| Abbe's law of limiting resolution | <physics> For a periodic structure of units separated by distance d and obliquely illuminated by the unrefracted ray and one of the two diffracted rays (extremely oblique illumination). Abbe applied the law of diffraction: d = 0.5 lambda /NA, where: lambda = wavelength of the monochromic light or shortest of mixed wavelengths NA = the limiting numerical aperture (NA) of objective or condenser. (05 Aug 1998) |
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| resolution | Complete return to normal structure and function: used, for example: of an inflammatory lesion or of a disease. (18 Nov 1997) |
| resolution acuity | The detection of a target having two or more parts, often measured by using the Snellen test types; indicated by two numbers: the first represents the distance at which an individual sees the test types (usually 6 meters or 20 feet), and the second, the distance at which the test types subtend an angle of 5 minutes; e.g., vision of 6/9 indicates a test distance of 6 meters and recognition of symbols which subtend an angle of 5 minutes at a distance of 9 meters. Synonym: visual acuity. (05 Mar 2000) |
| high-resolution banding | Banding, especially in prophase, which increases the clarity and number of discernible chromosome bands. (05 Mar 2000) |
| high resolution computed tomography | Computed tomography with narrow collimation to reduce volume-averaging and an edge-enhancing reconstruction algorithm to sharpen the image, sometimes with a restricted field of view to minimise the size of pixels in the region imaged; used particularly for lung imaging. Hypocycloidal tomography, body section radiography using a complex film and tube motion with a pattern resembling a three-leaf clover. (05 Mar 2000) |
| high-resolution imaging | <technique> High Resolution Electron Microscopy is phase contrast microscopy of the atomic structure of materials. In most crystalline inorganic materials and a number of polymeric materials HREM allows the imaging of individual atomic columns. The images can frequently be interpreted in terms of the projected crystal potential, although it is often necessary to match the experimental images with those calculated from multislice algorithms. Allows direct measurement of lattice parameters, inspection of individual defects and grain orientation. (05 Aug 1998) |
| limit of resolution | 1. <optics> The resolution of an optical system defines the closest proximity of two objects that can be seen as two distinct regions of the image. This limit depends upon the Numerical Aperture of the optical system, the contrast step between objects and background and the shape of the objects. The often quoted Airy limit applies only to self luminous discs. 2. <genetics> The smallest map distance measurable by an experiment involving a certain number of classified recombinant progency. (10 Mar 1998) |
| activation energy | <chemistry> The amount of energy (expressed in joules) that is needed to convert all the molecules in one mole of a reacting substance from a ground state to the transition state. (06 May 1997) |
| binding energy | <chemistry, radiobiology> The binding energy of a nucleus is the minimum energy required to dissociate it into its component neutrons and protons. Neutron or proton binding energies are those required to remove a neutron or proton, respectively, from a nucleus. Electron binding energy is that required to remove an electron from an atom or a molecule. (16 Dec 1997) |
| bioelectric energy sources | Implantable devices which convert biological energy (chemical energy of the metabolism of continuously regenerating body fluids or mechanical energy of periodic movements) to electrical energy. The sources include biogalvanic cells, biofuel cells, and ionic concentration cells. (12 Dec 1998) |
| biomass energy | See Bioenergy. (05 Dec 1998) |
| bond dissociation energy | This is the energy needed to break the bonds between two linked atoms. (09 Oct 1997) |
| bond energy | The energy needed to break a molecular bond. (09 Oct 1997) |
| radiant energy | Energy contained in light rays or any other form of radiation. (05 Mar 2000) |
| radiography, dual-energy scanned projection | A method of producing a high-quality scan by digitizing and subtracting the images produced by high- and low-energy X-rays. (12 Dec 1998) |