Conductivity of island metal films covered with organic molecules

Experimental data were obtained on the effect of adsorbed organic molecules (naphthalene, stearone, benzene, xylene, aluminum oxyquinoline and mixtures of some aliphatic compounds) on the conductivity of gold island films. Nanoisland structures were realized which exhibit non-linear conduction current–voltage characteristics and a sharp switching effect in the presence of adsorbed organics. The conditions for the occurrence of the voltage-controlled negative resistance in such nanocomposite systems are discussed. Some data are also given on electroluminescence of the nanocomposites. Two theoretical models are suggested to describe the conduction current–voltage characteristics of organic molecular structures under various conditions.     

Synthesis and some properties of 2,3-dihydrofuro[2,3-b]quinol-4-one

The reaction of O-ethylbutyrolactonium tetrafluoroborate with ethyl anthranilate gave the corresponding imido ester, which undergoes cyclization to a furo[2,3-b]-quinol-4-one derivative when it is heated in a solution of sodium butoxide. When the latter product is heated in diphenyl oxide, it is converted to a furo[3,2-c]-quinol-2-one derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 65–67, January, 1982.     

The effect of alloying on the structure and peculiarities of tribological behavior of vacuum-deposited diamond-like coatings

In this work, we report the results of a study of the atomic and crystalline structures, phase and chemical compositions and tribological properties of DLC coatings deposited by plasma-assisted (PA) CVD (a-C:H:Si and a-C:H:Si:Mo) and magnetron reactive sputtering (a-C:H:Cr). The a-C:H:Si:Mo coatings revealed the formation of ultra-dispersed inclusions of either molybdenum carbides or silicides, whereas no such inclusions were found in the a-C:H:Si compound. The a-C:H:Cr coatings that were deposited in an acetylene–nitrogen gas mixture exhibited a nanocomposite structure composed of chromium, its carbide and nitride phases. The tribological tests showed that the DLC coatings with silicon and silicon–molybdenum have a high friction coefficient and a low working performance, while the chromium-containing coatings have high levels of their mechanical and tribological characteristics, making them promising materials for operation under high contact pressures.     

Molecule length-induced reentrant self-organization of alkanes in monolayers adsorbed on Au(111)

We report the observation by scanning tunneling microscopy of the reentrant self-organization of n-alkanes (C(n)H(2n+2)) in monolayers adsorbed on Au(111) induced by a variation of the chain length. In the investigated range of lengths ( 10相似文献   

On the natural frequencies of some three-dimensional cylindrical bodies

We give examples of three-dimensional bodies such that a two-term asymptotic formula holds for the number of eigenvalues of the boundary value problem Δu + λu = 0, ?u/?n + σu = 0.     

Correction to: The Structure and Properties of Microcrystalline and Submicrocrystalline Titanium Alloy VT1-0 in the Area of the Electron Beam Welding Seam

Russian Physics Journal - There was a misprint in the first author’s affiliation (V. A. Klimenov). It should read National Research Tomsk Polytechnic University instead of National Research...     

Determination of zirconium using morin immobilized on silica gel

The sorption of 5,7,2′,4′-tetrahydroxyflavonol from butanol and acetone-hexane (1:4) solutions on highly dispersed silica was studied. A solid-phase reagent is proposed for the sorption-spectrophotometric determination of down to 30 μg/L of zirconium(IV).     

Structural evidence for Pπ-Pπ conjugation in aminosubstituted phosphaalkynes

The molecular structure of 2,2,6,6-tetramethylpiperidinophosphaalkyne was determined by the X-ray structural method. The main geometrical parameters are as follows: PC 1.559(2), N C(sp) 1.316(2) Å, PC N 178.9(1)°, with an almost planar trigonal bond configuration for the N atom and the chair conformation of the piperidine ring. Structural evidence for the nitrogen lone pair conjugation with the π-system of the triple bond was found to be different in phosphaalkynes PC-NR₂ and nitriles NC NR₂. Quantum-chemical ab initio calculations (HF/631G*) showed that this is caused by a different character of polarization of the PC and NC triple bonds.     

Cathodoluminescence and selective emission of Er<Superscript>3+</Superscript> in oxides

The dependence of the Er³⁺ cathodoluminescence and selective emission on the power of the YAG:Er³⁺ and Er₂O₃ excitation by an electron beam is spectroscopically studied for applications in high-intensity radiation sources of the visible and near-IR spectral ranges.