Bose-Einstein correlations in e+e− annihilation in the γ(1S) and continuum

Bose-Einstein correlations in direct γ(1S) decays and continuum in the energy region √s=7.2?10.3 GeV have been studied using data taken with the MD-1 detector at VEPP-4 storage ring. Assuming gaussian density of the pion source the data indicate the radius of the sourceπ=0.73±0.10±0.04 fm for direct γ (1S) decays andπ=0.83±0.22±0.05 fm for the continuum. The correlation strengthsλ for both data samples also are similar. Thus Bose-Einstein correlations do not reveal a noticeable difference between quark and gluon fragmentation.     

Analytic investigation of the stress-strain relation for an arbitrary loading trajectory

The determination of the strain trajectory from a known arbitrary loading trajectory is described within the framework of the theory of slip. Specific calculations have been made on an electronic computer.Institute of Physics and Mathematics, Academy of Sciences of the Kirgiz SSR, Frunze. Translated from Mekhanika Polimerov, No. 6, pp. 981–986, November–December, 1971.     

Dielectric properties of antiferroelectric liquid crystals composed of banana-like molecules

The dielectric properties of an antiferroelectric B₂ phase representing a homolog (n=14) from a series of 4-chloro-1,3-phenylene-bis[4-(4-n-alkylphenyl)aminobenzoates] with banana-like molecules were studied. The temperature dependence of the dielectric relaxation time was measured, and the corresponding activation energy was determined. The kinetics of the dielectric permittivity was studied in the course of the polarization vector variation under the action of a low-slope triangular bias voltage in the entire temperature range of existence of the B₂ phase. Dependence of the dielectric permittivity on the electric field strength (bias voltage) is determined by the presence of two polar subsystems forming the antiferroelectric B₂ phase.     

Structural transformations in high-nitrogen austenitic steel

Results are reported from a study of the structure of steel aged after quenching and subsequent rolling at 20, 400, and 1000°C. It is shown that cold and warm rolling with low and moderate degrees of deformation intensifies the reaction which results in the discontinuous precipitation of chromium nitride. With high degrees of deformation, this reaction does not take place, and heterogeneous precipitation of nitrides occurs. Discontinuous and heterogeneous nitride precipitation take place during hot rolling. During subsequent aging, the processes of spheroidization, coalescence, and recrystallization result in the formation of a microduplex structure.Deceased.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 32–36, June, 1988.     

Search for ξ(2.2) andX(2.2) in radiative decays of ϒ-meson

The results of an experiment on the search for ξ(2.2) andX(2.2) in the radiative decays of the Υ-meson are presented. The experiment was carried out with the MD-1 detector at the VEPP-4 collider. An upper limitB(Υ→γξ)B(ξ→K ⁺ K ^?)<2·10^?4 is obtained at 90% C.L. Results are presented on the search for the decay Υ→γX, X→ ?? not previously investigated. For this decay the upper limitB(Υ→γX)B(X→??)<3·10^?3 is obtained at 90% C.L.     

Study of adhesion of vertically aligned carbon nanotubes to a substrate by atomic-force microscopy

The adhesion to a substrate of vertically aligned carbon nanotubes (VA CNT) produced by plasmaenhanced chemical vapor deposition has been experimentally studied by atomic-force microscopy in the current spectroscopy mode. The longitudinal deformation of VA CNT by applying an external electric field has been simulated. Based on the results, a technique of determining VA CNT adhesion to a substrate has been developed that is used to measure the adhesion strength of connecting VA CNT to a substrate. The adhesion to a substrate of VA CNT 70–120 nm in diameter varies from 0.55 to 1.19 mJ/m², and the adhesion force from 92.5 to 226.1 nN. When applying a mechanical load, the adhesion strength of the connecting VA CNT to a substrate is 714.1 ± 138.4 MPa, and the corresponding detachment force increases from 1.93 to 10.33 μN with an increase in the VA CNT diameter. As an external electric field is applied, the adhesion strength is almost doubled and is 1.43 ± 0.29 GPa, and the corresponding detachment force is changed from 3.83 to 20.02 μN. The results can be used in the design of technological processes of formation of emission structures, VA CNT-based elements for vacuum microelectronics and micro- and nanosystem engineering, and also the methods of probe nanodiagnostics of VA CNT.     

Light transmission coefficients by subwavelength aluminum gratings with dielectric layers

Spectral positions of plasmon resonances related to boundaries between a thin aluminum layer and dielectrics (air, glass, VDF–TrFE 65/35 ferroelectric copolymer, and indium tin oxide (ITO)) have been determined in the transmission spectra of aluminum gratings of three types with 30 × 30 μm² dimensions and 350-, 400-, and 450-nm line periods. Experimental results agree well with spectral positions of plasmon resonances calculated for the normal incidence of TM-polarized light. In addition, maximum values of transmission coefficients in the region of λ ≈ 900–950 nm have been determined for glass–Al–copolymer and glass–ITO–Al–copolymer structures. These values are close to 100%, which shows that the effective optical aperture is two times greater than the geometric areas of slits.     

Global controllability of conditionally periodic linear system

We use the notation: Rⁿ Is n-dimensional Euclidean space;S _a (x⁰)={x Rⁿ: ¦x-x ⁰ ¦ }; int Q is the interior of setQ Rⁿ. With any linear systemx=A (t)x +B (t) u, x Rⁿ,u R^m, (1)Translated from Matematicheskie Zametki, Vol. 32, No. 2, pp. 169–174, August, 1982.