Johansson crystal

A. I. Abrikosov, P. James, O. Eriksson, P. Soderlind, A. V. Ruban, H. L. Skriver, and B. Johansson, Magnetically induced crystal structure and phase stability in FecCoi c, Phys. Rev. B (to be published). 

With x-rays, however, one can have his cake and eat it too That the two conditions given above can both be met for a curved crystal was - appreciated first by Du Mond and Kirkpatrick18 and put into practice first by Johansson.21 This situation exists because-the crystal is a three-dimensional lattice of exceedingly small spacing. It is therefore possible to bend the crystal until the Bragg planes have the radius R,... 

The Johansson arrangement is clearly to be preferred over the two others when a suitable crystal is available. 

Fig. 4-13. Bent arid ground crystal spectrograph. (Johansson). The x-rays make the same angle with the crystal planes as in Fig. 4 12, but the grinding has brought these planes to lie on the focal circle.

Johansson, K., El-Ahmad, M., Friemann, R., Jomvall, H., Markovic, O., and Eklund, H. (2002). Crystal structure of plant pectin methylesterase. FEBS Lett. 514, 243-249. 

Svensson, S., Oestberg, T., Jacobsson, M., Norstroem, C., Stefansson, K., Hallen, D., Johansson, I.C., Zachrisson, K., Ogg, D. and Jendeberg, L. (2003) Crystal structure of the heterodimeric complex of LXRa and RXRP ligand-binding domains in a fully agonistic conformation. The EM BO Journal, 22, 4625-4633. 

Many hypotheses for initiation of liquid expls have been proposed, of which Bowden et al (Refs 13, 14a 27) suggested adiabatic compression of gas bubbles Johansson et al (Ref 28) - vapor or droplet burning Andreev (Ref 29) - droplet formation or suspension behind a burning front is capable of causing a transition to detonation Bolkhovitinov (Ref 33a) - crystallization of the material under pressure Cook et al (Ref 34b) - initiation occurs with the development of a pressure-generated metallic state accompanied by a plasma that provides the postulated requirement of high heat conductivity... 

An optical diagram of a Johansson curved-crystal spectrometer is given in Fig 9. F.ach spectrometer of an x-ray qnantometer may be equipped with optimum crystal-detector combinations for specific determinations in a wide variety of matrixes, including steel, aluminum, copper-base materials, ores, cement, and slags—in both liquid and solid states. 

Fig. 9. Optical diagram of Johansson curved-crystal spectrometer...

Nyman, T., Stenmark, P., Flodin, S., Johansson, I., Hammarstrom, M., Nordlund, P. The crystal structure of the human toll-like receptor 10 cytoplasmic domain reveals a putative signaling dimer. J Biol Chem 283 (2008) 11861-11865. 

Johansson and co-workers (7, 8, 9) have shown that heat transfer from a compressed spherical bubble does not increase the temperature of its liquid surface sufficiently to account for the impact sensitivity of liquid explosives the high sensitivity of nitroglycerin is postulated as arising from the fact that small droplets are readily formed by the impact and ignited by the compressed air. Bolkhovitinov (1) postulated crystallization of the liquid under the impact pressure, with the phase transition causing the temperature increase which causes explosions. Bowden (3) favors the adiabatic compression of gas bubbles combined with the dispersion of the explosive into fine particles as the mechanism for initiation by mechanical impact. 

Johansson G (1962c) On the crystal stracture of the basic aluminum selenate. Arkiv. Kemi 20 305-319 Johansson G, Lundgren G, Sillen LG, Soderquist R (1960) On the crystal stracture of a basic aluminum sulfate and the corresponding selenate. Acta Chem Scand 14 769-771 Jolivet J-P (1994) De la Solution a I Oxyde, 3rd ed, Masson, Paris... 

Figure 2.13. Diagram showing how a Johansson curved crystal monochromator works...

On the basis of these comparative studies, the thermodynamics of Am appears to be well-established, the heat of vaporization reported in Ref. 10 being confirmed. It should be noted that the crystal entropy estimate for Am was based on La as a model. In terms of the rare-earth/actinide pairing of Johansson discussed earlier, the entropy for Pr with the magnetic contribution removed would have given a similar result. 

Recently, Izawa et al. studied the chemical effect of the L /L. X-ray intensity ratio of molybdenum compounds by electron and proton bombardment. The X-ray spectra were measured with a curved crystal spectrometer (Johansson type, ADP crystal). and are representative of variable and invariable peaks, respectively. 

All3 solutions are known to produce different types of sulfate crystal structures depending on pH (Johansson 1960 Johansson 1963). Our studies showed that the AI13 solutions tend to crystallize in the form of the monoclinic... 

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