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1.
We give combinatorial proofs that certain families of differences of products of Schur functions are monomial-positive. We
show in addition that such monomial-positivity is to be expected of a large class of generating functions with combinatorial
definitions similar to Schur functions. These generating functions are defined on posets with labelled Hasse diagrams and
include for example generating functions of Stanley's (P,ω)-partitions.
T.L. was supported in part by NSF DMS-0600677. 相似文献
2.
Protective properties of polyaniline coatings electrochemically deposited in the galvanostatic mode from oxalic acid solutions onto the surface of low-carbon steel were studied by measuring polarization curves. 相似文献
3.
The behaviour of the doubletn-d scattering phase shift 2(k) at energies close to the three-particle threshold is studied analytically and numerically. The scattering parameters possess an anomaly associated with the low energy of the singletN-N virtual state. The anomaly manifests itself both as a bend in the energy dependence of the functionk cot(Re 2) in the range around 0.5 MeV and in the nonstandard behaviour of the break-up cross section near the threshold. 相似文献
4.
5.
A. A. Pud G. S. Shapoval V. K. Skubin N. V. Kondrashova Yu. V. Kontsur G. M. Tel'biz 《Theoretical and Experimental Chemistry》1989,25(6):653-658
A study has been made of the electrochemical reductive breakdown (ECRB) of solid-phase chlorinated butyl rubber (CBR). It has been established that CBR does not accept electrons under conditions of fast sweep of electrode potential; however, with prolonged cathodic polarization of the substrate at the polymer/cathode/solution three-phase boundary, it undergoes reduction and subsequent chemical conversion, including intermolecular cross-linking and breakdown of the macromolecules. The rate of ECRB of the CBR depends on the potential and materials of the cathode, and also on the nature of the solvent. In a aprotic medium, the process of CBR breakdown leads to the formation of long polyconjugated structures that color its surface black in the vicinity of the three-phase boundary. In an aqueous medium, no such color is observed, but the products of ECRB are found to contain conjugated double bonds with a shorter conjugation chain than in the case of the aprotic medium. It has been established that he starting reaction in ECRB of CBR is reduction of the C-Cl bond and subsequent elimination of Cl–.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 6, pp. 710–715, November–December, 1989. 相似文献
6.
A. A. Pud S. P. Rogal'skii G. S. Shapoval 《Theoretical and Experimental Chemistry》1998,34(6):348-351
The electrochemical properties of organic mono- and polycarbonates have been investigated by polarography for the first time.
Electrochemical reduction of the carbonate group occurs by a one electron mechanism. The process is limited by diffusion of
the carbonate to the cathode surface. Aliphatic carbonates are reduced at a more negative potential than aromatic carbonates.
The rate of electrochemical reduction of the carbonate group is considerably decreased on going from low-molecular to high-molecular
carbonates.
Institute of Bioorganic and Petroleum Chemistry, National Academy of Sciences of Ukraine, 1 Murmanskaya ul., Kiev 253094,
Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 34, No. 6, pp. 376–379, November–December, 1998. 相似文献
7.
G. S. Shapoval V. F. Gromovaya I. E. Mironyuk 《Theoretical and Experimental Chemistry》1996,32(2):108-111
The influence of ascorbic acid on the stepwise process of reduction of oxygen (molecular oxygen, hydroxyl radicals, hydrogen peroxide) on electrodes of iron, copper, and platinum was established. Hypotheses with regard to the mechanism of the antioxidant action of ascorbic acid in biosystems were advanced.Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, I Murmanskaya Ulitsa, 252660 Kiev-94, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 2, pp. 124–127, March–April, 1996. Original article submitted June 23, 1995. 相似文献
8.
Svitlana V. Shishkina Irina S. Konovalova Pavlo V. Trostianko Anna O. Geleverya Sergiy M. Kovalenko Natalya D. Bunyatyan 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(6):822-832
The polymorphic study of 3‐(3‐phenyl‐1H‐1,2,4‐triazol‐5‐yl)‐2H‐1‐benzopyran‐2‐one, C17H11N3O2, was performed due to its potential biological activity and revealed three polymorphic modifications in the triclinic space group P, the monoclinic space group P21 and the orthorhombic space group Pbca. These polymorphs have a one‐column layered type of crystal organization. The strongest interactions between the molecules of the studied structures is stacking between π‐systems, while N—H…N and C—H…O hydrogen bonds link stacked columns forming layers as a secondary basic structural motif. C—H…π hydrogen bonds were observed between neighbouring layers and their role is the least significant in the formation of the crystal structure. Packing differences between the polymorphic modifications are minor and can be identified only using an analysis based on a comparison of the pairwise interaction energies. 相似文献
9.
Svitlana V. Shishkina Igor V. Ukrainets Olga V. Vashchenko Natali I. Voloshchuk Pavlo S. Bondarenko Lidiya A. Petrushova Galina Sim 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(1):69-74
The title benzothiazine‐3‐carboxamide, C17H16N2O4S, crystallized in two enantiomorphic crystal forms with the space groups P32 and P31 despite the absence of a classic stereogenic atom. The molecular structures are mirror images of each other. Only one sulfonyl O atom takes part in intramolecular hydrogen bonding as a proton acceptor and this atom is different in the two enantiomorphic structures. As a result, the S atom becomes a pseudo‐stereogenic centre. This fact is worth taking into account due to the different biological activities of the enantiomorphic forms. One form possesses a high analgesic activity, while the other form revealed a high anti‐inflammatory activity. 相似文献
10.