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41.
Kamarchik E Rodrigo C Bowman JM Reisler H Krylov AI 《The Journal of chemical physics》2012,136(8):084304
The dissociation of the hydroxymethyl radical, CH(2)OH, and its isotopolog, CD(2)OH, following the excitation of high OH stretch overtones is studied by quasi-classical molecular dynamics calculations using a global potential energy surface (PES) fitted to ab initio calculations. The PES includes CH(2)OH and CH(3)O minima, dissociation products, and all relevant barriers. Its analysis shows that the transition states for OH bond fission and isomerization are both very close in energy to the excited vibrational levels reached in recent experiments and involve significant geometry changes relative to the CH(2)OH equilibrium structure. The energies of key stationary points are refined using high-level electronic structure calculations. Vibrational energies and wavefunctions are computed by coupled anharmonic vibrational calculations. They show that high OH-stretch overtones are mixed with other modes. Consequently, trajectory calculations carried out at energies about ~3000 cm(-1) above the barriers reveal that despite initial excitation of the OH stretch, the direct OH bond fission is relatively slow (10 ps) and a considerable fraction of the radicals undergoes isomerization to the methoxy radical. The computed dissociation energies are: D(0)(CH(2)OH → CH(2)O + H) = 10,188 cm(-1), D(0)(CD(2)OH → CD(2)O + H) = 10,167 cm(-1), D(0)(CD(2)OH → CHDO + D) = 10,787 cm(-1). All are in excellent agreement with the experimental results. For CH(2)OH, the barriers for the direct OH bond fission and isomerization are: 14,205 and 13,839 cm(-1), respectively. 相似文献
42.
V. A. Krylov 《Journal of Analytical Chemistry》2002,57(8):660-671
The current status of the analysis of high-purity volatile substances is considered. Two types of impurities in high-purity volatile substances were distinguished: molecularly dissolved substances and suspended particles. The main factors that restrict the limiting capabilities of analytical techniques were revealed. The attained detection limits were 10–8–10–10% for metal impurities, 10–4–10–8% for organic substances, 10–5–10–9% for water, and 10–5–10–7 for permanent gases. Suspended particles of 0.04–0.003 m in size were determined by light scattering. 相似文献
43.
Krylov V. B. Ushakova N. A. Ustyuzhanina N. E. Preobrazhenskaya M. E. Yashunsky D. V. Menshov V. M. Tsvetkov D. E. Sharma G. V. M. Radha Krishna P. Nifantiev N. E. 《Russian Chemical Bulletin》2010,59(1):232-235
Persulfated derivatives of natural polyhydroxy compounds, such as lignans secoisolariciresinol, and isolariciresinol, flavonoid
dihydroquercetin, and myo-inositol, have been synthesized. The ability of these compounds to inhibit the intrinsic pathway of blood coagulation (APTT-test)
and to reduce the activity of coagulation factor Xa in the presence of antithrombin(III) has been studied. 相似文献
44.
Implementation of Dyson orbitals for coupled-cluster and equation-of-motion coupled-cluster wave functions with single and double substitutions is described and demonstrated by examples. Both ionizations from the ground and electronically excited states are considered. Dyson orbitals are necessary for calculating electronic factors of angular distributions of photoelectrons, Compton profiles, electron momentum spectra, etc, and can be interpreted as states of the leaving electron. Formally, Dyson orbitals represent the overlap between an initial N-electron wave function and the N-1 electron wave function of the corresponding ionized system. For the ground state ionization, Dyson orbitals are often similar to the corresponding Hartree-Fock molecular orbitals (MOs); however, for ionization from electronically excited states Dyson orbitals include contributions from several MOs and their shapes are more complex. The theory is applied to calculating the Dyson orbitals for ionization of formaldehyde from the ground and electronically excited states. Partial-wave analysis is employed to compute the probabilities to find the ejected electron in different angular momentum states using the freestanding and Coulomb wave representations of the ionized electron. Rydberg states are shown to yield higher angular momentum electrons, as compared to valence states of the same symmetry. Likewise, faster photoelectrons are most likely to have higher angular momentum. 相似文献
45.
Thermal oxidative treatment enhances the activity of a schungite rock in the sorption of petrochemicals from aqueous solutions.
The effect of the thermal oxidative activation on the content and distribution of carbon in the rock and the dependence of
the sorption activity on the texture of sorbents were studied.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2233–2238, October, 2005. 相似文献
46.
S. E. Boganov M. P. Egorov V. I. Faustov I. V. Krylov O. M. Nefedov R. Becerra R. Walsh 《Russian Chemical Bulletin》2005,54(3):483-511
The results of time resolved gas phase studies of labile germylenes (GeH2 and GeMe2) and dimethylstannylene (SnMe2) reactions reported to date are considered together with data of quantum-chemical investigations of the potential energy surfaces of these systems. Reaction mechanisms are discussed. A comparison of reactivity in the series of carbene analogs, ER2 (E = Si, Ge, Sn, R = H, Me), is made.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 477–505, March, 2005. 相似文献
47.
Yu. A. Simonov M. S. Fonar' E. V. Ganin A. A. Dvorkin G. G. Musienko E. N. Krylov T. I. Malinovskii 《Journal of Structural Chemistry》1992,33(2):278-283
Applied Physics Institute, Moldovian Academy of Sciences. Technical Physics Institute, Ukrainian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 2, pp. 138–144, March–April, 1992. 相似文献
48.
49.
Dr. Vasily G. Panferov Nikita A. Ivanov Dr. Tony Mazzulli Dr. Davor Brinc Dr. Vathany Kulasingam Prof. Sergey N. Krylov 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202215548
Lateral flow immunoassay (LFIA) is a rapid, simple, and inexpensive point-of-need method. A major limitation of LFIA is a high limit of detection (LOD), which impacts its diagnostic sensitivity. To overcome this limitation, we introduce a signal-enhancement procedure that is performed after completing LFIA and involves controllably moving biotin- and streptavidin-functionalized gold nanoparticles by electrophoresis. The nanoparticles link to immunocomplexes forming multilayer aggregates on the test strip, thus, enhancing the signal. Here, we demonstrate lowering the LOD of hepatitis B surface antigen from approximately 8 to 0.12 ng mL−1, making it clinically acceptable. Testing 118 clinical samples for hepatitis B showed that signal enhancement increased the diagnostic sensitivity of LFIA from 73 % to 98 % while not affecting its 95 % specificity. Electrophoresis-driven enhancement of LFIA is universal (antigen-independent), takes two minutes, and can be performed by an untrained person. 相似文献
50.
This work is devoted to the investigation of projective modules over generalized matrix rings. 相似文献