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Quantum computation attaches importance to high-precision quantum manipulation, where the quantum state transfer with high fidelity is necessary. Here, we propose a new scheme to implement the quantum state transfer of high fidelity and long distance, by adding on-site potential into the qubit chain and enlarging the proportion of the coupling strength between the two ends and the chain. In the numerical simulation, without decoherence, the transfer fidelities of 9 and 11 qubit chain are 0.999 and 0.997, respectively. Moreover, we give a detailed physical realization scheme of the quantum state transfer in superconducting circuits, and discuss the tolerance of our proposal against decoherence. Therefore, our scheme will shed light on quantum computation with long chain and high-fidelity quantum state transfer. [ABSTRACT FROM AUTHOR]

In order to solve the scheduling and path planning problems of multi-AGVs in an intelligent manufacturing workshop, it is necessary to consider loading, unloading, and transporting the workpiece of each AGV at the same time. A step task scheduling and path optimization mode of AGV is proposed. The process is as follows: Firstly, a mathematical model algorithm and a material transportation task allocation algorithm based on the urgency degree of workpiece processing were established for the optimization objective, and all workpiece transportation task sequences between shelves and processing equipment were assigned to the corresponding AGV to generate the initial feasible path of each AGV. Then, the AGV collision detection and anti-collision algorithm are designed to plan the global collision-free walking path of multi-AGVs in the workshop, and the path can be dynamically adjusted according to the delivery task. The model is solved by a heuristic algorithm ant colony algorithm and MATLAB coding. Finally, an example is given to verify the effectiveness of the method, which can effectively solve the task allocation of multi-AGVs and avoid collision path planning based on the transportation task sequence, and improve the work efficiency of AGV. This research can provide a theoretical basis and practical reference for realizing multi AGVs collaborative scheduling by using AGV automated material transport system in an intelligent production workshop. [ABSTRACT FROM AUTHOR]

Hybrid improper ferroelectricity, which is induced by the coupling of oxygen octahedral rotation and tilt in oxide materials, has great potential to create single-phase multiferroic materials with intrinsic electric field-controlled magnetism. Based on previous experiments with bi-layered Ruddlesden-Popper Sr-based materials, hybrid improper ferroelectricity in Sr3Hf2O7 was investigated by first-principle calculations in the present work. The results show that the ferroelectric A21am phase has the lowest energy among all possible phases, indicating that it is the ground state. The spontaneous polarization calculated by the Berry phase approach and Born effective charge model is approximately 4.6 μC/cm2, in agreement with those reported for other Sr-based compounds. Compared to Ca3Ti2O7, the smaller polarization of Sr3Hf2O7 is attributed to the negative contribution of the HfO2 layer to global polarization. The possible ferroelectric switching path was determined using the nudged elastic band method. The energy barriers of the two four-step paths across the non-polar Pbnm and Pnab phases are almost the same, and they are the lowest energies among all possible paths. Competition between these paths can help us understand complex phase transitions in analogous compounds. In summary, hybrid improper ferroelectricity was predicted in Sr3Hf2O7 for the first time, and the possible ferroelectric switching paths were determined. [ABSTRACT FROM AUTHOR]

Hybrid improper ferroelectricity is induced by the coupling of oxygen octahedral rotation and tilt, and it may provide a promising way to develop new room-temperature single-phase multiferroic materials with a strong magnetoelectric effect. Though ferroelectric polarizations are confirmed by the electric hysteresis loops at room temperature, the ferroelectric-paraelectric phase transition has not been well understood. In the present work, the crystal structures, dielectric properties, and phase transition behaviors of Ruddlesden-Popper Sr3–xCaxSn2O7 ceramics are thoroughly determined. Ferroelectricity is confirmed through the polarization-electric field hysteresis loops at room temperature, and the Curie temperature is identified by the variable-temperature differential scanning calorimetric analysis and dielectric characterization. The polarizations and Curie temperatures of the present ceramics increase with increasing the calcium content. An improper ferroelectric transition is experimentally evidenced by a small dielectric constant and a step variation of dielectric constant around the Curie temperature, and the thermal hysteresis of dielectric constant confirms the first order transition nature. Moreover, the fitting result of Landau phase transition theory also suggests the first-order improper ferroelectric transition nature. The variable-temperature Raman result implies a tetragonal paraelectric phase above TC. The present work confidently confirms the first-order hybrid improper ferroelectric transitions in the present ceramics, and ferroelectric properties can be readily tuned by substituting the cations at the A-site. [ABSTRACT FROM AUTHOR]

Hybrid improper ferroelectricity (HIF) has been proposed as a candidate approach to create room- temperature multiferroic materials with an intrinsic electric-field controlled magnetism effect, and HIFs in bi-layered Ruddlesden-Popper Ca3-xSrxTi2O7 ceramics have been confirmed in the present work. The ferroelectric hysteresis loops are observed in these ceramics at room temperature, and the polar orthorhombic structures with oxygen octahedral rotation and tilt modes have been confirmed by room-temperature X-ray powder diffraction. The amplitudes of oxygen octahedral rotation and tilt modes decrease with the increasing x value, which in turn leads to the decrease of remnant polarization in these ceramics. A first-order phase transition has been evidenced by the differential scanning calorimetry measurement, and the temperature of phase transition decreases linearly with the increasing content of strontium cations. It is found that the amplitude of oxygen octahedral distortion is the dominating factor that affects ferroelectric polarization in partial-ordered bi-layered Ca3Ti2O7-based ceramics. [ABSTRACT FROM AUTHOR]

The microstructure, corrosion behavior, and electrochemical behavior of as-cast Mg-4Y-xZn (x=1,2,3,4 wt.%) are studied by SEM, weight loss and electrochemical tests. Mg12YZn (X), Mg3Y2Zn3 (W) and Mg24Y5 constitute the phase composition system of the alloy. When Zn content is 1 wt.%, all tests reveal that alloy has the optimal corrosion performance. The second phase in these alloys, due to their nobler nature than α-Mg, exists as a cathode during the corrosion process, so that α-Mg preferentially occurs corrosion to accelerate the formation of corrosion pits. After soaking in 3.5 wt.% NaCl solution for some time, the stability of the W phase changed, and gradually dissolved, which was finally removed by chromic acid used for removal of corrosion products. In addition, X phase can be used as an anode in the micro-galvanic cells formed with W phase to reduce the corrosion rate of α-Mg and thus improve the corrosion performance of the alloy. [ABSTRACT FROM AUTHOR]

In the present work, the structure, magnetic, and dielectric characteristics of Nd2NiMnO6 and Sm2NiMnO6 have been investigated with comparison to those for La2NiMnO6. The magnetic and dielectric properties of the present ceramics vary with decreasing lanthanide ionic radius (RLn). Both Nd2NiMnO6 and Sm2NiMnO6 are ferromagnetism with the monoclinic symmetry (space group P21/n). The Curie temperature TC of Nd2NiMnO6 and Sm2NiMnO6 is 194 K and 156 K, respectively, and it decreases with decreasing bond angle which depends on RLn. Meanwhile, the dielectric constant [variant_greek_epsilon]′ monotonically decreases with decreasing RLn. The similar variation tendency of magnetic and dielectric characteristics with RLn indicates that the structural origins for the magnetic and dielectric response should be closely linked with each other. [ABSTRACT FROM AUTHOR]

In the present work, the effects of Ti-substitution for Mn upon the structure, magnetic and dielectric properties in La2NiMnO6 ceramics have been investigated. Ti-substitution for Mn strongly affects the crystallographic, magnetic, and dielectric properties of La2NiMnO6 double perovskite ceramics. Refinements of the x-ray diffraction data show that all compositions investigated here have the monoclinic perovskite structure in space group P21/n with a partially ordered arrangement of Ni and Mn/Ti cations. The magnetic nature of the present ceramics with x up to 0.8 is ferromagnetic (FM), while that is antiferromagnetic for La2NiTiO6. The Curie temperature and the spontaneous magnetization, or FM component, decrease with increasing x. These ferromagnetic states are attributed to the Ni2+-O-Mn4+ superexchange interaction. The dielectric constant monotonically decreases and the relaxor-like behavior is suppressed with x. The similar variation tendency of magnetic and dielectric properties with increasing x can be explained simply by the dilution effect. [ABSTRACT FROM AUTHOR]

Ca[(Mg1/3Ta2/3)1-xTix]O3 (hereafter denoted as CMTT) and (Ca1-0.39xNd0.26x) [(Mg1/3Nb2/3)1-xTix]O3 (hereafter denoted as CNMNT) complex perovskite ceramics were studied by Raman spectroscopy combined with Rietveld analysis. The crystal structures changed from monoclinic structure with P21/c space group to orthorhombic structure with Pbnm space group for both systems. The main structure of the two systems was orthorhombic and the characteristic modes for the orthorhombic structure with space group Pbnm could be found in all the compositions. Raman modes at around 408 cm-1 could only be found for compositions with 1:2 long range cation ordering while modes at around 800 cm-1 could be found for all the compositions in both systems. They were concluded to be correlated with the 1:2 long range cation ordering and different short range cation ordering, respectively. Two Ag modes at around 800 cm-1 represented for 1:2 and 1:1 short range cation ordering were observed for CMTT ceramics with x=0.1–0.6 while only 1:2 short range Ag mode was observed in all compositions for CNMNT ceramics. The weak A-O hybridization was considered to be the reason for the absence of the 1:1 short range cation ordering. The short range cation ordering was suggested to be appreciably beneficial to the Qf value. [ABSTRACT FROM AUTHOR]

A randomly disordered quantum wire superlattice (d-QWR-SL) structure was fabricated by means of metalorganic vapor phase epitaxy. Photoluminescence (PL) and the carrier lifetime properties were investigated systematically. The PL intensity was found to be independent of temperatures below 170 K. This thermally stable feature was due to dramatic suppression of the nonradiative recombination in the wire region. The carrier lifetime measurement confirmed the high thermal PL stability in the d-QWR-SL structure. This high thermal PL stability may be due to the state localization in the d-QWR-SL structures. [ABSTRACT FROM AUTHOR]

Excess minority carriers create boron-related recombination centers that degrade the efficiency of the non-particle-irradiated silicon solar cells. However, the carrier-induced reactions among the radiation-induced defects are poorly understood for devices exposed to particle radiation. This study investigates the structure, electronic properties, formation and annihilation mechanisms, and diffusion dynamics of the carrier-induced defects in particle-irradiated boron-doped silicon using density-functional modeling and junction spectroscopy. By revisiting the ground-state structures of the boron-di-interstitial clusters (B I 2), we find that the calculated acceptor and donor levels of such defects agree well quantitatively with the carrier-induced deep-level transient spectroscopy (DLTS) hole emission signatures at 0.43 and 0.53 eV above the valence band edge (E v), respectively. We also find that the formation of B I 2 is thermally activated by an energy of 0.50 eV, which we explain theoretically by the reduction of the migration barrier of mono-interstitials to 0.53 eV in the presence of excess minority carriers. Moreover, we discover that the B I 2 are potentially mobile with a migration barrier of 1.18 eV, contrary to the present understanding. [ABSTRACT FROM AUTHOR]

Hybrid improper ferroelectricity is induced by the coupling of oxygen octahedral rotation and tilting, and a promising way to create multiferroic materials with a strong magnetoelectric effect can be proposed. Although some hybrid improper ferroelectric materials with Ruddlesden-Popper structures have been discovered experimentally, the small polarizations and high coercive fields will severely limit their practical applications. To deal with this issue, an alternative way is proposed by the first-principles calculations in the present work. By calculating the energies of phases with oxygen octahedral rotation and tilting in Ca3TiMO7 (M = Si, Ge, Mn, Sn, Hf, and Zr) compounds with five B-site ordering configurations, it is found that the tolerance factor has a considerable impact on their ferroelectric properties. The energy barriers and ferroelectric polarizations increase with decreasing tolerance factor. Moreover, the individual-layer contributions to the total polarizations depend on the space group, which is also decided by the tolerance factor of the compound. Therefore, to enhance the ferroelectric polarization in B-site substituted Ca3Ti2O7, the tolerance factor should be decreased according to the calculation results of this work. [ABSTRACT FROM AUTHOR]

Transient band-gap renormalization (BGR) effects are investigated in AlGaAs/GaAs V-grooved quantum structures. The temperature-dependent transient BGR effects in the sidewall quantum well (SQWL) provide direct evidence of the existence of the blocking effect by the necking region barrier on the carrier trapping process. These effects provide a useful method to show the existence of the necking region, particularly for very thin SQWL structures. The temperature-dependent lifetimes of the SQWL and quantum wire (QWR) provide further proof of the carrier trapping process from the SQWL to the QWR. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A zirconium- and Cr(III)-containing conversion coating on Al alloy 2024-T3 was prepared in solution containing Cr2(SO4)3 and K2ZrF6. Its composition was analyzed by energy dispersive X-ray spectrometry (EDS), and its corrosion resistance was investigated using polarization curve, electrochemical impedance spectroscopy (EIS), and salt spray exposure. An artificial scratch cell was used to investigate its 'self-repairing' effect by EIS and X-ray photoelectron spectroscopy (XPS). In addition to Al, the conversion coating contained Zr, Cr, O, and F. The conversion coating provided obvious corrosion protection for the Al alloy 2024-T3. The EIS measurement and corrosion morphology observation of bare samples (i.e., uncoated samples) in the artificial scratch cell confirmed that the conversion coating possessed 'self-repairing' effect. XPS analysis showed that Cr(III) species, but not Zr species were transported from the conversion coating to the nearby bare area as in a scratch. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this study is to explore the corrosion behaviors of tube pile steel with the addition of 0.2 per cent Cu and 0.2 per cent Cu-0.2 per cent Cr in half-immersion environment.Design/methodology/approach The electrochemical corrosion behaviors of tube pile steel with different alloy-elements addition were identified using the polarization curve method and electrochemical impedance spectroscopy technique. Corrosion product and its morphology were analyzed by X-ray diffraction, optical microscope and scanning electron microscopy.Findings Results indicate that the most serious corrosion occurred in the liquid-air interface zone due to the higher oxygen and water concentration. With the addition of Cu and Cu-Cr, pits were getting smaller and denser, transforming the corrosion type from pitting corrosion to uniform corrosion gradually. Rust layer containing Cu/Cr tended to compact and inhibited the anodic process, while the enrichment of Cu/Cr in rust layer decelerated the dissolution of substrate, thus the expanding of pits was suppressed.Originality/value This paper studied the corrosion behaviors of liquid-air interface zone of tube pile steel and verified the transformation of corrosion type with adding Cu, Cu/Cr elements. [ABSTRACT FROM AUTHOR]

The hybrid improper ferroelectricity (HIF) has been proposed as a promising way to create multiferroic materials with strong magnetoelectric coupling by the first-principle calculation, and the experimental evidences of HIF in Ruddlesden-Poper Ca3(Ti1-xMnx)2O7 (x=0, 0.05, 0.1, and 0.15) ceramics have been shown in the present work. The room temperature ferroelectric hysteresis loops are observed in these ceramics, and a polar orthorhombic structure with two oxygen tilting modes has been confirmed by the X-ray powder diffraction. A first-order phase transition around 1100K in Ca3Ti2O7 was evidenced, and the temperatures of phase transitions decrease linearly with increasing of the contents of Mn4+ ions. Based on the result of first-principle calculations, the polarization should be reversed by switching through the mediated Amam phase in Ca3Ti2O7 ceramics. [ABSTRACT FROM AUTHOR]

This article proposes a thermal fatigue life prediction model for particle reinforced composites. First, a three-phase model was used to determine the effective eigen strain of a two-phase element formed by an ellipsoidal matrix shell surrounding an ellipsoidal particle, and then the disturbance strain in the two-phase element caused by thermal inconsistency was obtained. If the average stress in the effective medium was considered as vanished, the thermal stress field in the matrix and particles was obtained by considering random orientation of two-phase elements. Second, based on the interface cracks propagating around the ellipsoidal particles, the strain energy release rate was examined. When the strain energy release rate reached the critical value of the matrix, the debonding stress was determined. The subtending angle and initiation crack length were available. Finally, according to the low cycle fatigue crack growth rate formation, the thermal fatigue life was computed. The results show that the bigger the thermal stress is, the smaller the thermal fatigue life is, indicating that thermal fatigue life is an exponential function of crack initiation length and critical length. [ABSTRACT FROM AUTHOR]

Electroplated nickel was chemically modified using an aminosilane coupling agent (as an alternative to chromate) in order to improve its corrosion performance. Infrared spectroscopy revealed that the silane bonded to the metal satisfactorily. The corrosion behaviour of a nickel electroplated steel workpiece was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy to optimise the silane deposition conditions. These data confirm that the most effective conditions are dipping in the silane coupling agent solution for 30 s and then curing at 100°C for 40 min. [ABSTRACT FROM AUTHOR]

Over the past few decades, fish resources have declined severely owing to the river-lake disconnection within the Yangtze River floodplain. Studies on fish migrations between rivers and floodplain waters are imperative for fish resources restoration and lake management. However, few studies have as yet documented the migration rhythms of river-lake migratory fishes. Monthly investigations of the fish assemblage structure were conducted in three regions of the Dongting Lake, which is connected to the Yangtze River. Main results were: (i) Fish catches varied greatly, depending on the water level and area of the lake; (ii) Ten river-lake migratoty species were caught during the study, 80% of these during July-October when the water level was high. Species richness and relative abundance both decreased with increasing distance from the river, and the timing of peak abundance occurred later in the year; (iii) Abundance of grass carp ( Ctenopharyngodon idella) and silver carp ( Hypophthalmichthys molitrix) peaked in July and August and were mainly composed of 0 + fishes. The results revealed that the key time for migration into the lake is July-August. Combining the results from previous studies, a comprehensive view is given of migration patterns of four domestic Chinese carps; (iv) Brass gudgeon ( Coreius heterodon), appeared to migrate into the Dongting Lake as two separate shoals, differentiated by body size. They also appeared to remain close to the lake mouth area. Based on the above results, two recommendations can be made for river-lake migratory fish conservation in the Yangtze floodplain: prolonging the current fishing ban period of April-June to April-September; and opening sluice gates for as long as possible during April-September in order to maximize the opportunities for fish migration. [ABSTRACT FROM AUTHOR]

Drilling fluid with the high density has been successfully used in many kinds of special formations such as gypsum salt bed, salt aquifer, or compound salt formation. Some problems with this kind of the fluid, however, still have to be considered, for example the high temperature resistance in some complicated deep wells, rheological properties control, and the influence of solid content to rheological properties. The authors introduce, based on the research about some important elements such as rheological properties and the quality of sedimentation stability, a drilling fluid with the high density of 2.45 g/cm³ that has good rheological properties, excellent qualities of sedimentation stability, low water loss, well antisloughing, and small lubrication coefficient, and which can be perfectly used in the deep slim-hole well with the high pressure salt aquifer. In addition, this drilling fluid system with the density of 2.45 g/cm³,no matter in the laboratory test or in the field case (No. 3 well of Jeddah), both performs excellently and controls well the salt crystallization, reducing the rate of the crystallization and preventing sticking, jets blocking, or torque increasing. Finally, with the successful application, this drilling fluid can be regarded as a good example for other deep wells or ultradeep wells with the complicated formation in Fergana Valley, Uzbekistan. [ABSTRACT FROM AUTHOR]

Using animal mammary glands as bioreactors for producing commercially important proteins is a cutting-edge direction in the field of biotechnology development and application. Dairy goats are an important dairy livestock, with roughage-resistance, fast propagation, long lactation periods and high milk production per bodyweight; these characteristics make dairy goats ideal for use as mammary gland bioreactors. Foot-and-mouth disease virus 2A (FMDV 2A) is an efficient viral cleavage element that mediates proteolytic cleavage independent of the presence of other FMDV sequences. It is often incorporated into recombinant vectors to generate cleavage in the presence of heterologous sequences. To achieve specific co-expression of two heterologous genes in goat mammary gland epithelial (GMGE) cells, a mammary gland-specific bicistronic expression vector, pFIEβ, containing the β-casein 5' flanking sequence and FMDV 2A, was successfully constructed and the specific expression of human interleukin 2 (hIL-2) and enhanced green fluorescent protein (EGFP) was conducted in primary GMGE cells. Another bicistronic expression vector, pFIEC, driven by the cytomegalovirus promoter, was constructed as a positive control. In cells transfected with pFIEβ and pFIEC, RT-PCR verified the existence of recombinant fusion mRNA of hIL-2 upstream of EGFP within the FMDV 2A cassette fragment and western blot analysis showed the existence of the fusion between hIL-2 and EGFP. It is concluded that FMDV 2A generated specific co-expression of multiple genes for the first time in primary GMGE cells driven by the β-casein promoter. The efficient production of mammary gland bioreactor is a cutting-edge direction in the field of biotechnology development and application. To achieve co-expression of two heterologous genes in goat mammary gland epithelial cells, a mammary gland-specific bicistronic expression vector mediated by FMDV 2A was constructed and successfully expressed. It suggested the feasibility of multiple gene expression in transgenic dairy goats, which will increase the production ability of mammary gland bioreactor for commercially important proteins. [ABSTRACT FROM AUTHOR]

Phase-change memory (PCM) materials, such as chalcogenide alloys, have the ability for fast and reversible transition between their amorphous and crystalline states. Owing to the large optical/electrical contrast of the two states, PCM materials have been developed for data storage. It has been generally accepted that thermal effects, caused by laser irradiation or electrical pulses, control the amorphization by melting the sample and subsequent quenching, while crystallization is realized by thermal annealing. An important element that has not been considered extensively, however, is the role of electronic excitation by optical or electrical pulse. Strictly speaking, until electrons and holes recombine, the system under external stimulus is in a non-equilibrium environment, especially when the excitation intensity is high. This raises an important question: can the excitation alone induce phase transition for PCM data storage without the usual thermal melting? Here, we will review the recent experimental and theoretical indications and evidence in support of the electronic excitation-induced phase change in PCM materials and discuss potential ramifications of the athermal phase-change phenomenon for data storage. [ABSTRACT FROM AUTHOR]

Traditional Lorch-window technique was modified to the truncated Lorch-window through various truncation ranges to apply the Lorch-window functions. The terminal ripples in radial distribution functions (RDFs) were weakened and the shoulder peak at 2.6 Å in crystalline Ge2Sb2Te5 (GST) was revealed by the indication of the off-octahedral Ge. The Cs-corrected high resolution transmission electron microscopy image and the corresponding simulations suggest that the off-octahedral Ge atoms are indeed in the tetrahedral symmetry. These results indicate that the complex structural details in the intermediate phase of GST other than simple rock-salt structure though the quantified information, such as the accurate atomic positions of the off-octahedral Ge need being further clarified in the future. These results also reveal the significance of high-Q signals in revealing the structures in short range order. Left (a): Original reduced interference function F( Q) (black) and truncated F( Q) data. Right (b): Corresponding RDF curves. L-12 (red half-solid triangle) represent the data with a truncation range of 12 Å−1, and L-16 (open square) for the truncation range of 16 Å−1. [ABSTRACT FROM AUTHOR]

In this paper a bio-based epoxy with outstanding thermal and mechanical properties was synthesized using a rosin-based epoxy monomer and a rosin-based curing agent. The chemical structures of rosin based epoxy monomer and curing agent were confirmed by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FT-IR) spectra. The flexural mechanical and dynamic mechanical properties as well as thermal stability of the cured epoxy were investigated. The results showed that the cured epoxy exhibited a glass transition temperature (Tg) of 164°C and its flexural strength and modulus were as high as 70 and 2200 MPa, respectively. This indicated that a wholly bio-based epoxy resin possessing high performance was successfully obtained. [ABSTRACT FROM AUTHOR]

new composite for water treatment was prepared by melt blend for oil and hexavalent chromium absorption. Ethylene Propylene Diene Monomer (EPDM) was the matrix, calcinatory FeO and anion-exchange resin 201×7 were the fillers. This composite can suspend in water-oil contact (WOC) and absorb oils and hexavalent chromium in wastewater simultaneously. The absorbencies of composites changed greatly with various ratios of calcinatory FeO and anion-exchange resin 201×7. The results showed that the oil absorbencies increased continuously and hexavalent chromium absorbencies were step-down as calcinatory FeO loadings from 13 to 19%. The composite can adsorb oils and hexavalent chromium simultaneously. The optimized proportion of calcinatory FeO and anion-exchange resin 201×7 in composite was found when the absorbencies of oils and hexavalent chromium reaching the maximum simultaneously. This composite is an inexpensive, convenient and high efficiency material for removing oils and hexavalent chromium from wastewater. [ABSTRACT FROM AUTHOR]

The crystalline structure and dielectric properties of nominal Sm1.75Sr0.25NiO4 ceramics are presented. Three phases, Sm1.70Sr0.30NiO4, Sm2O3 and NiO, are found in the present ceramics, and the abundances are 77.7(1.1) wt%, 19.2(3) wt% and 6.1(2) wt%, respectively. The temperature-stable giant dielectric constant over 60 000 even up to 5 MHz is observed in a broad temperature range. The modulus plots show that the giant dielectric constant should be originated from the contribution of the grain interior instead of grain boundary. Compared with the other giant dielectric constant materials, the present materials have the great potentiality in the practical application, especially for the high frequency application. [ABSTRACT FROM AUTHOR]

Dense (1− x)Ca(Mg1/3Ta2/3)O3/ xCaTiO3 ceramics (0.1≤ x≤0.9) were prepared by a solid-state reaction process. The crystal structures and microstructures were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Single-phase solid solutions were obtained in the entire composition range. Long-range 1:2 ordering of B-site cations and oxygen octahedra tilting lead to the monoclinic symmetry with space group P21/ c for x=0.1. For x above 0.1, the long-range ordering was destroyed and the crystal structure became the orthorhombic with space group Pbnm. The microwave dielectric properties showed a strong dependence on the composition and microstructure. The dielectric constant and temperature coefficient of resonant frequency increased nonlinearly as the CaTiO3 content increased while the Qf values decreased approximately linearly. Good combination of microwave dielectric properties was obtained at x=0.45, where ℇr=45.1, Qf=34 800 GHz, and τf=17.4 ppm/°C. [ABSTRACT FROM AUTHOR]

Two patients presenting with subcutaneous nodules, plaques, papules and ulceration caused by Trichophyton rubrum are described in this report. The first case was a 46-year-old woman referred with erythema and desquamation over her trunk, hands and feet for 30 years, progressing to nodules and ulceration over her trunk, arms and scalp for the last 2 years. The second case was a 34-year-old man who presented with a 2-year-history of itchy, erythema and desquamation over the trunk, progressing to papules, nodules and cyst around his ear, on the neck and scalp for 1 year. The diagnoses were suspected after direct microscopical examinations of the discharge materials, which revealed the presence of hyaline hyphae. The histological examinations showed granulomatous inflammatory infiltrates with fungal elements in the dermis including epithelioid cells, giant cells, lymphocytes and eosinophils, and the periodic acid-Schiff stain showed hypha within the granulomas. Cultures of puncture materials, skin biopsies and nails confirmed the diagnosis identifying T. rubrum. Antifungal therapies with itraconazole were successful in both patients, the lesions were completely clear with atrophic scars after 3 months. Side effects were not noticed during the medication. We discuss the clinical types of granulomatous cutaneous lesions caused by dermatophyte infections and evaluate the therapeutic effect of itraconazole. [ABSTRACT FROM AUTHOR]

Population-based association studies are powerful tools for the genetic mapping of complex diseases. However, this method is sensitive to potential confounding by population structure. While statistical methods that use genetic markers to detect and control for population structure have been the focus of current literature, the utility of self-defined race/ethnicity in controlling for population structure has been controversial. In this study of 1334 individuals, who self-identified as either African American, European American or Hispanic, we demonstrated that when the true underlying genetic structure and the self-defined racial/ethnic groups were roughly in agreement with each other, the self-defined race/ethnicity information was useful in the control of population structure. [ABSTRACT FROM AUTHOR]

Microstructures and electrical properties of low dielectric constant (low-k) nanoporous silica films, prepared by sol–gel method using hydrofluoric acid (HF) replacing hydrochloric acid (HCl) as catalyst, have been investigated. It is found that the incorporation of HF effectively adjusts the hydrolysis and condensation of the tetraethoxylane based silica sols and makes the surface modification more sufficiently, leading to the increase of the porosity and the change in chemical bonds, and thus significantly improves the electrical properties of the films. The k value of 1.5 is reached in HF catalyzed films, which is much lower than that in HCl ones. The leakage current density are reduced to the lowest value of 6.12×10-9 A/cm2 in HF catalyzed films. It is determined that the Schottky emission occurs in HF catalyzed films, and both Schottky and Poole–Frenkel emissions occur in HCl ones, which may be due to the lower effective oxide charge density near the nanoporous silica and Si interfaces in HF catalyzed films than in HCl ones. [ABSTRACT FROM AUTHOR]

Numerical discretization schemes are developed to approximate functionals of stochastic differential equations with jumps, and the convergence is shown to have an appropriate order. For the Euler scheme and the second order weak scheme, the leading coefficient of their global errors are determined by the stochastic Taylor expansion. Based on the error expression, the extrapolation technique can be applied to get a higher order convergence. Numerical examples are provided to compare various weak schemes and extrapolations. Key words: jump diffusion; Itô­Taylor expansion; weak convergence; extrapolation method [ABSTRACT FROM AUTHOR]

We review a number of methods that have recently been proposed to decompose changes in industrial energy consumption. We then propose two parametric methods based on the Divisia index, where the integral path problem in the Divisia index is transformed into a parameter estimation problem. It is shown that there can be an infinite number of sets of decomposition results, each corresponding to a particular combination of parameter values, and that several recently proposed methods are in fact special cases of these two methods. We then introduce an approach to estimate the parameter values uniquely. Referred to as the Adaptive Weighting Divisia Method, this method is supported by vigorous mathematical analysis and does not involve arbitrary guesses of parameter values as is the case for the existing methods. We also discuss the application and the associated statistical problems of the various decomposition methods, and present the results of a study using the data for Singapore industry. [ABSTRACT FROM AUTHOR]

In the present work, the distortion modes and ferroelectric properties of Sr3(Sn1−xZrx)2O7 (x = 0.0, 0.25, 0.5, 0.75, 1.0) ceramics with double-layered Ruddlesden–Popper structures were investigated. The amplitudes of three distortion modes for the ferroelectric phase deviated from the aristotype one were quantified using the symmetry-mode approach adopted in Rietveld refinement against x-ray diffraction patterns. The remanent polarization and the coercive field decreased with increasing the content of Zr4+ cations. The decline of polarization should attribute to the nonpolar secondary phase, while the suppression of a coercive field may connect with the decreased amplitude of the rotation mode. The Curie temperatures increased linearly with increasing x value in Sr3(Sn1−xZrx)2O7 ceramics, inducing from the decline of a tolerance factor. A typical first-order improper ferroelectric phase transition was determined using a differential scanning calorimetry measurement and dielectric characterization. From the present work, a straightforward way to quantify the amplitude of a distortion mode for the ferroelectric phase was given, and the ferroelectric properties could be effectively tuned by substituting the cations at the B site in the Sr-based hybrid improper ferroelectrics. [ABSTRACT FROM AUTHOR]

A Ti-ion ordering which correlates to the significant enhancement of the dielectric constant was determined in the (Ta2O5)0.92(TiO2)0.08 system by high resolution electron microscopy and the corresponding simulations. The alien Ti ions were determined to selectively sit on the octahedral locations in the Ta2O5 base structure in an average of 9-time period along the <110> direction. The authors suggest this Ti-ion ordering induces the directional enhancement of the dielectric permittivity of the (Ta2O5)0.92(TiO2)0.08 system. The atomic mechanism of this modulated structure contributing to the enhancement of the dielectric constant was qualitatively interpreted using a one-dimensional chain model. The structural correlations of the dielectric enhancement revealed in this study suggest a way to search or design high-k materials. [ABSTRACT FROM AUTHOR]

A new tannin-related compound named bistortaside A ( 1 ) and a known compound have been isolated from the rhizome of Polygonum bistorta L. A new compound was elucidated as 3-methyl-gallic acid 4- O -β-d-(6′- O -3″-methyl-galloyl)-glucopyranoside and a known compound was quercetin-3′- O -β-d-glucopyranoside ( 2 ) on the basis of spectroscopic analysis. [ABSTRACT FROM AUTHOR]

We report a 5 nm thick V-shaped AlGaAs/GaAs single quantum wire (QWR) that showed high photoluminescence (PL) thermal stability as a result of our recent progress in fabrication techniques. The integrated PL intensity of the QWR sample was quenched only by a factor of about 2.5 when the temperature was increased from 5 to 300 K. This sample also showed higher PL thermal stability over the whole temperature range than a 5 nm thick single quantum well reference sample grown under similar conditions. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Acanthopanax (A.) henryi (Oliv.) Harms contain many bioactive compounds commonly used in traditional Chinese medicine. The objective of the present study was to investigate the antibacterial activity of the single constituent, Eleutheroside K (ETSK) isolated from the leaves of A. henryi (Oliv.) Harms, against methicillin‐resistant Staphylococcus (S.) aureus (MRSA). Broth microdilution assay was used to measure the minimal inhibitory concentration (MIC) and the MIC values of ETSK against eight clinical S. aureus strains were all 50 µg ml−1. At sub‐inhibitory concentrations, a synergistic effect between oxacillin (OXA) and ETSK was confirmed using checkerboard dilution assay and time‐kill curve analysis. The bacteriostatic effect became more pronounced when ETSK was used in combination with detergent (Triton X‐100) or ATPase inhibitor (N, N′‐dicyclohexylcarbodiimide). According to western blot analysis, the down‐regulated expression of Penicillin‐binding protein 2a (PBP2a) further validated that the bacterial activity was inhibited when treated with ETSK in a dose‐dependent manner. Results based on our study verified that ETSK significantly suppressed MRSA infections and emphasized the potential application of ETSK as a novel anti‐MRSA natural drug. [ABSTRACT FROM AUTHOR]

A KTiOPO4 crystal block was used as a Fizeau interferometer. We modulated the interference pattern formed by the primary reflections from the front and rear surfaces of the crystal by the application of an electric field. The modulation is detected via a Faraday cell. In this way we measured the unclamped linear electro-optic tensor with high precision. [ABSTRACT FROM AUTHOR]

Dielectric properties of La2CuTiO6 ceramics were investigated in a broad frequency and temperature range. There is only one dielectric relaxation in the curve of temperature dependence of dielectric properties for La2CuTiO6 ceramics. This dielectric relaxation is a thermal activated process. The bulk and grain boundary resistances can be obtained from results of the least-mean-square fitting on impedance spectra. The conduction mechanism of the present ceramics is also a thermal activated process. The activation energy of dielectric relaxation is almost same as that of electrical conductivity and this indicates the closely correlation between the dielectric relaxation and electrical conductivity. The dielectric relaxation in the present ceramics should be attributed to the mixed-valent structure (Cu+/Cu2+ and Ti3+/Ti4+), which is induced from the oxygen vacancy. [ABSTRACT FROM AUTHOR]

Dielectric characteristics of Ba4Nd2Ti4Nb6O30 tungsten bronze ceramics have been investigated over a broad range of temperature and frequency. The real part of the dielectric constant ([variant_greek_epsilon]′) shows a sharp peak at 417 K indicating the ferroelectric phase transition. Two dielectric relaxations are observed in the lower temperature range, which are very obvious in the dielectric loss (tan δ) and the imaginary part of the dielectric constant ([variant_greek_epsilon]″). The differential scanning calorimetry (DSC), Raman scattering, and ultrasonic studies of the present ceramics have also been conducted in a broad temperature range covering the ferroelectric transition and/or the dielectric relaxation temperatures. The endothermal peak in the DSC curve around the ferroelectric transition temperature confirms the first-order structural transition with the transition enthalpy of 5.72 kJ/mol. Steplike anomalies in the wave number of the Raman vibrations and abnormal drop of the intensity of the Raman spectra are observed accompanying the ferroelectric phase transition. The dielectric relaxations in the temperature range below Tc are attributed to the structure fluctuations associated with the coupling between the polarizability in the ab plane and the c axis displacement, as well as the remaining random field effects, which are suggested as the possible origin of the anomalous reduction of the Raman intensity below Tc as well as the anomalies in the ultrasonic velocity and attenuation measurements. Freezing of these structure fluctuations are detected by the ultrasonic anomaly at about 120 K and the increasing Raman intensity below 150 K. [ABSTRACT FROM AUTHOR]

Structure and dielectric characteristics of Ba[(Fe0.9Al0.1)0.5Ta0.5]O3 solid solution were investigated. The cubic crystal structure in space group Pm3m(221) was confirmed in the Al-substituted Ba(Fe0.5Ta0.5)O3 ceramics. The extended giant dielectric constant step and the significantly reduced room-temperature dielectric loss were obtained in the Al-substituted Ba(Fe0.5Ta0.5)O3 ceramics. These improvements of dielectric characteristics have great scientific significance for potential application of giant dielectric constant materials. XPS analysis results confirmed that the low-temperature dielectric relaxation originated from the mixed-valent structure of Fe2+/Fe3+ and the hopping of the charge carriers between them, and the improvements of dielectric characteristics in the Al-substituted Ba(Fe0.5Ta0.5)O3 ceramics were attributed to the modification of such mixed-valent structure of Fe2+/Fe3+. [ABSTRACT FROM AUTHOR]

The plastic deformation features of intrinsic brittle-featured SiC nanowires by high resolution electron microscopy have been investigated. Strong plastic deformation strain fields were observed in a bent SiC nanowire. The achieved localized strain reaches about 1.5%. Localized lattice bending, atomic lattice disordering, and amorphization are contribution factors to achieve the plastic deformation. The projected Si–Si bonding angle distribution on the (110) atomic plane demonstrates the disordering features of the bent SiC nanowire. Buckling is found at the compressive side of the bent SiC nanowire. Growth bending can be achieved through {111} twinning and phase transformation from 3C to 2H. [ABSTRACT FROM AUTHOR]

Photoconductors based on V-grooved Al[sub 0.5]Ga[sub 0.5]As/GaAs multiple quantum wires (QWR) were fabricated. The geometric structure of the QWR was carefully characterized by transmission electron microscopy and spatially resolved microphotoluminescence measurements. Infrared response at 9.2 μm is observed from the photocurrent spectrum measured at 80 K. It is attributed as the intersubband transition in the quantum wire region. Due to the effective quantum confinement from the two (111)-surfaces forming the V groove, the overlapping between the ground state in the QWR and the one in the vertical quantum well is very small. This explains the weak photocurrent signal from the QWR photodetector. Theoretical design for a better wave function overlapping and optical coupling is outlined from the analysis of two-dimensional spatial distributions of the wave functions. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Ca3Ti2O7 with a Ruddlesden–Popper structure has received great scientific attention due to its high ferroelectric polarization. However, the optimization of hybrid improper ferroelectricity is still a challenging issue. In the present work, the remarkably improved ferroelectric polarization has been achieved in B-site co-substituted Ca3Ti1.8Al0.1Nb0.1O7 ceramic. The improved ferroelectric polarization in this ceramic stems from the higher ferroelectric activity of Nb5+ cations and a larger amplitude of oxygen octahedral distortion. Moreover, the more saturated electric hysteresis loops together with the higher ferroelectric polarization can be achieved under a higher electric field and at a lower frequency. The first-order phase transition nature is proved by the thermal hysteresis, while the Curie temperature is directly proportioned to the tolerance factor. The present work provides an effective way to improve the ferroelectric properties without declining the Curie temperature in Ca3Ti2O7-based hybrid improper ferroelectricities. [ABSTRACT FROM AUTHOR]

A response by X.Q. Liu and colleagues to a letter to the editor about their article "New Structural Picture of the Ge2Sb2Te5 Phase-Change Alloy," in a 2011 issue of the journal is presented.

The article focuses on a study related to the cherry stem rot and leaf necrosis disease caused by Phytophthora nicotianae in Yantai, China by X.L. Yu and others, which was published online in the 2015 issue of the periodical.

Initially, natalisin (NTL) was identified from three holometabolous insect species, Drosophila melanogaster, Tribolium castaneum and Bombyx mori, and was documented to regulate reproductive behaviours in D. melanogaster and T. castaneum. In this study, we report the sequences of the NTL precursor and its receptor (NTLR) from an important agricultural pest, Bactrocera dorsalis (Hendel). NTLR is a typical G-protein coupled receptor and phylogenetic analysis showed that B. dorsalis NTLR was closely related to insect natalisin receptors from other species. A functional assay of NTLR transiently expressed in Chinese hamster ovary cells showed that it was activated by putative natalisin mature peptides in a concentration-dependent manner, with 50% effective concentrations (EC50) at nanomolar or micromolar levels. As indicated by quantitative real-time PCR, both NTL and NTLR had the highest expression in the central nervous system of B. dorsalis compared with the other tested tissues. Three pairs of adult brain neurones of B. dorsalis were identified with immunohistochemical antibody staining against D. melanogaster NTL4, and in situ hybridization with specific DNA probes. Moreover, RNA interference mediated by double-stranded RNA injection in adults provided evidence for the important roles of NTL in regulating both male and female mating frequencies in this fly. [ABSTRACT FROM AUTHOR]

We report the first systematic investigation of the temperature-dependent carrier transferring processes of very short period V-grooved GaAs/AlGaAs quantum wire superlattice structures grown by flow rate-modulated metal-organic vapor phase epitaxy. The one monolayer (1 ML) fluctuation causes carrier confinement in sidewall (111) facet superlattice structures, and is shown to play an important role in the carrier transferring process. At low temperatures, the carrier transfer is blocked by the barriers of 1 ML fluctuation, while at high temperatures the carrier transfer from (111) superlattice to the wire region is shown to be very efficient after thermally overcoming the barriers. The temperature-dependent decay times of the different parts give direct evidence of the carrier transferring process, which demonstrates that the carriers can trap into the wire region within 50 ps at temperatures higher than 100 K. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The dielectric and ferroelectric characteristics of ( Sr x Ba1− x) Nb2 O6 unfilled tungsten bronze ceramics have been investigated together with the structure. The dielectric and ferroelectric characteristics of the present ceramics vary significantly with x, and the A1/A2-sites occupancy has been determined as the primary parameter governing this variation tendency. Ba ions tend to occupy A2-sites, Sr ions tend to occupy A1-sites, and one A1-site is empty. When the ratio of Sr/ Ba is close to 1:4 (where four A2-sites are just occupied by Ba ions, and one A1-site is occupied by Sr ion while another A1-site is empty), the normal ferroelectric transition is observed with one anomaly in the tanδ- T curve ( x = 0.25). When the ratio of Sr/ Ba is far away from 1:4, the typical relaxor behavior is indicated together with three anomalies in the tanδ- T curve ( x = 0.75). The incommensurate oxygen octahedral tilting and A-site random distribution are considered to be the structure origins for the relaxor ferroelectricity and low temperature dielectric relaxations. [ABSTRACT FROM AUTHOR]