Reaction of mercaptopyrimidine derivatives with perfluoro olefins

The reaction of methyl and hydroxy derivatives of 2- and 4-mercaptopyrimidines with perfluoropropylene and perfluoro-1-hexene was investigated. The corresponding perfluoroalkenylthio-substituted pyrimidines are described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 402–406, March, 1984.     

Structure of the residual carbon made by fluorocarbon pyrolysis

All-Electron Electrocarbon Research and Development Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 3, pp. 48–52, May–June, 1990.     

The structure of pyrolytic carbon of different types

Summary The structure of pyrolytic carbon of various types has been investigated by the following methods: microstructural, electron-microscopic, X-ray structural, and microdiffractional analysis. Inter-particle regions have been discovered in pyrolytic carbon, which determine its anisotropic structure. It has been shown that thermal treatment of pyrolytic carbon at temperatures above 3000° results in the formation of blocks having a mosaic sub-structure, which cause a reduction in the azimuthal disorientation of carbon produced at a temperature higher than 2000° in a vacuum, corresponding to the structure of amorphized natural carbon.Translated from Zhurnal Strukturnoi Khimii, Vol. 6, No. 1, pp. 66–69, January–February, 1965 Original     

Classical electron ionization mass spectra in gas chromatography/mass spectrometry with supersonic molecular beams

A major benefit of gas chromatography/mass spectrometry (GC/MS) with a supersonic molecular beam (SMB) interface and its fly-through ion source is the ability to obtain electron ionization of vibrationally cold molecules (cold EI), which show enhanced molecular ions. However, GC/MS with an SMB also has the flexibility to perform 'classical EI' mode of operation which provides mass spectra to mimic those in commercial 70 eV electron ionization MS libraries. Classical EI in SMB is obtained through simple reduction of the helium make-up gas flow rate, which reduces the SMB cooling efficiency; hence the vibrational temperatures of the molecules are similar to those in traditional EI ion sources. In classical EI-SMB mode, the relative abundance of the molecular ion can be tuned and, as a result, excellent identification probabilities and very good matching factors to the NIST MS library are obtained. Classical EI-SMB with the fly-through dual cage ion source has analyte sensitivity similar to that of the standard EI ion source of a basic GC/MS system. The fly-through EI ion source in combination with the SMB interface can serve for cold EI, classical EI-SMB, and cluster chemical ionization (CCI) modes of operation, all easily exchangeable through a simple and quick change (not involving hardware). Furthermore, the fly-through ion source eliminates sample scattering from the walls of the ion source, and thus it offers full sample inertness, tailing-free operation, and no ion-molecule reaction interferences. It is also robust and enables increased column flow rate capability without affecting the sensitivity.     

Carbon application in chemical power sources

The studies concerned with the effect of carbon on specific characteristics of chemical power sources (CPS) are reviewed. The influence exerted by a three-dimensional ordering of the structure, dispersion degree, surface properties, and porous structure of carbon particles on the current-producing reactions occurring at the CPS electrodes is analyzed. Prospects for the application of intercalated carbon compounds as positive and negative electrodes of CPS are demonstrated.     

发光玻璃在X射线实时成像系统中的应用

介绍了以铽（Ｔｂ）激活的高密度发光玻璃和光导纤维发光玻璃的特性。它应用在Ｘ射线实时成像系统中,可大大改善空间分辨能力。用它做的转换屏比一般晶粒状荧光物质做的厚得多,特别适合用于高能Ｘ射线实时成像系统     

Pulsed flow modulation two-dimensional comprehensive gas chromatography-tandem mass spectrometry with supersonic molecular beams

Pulsed flow modulation (PFM) two-dimensional comprehensive gas chromatography (GC x GC) was combined with quadrupole-based mass spectrometry (MS) via a supersonic molecular beam (SMB) interface using a triple-quadrupole system as the base platform, which enabled tandem mass spectrometry (MS-MS). PFM is a simple GC x GC modulator that does not consume cryogenic gases while providing tunable second GC x GC column injection time for enabling the use of quadrupole-based mass spectrometry regardless its limited scanning speed. The 20-ml/min second column flow rate involved with PFM is handled, splitless, by the SMB interface without affecting the sensitivity. The combinations of PFM GC x GC-MS with SMB and PFM GC x GC-MS-MS with SMB were explored with the analysis of diazinon and permethrin in coriander. PFM GC x GC-MS with SMB is characterized by enhanced molecular ion and tailing-free fast ion source response time. It enables universal pesticide analysis with full scan and data analysis with reconstructed single ion monitoring on the enhanced molecular ion and another prominent high mass fragment ion. The elimination of the third fragment ion used in standard three ions method results in significantly reduced matrix interference. GC x GC-MS with SMB improves the GC separation, and thereby our ability for sample identification using libraries. GC-MS-MS with SMB provides better reduction (elimination) of matrix interference than GC x GC-MS. However, it is a target method, which is not always applicable. GC x GC-MS-MS does not seem to further reduce matrix interferences over GC-MS-MS and unlike GC x GC-MS, it is incompatible with library identification, but it is beneficial to have both GC x GC and MS-MS capabilities in the same system.     

Mass-spectrometric investigation of boron derivatives of fluorinated β-diketones

A series of complexes of fluorinated -diketones with boron difluoride were synthesized. Paths of their fragmentation and stability during an electron impact were established. For the complexes studied in the gaseous phase, a specific decomposition of perfluorinated and adamantyl groups with the formation of new -diketonate ions with a linear or cyclic structure is characteristic. The possibility of capture of hydrogen atoms by the -diketonate ions in the gaseous phase has been discovered.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 1, pp. 110–113, January–February, 1986.