Siloxane–ethylene oxide–urethane block copolymers were synthesized by the interaction of oligosiloxane organodiols of the general formula HO(CH2)2OCH2Me2SiO–[SiR2O]n–SiMe2CH2O(CH2)2OH (R = Me, Et) and oligo(ethylene oxide) (OEO) (–CH2CH2O–)m with 4,4'-diphenylmethane diisocyanate. The copolymers obtained were studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The effect of the bulk composition on the composition and structure of the surface was established.

New polysiloxane–butylene oxide–urethane–ureas based on α,ω-bis[(3-aminopropyl)diethoxy]oligodimethylsiloxane, oligobutylene oxide, and fractions of dicyclohexylmethane 4,4'-diisocyanate (H12-MDI) with different contents of a trans-trans isomer have been synthesized. The mechanical properties of the films have been tested. It is established that the strength and relative elongation at break increase with the increasing content of the trans-trans isomer.

New network poly(siloxane–propylene oxide–urethane–ureas) based on α,ω-bis[(3-aminopropyl)diethoxy]oligodimethylsiloxanes, oligo(propylene oxide), and cycloaliphatic diisocyanates are synthesized. The resulting polymers are studied by differential scanning calorimetry and thermogravimetric analysis; their stress–strain characteristics are elucidated. These polymers are found to feature microphase separation and, consequently, two glass transition temperatures, defined by the chemical structures of the microphases. It is shown that an increase in the molecular weight and mass content of siloxane blocks leads to a decrease in the elastic modulus and tensile strength.

Characteristics of 27 subfossil spore–pollen spectra of recent plant communities in larch forests of Central Evenkia. Although larch forests dominate in the study region, the main components of the spectra are Betula sect. Betula and Alnus alnobetula subsp. fruticosa, whereas the proportion of Larix pollen is reduced relative to that of larch trees in the vegetation and ranges from 0.6 to 13.5%. The proportion of Picea pollen increases at sampling points where spruce is a component of tree stand. Pinus pollen is a foreign component of the spore–pollen spectra, and its proportion increases in phytocenoses where the tree layer is sparse or absent. Species characteristic of taiga forests and wetland and meadow habitats and indicators of disturbed grounds and burned-out areas have been identified, which will allow a more detailed and objective reconstruction of paleovegetation.

New evidences of the Holocene changes of landscapes in the Middle Protva River basin due to natural and anthropogenic factors are discussed. The studies are based on the multy-proxy analysis including paleolandscape reconstructions, detailed pollen analysis, materials of the large-scale landscape mapping and synthesis of archaeological and historical data. The results of paleobotanical studies and radiocarbon dating of the peat core from the Agrafenino peatland made it possible to reveal the key periods of vegetation changes and fire effects. The broadleaf deciduous forests with a small admixture of spruce spread to the Middle Protva River basin about 9,2 cal. years BP and were present in the dominant urochisches throughout the Middle Holocene, despite short-term warming and cooling cycles. An abundance of spruce increased significantly in the area at 2,5 cal. years BP when the climate became cooler and wetter; the sprucebroadleaf forests were formed to become the dominant vegetation type within watershed areas during the pre-agrarian period. From 6,2 to 4,2 cal years BP frequent and intense forest fires affected the study area, causing the destruction of broadleaf forests and expansion of secondary birch-pine woodlands. The direct anthropogenic indicators in pollen assemblages are absent, thus it is possible to suggest that during the period the fires were causes mainly by climatic factors. The study area was developed by humans since Mesolithic. However till the 17 th century landscape complexes of watershed areas underwent no significant anthropogenic transformation unlike the river valley landscapes.

Polyblock butylenoxide-siloxaneurethane elastomers with a specific chemical structure defined by a changed content of butylene oxide and dimethylsiloxane prepolymers with NCO terminal groups are prepared by a directed one-step synthetic procedure. The synthesis is carried out at room temperature in methyl ethyl ketone without catalysts and chain extenders using aromatic diamines as crosslinking agents. The proposed method allows one to obtain copolymers with a different structure. Such copolymers have high deformation and strength characteristics and are promising in medicine.

The morphology and thermal and mechanical properties of siloxane urethane block copolymers based on oligosiloxane- and oligoalkylene diols are investigated. The dependence of morphology on the conditions of synthesis is studied via atomic force microscopy and scanning electron microscopy.

Structures of amorphous polyether urethanes modified with oligomeric organosilicon blocks are studied via AFM, SEM, and TEM. The main structural unit of the investigated polymers is found to be a globule. The effect the silicon modifier has on the polyether urethane structure is determined.

Методами АСМ, СЭМ и ПЭМ изучена структура аморфных полиэфируретанов, модифицированных олигомерными кремнийорганическими блоками. Показано, что структурным элементом изученных полимеров является глобула. Установлено влияние кремнийорганического модификатора на структуру полиэфируретанов.

This article provides information about the depositories of parasitic worms in the scientific institutes and museums in the United States, Japan, and Europe (the total number of samples and the availability of types of helminths from various classes), as well as information on the availability of electronic catalogues of the collections in the continental, national, and regional centers for collective use. The extent of this material has determined the necessity of creating digital collections and libraries that would represent a new form of storing, displaying, and exchanging information for scientific research. An analysis was performed of the current state of approaches and methods of development of the specialized information retrieval system (IRS) and databases (DBs) on the parasitic worms in Russia on the basis of a common conceptual data model, taking into account their local use (as desktop systems of database management) and access by scientists worldwide via the Internet.

Методами АСМ, СЭМ и ПЭМ изучена структура аморфных полимеров – полисилоксан-карбонат-уретанов. Показано, что структура полимера зависит от природы растворителя, используемого для формирования пленки.

The structure of amorphous polysiloxane carbonate urethanes is studied by AFM, SEM, and TEM. It is found that the polymer structure depends on the nature of solvent used for film casting.

Методами атомно-силовой (АСМ) и сканирующей электронной микроскопии (СЭМ) изучена структура силоксан-уретан-этиленоксидных блок-сополимеров. Методом рентгеновской дифракции определена степень кристалличности сополимеров. Установлена корреляция полученных результатов.

Катионной полимеризацией гексаэтилциклотрисилоксана в присутствии бис-(?-оксиэтоксиметил)тетраметилдисилоксана впервые синтезированы олигодиэтилсилоксандиолы с концевыми ?-оксиэтоксиметильными группами. В качестве катализатора полимеризации применяли серную кислоту или катионит КУ-23. Установлено, что наряду с олигодиэтилсилоксандиолами образуются продукты перегруппировки диэтилсилоксановой цепи в виде октаэтилциклотетрасилоксана и высших циклов. При реакции дикалиевых солей олигодиэтилсилоксандиолов с хлорсиланом формулы ClSi(CH3)2CH2O(CH2)2OCOCH3 получаются олигомеры с концевыми ацетокси-группами, которые также содержат октаэтилциклотетрасилоксан и высшие циклы.