排序方式: 共有46条查询结果,搜索用时 15 毫秒
41.
E. A. Legurova S. Sladkevich O. Lev M. A. Fedotov D. F. Khabibulin T. A. Tripol’skaya P. V. Prikhodchenko 《Russian Journal of Inorganic Chemistry》2009,54(6):824-828
Stable amorphous potassium peroxostannate nanoparticles with controlled sizes (10–100 nm), morphology, and hydrogen peroxide percentage (19–30 wt %) were synthesized for the first time. The compounds were characterized by vibrational spectroscopy, 119Sn MAS NMR spectroscopy, powder X-ray diffraction, and thermogravimetry. These characteristics were compared to those for K2Sn(OH)6 and K2Sn(OOH)6. Potassium peroxostannate particles are mainly built of peroxo-bridged polymer chains. The particles are stable when stored in a dry state or suspended in nonaqueous solvents; in contact with water, they release hydrogen peroxide. 相似文献
42.
G. D. Kolomnikova D. Yu. Prikhodchenko S. A. Kuznetsova P. V. Petrovskii L. F. Kasukhin Yu. G. Gololobov 《Russian Chemical Bulletin》1992,41(2):337-341
The vinyl esters of phosphorus acids containing an -chloromethylalkenyl substituent react readily with thiourea to form substituted phosphorylated S-isothiuronium chlorides, capable of being dialkylated to the corresponding internal salts (betaines). An allylic rearrangement was discovered for the first time in the series of substituted S-isopropenylisothiuronium salts. The anticholinesterase and toxicological characteristics of some of the obtained comopunds were measured and compared.For previous communication, see [1].A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 425–430, February, 1992. 相似文献
43.
Vandana Tripathi Lagy T Baby PV Madhusudhana Rao SK Hui R Singh JJ Das P Sugathan N Madhavan AK Sinha 《Pramana》1999,53(3):535-539
The ground state and excited state transfer yields for the 2-neutron pickup channel in the 28Si+68Zn system have been measured explicitly. The recoil mass separator at the nuclear Science Centre, New Delhi was used for the
measurement. A NaI(T1) detector was used for detecting the deexcitation γ’s from the transfer products. The kinematic coincidence technique was employed for the transfer measurement. Simplified coupled
channels calculations show that out of all transfer channels the major contribution to the sub-barrier enhancement comes from
the ground state 2 neutron pickup channel with a ground state Q-value of+1.83 MeV. 相似文献
44.
The present study explores the free convective oblique Casson fluid over a stretching surface with non-linear thermal radiation effects. The governing physical problem is modelled and transformed into a set of coupled non-linear ordinary differential equations by suitable similarity transformation, which are solved numerically with the help of shooting method keeping the convergence control of 10-5 in computations. Influence of pertinent physical parameters on normal, tangential velocity profiles and temperature are expressed through graphs. Physical quantities of interest such as skin friction coefficients and local heat flux are investigated numerically. 相似文献
45.
Vener MV Medvedev AG Churakov AV Prikhodchenko PV Tripol'skaya TA Lev O 《The journal of physical chemistry. A》2011,115(46):13657-13663
The structure, IR spectrum, and H-bond network in the serine-H(2)O and serine-H(2)O(2) crystals were studied using DFT computations with periodic boundary conditions. Two different basis sets were used: the all-electron Gaussian-type orbital basis set and the plane wave basis set. Computed frequencies of the IR-active vibrations of the titled crystals are quite different in the range of 10-100 cm(-1). Harmonic approximation fails to reproduce IR active bands in the 2500-2800 frequency region of serine-H(2)O and serine-H(2)O(2). The bands around 2500 and 2700 cm(-1) do exist in the anharmonic IR spectra and are caused by the first overtone of the OH bending vibrations of H(2)O and a combination vibration of the symmetric and asymmetric bendings of H(2)O(2). The quantum-topological analysis of the crystalline electron density enables us to describe quantitatively the H-bond network. It is much more complex in the title crystals than in a serine crystal. Appearance of water leads to an increase of the energy of the amino acid-amino acid interactions, up to ~50 kJ/mol. The energy of the amino acid-water H-bonds is ~30 kJ/mol. The H(2)O/H(2)O(2) substitution does not change the H-bond network; however, the energy of the amino acid-H(2)O(2) contacts increases up to 60 kJ/mol. This is caused by the fact that H(2)O(2) is a much better proton donor than H(2)O in the title crystals. 相似文献
46.
Alexander G. Medvedev Alexey A. Mikhaylov Andrei V. Churakov Petr V. Prikhodchenko Ovadia Lev 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(3):i20-i24
Diammonium carbonate hydrogen peroxide monosolvate, 2NH4+·CO32−·H2O2, (I), and dicaesium carbonate hydrogen peroxide trisolvate, 2Cs+·CO32−·3H2O2, (II), were crystallized from 98% hydrogen peroxide. In (I), the carbonate anions and peroxide solvent molecules are arranged on twofold axes. The peroxide molecules act as donors in only two hydrogen bonds with carbonate groups, forming chains along the a and c axes. In the structure of (II), there are three independent Cs+ ions, two of them residing on twofold axes, as are two of the four peroxide molecules, one of which is disordered. Both structures comprise complicated three‐dimensional hydrogen‐bonded networks. 相似文献