排序方式: 共有34条查询结果,搜索用时 296 毫秒
1.
New oscillation and nonoscillation criteria are established for the equation
,where p :]1,+[ R is the locally integrable function. These criteria generalize and complement the well known criteria of E. Hille, Z. Nehari, A. Wintner, and P. Hartman. 相似文献
2.
It is proved that algebraic and topological K-functors are isomorphic on the category of stable generalized operator algebras which are K
i
-regular for all i > 0. 相似文献
3.
Coulomb Sturmians are obtained in prolate spheroidal coordinates by separation of variables in the Schrödinger equation and direct solution of the appropriate one-dimensional equations. Molecular orbitals are expressed as linear combinations of the introduced Coulomb Sturmians and some low-lying energy terms and corresponding wave functions are calculated for one-electron diatomic molecules. It is shown that similarity of the one- and two-centre orbitals in spheroidal coordinates, combined with completeness and good convergence properties of Coulomb Sturmians, substantially speeds up convergence and makes the calculated results closer to the exact ones. Application of the elaborated calculating scheme for diatomic many-electron molecules is discussed. 相似文献
4.
5.
Virgil Percec Ernesto Ramirez‐Castillo Anatoliy V. Popov Luis A. Hinojosa‐Falcon Tamaz Guliashvili 《Journal of polymer science. Part A, Polymer chemistry》2005,43(10):2178-2184
Sodium dithionite in the presence of NaHCO3 in water acts as a single‐electron‐transfer agent and facilitates the single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization (SET–DTLRP) of acrylates initiated with iodoform at room temperature. The resulting α,ω‐di(iodo)polyacrylates can be used as macroinitiators for the SET–DTLRP of other acrylates. Ultrahigh‐molar‐mass poly(tert‐butyl acrylate) can be synthesized via the SET–DTLRP of tert‐butyl acrylate and has a very low weight‐average molecular weight/number‐average molecular weight ratio of 1.15. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2178–2184, 2005 相似文献
6.
Eutectic mixtures as a green alternative for efficient catalyst recycling in atom transfer radical polymerizations
下载免费PDF全文
![点击此处可从《Journal of polymer science. Part A, Polymer chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pedro Maximiano Patrícia V. Mendonça Madson R. E. Santos João R. C. Costa Tamaz Guliashvili Arménio C. Serra Jorge F. J. Coelho 《Journal of polymer science. Part A, Polymer chemistry》2017,55(3):371-381
A new solvent mixture, based on ethanol/reline (EM: eutectic mixture), was investigated for the supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of methyl acrylate (MA) near room temperature, for the first time, affording complete catalyst recovery and reuse. The kinetic results revealed that the polymerizations were controlled, with polymers having narrow molecular weight distributions (? < 1.2). The “living” character of the resultant PMA was confirmed by the synthesis of a well‐defined PMA‐b‐PBA block copolymer. Remarkably, it was demonstrated that the Cu(0)/CuBr2/Me6TREN (Me6TREN: tris[2‐(dimethylamino)ethyl]amine) could be recovered from the final reaction mixture and reused for new successful SARA ATRP of MA, suggesting that the reported system could be very attractive from both the economic and environmental perspectives. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 371–381 相似文献
7.
Ambient temperature SARA ATRP for meth(acrylates), styrene,and vinyl chloride using sulfolane/1‐butyl‐3‐methylimidazolium hexafluorophosphate‐based mixtures
下载免费PDF全文
![点击此处可从《Journal of polymer science. Part A, Polymer chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
8.
R. V. Yakushin V. A. Kolesnikov V. A. Brodskiy E. N. Ofitserov A. V. Chistolinov A. V. Perfil’eva I. N. Solov’eva G. I. Kandelaki 《High Energy Chemistry》2018,52(2):183-188
The effect of dielectric-barrier discharge plasma treatment on the valence state of metal ions in aqueous solutions of manganese, iron, cobalt, and nickel (Mn, Fe, Co, Ni) salts has been studied. The efficiency of recovery of sparingly soluble compounds of transition metals during the treatment of model solutions in a plasma reactor designed by the authors has been evaluated. The possibility of hydrogen peroxide formation in water by barrier discharge treatment has been shown, and the change in the redox potential of the system has been analyzed. 相似文献
9.
Mdzinarashvili Tamaz Khvedelidze Mariam Shekiladze Eka Koenneke Aljoscha Schneider Marc 《Journal of Thermal Analysis and Calorimetry》2020,139(2):1131-1140
Journal of Thermal Analysis and Calorimetry - The stabilizer, which is used during the preparation of Poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs), is of great importance for particle... 相似文献
10.
This paper is the continuation of [1] in which complex symmetries of distributions and their covariance operators are investigated. Here we also study the most general quaternion symmetries of random vectors. Complete classification theorems on these symmetries are proved in terms of covariance operator spectra. 相似文献