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51.
A. P. Pokutsa A. B. Zaborovskii D. S. Maksim 《Russian Journal of Applied Chemistry》2007,80(11):1822-1825
Decomposition of hydrogen peroxide in organic hydrophilic solvents, catalyzed by cobalt(II) palmitate [Co(palm)2], was studied by the method of inhibitors. 相似文献
52.
Based on a high level ab initio calculation which is carried out with the multireference configuration interaction method under the aug-cc-pVXZ (AVXZ) basis sets, X=T, Q, 5, the accurate potential energy curves (PECs) of the ground state ${rm{X}}{}^{{rm{1}}}{rm{Sigma }}_{g}^{+}$ and the first excited state ${rm{A}}{}^{{rm{1}}}{rm{Sigma }}_{u}^{+}$ of Li2 are constructed. By fitting the ab initio potential energy points with the Murrell–Sorbie potential function, the analytic potential energy functions (APEFs) are obtained. The molecular bond length at the equilibrium (Re), the potential well depth (De), and the spectroscopic constants (Be, ωe, αe, and ωeχe) for the ${rm{X}}{}^{{rm{1}}}{rm{Sigma }}_{g}^{+}$ state and the ${rm{A}}{}^{{rm{1}}}{rm{Sigma }}_{u}^{+}$ state are deduced from the APEFs. The vibrational energy levels of the two electronic states are obtained by solving the time-independent Schrödinger equation with the Fourier grid Hamiltonian method. All the spectroscopic constants and the vibrational levels agree well with the experimental results. The Franck–Condon factors (FCFs) corresponding to the transitions from the vibrational level (v′=0) of the ground state to the vibrational levels (v″=0–74) of the first excited state have been calculated. The FCF for the vibronic transition of ${rm{A}}{}^{{rm{1}}}{rm{Sigma }}_{u}^{+}$(v″=0) ←${rm{X}}{}^{{rm{1}}}{rm{Sigma }}_{g}^{+}$(v′=0) is the strongest. These PECs and corresponding spectroscopic constants provide reliable theoretical references to both the spectroscopic and the molecular dynamic studies of the Li2 dimer. 相似文献
53.
Joseph Czekner Ling Fung Cheung G. Stephen Kocheril Maksim Kulichenko Alexander I. Boldyrev Lai‐Sheng Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8969-8973
In a high‐resolution photoelectron imaging and theoretical study of the IrB3? cluster, two isomers were observed experimentally with electron affinities (EAs) of 1.3147(8) and 1.937(4) eV. Quantum calculations revealed two nearly degenerate isomers competing for the global minimum, both with a B3 ring coordinated with the Ir atom. The isomer with the higher EA consists of a B3 ring with a bridge‐bonded Ir atom (Cs , 2A′), and the second isomer features a tetrahedral structure (C3v , 2A1). The neutral tetrahedral structure was predicted to be considerably more stable than all other isomers. Chemical bonding analysis showed that the neutral C3v isomer involves significant covalent Ir?B bonding and weak ionic bonding with charge transfer from B3 to Ir, and can be viewed as an Ir–(η3‐B3+) complex. This study provides the first example of a boron‐to‐metal charge‐transfer complex and evidence of a π‐aromatic B3+ ring coordinated to a transition metal. 相似文献
54.
Sergey N. Podoynitsyn Olga N. Sorokina Maksim A. Klimov Igor I. Levin Sergey B. Simakin 《SEPARATION SCIENCE PLUS》2019,2(2):59-68
Barrier contactless dielectrophoresis is proposed as a method for microbiological particle separation. Design of a separation device for barrier contactless dielectrophoresis is discussed. The principle of separation device is based on formation of barriers of gradient fields in the volume of separation chamber by electrodes with passivation dielectric coating of silicon carbide. A feature of the method is absence of contact between separated samples and conductive elements of electrode structure. The proposed method is highly efficient and easy to use in comparison with dielectrophoresis on isolated structures and conventional planar systems. Computer simulation of electric field distribution over dielectrophoretic barriers is carried out, and effect of the thickness of the passivation coating on dielectrophoretic properties of barriers is shown. Forces acting on a particle (a yeast cell with a diameter of 7 μm) in separation chamber are evaluated using computer simulation data. Ability of the cell to be captured by the method of contactless barrier dielectrophoresis is theoretically predicted and confirmed experimentally, using yeast cells. The yeast cells subjected to positive dielectrophoresis can be effectively captured (up to 90%) by the separation device at the applied voltage of 20 V and 100 kHz and at flow rate of 20 mL/h. 相似文献
55.
Maksim V. Dolgopolik 《Numerical Functional Analysis & Optimization》2018,39(4):467-490
In this paper, we develop a new approach to the design of direct numerical methods for multidimensional problems of the calculus of variations. The approach is based on a transformation of the problem with the use of a new class of Sobolev-like spaces that is studied in the article. This transformation allows one to analytically compute the direction of steepest descent of the main functional of the calculus of variations with respect to a certain inner product, and, in turn, to construct new direct numerical methods for multidimensional problems of the calculus of variations. In the end of the paper, we point out how the approach developed in the article can be extended to the case of problems with more general boundary conditions, problems for functionals depending on higher order derivatives, and problems with isoperimetric and/or pointwise constraints. 相似文献
56.
Gontarev S Shmanai V Frey SK Kvach M Schweigert FJ 《Rapid communications in mass spectrometry : RCM》2007,21(1):1-6
The complexity of the human plasma proteome is greatly increased by post-translational modifications. Besides physiological modifications, pathological conditions such as diabetes are responsible for adding to this complexity by producing advanced glycation endproducts (AGEs). When searching for specific biomarkers it is a prerequisite to reduce this complexity prior to analysis. To do this, agarose hydrogel was used to create a high-capacity affinity layer on the modified aluminum surface of MALDI (matrix-assisted laser desorption/ionization) targets. 3-Aminophenylboronic acid was immobilized via cyanogen bromide activation as a ligand for affinity sorption of glycated proteins, followed by their direct detection by MALDI. High protein capacity of prepared MALDI chips, efficient separation and low non-specific protein binding were demonstrated. The results show that phenylboronic acid modified hydrogels are very suitable for creating affinity surfaces for the high-throughput analysis of AGEs. 相似文献
57.
Acetoxy Meldrum's acid can serve as a versatile acyl anion equivalent in the Pd-catalyzed asymmetric allylic alkylation. The reaction of this nucleophile with various meso and racemic electrophiles afforded alkylated products in high yields and enantiopurities. These enantioenriched products are versatile intermediates that can be further functionalized using nitrogen- and oxygen-centered nucleophiles, affording versatile scaffolds for the synthesis of nucleoside analogues. These scaffolds were used to complete formal syntheses of the anti-HIV drugs carbovir, abacavir, and the antibiotic aristeromycin. 相似文献
58.
59.
Maksim Zhukovskii 《Discrete Mathematics》2012,312(10):1670-1688
In this article we study asymptotical behavior of the probabilities of some properties of Erd?s–Rényi random graphs . We consider the first-order properties and the probabilities for rational . The zero-one law in ordinary sense for these graphs doesn’t hold. We weakened the law by considering the formulas with quantifier depth bounded by a fixed number. To prove our results we used theorems on estimates for the number of extensions of small subgraphs in the random graph. Such an approach was first used by Spencer and Shelah in 1988. We also used our recent results from this area. 相似文献
60.
Davide Spinnato Bertrand Schweitzer‐Chaput Giulio Goti Maksim O&#x;eka Paolo Melchiorre 《Angewandte Chemie (International ed. in English)》2020,59(24):9485-9490
Reported herein is a visible‐light‐mediated radical approach to the α‐alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2‐based activation of alkyl halides and blue light irradiation. The resulting open‐shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl halides through a traditional two‐electron path. The mild reaction conditions allowed functionalization of the α position of ketones with functional groups that are not compatible with classical anionic strategies. In addition, the redox‐neutral nature of this process makes it compatible with a cinchona‐based primary amine catalyst, which was used to develop a rare example of enantioselective organocatalytic radical α‐alkylation of ketones. 相似文献