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61.
62.
A triangular lattice model for pattern formation by core-shell particles at fluid interfaces is introduced and studied for the particle to core diameter ratio equal to 3. Repulsion for overlapping shells and attraction at larger distances due to capillary forces are assumed. Ground states and thermodynamic properties are determined analytically and by Monte Carlo simulations for soft outer- and stiffer inner shells, with different decay rates of the interparticle repulsion. We find that thermodynamic properties are qualitatively the same for slow and for fast decay of the repulsive potential, but the ordered phases are stable for temperature ranges, depending strongly on the shape of the repulsive potential. More importantly, there are two types of patterns formed for fixed chemical potential—one for a slow and another one for a fast decay of the repulsion at small distances. In the first case, two different patterns—for example clusters or stripes—occur with the same probability for some range of the chemical potential. For a fixed concentration, an interface is formed between two ordered phases with the closest concentration, and the surface tension takes the same value for all stable interfaces. In the case of degeneracy, a stable interface cannot be formed for one out of four combinations of the coexisting phases, because of a larger surface tension. Our results show that by tuning the architecture of a thick polymeric shell, many different patterns can be obtained for a sufficiently low temperature. 相似文献
63.
Vera Ya. Popkova Mikhail Yu. Antipin Lyudmila E. Vinogradova Larisa A. Leites Yuri T. Struchkov 《Heteroatom Chemistry》1992,3(2):101-113
Perfluoro-2-methyl-2-pentene-thiocyanate-3 reacts with ammonia to give 2,4-diaminoperfluoro-4-methyl-2-pentenethiocyanate-3 ( 4 ) and 2-aminoperfluoro-4, 4-dimethyl-4,5-dihydro-5-ethylidene-1,3-thiazole ( 5 ). Compound 4 is kinetically stable and at 150°C under-goes rotational isomerization to afford the cyclic isomer 2-amino-4,4-bis(trifluoromethyl)-4,5-dihydro-5-(1-aminoperfluoroethylidene) -1,3-thiazole ( 6 ). Intramolecular cyclizations, resulting in the thiazolines 5 and 6 , proceed likewise via the Thorpe reaction. For compounds 4–6 , X-ray diffraction analyses were undertaken and IR spectra in solution and in solid state were investigated. It is supposed that a high kinetic preference for formation of 4 and the fact that it does not undergo spontaneous cyclization in ammonolysis stem from the NH …︁ N intramolecular hydrogen bonding between two amino groups. 相似文献
64.
Selective Synthesis of 2,5‐Diformylfuran by Sustainable 4‐acetamido‐TEMPO/Halogen‐Mediated Electrooxidation of 5‐Hydroxymethylfurfural 下载免费PDF全文
Dr. Vera P. Kashparova Dr. Victor A. Klushin Dr. Daria V. Leontyeva Prof. Dr. Nina V. Smirnova Prof. Dr. Victor M. Chernyshev Prof. Dr. Valentine P. Ananikov 《化学:亚洲杂志》2016,11(18):2578-2585
A new method was developed for the selective gram‐scale synthesis of 2,5‐diformylfuran (DFF), which is an important chemical with a high application potential, via oxidation of biomass‐derived 5‐hydroxylmethylfurfural (HMF) catalyzed by 4‐acetylamino‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl (4‐AcNH‐TEMPO) in a two‐phase system consisting of a methylene chloride and aqueous solution containing sodium hydrogen carbonate and potassium iodide. The key feature of this method is the generation of the I2 (co‐)oxidant by anodic oxidation of iodide anions during pulse electrolysis. In addition, the electrolyte can be successfully recycled five times while maintaining a 62–65 % yield of DFF. This novel method provides a sustainable pathway for waste‐free production of DFF without the use of metal catalysts and expensive oxidants. An advantage of electrooxidation is utilized in the preparation of demanding chemical. 相似文献
65.
Vera Yu Mishina Mikhail K. Gratchev Konstantin L. Anfilov Il'dar G. Mustafin Anna R. Bekker Edward E. Nifantyev 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The effective methods of phosphorylation of complex systems with specifically orientated in space hydroxyl groups, namely dianhydro-D-mannitol(A), -D-sor-bitol(B), cyclodextrines(C), and cellulose(D) (A-D, where R=H), have been elaborated. 相似文献
66.
Mathematical theory of optimization has found many applications in the area of medicine over the last few decades. Several
data analysis and decision making problems in medicine can be formulated using optimization and data mining techniques. The
significance of the mathematical models is greatly realized in the recent years owing to the growing technological capabilities
and the large amounts of data available. In this paper, we attempt to give a brief overview of some of the most interesting
applications of mathematical programming and data mining in medicine. In the overview, we include applications like radiation
therapy treatment, microarray data analysis, and computational neuroscience. 相似文献
67.
68.
MaxwellD. Cummings Jimmy Lindberg Tse‐I Lin Herman deKock Oliver Lenz Elisabet Lilja Sara Fellnder Vera Baraznenok Susanne Nystrm Magnus Nilsson Lotta Vrang Michael Edlund sa Rosenquist Bertil Samuelsson Pierre Raboisson Kenneth Simmen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2010,122(9):1552-1552
69.
Dr. Nina Erini Vera Beermann Martin Gocyla Manuel Gliech Dr. Marc Heggen Dr. Rafal E. Dunin-Borkowski Prof. Peter Strasser 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(23):6633-6638
Direct ethanol fuel cells are attractive power sources based on a biorenewable, high energy-density fuel. Their efficiency is limited by the lack of active anode materials which catalyze the breaking of the C−C bond coupled to the 12-electron oxidation to CO2. We report shape-controlled PtNiRh octahedral ethanol oxidation electrocatalysts with excellent activity and previously unachieved low onset potentials as low as 0.1 V vs. RHE, while being highly selective to complete oxidation to CO2. Our comprehensive characterization and in situ electrochemical ATR studies suggest that the formation of a ternary surface site ensemble around the octahedral Pt3Ni1Rhx nanoparticles plays a crucial mechanistic role for this behavior. 相似文献
70.
Maria J. Alves Vera C.M. Duarte Hélio Faustino António Gil Fortes 《Tetrahedron: Asymmetry》2010,21(15):1817-1820
Erythrose benzylidene-acetal 1,3-butadienes are studied as partners in Diels–Alder cycloadditions. A high diastereofacial improvement is found in cases where both the alcohol function is protected and a π–π interaction between the diene and dienophile is possible. Several competing factors have been studied independently in order to explain its influence on the selectivity of the cycloadditions. 相似文献