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We have successfully grown centimeter-sized layered $$\textit{R}\mathrm{SrNiO}_{4}$$ R SrNiO 4 single crystals under high oxygen pressures of 120–150 bar by the floating zone technique. This enabled us to perform neutron scattering experiments where we observe close to quarter-integer magnetic peaks below $$\sim 77~\mathrm{K}$$ ∼ 77 K that are accompanied by steep upwards dispersing spin excitations. Within the high-frequency Ni–O bond stretching phonon dispersion, a softening at the propagation vector for a checkerboard modulation can be observed. We were able to simulate the magnetic excitation spectra using a model that includes two essential ingredients, namely checkerboard charge disproportionation and nano phase separation. The results thus suggest that charge disproportionation is preferred instead of a Jahn–Teller distortion even for this layered $$\mathrm{Ni}^{3+}$$ Ni 3 + system.

As an important branch of artificial intelligence, machine learning is widely used in various fields. Machine learning has similarity to classical statistical methods, but can solve many problems which are difficult for traditional statistics, so it is one of the important tools in epidemiological research. This paper introduced 9 common algorithms of machine learning and summarized their characteristics and applications in epidemiological research. Readers could choose appropriate machine learning method according to the research purpose for the better application of machine learning in epidemiological research.机器学习作为人工智能的重要分支之一，广泛运用于各个领域。机器学习与经典统计学方法有相似之处，同时又能解决许多传统统计学难以处理的难题，因此是流行病学研究的重要工具之一。本文介绍了几种机器学习的常用算法，并对其特点和在流行病学研究中的应用进行了总结。读者可根据研究目的选择适当的机器学习方法，让机器学习技术更好地为流行病学研究服务。.

Temperature-dependent X-ray absorption near-edge structures, X-ray linear dichroism (XLD) and extended X-ray absorption fine structure (EXAFS) spectroscopic techniques were used to investigate the valence state, preferred orbital and local atomic structure that significantly affect the electrical and magnetic properties of a single crystal of YBaCuFeO5 (YBCFO). An onset of increase of resistivity at ~180 K, followed by a rapid increase at/below 125 K, is observed. An antiferromagnetic (AFM)-like transition is close to the temperature at which the resistivity starts to increase in the ab-plane and is also observed with strong anisotropy between the ab-plane and the c-axis. The XLD spectra at the Fe L3,2-edge revealed a change in Fe 3d eg holes from the preferential $${\bf{3}}{{\boldsymbol{d}}}_{{{\bf{x}}}^{{\bf{2}}}{\boldsymbol{-}}{{\bf{y}}}^{{\bf{2}}}}$$3dx2−y2 orbital at high temperature (300–150 K) to the $${\bf{3}}{{\boldsymbol{d}}}_{{{\bf{3}}{\bf{z}}}^{{\bf{2}}}{\boldsymbol{-}}{{\bf{r}}}^{{\bf{2}}}}$$3d3z2−r2 orbital at/below 125 K. The analysis of the Fe K-edge EXAFS data of YBCFO further revealed an unusual increase in the Debye-Waller factor of the nearest-neighbor Fe-O bond length at/below 125 K, suggesting phonon-softening behavior, resulting in the breaking of lattice symmetry, particularly in the ab-plane of Fe-related square pyramids. These findings demonstrate a close correlation between electrical resistivity and coupling of the preferred Fe 3d orbital with lattice distortion of a single crystal of YBCFO.

A new Ba2CuO4-y superconductor with critical temperature (Tc) exceeding 70 K was discovered. The X-ray absorption measurement gives evidence that this cuprate resembles La2CuO4 but is doped with a fairly large amount of holes, while in contrast to the so far known hole-doped high-Tc cuprates, the new cuprate possesses a much shorter local apical oxygen distance as well as much expanded in-plane Cu–O bond, leading to unprecedented compressed local octahedron. In compressed local octahedron, the Cu3d3z2–r2 orbital level will be lifted above the Cu3dx2-y2 orbital level with more three-dimensional features, implying that pairing symmetry may carry admixtures from more than one gap, suggesting that Ba2CuO4-y composed of alkaline earth copper oxides that are the essential elements to form cuprate superconductors may belong to a new branch of cuprate superconductors.

The mechanism of superconductivity in cuprates remains one of the big challenges of condensed matter physics.High Tc cuprates crystallize into layered perovskite structure featuring copper oxygen octahedral coordination. Due to the Jahn Teller effect in combination with the strong static Coulomb interaction, the octahedra in high Tc cuprates are elongated along the c axis, leading to a 3dx2-y2 orbital at the top of the band structure wherein the doped holes reside.This scenario gives rise to two dimensional characteristics in high Tc cuprates that favor d wave pairing symmetry. Here we report superconductivity in a cuprate Ba2CuO4-y wherein the local octahedron is in a very exceptional compressed version.The Ba2CuO4-y compound was synthesized at high pressure at high temperatures, and shows bulk superconductivity with critical temperature Tc above 70 K at ambient conditions. This superconducting transition temperature is more than 30 K higher than the Tc for the isostructural counterparts based on classical La2CuO4. X-ray absorption measurements indicate the heavily doped nature of the Ba2CuO4-y superconductor. In compressed octahedron the 3d3z2-r2 orbital will be lifted above the 3dx2-y2 orbital, leading to significant three dimensional nature in addition to the conventional 3dx2-y2 orbital. This work sheds important new light on advancing our comprehensive understanding of the superconducting mechanism of high Tc in cuprate materials., Comment: Total 28 pages incuding 9 Figures

In this study, a simple and rapid method was developed for the determination of BHT (2,6-di-t-butyl-p-hydroxytoluene) and BHA (t-butyl-4-hydroxyanisole) in chewing gum using solvent extraction combined with gas chromatography. The results showed that among seven types of extraction solvent, diethyl ether was the best, as chewing gum dissolved and dispersed in diethyl ether, gave the highest yield of BHT and BHA from chewing gum. Recovery studies were performed on chewing gum, spiked with both BHT and BHA at 100~200µg/g each. The recoveries of both BHT and BHA were 99~101% (CV: 1.5~3.2%) and 94~99% (CV: 7.1~8.6), respectively. The coefficients of variation were less than 8.6%. Fifteen chewing gum samples were analyzed by the current method. Both the BHT and BHA contents were found to be 0~296 µg/g and 0~133 µg/g, respectively. After chewing for 15 min, 70% of the total soluble compounds and 50% of BHT and BHA were released from chewing gum.

A simple and rapid method was developed to simultaneously determine the nicotinamide, paraben as well as caffeine by using megapore immediate-polar column (CP-Sil 24CB, 30 m × 0.53 mm, 1.5 μm) with direct injection gas chromatography. Direct quantitative analysis of nicotinamide, paraben esters and caffeine in health drinks, tonic drinks, and cold formulas was carried out without any sample pretreatment procedure. The water soluble compound 1,9-nonanediol was used as an internal standard. The detection limit for nicotinamide, paraben esters and caffeine was 2 μg/mL. Recovery studies were performed using 1 mL of vitamin B drink, tonic drink and cold solution, each spiked with nicotinamide, paraben esters and caffeine at 100.0 μg, respectively. The recoveries for nicotinamide were 96, 102 and 105%, respectively, and the coefficient of variation was less than 7.2%. The recoveries for butylparaben were 105, 95, and 107%, respectively, and the coefficient of variation was less than 8.3%. The recoveries for caffeine were 101, 95 and 104%, respectively, and the coefficient of variation was less than 7.5%. Fifty-two commercial health drinks, tonic drinks and cold solutions were analyzed by the current method. The nicotinamide content was found as: 20.3-241.7, 0-210.7 and 0-246.8 μg/mL, respectively; the isobutylparaben content was found as: 0-54.1, 0-42.9 and 0-134.1 mg/mL; the butylparaben content was found as: 0-106.8, 0-120.1 and 0-184.6 μg/mL; and the caffeine content was found as: 0-433.2, 0-80.7 and 472.3-1742.9 μg/mL. These results indicated that 6 out of 18 commercial health drinks, 2 out of 12 commercial tonic drinks, and 2 out of 22 commercial cold formulas exceeded the Taiwan nicotinamide recommended daily nutrient allowances (RDNA, 14.4 μg) level. Furthermore, 25 out of 52 samples labeled “preservative-free” were detected to be preservative-containing products. The total preservative contents in some test samples exceeded the regulation levels of 100 μg/mL; and 27 out of 30 samples were detected to be caffeine-containing products. These results were inconsistent with the CNS (Chinese National Standard) rules.

We have successfully grown centimeter-sized layered \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textit{R}\mathrm{SrNiO}_{4}$$\end{document}RSrNiO4 single crystals under high oxygen pressures of 120–150 bar by the floating zone technique. This enabled us to perform neutron scattering experiments where we observe close to quarter-integer magnetic peaks below \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim 77~\mathrm{K}$$\end{document}∼77K that are accompanied by steep upwards dispersing spin excitations. Within the high-frequency Ni–O bond stretching phonon dispersion, a softening at the propagation vector for a checkerboard modulation can be observed. We were able to simulate the magnetic excitation spectra using a model that includes two essential ingredients, namely checkerboard charge disproportionation and nano phase separation. The results thus suggest that charge disproportionation is preferred instead of a Jahn–Teller distortion even for this layered \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{Ni}^{3+}$$\end{document}Ni3+ system.

Summary Background Increased blood pressure is the biggest contributor to the global burden of disease and mortality. Data suggest that less than half of the population with hypertension is aware of it. May Measurement Month was initiated to raise awareness of the importance of blood pressure and as a pragmatic interim solution to the shortfall in screening programmes. Methods This cross-sectional survey included volunteer adults (≥18 years) who ideally had not had their blood pressures measured in the past year. Each participant had their blood pressure measured three times and received a a questionnaire about demographic, lifestyle, and environmental factors. The primary objective was to raise awareness of blood pressure, measured by number of countries involved, number of people screened, and number of people who have untreated or inadequately treated hypertension (defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg, or both, or on the basis of receiving antihypertensive medication). Multiple imputation was used to estimate the mean of the second and third blood pressure readings if these were not recorded. Measures of association were analysed using linear mixed models. Findings Data were collected from 1 201 570 individuals in 80 countries. After imputation, of the 1 128 635 individuals for whom a mean of the second and third readings was available, 393 924 (34·9%) individuals had hypertension. 153 905 (17·3%) of 888 616 individuals who were not receiving antihypertensive treatment were hypertensive, and 105 456 (46·3%) of the 227 721 individuals receiving treatment did not have controlled blood pressure. Significant differences in adjusted blood pressures and hypertension prevalence were apparent between regions. Adjusted blood pressure was higher in association with antihypertensive medication, diabetes, cerebrovascular disease, smoking, and alcohol consumption. Blood pressure was higher when measured on the right arm than on the left arm, and blood pressure was highest on Saturdays. Interpretation Inexpensive global screening of blood pressure is achievable using volunteers and convenience sampling. Pending the set-up of systematic surveillance systems worldwide, MMM will be repeated annually to raise awareness of blood pressure. Funding International Society of Hypertension, Centers for Disease Control and Prevention, Servier Pharmaceutical Co.

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, transethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N = 78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P

Owing to the current energy crisis and extreme changes in the global climate, there is great interest in finding renewable energy resources. Vast progress has been made in the development of new materials related to renewable energy, and their physical/chemical properties can be tailored by nanostructuring and other advanced synthetic approaches. In many important energy systems, such as solar hydrogen systems, the atomic/electronic structures of materials and fundamental interfacial phenomena of systems critically determine the energy conversion efficiency of materials [1, 2]. Without knowledge of the fundamental electronic structures of the materials during conversion reactions, better engineering of the material for practical use is difficult. Understanding and controlling the interfaces in energy generation/conversion/storage materials requires in-situ/operando approaches [3, 4]. The Taiwan Photon Source (TPS) Soft X-ray Spectroscopic beamline provides the capabilities for X-ray absorption (XAS) and X...

In this study, effect of calcium ions on the filtration behaviors of alginate solution and its underlying mechanisms were systematically investigated. It was found that, the filtration resistance of the formed gel layer and the specific filtration resistance (SFR) of alginate solution showed an unimodal pattern with increase in Ca2+ concentration, and the maximal SFR was as extremely high as 3.63×1015 m·kg-1. Series analyses showed that Ca2+ concentration exerted no apparent impact on pore clogging resistance, composition of functional groups and elements of the formed gel. In contrary, increase in Ca2+ concentration caused transitions of colloid formation and alginate polymer micromorphology in solution, well corresponding to the unimodal pattern of filtration behaviors. It was proposed that, Flory-Huggins mechanism governed the extremely high SFR of the alginate gel. Meanwhile, it was suggested that initial calcium binding by alginate occurred in intermolecular rather than intramolecular, which was the key mechanism governing the development of micromorphology and SFR of alginate gel with increase in Ca2+ concentration. These findings offered deep insights into alginate gel fouling associated with calcium ions, and also gave implications to membrane fouling control in membrane bioreactors.

Quantification of interfacial interaction with randomly rough surface is the prerequisite to quantitatively understand and control the interface behaviors such as adhesion, flocculation and membrane fouling. In this study, it was found that membrane surface was randomly rough with obvious fractal characteristics. The randomly rough surface of membrane could be well reconstructed by the fractal geometry represented by a modified Weierstrass-Mandelbrot function. A novel method, which combined composite Simpson's approach, surface element integration method and approximation by computer programming, was developed. By using this method, this study provided the first realization of quantifying interfacial energy between randomly rough surface of membrane and a foulant particle. The calculated interactions with randomly rough surface of membrane were significantly different from those with smooth surface of membrane, indicating the significant effect of surface topography on interactions. This proposed method could be also potentially used to investigate various natural interface environmental phenomena.

We have synthesized single crystals of dolerophanite ${\mathrm{Cu}}_{2}{\mathrm{OSO}}_{4}$ by means of chemical vapor transport and studied the direction-dependent magnetic susceptibility and dielectric properties of this low-dimensional $S=1/2$ system. Below the magnetic ordering temperature of $\ensuremath{\sim}20$ K, we observe an unusually strong ferromagnetic component of roughly 1/4 ${\ensuremath{\mu}}_{B}$ per ${\mathrm{Cu}}^{2+}$ ion along the $b$ direction, parallel to the zigzag chains of copper-oxygen square plaquettes. It is also remarkable that the onset of magnetic ordering can be enhanced by about 20% if an external magnetic field is applied along the direction of these chains.

$B$-site ordered thin films of double perovskite ${\mathrm{Sr}}_{2}{\mathrm{CoIrO}}_{6}$ were epitaxially grown by a metalorganic aerosol deposition technique on various substrates, actuating different strain states. X-ray diffraction, transmission electron microscopy, and polarized far-field Raman spectroscopy confirm the strained epitaxial growth on all used substrates. Polarization-dependent Co ${L}_{2,3}$ x-ray absorption spectroscopy reveals a change of the magnetic easy axis of the antiferromagnetically ordered (high-spin) ${\mathrm{Co}}^{3+}$ sublattice within the strain series. By reversing the applied strain direction from tensile to compressive, the easy axis changes abruptly from in-plane to out-of-plane orientation. The low-temperature magnetoresistance changes its sign respectively and is described by a combination of weak antilocalization and anisotropic magnetoresistance effects.

The interactions of energetic ions with multi-cation compounds and their consequences in terms of changes in the local electronic structure, which may facilitate intriguing hybridization between O 2p and metal d orbitals and magnetic ordering, are the subject of debate and require a deep understanding of energy transfer processes and magnetic exchange mechanisms. In this study, nanocrystals of ZnFe2O4 were exposed to O7+ ions with an energy of 100 MeV to understand, qualitatively and quantitatively, the metal-ligand field interactions, cation migration and magnetic exchange interactions by employing X-ray absorption fine structure measurements and X-ray magnetic circular dichroism to get deeper mechanistic insights. Nanosized zinc ferrite nanoparticles (NPs) with a size of ∼16 nm synthesized in the cubic spinel phase exhibited deterioration of the crystalline phase when 100 MeV O7+ ions passed through them. However, the size of these NPs remained almost the same. The behaviour of crystal deterioration is associated with the confinement of heat in this interaction. The energy confined inside the nanoparticles promotes cation redistribution as well as the modification of the local electronic structure. Prior to this interaction, almost 42% of Zn2+ ions occupied AO4 tetrahedra; however, this value increased to 63% after the interaction. An inverse effect was observed for metal ion occupancies in BO6 octahedra. The L-edge spectra of Fe and Zn reveal that the spin and valence states of the metal ions were not affected by this interaction. This effect is also supported by K-edge measurements for Fe and Zn. The t2g/eg intensity ratio in the O K-edge spectra decreased after this interaction, which is associated with detachment of Zn2+ ions from the lattice. The extent of hybridization, as estimated from the ratio of the post-edge to the pre-edge region of the O K-edge spectra, decreased after this interaction. The metal-oxygen and metal-metal bond lengths were modified as a result of this interaction, as determined from extended X-ray absorption fine structure measurements. These measurements further support the observation of cation migration from AO4 tetrahedra to AO6 octahedra and vice versa. The Fe L-edge magnetic circular dichroism spectra indicate that Fe3+ ions occupying sites in AO4 tetrahedra and BO6 octahedra exhibited antiferromagnetic-like ordering prior to this interaction. The NPs that interacted with energetic O ions displayed a different kind of magnetic ordering.