Electron-energy-loss function of LiTaO3 and LiNbO3 by x-ray photoemission spectroscopy: Theory and experiment

We report experimental energy-loss structures in x-ray photoemission spectra of single crystalline LiTaO3 and LiNbO3, and then compare these with theoretical electron-energy-loss functions calculated from first principles using the full-potential linearized augmented plane-wave method in the local-density approximation. The energy-loss structure of core electrons can be approximated by a sum of four components: for LiTaO3, the peaks positioned at 8.0, 13.4, 15.8, and 22.6 eV; for LiNbO3, those positioned at 7.0, 12.0, 14.5, and 21.8 eV. The momentum matrix elements between Bloch functions were evaluated to determine the electron energy-loss functions. The theoretical electron-energy-loss functions agreed fairly well with the experimental one. The experimental peaks positioned at 8.0, 13.4, and 15.8 eV for LiTaO3 and those at 7.0, 12.0, and 14.5 eV for LiNbO3 were assigned to the interband transitions from the valence band to the conduction bands. The peaks at 22.6 eV for LiTaO3 and 21.8 eV for LiNbO3 were ascribed to the electron excitation from the O 2s level to the lower conduction band

Photoelectron energy-loss functions of SrTiO3, BaTiO3, and TiO2: Theory and experiment

We compare experimental O 1s electron energy-loss structures below 30 eV of single crystalline SrTiO3 ,BaTiO3, and TiO2 with their theoretical electron energy-loss functions. The photoelectron energy-loss structuresof in situ fractured surface in ultrahigh vacuum can be approximated by a sum of four components forSrTiO3 and BaTiO3, and of three components for TiO2. Electronic structures were calculated from first principlesusing the full-potential linearized augmented plane-wave method in the local-density approximation. Themomentum matrix elements between Bloch functions were evaluated to determine the electron energy-lossfunctions. The theoretical electron energy-loss functions agree well with experimental spectra except a structureat around 20 eV of SrTiO3 and that at around 18 eV of BaTiO3. The difference of high binding energypeaks is explained from the positions of semicore states

Electronic structure and electrical properties of amorphous OsO2

The valence-band spectrum of an amorphous OsO2 film deposited by glow discharge of OsO4 vapor can be predicted well with calculated electronic band structure of crystalline OsO2 from first principles using the liner-muffin-tin-orbital method with the local-density approximation. Resistivity of the amorphous OsO2 was less than 631023 V cm at 80 K, and it was almost temperature independent, but the temperature coefficient of resistivity was negative. The Hall coefficient of the amorphous OsO2 increased with temperature, and was saturated at around 220 K. Temperature dependence of the Hall mobility was proportional to T3/2, and it implies that the scattering of charged carriers by ionized atoms is dominant below 220 K

Frequency-dependent bifurcation point between field-cooled and zero-field-cooled dielectric constant of LiTaO3 nanoparticles embedded in amorphous SiO2

Splitting between the field-cooled dielectric constant and the zero-field-cooled dielectric constant was observed for a diluted system of LiTaO3 nanoparticles (diameter 30 Å) embedded in amorphous SiO2. At the applied field frequency of 100 kHz, the real part of the field-cooled dielectric constant diverged from that of the zero-field-cooled one at 380 °C. The bifurcation point of the history-dependent dielectric constant rose from 310 to 540 °C upon increasing the field frequency from 10 to 1000 kHz. Bulk LiTaO3 powders showed no splitting in the history-dependent dielectric constant and the maximum at 645 °C in the real part of the dielectric constant, despite the variation of frequency. Both the splitting of the history-dependent dielectric constant and the frequency dependence of the bifurcation point suggest that the LiTaO3 nanoparticles with a single-domain structure were in the superparaelectric state as a consequence of insignificant cooperative interactions among the nanoparticles in the diluted system. The energy barrier of 0.9 eV separating two (+p and –p) polarization states corroborated the potential of the LiTaO3 nanoparticle for ultrahigh-density recording media applications

Intensity Ratio of Kβ/Kα in Selected Elements from Mg to Cu, and the Chemical Effects of Cr Kα1,2 Diagram Lines and Cr Kβ/Kα Intensity Ratio in Cr Compounds

Y. Ito acknowledges the financial support for the measurements of a part of the data by the REXDAB Collaboration that was initiated within the International Fundamental Parameter Initiative. This research was supported in part by FCT (Portugal) under research center grants UID/FIS/04559/2020 (LIBPhys). This work was also supported by the National Science Centre, Poland under grant number 2017/25/B/ST2/00901 and grant number 2021/05/X/ST2/01664, and by the Slovenian Research Agency (P1-0112). A. Kahoul and A. Hamidani acknowledge the support of the DGRSDT, Ministry of Higher Education and Scientific Research, Algeria, and of Mohamed El Bachir El Ibrahimi University, under project (PRFU) No. B00L02UN340120220001. Paul Indelicato is a member of the Allianz Program of the Helmholtz Association, contract n° EMMI HA-216 “Extremes of Density and Temperature: Cosmic Matter in the Laboratory”. P.I. acknowledge support from the PESSOA Hubert Curien Program 2022, Number 47863UE. Publisher Copyright: © 2023 by the authors.(Formula presented.) X-ray lines from photon excitation were measured in selected elements from Mg to Cu using a high-resolution double-crystal X-ray spectrometer with a proportional counter, and the (Formula presented.) intensity ratio for each element was obtained, after correcting for self-absorption, detection efficiency, and crystal reflectance. This intensity ratio increases rapidly from Mg to Ca but, in the (Formula presented.) elements region, the increase becomes slower. This is related to the intensity of the (Formula presented.) line involving valence electrons. The slow increase of this ratio in the (Formula presented.) elements region is thought to be due to the correlation between (Formula presented.) and (Formula presented.) electrons. Moreover, the chemical shifts, FWHM, asymmetry indices, and (Formula presented.) intensity ratios of the Cr compounds, due to different valences, were also investigated using the same double-crystal X-ray spectrometer. The chemical effects were clearly observed, and the (Formula presented.) intensity ratio was found to be compound-dependent for Cr.publishersversionpublishe

Feeding Cues and Injected Nutrients Induce Acute Expression of Multiple Clock Genes in the Mouse Liver

The circadian clock is closely associated with energy metabolism. The liver clock can rapidly adapt to a new feeding cycle within a few days, whereas the lung clock is gradually entrained over one week. However, the mechanism underlying tissue-specific clock resetting is not fully understood. To characterize the rapid response to feeding cues in the liver clock, we examined the effects of a single time-delayed feeding on circadian rhythms in the liver and lungs of Per2::Luc reporter knockin mice. After adapting to a night-time restricted feeding schedule, the mice were fed according to a 4, 8, or 13 h delayed schedule on the last day. The phase of the liver clock was delayed in all groups with delayed feeding, whereas the lung clock remained unaffected. We then examined the acute response of clock and metabolism-related genes in the liver using focused DNA-microarrays. Clock mutant mice were bred under constant light to attenuate the endogenous circadian rhythm, and gene expression profiles were determined during 24 h of fasting followed by 8 h of feeding. Per2 and Dec1 were significantly increased within 1 h of feeding. Real-time RT-PCR analysis revealed a similarly acute response in hepatic clock gene expression caused by feeding wild type mice after an overnight fast. In addition to Per2 and Dec1, the expression of Per1 increased, and that of Rev-erbα decreased in the liver within 1 h of feeding after fasting, whereas none of these clock genes were affected in the lung. Moreover, an intraperitoneal injection of glucose combined with amino acids, but not either alone, reproduced a similar hepatic response. Our findings show that multiple clock genes respond to nutritional cues within 1 h in the liver but not in the lung

トクシマケン イシカイ トウニョウビョウ タイサクハン ダイ1ジ ダイ2ジ カツドウ ノ セイカ

Objective : The effectiveness of diabetes prevention programs for the general population in Tokushima Prefecture was investigated. The programs were designed by Tokushima Medical Association’ s（TMA’s）Steering Committee for Diabetes Prevention. Research design and methods : The committee promoted diabetes prevention by disseminating educational messages on diabetes to the general public and medical care providers, and establishing a referral system among public health centers and medical institutes throughout Tokushima Prefecture during the period from ２００４ to ２００９. The outcome of these activities were evaluated by analyzing data from the Prefectural Health and Nutrition Survey in Tokushima conducted in１９９７（n＝ ９９８）,２００３ （n＝１００８） and ２０１０ （n＝１１３０）, and then comparing these results with those of the national survey at the corresponding times. Results : The percentage of subjects with glucose intolerance at the time of initiation of the prevention program in Tokushima tended to increase from １９９７ to ２００３, but was slightly decreased in ２０１０, although the differences were not statistically significant. However, the percentage of subjects with glucose intolerance was significantly increased throughout Japan during the same period. Obesity parameters, physical activity evaluated by the number of steps and the average total energy intake changed favorably in parallel with changes in the prevalence of diabetes during the study period in Tokushima. Conclusion : The diabetes prevention programs initiated by the TMA’s committee may be useful in ameliorating the situation of diabetes in Tokushima Prefecture