7种云杉属树种花粉形态特征及其系统学的意义

通过扫描电镜观测了云杉属7个种的花粉形态,运用数据统计和图片分析的方法对花粉形态进行对比研究.结果显示:云杉属7个种的花粉大小变动范围为84.59～103.18 μm,均属于两气囊松科花粉;花粉体近极面与气囊过渡明显,形成帽沿;气囊表面纹理较平滑,在种间变异不显著.萌发沟位于花粉体远极面两气囊之间,呈现沟痕的形式.根据...     

图像处理系统在花粉测定中的应用

图像处理系统在花粉测定中的应用吴平林钧安（沈阳农业大学电镜室，沈阳１１０１６１）生物显微和超微结构的图像分析处理技术主要是指光镜与电镜图像的计算机处理技术。本文简介了中国科学院科学仪器厂生产的ＫＹ－ＥＭＩ－１型图像处理系统的组成、功用，并以观察旱柳花...     

4种睡莲花粉形态的扫描电镜观察

本文采用扫描电镜技术对4种睡莲(雪白睡莲、万维莎、伊丽莎白、蓝美人)的花粉进行了形态学研究。结果显示,4种睡莲花粉极面观为近圆形,萌发孔均为环槽类型;雪白睡莲、万维莎和伊丽莎白均为左右对称型的异极花粉,而蓝美人为辐射对称型的等极花粉;雪白睡莲和万维莎属于中等花粉类型,伊丽莎白和蓝美人属于小花粉类型。4种睡莲除雪白睡莲外,其他3种睡莲花粉形态特征均为首次报道,为睡莲属植物的分类和进化关系研究提供了直观的孢粉学依据。     

水稻亚种杂种F_1小孢子和花粉发育的超微结构

众所周知水稻亚种间杂种优势明显高于品种间优势。但亚种间杂种F_1代结实率低,至今尚不能在产上直接利用。自从Ikehashi和Araki(1984)从爪哇型水稻中发现了CPSLO_(17)等广亲和性基因品种,为水稻亚种间杂种优势利用开辟了新的途径。在水稻广亲和基因的遗传及其利用方面已经做了一些工作,但迄今未见以广亲和品种配种亚种间杂种花粉育性的超微结构研究报道。本文对水稻亚种间广亲和性和不亲和性杂交组合F_1代的小孢子发生和花粉发育进行了电镜比较观察,得到如下结果:     

茶树花粉的扫描电镜观察

植物的花粉学及花粉分析一向是研究植物种源、分类和亲缘关系的一种方法。但是用扫描电镜来研究茶树花粉结构以及种系间的关系,国内外尚未见系统的报导。扫描电镜具有倍率高、焦深长和制样简便等优点,它对观察花粉或其他组织的细微结构,提供了强有力的手段。取经水解液清洗干净的茶花粉,用日立HUS—5 GB高真空镀膜机进行涂金处理后,再用日产JMSF—50型扫描电镜观察并摄影,通过对我国大、中小叶种及野生类型等十余个茶树品系的花粉观察后得出:茶树花粉有很强的种特征,尽管品系和生态环境不同,茶树花粉的基本形态和结构是比较稳定的,均属二侧对称的球形花粉。沟在极区不会合,将花粉分为三个明显的沟间区和沟界极区,具沟     

异质结构中载流子输运的二维自洽全能带系综蒙特卡罗模拟

本文展示了一个用于异质结构模拟的二维全能带系综蒙特卡罗 模拟器,它通过自洽求解二维泊松和波尔兹曼方程,同时处理 了载流子在两种不同半导体材料以及其其界面处的输运。本文 给出了该蒙特卡罗模拟器的内部结构,包括通过赝势方法计算 得到全能带结构、包含的不同散射机制和对载流子在两种不同 半导体材料边界输运的适当处理。作为验证,我们对两种不同 掺杂的Si-Ge异质结—p-p同型异质结和n-p异型异质结进行了 模拟,给出了其I-V特性以及电势和载流子浓度分布,这些结果 验证了我们的异质器件蒙特卡罗模拟器的有效性。     

青扦花粉萌发及花粉管生长过程中的钾离子流及BaCl2和TEA的影响

本文以裸子植物青扦花粉为材料,运用非损伤、选择性电极技术探究了花粉水合、萌发及花粉管生长过程中的钾离子流,以及抑制剂处理后的影响.研究结果显示:(1)钾离子通道抑制剂BaCl2和TEA(氯化四乙胺)处理推迟花粉萌发;(2)BaCl2和TEA处理后,青扦花粉萌发和花粉管伸长均受到抑制;(3)选择性电极检测结果显示对照花粉不同发育时期钾离子均内流,即花粉水合、萌发及花粉管生长均需大量的钾离子.BaCl2和TEA处理后,花粉的钾离子流动态也随之发生改变.培养3~9 h,钾离子呈明显的外流,12~21 h钾离子内、外流基本平衡,24 h钾离子内流.抑制剂处理导致的钾离子流的紊乱使得花粉不能正常萌发、花粉管不能正常生长.因而,钾离子在青扦花粉萌发及花粉管生长过程中具有重要的调控作用.     

十六例进行性肌营养不良症的超微结构研究

进行性肌营养不良症是一组有显著遗传因素、并以某些肌群非炎性进行性病变为主要特征的原发性肌肉疾病,严重者最终可致瘫痪。临床上根据病变肌群不同和临床特点不同将其分为若干类型,其共同临床表现为进行性肌无力。近来,国外一些学者使用电镜对某些类型的肌病作过研究,但临床分型混淆现象仍然存在。本文希望通过对病肌的电镜观察,了解不同类型肌营养不良症的超微结构病变特征,以期为临床确诊提供帮助,为深入研究本病病理提供参考。[材料和方法]病肌活检材料16例,其中假性肥大型9例、肢带型3例、面肩肱型3例、眼肌型1例。活检部位腓肠肌(10例)和三角肌(6例)。标本常规处理作电镜观察。[结果和讨论]各型肌病没有     

电镜自动真空系统的微机控制

电镜真空系统的自动控制一般采用逻辑电路控制和微机控制。在目前国内所拥有的进口电镜中,都是采用逻辑控制。我们在研制DXS-3型高性能扫描电镜中对这两种控制方法进行了分析,我们认为:微机控制采用的是大规模集成电路,电路简单,成本较低,维修方便;由于采用的软件控制,故能够灵活地设置抽气状态,且通用性强。 DXS-3型扫描电镜的真空系统,具有上台和下台两种抽真空方式,同时还配备有上样品室和下样品室两种换样气锁室的予抽真空系统和枪室换灯丝予抽真空系统(见图1)。为了使这样一个复杂的真空系     

白血病的电镜诊断

应用电镜分别对5例不同类型白血病患者骨髓穿刺细胞进行了观察,观察结果表明例一、二均为急性早幼粒细胞白血病,两例骨髓细胞中均见有许多异常早幼粒细胞胞浆内含有Auer小体,但两例细胞内Auer小体结构呈明显差异,例三、四为不同类型毛细胸白血病,即典型毛细胞白血病（Ⅰ型）及变异型毛细胞白血病（Ⅱ型）,两型细胞在结构上的差异主要表现为细胞膜表面毛样突起的长度及数量不同,变异型毛细胞白血病细胞的特点仅在电镜下才能辨认。例五为急性粒细胞白血病的部分分化型,其中早幼粒细胞胞浆内仅具极少数小的电子致密颗粒,电镜对该种细胞的分辨显示出光镜所不具有的优势,并提示电镜在白现诊断中的重要意义。     

多孔硅薄膜微结构的分形特性

用扫描电镜(SEM)对厚度不同的多孔硅膜的微结构进行了研究。对于23μm厚的多孔硅膜,其横截面微结构好似海底生长的海藻;而对于6μm厚的多孔硅膜,其表面微结构则像龟壳上的裂纹。通过对在不同放大倍数情况下拍摄的多孔硅的SEM图片进行分析,结果表明多孔硅薄膜的这两种微结构都具有分形特征,而且其分形维数为2.3～2.6。利用扩散限制凝聚模型(diffusion limited aggregation)对这两种微结构的形成过程进行了模拟。     

Microrobot System for Automatic Nanohandling Inside a Scanning Electron Microscope

In this paper, current research work on the development of an automated nano handling station in a scanning electron microscope (SEM) is presented. An experimental setup is described, in which two mobile microrobots cooperate in the vacuum chamber of an SEM. The robots are positioned by a closed-loop controller with sensor data, which is provided by three charge-coupled device cameras and the SEM. Continuous pose estimation is carried out by processing noisy SEM images in real time. To enable the automation of complex tasks, a client-server control system that can integrate various microrobots and sensors is introduced. Finally, the overall system is evaluated by automatic handling of transmission electron microscope lamellae.     

Activation process-dependent characteristics of novel thermionic oxide cathodes for CRT application

The emission and conductivity characteristics of oxide cathodes depend largely on the activation process. In this paper, the electrical properties of new type of oxide cathodes for cathode ray tube (CRT) application, supplied by LG Philips Displays, have been investigated in relation to different cathode activation regimes. The influence of the activation process over different durations has been investigated. A temperature of T=1425 K was chosen to be higher than the optimum cathode activation temperature (T=1200 K), and the other temperature of T=1125 K was lower than that. The electron activation energy (E) was found to vary in the range from 0.58 to 2.28 eV for cathodes activated at the higher temperature regime, and from 1.08 to 1.9 eV for those activated at the lower temperature regime. Scanning electron microscopy (SEM) and electron diffraction X-ray (EDX) analyses show a structural phase transformation in the oxide material that was activated at 1125 K for a period of 1-12 hours. The SEM mapping shows a large contamination of Ba in the top layer of oxide material. The activator agents tungsten and aluminum are found to penetrate into the BaO/spl bsol/SrO layer in two different ways.     

两种微米金刚石聚晶颗粒薄膜的制备与场发射研究

采用微波等离子体化学气相沉积,在不同的沉积条件下得到两种微米金刚石颗粒薄膜,通过拉曼光谱仪和X射线仪分析了两种薄膜的成分,用扫描电子显微镜分析了两种薄膜的表面形貌,用二级结构的场发射装置研究了薄膜的场发射性能,最终分析并讨论了场发射性能优异的微米金刚石薄膜的特征。     

确定ZnO颗粒生长方向的电子背散射衍射方法

发展了利用扫描电子显微镜(SEM)与电子背散射衍射系统(EBSD)对微晶颗粒空间取向进行表征的新方法,对以气相氧化方法制备的纳米晶ZnO颗粒的生长方向进行了测量.在样品台两个不同的倾转角度下采集两幅ZnO颗粒图像,对这两幅图做图像分析,测量各枝晶臂在样品台不同倾转角时的投影角度,可以确定ZnO颗粒枝晶臂的生长方向在样品台坐标系中的空间取向,并获得各枝晶臂的长度和夹角.由EBSD确定ZnO颗粒对应的枝晶臂晶格坐标与样品台坐标之间的空间几何关系.并根据坐标变换关系可确定枝晶臂空间生长方向的晶体学取向是沿[0001]方向.     

Electron microscopy characterization of airborne micro- and nanoparticulate matter

The aim of this work was to offer a state-of-the-art critical survey for characterizing airborne nano- and microparticles by means of electron microscopy (EM) techniques and to highlight advantages and limits of different possible operation modes. Procedures of collection and sample preparation are revisited and improved to analyse airborne particles deposited on filtering membranes by using various sampling methods. Three kinds of electron microscopes are used to this end: scanning electron microscope (SEM), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Following and extending previous studies, we optimized procedures by varying both the sample collection/preparation and the operational parameters of the microscopes. In particular, we diversified the sampling methods applied, using ad hoc filters as well as common filters for standard gravimetric measures. This approach enabled us to achieve a simple and clean procedure allowing direct SEM or TEM observation of the collected particulate matter.     

多孔硅秃腔微结构的AFM和SEM研究

多孔硅微腔是采用交替变化脉冲腐蚀电流密度的方法制成的多孔度周期性变化的多孔硅结构。用原子力显微镜（AFM）和扫描电子显微镜（SEM）对多孔硅微腔的侧向解理的截面进行了观测，得到了不同多孔层及其界面处的图像。微腔截面的扫描电镜图像清楚地显示出第Ⅱ型多孔硅微腔的“三明治”结构，即中心发光层被夹在两个Bragg反射镜之间，这些结果表明结合分子束外延技术和电化学腐蚀方法可以很容易得到多孔硅微腔。     

双相不锈钢冷轧退火组织转变的EBSD原位研究

本文采用扫描电子显微镜（ SEM）及电子背散射衍射（ EBSD）技术对经30％压下量冷轧的双相不锈钢UNS S32304在1050℃下退火的显微组织转变进行了原位追踪。结果表明,轧制变形后,两相的变形抗力具有明显差异,奥氏体塑性变形量较比铁素体大;经1050℃真空退火2 min后,两相晶内取向差的变化表明铁素体较比奥氏体发生了更大程度的回复;再经1050℃真空退火5 min后,样品中两相晶粒取向与其初始取向具有较大差异,表明发生了以再结晶为主并伴有少量相变反应的组织变化。     

Fabrication of potential NiMoP diffusion barrier/seed layers for Cu interconnects via electroless deposition

Potential NiMoP barrier/seed layers for Cu interconnects have been successfully formed by electroless deposition on SiO₂. Four different wet processes were attempted to activate the surface before electroless deposition. Material properties including the crystal structure, deposition rate, composition, and electrical resistivity of NiMoP layers were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), Auger electron spectroscopy, x-ray diffraction (XRD), four-point probe, and surface profilometry (Alpha-step). In this study, different compositions of NiMoP films have been obtained. Ni₈₉Mo₂P₉ with nanocrystalline structure has the highest resistivity due to enriched P content, while Ni₈₈Mo₉P₃ has the lowest value among the compositions considered in this study. The seed layer and the barrier layer functions of NiMoP were verified by direct Cu electrodeposition and secondary ion mass spectroscopy (SIMS).     

Toluene Sensing Properties of P4VP/Multi-Walled Carbon Nanotubes Multi-Layer Film Sensors

Poly4-vinylphenol (P4VP)/multi-wall carbon nanotubes (MWNTs) multi-layer sensitive films were deposited on interdigitated electrodes by airbrush technology to detect toluene vapor at room temperature. The surface and section morphologies of the multi-layer films were observed by a scanning electron microscope (SEM). It is found that the resistance of the sensor increases when it is exposed to toluene vapor and the response has a good linearity with the concentration of toluene. The results show that the P4VP/MWNTs three-layer film sensors have better sensing properties compared with the two-layer film sensors. The related sensing mechanism is studied in detail.