Microscopes simple

M. Schick, W. H. Shih. Simple microscopic model of a microemulsion. Phys Rev Lett 59 1205-1208, 1987. 

In 1665, Robert Hooke examined thin slices of cork under his very simple microscope and discovered small, box-like spaces which he named cells. A few years later the Italian anatomist Marcello Malpighi described similar structures in animal tissues, which he called vesicles or utricles and, in 1672, the English botanist Nehemiah Grew published two extensively illustrated volumes greatly extending Hooke s findings. The concept of the cell as a unit of structure in the plant and animal kingdoms was launched, but it was two centuries later before scientists... 

When we see an object, light rays bounce off (are diffracted by) the object and enter the eye through the lens, which reconstructs an image of the object and focuses it on the retina. In a simple microscope, an illuminated object is placed just beyond one focal point of a lens, which is called the objective lens. The lens collects light diffracted from the object and reconstructs an image beyond the focal point on the opposite side of the lens, as shown in Fig. 2.1. 

The study of oxygen diffusion in oxides with mixed-valence 3d-ions presents great interest both in theoretical and practical terms. Such systems with Jahn-Teller (JT) 3d-cations are suitable model objects for analysis of the diffusion process in degenerate or pseudo-degenerate condensed systems. The mechanism of multi-well potential formation has been explored well for JT ions [1,2] and it is possible to give a simple microscopic description of the inter-center interactions and different properties of these systems. The practical interest paid to diffusion properties of the... 

The field vole, Microtus oeconomus, has X and Y chromosomes with unique patterns of heterochromatin, which means that they can easily be identified in spermatids. Thus, by simple microscopic examination of testes, spermatids with XX, XY, YY, or no sex chromosome can be identified (the latter with less certainty because a poorly stained cell can mimic one without sex chromosomes). Diploid spermatids can be identified not only on the basis of their two sex chromosomes, but also because they are large cells. 

Antonie van Leeuwenhoek (1632-1723), draper of Delft in Holland, ground his own lenses and made simple microscopes that gave magnifications of x200. On October 9. 1676, he sent a 17 / -page letter to the Royal Society of London, in which he described animalcules in various water samples. These small organisms included what are today known as protozoans and bacteria thus Leeuwenhoek is credited with the first observation of bacteria. Later work of his included the identification of spermatozoa and red blood cells from many species. 

The method used consisted in measnsng the distance from the radium at which the salt, exposed on a tray of black paper, became distinctly visible in the dark. The salt was observed by means of a simple microscope fixed over the tray, and the intensity of the rays was taken to be inversely as the square of the distance between, the radium and the salt. 

Baranova et al. were the first to present a simple microscopic model [10] that can give an order-of-magnitude estimate for MChA. It is an extension of the classical Becquerel model for MOA [13], and it interprets MChA as a result of the Larmor precession in NO A. Baranova et al. find (CGS units)... 

This consists simply of a convex lens or several combined into a system and appropriately mounted. A good example of a simple microscope is a reading glass. This type of simple microscope is valuable in field work, in the examination of dried herbarium material or the external characters of crude drugs, where only a low magnification of the object is required. 

However a simple microscope may also be used given a degree of simple improvization. Obtain some polaroid sheet and secure a piece beneath the stage between the sample slide and light source (or reflecting mirror) as indicated in the Figure. 

Theoretical studies were performed for Using a simple microscopic theory 2 is correlated to direct interband transitions. C2((o) can be calculated using a simple approach from the joint density of states J (to), see below. 2(0)) is then ... 

In the 1930s, Chamot and Mason defined the state of chemical microscopy (6) by detailing their work on the physical methods and chemical analysis involved with chemical microscopy. In the U.K. in 1954, Welch described a simple microscope attachment for the observation of high-temperature phenomena (7). The small, electrically heated thermocouple could hold a microscopic sample for single-crystal growth assays, melting-point determinations, and glass devitrification studies. 

In P. falciparum infections, the disappearance of parasitized red cells from the peripheral circulation (as evidenced by simple microscopic examination of a blood film) may be followed by a re-appearance of parasites in... 

The applicability of donicities to cation-solvent interactions is most convincingly demonstrated by the polarographic reduction of various metal ions in solvents of different donicity. The observed variation of half-wave potentials with solvent donicity can be explained neither in terms of the Born equation nor by simple microscopic electrostatic models in view of the magnitude of the dipole moments of solvent molecules. The concept also provides the basis for an interpretation of complex formation reactions and the behaviour of electrolytes (ion pair equilibria) in a large number of EPD solvents. 

Anemia is an excellent example of how complex interpretation of findings can be. Often, the first assumption made when treatment-related anemia is observed is that the drug being tested is a bone marrow toxin. Evaluating this possibihty can be relatively straightforward. Examination of the bone marrow, usually by simple microscopic examination of smears, can give a clue that... 

M. H. Muser, L. Wenning, and M. O. Robbins, Simple microscopic theory of Amontons s laws for static friction. Phys. Rev. Lett, 86, 1295 (2001). 

Schick M and Shih W-H 1987 Simple microscopic model of a microemulsion Phys. Rev. Lett. 59 1205... 

Optically driven photon correlation experiments normally require confining the detection or the excitation to an extremely small sample volume. This is achieved either by confocal detection or two-photon excitation in a microscope. The optical principles are the same as in confocal and two-photon laser scanning microscopes (see Sect. 5.7, page 129). However, most correlation experiments do not require scanning and can be performed in relatively simple microscopes. 

We have also seen that there are strong similarities between systems containing small amphiphilic molecules on the one hand and diblock copolymers on the other. In both cases, the amphiphiles contain within themselves the properties of the components of two mutually insoluble liquids. The theory of diblock copolymers is more advanced than that of the small molecular systems not only because a simple microscopic model describes most properties of the polymers very well, but also because these properties depend on large-scale behavior of the chains, not small-scale behavior of the monomers. Furthermore, the large polymerization index guarantees that thermal fluctuations are less important than in small molecular systems, so that mean-field theories give very reliable results. 

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