两种夏柏特线虫头部扫描电镜结构的比较

两种夏柏特线虫头部扫描电镜结构的比较张路平１李纪标２刘书广１安瑞永１（河北师范大学生物系１，实验中心２，石家庄０５００１６）寄生于家畜体内的夏柏特属Ｃｈａｂｅｒｔｉａ线虫仅有三种，其中在我国已报道二种，即羊夏柏特线虫Ｃｈａｂｅｒｔｉａｏｖｉｎａ（Ｆａ...     

松材线虫和拟松材线虫扫描电镜结构的比较研究

本文对３个株系松材线虫和３个株系拟松材线虫进行了扫描电镜结构的比较。结果表明,雌虫尾突的特征、雌虫尾部纵脊的数目以及雄虫尾翼的结构是松材线虫和拟松材线虫分类的主要特征。其中雌虫尾部纵脊的特征是过去没有描述过的,这一发现为这两类线虫的分类鉴定提供了新的依据。     

线虫扫描电镜样品制备技术的比较

扫描电镜是线虫分类研究中不可缺少的重要工具.本研究利用昆虫线虫小杆属Rhabdtis sp.、三等齿属Pelodera teres、植物根结线虫三种线虫为试材进行了戊二醛固定和戊二醛-锇酸双固定技术、CO2临界点干燥和真空冷冻干燥技术及相互组合技术的比较研究.结果表明戊二醛一锇酸双固定和真空冷冻干燥组合的制样技术更适合线虫保持较好的形态结构,经该制样方法处理的线虫体表不易变形,为线虫扫描电镜制样可参照的方法.     

一例Citrin缺陷病患儿棘形红细胞的扫描电镜观察

目的：探讨Citrin缺陷导致的新生儿肝内胆汁淤积症（NICCD）红细胞形态变化。方法：抽取一例NICCD患儿治疗前和治疗后的静脉血作为研究对象,应用扫描电镜和透射电镜观察红细胞的超微结构。结果：在扫描电镜下,该NICCD患者治疗前正常红细胞数百分比仅为1.4%,而棘形红细胞高达红细胞总数的95.6%,其它异形红细胞为3.2%。治疗后,视野内几乎均为正常红细胞,偶见棘形红细胞。在透射电镜下,治疗前红细胞膜表面有棘状突起,治疗后红细胞膜表面光滑,大部分红细胞切面呈棒状。结论：该例NICCD患儿治疗前棘形红细胞显著增加,治疗后红细胞形态恢复为双凹圆盘形,提示红细胞超微结构改变。可作为Citrin缺陷病的临床病理诊断辅助指征。     

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     

油田注汽发生器锅炉结垢物的扫描电镜研究

利用热蒸汽吞吐工艺开采稠油是当前国内外开采稠油的主要形式之一。该技术的原理是利用湿蒸汽发生器产生高温高压的热蒸汽，热蒸汽注入含油地层，加热地层使得粘稠石油变稀，从而被抽提出来。从采油井口采出的油和水混合物经过油水分离，分离出来的水称为稠油污水。热蒸汽吞吐工艺采油技术一方面大幅度地提高了原油的产量，另方面也带来了大量的稠油污水。     

烟草叶片组织结构的扫描电镜观察方法

将烟草叶片经过固定、水解、剥离、降解、浸泡、置换、干燥、喷金等处理 ,成功地制备出了烟草叶片各层组织的扫描电镜样品 ;首次获得烟草叶片各组织层的立体结构图像 ,通过比较 ,发现不同部位叶片内部组织结构存在某些规律差异。为研究烟草叶片各组织层中细胞分布和生长发育规律提供了一条新的途径。     

云南松树上三种伞滑刃线虫扫描电镜制样技术研究

伞滑刃属松材线虫(Bursaphelenchus xylophilus)是中国林业上重要的外来入侵病虫害之一，是当前我国林业上的头号病害。     

肠道杆菌的扫描电镜观察

我们用扫描电镜观察肠道杆菌种(Enterobacteriaceae)中的四种细菌,大肠埃希氏杆菌(Escherichiacoli),普通变形杆菌(Proteus vulgaris),伤寒沙门氏菌(Salmonella typhi)和福氏志贺氏菌(Shigella Flexneri)。未处理的菌落标本,菌落表面都可形成一层厚薄不同的表膜(Surface film)。四种细菌菌落的表膜,形状不一,千姿百态。适当处理后的菌落标本,则可显示菌体的本来面目。四种细菌菌体在菌落表面的分布和排列,也是各不相同,千差万别。本文根据扫描电镜的观察,对四种不同菌落进行了讨论。     

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。     

Silicon electron multiplication (SEM) camera tube

A low-light-level television camera tube has been realized, which incorporates a silicon electron multiplication (SEM) target. Image electrons liberated from the photocathode bombard the target, causing an electronic amplification of several thousand, as well as electronic charge storage. The SEM tube shows a limiting sensitivity at photocathode illumination on the order of 10^-5lx, and approaches the picture degradation problem due to quantum fluctuation. Further degradation of the picture is observed by addition of an image intensifier tube to the SEM tube, and also in the case of an X-ray image pickup using the SEM camera with phosphor screen. The SEM tube can scarcely be injured by the exposure to a strong light.     

SEM direct observation of the degradation in Ga(Al)As GRIN-SCH lasers grown on a silicon substrate

The starting of the degradation in GRIN-SCH GaAs lasers grown on a silicon substrate was directly observed by EBIC and CL techniques. The investigation of electron beam induced damage shows that the degradation of these devices starts in the p-n junction before it attains the active layer and before the appearance of dark line defects.<>     

雪峰虫草寄主巨疖蝙蛾成虫触角感器扫描电镜观察

利用扫描电镜对雪峰虫草(Ophiocordyceps xuefengensis)重要寄主巨疖蝙蛾(Endoclita davidi)成虫触角上的感器进行了观察和描述.结果表明,巨疖蝙蛾雌雄成虫触角均为丝状,分布有毛形感器、刺形感器、锥形感器、腔锥形感器、板形感器、鳞形感器和B(o)hm氏鬃毛7种感器.其中,刺形感器、锥形感器、腔锥形感器和板形感器只分布于鞭节;毛形感器在柄节和鞭节均有分布;B(o)hm氏鬃毛分布于雌、雄的柄节和梗节的基部;鳞形感器在各节均有分布,尤其在鞭节的种类和数量最多.雌、雄个体间触角感器类型及分布未见明显差异.     

扫描电镜样品制备的改进方法用于纤毛虫特氏前口虫皮层的观察

人们观察纤毛虫或其他细胞表膜内表面结构的方法是利用透射电镜.但观察到的均为二维图像,展示其形态结构的三维图像尚未有过报道.本文介绍了本实验室在扫描电镜样品制备的破膜方法基础上,在特氏前口虫上的新改进.此改进的方法展示了应用于特氏前口虫后,所获得的表膜内表面皮层下三维立体结构观察的效果,从而为相关领域的研究者应用扫描电镜...     

Practical SEM system based on the montage technique applicable to ultralow-magnification observation, while maintaining original functions

A newly developed SEM system has been utilized for obtaining ultralow-magnification SEM images. It is a successful combination of the modern SEM equipped with a motor drive stage fully controlled with PC and digital image processing techniques for automatic montage. In order to accomplish a practical system, several problems peculiar to the field of SEM, i.e. raster rotation, peripheral distortion and charging effects, are discussed and solved. The function of ultralow-magnification (whole area) observation is important during a scanning electron microscopy session.     

椪柑体细胞胚胎发生的扫描电镜观察

扫描电镜观察表明,椪柑胚珠离体培养的体细胞胚胎发生过程与双子叶植物合子胚的发育过程相类似,并可发育成完整植株。文中还对各阶段胚状体的形态特征和细微结构进行了观察和描述,以期为体细胞胚胎发生的早期鉴别和深入研究提共新的资料。     

Microcharacterization of electroluminescent diodes with the scanning electron microscope (SEM)

A complete material characterization of electroluminescent diodes necessarily requires a high spatial resolution because of the micron-sized thickness of the different epitaxial layers. A modified arrangement of a scanning electron microscope (SEM) has proven to be an extremely useful tool for obtaining information on the various parameters of each of these layers. It will be shown that the analysis of the electron beam induced voltages (EBIV) and currents (EBIC) allows not only the location of the junction itself, but also the detection of all other built-in barriers. Measurements of the EBIC permit separation of barriers less than 1 µm apart; even barriers in a direction oposite to that of the junction are detected in this manner. The peak value of EBIC is largely independent of the barrier height, but it is sensitive to variations in the concentration of the components of the lattice. Because of the exponential decrease of EBIC with the distance between primary electron beam and barrier, the minority carrier diffusion length can be obtained for all different barriers. The height of barriers, 2.5 µm separated and with the same direction as the p-n junction, can be determined quantitatively by the maximum of EBIV. By measurement of the cathodoluminescence (CL) signal regions of different recombination probabilities for radiative transitions (and therefore different luminescence yields) can be distinguished. Thus inhomogeneities of the structure can be detected. By spectral CL analysis the spatial variation of the width of the bandgap will be shown.     

Investigation of intermetallic compounds (IMCs) in electrochemically stripped solder joints with SEM

In this work we compare the microstructures of intermetallic compounds (IMCs) in electrochemically stripped solder joints created by two different soldering methods (vapor phase soldering (VPS), and selective laser soldering with a CO₂ laser). After the selective removal of the Sn phase with amperometry, the microstructure and structural composition of the IMC can be revealed in a detailed way, which is unlike any other previously published methods. The differences between the IMC microstructures of the technologically different solder joints were analyzed with optical microscopy and scanning electron microscopy (SEM). Energy dispersive spectroscopy (EDS) measurements were utilized to identify the different intermetallic phases (Ag₃Sn, Cu₆Sn₅). Significant differences were observed in the IMC structures of solder joints prepared by different technologies.     

Macro and Micro-Scale Features of Thermoelectric PbTe (Br,Na) Systems: Micro-FTIR Spectroscopy,Micro-Seebeck Measurements,and SEM/EDX Observations

In this work, n-type and p-type PbTe doped with Br and Na, respectively, were thoroughly examined to determine the effect of the dopant on microstructure. Macro and micro homogeneity of the samples were studied by means of micro-Fourier-transform infrared (micro-FTIR) spectroscopy, micro-Seebeck measurements, and scanning electron microscopy with energy-dispersive x-ray analysis (SEM/EDX). SEM/EDX observations showed the samples were not single-phase materials—second phases were created by inclusions that disturbed the coherence of the matrix and, subsequently, drastically affected the Seebeck coefficient. In a micro-scale study, local variations of sodium content were detected in Na-doped samples; in Br-doped samples a second, PbBr₂, phase was observed in the PbTe matrix. A direct effect of matrix dopant on Seebeck coefficient and plasmon frequency for the Br-doped and Na-doped samples was observed by use of the three complementary techniques.     

Design of a Secure Encryption Model (SEM) for Cloud Data Storage Using Hadamard Transforms

Wireless Personal Communications - Data storage has been one of the most prevalent services that has been offered by cloud computing. One of the challenges associated with data storage has been the...