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Lead hafnate (PbHfO3) has attracted a lot of renewed interest due to its potential as antiferroelectric (AFE) material for energy storage. However, its room temperature (RT) energy-storage performance has not been well established and no reports on the energy-storage feature of its high-temperature intermediate phase (IM) are available. In this work, high-quality PbHfO3 ceramics were prepared via the solid-state synthesis route. Based on high-temperature X-ray diffraction data, the IM of PbHfO3 was found to be orthorhombic, Imma space group, with antiparallel alignment of Pb2+ ions along the [001]cubic directions. The polarization–electric field (P–E) relation of PbHfO3 is displayed at RT as well as in the temperature range of the IM. A typical AFE loop revealed an optimal recoverable energy-storage density (Wrec) of 2.7 J/cm3, which is 286% higher than the reported data with an efficiency (η) of 65% at 235 kV/cm at RT. A relatively high Wrec value of 0.7 J/cm3 was found at 190 °C with an η of 89% at 65 kV/cm. These results demonstrate that PbHfO3 is a prototypical AFE from RT up to 200 °C, making it a suitable material for energy-storage applications in a wide temperature range.

Tetragonal tungsten bronze (TTB) based oxides constitute a large family of dielectric materials which are known to exhibit complex distortions producing incommensurately modulated superstructures as well as significant local deviations from their average symmetry. The local deviations produce diffuse scattering in diffraction experiments. The structure as well as the charge dynamics of these materials are anticipated to be sensitive to defects, such as cation or oxygen vacancies. In this work, in an effort to understand how the structural and charge dynamical properties respond to these two types of vacancy defects, we have performed measurements of dielectric susceptibilities and single crystal diffraction experiments of two types of TTB materials with both ‘filled’ (Ba2NdFeNb4O15 and Ba2PrFeNb4O15) and ‘unfilled’ (Sr0.5Ba0.5Nb2O6) cation sublattices. We also perform these measurements before and after oxygen annealing, which alters the oxygen vacancy concentrations. Surprisingly, we find that many of the diffuse scattering features that are present in the unfilled structure are also present in the filled structure, suggesting that the random fields and disorder that are characteristic of the unfilled structure are not responsible for many of the local structural features that are reflected in the diffuse scattering. Oxygen annealing clearly affected both color and dielectric properties, consistent with a diminishment of the oxygen vacancy concentration, but had little effect on observed diffuse patterns.

To investigate the treatment experience and information needs of patients with dentofacial deformities in the process of surgical program design, surgical treatment and postoperative rehabilitation.Thirty-six patients with dentofacial deformities at different treatment stages from March to July 2019 were selected for semi-structured interview. Colaizzi content analysis method and QSR NVivo 12.0 software were used to analyze and code the data, as well as extract the theme and genus.Three themes and eight categories were extracted, including① information needs in different treatment stages, mainly specific content of information needs at pre-operative preparation stage, orthognathic perioperative stage and post-operative rehabilitation stage; ② information support methods, i.e., diversified information support methods and patients' recognition of internet information;③ patients' cognition difference,namely the difference between patients' psychological expectation and the results of operation.Due to the treatment characteristics of orthognathic surgery and individual cognitive differences of patients, there is a large demand for information support at different stages of treatment. However, the current information support mode is limited, so it is necessary to further improve and provide scientific, professional and targeted information support for patients with dentofacial deformities.

The recent reports of superconductivity in Nd(1–x)Sr(x)NiO(2)/SrTiO(3) heterostructures have reinvigorated interest in potential superconductivity of low-oxidation state nickelates. Synthesis of Ni(1+)-containing compounds is notoriously difficult. In the current work, a combined sol-gel combustion and high-pressure annealing technique was employed to prepare polycrystalline perovskite Nd(1–x)Sr(x)NiO(3) (x = 0, 0.1, and 0.2). Metal nitrates and metal acetates were used as starting materials, and the latter were found to be superior to the former in terms of safety and reactivity. The Nd(1–x)Sr(x)NiO(3) compounds were subsequently reduced to Nd(1–x)Sr(x)NiO(2) using calcium hydride in a sealed, evacuated quartz tube. To understand the synthesis pathway, the evolution from NdNiO(3) to NdNiO(2) was monitored using in situ synchrotron x-ray diffraction during the reduction process. Electrical transport properties were consistent with an insulator-metal transition occurring between x = 0 and 0.1 for Nd(1–x)Sr(x)NiO(3). Superconductivity was not observed in our bulk samples of Nd(1–x)Sr(x)NiO(2). Neutron diffraction experiments at 3 and 300 K were performed on Nd(0.9)Sr(0.1)NiO(2), in which no magnetic Bragg reflections were observed, and the results of structural Rietveld refinement are provided.

Uniaxial tungsten bronzes have received increasing interest because of their potential application as lead-free ferroelectrics as well as their flexibility via chemical substitution. Here we demonstrate growth of single crystals of one such material, Ba2PrFeNb4O15, which possesses the tetragonal tungsten bronze structure, by the optical floating zone method. The challenge of this growth is to control the stability of the molten zone which allows the growth to persist for a long enough time to achieve large volume single crystals. Our work reveals that the use of a slight overpressure of air allows the molten zone to be maintained up to 7 h at a traveling speed of 4 mm/h. The obtained crystals were studied using high-resolution single crystal scattering, powder X-ray diffraction, and dielectric measurements. We find that Ba2PrFeNb4O15 possesses a rather complex average structure with a monoclinic symmetry in a P112/m space group and unit cell parameters of a = 12.49188(8) A, b = 12.49232(8) A, c = 3.92863(...

The recent reports of superconductivity in Nd1-x Sr x NiO2/SrTiO3 heterostructures have reinvigorated interest in potential superconductivity of low-oxidation state nickelates. Synthesis of Ni1+-containing compounds is notoriously difficult. In the current work, a combined sol-gel combustion and high-pressure annealing technique was employed to prepare polycrystalline perovskite Nd1-x Sr x NiO3 (x = 0, 0.1, and 0.2). Metal nitrates and metal acetates were used as starting materials, and the latter were found to be superior to the former in terms of safety and reactivity. The Nd1-x Sr x NiO3 compounds were subsequently reduced to Nd1-x Sr x NiO2 using calcium hydride in a sealed, evacuated quartz tube. To understand the synthesis pathway, the evolution from NdNiO3 to NdNiO2 was monitored using in situ synchrotron x-ray diffraction during the reduction process. Electrical transport properties were consistent with an insulator-metal transition occurring between x = 0 and 0.1 for Nd1-x Sr x NiO3. Superconductivity was not observed in our bulk samples of Nd1-x Sr x NiO2. Neutron diffraction experiments at 3 and 300 K were performed on Nd0.9Sr0.1NiO2, in which no magnetic Bragg reflections were observed, and the results of structural Rietveld refinement are provided.

LaNiO3&minus, &delta, single crystals have been obtained via high pressure floating zone growth under 149 bar of oxygen pressure. We find a radial gradient in the magnetic properties of specimens extracted from the as-grown boule, which we correlate with the appearance of ordered oxygen vacancy structures. This radial oxygen inhomogeneity has been characterized systematically using a combination of magnetization and X-ray scattering measurements. We establish the presence of rhombohedral ( R 3 &macr, c ), oxygen stoichiometric specimens at the periphery of the boule and the presence of a dilute concentration of ordered oxygen-deficient orthorhombic La2Ni2O5 in the center. Furthermore, we demonstrate that the as-grown, oxygen-deficient central regions of the crystal can be annealed under high oxygen pressure, without loss of crystallinity, into fully oxygenated LaNiO3, recovering magnetic properties that are characteristic of stoichiometric specimens from the exterior region of the crystal. Thus, single crystals of LaNiO3&minus, possess oxygen content that can be reversibly modified under oxidizing and reducing conditions.

The main purpose of this study was to explore the experience associated with patient's decision to have or not have orthognathic treatment.Phenomenological methodology was used in this study. Ten patients were collected from January 2018 to March 2018, who were consulted in the Department of Oral and Craniomaxillofacial Surgery, Center of Craniofacial Orthodontics in Shanghai Ninth People's Hospital. They were interviewed by semi-structured, face to face in-depth interviews. Data were organized and analyzed by Colaizzi methods.By reading, analysis and extraction, two topics, i.e, motivation and interference factor were obtained.The treatment information service was limited. Further research is needed to improve the information services that support the treatment decision of malocclusion patients and help them to make the best choice.

Ti-6Al-4V alloys with equiaxed, martensitic and lamellar microstructures, respectively, were shot peened. Microstructure observation, phase analysis and surface residual stress measurement were conducted to investigate the microstructure influence on shot peening effects. The experimental results indicate that after shot peening microstructure of surface layer became fine and homogeneous for the as-received alloy which showed equiaxial microstructure. Cracks were found in the surface layer for the sample with acicular martensitic microstructure. And the sample with coarse lamellar structure transformed to equiaxed microstructure in the surface layer. Surface residual stress showed obvious difference. The samples with equiaxed microstructure achieved a compressive residual stress of 660 MPa, the ones with acicular martensitic microstructure achieved 366 MPa, and the ones with coarse lamellar microstructure showed a residual stress only 125 MPa.

Single crystals of PrNiO3 were grown under an oxygen pressure of 295 bar using a unique high-pressure optical-image floating zone furnace. The crystals, with volume in excess of 1 mm3, were characterized structurally using single crystal and powder X-ray diffraction. Resistivity, specific heat, and magnetic susceptibility were measured, all of which evidenced an abrupt, first order metal-insulator transition (MIT) at ~130 K, in agreement with previous literature reports on polycrystalline specimens. Temperature-dependent single crystal diffraction was performed to investigate changes through the MIT. Our study demonstrates the opportunity space for high fugacity, reactive environments for single crystal growth specifically of perovskite nickelates but more generally to correlated electron oxides., Comment: 19 pages, 6 figures, Supporting Information included

Trilayer nickelates, which exhibit a high degree of orbital polarization combined with an electron count (d8.67) corresponding to overdoped cuprates, have been identified as a promising candidate platform for achieving high-Tc superconductivity. One such material, La4Ni3O8, undergoes a semiconductor-insulator transition at ~105 K, which was recently shown to arise from the formation of charge stripes. However, an outstanding issue has been the origin of an anomaly in the magnetic susceptibility at the transition and whether it signifies formation of spin stripes akin to single layer nickelates. Here we report single crystal neutron diffraction measurements (both polarized and unpolarized) that establish that the ground state is indeed magnetic. The ordering is modeled as antiferromagnetic spin stripes that are commensurate with the charge stripes, the magnetic ordering occurring in individual trilayers that are essentially uncorrelated along the crystallographic c-axis. Comparison of the charge and spin stripe order parameters reveals that, in contrast to single-layer nickelates such as La2-xSrxNiO4 as well as related quasi-2D oxides including manganites, cobaltates, and cuprates, these orders uniquely appear simultaneously, thus demonstrating a stronger coupling between spin and charge than in these related low-dimensional correlated oxides., Comment: 34 pages, 10 figures (including SI). Accepted by Physical Review Letters

The origins of the metal-insulator and magnetic transitions exhibited by perovskite rare-earth nickelates, R${\mathrm{NiO}}_{3}$ (where $R$ is a rare-earth element), remain open issues, with charge disproportionation, magnetic interactions, and lattice response across multiple length scales being among the many possible origins. Recently, growth of single crystals of ${\mathrm{LaNiO}}_{3}$, which is the only member of these compounds that remains metallic in its ground state, has been reported, opening a new chapter in the investigation of the perovskite nickelates. Here, using a combination of magnetometry, heat capacity, and neutron scattering on as-grown and purposely reduced $\mathrm{LaNi}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ crystals, we show that both antiferromagnetic and ferromagnetic phases with a N\'eel temperature of \ensuremath{\sim}152 K and a Curie temperature of \ensuremath{\sim}225 K can be induced by reduction of the oxygen content. Transmission electron microscopy shows that these phases are characterized by ordered oxygen vacancy defect structures that exist as dilute secondary phases in as-grown crystals despite growth in partial oxygen pressures up to at least 130 bar. The demonstration of antiferromagnetism resulting from oxygen vacancy ordered structures implies that stoichiometry must be explicitly considered when interpreting the bulk properties of $\mathrm{LaNi}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ single crystals; accordingly, the implications of our results for putative oxygen-stoichiometric ${\mathrm{LaNiO}}_{3}$ are discussed.

According to the previous results from transcriptome analysis of Ligustrum quihoui, a glycosyltransferase gene(xynzUGT) was cloned by rapid amplification of cDNA ends(RACE). The full length cDNA of xynzUGT was 1 598 bp, consisting of 66 bp 5'-UTR, 1 440 bp ORF and 92 bp 3'-UTR. The ORF encoded a 480 amino-acid protein(xynzUGT) with a molecular weight of 54 826.67 Da and isoelectric point of 5.82. The structure of enzyme was analyzed by using bioinformatics method, the results showed that the primary structure contained a highly conserved PSPG box of glycosyltransferase, the secondary structure included α helix(38%)

Dioecious plant species represent an major component of terrestrial ecosystems. Little is known about sex-specific responses to soil salinity. Populus cathayana Rehd, which is a dioecious, deciduous tree, was employed as a test species in our study. In a semi-controlled environment, physiological responses to salinity were investigated in male and female P. cathayana cuttings, which were subjected to two salt regimes: 0 and 80 mM NaCl added to the Hoagland’s solution for one month growth. Relative to the control, the saline treatment significantly decreased net photosynthetic rate ( P n ), transpiration ( E ), stomatal conductance ( g s ), carotenoids (Caro), chlorophyll a (Chl a ), total chlorophyll (TC) and catalase (CAT) activity, but increased Na + , Ca 2+ , K + , malondialdehyde (MDA) content, superoxide dismutase (SOD) activity and carbon isotope composition ( δ 13 C) in both sexes. Different sensitivity to saline conditions between males and females was detected. With higher soil salinity, females exhibited lower P n , Chl a , TC, Chl a / b , Ca 2+ , Ca 2+ /Na + , K + /Na + , SOD and CAT activities but higher Na + and MDA content than males. However, there were no significant differences in these traits (except for SOD and CAT activities) detected in the control group. Our results indicated that males may be more tolerate to salinity than females, with females having lower gas exchanges, chlorophyll pigments, antioxidant enzyme activities, K + /Na + ratio and water use efficiency (WUE) than males.

A series of multi-walled carbon nanotubes/polyurethane (MWNTs/PU) composite conducting dispersoids were prepared via an in situ coupling reaction among linear hydroxyl-terminated polymer diols, 1,6-hexamethylene diisocyanate (HDI) and various chain extenders. The composite conducting thin films were formed by spin-coating and depositing the dispersoids onto comb-like electrode substrates. The resulting structure and the dispersion quality of MWNTs in the dispersoids were examined by means of FTIR, XRD, TEM, SEM and UV–vis analyses. The response of the as-prepared films toward some volatile organic solvent vapors such as benzene, anhydrous ether, acetone and chloroform was evaluated. The experimental results indicated that the composite conducting films constructed by hydroxyl-terminated poly(butadiene-co-acrylonitrile), trimethylolpropane, and MWNTs–OH bear better vapor responsiveness. The dispersion behavior of MWNTs in the dispersoids, types of MWNTs and soft–hard segmental compositions are believed to be closely related with the sensing properties of the films. In particular, the chemical linkage of MWNT–OH with HDI in the PU matrix is expected to improve the dispersivity and further to enhance the sensing properties of the composite sensors. The vapor sensing properties well reveal that these materials have a possibility as a candidate of volatile organic solvent vapor sensors.

The electrowinning method for treating high copper cyanide solution was investigated by thermodynamics analysis and experiment. The influences of copper concentration, solution temperature, electrolysis time, current density and flow rate on copper recovery and current efficiency was studied in detail and the suitable operation parameters were chosen. Copper electrowinning from the industrial barren solution with copper concentration of 12.40g/L was performed under the condition of current density of 75 mA/cm2, flow rate of 30mL/min and 50°C for 8 hours. An alloy with copper concentration of 99.87% was obtained at the cathode with total energy consumption 2938KWh/t. The used electrolysis solution added with some fresh cyanide sodium solution can be recycled to leaching process.

This paper studied the sex-specific differences of male and female Populus cathayana seedlings in their ecophysiological characteristics and photosynthesis under the stress of aluminum (216 mg Al(3+) x kg(-1)). Under the effects of aluminum, the malonaldehyde (MDA) and soluble protein (Pr) contents of the male and female seedlings increased significantly (P0.001), and the males had a significantly lower MDA content and a significantly higher Pr content than the females. The peroxidase (POD) activity of the males increased but the superoxide dismutase (SOD) activity decreased significantly, while the POD and SOD activities of the females had no significant variation. The net photosynthetic rate (Pn) of both male and female seedlings decreased significantly (P = 0.001), and the transpiration rate (Tr) of the female seedlings decreased (P = 0.007) and the instant water use efficiency (WUEi) increased significantly, while no significant variations were observed in the Tr and WUEi of the male seedlings. The total chlorophyll and chlorophyll a contents and chlorophyll a/b ratio of the females decreased significantly, resulting in a significantly higher chlorophyll a/b ratio of the males. The specific leaf area (SLA) of the females decreased but that of the males increased significantly. No significant variation was observed on the leaf- and stem dry mass. Comparing with the females, the males had higher Pr and chlorophyll contents and higher active antioxidant enzymes activity to maintain higher Pn, and thus, had greater resistance against aluminum stress.