533 research outputs found
Distribution of periphytic diatoms in the rivers of the Lake Ladoga basin (Northwestern Russia).
Relationships between distribution of periphytic diatoms and environmental variables in 19 rivers of the Lake Ladoga basin (Northwestern Russia) were examined using gradient
analysis. On the basis of geology and river water chemistry, the Lake Ladoga basin could be separated into twomain parts, the northern and the southern sub-basin. The rivers in the northern sub-basin are slightly acidic and low in conductivity (mean value 53 mS cmβ1); the rivers in the southern sub-basin have neutral to slightly alkaline waters with higher conductivities (mean value 168 mS cmβ1). A detrended correspondence analysis (DCA)defined two groups of rivers generally corresponding to the two main parts of the Lake Ladoga basin. Fragilaria capucina var. rumpens, Frustulia saxonica and Tabellaria flocculosa were the typical species for the northern sub-basin, whereas Cocconeis placentula var. euglypta, Ulnaria ulna and Gomphonema parvulum were characteristic species
for the southern sub-basin. A canonical correspondence analysis (CCA) identified conductivity, pH, bicarbonate, total phosphorus and water colour as the most important
environmental variables related to changes in assemblage structure. Both DCA and CCA ordination showed that conductivity related to geology was the most important variable,while concentration of total phosphorus was the second most important variable.Weighted averaging was used to infer total phosphorus from relative biomass of diatoms. The predictive ability of the inference model was sufficiently strong with r2 = 0.71 and RMSEP =
1.9 mg Lβ1. These results strongly support the use of a diatom-based inference phosphorus model for indicating eutrophication in the rivers of the Lake Ladoga basin
Elastic deformation due to tangential capillary forces \ud
A sessile liquid drop can deform the substrate on which it rests if the solid is sufficiently βsoft.β In this paper we compute the detailed spatial structure of the capillary forces exerted by the drop on the solid substrate using a model based on Density Functional Theory. We show that, in addition to the normal forces, the drop exerts a previously unaccounted tangential force. The resultant effect on the solid is a pulling force near the contact line directed towards the interior of the drop, i.e., not along the interface. The resulting elastic deformations of the solid are worked out and illustrate the importance of the tangential force
Contact angles on a soft solid: from Young's law to Neumann's law
The contact angle that a liquid drop makes on a soft substrate does not obey
the classical Young's relation, since the solid is deformed elastically by the
action of the capillary forces. The finite elasticity of the solid also renders
the contact angles different from that predicted by Neumann's law, which
applies when the drop is floating on another liquid. Here we derive an
elasto-capillary model for contact angles on a soft solid, by coupling a
mean-field model for the molecular interactions to elasticity. We demonstrate
that the limit of vanishing elastic modulus yields Neumann's law or a slight
variation thereof, depending on the force transmission in the solid surface
layer. The change in contact angle from the rigid limit (Young) to the soft
limit (Neumann) appears when the length scale defined by the ratio of surface
tension to elastic modulus reaches a few molecular sizes
Sharp change over from compound nuclear fission to shape dependent quasi fission
Fission fragment mass distribution has been measured from the decay of
Bk nucleus populating via two entrance channels with slight difference
in mass asymmetries but belonging on either side of the Businaro Gallone mass
asymmetry parameter. Both the target nuclei were deformed. Near the Coulomb
barrier, at similar excitation energies the width of the fission fragment mass
distribution was found to be drastically different for the N +
Th reaction compared to the B + U reaction. The entrance
channel mass asymmetry was found to affect the fusion process sharply.Comment: 4 pages,6 figure
Π‘ΠΎΠ³Π»Π°ΡΠΎΠ²Π°Π½ΠΈΠ΅ ΡΡΠ³ΠΎΠ²ΠΎ-ΡΡΠ΅ΠΏΠ½ΡΡ ΠΊΠ°ΡΠ΅ΡΡΠ² Π΄Π²ΠΈΠΆΠΈΡΠ΅Π»Π΅ΠΉ ΡΠ΅Π»ΡΡΠΊΠΎΡ ΠΎΠ·ΡΠΉΡΡΠ²Π΅Π½Π½ΡΡ ΠΌΠΎΠ±ΠΈΠ»ΡΠ½ΡΡ ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ ΡΡΠ΅Π΄ΡΡΠ² Ρ Π΄ΠΎΠΏΡΡΡΠΈΠΌΡΠΌ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΡΠΌ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ΠΌ Π½Π° ΠΏΠΎΡΠ²Ρ
Modern highly mechanized agricultural production is characterized by the incompatibility of simultaneous matching of the maximum pressure of agricultural mobile equipment movers on the soil and the possibility of increasing the tractors energy saturation when equipping them with existing wheel engines.(Research purpose) To coordinate the maximum pressure on the soil with the permissible norms, weight utilization factors and the level of tractors energy saturation.(Materials and methods) The authors used a calculated method for determining the maximum pressure on the soil using a universal tire characteristic.(Results and discussion) The authors found that when performing spring works on closing moisture and sowing row crops at a maximum pressure of 80 kilopascals, corresponding to all types of soil, the most mass universal row tractor Belarus 1020 had a maximum pressure of 150 kilopascals, which was 70 kilopascals higher than the permissible one for the corresponding crop shortage. They found that replacing ordinary tires with agrophilic tires could increase the area of the contact spot by 16 percent, while reducing the coefficient of unevenness and increasing the coefficient of use of the adhesion weight. The main condition for replacing ordinary tires with agrophilic tires was to keep the traction force unchanged.(Conclusions) Summarizing the results of the research as agrophilic direction, ensuring the compliance impacts on soil and positively solving the problems of saturation, it is possible to recommend the development of navigation systems in achieving utilization hitch weight equal to 0.5 (low tire pressure), equal to 0.6 (rubber joint with torsion bar suspension) and 0.7 (rubber track). It was found that the conducted research, taking into account the available data on traction tests of the T-250 tractor, would allow to include an agrophilic concept with a hypothetical dependence of the adhesion weight use factor on the longitudinal unevenness coefficient in the revised State Standard 27021-86 βAgricultural and forestry Tractors. Traction classesβ.Π‘ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠ΅ Π²ΡΡΠΎΠΊΠΎΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ΅ ΡΠ΅Π»ΡΡΠΊΠΎΡ
ΠΎΠ·ΡΠΉΡΡΠ²Π΅Π½Π½ΠΎΠ΅ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²ΠΎ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΠ΅ΡΡΡ Π½Π΅ΡΠΎΠ²ΠΌΠ΅ΡΡΠΈΠΌΠΎΡΡΡΡ ΠΎΠ΄Π½ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΡΠ΅Π±ΠΎΠ²Π°Π½ΠΈΠΉ ΡΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΉ ΠΊ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΌΡ Π΄Π°Π²Π»Π΅Π½ΠΈΡ Π΄Π²ΠΈΠΆΠΈΡΠ΅Π»Π΅ΠΉ ΡΠ΅Π»ΡΡΠΊΠΎΡ
ΠΎΠ·ΡΠΉΡΡΠ²Π΅Π½Π½ΠΎΠΉ ΠΌΠΎΠ±ΠΈΠ»ΡΠ½ΠΎΠΉ ΡΠ΅Ρ
Π½ΠΈΠΊΠΈ Π½Π° ΠΏΠΎΡΠ²Ρ ΠΈ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠ΅ΠΉ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ ΡΠ½Π΅ΡΠ³ΠΎΠ½Π°ΡΡΡΠ΅Π½Π½ΠΎΡΡΠΈ ΡΡΠ°ΠΊΡΠΎΡΠΎΠ² ΠΏΡΠΈ ΠΎΡΠ½Π°ΡΠ΅Π½ΠΈΠΈ ΠΈΡ
ΡΡΡΠ΅ΡΡΠ²ΡΡΡΠΈΠΌΠΈ ΠΊΠΎΠ»Π΅ΡΠ½ΡΠΌΠΈ Π΄Π²ΠΈΠΆΠΈΡΠ΅Π»ΡΠΌΠΈ.(Π¦Π΅Π»Ρ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ) Π‘ΠΎΠ³Π»Π°ΡΠΎΠ²Π°ΡΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ΅ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ Π½Π° ΠΏΠΎΡΠ²Ρ Ρ Π΄ΠΎΠΏΡΡΡΠΈΠΌΡΠΌΠΈ Π½ΠΎΡΠΌΠ°ΠΌΠΈ, ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ°ΠΌΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠ΅ΠΏΠ½ΠΎΠ³ΠΎ Π²Π΅ΡΠ° ΠΈ ΡΡΠΎΠ²Π½Π΅ΠΌ ΡΠ½Π΅ΡΠ³ΠΎΠ½Π°ΡΡΡΠ΅Π½Π½ΠΎΡΡΠΈ ΡΡΠ°ΠΊΡΠΎΡΠΎΠ².(ΠΠ°ΡΠ΅ΡΠΈΠ°Π»Ρ ΠΈ ΠΌΠ΅ΡΠΎΠ΄Ρ) ΠΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π»ΠΈ ΡΠ°ΡΡΠ΅ΡΠ½ΡΠΉ ΠΌΠ΅ΡΠΎΠ΄ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ Π΄Π°Π²Π»Π΅Π½ΠΈΡ Π½Π° ΠΏΠΎΡΠ²Ρ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΡΠ½ΠΈΠ²Π΅ΡΡΠ°Π»ΡΠ½ΠΎΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΡΠΈΠ½Ρ.(Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈ ΠΎΠ±ΡΡΠΆΠ΄Π΅Π½ΠΈΠ΅) Π£ΡΡΠ°Π½ΠΎΠ²ΠΈΠ»ΠΈ, ΡΡΠΎ ΠΏΡΠΈ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΠΈ Π²Π΅ΡΠ΅Π½Π½ΠΈΡ
ΡΠ°Π±ΠΎΡ ΠΏΠΎ Π·Π°ΠΊΡΡΡΠΈΡ Π²Π»Π°Π³ΠΈ ΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΠΏΠΎΡΠ΅Π²Π° ΠΏΡΠΎΠΏΠ°ΡΠ½ΡΡ
ΠΊΡΠ»ΡΡΡΡ ΠΏΡΠΈ Π΄ΠΎΠΏΡΡΡΠΈΠΌΠΎΠΌ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΌ Π΄Π°Π²Π»Π΅Π½ΠΈΠΈ 80 ΠΊΠΈΠ»ΠΎΠΏΠ°ΡΠΊΠ°Π»Π΅ΠΉ, ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠ΅ΠΌ Π²ΡΠ΅ΠΌ ΡΠΈΠΏΠ°ΠΌ ΠΏΠΎΡΠ², ΡΠ°ΠΌΡΠΉ ΠΌΠ°ΡΡΠΎΠ²ΡΠΉ ΡΠ½ΠΈΠ²Π΅ΡΡΠ°Π»ΡΠ½ΠΎ-ΠΏΡΠΎΠΏΠ°ΡΠ½ΠΎΠΉ ΡΡΠ°ΠΊΡΠΎΡ ΠΠ΅Π»Π°ΡΡΡ 1020 ΠΈΠΌΠ΅Π΅Ρ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ΅ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ 150 ΠΊΠΈΠ»ΠΎΠΏΠ°ΡΠΊΠ°Π»Π΅ΠΉ, ΡΡΠΎ Π½Π° 70 ΠΊΠΈΠ»ΠΎΠΏΠ°ΡΠΊΠ°Π»Π΅ΠΉ ΠΏΡΠ΅Π²ΡΡΠ°Π΅Ρ Π΄ΠΎΠΏΡΡΡΠΈΠΌΠΎΠ΅ ΠΏΡΠΈ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠ΅ΠΌ Π½Π΅Π΄ΠΎΠ±ΠΎΡΠ΅ ΡΡΠΎΠΆΠ°Ρ. Π£ΡΡΠ°Π½ΠΎΠ²ΠΈΠ»ΠΈ, ΡΡΠΎ Π·Π°ΠΌΠ΅Π½Π° ΠΎΡΠ΄ΠΈΠ½Π°ΡΠ½ΡΡ
ΡΠΈΠ½ Π½Π° Π°Π³ΡΠΎΡΠΈΠ»ΡΠ½ΡΠ΅ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΡΠ²Π΅Π»ΠΈΡΠΈΡΡ ΠΏΠ»ΠΎΡΠ°Π΄Ρ ΠΏΡΡΠ½Π° ΠΊΠΎΠ½ΡΠ°ΠΊΡΠ° Π½Π° 16 ΠΏΡΠΎΡΠ΅Π½ΡΠΎΠ² Ρ ΠΎΠ΄Π½ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΠΌ ΡΠΌΠ΅Π½ΡΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° Π½Π΅ΡΠ°Π²Π½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ ΠΈ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠ΅ΠΏΠ½ΠΎΠ³ΠΎ Π²Π΅ΡΠ°. ΠΡΠΈΠ½ΡΠΈΠΏΠΈΠ°Π»ΡΠ½ΡΠΌ ΡΡΠ»ΠΎΠ²ΠΈΠ΅ΠΌ Π·Π°ΠΌΠ΅Π½Ρ ΠΎΡΠ΄ΠΈΠ½Π°ΡΠ½ΡΡ
ΡΠΈΠ½ Π½Π° Π°Π³ΡΠΎΡΠΈΠ»ΡΠ½ΡΠ΅ ΡΠ»ΡΠΆΠΈΡ ΡΠΎΡ
ΡΠ°Π½Π΅Π½ΠΈΠ΅ Π½Π΅ΠΈΠ·ΠΌΠ΅Π½Π½ΡΠΌ ΡΠΎΠ·Π΄Π°Π²Π°Π΅ΠΌΠΎΠ³ΠΎ ΡΡΠ°ΠΊΡΠΎΡΠΎΠΌ ΡΡΠ³ΠΎΠ²ΠΎΠ³ΠΎ ΡΡΠΈΠ»ΠΈΡ.(ΠΡΠ²ΠΎΠ΄Ρ) ΠΠΏΡΠ΅Π΄Π΅Π»ΠΈΠ»ΠΈ ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΡΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΡ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠ΅ΠΏΠ½ΠΎΠ³ΠΎ Π²Π΅ΡΠ°: Π΄Π»Ρ ΡΠΈΠ½ ΡΠ²Π΅ΡΡ
Π½ΠΈΠ·ΠΊΠΎΠ³ΠΎ Π΄Π°Π²Π»Π΅Π½ΠΈΡ β 0,5, Π΄Π»Ρ ΡΠ΅Π·ΠΈΠ½ΠΎΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ°ΡΠ½ΠΈΠΈΡΠ° Ρ ΡΠΎΡΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΠΎΠ΄Π²Π΅ΡΠΊΠΎΠΉ -- 0,6, Π΄Π»Ρ ΡΠ΅Π·ΠΈΠ½ΠΎΠ°ΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ Π³ΡΡΠ΅Π½ΠΈΡΡ β 0,7. Π£ΡΡΠ°Π½ΠΎΠ²ΠΈΠ»ΠΈ, ΡΡΠΎ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½Π½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Ρ ΡΡΠ΅ΡΠΎΠΌ ΠΈΠΌΠ΅ΡΡΠΈΡ
ΡΡ Π΄Π°Π½Π½ΡΡ
ΠΎ ΡΡΠ³ΠΎΠ²ΡΡ
ΠΈΡΠΏΡΡΠ°Π½ΠΈΡΡ
Π³ΡΡΠ΅Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΡΡΠ°ΠΊΡΠΎΡΠ° Π’-250, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡ Π²ΠΊΠ»ΡΡΠΈΡΡ Π°Π³ΡΠΎΡΠΈΠ»ΡΠ½ΡΡ ΠΊΠΎΠ½ΡΠ΅ΠΏΡΠΈΡ Ρ Π³ΠΈΠΏΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ (ΠΏΡΠ΅Π΄ΠΏΠΎΠ»Π°Π³Π°Π΅ΠΌΠΎΠΉ) Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡΡ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠ΅ΠΏΠ½ΠΎΠ³ΠΎ Π²Π΅ΡΠ° ΠΎΡ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΏΡΠΎΠ΄ΠΎΠ»ΡΠ½ΠΎΠΉ Π½Π΅ΡΠ°Π²Π½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ Π² ΠΏΠ΅ΡΠ΅ΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅ΠΌΡΠΉ ΠΠΠ‘Π’ 27021-86 Β«Π’ΡΠ°ΠΊΡΠΎΡΡ ΡΠ΅Π»ΡΡΠΊΠΎΡ
ΠΎΠ·ΡΠΉΡΡΠ²Π΅Π½Π½ΡΠ΅ ΠΈ Π»Π΅ΡΠΎΡ
ΠΎΠ·ΡΠΉΡΡΠ²Π΅Π½Π½ΡΠ΅. Π’ΡΠ³ΠΎΠ²ΡΠ΅ ΠΊΠ»Π°ΡΡΡΒ»
Experimental evidence for the separability of compound-nucleus and fragment properties in fission
The large body of experimental data on nuclear fission is analyzed with a
semi-empirical ordering scheme based on the macro-microscopic approach and the
separability of compound-nucleus and fragment properties on the fission path.
We apply the statistical model to the non-equilibrium descent from saddle to
scission, taking the influence of dynamics into account by an early freeze out.
The present approach reveals a large portion of common features behind the
variety of the complex observations made for the different systems. General
implications for out-of-equilibrium processes are mentioned.Comment: 11 pages, 3 figure
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