[en] The megaspore morphology of 15 species of the genus Selaginella P. Beauv. (Selaginellaceae Willk.) using scanning electron microscopy was carried out. Of the 15 species, megaspore morphology S. arbuscula and S. drepanophylla are reported for the first time. On the basis of megaspore surface ornamentations five major megaspore types are recognized: granulate, tuberculate, verrucate, verrucate-rugulate and reticulate. The morphological characteristics of megaspores are useful in the subgeneric classification. However, the classification using megaspore morphological characteristics showed disagreement with the classifications reported in the literature. Therefore, the subgeneric relationships of the genus Selaginella need to be further studied. (author)

[en] A dynamic transmission electron microscope (DTEM) has been designed and implemented to study structural dynamics in condensed matter systems. The DTEM is a conventional in situ transmission electron microscope (TEM) modified to drive material processes with a nanosecond laser, 'pump' pulse and measure it shortly afterward with a 30-ns-long probe pulse of ∼10⁷ electrons. An image with a resolution of <20 nm may be obtained with a single pulse, largely eliminating the need to average multiple measurements and enabling the study of unique, irreversible events with nanosecond- and nanometer-scale resolution. Space charge effects, while unavoidable at such a high current, may be kept to reasonable levels by appropriate choices of operating parameters. Applications include the study of phase transformations and defect dynamics at length and time scales difficult to access with any other technique. This single-shot approach is complementary to stroboscopic TEM, which is capable of much higher temporal resolution but is restricted to the study of processes with a very high degree of repeatability

[en] The crystal lattices and crystal structures of franckeite and cylindrite have been restudied using transmission electron microscopy. The selected-area diffraction, convergent-beam diffraction and high-resolution electron microscopy observations revealed that the relations between the two lattices and between the lattice and the structure modulation are various and incommensurate. Revised structure models of cylindrite and franckeite are proposed from the application of the structural principles found to form the basis of the crystal structure of angitorite for explanation of sinusoidal modulations in these minerals. The simulated and observed high-resolution electron microscopy images match very well. The crystallo-chemistry of cylindrite and franckeite is also discussed. (orig.)

[en] A theoretical investigation of this study deals with the opossibility of designing aprojector lenses free of rodial and spiral distortion and the possibility of designing a favourable energizing coil for a magnetic lens which gives favourable objective focal properties under the presence and absence of magnetic saturation. The importance of this research lies in (a):the possibility of designing distortion-free doublet projector lenses for the projection of rotation-free images in the transmission electron microscope (TEM) and, (b):determining a favourable design of the enerqizing coil for the objective lensin the (TEM) and scanning transmission (STEM) electron microscope. (2 tabs., 77 figs., 50 refs.)

[en] This work describes a system for precise re-location of cells within a monolayer after atomic force imaging. As we know little about probe interaction with soft biological surfaces any corroborative evidence is of great importance. For example, it is of paramount importance in living cell force microscopy that interrogated cells can be re-located and imaged by other corroborative technologies. Methodologies expressed here have shown that non-invasive force parameters can be established for specific cell types. Additionally, we show that the same sample can be transferred reliably to an SEM. Results here indicate that further work with live cells should initially establish appropriate prevailing force parameters and that cell damage should be checked for before and after an imaging experiment

[en] This paper provides a broad background for the historical development and modern applications of light optical metallography, scanning and transmission electron microscopy, field-ion microscopy and several forms of scanning probe microscopes. Numerous case examples illustrating especially synergistic applications of these imaging systems are provided to demonstrate materials characterization especially in the context of structure-property-performance issues which define materials science and engineering

[en] A condenser-objective lens is designed through combination of separating and integrating to consider the effect of the front condenser field on its objective performance. A practical lens model including magnetic pole piece, magnetic circuit and coil windings is built to optimize its rear field. The front field can be integrated into the rear one by simply adjusting the position of the specimen and the excitation on the condenser-objective lens. Optical performance of the integrated lens is researched as both a condenser lens and an imaging one. The total aberrations at the specimen plane are 0.01nm under STEM operation mode and its spherical aberration coefficient is 1.5mm when being an imaging objective lens, which can meet for high resolution microanalysis and TEM imaging.

[en] A novel sample holder that enables atomic force microscopy (AFM) tips to be mounted inside a scanning electron microscopy (SEM) for the purpose of characterizing the AFM tips is described. The holder provides quick and easy handling of tips by using a spring clip to hold them in place. The holder can accommodate two tips simultaneously in two perpendicular orientations, allowing both top and side view imaging of the tips by the SEM.

[en] Hierarchical micro-nanostructured surfaces are key components of ‘smart’ multifunctional materials, used to control wetting, adhesion, tactile, friction, optical, antifogging, antibacterial, and many more surface properties. Hierarchical surfaces comprise random or ordered structures ranked by their length scale spanning the range from a few nanometers to a few micrometers, with the larger microstructures typically embedding smaller nanostructures. Despite the importance of hierarchical surfaces, there have been few studies on their precise and controlled fabrication or their quantitative characterization, and they usually involve multiple and complex fabrication steps. Here, we present a new plasma nanotechnology, which we term ‘nanoinhibit’, and a new plasma reactor for producing in one facile process-step-controlled hierarchy at will on polymeric surfaces. We couple the new plasma nanotechnology with detailed computational nanometrology based on the analysis of scanning electron microscopy images and targeted to specific functionality. We showcase the potential of ‘nanoinhibit’ for functional surface fabrication by controlling the wetting and optical functionality of the fabricated hierarchical surfaces and showing its dependence on surface morphology metrics. Finally, we observe that ‘nanoinhibit’ produces a new class of ‘strong hierarchical’ surfaces exhibiting spatially separated periodic and fractal-like components. (paper)

[en] This work presents strong evidence for structural damage accumulation as a function of shear strain admitted by shear bands in a Zr-based bulk metallic glass. Analyzing the shear-band structure of shear-band segments that experienced shear strains covering four orders of magnitude with high-angle annular dark field transmission electron microscopy (HAADF-STEM) reveals strongly scattered data with on overall trend of increasing local volume dilatation with increasing shear strain. Locally, however, a variety of trends is observed, which underlines the strong heterogeneity of structural damage in shear bands in metallic glasses.