ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02628.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYA short history of the factors which resulted in the Cambridge Instrument Company producing the first commercial scanning electron microscope and its effects on electron microscopy today. These early machines were primarily based on the research work done in the Cambridge University Engineering Laboratories and the Cavendish Laboratory.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02629.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYAfter a brief survey of the early development of the scanning electron microscope in Germany and the U.S.A., the paper describes the work on the subject that was carried out in the Cambridge University Engineering Department, particularly in the years 1948–53. This and later work led directly to the Stereoscan SEM marketed by the Cambridge Instrument Company in 1965. The paper is illustrated with a number of micrographs produced by early scanning electron microscope

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02630.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYElectron beam fabrication studies with the scanning electron microscope began at Cambridge University in 1962. Early experiments demonstrated that structures could be made that were smaller than could be made by other methods, but it was not until several years later at IBM Research that useful devices with these smaller dimensions were made. It was even later (1981) before the resolution limits of electron beam lithography with conventional resist were measured. It is now understood that with conventional resists, electron/resist interaction effects limit the minimum structure size to about 10 nm. Newer methods that involve the direct sublimation of materials such as NaCl and LiF allow structures down to about 1 nm to be made.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02631.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYThe efficiency of a scintillator for use with a photomultiplier in a scanning electron microscope has, in the past, been specified by its detective quantum efficiency (DQE). It is shown that this is likely to give misleading results since the DQE is the product of two factors, each of which may be influenced by the properties of the photomultiplier. It is further shown that there is reason to mistrust the theoretical basis on which the measurement of DQE rests. It is suggested that a better method of specifying the merit of a scintillator/photomultiplier system is by the mean number of electrons per pulse reaching the first dynode of the photomultiplier. A description is given of the way in which this quantity, ϕ, can be determined. Results of measurements of DQE and of ϕ for three commonly used scintillators are recorde

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02632.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02633.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYSome of the early work carried out on the first scanning instrument constructed in the Cambridge University Engineering Department is recalled. The methods then used for astigmatism correction and the determination of resolving power are described and contrasted with later developments, particularly those relating to the use of on‐line digital computer technique

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02634.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYType‐1 magnetic contrast can be obtained in the secondary electron (SE) image in the SEM from a sample having an external magnetic field if the SE detector is directionally sensitive. Gauss' theorem is applied to show that the normal component of induction at the surface of the sample can be calculated from the measured spatial derivative(s) of the SE difference‐signal. A method is given in this paper for calculating the three components of the induction in the entire volume above the sample surface. Reasons are given for believing that type‐1 magnetic contrast is limited in spatial resolution by the fluxon

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02635.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYA method for the assessment of electron radiation damage to 5‐iodouracil is described which involves the use of the Patterson function. Changes in Patterson maps computed from the electron diffraction patterns recorded at increasing electron irradiation have been related to structural and chemical damage to 5‐iodouracil. The process of radiation damage is also discussed in terms of a disorder parameter which was found to increase with increasing irradiat

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02636.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SUMMARYCupromeronic Blue was used to stain selectively the proteoglycans in rat tail tendons under ‘critical electrolyte’ conditions. Earlier electron microscopical observations indicated that at least one type of proteoglycan filament is associated with tendon collagen fibrils at the positive staining band ‘d’. To ensure that this was not an artefact caused by specimen preparation or the subsequent positive staining of the collagen fibrils, we have analysed low angle meridional diffraction patterns from stained but not dehydrated, embedded or counterstained tissues. Axial electron density profiles of Cupromeronic Blue‐stained compared with unstained rat tail tendons revealed the axial locations and relative amounts of dye in both mature and young wet specimens.In mature tendons, the difference electron density profile contained a broad peak centred near residue 180 along the 234‐residue D‐period. This corresponds to the electron‐optical staining band ‘d’. In young tendons a similar distribution of stain was observed although in this case there was evidence of a doublet of peaks, one centred near residue 182 (band ‘d’) and the other near residue 165 (midway between bands d and e1).The wet proteoglycan‐Cupromeronic Blue complexes distribute over about 30 nm along the collagen fibril axis. Comparison with the images of filaments seen in the electron microscope suggests that the dye complexes collapse significantly on

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1985.tb02637.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY