Results 121 to 130 of about 11,557,211 (324)

Radar observations of equatorial spread F in a region of electrostatic turbulence

, 1972
Radar observations of a welldeveloped layer of strong equatorial spread F are presented. The scattering cross section, correlation lifetime, and vertical electromagnetic drift velocity of the spread-F irregularities were measured as a function of ...
McClure, J. P., Woodman Pollitt, Ronald Francisco   +1 more
core   +1 more source

Iso‐Tellurazole N‐Oxides Assemble Adaptively Folded Macrocyclic Dodecamers

Chemistry – A European Journal, EarlyView.
Te…O Chalcogen bonding links twelve molecules into a ring that wraps itself around molecular guests. ABSTRACT Self‐assembled macrocyclic dodecamers were found in the crystals of new pseudo‐polymorphs of iso‐tellurazole N‐oxides. These structures are formed by molecules connected by NTe…O chalcogen bonds and are folded in a pattern that defines 89–153 ...
Jin Z. Wang, Phillip MacDougall, Mich W. Zeng, James F. Britten, Ignacio Vargas‐Baca   +4 more
wiley   +1 more source

Vibrational Circular Dichroism Spectra of 2,5‐Diaminoterephtalate Macrocycles Reveal Distant Vibrational Exciton Coupling

Chemistry – A European Journal, EarlyView.
The energy level diagrams for the ν(C═O) and the δ(N─H) vibrations, resulting of combining in‐phase and out‐of‐phase modes on the basis of their local symmetries, was built by applying the exciton coupling theory to a new class of chiral macrocycles, based on the 2,5‐diaminoterephthalate scaffold.
Samara Medina, Krzysztof Nowak, Marek Grzybowski, Juan Casado, Francisco J. Ramírez   +4 more
wiley   +1 more source

Features of 3–7-day planetary-wave-type oscillations in F-layer vertical drift and equatorial spread F observed over two low-latitude stations in China

, 2017
. Recent studies on the equatorial atmosphere–ionosphere coupling system have shown that planetary-wave-type oscillations, as an important seeding mechanism for equatorial spread F (ESF), play an important role in ESF irregularity development and its day-
Zhengping Zhu, Weihua Luo, Jia-Ping Lan, Shan-Shan Chang   +3 more
semanticscholar   +1 more source

Hydrogen Release From Silicon─Hydrogen Systems: From Surface Chemistry to Higher‐Coordinate Molecular Mechanisms

Chemistry – A European Journal, EarlyView.
Hydrogen‐release processes in silicon chemistry occur across a broad spectrum of systems, including crystalline silicon surfaces, nanoporous materials, Zintl phases, and molecular hydrides. This Review highlights how Si─H activation and H2 evolution are governed by structure, coordination environment, and dynamic access to reactive geometries, with ...
Robin Rothfelder, Jonathan O. Bauer
wiley   +1 more source

Readily Accessible bTurea‐Derived Nitroxide Polarizing Agents for Dynamic Nuclear Polarization: bcTCOOKs and bcTmols

Chemistry – A European Journal, EarlyView.
Two families of bTurea‐derived biradicals, bcTmols and bcTCOOKs, were prepared as polarizing agents for dynamic nuclear polarization (DNP)‐enhanced NMR through short and efficient synthetic routes. The best‐performing biradical, bcTCOOK‐M2, containing two methyl groups on the urea bridge, provided signal enhancements of up to ∼220 at 14.1 T and 100 K ...
Ancy T. Wilson, Shubha S. Gunaga, Frederic Mentink‐Vigier, Snorri Th. Sigurdsson   +3 more
wiley   +1 more source

Persilylated and Related Silyl Anion‐Induced Synthesis of Group 3–10 Metal–Silyl Complexes

Chemistry – A European Journal, EarlyView.
Persilylated and related silyl anions serve as powerful tools for constructing metal–silyl complexes across group 3–10 elements. Their strong σ‐donating ability and steric bulk stabilize low‐coordinate, reactive species and enable unique bonding motifs.
Yusuke Sunada
wiley   +1 more source

Learned Regularizations for Multi‐Parameter Elastic Full Waveform Inversion Using Diffusion Models

Journal of Geophysical Research: Machine Learning and Computation
Elastic full waveform inversion (EFWI) promises to account for the Earth's elastic nature and corresponding reflectivity, which is often disregarded in the commonly used acoustic FWI.
Mohammad H. Taufik, Fu Wang, Tariq Alkhalifah   +2 more
doaj   +1 more source

Reduction Process of Pt(IV) Complexes With Axial Acetato Ligands by Ascorbic Acid; Comparison of Experimental and Computational Tools

Chemistry – A European Journal, EarlyView.
Comparison of experimental and calculated rate constants for reduction of selected Pt(IV) complexes by ascorbic acid (AA) in water solution at pH = 7. ABSTRACT In the present work, the reduction mechanism of several Pt(IV) complexes bearing two axial acetato ligands by ascorbic acid (AA) was investigated.
Ondřej Tichý, Patrick A. Yassemipour, Christian R. Kowol, Jaroslav V. Burda   +3 more
wiley   +1 more source

A Solid‐Phase Approach to Chiral C2‐Substituted Cyclen and DOTA‐Like Lanthanoid Ligands

Chemistry – A European Journal, EarlyView.
Chiral C2‐substituted cyclen derivatives have been designed and synthesized from chiral cyclic peptoids. Their conversion into the corresponding DOTA‐type ligands opens new avenues for the development of high‐relaxivity MRI contrast agents. ABSTRACT Magnetic resonance imaging (MRI) is a powerful diagnostic modality that relies on Gd+3‐based contrast ...
Rosaria Schettini, Roberta Napolitano, Alberto Fringuello Mingo, Federica Buonsanti, Giovanni Pierri, Consiglia Tedesco, Chiara Costabile, Giorgio Della Sala, Irene Izzo, Francesco De Riccardis   +9 more
wiley   +1 more source