The stability of coordination polyhedrons and distribution of europium ions in Ca6BaP4O17

2020 ◽  
Vol 22 (38) ◽  
pp. 22096-22106
Author(s):  
Fengkai Ma ◽  
Rongfu Zhou ◽  
Fang Su ◽  
Yiyi Ou ◽  
Hongbin Liang
Keyword(s):  
Structural Transformation ◽  
Dynamic Environments ◽  
The Stability ◽  
Coordination Polyhedrons

Polyhedron-tilt-induced coordination structural transformation and the stabilities are intimately related to dynamic environments.

Theoretical studies on the structure and properties of DAT/BTNAT cocrystal under high pressure

2020 ◽  
Vol 98 (3) ◽  
pp. 128-133
Author(s):  
Liangyu Li ◽  
Weihua Zhu
Keyword(s):  
High Pressure ◽  
Structural Transformation ◽  
Density Functional ◽  
Hydrostatic Compression ◽  
Theoretical Studies ◽  
Dispersion Correction ◽  
Structure And Properties ◽  
Absorption Properties ◽  
Functional Theory ◽  
The Stability

The structural, electronic, and absorption properties of 3,5-diamino-1H-1,2,4-triazole (DAT) and 5,5′-bis(trinitromethyl)-3,3′-azo-1H-1,2,4-triazole (BTNAT) cocrystal under hydrostatic compression of 0–100 GPa were investigated by using periodic density functional theory with dispersion correction (DFT-D). The results indicate that a structural transformation occurred at 25 GPa. The structural transformation makes the positions of the molecules rearrange in the cocrystal and improves the stability and planarity. An analysis of the band gap and density of states indicates that the DAT/BTNAT cocrystal becomes more sensitive under compression. The absorption spectra illustrate that the DAT/BTNAT cocrystal has relatively high optical activity with the increasing pressure. Our work may offer some valuable information for understanding the behavior of energetic cocrystals under high pressure.

Chirality Induced by Structural Transformation in a Tensegrity: Theory and Experiment

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Li-Yuan Zhang ◽  
Zi-Long Zhao ◽  
Qing-Dong Zhang ◽  
Xi-Qiao Feng
Keyword(s):  
Structural Transformation ◽  
Structural Parameters ◽  
Tensile Force ◽  
Plane Deformation ◽  
Deformation Mode ◽  
Critical Value ◽  
Chiral Structure ◽  
Chiral Structures ◽  
The Stability ◽  
Theory And Experiment

Chiral structures have many technologically significant applications in engineering. In this paper, we investigate, both theoretically and experimentally, the structural transformation from a symmetric X-shaped tensegrity to a chiral structure under uniaxial tension. When the applied tensile force exceeds a critical value, the initially achiral structure would exhibit snap-through buckling. At the critical state, the in-plane deformation mode of the tensegrity switches into an off-plane one. The critical condition of the structural transformation is provided in terms of structural parameters. An experiment was performed to validate the theoretical model. This work may not only deepen our understanding of the stability of tensegrities but also help design chiral structures for engineering applications.

Structural Shifts in the Economy of the Russian Federation and Its Import Intensity in 2014–2019: Analysis of Macroeconomic Statistics.

2021 ◽  
Vol 28 (5) ◽  
pp. 5-27
Author(s):  
L. A. Strizhkova ◽  
L. I. Tishina ◽  
M. V. Selivanova
Keyword(s):  
Structural Transformation ◽  
Structural Changes ◽  
Methodological Approach ◽  
Value Added ◽  
International Investment ◽  
Macroeconomic Analysis ◽  
Russian Economy ◽  
The Stability ◽  
And Shifts ◽  
Import Intensity

The introductory part of the article formulates its objective – to characterize development conditions in Russia and main structural changes in the Russian economy (according to 2014–2019 data) from the standpoint of their compliance with the tasks of increasing the stability and quality of the country's economic growth during the transition of the world system to a new technological order. Аccording to the authors, this period is of particular interest in assessing and studying the experience associated with structural transformation in a highly unfavorable external condition amid tight monetary policy and restrictive income policy.The article sequentially addresses certain aspects of the structural transformation of the Russian economy. The authors, relying on macroeconomic statistics, assess shifts in production and use of products, investment, import intensity, the balance of payments, and international investment position, considering external and internal conditions.The paper focuses on analyzing the proportions of the economy according to the data of the Rosstat input-output tables (IOTs). The article provides estimates of structural changes in the dependence of the economy and its segments on types of imports, signifcant changes in the direction of the use of fnal products, including considering the dynamics of changes in the total input of intermediate imports. For the frst time, the characteristics of the concentration of gross value added (GVA) and gross domestic product (GDP) by areas of fnal demand are given. A methodological approach is proposed for monitoring shifts in import consumption by compiling annual summary tables with a minimum set of data obtained during the analytical processing of IOT information. Based on the results of testing this approach on data for 2016 and 2018, the authors rated cost product balances by the share of imports in the resources of products. Conclusions were drawn about the change in the import intensity of the economy for the selected types of products, the import intensity of Russian industries, and shifts in the distribution structure of types of imported products. The article formulates proposals for the development of measures necessary to consolidate and expand positive results of this stage in the development of the Russian economy and statistical support of macroeconomic analysis.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

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