Dynamical Screening and Superconducting State in Intercalated Layered Metallochloronitrides

An essential property of layered systems is the dynamical nature of the screened Coulomb interaction. Low energy collective modes appear as a consequence of the layering and provide for a superconducting-pairing channel in addition to the electron-phonon induced attractive interaction. We show that taking into account this feature allows to explain the high critical temperatures (Tc~26K) observed in recently discovered intercalated metallochloronitrides. The exchange of acoustic plasmons between carriers leads to a significant enhancement of the superconducting critical temperature that is in agreement with the experimental observations

Magnetic and superconducting properties on S-type single-crystal CeCu2_2Si2_2 probed by 63^{63}Cu nuclear magnetic resonance and nuclear quadrupole resonance

We have performed $^{63}$Cu nuclear magnetic resonance/nuclear quadrupole resonance measurements to investigate the magnetic and superconducting (SC) properties on a "superconductivity dominant" ($S$-type) single crystal of CeCu$_2$Si$_2$. Although the development of antiferromagnetic (AFM) fluctuations down to 1~K indicated that the AFM criticality was close, Korringa behavior was observed below 0.8~K, and no magnetic anomaly was observed above $T_{\rm c} \sim$ 0.6 K. These behaviors were expected in $S$-type CeCu$_2$Si$_2$. The temperature dependence of the nuclear spin-lattice relaxation rate $1/T_1$ at zero field was almost identical to that in the previous polycrystalline samples down to 130~mK, but the temperature dependence deviated downward below 120~mK. In fact, $1/T_1$ in the SC state could be fitted with the two-gap $s_{\pm}$-wave rather than the two-gap $s_{++}$-wave model down to 90~mK. Under magnetic fields, the spin susceptibility in both directions clearly decreased below $T_{\rm c}$, indicative of the formation of spin singlet pairing. The residual part of the spin susceptibility was understood by the field-induced residual density of states evaluated from $1/T_1T$, which was ascribed to the effect of the vortex cores. No magnetic anomaly was observed above the upper critical field $H_{c2}$, but the development of AFM fluctuations was observed, indicating that superconductivity was realized in strong AFM fluctuations.Comment: 10 pages, 8 figure

Structural Transition of Li2RuO3 Induced by Molecular-Orbit Formation

A pseudo honeycomb system Li2RuO3 exhibits a second-order-like transition at temperature T=Tc=540 K to a low-T nonmagnetic phase with a significant lattice distortion forming Ru-Ru pairs. For this system, we have calculated the band structure, using the generalized gradient approximation (GGA) in both the high- and low- T phases, and found that the results of the calculation can naturally explain the insulating behavior observed in the low-T phase. The detailed characters of the Ru 4d t2g bands obtained by the tight-binding fit to the calculated dispersion curves show clear evidence that the structural transition is driven by the formation of the Ru-Ru molecular-orbits, as proposed in our previous experimental studies.Comment: 5 pages, 5 figures, 4 tables, submitted to J. Phys. Soc. Jp

Adiabatic connection between the RVB State and the ground state of the half filled periodic Anderson model

A one-parameter family of models that interpolates between the periodic Anderson model with infinite repulsion at half-filling and a model whose ground state is exactly the Resonating-Valence-Bond state is studied. It is shown numerically that the excitation gap does not collapse. Therefore the ground states of the two models are adiabatically connected.Comment: 6 pages, 3 figures Revte

Risk of Fatigue Failure and Reliability of Intermittent Water Supply Pipelines

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Evaluation of the Chemical and Biological Characteristics of Sake Lees

Sake lees (SLs), produced from brewing Japanese Sake and known to be rich in yeast, is expected to be an alternative of feed protein sources for ruminants. Previous studies showed that yeast improved the digestibility of fibers in ruminants. However, the nutrient composition and the numbers of live and dead yeast in the SLs, have large diversity because of the different brewing materials and processes. The objective of this study was to evaluate the chemical and biological characteristics of SLs with diverse brewing processes and storing periods (0-23 weeks). Seven types of SLs (SLs 1-7) were collected from two breweries. SLs 1, 2, 5 and 6 were made from liquefied rice under high-temperature saccharification method and SLs 3, 4 and 7 were made from steamed rice under general multiple parallel fermentation method. The crude protein (CP) contents of SLs from liquefied rice were higher than those from steamed rice (59.3-69.9% vs 32.8-51.4%DM). Ethanol concentrations were in the range of 6.1 to 11.2%FM in SLs 1-5. The numbers of live yeast (×104 CFU/ FM g) were ranged from 1,462 to 6,109 before storing, which dramatically decreased to 0-145 at 4 weeks’ storing at 4℃ in SLs 1-5. The numbers of dead yeast (×109 / FM g) were ranged from 0.7 to 3.0 before storing, which were stable during 4 weeks’ storing showing 0.5-4.6 in SLs 1-5. These results suggested that SLs, especially from liquefied rice, had high CP contents and substantial amounts of ethanol. The live yeast observed drastically disappeared, on the other hand, the numbers of dead yeast were stable under refrigeration. Further study is needed to evaluate the effect of supplementary SLs on digestibility in ruminants especially in roughage feeding condition