23 research outputs found
Scaling properties of the critical behavior in the dilute antiferromagnet Fe(0.93)Zn(0.07)F2
Critical scattering analyses for dilute antiferromagnets are made difficult
by the lack of predicted theoretical line shapes beyond mean-field models.
Nevertheless, with the use of some general scaling assumptions we have
developed a procedure by which we can analyze the equilibrium critical
scattering in these systems for H=0, the random-exchange Ising model, and, more
importantly, for H>0, the random-field Ising model. Our new fitting approach,
as opposed to the more conventional techniques, allows us to obtain the
universal critical behavior exponents and amplitude ratios as well as the
critical line shapes. We discuss the technique as applied to
Fe(0.93)Zn(0.07)F2. The general technique, however, should be applicable to
other problems where the scattering line shapes are not well understood but
scaling is expected to hold.Comment: 17 pages, 5 figure
Ordering in the dilute weakly-anisotropic antiferromagnet Mn(0.35)Zn(0.65)F2
The highly diluted antiferromagnet Mn(0.35)Zn(0.65)F2 has been investigated
by neutron scattering in zero field. The Bragg peaks observed below the Neel
temperature TN (approximately 10.9 K) indicate stable antiferromagnetic
long-range ordering at low temperature. The critical behavior is governed by
random-exchange Ising model critical exponents (nu approximately 0.69 and gamma
approximately 1.31), as reported for Mn(x)Zn(1-x)F2 with higher x and for the
isostructural compound Fe(x)Zn(1-x)F2. However, in addition to the Bragg peaks,
unusual scattering behavior appears for |q|>0 below a glassy temperature Tg
approximately 7.0 K. The glassy region T<Tg corresponds to that of noticeable
frequency dependence in earlier zero-field ac susceptibility measurements on
this sample. These results indicate that long-range order coexists with
short-range nonequilibrium clusters in this highly diluted magnet.Comment: 7 pages, 5 figure
Оценка проб выдыхаемого воздуха методом лазерной оптико-акустической спектроскопии у больных туберкулезом легких
Absorption spectra of breath air for 108 healthy persons, 28 patients with pulmonary tuberculosis and 56 patients with many a diseases were recorded using laser photoacoustic technique. It was ascertained that, as the breath air analysis result, pulmonary tuberculosis can be diagnosed.Методом лазерной оптико-акустической спектроскопии были получены спектры поглощения проб выдыхаемого воздуха 108 здоровых доноров, 28 пациентов с туберкулезом легких и 56 пациентов с другими заболеваниями. Проведенный анализ показал, что во многих случаях по результатам обработки спектров проб выдыхаемого воздуха можно установить наличие или отсутствие у пациента туберкулеза легких
State evaluation of the oral cavity microflora based on Laser optical-acoustic spectroscopy
Owing to shortcomings of existing methods of evaluation of oral cavity microflora, reviewed possibilities for this purpose of new noninvasive method — laser optical-acoustic spectroscopy. The results show perspectivities of this method for diagnosis of microflora disorders