Identification and characterization of a novel Mn–N nitride formed in Fe–Mn–N alloy

2003 ◽  
Vol 36 (1) ◽  
pp. 103-108 ◽  
Author(s):  
M. Gouné ◽  
A. Redjaïmia ◽  
T. Belmonte ◽  
H. Michel
Keyword(s):  
Crystal Structure ◽  
Theory Analysis ◽  
Ferritic Matrix ◽  
Tetragonal System ◽  
Phase Crystal ◽  
20 Nm ◽  
New Phase ◽  
Identification And Characterization ◽  
Electron Microdiffraction

An unexpected phase, formed throughout the ferritic matrix of an Fe–Mn (1.62 wt% Mn) alloy during a nitriding treatment at 843 K for 8 h, is analysed. This new phase, labelled θ′, is a metastable Mn nitride. It adopts the form of plates, with length 200 nm and width 20 nm. Its crystal structure is established by electron microdiffraction in conjunction with group-theory analysis. This nitride crystallizes in the tetragonal system and belongs to the space groupP 42/m 2/m 2/cwith the following lattice parameters: a_{\theta'} = 2.876 Å and c_{\theta'} = 5.752 Å. The θ′-phase crystal lattice is oriented with respect to the surrounding ferritic matrix according to the cube-on-cube orientation relationship, namely: (100)_{\theta'} || (200)_\alpha, (010)_{\theta'} || (020)_\alpha and (002)_{\theta'} || (002)_\alpha.

scholarly journals The preparation and characterization of SeCl3SbF6, improved syntheses of MCl3(As/Sb)F6 (M = S, Se), and the X-ray crystal structure determination of SeCl3AsF6 and a new phase of SBr3SbF6

1996 ◽  
Vol 74 (9) ◽  
pp. 1671-1681 ◽  
Author(s):  
Jack Passmore ◽  
Paul D. Boyle ◽  
Gabriele Schatte ◽  
Todd Way ◽  
T. Stanley Cameron
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Ft Raman Spectroscopy ◽  
New Phase ◽  
Ft Raman

Alternative and, in some cases, improved syntheses of the salts MX3(As/Sb)F6 (M = S, Se) and SCl3(SbCl6/AlCl4) are described. In addition, the synthesis of SeCl3SbF6 is reported. The compounds were characterized by FT–Raman spectroscopy and the X-ray crystal structures of SeCl3AsF6 (also 77Se NMR) and a new phase of SBr3SbF6 were determined. Crystals of SeCl3AsF6 and SBr3SbF6 are monoclinic, space group P21/c with [values for SBr3SbF6 in brackets] a = 7.678(1) [8.137(1)] Å, b = 9.380(3) [9.583(2)] Å, c = 11.920(3) [12.447(2)] Å, β = 98.19(2)° [97.36(1)]°, V = 849.72(3) [962.6(3)] Å3,z = 4, Dx = 2.925 [3.502] Mg m−3, R = 0.0525 [0.055], and Rw = 0.0554 [0.060] for 1151 [1472] observed reflections. Key words: MX3+ salts, FT–Raman spectroscopy, X-ray crystal structures of SeCl3AsF6, SBr3SbF6, and preparation of SeCl3SbF6.

Structural characterization of a new high-pressure phase of GaAsO4

2006 ◽  
Vol 62 (6) ◽  
pp. 1019-1024 ◽  
Author(s):  
David Santamaría-Pérez ◽  
Julien Haines ◽  
Ulises Amador ◽  
Emilio Morán ◽  
Angel Vegas
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Pressures ◽  
Ambient Conditions ◽  
Hexagonal Cell ◽  
Octahedral Sites ◽  
New Phase ◽  
Pressure Phase

As in SiO2 which, at high pressures, undergoes the α-quartz → stishovite transition, GaAsO4 transforms into a dirutile structure at 9 GPa and 1173 K. In 2002, a new GaAsO4 polymorph was found by quenching the compound from 6 GPa and 1273 K to ambient conditions. The powder diagram was indexed on the basis of a hexagonal cell (a = 8.2033, c = 4.3941 Å, V = 256.08 Å3), but the structure did not correspond to any known structure of other AXO4 compounds. We report here the ab initio crystal structure determination of this hexagonal polymorph from powder data. The new phase is isostructural to β-MnSb2O6 and it can be described as a lacunary derivative of NiAs with half the octahedral sites being vacant, but it also contains fragments of the rutile-like structure.

scholarly journals Identification and Characterization of ShSPI, a Kazal-Type Elastase Inhibitor from the Venom of Scolopendra Hainanum

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 708
Author(s):  
Ning Luan ◽  
Qiyu Zhao ◽  
Zilei Duan ◽  
Mengyao Ji ◽  
Meichen Xing ◽  
...  
Keyword(s):  
Human Neutrophils ◽  
Inhibitory Effects ◽  
Elastase Inhibitor ◽  
Endogenous Inhibitors ◽  
Venom Glands ◽  
Functional Peptides ◽  
20 Nm ◽  
Identification And Characterization ◽  
Cardiopulmonary System

Elastase is a globular glycoprotein and belongs to the chymotrypsin family. It is involved in several inflammatory cascades on the basis of cleaving the important connective tissue protein elastin, and is strictly regulated to a balance by several endogenous inhibitors. When elastase and its inhibitors are out of balance, severe diseases will develop, especially those involved in the cardiopulmonary system. Much attention has been attracted in seeking innovative elastase inhibitors and various advancements have been taken on clinical trials of these inhibitors. Natural functional peptides from venomous animals have been shown to have anti-protease properties. Here, we identified a kazal-type serine protease inhibitor named ShSPI from the cDNA library of the venom glands of Scolopendra hainanum. ShSPI showed significant inhibitory effects on porcine pancreatic elastase and human neutrophils elastase with Ki values of 225.83 ± 20 nM and 12.61 ± 2 nM, respectively. Together, our results suggest that ShSPI may be an excellent candidate to develop a drug for cardiopulmonary diseases.

Synthesis, Crystal Structure and Spectral Characterization, of a New Phase of Tris(phthalocyaninato)dibismuth(III), Bi2(Pc)3

2000 ◽  
Vol 2000 (8) ◽  
pp. 1771-1779 ◽  
Author(s):  
Karim Benihya ◽  
Mireille Mossoyan-Déneux ◽  
Friedemann Hahn ◽  
Nancy Boucharat ◽  
George Terzian
Keyword(s):  
Crystal Structure ◽  
Spectral Characterization ◽  
New Phase
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