Fe-containing nanoparticles on the surface of silica microgranules

We have prepared nanomaterials consisting of SiO₂ microgranules and Fe-containing nanoparticles on their surface and determined the size and composition of the nanoparticles. The nanoparticles are shown to have a core-shell structure (α-Fe core and γ-Fe₂O₃ shell). The α-Fe core and Fe₂O₃ shell are responsible, respectively, for the broad and narrow lines in the EMR spectrum of the nanoparticles. The magnetic properties of larger nanoparticles are dominated by the core, while those of smaller nanoparticles are dominated by the oxide shell.     

Spark ignition of atomized liquid fuel

Tomsk. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 1, pp. 11–15, January–February, 1990.     

Microwave-band reflection coefficient of high-temperature superconductor specimens in E-plane waveguide structures

The microwave-band reflectivity of high-temperature superconductor (HTSC) specimens was measured for the first time in the E-plane waveguide structures of two types: tapered waveguide termination and E-plane corner section. The measured reflection coefficient of a textured YBa₂Cu₃O_7−δ specimen used as a tapered waveguide termination corresponds well to the theoretical curve calculated using an improved two-fluid HTSC model.     

Comparison of the frequency of a He-Ne laser stabilized to the central component of the magnetic hyperfine structure of the F2 (2) line of methane

Translated from Izmeritel'naya Tekhnika, No. 4, pp. 18–20, April, 1989.     

Copper Nanoparticles in a Polyethylene Matrix

The composition and structure of Cu-containing nanoparticles stabilized in a polyethylene matrix were studied. The nearest neighbor environment of Cu in the 15-nm particles is similar to that in metallic Cu. In contrast to Fe nanoparticles, the Cu nanoparticles embedded in polyethylene do not oxidize during storage in air.     

Parameters of air shock waves when combustion is transformed into detonation

Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 25, No. 5, pp. 111–115, September–October, 1989.     

Recirculation fiber loop interferometer with a Faraday reflector

A new optical scheme of the recirculation fiber loop interferometer with a Faraday reflector and a broadband radiation source is suggested. It is experimentally established that this scheme provides for a more than tenfold decrease in the instrument zero response caused by a spurious polarization modulation in the phase modulator. Factors leading to additional shifts in the instrument zero response are revealed.     

Accuracy of the computer-controlled laser frequency standards basedon resolved hyperfine structure of a methane line

Results of 2-year frequency comparisons of our transportable He-Ne laser standard stabilized on a component of the magnetic hyperfine structure (MHFS) of the F₂² line of methane λ=3.39 μm, with our stationary laser using resolved recoil doubler as reference are presented. The absolute frequency of the transportable laser measured at PTB (Physikalisch-Technische Bundesanstalt, Braunschweig, Germany), using the radio-optical frequency chain, was transferred to the stationary device. On the basis of the theoretical model of the line shape, the frequency of unperturbed transition has peen calculated     

Reconstructive operations on the head and neck using a microsurgical technic

Eighty-one patients with defects and deformations of the head and neck of various origin were examined and treated. Microsurgical autotransplantation of vascularized tissue complexes was carried out in all the cases. Profound preliminary examinations of patients helped objectively define the indications for the use of this method. Special attention was paid to the choice of donor zone. Due to correct selection of a complex graft, good functional and cosmetic results were attained. Despite repeated corrective operations in 16 patients, virtually complete social and communal rehabilitation was attained in 74 (91.4%) patients by using a limited number of donor areas. The authors persuasively demonstrate the advantages of microsurgery in repair of complex and extensive defects on the head and neck.     

Nonsteady-state interaction of a combustion wave with a dust cloud

A mathematical model of inhibition of gas flames by inert powders is studied.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 55, No. 2, pp. 236–243, August, 1988.