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721.
Koji Nagata Tadao Nakamura Josep Batle Soliman Abdalla Ahmed Farouk 《International Journal of Theoretical Physics》2018,57(7):2116-2120
In the short contribution, we consider inequalities of confirming genuine multipartite entanglement. We have a better entanglement witness for a particular mixed state to test genuine multipartite entanglement. Our physical situation is that we measure Pauli observables σ x , σ y , and σ z per side. If the reduction factor is greater than 0.4, then we can confirm the measured quantum state is genuine multipartite entangled experimentally. 相似文献
722.
We numerically show that quasi-phase matched (QPM) lithium niobate (LN) devices employing the cascaded second-order nonlinear effect of second harmonic generation (SHG) and difference frequency mixing (DFM) have all-optical decision gate characteristics. The decision gate function is realized by a parabolic transmittance for a low-power region and a limiting characteristic for a high-power region. The limiter function is attributed to the large group-velocity mismatch between the fundamental and second harmonic pulses. This operation principle differs from those of other all-optical 2R (reamplification and reshaping) or 3R (2R and retiming) regenerators that have been proposed in the past. Furthermore, we show that an initial time offset between the signal and clock pulses can improve the output signal power or the switching efficiency of the device. Based on the numerical results, we propose a method for designing all-optical 3R regenerators using the cascade of SHG and DFM in the QPM-LN devices. Following the design method, all-optical 3R operation at the bit rate of 200 Gbps can be achieved using a 1-cm-long waveguide device. 相似文献
723.
724.
Tomohiko Nishiuchi Ryuoh Ito Aya Takada Yuri Yasuda Takaya Nagata Erik Stratmann Takashi Kubo 《化学:亚洲杂志》2019,14(10):1830-1836
Anthracene‐attached tricyclic aromatic hydrocarbon radicals having different central polygons, Ant‐5 , Ant‐6 , and Ant‐7 , were synthesized to evaluate the role of an anthracene substituent group in the stability and reactivity of tricyclic aromatic hydrocarbon radicals. The bulky anthryl group effectively protects a carbon atom with high spin density, resulting in high persistence of the radicals. On the other hand, the combination of the anthryl group and the tricyclic aromatic scaffold makes the molecular structure drastically change from a twisted form to a folded form and an unpaired electron moves into the anthryl moiety, eventually affording a tail‐to‐tail σ‐dimer. 相似文献
725.
A probability of electron-positron pair production by photons in strong nonuniform fields is derived by applying a model trajectory method in the frame of a semiclassical approach. In addition to the well known invariant field parameter chi, a new invariant parameter nu is introduced to characterize the nonuniformity of the field. For nu>1, the obtained expression is reduced to the uniform-field approximation while it approaches the Bethe-Heitler formula for nu<1. The pair production is predicted for relatively weak external fields where the uniform-field approximation gives no effect. The theory agrees well with the experimental results of crystal-assisted pair production. 相似文献
726.
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728.
Dr. Tomoya Miura Dr. Takayuki Nakamuro Yumi Ishihara Dr. Yuuya Nagata Prof. Dr. Masahiro Murakami 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20655-20659
An chiral RhII-catalyzed cyclooligomerization reaction of thiophenes having triazolyl and vinyl substituents at the 2- and 4-positions was studied. Structurally interesting cyclic trimers, having chirality that is ascribed only to the orientation of the 2,4-disubstituted thiophene rings, are obtained. The 2,4-disubstitution of the starting thiophene monomer allows production of each of the enantiomers. The observed electronic circular-dichroism spectra are in accord with those simulated by density-functional theory calculations. 相似文献
729.
Tomoaki Watanabe Yasuhiko Sakai Kouji Nagata Osamu Terashima Takashi Kubo 《Experiments in fluids》2012,53(5):1369-1383
This paper presents a new experimental approach for simultaneous measurements of velocity and concentration in a turbulent liquid flow with a chemical reaction. For the simultaneous measurements, we developed a combined probe consisting of an I-type hot-film probe and an optical fiber probe based on the light absorption spectrometric method. In a turbulent planar liquid jet with a second-order chemical reaction $(\mathrm{A}+\mathrm{B}\rightarrow \mathrm{R})$ , streamwise velocity and concentrations of all reactive species are measured by the combined probe. The turbulent mass fluxes of the reactive species are estimated from the simultaneous measurements. The results show that the influence of the chemical reaction on the turbulent mass flux of the reactant species near the jet exit is different from its influence in other regions, and the turbulent mass flux of the product species has a negative value near the jet exit and a positive value in other regions. 相似文献
730.
Naveen Kumar Kaliannan Andres Henao Aristizabal Hendrik Wiebeler Frederik Zysk Tatsuhiko Ohto Yuki Nagata 《Molecular physics》2020,118(4)
ABSTRACTWe have examined the impact of intermolecular vibrational coupling effects of the O-H stretch modes, as obtained by the surface-specific velocity-velocity correlation function approach, on the simulated sum-frequency generation spectra of the water/air interface. Our study shows that the inclusion of intermolecular coupling effects within the first three water layers, i.e. from the water/air interface up to a distance of 6?Å towards the bulk, is essential to reproduce the experimental SFG spectra. In particular, we find that these intermolecular vibrational contributions to the SFG spectra of the water/air interface are dominated by the coupling between the SFG active interfacial and SFG inactive bulk water molecules. Moreover, we find that most of the intermolecular vibrational contributions to the spectra originate from the coupling between double-donor water molecules only, whereas the remaining contributions originate mainly from the coupling between single-donor and double-donor water molecules. 相似文献