scholarly journals FeSi2: a two-dimensional ferromagnet containing planar hexacoordinate Fe atoms

2022 ◽  
Author(s):  
Ying Zhao ◽  
Qinxi Liu ◽  
Jianpei Xing ◽  
Xue Jiang ◽  
Jijun Zhao

As an unconventional bonding pattern different from conventional chemistry, the concept of planar hypercoordinate atom was first proposed in the molecular system, and it has been recently extended to 2D...

2010 ◽  
Vol 19 (03) ◽  
pp. 427-436
Author(s):  
A. MENDOZA-GARCÍA ◽  
A. ROMERO-DEPABLOS ◽  
M. A. ORTEGA ◽  
J. L. PAZ ◽  
L. ECHEVARRÍA

We have developed an analytical method to describe the optical properties of nanoparticles, whose results are in agreement with the observed experimental behavior according to the size of the nanoparticle under analysis. Our considerations to describe plasmonic absorption and dispersion are based on the combination of the two-level molecular system and the two-dimensional quantum box models. Employing the optical stochastic Bloch equations, we have determined the system's coherence, from which we have calculated expressions for the absorption coefficient and refractive index. The innovation of this methodology is that it allows us to take into account the solvent environment, which induce quantum effects not considered by classical treatments.


1999 ◽  
Vol 55 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
Maryjane Tremayne ◽  
Elizabeth J. MacLean ◽  
Chiu C. Tang ◽  
Christopher Glidewell

The crystal structure of 2,4,6-triisopropylbenzenesulfonamide, C15H25NO2S, has been solved from X-ray powder diffraction data collected at 120 (1) K using synchrotron radiation and refined by Rietveld methods. The structure was solved by the application of a Monte Carlo method in which trial structures were generated by random movement of the molecule in the unit cell and assessed using a full-profile-fitting technique. Intramolecular flexibility was introduced into the structure solution in the form of four independent asymmetric rotors, allowing the isopropyl and sulfonamide groups to rotate freely within the molecule. The structure is monoclinic P21/c, a = 16.9600 (6), b = 8.1382 (2), c = 11.7810 (2) Å, β = 104.777 (2)° with Z = 4. The molecules are linked by N—H...O hydrogen bonds, with N...O distances of 2.77 (1) and 2.92 (1) Å, into two-dimensional sheets built from R^2_2(8) and R^6_6(20) rings.


1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.


2000 ◽  
Vol 179 ◽  
pp. 229-232
Author(s):  
Anita Joshi ◽  
Wahab Uddin

AbstractIn this paper we present complete two-dimensional measurements of the observed brightness of the 9th November 1990Hαflare, using a PDS microdensitometer scanner and image processing software MIDAS. The resulting isophotal contour maps, were used to describe morphological-cum-temporal behaviour of the flare and also the kernels of the flare. Correlation of theHαflare with SXR and MW radiations were also studied.


Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.


Author(s):  
B. Ralph ◽  
A.R. Jones

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.


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