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排序方式: 共有1395条查询结果,搜索用时 9 毫秒
1.
N. A. Sivov A. I. Martynenko G. N. Bondarenko M. P. Filatova E. Yu. Kabanova N. I. Popova A. N. Sivov E. B. Kruts’ko 《Petroleum Chemistry》2006,46(1):41-59
Structures and compositions of the monomers guanidine acrylate and guanidine methacrylate, their homopolymers, and copolymers with diallyldimethylammonium chloride enriched in acrylate comonomer units were determined. It was shown that ampholytic copolymers, owing to their ionic nature, contained comonomeric guanidine acrylate or methacrylate units and diallyldimethylammonium chloride units, as well as the acrylate comonomer with the diallyl counterion and polymeric acrylate and diallyl ion pairs. It follows from IR and 1H NMR data that guanidine methacrylate has the same structure (with two hydrogen bonds) in the solid state and in solutions. Guanidine acrylate structures in the solid state and in dimethylsulfoxide are identical and analogous to guanidine methacrylate structure in this solvent. In water, the guanidine acrylate structure has another type of hydrogen bonding (with one hydrogen bond, where the proton is shifted toward the guanidine group). These features of hydrogen bonding of guanidine acrylate and guanidine methacrylate are also retained in their homopolymers and copolymers with diallyldimethylammonium chloride. It was shown that the thermal stability of the copolymers was higher than that of their homopolymers, confirming the formation of intramolecular ion pairs of oppositely charged units of ampholytic copolymers. Moreover, the thermal stability of guanidine methacrylate-diallyldimethylammonium chloride copolymers is higher than that of guanidine acrylate-diallyldimethylammonium chloride copolymers. 相似文献
2.
V. S. Bessmertnyi N. I. Min’ko P. S. Dyumina V. P. Krokhin S. V. Semenenko M. A. Lipko 《Glass and Ceramics》2005,62(11-12):386-387
A technology for the synthesis of synthetic minerals (using the example of spinels) using a low-temperature plasma flame is developed. The diagnostic properties of spinels are identified. 相似文献
3.
Studies on the influence of anthracene coal extracts on the carbonization process of medium- and high-rank coals were undertaken. Extracts from flame coal (Int. Class. 900) and gas-coking coal (Int. Class. 632) were used as additives. The blends prepared from the examined coals and the extracts exhibited better coking properties than the parent coals. The addition of extract to the coals gave an increase in the microstrength of the resultant cokes. The effects of co-carbonization of coking coals with extracts were increases in the size of the optical texture as well as in the degree of structural ordering of cokes. In the co-carbonization of semicoking coal with addition of coal extracts, a reduction in the size of the anisotropic units and a decrease in the crystallite height of cokes were observed. No modification of the basic anisotropy of coke from anthracite by coal extract was observed. With increasing extract content in anthracite/extract blends there was an increase in the degree of structural ordering of co-carbonization products. Extract addition was unable to modify the behaviour of fusinite. Based on the results of investigation of the influence of coal extracts on the carbonization of different-rank coals, a division of coals according to the modification of the optical texture of coke is given. 相似文献
4.
5.
I. Yu. Grebennikov V. I. Gun’ko A. Ya. Dmitrishin L. I. Onishchenko S. O. Toporov T. A. Feshchuk 《Russian Electrical Engineering》2007,78(1):23-25
Methods for cleaning commercial T-1500 dielectric oil with different adsorbents are studied. The oil is intended for impregnation of high-voltage pulse capacitors with film dielectric. 相似文献
6.
Yu. E. Berezkin S. A. Borinskaya A. V. Kuznetsova O. V. Sen’ko 《Pattern Recognition and Image Analysis》2009,19(4):630-633
This work is devoted to the development and substantiation of intellectual data mining as applied to studying folklore and
mythological traditions. The approach is based on use of the functions of distance between traditions. The examples of application
of the methods developed to investigate the interrelation between folklore traditions of the American continent are considered. 相似文献
7.
A. B. Aleskandrov M. S. Vladimirov L. A. Goncharova N. S. Konovalova G. I. Orlova N. G. Peresad’ko N. G. Polukhina N. I. Starkov M. M. Chernyavskii A. O. Shchelkanov 《Instruments and Experimental Techniques》2007,50(4):469-473
A technique for measuring the charges of relativistic nuclei in thick emulsion layers irradiated in a longitudinal direction is described. This technique has been implemented on the PAVICOM completely automated facility at the Lebedev Physical Institute. The calibration curves for relativistic nuclei with Z > 3 are presented. The advantages of this technique are demonstrated using charge measurements of 28Si nuclear fragments as an example. 相似文献
8.
We propose a method for constructing ensembles of regression models and perform its theoretical and experimental analysis. 相似文献
9.
10.
V. P. Grigor’ev S. P. Shpan’ko V. V. Boginskaya E. V. Plekhanova 《Protection of Metals and Physical Chemistry of Surfaces》2010,46(1):123-128
The residual protective effect of n-component mixtures of o-oxyazomethine derivatives at the corrosion of iron in 1 M H2SO4 decreases with time and an increase in temperature of the environment and increases with an increase in the polarity of substituent groups in the molecules and the inhibitor concentration in the solution. These regularities are interpreted based on the principle of the linear free-energy relation. 相似文献