A number of thermoreactive oligomers was obtained
via the Michael interaction of molar excesses of
hexamethylene-bis-maleimide with 5,5’-bisbenzotriazoles
in melt. The structure of them was
proved by the 13C spectroscopy method. The one-step
synthesis in melt, without by-products evolution, in
absence of organic solvents, additional reagents, and
catalysts is the more acceptable in point of view of
technology (a finished reaction product does not
require any purification). The process itself is the
nucleophile addition across double bond, and so it can
be attributed to the atom-saving technologies.
According to data of the dynamic scanning calorimetry
(DSC) and the thermogravimetry (TG), oligomers fuse
at 130.8–135.6 °С, cross-link at 185–250 °С, and begin
their thermal destruction in air at temperatures of 400–
420 °С. The tensile strength at shear of the glued joints
on base of oligomers (steel plates overlapped) is 14.2–
23.7 MPa (142–237 kgf/cm2
). The positive effect from
the introduce of 5,5’-bis-benzotriazolyl fragments into
structure of bismaleimide thermoreactive oligomers on
strength of the glued joints between metal plates was
revealed
The article attempted to characterize the contribution of the first Directors of the Chechen-
Ingush state pedagogical/teaching
Institute - F. E. Bykova and A. P. Efleeva in the formation of higher pedagogical school in Checheno-Ingushetia in 1938-1951
In the present article, we have described data of comparative ampelography of biometric evaluation of leaf parameters of the three table grapes: Preobragenie, Victor and Jubiley Novocherkasska, widespread in the amateur and farming areas of Russia and the Ukraine
Currently, the problem of using a "client-server" technology for database is up-to-date. Among its advantages it has a high degree of security, the ability to work with multimedia and non-standard data, simple tastes to the hardware power client stations, the territorial independence of work in both local and wide area networks. The article presents the concept and describes the implementation of a client-server information system configuration databases based on plug-ins that enable flexible, fast and efficient to make changes to an existing application for working with databases. This approach solves the problem of using one program to connect to multiple databases
The results of the constructional and technological parameters optimization of inertia-dressing type threshing and separating device used by the combine for industrial crops harvesting are given in the article
The article presents results of studying total content
of titanium in both not fertilized and systematically
fertilized black leached soil. Science-based system of
fertilizer crop rotation allows solving problems of
sufficient balance of nutrients in the system of "soilplant-fertilizer",
increasing the quantity and
improving the quality of the crop. At the same time,
their application is active influence on the natural
environment. In the soil, there is an input of a large
set of chemical elements come along with fertilizers.
In addition, due to their physiological pH or
alkalinity, fertilizers are capable to affect the physical
and chemical properties of the soil. The use of
mineral fertilizers in scientifically based doses on the
fields of crop rotation for 33 years virtually has no
impact on the content of titanium in leached
Chernozem. In the arable layer its number increased
only by 2.1 %, and in subsurface - it is the same as in
the crop without fertilizer. Enrichment of topsoil with
titanium is due to desilication of rocks during
weathering. Due to the low solubility of titanium
minerals, they remain in the place longer, and
therefore, the content of the element in the soil
increases. As you know, fertilizers applied to the
fields of crop rotation, increase the intensity of the
biological cycle of substances and thereby enhance
the process of destruction of the parent rocks
The revolutionary changes which have occurred owing to transformational market reforms have led to necessity of basic changes of the theoretical and methodological postulates, concerning organization and management of agrarian manufacture and business
In the history of Russia, the year of 2012 opens the report of the new period of its development. The constitutional transformations begun in the end of 80’s of the last century, they find new directions and are filled with new maintenance, commensurable with worldwide processes. Sights at the tendencies formed in new conditions with orientation on succession in development of the previous transformations are offered in this article
Features of a survival of self-sowing and undergrowth of oak (Quercus robur) under crones of a parent forest stand are considered
An original design of a piston press, performing material pressing, due to case design tapered piston and the matrix, has been proposed for the first time