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