scholarly journals 3D X-ray tomographic analysis reveals how coesite is preserved in Muong Nong-type tektites

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Matteo Masotta ◽  
Stefano Peres ◽  
Luigi Folco ◽  
Lucia Mancini ◽  
Pierre Rochette ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Silica Glass ◽  
Spectroscopic Data ◽  
Multiscale Analysis ◽  
Nucleation Site ◽  
Vesicle Size ◽  
X Ray ◽  
Froth Layer ◽  
Post Shock ◽  
Tomographic Analysis

AbstractMuong Nong-type (MN) tektites are a layered type of tektite associated to the Australasian strewn field, the youngest (790 kyr) and largest on Earth. In some MN tektites, coesite is observed in association with relict quartz and silica glass within inclusions surrounded by a froth layer. The formation of coesite-bearing frothy inclusions is here investigated through a 3D textural multiscale analysis of the vesicles contained in a MN tektite sample, combined with compositional and spectroscopic data. The vesicle size distribution testifies to a post-shock decompression that induced melting and extensive vesiculation in the tektite melt. Compared to free vesicles, nucleated homogeneously in the tektite melt, froth vesicles nucleated heterogeneously on relict quartz surfaces at the margins of coesite-bearing inclusions. The rapid detachment of the froth vesicles and prompt reactivation of the nucleation site favoured the packing of vesicles and the formation of the froth structure. Vesicle relaxation time scales suggest that the vesiculation process lasted few seconds. The formation of the froth layer was instrumental for the preservation of coesite, promoting quenching of the inclusion core through the subtraction of heat during froth expansion, thereby physically insulating the inclusion until the final quench of the tektite melt.

Ablation Process of Silica Glass Induced by Laser Plasma Soft X-ray Irradiation

2009 ◽  
Vol 129 (4) ◽  
pp. 595-600
Author(s):  
Tetsuya Makimura ◽  
Takashige Fujimori ◽  
Shuichi Torii ◽  
Hiroyuki Niino ◽  
Kouichi Murakami
Keyword(s):  
Laser Plasma ◽  
Silica Glass ◽  
Ablation Process ◽  
X Ray

scholarly journals Phenylhydrazone and Quinazoline Derivatives from the Cold-Seep-Derived Fungus Penicillium oxalicum

Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 9
Author(s):  
Ya-Ping Liu ◽  
Sheng-Tao Fang ◽  
Zhen-Zhen Shi ◽  
Bin-Gui Wang ◽  
Xiao-Nian Li ◽  
...  
Keyword(s):  
Deep Sea ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
Penicillium Oxalicum ◽  
Marine Phytoplankton ◽  
Cold Seep ◽  
Phytoplankton Species ◽  
X Ray ◽  
X Ray Crystallography ◽  
Quinazoline Derivatives

Three new phenylhydrazones, penoxahydrazones A–C (compounds 1–3), and two new quinazolines, penoxazolones A (compound 4) and B (compound 5), with unique linkages were isolated from the fungus Penicillium oxalicum obtained from the deep sea cold seep. Their structures and relative configurations were assigned by analysis of 1D/2D NMR and mass spectroscopic data, and the absolute configurations of 1, 4, and 5 were established on the basis of X-ray crystallography or ECD calculations. Compound 1 represents the first natural phenylhydrazone-bearing steroid, while compounds 2 and 3 are rarely occurring phenylhydrazone tautomers. Compounds 4 and 5 are enantiomers that feature quinazoline and cinnamic acid units. Some isolates exhibited inhibition of several marine phytoplankton species and marine-derived bacteria.

scholarly journals Survey of Gravitationally Lensed Objects in HSC Imaging (SuGOHI) – VII. Discovery and confirmation of three strongly lensed quasars†

2021 ◽  
Vol 502 (1) ◽  
pp. 1487-1493
Author(s):  
Anton T Jaelani ◽  
Cristian E Rusu ◽  
Issha Kayo ◽  
Anupreeta More ◽  
Alessandro Sonnenfeld ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Point Sources ◽  
Sloan Digital Sky Survey ◽  
Early Type ◽  
Blue Point ◽  
X Ray ◽  
Quasar Spectra ◽  
Strategic Program ◽  
Early Type Galaxy

ABSTRACT We present spectroscopic confirmation of three new two-image gravitationally lensed quasars, compiled from existing strong lens and X-ray catalogues. Images of HSC J091843.27–022007.5 show a red galaxy with two blue point sources at either side, separated by 2.26 arcsec. This system has a source and a lens redshifts zs = 0.804 and zℓ = 0.459, respectively, as obtained by our follow-up spectroscopic data. CXCO J100201.50+020330.0 shows two point sources separated by 0.85 arcsec on either side of an early-type galaxy. The follow-up spectroscopic data confirm the fainter quasar has the same redshift with the brighter quasar from the Sloan Digital Sky Survey (SDSS) fiber spectrum at zs = 2.016. The deflecting foreground galaxy is a typical early-type galaxy at a redshift of zℓ = 0.439. SDSS J135944.21+012809.8 has two point sources with quasar spectra at the same redshift zs = 1.096, separated by 1.05 arcsec, and fits to the HSC images confirm the presence of a galaxy between these. These discoveries demonstrate the power of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP)’s deep imaging and wide sky coverage. Combined with existing X-ray source catalogues and follow-up spectroscopy, the HSC-SSP provides us unique opportunities to find multiple-image quasars lensed by a foreground galaxy.

Chromium implantation in silica glass

1996 ◽  
Vol 11 (1) ◽  
pp. 229-235 ◽  
Author(s):  
E. Cattaruzza ◽  
R. Bertoncello ◽  
F. Trivillin ◽  
P. Mazzoldi ◽  
G. Battaglin ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Silica Glass ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Secondary Ion Mass Spectrometry ◽  
Rutherford Backscattering Spectrometry ◽  
X Ray ◽  
Chromium Silicide ◽  
Secondary Ion

Silica glass was implanted with chromium at the energy of 35 and 160 keV and at fluences varying from 1 × 1016 to 11 × 1016 ions cm−2. In a set of chromium-implanted samples significant amounts of carbon were detected. Samples were characterized by x-ray photoelectron spectroscopy, x-ray-excited Auger electron spectroscopy, secondary ion mass spectrometry, and Rutherford backscattering spectrometry. Chromium silicide and chromium oxide compounds were observed; the presence of carbon in the implanted layers induces the further formation of chromium carbide species. Thermodynamic considerations applied to the investigated systems supply indications in agreement with the experimental evidences.

New iboga-type alkaloids from Ervatamia hainanensis

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30277-30284 ◽  
Author(s):  
Zhi-Wen Liu ◽  
Xiao-Jun Huang ◽  
Han-Lin Xiao ◽  
Guo Liu ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray

The structures and absolute configurations of seven new iboga-type alkaloids 1–7 were determined by spectroscopic data, Mosher's method, single crystal X-ray diffraction and ECD analyses.

Crotaleschenine, an Alkaloid of Crotalaria leschenaultii

1988 ◽  
Vol 41 (4) ◽  
pp. 429 ◽  
Author(s):  
LW Smith ◽  
JA Edgar ◽  
RI Willing ◽  
RW Gable ◽  
MF Mackay ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
X Ray ◽  
X Ray Crystallography

An alkaloid of Crotalaria leschenaultii DC., previously reported as crispatine and now named crotaleschenine, has been re-investigated and shown to be (7β,8α-H,12α,13α,14α)-12β-hydroxy-1,2-didehydrocrotalane-11,15-dione.1 Spectroscopic data are presented and the stereochemistry determined by X-ray crystallography. The esterifying acid of crotaleschenine is identical with that of retusine , which is thereby determined as (1a,7β,8α-H,12α,13α,14α)-12β- hydroxycrotalane-11,15-dione.

scholarly journals Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

2014 ◽  
Vol 10 ◽  
pp. 2021-2026 ◽  
Author(s):  
Henning Hopf ◽  
Swaminathan Vijay Narayanan ◽  
Peter G Jones
Keyword(s):  
Structural Analysis ◽  
Spectroscopic Data ◽  
Acid Treatment ◽  
Aldol Condensation ◽  
Membered Ring ◽  
X Ray

Under basic conditions 4,5,12,13-tetraacetyl[2.2]paracyclophane (9) cyclizes by a double aldol condensation to provide the two aldols 12 and 15 in a 3:7 ratio. The structures of these compounds were obtained from X-ray structural analysis, spectroscopic data, and mechanistic considerations. On acid treatment 12 is dehydrated to a mixture of the condensed five-membered [2.2]paracyclophane derivatives 18–20, whereas 15 yields a mixture of the isomeric cyclopentadienones 21–23. The structures of these elimination products are also deduced from X-ray and spectroscopic data. The sequence presented here constitutes the simplest route so far to cyclophanes carrying an annelated five-membered ring.

Tuning the topologies of Co(II) and Ni(II) complexes with EDTA, 1,3-PDTA and 1,4-BDTA ligands: Synthesis and spectroscopic data of [Mg(H2O)6][Co(1,4-bdta)]·3H2O and [Mg(H2O)6][Ni(1,4-bdta)]·3H2O complexes, and the X-ray structure of their chiral crystals

Polyhedron ◽  
2007 ◽  
Vol 26 (17) ◽  
pp. 4799-4808 ◽  
Author(s):  
Dušanka D. Radanović ◽  
Urszula Rychlewska ◽  
Beata Warżajtis ◽  
Milica S. Cvijović ◽  
Mirjana Dj. Dimitrijević ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
X Ray ◽  
Chiral Crystals
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