scholarly journals Perspective Material for Photoenergetics on the Basis of Silicon with Binary Elementary Cells

2018 ◽  
Vol 1 (1) ◽  
pp. 82
Author(s):  
M. K. Bakhadyrkhanov ◽  
U. X. Sodikov ◽  
Kh. M. Iliev ◽  
S. A. Tachilin ◽  
Tuerdi Wumaier
Keyword(s):  
Basic Material ◽  
Silicon Lattice ◽  
Fundamental Parameters ◽  
Impurity Atoms ◽  
Low Temperature Annealing ◽  
Diffusion Parameters ◽  
Composition And Structure ◽  
Semiconductor Compounds ◽  
Thermodynamic Conditions ◽  
Composition Structure

The paper proposes a scientifically-grounded, principally-new approach to managing the fundamental parameters of the basic material of electronic engineering as like silicon. The essence of the proposed approach is the formation of binary elementary cells in the silicon lattice involving elements III (B, Al, Ga, Zn) and V (P, As, Sb) groups in the form of Si2GaAs, Si2GaSb, etc. Taking electrical and chemical parameters of these impurity atoms into account, as well as their diffusion parameters in Si, the formation is determined by the most suitable pairs of atoms of groups III and V that allow obtaining silicon with the necessary composition and structure of binary elementary cells, as well as their more complex associations, up to the formation of nanocrystals of semiconductor connections AIIIBV. It is shown that by controlling the composition, structure and concentration of binary elementary cells, it is possible to significantly expand the spectral sensitivity of silicon, both in the IR and hλ > Eg directions. The formation of nanoclusters of AIIIBV semiconductor compounds in the silicon lattice significantly changes the emissivity of the material. It is established that the successive diffusion of elements of groups III and V in silicon and additional low-temperature annealing under certain thermodynamic conditions make it possible to ensure the maximum participation of the impurity atoms introduced in the formation of binary elementary cells. Silicon with binary elementary cells involving atoms of groups III and V is a new class of semiconductor material with unique functionality for modern optoelectronics and photoenergetics.

Multilayer Materials

MRS Bulletin ◽  
1990 ◽  
Vol 15 (2) ◽  
pp. 17-18 ◽  
Author(s):  
Troy W. Barbee
Keyword(s):  
Atomic Layer ◽  
Image Transmission ◽  
General Concept ◽  
Transmission Electron Micrograph ◽  
Electron Micrograph ◽  
Lattice Image ◽  
Structure Variation ◽  
Composition And Structure ◽  
Titanium Nickel ◽  
Composition Structure

Multilayers, as considered in the following articles, are manmade thin-film materials periodic in one dimension in composition or in composition and structure. This composition/structure variation is generated during synthesis, which is typically accomplished using atom-by-atom technologies. Individual component layers in a multilayer may vary in thickness from one atomic layer (~2 Å) to hundreds of atomic layers (~1,000 Å) of a given material.An example of these synthetic micro-structures, a lattice image transmission electron micrograph of a cross section of a hundred period titanium (63 Å)/titanium-nickel (40 Å) multilayer microstructure fabricated using magnetron sputtering, is shown on the cover of this issue of the MRS BULLETIN. The titanium-nickel layers are amorphous as a result of the low substrate temperature (<75°C) and the very large atomic quench rates characteristic of vapor deposition (>1012 K/s). The elemental titanium layers are fiber textured with the basal plane of this hexagonal close-pack structure element in the plane of the layers. These (00.1) planes are the ones lattice imaged in this electron micrograph.The general concept of a multilayer structure, as illustrated above, is now well accepted because the ability to synthesize such materials for scientific study and technological application has been demonstrated at many nationally and internationally based laboratories.

Microarray-Based Characterization of Microbial Community Functional Structure and Heterogeneity Associated with Acid Mine Drainages

2015 ◽  
Vol 1130 ◽  
pp. 40-44 ◽  
Author(s):  
Li Shen ◽  
Hua Qun Yin ◽  
Qi Hu ◽  
Xue Duan Liu ◽  
Guan Zhou Qiu
Keyword(s):  
Microbial Communities ◽  
Geographic Distribution ◽  
Mine Drainage ◽  
Diversity Indices ◽  
Aquatic Life ◽  
Acid Mine ◽  
Composition And Structure ◽  
Composition Structure ◽  
And Function

Acid mine drainage (AMD) presents numerous problems to the aquatic life and surrounding ecosystems. However, little is known about the geographic distribution, diversity, composition, structure and function of AMD microbial communities. In this study, an AMD-specific microarray was used to analyze nine AMD microbial communities, and showed that those nine AMD microbial communities had high variations measured by the number of detected genes, overlapping genes between samples, unique genes, and diversity indices. Statistical analyses indicated that the concentrations of Fe, S, Ca, Mg, Zn, Cu and pH had strong impacts on both phylogenetic and functional diversity, composition, and structure of AMD microbial communities. This study provides insights into our understanding of the geographic distribution, diversity, composition, structure and functional potential of AMD microbial communities and key environmental factors shaping them.

scholarly journals A model for producing polymer stabilizers of composites with a given macromolecule composition

2020 ◽  
Vol 82 (1) ◽  
pp. 262-266
Author(s):  
S. S. Glazkov ◽  
D. S. Glazkov ◽  
V. A. Kozlov ◽  
Y. F. Shutilin
Keyword(s):  
Mathematical Modeling ◽  
Least Squares Method ◽  
Reaction Medium ◽  
Background Information ◽  
Constant Composition ◽  
Reference Information ◽  
Composition And Structure ◽  
Composition Structure ◽  
The Given ◽  
Kinetics Of

An attempt has been made to obtain a working technological formula that regulates the addition of comonomer over time, which ensures the synthesis of a copolymer macromolecule with a constant composition and, accordingly, with predicted properties of both the copolymer and its modified porous composite materials. Mathematical modeling is based on the theory of the kinetics of copolymerization, which takes into account the reactivity of monomers by means of copolymerization constants of reacting comonomers. The starting base was the kinetics of the copolymerization of two comonomers, significantly differing in their reactivity, which required a sequential, stepwise supply of a less reactive monomer to the reaction medium with a more active monomer. This technological technique contributes to maintaining the constancy of the initial ratio of comonomers and, accordingly, the synthesis of a copolymer with a constant composition, structure and properties. The dependence of the sequence of supply of comonomer to the reaction medium required the introduction of a generalized effective binary copolymerization rate coefficient. To find the generalized coefficient of the copolymerization rate, the operation of logarithm was performed and the current expression of the dependence of the concentration change of the more active monomer in time in a linear form was translated. This mathematical technique made it possible to use software to process reference information to obtain the necessary coefficients for the working formula. As a result of mathematical modeling using the basic principles of binary copolymerization, the law of effective masses, and the least squares method, a working formula is obtained that allows one to regulate the given introduction of a less active monomer into the reaction medium in time. The model is analyzed using background information, the basic concepts of binary copolymerization and can be used in technological calculations when producing copolymers with specified characteristics in composition and structure.

scholarly journals FORMATION OF ZOOPLANKTON IN THE BOGUCHANY RESERVOIR DURING ITS FILLING

2021 ◽  
pp. 25-40
Author(s):  
N. Sheveleva
Keyword(s):  
Zooplankton Community ◽  
Water Area ◽  
Horizontal Distribution ◽  
First Year ◽  
Composition And Structure ◽  
Quantitative Development ◽  
Composition Structure ◽  
Quantitative Indicators ◽  
First Time ◽  
Artificial Reservoirs

For the first time, we present the materials of the spatial distribution of qualitative and quantitative indicators of zooplankton in the first year of top water level (TWL) in the Boguchany Reservoir. We indicate the dynamics of the formation of the zooplankton community in the Upper section of the reservoir during its filling (from 2013 to 2015). The Irkutsk, Bratsk, and Ust-Ilimsk reservoirs influence the composition and structure of zooplankton in the Boguchany Reservoir that closes the cascade of the Angara HPPs, and there is a great similarity of the crustacean and rotifer fauna with the upstream artificial reservoirs. During the study period (from 2013 to 2017), the plankton fauna included 84 species from 49 genera and 23 families. The horizontal distribution of quantitative indicators throughout the water area of the reservoir had a mosaic pattern. The relative and absolute proportion of rotifers in the composition of zooplankton decreased from the Upper section to the Lower one, and the dominance of crustaceans was opposite. Due to this, the maximum number (129±97.8 thou ind./m3) of zooplankton was recorded in the Upper section, and the biomass (2080±676 mg/m3) – in the Lower section. The obtained unique data on the composition, structure and quantitative development of zooplankton in the Boguchany Reservoir during its formation and filling are important for further monitoring of its state, including the assessment of the feeding of planktonophagous fish and juvenilefish.

scholarly journals Short-term effects of canopy and surface fire on centipede (Chilopoda) communities in a semi natural Mediterranean forest

2009 ◽  
Vol 20 (3) ◽  
Author(s):  
Emiliano Trucchi ◽  
Monica Pitzalis ◽  
Marzio Zapparoli ◽  
Marco Bologna
Keyword(s):  
Species Composition ◽  
Mediterranean Coast ◽  
Tree Canopy ◽  
Pitfall Trapping ◽  
Short Term ◽  
Surface Fire ◽  
Composition And Structure ◽  
Dominance Structure ◽  
Composition Structure ◽  
Species Composition And Structure

Species composition and structure of centipede (Chilopoda) communities were studied in a sub-urban burnt forest on the Mediterranean coast near Roma, Italy. The study was carried out in two sites affected by canopy fire (complete vegetation destruction), one affected by surface fire (persistence of tree canopy), and three unburnt sites. Monthly, quantitative/qualitative samplings were performed in each site from April 2001 to April 2002 by pitfall trapping and one hour active search. Analyses of species composition, dominance structure, diversity and colonization progress were performed. Centipede communities of the sites affected by canopy fire were simply structured, poor in both species richness and diversity; conversely, species composition, structure and diversity of the community affected by surface fire were scarcely modified.

Research of the composition, structure and properties of deposited alloys of the titanium—aluminum system doped with chrome

2021 ◽  
pp. 470-475
Author(s):  
A.I. Kovtunov ◽  
A.G. Bochkarev
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Heat Resistance ◽  
Titanium Aluminide ◽  
Titanium Aluminides ◽  
Structure And Properties ◽  
Composition And Structure ◽  
Titanium Aluminum ◽  
Composition Structure

The results of the study of the processes of argon-arc surfacing of alloys based on titanium aluminides doped with chromium are presented. The effect of surfacing modes on the chemical composition and structure of the deposited alloys has been established. The results of testing the hardness, wear resistance and heat resistance of chromium-alloyed alloys based on titanium aluminide are presented.

The Study of the Complex Mechanical Properties of Rolled Bars of VT6 Alloy as a Function of Chemical Composition and Structure Type

2020 ◽  
Vol 989 ◽  
pp. 283-289
Author(s):  
Yu.B. Egorova ◽  
L.V. Davydenko ◽  
I.M. Mamonov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Statistical Tests ◽  
Structure Type ◽  
Strength Properties ◽  
Alloying Elements ◽  
Mean Values ◽  
Composition And Structure ◽  
Composition Structure ◽  
The Stability

This paper presents the results of statistical tests, carried out to identify the mechanical properties of Ø 16-150 mm VT6 titanium alloy bars, as a function of their post-annealing chemical composition and structure. It is shown that the high variation of mechanical properties may be, due to fluctuations in the grade composition and structure type. 50% to 60% of variations in strength properties are due to composition + structure co-effects. To improve the stability of such properties, the paper identifies maximum permissible total fluctuations in the chemical composition in terms of aluminum/molybdenum equivalents of alloying elements and impurities. The research team has fitted the regression dependencies for evaluating the mean values of the mechanical properties of Ø 16-60 mm VT6 bars, as a function of the structure type and aluminum/molybdenum equivalents of the alloying elements and impurities.

scholarly journals Electrochemical deposition of tin-copper alloy coatings

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 49-57
Author(s):  
D. Y. Gulpa ◽  
I. I. Kuzmar ◽  
L. K. Kushner ◽  
N. V. Dezhkunov ◽  
A. A. Khmyl
Keyword(s):  
Copper Alloy ◽  
Base Alloy ◽  
Electrical Contacts ◽  
Limiting Current ◽  
Electronic Products ◽  
Composition And Structure ◽  
Long Time ◽  
Ultrasound Intensity ◽  
Cathode Current ◽  
Composition Structure

Solderable tin-base alloy coatings are widely used when assembling electronic products. The reorientation of production to lead-free technologies sets the task of developing new technological processes for the formation of coatings for electrical contacts with stable electrical properties, high soldering ability, which lasts for a long time. The features of the process of electrodeposition of coatings with a tin-copper alloy were experimentally investigated and the regularities of the influence of the electrolyte composition, current density, and ultrasound intensity on the cathode current efficiency of the alloy, the deposition rate, elemental composition, structure and functional properties of the precipitation were established. For sonochemical treatment an experimental setup developed at Research Laboratory 5.2 of BSUIR, which makes it possible to vary the intensity of ultrasonic vibrations in the range of 0.058– 1.7 W/cm2 , was used. It has been established that the use of ultrasound changes the formation mechanism of the electrochemical alloy, reduces cathodic polarization, increases the value of the limiting current and makes it possible to control the composition and structure of the precipitates. With an increase in the intensity from 0.12 to 0.95 W/cm2  the amount of copper in the coating increases by 4.5 times. The spreading coefficient of the solder is 92.59–98.44 %.

Doubly curved crystal (DCC) X-ray optics and applications

2002 ◽  
Vol 17 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Zewu Chen ◽  
Walter M. Gibson
Keyword(s):  
Thin Films ◽  
Low Power ◽  
X Rays ◽  
Enabling Technology ◽  
Ray Optics ◽  
X Ray ◽  
Composition And Structure ◽  
Composition Structure ◽  
Doubly Curved

Doubly curved crystal (DCC) X-ray optics provide an enabling technology for new portable, remote, and in situ applications of monochromatic X-rays for composition and structure analysis of amorphous, polycrystalline, and crystalline solids. Femtogram sensitivity for surface contamination, parts-per-billion (ppb) impurity levels for solids, and composition, structure and uniformity of thin films with compact, low power (20–50 W) source optic combinations are possible.

scholarly journals Dynamic Succession of Groundwater Functional Microbial Communities in Response to Emulsified Vegetable Oil Amendment during SustainedIn SituU(VI) Reduction

2015 ◽  
Vol 81 (12) ◽  
pp. 4164-4172 ◽  
Author(s):  
Ping Zhang ◽  
Wei-Min Wu ◽  
Joy D. Van Nostrand ◽  
Ye Deng ◽  
Zhili He ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Vegetable Oil ◽  
Relative Abundance ◽  
Pilot Scale ◽  
Functional Gene ◽  
Functional Genes ◽  
Composition And Structure ◽  
Composition Structure ◽  
And Function

ABSTRACTA pilot-scale field experiment demonstrated that a one-time amendment of emulsified vegetable oil (EVO) reduced groundwater U(VI) concentrations for 1 year in a fast-flowing aquifer. However, little is known about how EVO amendment stimulates the functional gene composition, structure, and dynamics of groundwater microbial communities toward prolonged U(VI) reduction. In this study, we hypothesized that EVO amendment would shift the functional gene composition and structure of groundwater microbial communities and stimulate key functional genes/groups involved in EVO biodegradation and reduction of electron acceptors in the aquifer. To test these hypotheses, groundwater microbial communities after EVO amendment were analyzed using a comprehensive functional gene microarray. Our results showed that EVO amendment stimulated sequential shifts in the functional composition and structure of groundwater microbial communities. Particularly, the relative abundance of key functional genes/groups involved in EVO biodegradation and the reduction of NO3−, Mn(IV), Fe(III), U(VI), and SO42−significantly increased, especially during the active U(VI) reduction period. The relative abundance for some of these key functional genes/groups remained elevated over 9 months. Montel tests suggested that the dynamics in the abundance, composition, and structure of these key functional genes/groups were significantly correlated with groundwater concentrations of acetate, NO3−, Mn(II), Fe(II), U(VI), and SO42−. Our results suggest that EVO amendment stimulated dynamic succession of key functional microbial communities. This study improves our understanding of the composition, structure, and function changes needed for groundwater microbial communities to sustain a long-term U(VI) reduction.

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