的记录等操作应尽快完成，以减少样品内水分的蒸发而使样品的变形降至最低。     

铀矿工头发的扫描电镜观察

长期在铀矿井下作业的工人 ,可以通过各种途径吸入氡及其短寿命子体 ,使体内存贮着一定量的放射性核素 ,形成一种内照射源 ,从而影响作业人员的身体健康。氡及其子体是导致矿工肺癌的主要原因 ,并且肺癌危险随氡子体累积暴露量的增加而增高 ,这已为许多调查报告所证实 [1— 3]。氡子体可以穿过毛表皮在毛发内受到角蛋白中二硫键的化学束缚而沉积下来 ,引起内照射剂量。本研究的目的是观察矿工头发表层毛小皮细胞超微结构的变化 ,以期探讨氡子体累积暴露量与头发表层细胞改变效应关系。材料和方法样品取自湖南和江西两矿共 2 8名矿工的头发 ,…     

大豆根瘤的扫描电镜观察

大豆与大豆根瘤处于一个共生的体系,大豆为大豆根瘤的生长提供适宜的微观环境,而大豆根瘤则为大豆植株的发育提供必要的养分.豆科植物的生物固氮能力是通过根瘤菌的侵染完成的.大豆根被根瘤菌侵染后,形成共生体根瘤,根瘤菌通过生物固氮作用将空气中的氮转化为氨供给大豆利用.本实验以东农46为研究对象,利用扫描电子显微镜技术,对大豆发育过程中根瘤、根瘤菌和淀粉粒的结构特征、形态变化进行超微结构观察.结果表明,大豆发育过程中根瘤的发育可分为三个时期,即:根瘤菌的侵入和感染;根瘤的形成和发育;根瘤及根瘤菌退化.各时期的根瘤菌经历了形态及数量发育的变化,由初期数量较少、形态不规则,到数量大幅度增加充满侵染细胞,最终随着侵染细胞开始衰亡其内部的根瘤菌逐渐减少至全部消失.     

田菁种子亚显微结构的扫描电镜观察

田菁(Sesbania canabina)为豆科田菁属(Sesbania Scop)植物。对于石油工业及轻工业用途甚广的田菁胶(半乳甘露聚糖类型的植物胶),就是从田菁种子中提取的。豆科植物种子通常有革质的种皮和大而肥厚的子叶,一般无胚乳。而田菁种子不但有胚乳且很发达。田菁种子是由种皮、胚乳、子叶等组成(图2)。种皮似革质,约占种子重量的20％,是由柱状的栅栏细胞形成的表皮层和由近园形厚壁细胞形成的表皮下层组成(图3、4)。成熟的田菁种子种皮上有一层蜡质,种皮的栅栏细胞壁加厚形成了坚固致密的保护层。如果种子过分成熟,种皮细胞干缩则会增加种子的硬实率,甚至种子会失去透水性从而影     

正常人咽鼓管粘膜的扫描电镜观察

正常人咽鼓管粘膜的扫描电镜观察孙建和杨伟炎姜泗长朱光明＊张曙光＊侯宁＊（解放军总医院耳鼻咽喉科，＊电镜室，北京１００８５３）咽鼓管连结中耳腔和鼻咽部，是气体由鼻咽到中耳的通路，由此维持中耳的气压平衡和声音的正常传导。纤毛细胞纤毛的主动运转机制和杯状细...     

原生动物扫描电镜样品制备方法的探讨

以腹毛目纤毛虫棘尾虫、尖毛虫和游仆虫,膜口目纤毛虫草履虫以及腰鞭目鞭毛目角藻为材料,对原生动物扫描电镜样品制备方法作了探讨,提出了样品制备过程中取材固定、脱水、干燥后原生动物在样品台上的定位等值得注意的问题,取得成功的关键及一些体会。     

Scanning Kelvin Probe Microscopy on Bulk Heterojunction Polymer Blends

Here, correlated AFM and scanning Kelvin probe microscopy measurements with sub‐100 nm resolution on the phase‐separated active layer of polymer‐fullerene (MDMO‐PPV:PCBM) bulk heterojunction solar cells in the dark and under illumination are described. Using numerical modeling a fully quantitative explanation for the contrast and shifts of the surface potential in dark and light is provided. Under illumination an excess of photogenerated electrons is present in both the donor and acceptor phases. From the time evolution of the surface potential after switching off the light the contributions of free and trapped electrons can be identified. Based on these measurements the relative 3D energy level shifts of the sample are calculated. Moreover, by comparing devices with fine and coarse phase separation, it is found that the inferior performance of the latter devices is, at least partially, due to poor electron transport.     

免疫扫描电镜样品的简单制备方法

本文介绍一种用免疫扫描电镜技术研究病毒感染的细胞表面的简易制样方法。适当控制镀金膜的厚度(约5nm厚),即可观察到直径仅20nm胶体金标记物的二次电子图象。与近年来发展起来的背散射成象法比较,细胞表面甚至病毒粒子的形貌更为清晰。     

Exact 3D simulation of Scanning Electron Microscopy images of semiconductor devices in the presence of electric and magnetic fields

Simulations of Scanning Electron Microscopy images of semiconductor devices in the presence of electric fields are usually too simplistic, since they just rely on approximated solutions of the Poisson equation. In this paper, the 3D Poisson equation is solved in a TCAD environment, which accounts for realistic boundary conditions, as well as for complex physical effects like the formation of space charge regions in semiconductors and the polarization of dielectrics. The calculated solution is then passed to a Monte Carlo code that implements a new electron tracking engine optimized for speed, stability, and accuracy. After introducing the new tracking engine, three simulation examples are presented dealing with the presence of an extraction field, self-charging of the irradiated sample, and potential contrast in a biased silicon junction.     

Nanomanipulation of Ligand‐Stabilized Au55 Clusters by Means of Scanning Tunneling Microscopy

We have investigated ligand‐stabilized Au₅₅ clusters by means of scanning tunneling microscopy (STM) at room temperature on highly oriented pyrolytic graphite (HOPG) and other substrates. Single clusters or groups of several clusters were transferred between sample and STM tip using conventional voltage pulses. With a new variant of voltage pulses called “field‐emission pulses”, cluster shells were partly destroyed by heating with the field‐emission current, resulting in a “hardening” of the cluster layer. HOPG substrate surfaces with most of the clusters removed exhibit “pearl chains” of clusters attached to step edges.     

Conventional Electron Microscopy and Electron Holography of Organic Solar Cells

Organic solar cells are a promising route towards large‐area and low‐price photovoltaic systems. The devices are composed of at least two layers: the hole‐transport layer and the electron‐transport layer. The light absorption can occur in one or both layers. At the interface of the layers the excitons are separated into charge carriers, and every layer deals with one type of carrier. Higher efficiencies of the separation process can be obtained by using a mixed layer containing both materials to obtain a very high interface area. Although the structure of the mixed layers used plays a crucial role for the device performance, until now the morphologies have not been elucidated. In order to correlate physical and optical findings with structure and morphology for the materials in question, electron microscopy experiments were performed on the single components as well as on the layer systems. The conventional electron microscope is a poor phase microscope. As consequence, weak‐phase objects like organic molecules have to be stained or imaged under strong defocus to produce an observable contrast. Artifacts caused by chemical staining and the appearance of Fresnel diffraction using the defocus technique represent the main problems of conventional microscopy. These artifacts can be avoided using electron holography. Holograms of ultrathin sections of thin layers composed of organic dye molecules were recorded. Subsequently, the phase images were reconstructed. In this manner, we succeeded in obtaining high‐contrast electron micrographs without applying staining or defocus. In addition, holograms of crystalline C₆₀ and zinc phthalocyanine were successfully recorded. Holography has been shown to be a useful tool to image beam‐sensitive and weak‐phase objects without artifacts.     

利用扫描电子显微镜改进GaAs MESFET背面通孔电镀工艺

利用扫描电子显微镜对ＧａＡｓＭＥＳＦＥＴ背面通孔形貌及电镀状况进行了分析，并对电镀工艺进行了改进。给出了大量改善前后的电镜照片图形。     

七种天蚕蛾科昆虫卵壳气孔的扫描电镜观察

应用扫描电镜观察了七种天蚕蛾科昆虫卵的气孔结构,发现在柞蚕Antheraeapernyi和天蚕A.yamamai的大型围壁式气孔及樟蚕Eriogyna pyretorum的气孔(无围壁)中均存在着一个特殊的档板样结构,而在天蚕的小型围壁式气孔以及绿尾大蚕蛾Actias selene、樗蚕Philosamia cynthia、蓖麻蚕P.cynthia ricina、栗蚕Dictyoplocajaponica的气孔中则无类似结构。这一结构在国内外尚乏明确、详尽记载。该档板样结构似乎仅存在于开口较大的气孔通道内,根据其超微结构和气孔实际开口状况,很可能是一种控制气孔开闭程度的调节机构,在大型昆虫卵胚胎发育期间的呼吸中起着重要的作用。     

疣状胃炎的电镜观察

对５０例疣状胃炎组织及１４例“正常”组织进行了电镜观察。在５０例病变处组织中，腺上皮细胞有形态改变的３４例，其间有炎细胞浸润的４０例，腺腔内有幽门螺旋菌感染的３０例。间质中有淋巴细胞、浆细胞、中性白细胞、肥大细胞及巨噬细胞浸润的分别为４２、３０、３８、３０和２８例。毛细血管扩张的４１ ，基质中多有不定形物及胶原原纤维。     

扫描电子显微镜在栅光刻工艺中的应用

阐述了扫描电子显微镜在解决栅光刻在线监测中遇到的问题和解决过程。在充分的理论分析基础上,通过大量实验研究,克服了光刻胶在高能电子辐照下变形、变性的问题;削弱了光刻胶样品表面荷电对图像质量的影响;在观测"T"型栅的胶窗口时采用特殊的工作条件获得了三层胶的立体形貌图像,从而能够观察三层胶的内部结构。上述问题的解决和技术的改进实现了栅光刻工艺的在线监测;并为栅光刻工艺的稳定和改进、产品成品率的提高提供了大量数据和图像。