The analysis of the ultraviolet induced transformation of the thermal decomposition spectra of the monomer of the submicrometer layers of polymethylmethacrylate and its composite with fullerene C
60
...for different fullerene concentrations and irradiation doses has been carried out. Formation of the new decomposition stages in the spectra has been interpreted by the binding between C
60
and side ester groups of polymethylmethacrylate.
The formation of decomposition products of macromolecules was found upon friction of polyoxymethylene against polyoxymethylene in the vacuum of mass-spectrometer . Their composition is shown to be ...different from that of the products of thermal decomposition of polyoxymethylene. It is shown that the formation of decomposition products is accompanied by the transition of the friction force from low to high level. The effect has been interpreted by the mechanical rupture of macromolecules upon friction. Quantitative parameters of the process have been discussed.
Orthology, refining the concept of homology, is the cornerstone of evolutionary comparative studies. With the ever-increasing availability of genomic data, inference of orthology has become ...instrumental for generating hypotheses about gene functions crucial to many studies. This update of the OrthoDB hierarchical catalog of orthologs (http://www.orthodb.org) covers 3027 complete genomes, including the most comprehensive set of 87 arthropods, 61 vertebrates, 227 fungi and 2627 bacteria (sampling the most complete and representative genomes from over 11,000 available). In addition to the most extensive integration of functional annotations from UniProt, InterPro, GO, OMIM, model organism phenotypes and COG functional categories, OrthoDB uniquely provides evolutionary annotations including rates of ortholog sequence divergence, copy-number profiles, sibling groups and gene architectures. We re-designed the entirety of the OrthoDB website from the underlying technology to the user interface, enabling the user to specify species of interest and to select the relevant orthology level by the NCBI taxonomy. The text searches allow use of complex logic with various identifiers of genes, proteins, domains, ontologies or annotation keywords and phrases. Gene copy-number profiles can also be queried. This release comes with the freely available underlying ortholog clustering pipeline (http://www.orthodb.org/software).
The morphotypic variability in the masticatory surface of the third upper molar has been studied in six rock vole species. In total, 49 morphotypes have been identified. Based on the morphotypes ...identified on the left and right maxilla, epigenetic landscape models turning out to be similar have been constructed for the studied species. Each model is based on two most frequent morphotypes. The highest proportion of asymmetric animals (except Tuva voles) has exactly these morphotypes. The remaining morphotypes may be considered within the epigenetic landscape model as intermediary and as recording longer transitions between the two main morphotypes.
A wide range of complementary research technique - XRD, SEM, TEM, MFM, HV, and low temperature heat capacity, in situ neutron diffraction, resistivity, vibrating sample magnetometry, internal ...friction, dilatometry, and differential scanning calorimetry - is applied to study structure and phase transitions at heating and cooling of two Fe–Ga functional alloys with 25 and 27 at.% Ga. Using high resolution neutron diffraction, it is unambiguously proven that the initial state of both as-cast samples at room temperature is the D03 phase which results from ordering of the high temperature A2 phase during cooling. Heating of as-cast samples and their subsequent cooling leads to a cascade of phase transitions which change the samples’ structural, mechanical and physical properties. These transitions and properties are discussed in the paper. Transition from metastable D03 to stable L12 phase at heating or isothermal annealing leads to significant changes in macro (grain size) and micro (ordering) structure, hardness and magnetic properties (magnetostriction, magnetization). According to our structural studies (ND, XRD), composition Fe-25.5 at.%Ga below ∼600 °C belongs to a single phase (L12) range of the equilibrium phase diagram, while in the Fe-26.9Ga alloy some amount of the D019 phase is also present.
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•Phase transition for two galfenol alloys were studied during heating and cooling.•A complementary research technique is applied to the study.•Electrical-resistivity is used for the first time to characterize phase transitions.•The initial state of the two alloys consists of D03 and B2 ordered clusters.•Phase transition from metastable D03 to stable L12 changes magnetic properties.
The evolution of the microstructure and mechanical properties of deformed sheets made of a new Al–4Cu–2.7Er alloy has been studied in the course of homogenization and annealing. The structure of the ...cast alloy consists of a dispersed eutectic ((Al) + Al
8
Cu
4
Er), Al
3
Er-phase inclusions located along the dendritic-cell boundaries, and a nonequilibrium AlCu phase. During annealing at 605°C before quenching, the intermetallic phases have high thermal stability: the particle size of Al
8
Cu
4
Er and Al
3
Er phases does not exceed 1–4 µm. The annealing of deformed sheets at temperatures below 300°C leads to a slight decrease in the hardness; grains elongated along the rolling direction are observed in the structure. With an increase in the annealing temperature from 350 to 550°C, the recrystallized grain size increases from 8 ± 1 to 14.5 ± 1.5 μm. The uniaxial tensile tests showed that the annealed alloy possesses sufficiently high strength characteristics: yield stress of 260–280 MPa, ultimate tensile strength of 291–312 MPa, and relative elongation of 5.5–6.1%.
It has been shown that the specific electrical resistance (SER) is an integral parameter of the physicochemical state of light-textured soils, especially of their solid phase properties. First ...relationships of SER with physical clay content, cation exchange capacity, and carbon content have been obtained and analyzed for light soils of the humid zone. It has been found that the relationships between the SER and the mentioned properties have exponential shapes y = aexp(-bx), where a and b are parameters; y is the SER value, Ωm; and x is the property value. The similar shapes of the equations allow for use of the SER for the assessment of the main cultivation and fertility elements of light soils in the humid zone (contents of physical clay and organic carbon and cation exchange capacity). On the basis of these relationships, a new approach has been proposed to the selection of SER values for drawing ISO-ohm lines delineating relatively homogeneous zones within the areas (fields) studied by electrophysical methods. Therefore, electrical surveys and ISO-ohm maps can find wide use in soil cover survey.
—The kinetics of ultraviolet induced transformation of polybutylmethacrylate has been described by using thermal decomposition mass-spectra. The enhancement of the neat polymer decomposition at low ...temperatures is observed in the spectra after low irradiation doses. Further growth of irradiation dose results in the decrease of the total amount of the monomer formed upon thermal decomposition. In the case of the polybutylmethacrylate–fullerene C
60
composite the changes of the spectra are observed in the same range of irradiation doses, however, the spectral shapes and intensities have different response to irradiation compared to neat polymer. The spectral changes are interpreted to be a consequence of binding between fullerene molecule and the products of decomposition of the side ester groups.
A comparative study is provided for the effect of Si and Fe impurities in relation to their concentration in the structure, phase composition, and mechanical properties of alloy ...Al–0.2Y–0.3Er–0.2Zr–0.05Sc. With a content of Fe and Si (in the amount of 0.15%), presence is noted of phases formed by iron and silicon impurities with an increased concentration of Zr, Er, and Y. These phases are not found in the structure of alloy with a lower concentration of Fe and Si (0.01%). Due to dilution of aluminum solid solution with Zr, Er and Y, alloy with an increased Fe and Si (0.15%) content shows a weaker hardening effect during annealing compared to alloy having a more supersaturated solid solution. Sc in both alloys is evenly distributed within the matrix of aluminum solid solution and does not form phases during crystallization. It is shown that the temperature for the start of recrystallization for these alloys is in the range 500–550 °C. The set of standard mechanical properties for sheet produced from these alloys is almost at the same level: yield strength of 155 MPa, ultimate strength of 166 MPa, elongation at 11.2% for alloy with 0.15% (Fe and Si) and 8.7% for alloy with 0.01% (Fe and Si). It is noted that after annealing (200 °C, 1 h) sheets hardness increases by 5
HV
, which may point to aluminum solid solution decomposition.
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