Thermodynamic characteristics of thermal dissociation of inclusion compounds based on graphite fluorides

Thermal dissociation processes for acetonitrile inclusion compounds based on the polymer fluorographite host matrix C₂F _x Br_0.01·yCH₃CN, where x = 0.49?C0.92, y = 0.174?C0.285, are investigated. Thermodynamic parameters (??H°_av, ??S°_av, ??G°₂₉₈) for deintercalation of the compounds of the first filling step into the compounds of the second step and gaseous guest within temperature range 294?C352 K were determined. The effect of the host matrix fluorination degree on the thermodynamic characteristics of the studied processes is demonstrated.     

Transition-metal bimaleates and their solid solutions: Synthesis,structural, and thermoanalytical study

Transition-metal hydrogen maleates of composition M(C₄H₃O₄)₂ · 4H₂O, where M = Mn, Fe, Co, and Ni, and their solid solutions were synthesized and characterized by X-ray crystallography, IR spectroscopy, mass spectrometry, and thermal analysis. X-ray crystallography and IR spectroscopy showed that both intramolecular and intermolecular H-bonds exist in these compounds. The generation of continuous substitutional solid solutions with cation substitution in these compounds was studied. The thermolysis mechanism was studied for both transition-metal hydrogen maleates and their solid solutions. The composite produced by thermolysis is stable up to 1200°C in flowing helium.     

A monopole mass filter with a hyperbolic V-shaped electrode

In this article we compare the classical monopole mass filter of von Zahn and the monopole mass filter with a hyperbolic V-shaped electrode. The experimental results and those of computer simulation for both mass spectrometers are presented. We show that the replacement of a conventional 90 degrees V-shaped electrode by an electrode with a hyperbolic profile substantially improves the peak shape of any given mass, and increases the mass resolution by a factor of 3-4 and the abundance sensitivity by a factor of 100. The potential of high analytical performance combined with electroforming techniques for electrode manufacture indicate future practical uses of such instruments. Copyright 1999 John Wiley & Sons, Ltd.     

Measurement of two-mode squeezing with photon number resolving multipixel detectors

The measurement of the two-mode squeezed vacuum generated in an optical parametric amplifier (OPA) was performed with photon number resolving multipixel photon counters (MPPCs). Implementation of the MPPCs allows for the observation of noise reduction in a broad dynamic range of the OPA gain, which is inaccessible with standard single photon avalanche photodetectors.     

Polarization tomography of bright states of light

Polarization quantum tomography is performed on 4-mode squeezed vacuum states. Three-dimensional polarization quasiprobability functions are obtained and compared to that of an equal intensity coherent state. These distributions clearly demonstrate the difference in the polarization properties of the considered states. The reconstruction quality of the coherent state distribution is also analyzed by comparing the theoretically and experimentally obtained shapes for this state.     

The relationship between properties of fluorinated graphite intercalates and matrix composition

Inclusion compounds (intercalates) of fluorinated graphite matrix with methylene dichloride (C₂F _x Br _z ·yCH₂Cl₂, x = 0.49, 0.69, 0.87, 0.92, z ≈ 0.01) were synthesized by guest substitution from acetonitrile to methylene dichloride. The kinetics of the thermal decomposition (the first stage of filling → the second stage of filling) was studied under isothermal conditions at 291–303 K. The relationship between the structure of host matrices with thermal properties and kinetic parameters of inclusion compounds is discussed.