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71.
Kazankov G. M. Sergeeva V. S. Borisenko A. A. Zatsman A. I. Ryabov A. D. 《Russian Chemical Bulletin》2001,50(10):1844-1848
Cyclometallated aryl ketoximes are introduced as catalysts for hydrolysis of organophosphorus neurotoxins. Platinum-containing catalysts exhibit the highest activity and selectivity with respect to O-alkyl phosphorothioates (parathion, methyl parathion, coumaphos) and efficiently promote the hydrolysis of S-alkyl phosphorothioates and -dithioates (demeton-S, malathion) at the P—S bonds. 相似文献
72.
N. V. Averina G. S. Borisova A. A. Borisenko N. S. Zefirov 《Russian Journal of Organic Chemistry》2001,37(7):957-963
UV irradiation of trans-trans-3,7-bis(arylmethylene)bicyclo[3.3.1]nonane-2,6-diones leads to their complete or partial transformation into the corresponding cis-cis isomers. Irradiation of trans-trans-3,7-bis(arylmethylene)bicyclo[3.3.1]nonane-2,6-diol in ether in the presence of CuCl results in intramolecular cyclization involving the exocyclic double bonds and one benzene ring to give exo-7endo-10-dihydroxy-2-phenyl-3,4-benzotetracyclo[4.3.3.18,11.01,6]tridecane. 相似文献
73.
In this study,the three dimensional nanoscale organization in the photoactive layers of poly(3-hexylthiophene) (P3HT) and a methanofullerene derivative (PCBM) is revealed by transmission electron tomography.After annealing treatment,either at elevated temperature or during slow solvent evaporation,nanoscale interpenetrating networks are formed with high crystalline order and favorable concentration gradients of both components through the thickness of the photoactive layer.Such a tailored morphology acco... 相似文献
74.
The microstructure of strained β-PbF2 crystals is investigated by optical and scanning electron microscopy. It is established that the α-PbF2 previously observed by x-ray diffraction methods during the straining of cubic PbF2 nucleates predominantly on structural defects like slip lines and bands. The kinetics of the growth of α-PbF2 particles during the straining of β-PbF2 crystals and during a postdeformation anneal is investigated. The results of the experiments point to the involvement of
diffusion in the growth of α-PbF2.
Fiz. Tverd. Tela (St. Petersburg) 39, 640–646 (April 1997) 相似文献
75.
76.
Conclusions The correlational relation between the chemical shift of the NMR of the N14 nitrogen and frequencies of antisymmetric valence vibrations of the nitro group in the IR spectra of nitro compounds was found.Translated from Izvestiya Academii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 675–676, March, 1968. 相似文献
77.
Saddle submanifolds are considered. A characterization of such submanifolds of Euclidean space is given in terms of sectional curvature. Extending results of T. Frankel, K. Kenmotsu and C. Xia, we determine under what conditions two complete saddle submanifolds of a complete connected Riemannian manifold M, with nonnegative k-Ricci curvature, must intersect. Moreover, if M has positive k -Ricci curvature and the dimension of a compact saddle submanifold satisfies a certain inequality then we show that the homomorphism of the fundamental groups 1(M) and 1(M) is surjective. 相似文献
78.
Hinchley SL Robertson HE Borisenko KB Turner AR Johnston BF Rankin DW Ahmadian M Jones JN Cowley AH 《Dalton transactions (Cambridge, England : 2003)》2004,(16):2469-2476
The molecular structure of tetra-tert-butyldiphosphine has been determined in the gas phase by electron diffraction using the new DYNAMITE method and in the crystalline phase by X-ray diffraction. Ab initio methods were employed to gain a greater understanding of the structural preferences of this molecule in the gas phase, and to determine the intrinsic P-P bond energy, using recently described methods. Although the P-P bond is relatively long [GED 226.4(8) pm; X-ray 223.4(1) pm] and the dissociation energy is computed to be correspondingly small (150.6 kJ mol(-1)), the intrinsic energy of this bond (258.2 kJ mol(-1)) is normal for a diphosphine. The gaseous data were refined using the new Edinburgh structure refinement program ed@ed, which is described in detail. The molecular structure of gaseous P(2)Bu(t)(4) is compared to that of the isoelectronic 1,1,2,2-tetra-tert-butyldisilane. The molecules adopt a conformation with C(2) symmetry. The P-P-C angles returned from the gas electron diffraction refinement are 118.8(6) and 98.9(6) degrees, a difference of 20 degrees, whilst the C-P-C angle is 110.3(8) degrees. The corresponding parameters in the crystal are 120.9(1), 99.5(1) and 109.5(1) degrees. There are also large deformations within the tert-butyl groups, making the DYNAMITE analysis for this molecule extremely important. 相似文献
79.
A. Nylandsted Larsen V. E. Borisenko 《Applied Physics A: Materials Science & Processing》1984,33(1):51-58
The behaviour of ion-implanted arsenic in 100-oriented silicon single crystals exposed to continuous incoherent light from a xenon arc lamp has been analyzed with sheet resistivity measurements, Rutherford backscattering spectrometry, and ion channeling including angular scans. Redistribution, substitutionality, and electrical activity of arsenic were followed as functions of exposure time (6–20s) and induced temperature (1000°–1100°C). Redistribution was observed for implanted concentrations exceeding 4×1020 at.%/cm3. High substitutional fractions, between 95% and 99%, and low sheet resistivities were found for all annealed samples. Formation mechanism of arsenic substitutional solid solutions during transient heating of implanted layers is discussed. 相似文献
80.
The adequacy of the density functional derived scaled quantum mechanical force field method of Rauhut and Pulay has been tested for a weakly bound dimer, N2O4. The Becke3–Lee–Yang–Parr/6-31G* harmonic force field has been scaled with the transferable scale factors of Rauhut and Pulay (developed originally for `common' organic compounds without any reference to the N–O bond) resulting in 20.7 and 38 cm−1 for the mean and the maximal individual deviations, respectively, as compared with experimental spectra. Consequently, the force field method of Rauhut and Pulay may give reliable results for non-common compounds as well. 相似文献