605 research outputs found
Catalytic degradation of polyethylene in the presence of synthetic aluminosilicates
Degradation of polyethylene in the presence of synthetic amorphous aluminosilicates as catalysts to form petroleum-like hydrocarbons was studiedyesBS
Reproductive potential of yellow water-lily (Nuphar lutea) in the conditions of lake ecosystems
Nuphar lutea (L.) Sm. (Nymphaeaceae Salisb.) belongs to the category of highly active cenose-forming plants in water bodies and water flows. The material for study of morphological peculiarities and seed productivity of the fruits of this species was collected mainly in the lake ecosystems of the Central Part of European Russia and Republic of Belarus. In the study we used biomorphological and ontogenetic approaches. Seed productivity was surveyed by direct count of number of seeds in the fruit. By abundance (in descending order), the significant reliable inter-lake differences in a number of morphological parameters of the fruit fall into the following sequence: number of rays of stigma of fruit (in six pairs of lakes) > length of fruit (in four pairs of lakes) > diameter of the stigma of fruit (in three pairs of lakes) > diameter of fruit (in two pairs of lakes) > length of the neck of the fruit (in one pair of lakes). Intra-regional differences in certain morphological parameters of fruits (by number of rays of stigmas) were most notably manifested only in the Belarus lakes which are similar by trophic status. All the differences in the fruits’ morphology could be due to differences in the habitat by the amount of nutrients in water and soil. The amount of seed productivity of the fruits from N. lutea varies broadly. Analysis of this parameter depending on the character of soils in which the plants grew indicated reliable results only in the case of muddy (296 ± 81) and sandy soils (179 ± 13). We determined that distribution of generative diasporas of N. lutea across large distances is related not only to presence of floating ability in the seeds, but also the “multi-step” process of their release: first – mericarps from fruits, and then seeds from mericarps. In the experimental conditions, most seeds directly sunk to the bed (70%) and the rest continued to float on the surface of the water during a month. Low germination of the seeds of the water-lily in the laboratory conditions (4–6%) with use of different means and terms of dry stratification was due to the fact that they have an organic morphophysiological intermediate type of rest. Having such a mechanism causes portioned and prolonged germination, allowing the species to survive in non-favourable conditions and accumulate generative diaspores in the soil. Despite the fact that the initial stages of ontogenesis in the laboratory and natural conditions have no significant differences, we found polyvariance in their tempo of development. First of all, this is related to different dates of transition of the plant from one age state to another. In the case of N. lutea, one should also note the morphological polyvariance of ontogenesis related to change in morphologic characteristics of plants depending on the water level. The obtained results give a more complete picture of the peculiarities of generative reproduction of N. lutea, necessary for understanding the ecosystem role of this plant and its impact on biological processes in water bodies
Effect of metal cations on the microstructure of sol-gel-synthesized silica
The effect of small doping additions (ten metal cations) on the structural characteristics of the solgel- synthesized silicas was evaluated by the SAXS method. Doping with cobalt, cerium, and silver cations led to separation of metal compounds as single phases. All the tested cations affected the radius of gyration and the fractal dimension of the resultant silica
Time management and professional identity of students of pedagogical universities
Topicality of the problem under research is stipulated by the necessity of personal characteristics consideration in the process of organization of educational and vocational activities of the future teachers in the conditions of educational medium, which sets high requirements to the students' time competence. The aim of the article is to study the influence of time management peculiarities on the components of students' professional identity. The primary research method applied was psychodiagnostic testing with further statistical data processing, enabling quantitative assessment of formedness of time competence and professional identity in students of a pedagogical university, as well as establishing the interaction character of the phenomena of interest. Research results: in the article peculiarities of students time management within different stages of professional identity are presented, and the interconnection between time competence and professional identity components is considered. Based on empirical data, there can be drawn a conclusion that time competence development will facilitate formation of professional identity for the future professionals. Received results can find practical implementation in development of programs for psychological follow-up of professional formation of student's identity in the system of university education. © 2016 Lebedeva et al
Evaluative Potential of Lexemes — Representatives of Concept TRUE in Russian
The study of the evaluative potential of the concept TRUTH in the Russian language picture of the world has been carried out. The results of the analysis of the use of the word true in the role of a qualitative adjective with evaluative semantics and the word truly in the role of a qualitative adverb with the semantics of the degree of manifestation of a property, feature or action / state are presented based on the materials of the Russian National Corpus and the authors’ own Internet monitoring in the Russian-speaking segment of the Internet. It is shown that in the total semantic content of the concept TRUTH, two semantic layers of its conceptual content in the modern Russian are realized: correspondence to reality; compliance with the norm in the world of people, the highest ideal. The following varieties of uses of the qualitative adjective true and the qualitative adverb truly as a secondary assessment based on the general meaning of “corresponding to the ideal in the world of norms and values of the speaker” were found: the meaning is “ideal, exemplary, perfect”; the meaning is “full, reached / brought to the maximum degree of manifestation of the entity named by the defined word” and the meaning of a strong degree of manifestation of something. It is concluded that the words true and truly embody the subjective moral and value ideas of native speakers about how it should be in the world of human relations, and not about “how it really is”
Photodecolourization of congo red dye in presence of Ni3+ layered double hydroxide
Layered double hydroxide containing Ni3+ (Mg/AlNi-LDH) was successfully synthesized by co-precipitation in an oxidizing media. The resulted product was characterized using X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry. The activity of Mg/AlNi-LDH in the process of photodegradation of Congo red dye using UV light irradiation was evaluated. The initial rate of photodegradation of the dye in the presence of LDH is 1.6 times higher than that of UV irradiated solution. The kinetic data obtained for photodegradation process can be adequately described by pseudo-first-order kinetic model. The presence of Mg/AlNi - LDH leads to increased photodegradation yield compared to destruction only by UV irradiatio
Influence of various factors on chemical decomposition of oxyethylated isononylphenols
Oxidative decomposition of difficultly biodegradable nonionic surfactants, oxyethylated phenols with various degrees of oxyethylation (Neonols AF 9-6, 9-10, 9-12), was examined. The initial rate and extent of the oxidation depend on the degree of oxyethylation, anion of the iron salt added, and temperatureye
Effect of synthesis method on properties of layered double hydroxides containing Ni(III)
Unstable oxidation state +3 of nickel can be stabilized in the structure of layered double hydroxides, the resulting crystallinity and properties being dependent on the synthesis method. Three different wet chemical methods (co-precipitation at variable pH, co-precipitation followed by hydrothermal treatment, co-precipitation with icrowave treatment) were used to synthesize Mg/Ni-Al layered double hydroxides containing triply charged nickel cation
Catalytic conversion of polyolefins in the presence of MCM-41 type mesoporous materials
The catalytic activities of mesoporous H-MCM-41 aluminosilicates of different compositions in degradation of polypropylene and a polypropylene-polyethylene mixture into gasoline-range fraction hydrocarbons were compared. A higher yield of the target products (86 wt %) was observed for the sample with a lower aluminum conten
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