scholarly journals NANOSTRUCTURES IN THE THIN LAYER OF COAL SUBSTANCE

2020 ◽  
pp. 746-757
Author(s):  
Виктор Михайлович Юров ◽  
Канат Мэтович Маханов ◽  
Василий Сергеевич Портнов
Keyword(s):  
Surface Layer ◽  
Thin Layer ◽  
Supramolecular Structure ◽  
Explosion Hazard ◽  
Physical Processes ◽  
Pure Metals ◽  
Bulk Structure ◽  
Structure Lead

В представленной работе рассмотрен поверхностный слой угольного вещества, структура и характеристики которого отличны от структуры объема. Этот слой имеет два уровня: d(I) равный 151,5 нм и d(II)≈10 ⋅ d равный 1515 нм для антрацита. Для чистых металлов d(I) равно 1 - 6 нм, что на 2 порядка меньше поверхностного слоя угольного вещества. Толщина этого слоя имеет порядок толщин высших фуллеренов С, равного 135 нм. Все эти особенности угольного вещества, имеющего углеродную основу и представляющего собой полимер с надмолекулярной структурой, приводят к тому, что именно поверхностный слой определяет физические процессы в нем, связанные с протеканием газов и жидкости, а также с явлениями взрывоопасности. In the present work, the surface layer of a coal substance is considered, the structure and characteristics of which are different from the bulk structure. This layer has two levels: d (I) equal to 151,5 nm and d(II) ≈ 10 ⋅ d equal to 1515 nm for anthracite. For pure metals d(I) is equal 1 - 6 nm, that is 2 orders of magnitude lesser than the surface layer of the coal substance. The thickness of this layer is of the order of 135 nm for the higher C fullerenes. All these features of a coal substance, which has a carbon base and is a polymer with a supramolecular structure, lead to the fact that it is the surface layer that determines the physical processes in it associated with the flow of gases and liquids, as well as with the phenomena of the explosion hazard.

scholarly journals Atomistic Simulations of Surface Relaxations in Ni, Al, and Their Ordered Alloys

1986 ◽  
Vol 82 ◽  
Author(s):  
S. P. Chen ◽  
A. F. Voter ◽  
D. J. Srolovitz
Keyword(s):  
Surface Layer ◽  
Atomistic Simulations ◽  
Atomic Diameter ◽  
Ordered Alloys ◽  
Pure Metals

ABSTRACTWe have performed a series of simulations to examine the atomistic nature of surface relaxations in pure metals and ordered alloys. The surface relaxations (∆dn, n+1) are shown to be oscillatory and to decay rapidly into the bulk. The period and form of the oscillation may be determined by simple geometrical arguments. The oscillation wavelength is always of the order of an atomic diameter. In pure metals, the surface layer of atoms always displaces inward. However, in the ordered alloys the larger atom may displace outward. On planes composed of more than one atom types, rippling occurs.

Investigation of Pulsed Laser Annealing of CdS Layers Designed for Thin-Layer Solar Cells

2010 ◽  
Vol 159 ◽  
pp. 109-112
Author(s):  
Peter Shindov ◽  
Roumen Kakanakov ◽  
Lidiya Bedikyan ◽  
Svetlana Kaneva ◽  
Teodora Anastasova
Keyword(s):  
Surface Layer ◽  
Solar Cells ◽  
Phase Composition ◽  
Thin Layer ◽  
Spray Pyrolysis ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Thin Layers ◽  
Electrical Measurements ◽  
Pulsed Laser Annealing

The effect of the pulsed – laser annealing on the parameters of CdS thin layers in the medium of oxygen was studied. The CdS thin layers were deposited by spray pyrolysis at different technological conditions. The changes of the layers’ characteristics were studied by SEM, XRD and XPS and electrical measurements were carried out. The results showed that a change in the morphology and the phase composition of the surface occurred; a by-surface layer consisted of CdО with high conductivity was formed in consequence of oxidation of CdS. The parameters of the CdS thin layers were retained in- depth after pulsed laser annealing. These results are discussed in the context of transparent layers in solar cells.

scholarly journals Upward nitrate transport by phytoplankton in oceanic waters: balancing nutrient budgets in oligotrophic seas

2014 ◽  
Author(s):  
Tracy A Villareal ◽  
Cynthia H. Pilskaln ◽  
Joseph P. Montoya ◽  
Mark Dennett
Keyword(s):  
Surface Layer ◽  
Pacific Ocean ◽  
Vertical Migration ◽  
Euphotic Zone ◽  
Optical Systems ◽  
Fundamental Aspect ◽  
Sufficient Evidence ◽  
Nitrate Transport ◽  
Physical Processes ◽  
Isotopic Tracers

In oceanic gyres, primary producers are numerically dominated by small (1-5 µm diameter) pro- and eukaryotic cells that primarily utilize recycled nutrients produced by rapid grazing turnover in a highly efficient microbial loop. Continuous losses of nitrogen to depth by sinking, either as single cells, aggregates or fecal pellets, are balanced by both nitrate inputs at the base of the euphotic zone and nitrogen-fixation. This input of N (new nitrogen) to balance export losses (the biological pump) is a fundamental aspect of nitrogen cycling and central to understanding carbon fluxes in the ocean. In the Pacific Ocean, detailed nitrogen budgets at the time-series station HOT require upward transport of nitrate from the nutricline (80-100 m) into the surface layer (~0-40 m) to balance productivity and export needs. However, concentration gradients are negligible and cannot support the fluxes. Physical processes can inject nitrate into the base of the euphotic zone, but the mechanisms for transporting this nitrate into the surface layer across many 10s of m in highly stratified systems are unknown. In these seas, vertical migration by the very largest 102-103 µm diameter) phytoplankton is common as a survival strategy to obtain nitrogen from sub-euphotic zone depths. This vertical migration is driven by buoyancy changes rather than by flagellated movement and can provide upward nitrogen transport as nitrate (mM concentrations) in the cells. However, the contribution of vertical migration to nitrate transport has been difficult to quantify over the required basin scales. In this study, we use towed optical systems and isotopic tracers to show that migrating diatom (Rhizosolenia) mats are widespread in the N. Pacific Ocean from 140°W to 175°E and together with other migrating phytoplankton (Ethmodiscus, Halosphaera, Pyrocystis, and solitary Rhizosolenia) can mediate time-averaged transport of N (235 µmol N m-2 d-1) equivalent to eddy nitrate injections (242 µmol NO3- m-2 d-1). This upward biotic transport can close nitrate budgets in the upper 250 m of the central Pacific Ocean and together with diazotrophy creates a surface zone where biological nutrient inputs rather than physical processes dominate the new N flux. In addition to these numerically rare large migrators, there is extensive evidence in the literature of ascending behavior in small phytoplankton that contributes to upward flux as well. Although passive downward movement has dominated models of phytoplankton flux, there is now sufficient evidence to require a rethinking of this paradigm. Quantifying these fluxes is a challenge for the future and requires a reexamination of individual phytoplankton sinking rates as well as methods for capturing and enumerating ascending phytoplankton in the sea.

Simulation of neutron-physical processes in the surface layer of a fuel kernel

Atomic Energy ◽  
2008 ◽  
Vol 104 (6) ◽  
pp. 463-469 ◽  
Author(s):  
A. N. Andrianov ◽  
V. G. Baranov ◽  
G. V. Tikhomirov ◽  
A. V. Khlunov
Keyword(s):  
Surface Layer ◽  
Physical Processes ◽  
Fuel Kernel

scholarly journals Coupling and decoupling processes in monsoonal surface layer using MONTBLEX-90 tower data

MAUSAM ◽  
2021 ◽  
Vol 48 (3) ◽  
pp. 375-384
Author(s):  
T.N. JHA ◽  
K. C. SINHA RAY ◽  
H. N. SRIVASTAVA
Keyword(s):  
Surface Layer ◽  
Eddy Viscosity ◽  
Surface Soil ◽  
Turbulent Transfer ◽  
Bulk Richardson Number ◽  
Physical Processes ◽  
Stable Case ◽  
Class A ◽  
Order Of Magnitude ◽  
Surface Soil Temperature

ABSTRACT. MONI'BLEX-90 data of Varanasi and Jodhpur have been used to study the physical processes in the surface layer. The results show that turbulent transfer of heat, momentum and moisture commence at an average eddy viscosity of an order of magnitude 5.13 × 10-1 J -s kg-1 during rainy day. In absolutely stable case, eddy viscosity may be equal to 4.94 × 10-4 J-s kg-1 or less to decouple surface layer from rest of the planetary boundary layer for extinction of the turbulent transfer of fluxes. These results were based on 8m and 15m meteorological tower observations and surface soil temperature using analytical solution of Byun (1990) and K theory. It was found that the surface layer is decoupled only in case of stability of Class - A because bulk Richardson number is greater than zero and corresponding stability parameter is positive.    

scholarly journals Визуализация проводящих каналов в полимерных слоях методом атомно-силовой микроскопии с проводящим зондом

2021 ◽  
Vol 91 (10) ◽  
pp. 1560
Author(s):  
В.М. Корнилов ◽  
А.Н. Лачинов ◽  
А.Р. Юсупов
Keyword(s):  
Experimental Study ◽  
Atomic Force Microscopy ◽  
Surface Layer ◽  
Supramolecular Structure ◽  
Current Flow ◽  
Electrophysical Properties ◽  
Current Image ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ultrathin Polymer Films

The results of an experimental study of the local electrophysical properties of ultrathin polymer films by atomic force microscopy with a conducting probe are presented. It is established that visualization of current flow sites (conducting channels) is possible in areas from which the surface layer has been mechanically removed. The conducting channels in the current image have the form of individual points with a height corresponding to the locally flowing current. It is found that the location of the observed channels correlates well with the model of conductivity along the grain boundaries of the supramolecular structure of the polymer.

scholarly journals Increasing the wear and corrosion resistance of steel parts by methods of complex boronikeling and borovolframing

2021 ◽  
pp. 50-54
Author(s):  
Б.Д. Лыгденов ◽  
М.А. Гурьев ◽  
С.Г. Иванов ◽  
Ц. Чжэн ◽  
А.М. Гурьев
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Thermal Treatment ◽  
Boron Carbide ◽  
Structure And Properties ◽  
Multiphase Structure ◽  
Wear And Corrosion ◽  
Pure Metals ◽  
Wear And Corrosion Resistance ◽  
And Tungsten

The paper presents ways to increase the wear and corrosion resistance of steel parts by chemical and thermal treatment methods. Comprehensive studies of the structure and properties of St3 steel samples were carried out after simultaneous complex saturation with boron and nickel, boron and tungsten from saturating coatings based on boron carbide. Both compounds of these elements (oxides, carbides, borides) and pure metals were used as suppliers of nickel and tungsten. Studies have shown that multicomponent saturation processes make it possible to form a multiphase structure of a surface layer with a complex of useful properties. Moreover, by chemical-thermal treatment it is possible to obtain such a combination of properties of the hardened product, which cannot be obtained by other methods.

scholarly journals Electric-field-driven octahedral rotation in perovskite

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wonshik Kyung ◽  
Choong H. Kim ◽  
Yeong Kwan Kim ◽  
Beomyoung Kim ◽  
Chul Kim ◽  
...  
Keyword(s):  
Surface Layer ◽  
Electric Field ◽  
Physical Properties ◽  
Condensed Matter ◽  
Perovskite Oxides ◽  
Perovskite Materials ◽  
In Situ Control ◽  
Surface Electric Field ◽  
Bulk Structure

AbstractRotation of MO6 (M = transition metal) octahedra is a key determinant of the physical properties of perovskite materials. Therefore, tuning physical properties, one of the most important goals in condensed matter research, may be accomplished by controlling octahedral rotation (OR). In this study, it is demonstrated that OR can be driven by an electric field in Sr2RuO4. Rotated octahedra in the surface layer of Sr2RuO4 are restored to the unrotated bulk structure upon dosing the surface with K. Theoretical investigation shows that OR in Sr2RuO4 originates from the surface electric field, which can be tuned via the screening effect of the overlaid K layer. This work establishes not only that variation in the OR angle can be induced by an electric field, but also provides a way to control OR, which is an important step toward in situ control of the physical properties of perovskite oxides.

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