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Tanatar MA Paglione J Nakatsuji S Hawthorn DG Boaknin E Hill RW Ronning F Sutherland M Taillefer L Petrovic C Canfield PC Fisk Z 《Physical review letters》2005,95(6):067002
Thermal conductivity and specific heat were measured in the superconducting state of the heavy-fermion material Ce(1-x)La(x)CoIn5. With increasing impurity concentration x, the suppression of T(c) is accompanied by the increase in residual electronic specific heat expected of a d-wave superconductor, but it occurs in parallel with a decrease in residual electronic thermal conductivity. This contrasting behavior reveals the presence of uncondensed electrons coexisting with nodal quasiparticles. An extreme multiband scenario is proposed, with a d-wave superconducting gap on the heavy-electron sheets of the Fermi surface and a negligible gap on the light, three-dimensional pockets. 相似文献
23.
Depending on protein environment, a single photofunctional chromophore shows a wide variation of photoabsorption/emission energies. This photobiological phenomenon, known as color tuning, is observed in human visual cone pigments, firefly luciferase, and red fluorescent protein. We investigate the origin of color tuning by quantum chemical calculations on the excited states: symmetry-adapted cluster-configuration interaction (SAC-CI) method for excited states and a combined quantum mechanical (QM)/molecular mechanical (MM) method for protein environments. This Minireview summarizes our theoretical studies on the above three systems and explains a common feature of their color-tuning mechanisms. It also discuss the possibility of artificial color tuning toward a rational design of photoabsorption/emission properties. 相似文献
24.
Yuya Nakatsuji Prof. Dr. Yusuke Kobayashi Sakyo Masuda Prof. Dr. Yoshiji Takemoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(8):2633-2637
Organo-radical catalysts have recently attracted great interest, and the development of this field can be expected to broaden the applications of organocatalysis. Herein, the first example of a radical-generating system is reported that does not require any photoirradiation, radical initiators, or preactivated substrates. The oxidative C−C-bond cleavage of 2-substituted cyclohexanones was achieved using an azolium salt and a hydroquinone as co-catalysts. A catalytic mechanism was proposed based on the results of diffusion-ordered spectroscopy and cyclic voltammetry measurements, as well as computational studies. 相似文献
25.
Kentaro Iwasaki Kazunori Umishita Shojun Hino Koichi Kikuchi Yohji Achiba 《Molecular Crystals and Liquid Crystals》2013,570(1):623-628
Abstract Ultraviolet photoelectron spectra of potassium dosed higher fullerenes are measured with a synchrotron radiation light source. Potassium dosing to higher fullerenes brings a new structure between the spectral onset of pristine fullerenes and the Fermi level. As the spectral edge of the new structure does not cross the Fermi level, potassium dosed higher fullerenes are not metallic but semiconductive. When the potassium is excessively dosed to the fullerenes, the lower binding energy structures above 5 eV become faint. In contrast to this phenomenon, four distinct structures appear between 5 and 14 eV. 相似文献
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The 304 Å HeII photoelectron (PE) spectrum of a mixture of NO2 and N2O4 in the gaseous phase has been measured in the region up to 29 eV. By subtracting the HeII spectrum of NO2 from the mixed spectrum, the HeII spectrum due to N2O4 has been deduced, indicating that there are three new PE bands in the region 20—29 eV. Relative band intensities have also been obtained from the HeII of N2O4 below 16 eV, corrected for electron collecting efficiency. 相似文献
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Yohji Nakatsuji Toshinori Inoue Masato Wada Mitsuo Okahara 《Journal of inclusion phenomena and macrocyclic chemistry》1991,10(3):379-386
A new type of 18-crown-6 derivative having two carboxylic acids on the side arms transported calcium and potassium ions in opposite directions across a dichloromethane membrane by pH control. Calcium and potassium ions were concentrated in the acidic and the basic phases, respectively. The presence of picrate ion in the acidic phase plays an important role in the transport of potassium ion from the acidic to the basic phase. 相似文献
30.
D. M. Poirier J. H. Weaver Koichi Kikuchi Yohji Achiba 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(1):79-83
X ray photoemission spectra show ~10 valence band features in C60 and C84 films, although they are less distinct in C84 because of the increased number of valence electrons and the decreased molecular symmetry. The presence of inequivalent carbon atoms in C84 is reflected by the fact that the C 1s main line is ~0.2 eV wider than in C60. The C 1s satellite region of C84 exhibits four features within 15 eV of the main line and shows that the HOMO-LUMO π-π* excitation energy of C84 is ~0.5 eV smaller than in C60. Potassium 2p spectra for K-doped C84 films suggest the formation of a phase with composition K3C84 with two spectroscopically-distinguishable K sites. A new spectral feature emerges when the K content is increased beyond K3C84, suggesting a phase transition and a saturated composition of K6C84, as for KxC60. These similarities are intriguing since KxC84 is insulating for all x while K3C60 is metallic and superconducting. 相似文献