Results 211 to 220 of about 69,426 (264)

Negative-Mode Soft-Tissue Xeroradiography

Radiology, 1977
Positive-mode xeroradiography is an excellent method of visualizing soft-tissue structures in mammography and other procedures; however, toner deletions over a large area may preclude adequate delineation of the soft tissues near high-density structures such as bone.
F A, Osterman, G H, Zeman, G U, Rao, B, Gayler, B G, Kirk, A E, James   +5 more
openaire   +2 more sources

Soft dipole mode in 8He

Physics of Particles and Nuclei Letters, 2009
The low-lying spectrum of 8He was studied in the 3H(6He, p)8He transfer reaction for small center of mass angles. The 0+ ground state (g.s.) of 8He and excited states, 2+ at 3.6–3.9 MeV and (1+) at 5.3–5.5 MeV, were populated with cross sections of 200, 100–250, and 90–125 μb/sr.
Grigorenko, L.V., Golovkov, M.S., Ter-Akopian, G.M., Fomichev, A.S., Oganessian, Yu.Ts., A. Gorshkov, V., Krupko, S.A., M. Rodin, A., I. Sidorchuk, S., S. Slepnev, R., V. Stepantsov, S., Wolski, R., Y. Pang, D., Chudoba, V., Korsheninnikov, A.A., A. Kuzmin, E., Nikolskii, E.Yu., Novatskii, B.G., Stepanov, D.N., Roussel-Chomaz, P., Mittig, W., Ninane, A., Hanappe, F., Stuttgé, L., Yukhimchuk, A.A., Perevozchikov, V.V., Vinogradov, Yu.I., K. Grishechkin, S., Zlatoustovskiy, S.V.   +28 more
openaire   +2 more sources

Soft modes in betaines

Ferroelectrics, 1988
Abstract Betainea are a new family of crystals including ferroelectric, antiferroelectric and incommensurate crystals /1–3/. We have used submillimeter backward wave oscillator spectroscopy /4/ to investigate the dynamical properties of betainearsenate (BA), deuterated BA (DBA), betainephosphate (BP) and betainecalciumchloride (BCC) at the frequencies ...
Yu. G. Goncharov, G. V. Kozlov, A. A. Volkov, J. Albers, J. Petzelt   +4 more
openaire   +1 more source

Charge density glass dynamics – Soft potentials and soft modes

Physica B: Condensed Matter, 2012
An universal fingerprint of glasses has been found in low-temperature thermodynamic properties of charge/spin density wave (C/SDW) systems. Deviations from the well-known Debye, elastic continuum prediction for specific heat (flat Cp/T3 plot) appear as two anomalies ; the upturn below 1 K and a broad bump at T~10 K (named Boson peak in glasses).
Biljaković, K., Staresinic, D., Lasjaunias, Jean-Claude, Remenyi, Gyorgy, Melin, Régis, Monceau, Pierre, Sahling, S.   +6 more
openaire   +4 more sources

Soft phonon mode and mode coupling in SbSI

Solid State Communications, 1970
Abstract In ferroelectric SbSI the soft mode behaviour is studied by means of Raman scattering. It is observed that coupling occurs between the soft mode and a lower-frequency mode which leads to level repulsion between the two Γ 1 one-phonon states and intensity between the modes.
G. Harbeke, E.F. Steigmeier, R.K. Wehner
openaire   +1 more source

Soft Modes and Mode Splitting in Paramagnetic TbP§

1980
In contrast to spin-only systems the paramagnetic phases of systems with crystal field split ground multiplets exhibit magnetic excitations of finite energy. In the presence of a magnetic exchange coupling the excitons will propagate through the lattice. A measurement of the dispersion allows in principle an insight into the exchange interaction, which
Knorr, K., Loidl, Alois, Kjems, J. K.
openaire   +2 more sources

Soft mode behavior in RbH2AsO4

Physics Letters A, 1973
Abstract The low frequency xy Raman spectra of RbH2AsO4 are reported as a function of temperature in the paraelectric phase and are fitted to a coupled damped harmonic oscillator model to yield the soft mode behavior of the ferroelectric model.
R.C. Leung, R.P. Lowndes, N.E. Tornberg
openaire   +1 more source

Phase Transitions and Soft Modes

Physical Review A, 1972
The stability of an equilibrium phase is described in thermodynamics in terms of certain convexity properties of the free energy. The phase is said to be unstable with respect to an equilibrium phase transition if the isothermal response of the system to a static external field is infinite. It is also known that associated with several second-order and
T. Schneider, G. Srinivasan, C. P. Enz
openaire   +1 more source

The soft-mode ferroelectric effect

Ferroelectrics, 1988
Abstract In this paper a presentation is given of some of the basic physics of the soft-mode ferroelectric effect, along with its experimental background. Further, possible applications in electrooptic devices are elucidated. A fast (sub-microsecond) electrooptic switching can be achieved in the A* phase, and in similar orthogonal smectic phases made ...
G. Andersson, I. Dahl, W. Kuczynski, S. T. Lagerwall, K. Skarp, B. Stebler   +5 more
openaire   +1 more source

Soft modes in ferroelectric superlattices

Ferroelectrics, 1990
Abstract A phenomenological theory of periodic ferroelectric multilayers, consisting of two alternating ferroelectrics with different transition temperatures, is presented. We consider the case of a ferroelectric phase transition of first order. Interface modes are shown to exist, resulting from the special form of the inhomogeneous polarization ...
D. Schwenk, F. Fishman, F. Schwabl
openaire   +1 more source