ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04665.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYThe technique of combined electron microscopy and energy analysis is described, together with the main energy loss process that is used to analyse composition. It is shown that the spatial resolution of the technique is ∼ 14 nm which is ten times better than any other technique available at present. The composition resolution in aluminium alloys is<1 at.%, the exact value depends upon which alloy system is used.Applications of the technique to the measurement of fine scale concentration gradients are described for Al‐Cu, Al‐Mg and Al‐Zn‐

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04666.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYDetailed analysis of thin oxide films is providing a better understanding of the mechanisms of oxidation and corrosion. The analytical electron microscope used to study thin layers on iron‐chromium alloys has shown that even after oxidation times as short as 10 min at 600°C the ratio of iron to chromium in the surface oxide will be different from that in the underlying alloy and discrete nodules may well have a higher iron content than the protective film in which they are growing. Progressive changes in different morphological features of the oxide films grown at varying times and temperatures can be followed by micro‐probe analysis in EMMA 4. Results obtained from the oxidation in air of iron with 10% and iron with 20% added chromium are prese

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04667.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYResults are reported concerning the application of the analytical electron microscope EMMA‐4 to the quantitative analysis of thin foils. A simple procedure by which the observed characteristic X‐ray intensities from a thin foil sample can be converted into chemical weight fractions is described. This technique has been applied to study the partitioning of manganese between the carbide and ferrite phases during the isothermal decomposition of a eutectoid steel. The results show that it is possible to analyse the manganese content of the ferrite and carbide phases independently and the partitioning of manganese to the carbide phase has been followed as a function of time at the isothermal transformation temperature.The analysis of a calcium‐rich pyroxene which contains calcium‐poor precipitate lamellae is described. The results are consistent with the precipitation of a pigeonite, poor in calcium and rich in iron, from an augite host.The third example is the‘in situ’analysis of nitride precipitates in a stainless steel. The precipitates are known to contain either titanium or chromium, but it is impossible from morphological or diffraction evidence to differentiate between the two types of nitride. Combined electron microscopy and microprobe analysis is shown to be a rapid and positive means of identifying the p

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04668.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYSome metallurgical studies carried out using a combined electron microscope — microanalyser (EMMA‐3) are described. A correction procedure is outlined for the quantitative X‐ray microanalysis of thin foils and small extracted particles. The applications discussed include (a) the examination of small crystals of carbides and spinel‐type oxides, (b) the analysis of small, single‐phase grains in splat‐quenched Al‐8%Fe, and (c) the identification of small ferrite grains within an austenite matrix by means of the convergent‐beam diffra

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04669.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYThe quantitative X‐ray microanalysis of ultrathin biological sections is exemplified by a recent study of the distribution of calcium in mineralizing cartilage and bone. The determination of calcium mass‐fraction in one microarea of a vesicle within a section of rabbit epiphyseal plate cartilage is presented in detail in order to display all steps of the processing of the data. Mass fractions are obtained from an equation which is approximate but which is adequately accurate for most cases of interest, specifically for ultrathin biological sections where the analysed area consists predominantly of organic matrix. We shall examine the physical assumptions behind the computation, and the extent to which these assumptions have been verified in the analytical microscope.The purpose of this paper is to describe in detail the scheme of data collection and processing, which has now been in use for some years in the Cavendish Laboratory, for the measurement of local elemental mass fractions in thin biological specimens in instruments like the EMMA. After an outline of the physical theory we shall describe the handling of the data by means of working through an example of an actual measurement, and finally we shall add some comments, mainly precautions and reservati

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04670.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYA routine method is described for X‐ray microanalysis of thin specimens of biological tissue containing mineral particles in cancerous growths. Such a method allows information to be obtained that relates pathological history to histology, electron microscopy and X‐ray microanalysis.Classification of minerals is possible in a way that is not provided by bulk analysis.The technique provides baselines of elemental data of minerals from various sources that may be used to classify particles found present in certain tumour grow

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04671.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYThe possibility of using sections obtained by cryo‐ultramicrotomy in the study of the fine structure of myofilaments was explored. Heart and skeletal muscles were stabilized for 5–15 min in 2.5% glutaraldehyde. Neither cryo‐protection, encapsulation nor any other chemical treatment preceded the freezing in Freon‐12 cooled by liquid nitrogen. ‘Wet’ sectioning was performed using dimethyl sulphoxide (50% in water) in the knife trough. The sections were stained using either positive or negative contrasting techniques.The results showed that sections prepared by cryo‐ultramicrotomy permit high resolution studies, especially if negatively stained. By eliminating several steps of specimen preparation that destroy the native configuration of biopolymers, the method promises to make it possible to study well‐preserved myofilaments and their fine structure, both in longitudinal and cross‐section,in situ. It is not yet certain, however, that new sources of artefacts a

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04672.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYUltrathin frozen sections of glutaraldehyde fixed yeast cells have been successfully used for the demonstration of acid and alkaline phosphatase.Acid phosphatase was localized over the cell wall of both the mother cell and the bud as well as over the newly forming cross wall (septum). Cytoplasmic vesicles (vacuoles, lysosomes?) located close to the cell wall showed a positive reaction for acid phosphatase as well. After 3 h glutaraldehyde fixation an activation of the nuclear acid phosphatase was observed. Lead precipitates were predominantly found over the nucleolar material of ‘resting’ and budding cells.Alkaline phosphatase could be demonstrated in the ‘yeast‐mesosome’ and within the plasmalemma invaginations. After separation of the bud, small vesicles, probably derived from the endoplasmic reticulum showed a strong positive reaction for alkaline phosphatase.In frozen sections incubated for alkaline phosphatase, non‐specific lead precipitates were found in the nucleus and along the plasmalemma in

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04673.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

SUMMARYUltrathin frozen sections have been obtained from single cells both in the fixed and native state. For fixed material a rapid method is described which yields excellent structural preservation. The preparation is based on brief treatment with glutaraldehyde, polyvinylpyrrolidone and ‘encapsulation’ in gelatin. Ultra‐thin frozen sections prepared after this technique seem to be especially suitable for cytochemical work. Unfixed testis has been also cut with a dry knife. The contrast in this completely untreated section is sufficient to discern the different parts of sperma

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1973.tb04674.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY