Aspen
Populus tremula
L. (Salicaceae) is the fast-growing tree species of environmental and economic value. Aspen is capable of reproduction by both seeds and vegetative means, forming root sprouts. ...In an adult stand, identification of ramets of one clone among the trees of seed origin based on their morphology is difficult. A panel of 14 microsatellite loci developed for individual identification of aspen was applied for the clonal structure analysis in four natural aspen stands of the European part of Russia: Moscow and Voronezh oblasts, the Mari-El Republic, and the Republic of Tatarstan. In 52 trees from the Moscow sample, 41 multilocus genotypes were identified; in the Voronezh sample, among 30 individuals, 25 different genotypes were detected; and in the sample from Mari-El, 32 trees were represented by 13 genotypes. In the stand from Sabinsky Forestry, Tatarstan, all of the examined 29 trees were represented by a single genotype. The ancestral tree carrier of this genotype which was the most heterozygous (0.929) among all studied aspen individuals (sample mean, 0.598) obviously has spread over a large territory during several cutting and reproduction cycles, currently occupying the area of 2.2 ha. For aspen, usually suffering from Aspen trunk rot, such high viability is evidence of resistance to the main pathogens. The revealed superclone deserves further study with karyological methods and flow cytometry to determine ploidy level and analysis of the growth rate and the quality of wood for possible use in plantation forest production.
Abrasive finishing of flat parts Sirotenko, L. D.; Khanov, A. M.; Muratov, K. R.
Russian engineering research,
10/2015, Letnik:
35, Številka:
10
Journal Article
Recenzirano
The abrasive finishing of flat parts is investigated, to establish the influence of the technological parameters on the machining forces. A mathematical model is proposed for use in the regulation of ...plane finishing so as to ensure high quality of the machined surface.
Structure formation in the surface layer of steel 20 during the laser welding of steel H13 (analog #4Kh5MF1S#), which was performed using a LENS 850-R installation with a laser having power of 1 kW ...by several standard schemes, is investigated. The influence of welding technology on the formation of a nonuniform structure and hardness by the welding layers is investigated. Metallographic, spectral, and X-ray structural analyses are performed. A considerable variation in the chemical composition of layers compared with the chemical composition of the initial steel H13 is shown. Welding heating at 650 and 750°C leads to the structure leveling and the hardness lowering. The factors affecting the complex character of structure formation and, correspondingly, variations in microhardness for all types of welding are revealed.
The proton yields at an angle of 3.5° have been measured in the FRAGM experiment on the fragmentation of carbon ions with the energies
T
0
= 0.6, 0.95, and 2.0 GeV/nucleon on a beryllium target at ...the heavy-ion accelerator complex TWAC (terawatt accumulator, Institute for Theoretical and Experimental Physics). The data are represented in the form of the dependences of the invariant cross section for proton yield on the cumulative variable
x
in the range of 0.9 <
x
< 2.4. This invariant cross section varies within six orders of magnitude. The proton spectra have been analyzed within the theoretical approach of the fragmentation of quark clusters with the fragmentation functions obtained in the quark-gluon string model. The probabilities of the existence of six- and nine-quark clusters in the carbon nuclei are estimated as 8–12 and 0.2–0.6%, respectively. The results are compared to the estimated of quark effects obtained by other methods.
The internal abrasive machining of thermoprotective rubber coatings with constant retaining force on the grinding wheel is studied, theoretically and experimentally. A model of rubber failure in ...abrasive machining is proposed on the basis of the work of a single abrasive grain in contact with the machined surface. A relation is established between the components of the grinding force and the normal and tangential contact stresses at the working surfaces of a single grain of the wheel.
The D0 Silicon Microstrip Tracker Ahmed, S.N.; Aoki, M.; Åsman, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
634, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This paper describes the mechanical design, the readout chain, the production, testing and the installation of the Silicon Microstrip Tracker of the D0 experiment at the Fermilab Tevatron collider. ...In addition, we describe the performance and operational experience of the detector during the experiment data collection between 2001 and 2010.
The purpose of the study is to obtain the missing information related to the assessment of the degree of influence of changes in some socio-economic factors on the state of crime and its individual ...manifestations. The motivation for the study is related to the initiative of the President of the Republic of Kazakhstan Kassym Jomart Tokayev to increase the minimum wage. The justification for the increase in the minimum wage was a calculation that showed an increase in gross domestic product by 1.5%. The method of research is computer modeling based on the functioning of a neural network. The creation and training of the neural network was based on official statistical data of the Republic of Kazakhstan. At the initial stage of the study, the effectiveness of the chosen method was tested in comparison with other methods of information processing and analysis. The test showed a higher accuracy of calculation using a computer neural network. The dependence of changes in the minimum wage with an increase in gross domestic product and a decrease in the crime rate was confirmed. At the next, main stage of the study, there was a need to improve the neural network by optimizing the input matrix intended for training. Optimization lies in the fact that the learning matrix was formed by those values of socio-economic parameters, the impact of which on the level of crime and crime associated with manifestations of terrorism and extremism is maximal. Test comparisons of calculation results using neural network training optimization showed more accurate data compared to standard neural network training. Using a more advanced neural network, modeling of the expanded impact of changes in the minimum wage on the level of crime and criminal activity of an extremist and terrorist nature was carried out. The simulation results showed that the dependence of changes in the crime rate on changes in the minimum wage has a more complex nature of influence, in which it is important to determine its optimal value. The increase in the minimum wage has practically no effect on crimes of special gravity. They can mitigate the manifestations of peak activity of crimes of particular severity, but they do not have a significant impact on this type of crime. The research group notes the universality of the described software tools. Its application can be significantly expanded and used in various applications related to law enforcement. The authors declare no conflicts of interests.
PDF
