Plasma-Enhanced Chemical Vapor Deposition of Silicon Carbonitride Films from Volatile Silyl Derivatives of 1,1-Dimethylhydrazine

Silicon carbonitride films were synthesized from new volatile precursors by plasma-enhanced chemical vapor deposition. Based on a detailed study of the morphology of film surfaces, it was found that the layer material was an amorphous matrix with inclusions of nanosized crystals. Calculation of the structure of the crystalline phase from synchrotron X-ray diffraction patterns demonstrated that the entire set of the diffraction peaks detected is indexed by a tetragonal structure with the lattice parameters a = 9.6 Å and c = 6.4 Å. This is consistent with the fact that the carbon 1s and nitrogen 1s core level X-ray photoelectron spectra exhibited only sp ³ bonding, which was expected for superhard carbon nitride phases.     

Activated carbon oxygen content influence on water and surfactant adsorption

This research investigates the adsorption properties of three activated carbons (AC) derived from coconut, coal, and wood origin. Each carbon demonstrates different levels of resistance to 2 M NaOH treatment. The coconut AC offers the greatest and wood AC the least resistance. The influence of base treatment is mapped in terms of its effects on specific surface area, micropore volume, water adsorption, and dodecanoic acid adsorption from both water and 2 M NaOH solution. A linear relationship exists between the number of water molecules adsorbed at the B-point of the water adsorption isotherm and the oxygen content determined from elemental analysis. Surfactant adsorption isotherms from water and 2 M NaOH indicate that the AC oxygen content effects a greater dependence on affinity for surfactant than specific surface area and micropore volume. We show a linear relationship between the plateau amount of surfactant adsorbed and the AC oxygen content in both water and NaOH phases. The higher the AC oxygen content, the lower the amount of surfactant adsorbed. In contrast, no obvious relationship could be drawn between the surfactant amount adsorbed and the surface area.     

On distribution over the cathode surface of the current due to positive ions in discharge with oscillating electrons

The mechanisms of processes determining distribution of positive ions on the cathode surface in a discharge with oscillating electrons are studied. At low pressures P≤5×10⁻⁵ torr over the entire range of anode length variation l _a=0.5–11 cm, the ion current distribution over the cathode radius J _i(r) features a single maximum in the center and drops steeply with distance from the axis. At pressures P=1–4×10⁻⁴ torr, the distribution J _i(r) for short anodes (l _a<6 cm) is similar to the previous one but, for long anodes (l _a=6–10 cm), new maxima at higher J _i values have been detected. A physical explanation for the obtained results is proposed.     

Distribution of electron flows over the cathode surface in a discharge with oscillating electrons

The mechanisms governing the distribution of the longitudinal electron flows over the cathode surface in a discharge with oscillating electrons are studied experimentally. The influence of the discharge gap length on the magnitude and distribution of the electron flows is investigated. It is shown that intense longitudinal electron flows in a tube of diameter d _a =31 mm can form only with short anodes of length l _a =2.5–3.5 cm. The distributions of the electron current over the cathode surface at various discharge conditions are determined.     

Solution of a problem of mendeleev type and the estimation of the derivatives of polynomials in the laguerre weighted space L2

Translated from Matematicheskie Zametki, Vol. 50, No. 1, pp. 10–18, July, 1991.     

γ-irradiation effect on transparent conducting ZnO:Ga films

Transparent and conducting pure and Ga-doped ZnO films prepared by e-beam evaporation in vacuum were irradiated at room temperature by Co⁶⁰ radiation source with the γ-photon average energy of 1.25 MeV and with different doses up to ∼600 kGy. The energy band gap E _g, electrical resistivity, carrier density as well as the structure parameters of pure and doped ZnO films versus the impurity content and γ-doses were determined in order to estimate the radiation-induced degradation effect on ZnO-based films used as transparent electrodes for electro-optical device applications.     

Application of High-Frequency Electron Paramagnetic Resonance/Electron Spin Echo for the Identification of the Impurity Composition and Electronic Structure of Ceramics Based Garnets

Physics of the Solid State - Electron paramagnetic resonance (EPR) spectra of Ce3+, Yb3+, Cr3+, and Gd3+ impurity ions in yttrium aluminum garnet Y3Al5O12 (YAG) ceramics were detected and...     

Synthesis of 4-Vinylmorpholine Based on Acetylene

It has been shown that from the possible methods for the synthesis of 4-vinylmorpholine, the vinylation of morpholine with acetylene remains acceptable. A technologically accessible method for vinylation of morpholine with acetylene at atmospheric pressure was developed.

     

Fast-hadron formation mechanism in leptoproduction in nuclei

The mechanism of fast-hadron leptoproduction in nuclei in deep inelastic region is considered. Different possible mechansims of fast-hadron formation in the virtual-photon fragmentation region and the process of transition of the quark (quark-gluon system) through nuclear matter is analysed. The range of consistency of the SLAC and EMC CERN data on meson leptoproduction in different nuclei is obtained to be 0.2 GeV²m _c ² 0.5 GeV². It is shown that the kinematic region 0.05x _B 0.3 and (3–5)Q ²/m _c ² 100 is the most favourable for an investigation of the growth law (evolution) of the transverse dimensions of quark (quark-gluon system) produced by the virtual photon.