ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03909.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryMicroscopy poses special problems of communication because it reveals completely unfamiliar images to the eye. During the eighteenth century, scientific societies, private letters and the sale of standard specimens satisfied the largely amateur interest in microscopy. The need to illustrate texts came rather later than might be expected, however, because the development of the optics of the instrument was very slow between its invention in about 1600 and the discoveries of J. J. Lister in the 1830s. In the second half of the nineteenth century the microscope increased in scientific importance, creating a need for rapid and efficient means of communicating results, to which photography and new printing techniques were essential. This development is illustrated with special reference to the publications of the Royal Microscopical Society.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03910.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryBefore the introduction of the electron microscope for cytological research around 1940, indirect methods were used for disclosing sublight‐microscopic structures. The results obtained by macromolecular chemistry were combined with those from investigations made with polarized light and by X‐ray diffraction. The application of Wiener's theory of composite bodies proved the presence of rodlet and lamellar ultrastructures, and the X‐ray analysis gave information on the crystallinity and the size of the components of such structures.Both methods are based upon regular periodicities in the object investigated, so that their application is limited. Nevertheless, most of the conclusions concerning ultrastructural morphology gained with these techniques were corroborated when direct images of the relevant ultrastructures could be produced by electron micro

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03911.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryIn the field of quantitative investigation of microscopic images reflectance measurements with the aid of photoelectric equipment play an important role. Reflectances can be used for the identification of various components in a polished specimen, for chemical analysis and for the determination of the refractive index of a specimen as well as for a determination of the various absorption parameters of reflecting solid material.The parameters involved are: reflectances at given wavelengths, spectral reflectance curves in the visible, UV‐, and near IR‐spectral range, reflectances of optically anisotropic surfaces at varying orientations of the vibration plane of linearly polarized light, reflectances in air and in an immersion liquid (mainly in standard immersion oil). From spectral curves, quantitative expressions of colour can be derived. Due to improvements in reflectance standard materials and technical design of apparatus the measurements and calculations can be carried out very conveniently, quickly and precis

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03912.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryConventional preparative procedures for the examination of tissues in the electron microscope involve the use of fixatives, dehydration in alcohol or acetone, embedding in plastics and staining. Such procedures remove soluble components and are therefore often unsuitable for chemical analysis of naturally occurring electrolytes. Ultrathin frozen sections of unfixed, unembedded biological tissue can be cut onto dry glass knives, freeze‐dried and viewed in the electron microscope without staining. Morphological detail is sufficient to identify cell types and ultrastructure. X‐ray microanalysis in the analytical electron microscope (EMMA‐4) has shown that highly soluble electrolytes can be detected and that intracellular compartments are ret

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03913.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryA direct colour superposition technique has been used to study two dislocations in W, using He field‐ion imaging at 77°K. Limitations due to instrumentation and field‐ion microscopy are discussed. A single spiral and a double spiral on (112) W were each dissected, by field evaporation, through three successive atom layers, and apparent core shapes and dimensions were determined. The shapes were irregular with diameters of at most 0.5–2 nm for the single spiral and 0.5–1.7 nm for the double spiral. Observed displacements in the positions of the core regions may be associated with dislocation movement induced by the high electric field needed for the obse

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03914.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryIn Scanning Transmission Electron Microscopy (STEM) details at the top of thick specimens can be imaged with a better resolution than those at the bottom, because the scanning electron probe is broadened by multiple scattering. For quantitative measurement we used a test specimen consisting of a substrate film with an island‐structured indium film and coated with polystyrene spheres of different diameters up to 1.1 μm. The fine detail contained in the indium film was observed and the beam broadening was that caused by the polystyrene spheres. This specimen was imaged with the spheres both above and below the layer, in a JEOL 100B electron microscope with a scanning device. Electron energies from 20 to 100 keV were used. Images with the sphere below show a higher resolution than those with the sphere above and also those of conventional electron microscopical images at 100 kV and 200 kV. The broadening of the edges on the photographic film was recorded with a microdensitometer. The results can be compared with theoretical calculations by a Monte Carlo method. There is a good agreement with the experiments if one uses an effective aperture obtained by transmission experimen

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03915.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryIn this paper an electron diffraction method is discussed by which the lattice constants of polycrystalline thin films can be accurately determined (0.1%).The method involves the sequential examination of a standard material and the unknown material mounted on separate grids. The error which can arise through the possible difference in height of the two grids can be corrected by means of height and tilting adjustments. The analytical approach of the dependence of the camera constant on the ring diameter as given in literature appears to be insufficient. An experimental correction factor for this dependence is introduced. The accuracy of this method, and the influence of relevant sources of error, are discussed and explained in terms of some experimental results.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03916.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryA technique is described for the fixation of the fowl kidney using vascular perfusion through the renal portal system. This technique should be generally applicable to avian species.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03917.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryModification of the techniques used for ultraviolet microscopy have allowed extension of the usable wavelength range down to about 220 nm. The 150 W xenon lamp in a Leitz ultraviolet microscope was replaced with a 1000 W xenon‐mercury lamp. A special low gelatin content film was employed and a new epoxy embedding medium of low UV absorbance was formulate

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1974.tb03918.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY