肾蕨离体培养过程中形态发生的扫描电镜观察

肾蕨离体培养过程中形态发生的扫描电镜观察冯莉，田兴山，李庚午，朱命炜（河南师范大学，新乡４５３００２）本文利用肾蕨（Ｎｅｐｈｒｏｌｅｐｉｓｃｏｒｄｉｆｏｌｉａ）根状茎尖进行离体培养，在获得再生植株的基础上，对其形态发生过程进行扫描电镜观察，以期为蕨类...     

Observation of dislocations in a silicon phototransistor by scanning electron microscopy using the barrier electron voltaic effect

Silicon planar phototransistors crossed by slip planes were examined both by X-ray topography and by conductive mode scanning electron microscopy using the barrier electron voltaic effect current as video signal. Only a few of the dislocations visible in the topographs gave rise to contrast in the scanning electron micrographs. This observation of single dislocations by means of the barrier electron voltaic effect is particularly valuable for the study of the role of defects in device failure and production yields as it renders visible only the electrically effective defects. Quantitative analysis of the barrier electron voltaic effect short circuit current obtained on scanning across an electrically effective dislocation provides a new means for measuring the electrical properties of dislocations. Repeated scanning produced lines of enhanced contrast across the surfaces of the devices. These lines were visible in surface X-ray topographs. This observation is believed to be due to beam induced damage in the oxide and interface region.     

扫描电镜研究硝酸纤维素膜上的共结晶

MAL DI- TOF- MS以其“高灵敏度、宽分子量范围、允许混合样和一定量盐”的特点而成为蛋白质分子量测定的重要手段。但由于一些变性剂和无机盐常与样品竞争结晶 ,不但会大大抑制样品信号 ,而且会产生一些难以解析的离子峰。因此 ,测试前应尽可能除去样品中的添加剂。而将蛋白质吸附或印迹到转移膜上是除去干扰物的重要方法之一[1] 。固定在金属靶上进行 MALDI-TOF- MS分析的转移膜 [2 ] ,应满足以下要求 :能吸附蛋白质和肽 ;在操作样品过程中样品不丢失 ;干燥后的膜上蛋白质应能很好地重新溶剂化 ;蛋白质和基质均应在膜表面结晶。而…     

纤维素酶固态发酵环境扫描电镜观察

纤维素酶压力脉动固态发酵周期（60h）比传统固态发酵周期缩短1/3，酶活（2036IU/g）比传统酶活（10.82IU/g）提高了一倍。利用环境扫描电镜观察压力脉动固态发酵与传统固态发酵微观动态过程表明，压力脉动固态培养的料层（9.0cm厚）上中下微生物生长状况均匀一致，且疏松；而传统固态发酵的料层中部几乎没有菌体生长。并且发现微生物产孢初期，其产酶即停止，压力脉动固态发酵在72h开始产生孢子，其产酶达到最高峰；而传统发酵在96h才出现大量的孢子。     

同步糖化发酵过程中纤维素降解的环境扫描电镜观察

利用环境扫描电镜观察了纸浆纤维素在同步糖化发酵(Simultaneous saccharification and fermentation，SSF)产酒精过程中的降解，并与单一酶解过程进行比较。在单一酶解过程中，由于纤维素酶解产物的积累，形成了对纤维素酶的反馈抑制，纸浆纤维素降解较慢。在SSF过程中，纤维素的酶解产物由于被酵母及时转化为酒精，没有形成对纤维素酶的反馈抑制，纸浆纤维的降解较快，而且过程中纤维素含量和酒精含量的变化测定结果与电镜观察结果一致，表明SSF能有效提高纤维素的酶解效率。在SSF后期，半纤维素的主要酶解产物戊糖由于不能被酵母利用而大量积累，有可能对半纤维素酶形成了反馈抑制，造成了半纤维素的降解困难。     

趾甲镰刀菌病真菌的扫描电镜观察和特殊制样方法

本文经反复摸索对比,总结出一套简便、完整、快捷的真菌扫描电镜（SEM）样品制备方法,并对分离培养趾甲镰刀菌病的镰刀菌（Fusarium,F）进行了表面超微结构观察。在SEM下可清晰地分辨出真菌的菌丝和大、小分生孢子。茵丝粗细均匀,形态饱满,表面有较规律且微微隆起的分隔,其上偶有分支,彼此连通。大、小分生孢子则以孢尖或孢体依附贴合于菌丝上,其中大分生抱子较稀疏,呈镰刀形或纺锤形,两端较尖,孢体稍弯曲,背腹明显,有2～5个环状竹节样膨隆,其中小分生孢子较密集,呈卵圆形或梨形,无或偶见一隔膜,且两种孢子均有顶端和侧壁出芽。SEM观察结果为真菌的病原学分类和抗真菌药物筛选等方面提供了形态学依据。     

Scanning electron mirror microscopy and scanning electron microscopy of integrated circuits

The recently developed scanning electron mirror microscope (SEMM) is compared with other types of electron microscopes, such as the electron mirror microscope (EMM) and the scanning electron microscope (SEM), for examining integrated circuits. Potential advantages of the SEMM include high resolution, elimination of electron bombardment damage, and high sensitivity of voltage gradients, magnetic fields, and topography. Preliminary observations of integrated, circuits obtained with the feasibility SEMM at various specimen potentials are discussed.     

小孢子真菌发癣患儿毛干超微结构改变的扫描电镜观察

为了唤起社会关注及探究发癣的超微病理变化,提醒社会及家庭,尽量使儿童远离宠物或不养宠物,减少任何可能的传染源。本文对6例确诊为小孢子菌癣患儿的毛发,按常规制备扫描电镜样品,扫描电镜下观察分析。结果显示小孢子菌对毛干损害部位主要在毛小皮,而毛干主体的皮质柱则少见损伤。毛小皮细胞的超微变化特征在于使原来呈叠瓦且贴附平整规律的毛小皮,逐步干裂翘起失去固有形象,毛干逐渐由圆滑润泽变成毛刺状,最后导致毛小皮细胞解体或脱落,毛根松动,毛干易折断。上述超微结构改变可能与毛小皮硬角质受体蛋白分子有关。     

Histochemistry of food tissue by colour scanning electron microscopy

A low-vacuum scanning electron microscope (SEM) allows microscopy of insulating specimens without metal coating, and so preserves the intact colour information on the specimen surface. We have attempted a new approach to characterize constituent distribution of food tissues by a histochemical method utilizing a colour SEM with an optical microscope and the low-vacuum SEM through digital image processing. To observe food tissues such as brown rice and adzuki bean, a colour SEM image of the specimen that has been stained by a modified method used in optical microscope histochemistry has proved to provide information of both the microscopic structure and constituent distribution on the specimen surface.     

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.     

单晶硅摩擦致相变的SEM研究

自从Jamieson发现单晶硅的高压相变现象以来，有关单晶硅的高压相变的研究逐步开展起来，其最终目的之一就是通过金属延性相的出现来解决单晶硅的加工问题。Pharr、Gogotsi、zhang liangchi等人利用纳米压入技术系统研究了单晶硅的压力致相变问题。本文旨在研究单晶硅在滑动摩擦过程中的相