126 research outputs found
Composition of primary cosmic rays at energies 10(15) to approximately 10(16) eV
The sigma epsilon gamma spectrum in 1 approx. 5 x 1000 TV observed at Mt. Fuji suggests that the flux of primary protons 10 to the 15 approx 10th eV is lower by a factor of 2 approx. 3 than a simple extrapolation from lower energies; the integral proton spectrum tends to be steeper than around to the power V and the spectral index tends to be steeper than Epsilon to the -17th power around 10 to the 14th power eV and the spectral index becomes approx. 2.0 around 10 to the 15th power eV. If the total flux of primary particles has no steepening up to approx 10 to the 15th power eV, than the fraction of primary protons to the total flux should be approx 20% in contrast to approx 45% at lower energies
Magnetic structure of CeRhIn_5 as a function of pressure and temperature
We report magnetic neutron-diffraction and electrical resistivity studies on
single crystals of the heavy-fermion antiferromagnet CeRhIn at pressures
up to 2.3 GPa. These experiments show that the staggered moment of Ce and the
incommensurate magnetic structure change weakly with applied pressure up to
1.63 GPa, where resistivity, specific heat and NQR measurements confirm the
presence of bulk superconductivity. This work places new constraints on an
interpretation of the relationship between antiferromagnetism and
unconventional superconductivity in CeRhIn.Comment: 6 pages, 6 figures, submitted to Phys. Rev.
Realization of odd-frequency p-wave spin-singlet superconductivity coexisting with antiferromagnetic order near quantum critical point
A possibility of the realization of the p-wave spin-singlet superconductivity
(SS), whose gap function is odd both in momentum and in frequency, is
investigated by solving the gap equation with the phenomenological interaction
mediated by the antiferromagnetic spin fluctuation. The SS is realized
prevailing over the d-wave singlet superconductivity (SS) in the vicinity of
antiferromagnetic quantum critical pint (QCP) both on the paramagnetic and on
the antiferromagnetic sides. Off the QCP in the paramagnetic phase, however,
the SS with line-nodes is realized as \textit{conventional} anisotropic
superconductivity. For the present SS state, there is no gap in the
quasiparticle spectrum everywhere on the Fermi surface due to its odd
frequency. These features can give a qualitative understanding of the anomalous
behaviors of NQR relaxation rate on CeCuSi or CeRhIn where the
antiferromagnetism and superconductivity coexist on a microscopic level.Comment: 20 pages with 12 figures. To appear in J. Phys. Soc. Jpn. Vol. 72,
No. 1
Quasiparticle spin susceptibility in heavy-fermion superconductors : An NMR study compared with specific heat results
Quasi-particle spin susceptibility () for various heavy-fermion
(HF) superconductors are discussed on the basis of the experimental results of
electronic specific heat (), NMR Knight shift () and NMR
relaxation rate () within the framework of the Fermi liquid model for a
Kramers doublet crystal electric field (CEF) ground state.
is calculated from the enhanced Sommerfeld coefficient and
from the quasi-particle Korringa relation
via the relation of
where is the hyperfine
coupling constant, the Abogadoro's number and the Bohr magneton.
For the even-parity (spin-singlet) superconductors CeCuSi, CeCoIn
and UPdAl, the fractional decrease in the Knight shift, , below the superconducting transition temperature () is due to
the decrease of the spin susceptibility of heavy quasi-particle estimated
consistently from and . This result
allows us to conclude that the heavy quasi-particles form the spin-singlet
Cooper pairs in CeCuSi, CeCoIn and UPdAl. On the other
hand, no reduction in the Knight shift is observed in UPt and
UNiAl, nevertheless the estimated values of and
are large enough to be probed experimentally. The odd-parity
superconductivity is therefore concluded in these compounds. The NMR result
provides a convincing way to classify the HF superconductors into either even-
or odd- parity paring together with the identification for the gap structure,
as long as the system has Kramers degeneracy.Comment: 11 pages, 3 tables, 5 figures, RevTex4(LaTex2e
Standardization of the Fabrication and the Operation Technologies for Large Scale Superconducting and Cryogenic Systems
Longer sleep is associated with lower BMI and favorable metabolic profiles in UK adults: Findings from the National Diet and Nutrition Survey
Ever more evidence associates short sleep with increased risk of metabolic diseases such as obesity, which may be related to a predisposition to non-homeostatic eating. Few studies have concurrently determined associations between sleep duration and objective measures of metabolic health as well as sleep duration and diet, however. We therefore analyzed associations between sleep duration, diet and metabolic health markers in UK adults, assessing associations between sleep duration and 1) adiposity, 2) selected metabolic health markers and 3) diet, using National Diet and Nutrition Survey data. Adults (n = 1,615, age 19–65 years, 57.1% female) completed questions about sleep duration and 3 to 4 days of food diaries. Blood pressure and waist circumference were recorded. Fasting blood lipids, glucose, glycated haemoglobin (HbA1c), thyroid hormones, and high-sensitivity C-reactive protein (CRP) were measured in a subset of participants. We used regression analyses to explore associations between sleep duration and outcomes. After adjustment for age, ethnicity, sex, smoking, and socioeconomic status, sleep duration was negatively associated with body mass index (-0.46 kg/m2 per hour, 95% CI -0.69 to -0.24 kg/m2, p < 0.001) and waist circumference (-0.9 cm per hour, 95% CI -1.5 to -0.3cm, p = 0.004), and positively associated with high-density lipoprotein cholesterol (0.03 mmol/L per hour, 95% CI 0.00 to 0.05, p = 0.03). Sleep duration tended to be positively associated with free thyroxine levels and negatively associated with HbA1c and CRP (p = 0.09 to 0.10). Contrary to our hypothesis, sleep duration was not associated with any dietary measures (p ≥ 0.14). Together, our findings show that short-sleeping UK adults are more likely to have obesity, a disease with many comorbidities
Sleep and energy intake in early childhood
Background And Objectives: Shorter sleep is associated with higher weight in children, but little is known about the mechanisms. The aim of this study was to test the hypothesis that shorter sleep was associated with higher energy intake in early childhood. Methods: Participants were 1303 families from the Gemini twin birth cohort. Sleep duration was measured using the Brief Infant Sleep Questionnaire when the children were 16 months old. Total energy intake (kcal per day) and grams per day of fat, carbohydrate and protein were derived from 3-day diet diaries completed by parents when children were 21 months old. Results: Shorter nighttime sleep was associated with higher total energy intake (P for linear trend=0.005). Children sleeping <10 h consumed around 50 kcal per day more than those sleeping 11–<12 h a night (the optimal sleep duration for children of this age). Differences in energy intake were maintained after adjustment for confounders. As a percentage of total energy intake, there were no significant differences in macronutrient intake by sleep duration. The association between sleep and weight was not significant at this age (P=0.13). Conclusions: This study provides the first evidence that shorter nighttime sleep duration has a linear association with higher energy intake early in life. That the effect is observed before emergence of associations between sleep and weight indicates that differences in energy intake may be a mechanism through which sleep influences weight gain
ヨウリョクタイガタ フェレドキシン ノ コウゾウ カイセキ 2.8Å ブンカイノウ
Remarkable progress in the physical parameters of net-current free plasmas has been made in the Large Helical Device (LHD) since the last Fusion Energy Conference in Chengdu, 2006 (O.Motojima et al., Nucl. Fusion 47 (2007) S668). The beta value reached 5 % and a high beta state beyond 4.5% from the diamagnetic measurement has been maintained for longer than 100 times the energy confinement time. The density and temperature regimes also have been extended. The central density has exceeded 1.0 x 10^21 m^-3 due to the formation of an Internal Diffusion Barrier (IDB). The ion temperature has reached 6.8 keV at the density of 2 x 10^19m^-3, which is associated with the suppression of ion heat conduction loss. Although these parameters have been obtained in separated discharges, each fusion-reactor relevant parameter has elucidated the potential of net-current free heliotron plasmas. Diversified studies in recent LHD experiments are reviewed in this paper
- …