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CrN/TiSiN multilayer coatings deposited at 316 L substrate were selected to explore the effects of irradiation on LBE (Liquid Pb–Bi eutectic alloy) corrosion. The as-deposited and irradiated coatings were exposed in LBE. After exposure, all CrN/TiSiN coatings presented oxidation accompanied with PbBi penetration. Irradiated coatings revealed better corrosion resistance with thinner oxide layer and smaller penetration thickness. The largest decrement of 39 % in oxidation thickness was observed in CrN/TiSiN deposited with Ti 80 Si 20 under 150 V. The irradiation-decelerated LBE corrosion could be attributed to the rapidly formed protective oxide layer resulting from the irradiation defects which accelerated nucleation and diffusion process during oxides formation. The decelerated effect was relatively weak in coatings deposited with a bias voltage under 100 V, in which the decrement is under 10 %. The enhanced corrosion resistance was attributed to the quickly formed dense and continuous chromium oxide which rapidly formed due to the irradiation induced defects and acted as diffusion barrier to slow down LBE penetration. [ABSTRACT FROM AUTHOR]

The dielectric constant measured by the LCR-meter is a differential-type, and is not equivalent to capacitivity. Capacitivity of ferroelectrics is the dielectric constant corresponding to electric hysteresis loop. Two kinds of dielectric constants are investigated based on the P-E loop mechanisms: turning effect of dipoles toward electric field direction, electric field-induced polarization effect, and dipole coupling effect. Numerical simulation of the theoretic equations exhibit adouble-peak of the differential dielectric constant, in which the distance between the two peaks depends on the temperature and the electric field. A much narrow static dielectric constant peak and negative peak appear corresponding to the loop. Mechanisms are analyzed schematically in detail. Definitions of differential- and static-dielectric constant are introduced and compared. Theoretic equations for the two dielectric constants are derived from the three effects. Variations of the two dielectric constants with E and T are demonstrated schematically. Mechanisms of the variations are explained in detail. [ABSTRACT FROM AUTHOR]

Local disordering has been analyzed in ordered intermetallic CoAl films epitaxially grown on GaAs(001) substrates by molecular beam epitaxy. Transmission electron microscopy investigations demonstrate the appearance of the bcc phase in the CoAl epilayer, which is the disordered version of the B2 crystal lattice type. Variations in the growth temperature between 100 and 300 °C reveal that the degree of thermal disordering and the volume fraction of the disordered bcc phase increase with increasing temperature. Interface reactions were observed in the sample fabricated at 300 °C resulting in the formation of CoAs precipitates at the interface. These precipitates contribute to the plastic relaxation of the 1.2% lattice mismatch between the CoAl film and the GaAs substrate affecting the strain-induced order–disorder transition. The impact of disordering is discussed in connection to the high diffusivity of vacancies and Co atoms existing in the intermetallic alloy. [ABSTRACT FROM AUTHOR]

The effects of constant bias stress and electric field on the electromechanical behavior of <001>-oriented Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (PMN–0.32PT) relaxor ferroelectric single crystals have been investigated. Both unipolar and bipolar responses are considered. Obtained results show that compressive bias stress with appropriate magnitude can significantly increase the piezoelectric constant. It is also found that bias electric field in the poling direction stabilizes the microstructure of PMN–0.32PT and reduces the hysteresis loss. The observed effects of bias stress and bias electric field on the electromechanical properties of <001>-oriented PMN–0.32PT single crystals can be interpreted in terms of phase-transformation-induced polarization rotation through intermediate phases. [ABSTRACT FROM AUTHOR]

Antiferroelectric double loops and double dielectric peaks occurred at an electric field circle synchronously are confirmed theretically by solving the kittel's function with the idea of different responses of dipoles to applied electric field (E) in E-direction and anti-E-direction in antiferroelectrics. By solving problem of inversion of dipoles to ferroelectric phase controlled by thermodynamic parameters and the antiferroelectric coupling coefficient in antiferroelectric phase, the numerically simulated results exhibit that antiferroelectric phase can transform to ferroelectric phase with two approaches: decrease in temperature to a critical temperature, and increase in parameter α0. The results are well coincident with experimental results. [ABSTRACT FROM AUTHOR]

Curbside bus stops and bus bays are mainstream forms of bus stops in China. There is no specific study available to assess and compare the safety performance of bus stops near intersections. The study provides insights into contributing factors that are positively or negatively related to the variation of the severity of conflicts between vehicles near curbside bus stops or bus bays in the vicinity of signalized intersections. The traffic conflict technique and the ordered probit model are developed to identify the contributing factors on conflict severity outcomes (potential, slight and serious). Results show that conflict-related variables are significantly different under two types of bus stops (location of the bus stop, distance from the intersection, traffic volume, number of dwelling buses, et al). There are more conflicts occurring near curbside bus stops under the same observation period, but the proportion of serious conflicts are higher around bus bays. Bus stops built downstream the intersection can help to decrease the severity level of conflicts from the point of view of vehicle safety. In addition, appropriate distance from the intersection, bus route design and non-motorized vehicle management are conducive to improving the level of road safety. This paper focuses on the conflicts between vehicles without considering the effects of these various options on the safety of pedestrians, the safety performance of bus stops deserves further research. [ABSTRACT FROM AUTHOR]

The existing studies on micro-texturing of cutting tools only tackle the micro-textures of uniform distribution. The theoretical and experimental bases are severely lacking for the effects of different micro-texture distributions on the anti-wear and anti-friction properties in titanium alloy cutting. To solve the problem, this paper attempts to explore the wear resistance and friction performance of micro-round-pit (MRP) textures in different distributions. Specifically, the DEFORM-3D finite-element method (FEM) software was adopted to simulate and analyse the effects of these distributions on the ball-end milling of titanium alloy. The simulation shows that the milling force was minimized by the distribution ABC (150-175-200). This result was then confirmed by a milling experiment. In conclusion, the tool wear and cutting friction can be effectively reduced by the optimal micro-texture distribution. [ABSTRACT FROM AUTHOR]

Graphical abstract Nanohardness of Ti-Si-N coatings decreased as the amorphization occurred after irradiation. The decrement first decreased with the decrease of grain size, then increased as the grain size further decreased to a size smaller than 9 nm. The thickness of amorphous layer and the decrement in hardness revealed similar trend as a function of grain size. Highlights • Ti-Si-N coatings with different grain size were irradiated by He+ ions. • Amorphization and hardness decrease were observed in all coatings. • Grain refinement enhanced the radiation tolerance in Ti-Si-N. • A grain size threshold for enhanced radiation tolerance existed. Abstract Materials with large fractions of interfaces (e.g. nanocrystalline materials and multilayered nanofilms) have attracted attention because of their significantly enhanced ability to tolerate severe irradiation environments. In this paper, the microstructure and nanohardness evolutions of Ti-Si-N nano-amorphous composite coatings with grain sizes from 5 nm to 12 nm were investigated using 50 keV He+ ion bombardment at room temperature. All samples contained amorphous layers that caused decreases in hardness. The amorphous layer thickness and hardness decrement first decreased with the grain size and then increased. Results suggested that the nano/amorphous interfaces in Ti-Si-N coatings can effectively promote defect annihilation during irradiation. However, radiation tolerance was optimized in materials with 9 nm grains due to the competition between the increase in free energy and the energy stored in defects (E sto). In addition, this paper proposed a mechanism that explained the associated decrease in hardness. These results provided the theoretical underpinnings for an understanding of nano-composite material radiation behavior under irradiation. [ABSTRACT FROM AUTHOR]

Graphite‐MoS2‐Fe2O3 (Fe3O4) nano‐composite lubricating coatings were prepared on the surfaces of non‐copper coated solid wires by a mechanical coating technique. The tribological behaviours of graphite‐MoS2‐Fe2O3 (Fe3O4) coatings at the rubbing interfaces of welding wires against the contact tube were investigated. The results demonstrate that the lubricating properties of graphite‐Fe3O4 coatings outperform the lubricating properties of graphite‐Fe2O3 coatings. The anti‐wear performance of the contact tube is strengthened with increasing nano‐MoS2 contents. Layers of protective tribofilms are formed at the rubbing interfaces of welding wires against a contact tube by tribochemical reaction among lubricants. The tribofilms are composed of FeO, MoO3 and FeMoO4 with excellent lubricating properties. They can avoid direct contact of welding wires against the contact tube, thus decreasing contact tube wear. With the transition of the contact tube wear from mild to severe, the dominant wear mechanisms of contact tube change from fatigue peeling and oxidative wear to abrasive wear and arc ablation. [ABSTRACT FROM AUTHOR]

Purpose Ti-Si-N coating with nanocomposite structure is a promising protective coating for cutting tools which will be subject to high temperature oxidation during service. This study aims to investigate the thermal stability of Ti-Si-N coatings and lays the foundation for its application in high speed dry cutting.Design/methodology/approach Nanocomposite Ti-Si-N coating was deposited on stainless substrate and silicon wafer (100) by Ti90Si10 alloy target by using cathodic arc ion plating. The microstructure of Ti-Si-N coating had been detected by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).Findings The results suggested that the coating was TiN nanocrystals with a diameter of 6.3 nm surrounded by amorphous Si3N4. The oxidation test was conducted under 550, 650, 750, 800, 850, 900 and 950°C for 2 h. The structure evolution was observed by Scanning electron microscope (SEM), energy dispersive spectrum (EDS), XRD and XPS. The results indicated that rutile has been formed at 650°C, while Si3N4 began to oxidized at 800°C. The grain size of TiN increased from 6.3 to 13 nm as the samples oxidized from 550 to 800. Micro-crack also formed in samples oxidized over 900°C.Originality/value Ti-Si-N coating, in this study, was deposited by cathodic arc ion plating using alloy target at high-bias voltage. The oxidation temperature ranged from 500 to 950°C with TiN coating as reference. [ABSTRACT FROM AUTHOR]

The effects of temperature on electrostrictive hysteresis loops of antiferroelectrics in the tetragonal phase are explored by a thermodynamic model based on Landau theory. Results of numerical simulation show butterfly shaped electrostriction-field hysteresis loops. With the increase in electric-field the strain increases rapidly due to rotations of dipoles and then slowly by field - induced polarization. When temperature decreases the contribution by the rotation increases and moves towards lower field. On the contrary, the field - induced polarization in modulated state has larger contribution to electrostriction. To identify the degree of modulated state a method is proposed that variations of electrostriction and dielectric constant with temperature are related to the degree on an increasing electric field. The simulated results are basically consistent with experimantal results of some antiferroelectrics. • Δ s (electrostriction)-E loop of AFE is derived by a 3D Landau-Devonshire theory. • Abnormal electrostriction loop caused by modulated state is derived. • Correlations between ε and Δs in various modulation states are demonstrated. [ABSTRACT FROM AUTHOR]

Reversible electrostrictive effect in ferroelectrics of double-well free energy is modeled using the Devonshire theory. The idea is developed that in tetrogonal phase 90° turnings of dipoles from four poling axises, isoenergetic minima, perpendicular to electrical field to the direction of electrical field cause electrostriction. Numerical simulation results exhibit that the exchanging coupling coefficient between dipoles results in a butterfly shaped electrostriction loop. Influences of temperature and the two parameters of materials on shape of electrostriction loop are discussed, and an empirical experimental law, about magnitude of electrostriction with the Curie constant, is confirmed. [ABSTRACT FROM AUTHOR]

Background Health workers' awareness and knowledge of transplantation medicine can improve people's sensitivity and reduce their degree of opposition to donations. The medical literature contains numerous examples of attitudes toward organ transplantation and donation aimed at university students or medical staff members, but rarely for transplantation nurses. Objective The purposes of the study were to investigate the attitudes toward organ transplantation and donation among transplantation nurses and to explore the impact factors. Methods The study was conducted in 37 transplantation surgery wards in 22 hospitals using cross-sectional approach. SPSS (International Business Machines Corporation, Armonk, New York, USA) 7.0 software was used to analysis descriptive and inferential statistics for data. Results Five hundred thirty-six effective questionnaires were received and the effective rate was 89.33%. Nurses' mean age was 28.40 years with a mean service length of 6.54 years. Among these nurses, 66.6% and 78.0% were willing to accept organ transplantation surgery for themselves and their relatives, respectively. Of these nurses, 33.4% would donate their organs after death; whereas 39.9% were uncertain. Only 38.2% were willing to register in the national organ donation system. Of these nurses, 28.2% were willing to sign the organ donation consent forms when their relatives became potential organ donors, and 45.7% were uncertain. Eight independent variables that affected nurses' attitudes toward donating their organs from most to least significant were: ratio of nurse to bed, title, employment form, age, length of service, position, monthly income, and the highest educational degree earned. Pearson correlation analysis showed a significant correlation among nurses' attitudes toward organ transplantation, organ donation, and online registration. Conclusion The attitude toward donation and transplantation in the hospitals was not too optimistic, and an improvement in the training regarding transplantation and donation among nurses in China is necessary. Nurses are an important group who generate opinion in the patient population, and their negative attitudes can have a significant negative impact on society's attitudes toward organ donation. [ABSTRACT FROM AUTHOR]

To promote the industrial application of high entropy alloy nitride (HEAN) coatings, the cathodic arc ion plating deposition process was explored to deposit FeCoCrNiAl0.1 N using casting HEA alloy targets. We investigated the impacts of nitrogen pressure and bias voltage on the microstructure, mechanical characteristics, and friction behaviors. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to analyze the microstructures. It was found that compositions for all coatings were uniformly and the coatings mainly consisted of FCC-HEA, CrN, AlN, and FeN phases. The nano hardness and plastic deformation resistance, characterized by nano-indentation, both increased with the nitrogen pressure and certain bias voltage (<150 V). Coating deposited with 2.0 Pa and 150 V presented the maximum hardness of 32.9 GPa and the highest H 3/ E 2 value of 0.1 GPa. The hardening mechanism was focused. Coatings deposited with low nitrogen pressure presented better crack resistance under scratch load. The friction behaviors were presented based on the combined studies of friction curves, wear track profiles, and morphologies. FeCoCrNiAl0.1 N coatings revealed excellent wear resistance with relatively lower COF (ranging from 0.43 to 0.51). [Display omitted] • FeCoCrNiAl0.1N coatings were deposited by CAIP using cast alloy targets. • The high hardness FeCoCrNiAl0.1N coating (32.9 Gpa) was achieved. • The grain size of the FCC and metal nitride phases within the coating should be responsible for the high hardness and resistance to plastic deformation. • Coatings deposited with CAIP show excellent scratch and abrasion resistance (0.43). [ABSTRACT FROM AUTHOR]

Polarization-electric field (E) hysteresis loop is crucial to ferroelectrics and their applications. First order phase transition ferroelectric has a transition region, where two phases coexist from ferroelectric phase at T 0 to paraelectric phase at T 1 , and stretching to an E -enhanced phase transition temperature T 2. Shape of the loops in the transition region changes with temperature confirmed by experiments. Evolution of the shape is derived by three-dimension Landau-Devonshire theory, on the basis of variations of E induced valleys of Gibbs free energy. The principles used are rotations of dipoles by the E to cause critical effect, and coupling between rotated dipoles to produce polarization hysteresis. The theoretic results exhibit that double loops converge to the origin and then separate when temperature rises through T 1. The reasons for the double loops are ascribed to combination of the critical effects for the abrupt changes in polarization and the coupling effect for the hysteresis between two critical points. The theory can explain the experimental phenomena. • Evolution of P - E loop is dominated by coupling and rotation effects in ferroelectrics. [ABSTRACT FROM AUTHOR]

Recently developed detectors can deliver high resolution and high contrast images of nanostructured carbon based materials in low voltage scanning electron microscopes (LVSEM) with beam deceleration. Monte Carlo Simulations are also used to predict under which exact imaging conditions purely compositional contrast can be obtained and optimised. This allows the prediction of the electron signal intensity in angle selective conditions for back-scattered electron (BSE) imaging in LVSEM and compares it to experimental signals. Angle selective detection with a concentric back scattered (CBS) detector is considered in the model in the absence and presence of a deceleration field, respectively. The validity of the model prediction for both cases was tested experimentally for amorphous C and Cu and applied to complex nanostructured carbon based materials, namely a Poly(N-isopropylacrylamide)/Poly(ethylene glycol) Diacrylate (PNIPAM/PEGDA) semi-interpenetration network (IPN) and a Poly(3-hexylthiophene-2,5-diyl) (P3HT) film, to map nano-scale composition and crystallinity distribution by avoiding experimental imaging conditions that lead to a mixed topographical and compositional contrast [ABSTRACT FROM AUTHOR]

Transition metal nitrides coatings have attracted extensive interests as radiation tolerant coating to separate the fuel and cladding in gas cooled fast reactor in recent years. This paper mainly focused on the influence of He + ion irradiation on microstructure and mechanical properties of Ti Si N coatings as a function of grain size. The results showed that amorphous layer on the top of Ti Si N layer has been formed in the post-irradiated coatings and lead to an obvious decrease in hardness and Young modulus. [ABSTRACT FROM AUTHOR]

TiN and Ti-Si-N (2.9 at.% and 5.0 at.% Si) coatings were fabricated on the surface of polished Si (100) wafers and stainless steel substrates by cathodic arc ion plating. The XRD results showed that the preferred orientation of the TiN crystals changed from TiN (111) to TiN (200) with an increasing silicon content. The TiN coating exhibited a polycrystalline structure with an average grain size of approximately 18 nm, while the Ti-Si-N coatings exhibited a nanocomposite structure of TiN nanocrystals embedded in amorphous Si 3 N 4 . In electrochemical impedance spectroscopy (EIS) tests, the amorphous Si 3 N 4 phase distributed on the boundaries of the Ti-Si-N (5.0 at.% Si) coating and acted as an effective barrier layer against the penetration of the corrosion solution, which resulted in better corrosion resistance compared with TiN and the lower-Si-content Ti-Si-N coating (2.9 at.% Si). Immersion tests and surface morphology observations of the samples after corrosion were also carried out to investigate the corrosion mechanism and behaviors of TiN and Ti-Si-N composite coatings. [ABSTRACT FROM AUTHOR]

Ti–Si–N coating has been widely reported with good thermal stability and excellent mechanical properties as protecting material for cutting tools. However, the coating thickness is usually in the range of 3–10 um by using PVD or CVD fabricating technique, which is not enough for the severe cutting environment. If the 2 dimensional ( 2-D ) Ti–Si–N film can be fabricated into 3-D bulk ceramic material, it should be a good candidate for high-speed or dry cutting conditions. In this paper, we try to investigate the relationship between microstructure and performance of Ti–Si–N bulk materials with different Si 3 N 4 concentration synthesized by spark plasma sintering (SPS). The microstructure, relative density and Vickers hardness were determined to investigate the effect of varied Si 3 N 4 contents. The results showed that Ti–Si–N bulk material exhibited typical nanocrystalline-amorphous structure similar with Ti–Si–N coating and outstanding mechanical performance. A maximum hardness of 2500HV 0.05 could be obtained at 10 at.% Si 3 N 4 content and the increasing Si 3 N 4 content will lower the relative density and hardness continually. [ABSTRACT FROM AUTHOR]

When the contributions of dipole and soften vibration mode are assigned to a complex impermeability and a real impermeability, respectively, the total complex permeability with frequency can be derived to modify the classical Landau-Devonshire theory. In a gaussian distribution and a skewed gaussian distribution of Curie temperature of second-order phase transition, the functions derived have the form of dispersion behavior of relaxor ferroelectrics. By comparing with experiment result, slight deviations appear on the two sides of peak of permittivity for the gaussian distribution, and improved by the skewed gaussian distribution. The relevant problems to be solved are proposed. [ABSTRACT FROM PUBLISHER]

BaTiO3 ceramics doped with 0.40 mol% NaNbO3 were prepared using a traditional approach by sintering at temperature of 1250 °C to 1290 °C. The prepared ceramics was characterized by very good dielectric properties, such as high dielectric constant (1.5 × 105), low dielectric loss (0.1), and good dielectric temperature stability in the −40 °C to 100 °C range for the sample sintered below 1270 °C. The dielectric characteristics obtained with XPS confirmed that Ti4+ ions remain in the state without any change. The huge increase in dielectric constant in NaNbO3 doped BaTiO3 samples occurs when large amount of Ba2+ ions are excited to a high energy bound state of Ba2+ − e or Ba+ to create electron hopping conduction. For samples with the content of NaNbO3 higher than 0.40 mol%, or sintering temperature higher than 1280 °C, compensation effect is dominated by cation vacancies with sharply decreasing dielectric constant and increased dielectric loss. The polaron effect is used to explain the relevant mechanism of giant dielectric constant appearing in the ferroelectric phase. [ABSTRACT FROM AUTHOR]

Preparation and optimization of AlCrO-based solar selective absorber is reported in this paper. The AlCrOx thin films were prepared on silicon and quartz substrates by cathodic arc ion plating. The chemical composition and structure of the thin films were measured by RBS, XRD and TEM. And the optical constants were obtained by modeling of the reflectance and transmittance spectra of the thin films on quartz substrates. A three-layered stack absorber was then designed using the optical constants. The effects of composition and thickness of individual layers in the stack on the reflectance spectra was systematically investigated, and an optimized absorptance of 0.942 was obtained. The optimized stack with Mo infrared reflective layer was deposited on silicon substrate, and very similar reflective behavior between the measured and simulated spectra was observed. The experimental absorptance and thermal emittance of the stack were 0.927 and 0.094, and the measured thicknesses by TEM of each layer were very close to the calculated thicknesses. [ABSTRACT FROM AUTHOR]

Gold nanoparticles with ZnO (sphere and rod) core–shell have been prepared from HAuCl4 containing aqueous solution using pot chemical and hydrothermal method. The nanoparticles were characterized by using X-ray diffraction, transmission electron microscopy, and UV–vis absorption spectroscopy. The effects of the concentration of zinc acetate, reaction temperature, and growth solution of zinc oxide were investigated. It was found that they strongly effect on the formation of the core–shell nanoparticles and optical properties of it. The high absorption peak in the visible region and more absorption intensity in UV region of Au/ZnO core–shell nanoparticles candidate it for photocatalytic applications. [ABSTRACT FROM AUTHOR]

Objective: To investigate the changes in paraspinal muscle cross-sectional area (CSA) and composition, using the digital data from lumbar spine MRIs of patients with acute and chronic low back pain (LBP). Methods: In total, 178 patients with unilateral LBP who had lumbar MRI examination were recruited. The data were obtained by a retrospective documentation audit. The CSAs and mean signal intensities of the bilateral paraspinal muscles [psoas major (PM), quadratus lumborum, multifidus (MF) and erector spinae (ES)] were measured, and the percentage of fat infiltration was calculated. The data between the painful side and non-painful side were compared, and between-group comparisons were tested. 42 patients with chronic unilateral LBP could indicate the problem level, and the CSA and mean signal intensity of the MF muscle were analysed at the problem level, and one vertebral above and one vertebral level below the problem level. Results: The CSAs of the PM and ES muscles were significantly decreased in the acute LBP group, while in the chronic LBP group, significant reduction in CSA was found in the MF and ES muscles on the painful side compared with the non-painful side. The mean signal intensity and fat content of the ES muscle on the painful side in the chronic LBP group was significantly higher than that on the painful side in the acute LBP group. The significant decrease of CSA in the MF muscle was found at multiple levels on the painful side. Conclusion: The present findings show that there is selective ipsilateral atrophy of paraspinal muscles, specific to the symptomatic side, in patients with acute and chronic LBP. The reduction of the muscle CSA and increased fatty infiltration occurred synchronously, and the extent of change is significantly greater in chronic LBP in the ES muscle. Atrophy of the MF muscle appears to be at multiple levels but side specific in relation to symptoms in patients with chronic LBP, and the decreased muscle CSA may occur prior to fatty infiltration. [ABSTRACT FROM AUTHOR]

Long-term thermal stability (LTTS) of the CrAlO-based selective absorbing coating deposited by cathodic arc ion plating was systemically investigated. The CrAlO-based coating consisted of columnar structured Mo layer, nano-multilayer structured low oxygen content Cr-Al-O layer (LOCL), as well as amorphous middle oxygen content Cr-Al-O layer (MOCL) and high oxygen content Cr-Al-O layer (HOCL), from substrate to surface. Absorptance (α) between 0.918–0.924 and emittance (ε) between 0.154–0.170 were obtained in the as-deposited coating. In order to investigate the LTTS of the coating in air, four as-deposited coatings were annealed at temperatures of 500, 600, 700, and 800 °C for 200, 200, 50, and 10 h, respectively. The compositions, structures, and surface morphologies of these coatings were characterized using SEM, EDS, XRD, TEM, Raman, and AFM, while the optical performances were measured by the spectrophotometers. Results showed that the CrAlO-based coating exhibited outstanding LTTS with a selectivity (α/ε) of 0.923/0.149 even after annealing at 500 °C for 200 h in air, as well as no obvious changes were detected on structure of the coating. At annealing temperature of 600 °C for 200 h, degradation of the nano-multilayer structured LOCL as well as a thin oxide layer formed on the coating surface were observed. At higher annealing temperatures of 700 °C for 50 h and 800 °C for 10 h, the degradation of the Mo layers and thicker oxide layers on the coating surfaces could be found. These obtained results indicated that the CrAlO-based selective absorbing coating with excellent thermal stability could be a promising material for photo-thermal conversion at temperatures higher than 500 °C. [ABSTRACT FROM AUTHOR]

The short time oxidation behaviour of Super304H was studied at 700°C for different periods. The structure and composition of the oxide layers were investigated using line scanning of scanning electron microscopy equipped with energy dispersive spectroscopy (EDS). In the sample oxidised for 4 h, a double layer scale consisting of outer magnetite layer and inner chromium rich iron oxide was observed from the cross-section. The EDS results from oxide layer surfaces of other three samples showed that no obvious outer layer can be observed after 3 h oxidation. The oxide phases have been identified by X-ray diffraction and Raman spectrum. Atomic force microscopy was used to reveal the mechanism of early oxidation stage of Super304H on samples oxidised for 1·5, 2 and 3 h, respectively. The roughness of the layer surface increased with increasing oxidation time in the early stage, which is in accordance with the proposed model and indicates that the columnar nickel oxide in the specimen is connected to the formation of chromium oxide. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiSiN/CrN coatings with different Si and bias voltage have been deposited for He irradiation. • Amorphization and bubbles were observed in irradiated coatings which led to softening effect and hardening effect, respectively. • The layer interface could effectively increase the radiation tolerance of nano-amorphous coatings. • Coherent interface formed by epitaxial growth reduced the bubble density at layer interface and lowered the risk of interface embrittlement. Interface engineering such as grain refinement, multilayer structure was reported to be efficient strategy to enhance the irradiation tolerance by promoting the defects annihilation. However, rapid accumulation of helium atoms at interface would lead to high density bubbles and induce interface crack. In this study, we propose a new strategy to address the root causes of bubble formation by releasing He through the designed coherent interface (CI) which is formed by epitaxial growth between two sublayers without sacrifice the mechanical properties. To reveal the enhancement of CI on the irradiation tolerance, the mechanical properties and microstructure evolution of TiSiN/CrN multilayers have been investigated before and after He+ irradiation. TiSiN/CrN coatings reveal obvious amorphization at top-surface and large amount of bubbles have been observed at interfaces. The variation of hardness of the irradiated coatings depends on the competition between softening effect and hardening effect, induced by amorphization and bubble respectively. With the formation of CI across the sublayers, He atoms diffuse through the CI to deeper area beyond the ion projected range, decreasing density and size of the bubble at layer interface. Therefore, we present a new strategy of designing protective multilayer coatings for nuclear reactor through the introduction of CI. [ABSTRACT FROM AUTHOR]

Nanoindentation has been recently used to measure the mechanical properties of polycrystalline graphene. However, the measured failure loads are found to be scattered widely and vary from lab to lab. We perform molecular dynamics simulations of nanoindentation on polycrystalline graphene at different sites including grain center, grain boundary (GB), GB triple junction, and holes. Depending on the relative position between the indenter tip and defects, significant scattering in failure load is observed. This scattering is found to arise from a combination of the non-uniform stress state, varied and weakened strengths of different defects, and the relative location between the indenter tip and the defects in polycrystalline graphene. Consequently, the failure behavior of polycrystalline graphene by nanoindentation is critically dependent on the indentation site, and is thus distinct from uniaxial tensile loading. Our work highlights the importance of the interaction between the indentation tip and defects, and the need to explicitly consider the defect characteristics at and near the indentation site in polycrystalline graphene during nanoindentation. [ABSTRACT FROM AUTHOR]

Abstract: A novel four-layer structured Cr–Al–O tandem nano-multilayer composite coating has been prepared by cathodic arc ion plating for solar selective absorbing. The four-layer structured coating consists of pure chromium layer, low oxygen content Cr–Al–O layer (LOCL), middle oxygen content Cr–Al–O layer (MOCL) and high oxygen content Cr–Al–O layer (HOCL). The composition, structure, and surface morphology of the coating were characterized using SEM, EDS, XPS, TEM, and AFM. The optical performances of the coating were measured by spectrophotometer, while the thermal stability of the coating was evaluated by Raman spectroscopy. Results showed that LOCL and MOCL, in which amorphous Cr–Al–Ox nanolayers and composite Cr–Al–Ox nanolayers embedded with Cr2Al nanograins alternated with each other, were the main absorbers, while HOCL acted as an antireflection layer. The coating exhibited a relatively high absorptance of 0.924 and a relatively low emittance of 0.21, as well as an outstanding thermal stability with a selectivity of 0.919/0.225 even after annealing at 700°C for 2h in air, which properties rendered the four-layer structured Cr–Al–O tandem coating a potential material for photo-thermal conversion at high temperatures. [Copyright &y& Elsevier]

Abstract: Ba0.8Sr0.2TiO3 ceramics doped with Y2O3 from 0 to 0.10 mol% exhibit normal ferroelectric phase transition, while the ceramics doped with Y2O3 from 0.20 to 0.30 mol% show a giant dielectric constant behavior with loss less than 0.15 at 1 kHz from −40 °C to 140 °C, which is suggested due to semiconductive grain and the Maxwell–Wagner effect by structure disordering in grain boundary. The analyses of unipolar charge for the semiconductive grain indicate three kinds of dielectric processes: thermally stimulated process of unipolar hopping, dispersion process of dielectric constant with frequency, and phase transition process accompanied with disappearance of giant dielectric constant in cubic phase. The XPS results confirm that some of the barium ions are in low energy state to form e-Ba2+ and to provide hopping sites for electrons. The ceramics doped with Y2O3 from 0.50 to 0.75 mol% recover the normal ferroelectricity. The possible mechanics are relevant to binding effect of cation vacancies on electrons. [Copyright &y& Elsevier]

Abstract: Introduction: Both mannose-binding lectin (MBL) and ficolin (FCN) interact with carbohydrate structures on microbial surfaces. Polymorphisms at the promoter and exon 1 of the MBL2 gene, which are responsible for low serum levels of MBL, have been shown to play important roles to increase the risk of post-transplant infections. Three gene polymorphisms in the promoter region of FCN2 and 2 in exon 8 (+6424 G > T) are associated with serum levels of FCN2 or binding capacity toward N-acetylglucosamine on microbial surfaces. Methods: We prospectively analyzed 81 kidney transplant recipients for 6 well-known functional single-nucleotide polymorphisms in the MBL2 and 5 in the FCN2 gene of the recipients determined by gene sequencing. The bloodstream infections collected prospectively were associated with MBL2 and FCN2 genotypic variants over the first year after kidney transplantation. Results: Multivariate analyses only found an association of recipient QQ + PQ genotypes of MBL2 5′-UTR +4 (odds ratio [OR] = 3.677, 95% confidence intervals [CI] = 1.127–11.998, P = .031) and FCN2 exon 8 Thr 236 Met(+6359 C > T) (OR = 4.917, 95% CI = 1.229–19.667, P = .024) with the incidence of bacteremia. Conclusion: Recipient QQ + PQ genotypes of MBL2 5′-UTR +4 and recipient FCN2 exon 8 Thr 236 Met(+6359 C > T) variants showed significant impacts on the risk of developing bloodstream infections after kidney transplantation. [Copyright &y& Elsevier]

Abstract: Introduction: Pneumonia remains a significant cause of morbidity and mortality after kidney transplantation. The present study was therefore conducted to investigate whether or not the polymorphisms of tumor necrosis factor (TNF)β, interleukin (IL)-10, IL-1β, and IL-1 receptor antagonist (IL-1ra) gene predicted the susceptibility to pneumonia within the first year after kidney transplantation. Methods: Subjects comprised 33 kidney transplant recipients with pneumonia and 63 noninfected kidney transplant recipients. Genomic DNA from these 96 kidney transplant recipients was extracted from peripheral blood leukocytes. The regions containing the NcoI polymorphic site at position +252 of TNFβ gene, the RsaI polymorphic site at position −592 of IL-10 gene, and the AvaI polymorphic site at position −511 of IL-1β gene were amplified by polymerase chain reaction (PCR) and subsequently digested with NcoI, RsaI, and AvaI restriction enzyme, respectively. The polymorphic regions with intron 2 of the IL-1 ra gene (IL-1 RN) containing variable numbers of a tandem repeat of 86 base pairs, were amplified by PCR. Results: Univariate analysis showed that recipient IL-10, IL-1β, and IL-1 RN polymorphisms were not associated with the presence of pneumonia (P = .589, .940, and .286, respectively). However, compared with GG genotype, recipient TNFβ +252AA + AG genotype was significantly associated with susceptibility to pneumonia (P = .006). Age of 45 years or older was not significantly associated with susceptibility to develop pneumonia but had a tendency to develop it (P = .119). After adjusting for age of 45 years or older, recipient TNFβ+252 AA + AG genotype (odds ratio = 5.366, 95% confidence intervals = 1.470 − 19.589, P = .011) independently predicted the risk for pneumonia within the first year after kidney transplantation in the multivariate analysis. Conclusion: These results suggested that recipient TNFβ gene polymorphism may be useful in predicting pneumonia, hence identifying individuals who could benefit from preventive treatment and a less potent immunosuppression regimen. [Copyright &y& Elsevier]

The role of hydrogen peroxide in the regulation of glucose-6-phosphate dehydrogenase (G6PDH) activity in the red kidney bean ( Phaseolus vulgaris L.) roots under salt stress (100 mM NaCl) was investigated. Salt stress caused the increase of the activities of G6PDH and antioxidative enzymes including ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), as well as HO production. The application of HO (1 mM) also enhanced the activities of G6PDH as well as antioxidative enzymes. In the presence of exogenous CAT, HO content was decreased, and the enhanced activities of G6PDH and antioxidative enzymes induced by NaCl or by exogenous HO were also abolished, suggesting that the enhancement of the above enzyme activities under salt stress was a result of the increased endogenous HO levels. Further results showed that the effects of NaCl and HO on the activities of antioxidative enzymes were diminished by NaPO (a G6PDH inhibitor), suggesting G6PDH activity is required in enhancing the activities of antioxidative enzymes. The enhanced membrane leakage, lipid peroxidation, HO and O - contents, G6PDH and antioxidative enzyme activities under salt stress were all recovered to control level when the red kidney bean seedlings treated with 100 mM NaCl for 6 d were transferred to the control conditions for 8 d. [ABSTRACT FROM AUTHOR]

Mobile station (MS) localisation, which plays an important role in the process of target continuous localisation, has received considerable attention. In this study, a new framework based on subspace approach for positioning an MS at three or more base stations (BSs) with the use of time-of-arrival (TOA) measurements is introduced. It is shown that the proposed approach is a generalisation of the mobile localisation method based on multidimensional scaling (MDS) analysis. Through computer simulations and computational complexity analysis, the authors can see that the proposed algorithm has a comparable performance with conventional MDS localisation method, however, the computational complexity has been greatly reduced. [ABSTRACT FROM AUTHOR]

Abstract: Ba0.8Sr0.2Ti1−5x/4Nb x O3 ceramics, x =0, 0.01, 0.05, 0.10, were fabricated by conventional solid-state reaction. With increasing niobium content the ferroelectric phase transition temperature decreases linearly, and the dispersivity of the transition increases. Niobium B-site decreases transition temperature more pronounced than Sr2+ at A-site. The heterovalent substitution of Nb5+ in low content causes local defect dipole, while more substitutions introduce disorder to disturb the long-range dipole correlation. Ba0.8Sr0.2Ti1−0.5/4Nb0.1O3 ceramic shows weak ferroelectric loop at room temperature far from its transition temperature, 153K. [Copyright &y& Elsevier]

orbate peroxidase (APX) is an important enzyme to scavenge the reactive oxygen species (ROS), which are often caused by the salt stress. Here, APX cDNA from Brassica napus was amplified by RT-PCR and cloned into the prokaryotic expression vector pGEX-6p-1 to express BnAPX as a glutathione S-transferase (GST) fusion protein. The recombinant expression plasmid was then transformed into Escherichia coli BL21 (DE3) and induced with 0.2 mM IPTG at 28°C. The enzyme activity analysis of the induced protein showed the GST-APX protein had the similar enzyme activity with the other found APXs, which decompose HO. Moreover, the GST-APX fusion protein was purified by affinity chromatography using the glutathione-Sepharose 4B column. The purified GST-APX protein was then used to immunize rabbits to obtain the anti-BnAPX serum, which was suitable to recognize both the recombinant exogenous BnAPX and the endogenous BnAPX in vivo by western blotting and the immunohistochemical experiment. Furthermore, the immuno-fluorescent microscopy observation revealed that BnAPX was expressed in the chloroplasts. Finally, the bacteria expressing BnAPX grew much faster in the presence of 3% NaCl than the control cells, indicating that the transformant expressing BnAPX acquired resistance to salt stress. [ABSTRACT FROM AUTHOR]

Localisation of mobile station (MS) has now gained considerable attention. It is not possible to further reduce the root mean square error using the existing location methods without additional information. This study proposes a method to improve the accuracy of mobile location using statistical characteristics of MS position as prior information. In this technique, the Chan-Ho method is extended from the maximum likelihood estimator (MLE) to the minimum mean square error estimator (MMSEE). The Cramer-Rao lower bound and theoretical variance of the proposed method are derived. The theoretical proof and simulations show that the proposed MMSEE has the better performance than the MLE. [ABSTRACT FROM AUTHOR]

Diabet. Med. 27, 1312-1317 (2010) Aims Lipotoxicity has recently been shown to be an important risk factor underlying the pathogenesis of pre-diabetes. However, clinical evidence supporting the treatment of pre-diabetes by improving lipotoxicity is lacking. Here, we conducted an open-label, randomized, controlled trial to investigate whether fenofibrate, the widely used hypolipidaemic agent, might benefit pre-diabetes, with metfomin and diet control, the recommended intervention methods, as positive controls. Methods Newly diagnosed pre-diabetes patients ( n = 120) with hypertriglyceridaemia (plasma triglyceride levels between 1.8 and 4.5 mmol/l) were randomly assigned by computer-generated randomization sequence to either control group (no intervention), fenofibrate group (200 mg once a day), metformin group (500 mg three times a day) or diet-controlled group (diet recommendation). Plasma biochemistry examination was performed every 2 months. The primary endpoint was the outcome of the natural course of pre-diabetes, evaluated by oral glucose tolerance test after 6-month follow-up. Results Twenty subjects in the fenofibrate group, 24 subjects in the metformin group and 25 subjects in both the diet-controlled group and the control group finished the trial. Fenofibrate, metformin and diet control had protective effects on hypertriglyceridaemic pre-diabetes, evidenced by 53.3, 70 and 30% participants regressed to normoglycaemia, respectively. The effects of fenofibrate and metformin were comparable ( P > 0.05), while diet control was less effective ( P < 0.05). Liver damage occurred in six subjects in the fenofibrate group and gastrointestinal symptoms occurred in four subjects in the metformin group. No serious adverse events occurred. Conclusion Controlling lipotoxicity by fenofibrate could effectively ameliorate the natural course of hypertriglyceridaemic pre-diabetes. [ABSTRACT FROM AUTHOR]

Abstract: On the basis of the analysis of liquid molecules coordinated with their nearest neighbors during cooling, a correspondent congregation model is presented for the vitrification process in supercooled liquid. The potential energy of conformers congregated together is described by Lennard–Jones–Gauss potential. It is shown that there exists universal correlation between fragility and congregation. The results suggest that a liquid is of more fragile property with lower coordination energy. A modified Vogel–Tammann–Fulcher equation is derived from temperature dependent coordination energy, and correlation between fragility and temperature on colloidal system is discussed. [ABSTRACT FROM AUTHOR]

A robust and low-complexity parameters estimation method, which combines TLS-ESPRIT and sparse signal representation (SSR) to estimate the parameter of coherently distributed sources is presented. The central direction-of-arrivals are estimated by TLS-ESPRIT based on approximate rotational relationship between two identical uniform linear arrays (ULAs), and angular spreads are given by basis selection method using SSR. Hence the method is a low-complex estimator that does not need a search in one or two-dimensional parameter space. And it owns more robustness in estimating angular spread than one-dimensional distributed source parameter estimator (DSPE). In addition, our method can estimate parameters of the sources with different angular signal distribution functions, which DSPE cannot work. The simulation results prove the effectiveness of our method. [ABSTRACT FROM AUTHOR]

Abstract: The beneficial effect of titanium ion implantation on the oxidation behaviour of zircalloy-4 at 500°C was investigated. Titanium ions were implanted by a MEVVA source at an energy of 40keV with dose 5×1016, 1×1017, and 2×1017 ion/cm2 at the maximum temperature 130°C. Weight gain curves of the as-received and implanted zircalloy-4 were measured after oxidation in air at 500°C for 100min. It was found that improvement was achieved in the oxidation behaviour of titanium ion implanted samples compared with that of the as-received one. The valence of the oxides in the scale was analyzed by X-ray photoemission spectroscopy. Glancing angle X-ray diffraction was used to examine the phase transformation in the oxide films and is showed that the addition of titanium transformed the phase from monoclinic zirconia to hexagonal zirconia. Finally, the mechanism of improvements oxidation behaviour is discussed. [Copyright &y& Elsevier]

The electric field induced “butterfly” curves and polarization loops, and the stress induced strain and polarization responses of [001], [011] and [111] oriented Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 (PMN-0.32 PT) relaxor ferroelectric single crystals have been systematically investigated by experiment study. The focus is on the effect of constant compressive bias stress on the electromechanical coupling behavior along three crystallographic directions of PMN-0.32 PT single crystals. Dependence of the coercive field, remnant polarization, dielectric constant, and piezoelectric coefficient on the bias stress has been quantified for PMN-0.32 PT single crystals oriented in three different directions. Obtained results show that the large piezoelectric responses under zero compressive stress in [001] and [011] orientation are dominated by intrinsic crystal lattice while the engineered domain structure has a relatively minor effect. It is found that observed responses under stress cycle for [001] oriented crystals are due to polarization rotation and phase transformations. However, those for [011] and [111] oriented crystals are due to domain switching. The “butterfly” curves and polarization loops driven by electric field under different bias compression are described by two non-180° domain switching. [ABSTRACT FROM AUTHOR]

Abstract: The electric field and the stress induced strain and polarization responses of [001], [011] and [111] oriented Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (PMN–0.32PT) relaxor ferroelectric single crystals have been systematically investigated by experimental study. The responses of [001] oriented single crystal to stress cycle and electric field are explained by polarization rotation and phase transformations mechanism. However, the responses of [011] and [111] oriented single crystal should be explained by domain switching. The differences of strain and polarization between the minimum and maximal values of electric field in [001] orientation firstly increase then decrease with enhancing of compressive stress. [Copyright &y& Elsevier]

Effect of compressive pre-stress and biased electrical field on the uniaxial electromechanical behavior of a soft ferroelectric ceramic PZT-53 is investigated. The emphasis is on the effect of electric and mechanical loading history upon the response of PZT-53 to external loading and on the effect of pre-stress and biased electrical field upon the electro-mechanical coupling behavior. It is found that the uniaxial behavior of the PZT-53 is sensitive to the compressive pre-stress and biased electrical field, and is less sensitive to the loading history. Obtained results are expected to shed insightful light on developing reliable constitutive model for ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

BACKGROUND: The mechanism by which chronic alcohol consumption impairs insulin sensitivity is unclear. We investigated the role of the Gs alpha-mediated pathway in decreasing insulin sensitivity in skeletal muscle after ethanol consumption. METHODS: Sixty male Wistar rats, divided into four groups, received either distilled water (controls; group I) or ethanol, which was administered by a gastric tube as a single daily dose of 5 g/kg (group II), 2.5 g/kg (group III), or 0.5 g/kg (group IV). After 20 weeks, fasting plasma glucose and serum insulin levels were measured. The hyperinsulinemic-euglycemic clamp study was performed under anesthesia to estimate whole-body insulin sensitivity. Insulin-stimulated glucose uptake was measured in vitro in dissected gastrocnemius muscle. Expression of glut4, Gs alpha, and Gi alpha was quantified using real-time PCR analysis and western blotting. cAMP levels were measured by ELISA. RESULTS: Compared with controls, the following observations were made: (1) the hyperinsulinemic-euglycemic clamp study revealed impaired insulin action at the whole-body level after ethanol treatment; (2) chronic ethanol feeding at 5 g/kg and 2.5 g/kg significantly decreased both basal and insulin-stimulated glucose uptakes in isolated skeletal muscle (p<0.05), which was accompanied by decreased expression of glut4 (p<0.05); (3) Gs alpha (mRNA and protein) expression in skeletal muscle was significantly increased in all three ethanol groups (p<0.05), and cAMP levels were also increased by ethanol treatment (p<0.05); and (4) there was no significant change in Gi alpha expression in all three ethanol groups. CONCLUSIONS: Chronic ethanol exposure decreased insulin-induced glucose uptake in rat skeletal muscle, which was associated with increased expression of Gs alpha. Because Gs alpha is a negative regulator of insulin sensitivity, the alteration in Gs alpha expression may contribute to the ethanol-induced impairment of insulin signal transduction. [ABSTRACT FROM AUTHOR]

Rod-shaped and wire-shaped SnO2 nanowhiskers were synthesized by thermal evaporating of tin powders at 900 °C. Three Raman peaks (474, 632, 774 cm-1) showed the typical feature of the rutile phase of as-synthesized SnO2 nanowhiskers, which was consistent with the result of x-ray diffraction. A relatively low turn-on field of 1.37 V µm-1 at a current density of 0.1 µA cm-2 was obtained. The dependence of emission current density on the electric field followed a Fowler–Nordheim relationship. Our results indicated that SnO2 nanowhiskers had an interesting FE property as a wide band gap semiconductor. [ABSTRACT FROM AUTHOR]

Large area, self-assembled Au–Si alloy nanocones are synthesized by vacuum electron-beam evaporation method at 450 °C. The formation mechanism is discussed based on the stress effect, interface energy, and Au–Si alloying process. The electron field emission properties of the self-assembled nanocones are studied based on current–voltage measurements and the Fowler–Nordheim equation. Low turn-on field (10 V/μm) with relatively high current density is obtained due to the nanocone-shaped structures with relatively rough morphology. The process temperature is lower than the melting point of ordinary glass. So our method is of great significance to the low-cost vacuum field emission devices fabrication. [Copyright &y& Elsevier]

High-vacuum electron-beam evaporation method is used for large area, metal-nucleated germanium (Ge) nanodots and nanocones on Si3N4/Si preparation. Nanodot and nanocone arrays with uniform size in bulk-quantity are synthesized using titanium (Ti) nanocrystals as nucleating center at 750 °C with different Ge deposition amount, respectively. The morphology evolution from nanodot to nanocone is studied by atomic force microscopy (AFM). The structure of the prepared sample is characterized by X-ray diffraction (XRD) and Raman scattering. Ge nanocones formed by this convenient fabrication process could have potential applications on nanoelectronics and vacuum electron field emission. [Copyright &y& Elsevier]

A new method, high-vacuum electron-beam co-evaporation is used to prepare silicon nanocrystals (Si NCs) embedded in Al2O3 dielectric matrix in the form of thin films. Silicon and Al2O3 are co-evaporated by two electron guns at the same time at room temperature with the pressure below 1×10−5 Pa. After evaporation, annealing in N2 ambient at 500 and 800 °C for 1 h is performed. X-ray diffraction and atomic force microscopy are used to estimate the diameter of the Si NCs and check the morphology of the co-evaporation film respectively. X-ray photoelectron spectroscopy is used to investigate the chemical state of Si and Al in the as-prepared and annealed samples. Electrical properties of the Si NCs are investigated and resonant tunneling due to three dimensional quantum confinements is observed at room temperature. [Copyright &y& Elsevier]