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991.
Russian Journal of General Chemistry - Modified adsorbents for gas chromatography were prepared using a Cu(II) complex of a camphorsabstituted tetrapyrasinoporphyrazine. The thermal stability of... 相似文献
992.
Smolobochkin A. V. Gazizov A. S. Matylitskii K. V. Vagapova L. I. Burilov A. R. Pudovik M. A. 《Russian Journal of General Chemistry》2019,89(9):1934-1938
Russian Journal of General Chemistry - The acid-catalyzed reaction of {2-[1-(2,2-dimethoxyethyl)-3-(phenylcarboxamido)]ethyl}phosphonate or diethyl... 相似文献
993.
V. P. Medvedev V. V. Chapurkin A. V. Murzin M. A. Vaniev V. I. Frolova G. V. Medvedev I. A. Novakov 《Polymer Science Series D》2018,11(2):174-178
The curing of oligodienediol with a combined system consisting of a polyisocyanate and a (meth)acrylate-containing compound, which allows it to be structured with the polyisocyanate both at the terminal hydroxyl groups and double bonds due to the (meth)acrylate component, has been studied. The effect of the concentration of the (meth)acrylate component and a peroxide initiator to the degree of cross linking and strength properties of elastomers has been revealed. It has been shown that the participation of oligomer double bonds to form a vulcanization structure, creating the effect of “healing” defects from functional heterogeneity, allows one to increase the degree of cross linking and strength properties of polyurethanes. 相似文献
994.
An asymptotics of the error of interpolation of real constants at Chebyshev nodes is obtained. Some well-known estimates of the best approximation by simple partial fractions (logarithmic derivatives of algebraic polynomials) of real constants in the closed interval [?1, 1] and complex constants in the unit disk are refined. As a consequence, new estimates of the best approximation of real polynomials on closed intervals of the real axis and of complex polynomials on arbitrary compact sets are obtained.
相似文献995.
Studies have been carried out to increase the adhesion and heat resistance of insulating tape coatings based on chlorobutyl rubber applied on pipelines. It is shown that the synergistic effect of the growth of adhesion of chlorobutyl rubber to steel by the co-administration of the oligomer of 2,2,4-trimethyl-1,2-dihydroquinoline and polymeric petroleum resin is due to the increased interaction of the oligomer with chlorobutyl rubber under the action of a polymeric petroleum resin and the high adhesion of the oligomer to steel. 相似文献
996.
We put forth a dynamic computing framework for scale‐selective adaptation of weighted essential nonoscillatory (WENO) schemes for the simulation of hyperbolic conservation laws exhibiting strong discontinuities. A multilevel wavelet‐based multiresolution procedure, embedded in a conservative finite volume formulation, is used for a twofold purpose. (i) a dynamic grid adaptation of the solution field for redistributing grid points optimally (in some sense) according to the underlying flow structures, and (ii) a dynamic minimization of the in built artificial dissipation of WENO schemes. Taking advantage of the structure detection properties of this multiresolution algorithm, the nonlinear weights of the conventional WENO implementation are selectively modified to ensure lower dissipation in smoother areas. This modification is implemented through a linear transition from the fifth‐order upwind stencil at the coarsest regions of the adaptive grid to a fully nonlinear fifth‐order WENO scheme at areas of high irregularity. Therefore, our computing algorithm consists of a dynamic grid adaptation strategy, a scale‐selective state reconstruction, a conservative flux calculation, and a total variation diminishing Runge‐Kutta scheme for time advancement. Results are presented for canonical examples drawn from the inviscid Burgers, shallow water, Euler, and magnetohydrodynamic equations. Our findings represent a novel direction for providing a scale‐selective dissipation process without a compromise on shock capturing behavior for conservation laws, which would be a strong contender for dynamic implicit large eddy simulation approaches. 相似文献
997.
Mathematical Notes - Two approaches to systems of linear partial differential equations are considered: the traditional approach based on the generalized Fourier transform and the semigroup... 相似文献
998.
999.
New Effects in the Poly-N-Vinylcaprolactam/Titanium(IV) Oxides Nanocomposite System and Their Nature
Nanocomposites based on poly-N-vinylcaprolactam (PVC), characterized by different drying temperatures of aqueous PVC solution at 25°С (PVC25) and 40°С (PVC40), with titanium(IV) oxide nanoparticles (TONs) (η-phase (TP: TiO2 – x · mH2O) with a superstructure to the anatase structure and ordered solid solution with partial replacement of oxygen atoms in the η-phase with peroxo group O 2 2– (PP: TiO x (O2)2 – x · nH2O)) have been obtained for the first time and characterized by X-ray diffraction and IR spectroscopy. It is found that a common feature of TP/PVC and PP/PVC obtained by dry mixing and grinding is the decrease in the number of water molecules for TP and PP in the interlayer space of the structure and their attachment to the PVC amide groups; the differences are related to the specificity of PVC behavior in these systems: mechanodestruction of PVC in PP/PVC40 and different numbers of water molecules in PVC25 and PVC40. 相似文献
1000.
Yosselin Huentupil Patricio Chung Néstor Novoa A. Hugo Klahn Manuela E. Medina Jonathan Cisterna Iván Brito Andrés Rivera Rodrigo López-Muñoz Rodrigo Arancibia 《应用有机金属化学》2020,34(9):e5788
In the research of new compounds with multifunctional applications, heterobinuclear palladium (II) complexes based on organometallic dithiocarbazates (DTCZs) have been isolated. The organometallic DTCZ ligands of the general formula [{(η5-C5H4)-CH=NNHC(S)SCH3}]MLn [MLn = Re (CO)3 ( 2a ); Mn (CO)3 ( 2b ); FeCp ( 2c )] were prepared by the reaction between formyl organometallic precursors ( 1a−c ) with S-methyldithiocarbazate. Subsequently, a two-step reaction of 2a−c with: (i) K2[PdCl4] and (ii) PPh3 yielded heterobinuclear complexes [Pd{MLn(η5-C5H4)-CH=NNHC(S)SCH3}–(Cl)(PPh3)] [MLn = Re (CO)3 ( 3a ); Mn (CO)3 ( 3b ); FeCp ( 3c )]. All compounds were characterized by conventional spectroscopic techniques (infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis). In addition, the molecular structures of 2a , 2c and 3c were determined by single-crystal X-ray diffraction. The new palladium (II) complexes ( 3a−c ) were evaluated as antiproliferative agents against non-small cell lung cancer cells (H1299 cells). Complexes 3a and 3b containing cyrhetrenyl- and cymantrenyl-DTCZ ligands, respectively, were more active than their ferrocenyl analogue 3c . The activity was associated with the electron-withdrawing properties of the (η5-C5H4)M (CO)3 moieties and their better lipophilicity than that of the ferrocenyl analogue. In addition, we studied the capacity of metalloligands ( 2a−c ) and palladium (II) complexes ( 3a−c ) to remove methylene blue in water under UV–visible light irradiation. The results established that the complexes showed moderate efficiency and were less active than their corresponding free ligands. 相似文献