Articles you may be interested inMetrological large range scanning probe microscope Rev. Sci. Instrum. 75, 962 (2004); 10.1063/1.1651638 Quantitative method of image analysis when drift is present in a scanning probe microscope Scanning probe microscopy ͑SPM͒ is used widely for the characterization of topographic structure in both material and bio-sciences. However, due to the finite size of the imaging tip, the SPM may not record all of the surface. Dimensional measurements made on such surfaces will not reflect the true nature of the surface. Simulated images have been used to assess the effects of imaging and image reconstruction methods on surface roughness and dimensional measurements. A novel combination of image reconstruction techniques and connectivity criteria is used to set bounds on the certainty of dimensional and topographic measures and to obtain more information about the spatial complexity of the sample surface. A more complete description of the sample is obtained without prior knowledge of the sample or tip geometry.

spond to very weak complexes. Also, given the excellent correlation between the 'ß and the electrostatic energy parameters (<5Z) of the aromatic solutes (Figure 1), it seems unlikely that charge-transfer forces are important. If they were, one would expect a trend of increasing with increasing methylation of the aromatic ring (or decreasing "donor" ionization potential), which is not observed. Note the low value for mesitylene and the high values for the balobenzenes in Table IV. It is concluded, therefore, that the interactions present in these systems, whether they lead to long-lived complexes or short-lived contact interactions,23 are predominantly electrostatic in nature.Supplementary Material Available. Tables VI-IX will appear following these pages in the microfilm edition of this volume of the journal. These tables contain specific retention volumes (Vg°), infinite dilution activity coefficients (72" ), and interaction parameters ( ) at 30, 40, 50, and 60°for the 48 binary systems found in Table III. Photocopies of the supplementary material from this paper only or microfiche (105 X 148 mm, 24X reduction, negatives) containing all of the supplementary material for the papers in this issue may be obtained from the Journals Department, American Chemical Society, 1155 16th St.,

An understanding of the scattering of an electron beam as it passes through a volume of low pressure gas is of critical importance for users of Low Vacuum and Environmental Scanning Electron Microscopes (LV-SEM & ESEM respectively) The ‘skirting’ of the primary beam as a result of scattering is of particular importance in X-ray microanalysis where scattered electrons, falling onto the sample away from the probe beam, can adversely affect the spatial resolution of the X-ray signal. A number of studies have attempted to quantify the width of the probe beam experimentally and hence determine optimum microscope operating parameters. Theoretical and computational work modelling the interactions of the beam with the gas have suggested that the shape of the probe beam can be modelled by some form of Gaussian. Experimental measurements, however, suggest that the probe has a skirted form rather than a Gaussian one.

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