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91.
Alexander S. Lyakhov Pavel N. Gaponik Sergei V. Voitekhovich Ludmila S. Ivashkevich Alexander A. Kulak 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(10):1204-1206
There are two symmetry-independent molecules in the unit cell of the title compound, C7H5N5O3. The tetrazole and phenyl rings are essentially planar and are not coplanar in either molecule [dihedral angles 30.2 (1) and 7.0 (1)°]. In the structure, four molecules are connected by O—H⃛N bridges, forming four-membered molecular aggregates which are linked together by a complex three-dimensional hydrogen-bond network. 相似文献
92.
Alexander D. Vasiliev Alexander M. Astachov Yuri V. Kekin Ludmila A. Kruglyakova Rudolf S. Stepanov 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(10):1192-1193
The molecule of title compound, C2H7N3O2, has a zwitterionic structure. All non-H atoms, apart from the terminal N atom of the NH3 group, lie in the same plane, with a maximum deviation of 0.056 (1) Å for the amine N atom of the nitramine group, whereas the deviation of the terminal N atom of the NH3 group from the same plane is 1.222 (2) Å. Intermolecular hydrogen bonds within the crystal form a three-dimensional network. 相似文献
93.
Matienko Ludmila Zhigacheva Irina Mil Elena Albantova Anastasia Goloshchapov Alexander 《Molecules (Basel, Switzerland)》2022,27(11)
The role of ligands in the regulation of the catalytic activity of Ni-complexes (Ni(acac)2) in green process-selective ethylbenzene oxidation with O2 into α-phenyl ethyl hydroperoxide is considered in this article. The dual function of phenol (PhOH) included in the coordination sphere of the nickel complex as an antioxidant or catalyst depends on the ligand environment of the metal. The role of intermolecular H-bonds and supramolecular structures (AFM method) in the mechanisms of selective catalysis by nickel complexes in chemical and biological oxidation reactions is analyzed. 相似文献
94.
Dr. Ludmila Krejčová Dr. Terza Leonhardt Dr. Filip Novotný Dr. Vilém Bartůněk Dr. Vlastimil Mazánek Prof. David Sedmidubský Prof. Zdeněk Sofer Prof. Martin Pumera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(15):3828-3834
Nature and its highly sophisticated biomaterials are an endless source of inspiration for engineers and scientists across a wide range of disciplines. During the last decade, concepts of bioinspired synthesis of hierarchically structured nano- and micromaterials have been attracting increasing attention. In this article, we have utilized the natural ability of fungi to absorb metal ions for a bioinspired synthesis of carbonaceous material doped by selected transition metals. As an all-around metal accumulator, Hebeloma mesophaeum was selected, and it was cultivated in the presence of three transition-metal ions: NiII, FeII, and MnII. The metal-doped carbonized biomaterial possessed enhanced catalytic activity toward hydrazine oxidation, oxygen reduction, and cumene hydroperoxide reduction. Thus, we have shown possible transformation of a waste product (fungi grown on a contaminated soil) into a value-added carbonaceous material with tailored catalytic properties. This bioinspired synthesis can outline an attractive route for the fabrication of catalysts for important industrial applications on a large scale. 相似文献
95.
96.
Anatoly N. Trukhin Janis L. JansonsTatyana I. Dyuzheva Ludmila M. LityaginaNikolai A. Bendeliani 《Solid State Communications》2003,127(6):415-418
Luminescence of very small samples of single crystals of coesite and stishovite has been studied. The spectra were detected under ionizing radiation (X-ray and electron beam) and the decay kinetics of cathodoluminescence in the range of time from 10 ns to 3 ms was measured. The coesite luminescence possesses a broad band at 3 eV with exponential decay about 680 μs at 80 K. The nature of this luminescence was explained as a self-trapped exciton creation in tetrahedron framework. The stishovite luminescence possesses two bands—blue (2.8 eV) and UV (4.7 eV). The UV band intensity grows more than 20 times with irradiation dose from initial level. This shows that the corresponding luminescence centers could be induced by the radiation. The decay of the UV band possesses a fast and a slow component. The determination of the fast decay parameters is beyond the capabilities of our apparatus (less than 10 ns), whereas the slow decay of the UV is non-exponential and takes place in the range of hundreds of microsecond. The blue band decay kinetics can be well approximated by power law ∼t−2, which may correspond to recombination of defects created by radiation. The stishovite single crystal luminescence is very similar to that of germanium dioxide single crystal of rutile structure. The nature of the stishovite luminescence is explained as recombination of defects created by irradiation in octahedron-structured lattice. 相似文献
97.
Vladimir G. Neudatchin Igor T. Obukhovsky Ludmila L. Sviridova Nikolai P. Yudin 《Central European Journal of Physics》2004,2(3):511-522
The pion momentum distributions (MDs) in four channels of virtual decay p→B+π, B = N, Δ, N
1/2-(1535), N
1/2+(1440) are calculated in two models, the microscopic model of 3
P
0 scalar q−q fluctuation with the pion as a composite q−q-system and the chiral semi-microscopic model of πq interaction with the pion as a structureless Goldstone boson. The results of the above models are similar for the baryon
states B = N, Δ, N
1/2-(1535) but are rather different for the Roper resonance N
1/2+(1440) which corresponds to excitation of two oscillator quanta in the nucleon. The experimental investigation of pion MDs
by means of the reaction of quasi-elastic knockout of pion by an electron of a few GeV energy p(e, e′ π)B may be very suitable for Jefferson Laboratory, Virginia (JLab). 相似文献
98.
A two-dimensional non-isothermal stationary mathematical model of the catalytic membrane reactor for the process of methanol dehydrogenation is described. Copper supported on the carbonaceous support was considered as a catalyst. The reaction of methanol dehydrogenation was thermodynamically conjugated with a reaction of hydrogen oxidation taking place in a shell side of the membrane reactor. The effects of various parameters on the methanol conversion and the methyl formate yield have been calculated with the developed model and discussed. Two different types of heating the gas flow were considered and compared. In the case of conjugated dehydrogenation process, the methyl formate yield reaches 77%, when the reactor outer wall was heated up to 150 °C. When the inlet gas flows in the tube and shell sides were heated up to 100 and 83 °C, correspondingly, the yield was 72%. 相似文献
99.
100.
The aim of this study was to obtain quantitative characteristics of the ultraviolet absorption spectra as the molecular absorptivity at the wavelength of maximum absorbance. Organic as well as inorganic compounds were explored. A gas chromatography—ultraviolet absorption instrument has been used in the quantitative study of molecular ultraviolet absorption spectra in the vapour phase. The wavelength range studied was between 168 and 330?nm. The absorbance of 170 compounds was determined relative to perchloroethylene and their molecular absorptivities were calculated. For various groups of compounds, these relative absorptivities varied within two to three orders of magnitude. Standard curves were linear within four orders of magnitude from limit of quantification up to an absorption value of 1.5 absorbance units. The noise level was 3?×?10?5 absorbance units peak to peak at a bandwidth of 1.7?nm and a wavelength range from 180 to 330?nm was preferred. The detection limit for mesitylene was calculated to be 2 pg/s and for naphthalene 1 pg/s with 4?s store cycle time. 相似文献