Results 101 to 110 of about 208,746 (285)

Exploring the Boundaries of Aromaticity in Complex Structures and Excited States Through Computational Analysis

Chemistry – A European Journal, EarlyView.
Understanding aromaticity has evolved from benzene‐centric concepts to a broad multidimensional framework spanning organic, inorganic, and excited‐state systems. This review highlights ambiguities between magnetic, electronic, geometric, and energetic descriptors, emphasizing the need for unified, multi‐criteria approaches.
Sílvia Escayola, Miquel Solà, Albert Poater   +2 more
wiley   +1 more source

Designing a Triplet 2‐Formylphenylnitrene With Fast Tunneling Reactivity

Chemistry – A European Journal, EarlyView.
A 3‐CF3 substituent accelerates tunneling in triplet 2‐formylphenylnitrene, making its reactivity in cryogenic matrices too fast for conventional IR spectroscopic detection. Bringing this chemistry to low‐temperature solutions allows suppression of intrinsic nitrene dimerization through faster cyclization, which even outcompetes the 1,4‐H shift ...
Sofia Braz, Cláudio M. Nunes, Simon Schlosser, Peter R. Schreiner, Rui Fausto   +4 more
wiley   +1 more source

Foldamers With Two Distinct Helical Motifs Controlled by Solvent

Chemistry – A European Journal, EarlyView.
Alternating o‐phenylene and 2,3‐pyrazinylene oligomers were synthesized and their conformational behavior studied by NMR spectroscopy, x‐ray crystallography, and DFT calculations. They fold into well‐defined helices, but, remarkably, the folding motif depends on solvent: a compact helix in chloroform, but a much longer extended helix in acetone ...
Yinhui Liao, Vipul Batra, Govinda Prasad Devkota, Annabelle Ryu, Henry S. Oliver, David L. Tierney, C. Scott Hartley   +6 more
wiley   +1 more source

FEM Modeling of Coupled Modes Vibrations and Rock-Cutting Elements Wear in Percussive–Rotary Drilling of Geological Materials

Vibration
Downhole vibrations are a primary cause of premature wear and failure of rock-cutting elements (RCEs) during well drilling. This study develops an integrated finite element (FEM) model that couples axial and torsional vibrations with the evolution of the
Oleksandr Pashchenko, Yevhenii Koroviaka, Volodymyr Khomenko, Oleksandr Kamyshatskyi, Valerii Rastsvietaiev, Serhii Shypunov   +5 more
doaj   +1 more source

Monitoramento sem fio da vibração torsional de powertrain automotivo [PDF]

, 2015
TCC (graduação) - Universidade Federal de Santa Catarina. Campus Joinville. Engenharia Mecatrônica.A instalação de sensores para a medição da vibração torsional em diversos pontos do powertrain se faz necessária em testes veiculares, o que consome tempo ...
Korol, Daniel Rossi
core  

Benzylic Oxidation of Pillar[5]Arene: From Homo‐ to Cross‐Conjugated Macrocyclic Systems

Chemistry – A European Journal, EarlyView.
Selective benzylic oxidations of pillar[5]arene have been carried out to generate all the possible oxidized derivatives containing from one up to five carbonyl subunits. Effects resulting from the homo‐ and the cross‐conjugation within this series of compounds have been investigated in details and analyzed with the help of DFT calculations.
Jorge Juan Marco‐Guimbao, Eric Meichsner, Unai Calvo, Michel Holler, Béatrice Delavaux‐Nicot, Jon M. Matxain, Juan Luis Delgado, Jean‐François Nierengarten, Iwona Nierengarten   +8 more
wiley   +1 more source

Boron Monofluoride Complexes Bearing π‐Expanded Coumarin Subunits: Facile Synthesis, Crystal Structure, and Solid‐State Enhanced Emission

Chemistry – A European Journal, EarlyView.
We here report the design, facile synthesis, experimental, and theoretical characterization of a novel class of monofluoroborate compounds featuring π‐expanded coumarin subunits displaying solid‐state enhanced Emission. The origin of this phenomenon is disclosed by combined theoretical and spectroscopic investigations.
Amine Assel, Fausto Puntoriero, Mohamed Chellegui, Antonio Santoro, Francesco Nicolò, Mayssa Zayene, Hichem Ben Jannet, Alessandro Auditore, Tianhong Yan, Alessandro Amadeo, Frédéric Labat, Ilaria Ciofini, Sebastiano Campagna   +12 more
wiley   +1 more source

Numerical simulation study on the characteristics and propagation attenuation of vibration signals in freezing pipe fracture

Deep Underground Science and Engineering, EarlyView.
This research study employs analysis system (ANSYS) fluid–structure interaction simulations to investigate the generation and attenuation of vibration signals resulting from freezing pipe fractures in artificial ground freezing projects. By evaluating key variables—including frozen soil elastic modulus, brine inlet pressure, and external pipe pressure ...
Yi Cao, Yansen Wang, En Chen, Meng Zhao
wiley   +1 more source

ALGORITHMS FOR SOFTWARE COMPENSATION OF TORSIONAL VIBRATIONS IN H-BOT 3D PRINTERS BASED ON FILTERED B-SPLINES

Шәкәрім университетінің хабаршысы: Техника ғылымдар
The rapid development of additive manufacturing technologies imposes increasingly stringent requirements on the positioning accuracy and dynamic stability of motion systems, particularly in printers employing H-bot kinematic architectures, which are ...
A. Kenzhebay, A. Tynykulova, G. Yensebayeva, S. Zhakypbekov, K. Bakenova   +4 more
doaj   +1 more source

Synergistic Molecular Engineering and Crosslinking Topology for High‐Temperature Energy Storage in All‐Organic Dielectrics

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
A synergistic strategy combining CF3 group incorporation and crosslinking topology is employed to tailor chain spacing and local ordering in all‐organic dielectrics. This design effectively suppresses carrier migration and enhances polarization, yielding outstanding high‐temperature energy storage performance (e.g., 8.95 J cm−3 with 90% efficiency at ...
Xu Tong, Xue Zhang, Tiandong Zhang, Changhai Zhang, Zhiqi Zhou, Tongqin Zhang, Jiaqi Zhang, Chao Wang, Yue Zhang, Yongquan Zhang, Qingguo Chi   +10 more
wiley   +1 more source