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11.
12.
Marina A. Khokhlova Marat O. Gallyamov Alexei R. Khokhlov 《Colloid and polymer science》2012,290(15):1471-1480
Chitosan macromolecules can be dissolved in water saturated with CO2 under high pressure, i.e. in carbonic acid. This unique biocompatible solvent with acidity regulated by the variation of applied CO2 pressure is rather promising for biomedical applications. In this work the main features of deposition of chitosan structures on the model substrate from solutions in this media were examined. After deposition on the mica surface, the obtained structures have been successfully visualised by atomic force microscopy (AFM). It has been found out that they adsorb as rather peculiar elongated objects with an average length of about 70?nm. Such conformations are believed to appear due to amphiphilic nature of chitosan semiflexible chains in agreement with recent theoretical findings. The well-defined geometry of the elongated monodispersed structures allows them to demonstrate some elements of liquid crystalline-like ordering. 相似文献
13.
B. A. Arbuzov N. A. Polezhaeva A. M. Polozov A. A. Mustafin E. I. Goldfarb A. A. Levin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The photochemical, thermo-catalytical and thermal reactions of diazoalkanes with dialkyl (thio)phosphites were studied. Thus, the photolysis of dimethyldiazomalonate and methyl-diazoacetate with dialkyl(thio)phosphites gives P-H insertion products only upon triplet-sensitized conditions (i), whereas diphenyldiazomethane gives P-H insertion products upon direct photolysis as well (ii). The investigation of 31 the reaction mechanism is based on CIDNP 31P method. The catalytical reactions (iii) are a convenient method of preparing (thio)phosphonates. 相似文献
14.
Pavel A. Tikhonov Nataliya G. Vasilenko Marat O. Gallyamov Georgii V. Cherkaev Viktor G. Vasilev Nina V. Demchenko Mikhail I. Buzin Sergey G. Vasilev Aziz M. Muzafarov 《Molecules (Basel, Switzerland)》2021,26(11)
New multiarm stars have been synthesized based on polylithium derivatives of high-generation carbosilane dendrimers. In the synthesis of multiarm stars based on the eighth-generation dendrimer, steric hindrances were observed even during the synthesis of a polylithium initiator. Subsequently, this led to chain transfer reactions between growing arms, as well as other side effects. As a result, dense nanogel formations with a higher tendency of ordering than in classical objects of this type were isolated from the reaction mixture. The study of the rheology of multiarm stars based on sixth-generation dendrimers made it possible to determine the activation energies of viscous flow in these objects, which makes it possible to consider them as objects with a macromolecular nature and a reptation flow mechanism. 相似文献
15.
Umbilic points--singular points of curvature characterized by a fractional topological charge q=+/-1/2--are the most numerous of all special points in the landscape of random optical fields (speckle patterns), outnumbering maxima, minima, saddle points, and optical vortices. To the best of our knowledge, we present the first experimental evidence that positive and negative umbilic points screen one another. Theory predicts that in the absence of screening the charge variance in a bounded region is proportional to the area of the region, whereas in the presence of screening the variance is drastically reduced and is proportional to the perimeter. Our data confirm this latter prediction and provide the first estimates of the screening lengths for umbilic points of the intensity and of the amplitude (field modulus). 相似文献
16.
S. A. Torosyan Yu. N. Biglova V. V. Mikheev F. A. Gimalova A. G. Mustafin M. S. Miftakhov 《Russian Journal of Organic Chemistry》2014,50(2):179-182
By reaction of 2-(acryloyloxyethyl) and (undecen-10-en-1-yl) methylmalonates with fullerene C60 in the system toluene-CBr4-DBU, and also by reaction of 2-(2,2-dichloroacetoxy)ethyl acrylate with C60 in the system toluene-DBU the corresponding products of fullerene monocyclopropanation were synthesized. 相似文献
17.
M.Sc. Johannes E. M. N. Klein Dr. Burkhard Miehlich Dr. Michael S. Holzwarth Prof. Dr. Matthias Bauer Dipl.‐Chem. Magdalena Milek Dr. Marat M. Khusniyarov Dr. Gerald Knizia Prof. Dr. Hans‐Joachim Werner Prof. Dr. Bernd Plietker 《Angewandte Chemie (International ed. in English)》2014,53(7):1790-1794
During the past 10 years iron‐catalyzed reactions have become established in the field of organic synthesis. For example, the complex anion [Fe(CO)3(NO)]?, which was originally described by Hogsed and Hieber, shows catalytic activity in various organic reactions. This anion is commonly regarded as being isoelectronic with [Fe(CO)4]2?, which, however, shows poor catalytic activity. The spectroscopic and quantum chemical investigations presented herein reveal that the complex ferrate [Fe(CO)3(NO)]? cannot be regarded as a Fe?II species, but rather is predominantly a Fe0 species, in which the metal is covalently bonded to NO? by two π‐bonds. A metal–N σ‐bond is not observed. 相似文献
18.
Petrova A. V. Khusnutdinova E. F. Mustafin A. G. Kazakova O. B. 《Russian Journal of Organic Chemistry》2020,56(1):174-176
Russian Journal of Organic Chemistry - Mannich reaction of N-propargyl triterpene aldimines obtained from betulonic and oleanonic aldehydes gave new aminoalkyl derivatives containing an... 相似文献
19.
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
20.
Fábio Roberto Chavarette José Manoel Balthazar Nelson José Peruzzi Marat Rafikov 《Communications in Nonlinear Science & Numerical Simulation》2009,14(3):892-905
The Fitzhugh–Nagumo (FH) mathematical model is considered a simplification of the Hodgkin–Huxley (HH) model. This paper analyzes the non-linear dynamics of the Fitzhugh–Nagumo (FN) mathematical model, and still presents some modifications in the governing equations of the system in order to transform it into a non-ideal one (taking into account that an energy source has limited power supply). We also developed an optimal linear control design and used Sinhas’s theory for the membrane’s action potential in order to stabilize the variation of this potential. 相似文献