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Formation of Ag precipitates in an Al–1 wt%Ag alloy after aging at different temperatures was studied by positron annihilation spectroscopy. It is found that the aggregation of Ag atoms takes place during natural aging process after the Al–Ag alloy was homogenized at 550 °C and quenched to room temperature water. The Ag nanoclusters could trap positrons and thus positron annihilation measurements give information on the precipitation of Ag atoms. After artificial aging at 120 °C, the Ag signal is enhanced, which indicates further aggregation of Ag atoms. However, after artificial aging of the sample at 200 °C, no Ag nanoclusters are observed. Instead, the quenched-in vacancies show gradual recovery during this aging process. This is probably due to the dissolving of Ag clusters into Al matrix at 200 °C. Furthermore, after the sample was first heat treated at 200 °C and then aged at 120 °C, Ag nanoclusters appear again. This implies that the formation of Ag precipitates during natural aging process is assisted by the quenched-in vacancies. Temperature dependence of the positron annihilation measurements indicates that Ag nanoclusters are shallow positron traps, which makes it difficult to observe the real-time Ag precipitation formation by positrons during artificial aging of Al–Ag alloy. [ABSTRACT FROM AUTHOR]

Zn 1− x Cd x O nanocrystalline powder with different Cd contents (0≤ x ≤1) has been prepared by new facile sol–gel route. The crystal structure and optical properties were investigated by X-ray diffraction patterns, Transmission electron microscope, X-ray photoelectron spectroscopy, Photoluminescence. As x varied from x =0 to 0.25, the Zn 1− x Cd x O nanopowder exhibits a hexagonal wurtzite structure of pure ZnO without any significant formation of a separated CdO phase. For the samples with 0.5≤ x ≤0.85, the Zn 1− x Cd x O nanopowder exhibits the coexistence of hexagonal ZnO and cubic CdO phase, meanwhile, the content of ZnO phase decreases while that of CdO increases with increasing the Cd content x . The ultra-violet near-band-edge emission of the Zn 1− x Cd x O nanopowder was monotonously red-shifted from 389 nm ( x =0) to 406 nm ( x =0.25) due to the direct modulation of band gap caused by Cd substitution. [ABSTRACT FROM AUTHOR]

Zn 1−x Cd x O nanopowder in a wide range of Cd contents has been obtained by hydrothermal synthesis method. Synthesized nanopowder was characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, Transmission electron microscopy and Photoluminescence. As x varies from 0 to 1, it was observed that the crystal structure changes from wurtzite (ZnO) to mixture of wurtzite and cubic, and finally to cubic (CdO) structure. The wurtzite-type structure of ZnO can be stabilized up to nominal Cd content x ~0.1 without cubic CdO phase separation. For the Zn 1−x Cd x O nanopowder with wurzite structure, a significant change was observed in ultra-violet near-band-edge emission with variation in Cd content x . The change is attributed to the direct modulation of band gap caused by Zn/Cd substitution. [ABSTRACT FROM AUTHOR]

Antiferroelectric (AFE) materials attract widespread attention due to their unique behavior under electric field. In this work, the Pb 0.82 La 0.12 (Zr x Ti 1-x)O 3 (PLZT) films with Zr/Ti ratios close to the AFE region are deposited on the LaNiO 3 /SiO 2 /Si substrate through chemical deposition method. The dielectric, leakage, and ferroelectric performance of PLZT films are thoroughly examined. It can be concluded that the Zr content in PLZT films can effectively regulate their dielectric properties. At the same time, the increase of Zr/Ti ratio makes the double hysteresis loop of PLZT more obvious, leading to greater stability of the AFE phase, providing a significant advantage in energy storage. Notably, the PLZT film with a Zr/Ti ratio of 95/5 exhibits the highest recoverable energy storage density (W rec) of 30.8 J/cm3 and energy storage efficiency (η) of 71.5 %. These results reveal that the Zr/Ti ratio in PLZT antiferroelectric films plays a critical role in enhancing their energy storage performance. • PLZT films with different Zr/Ti ratios are investigated. • The best energy storage performance achieving W rec of 30.8 J/cm3 and η of 71.5 %. • The stability of antiferroelectric can be improved by increasing the Zr/Ti ratio. • The high switching field benefits energy storage performance in antiferroelectric. [ABSTRACT FROM AUTHOR]

Abstract: Classical shear beams only consider the deflection resulting from sliding of parallel cross-sections, and do not consider the effect of rotation of cross-sections. Adopting the Kausel beam theory where cross-sectional rotation is considered, this article studies stability and free vibration of axially-loaded shear beams using Engesser’s and Haringx’s approaches. For attached mass at elastically supported ends, we present a unified analytical approach for obtaining a characteristic equation. By setting natural frequencies to be zero in this equation, critical buckling load can be determined. The resulting frequency equation reduces to the classical one when cross-sections do not rotate. The mode shapes at free vibration and buckling are given. The frequency equations for shear beam-columns with special free/pinned/clamped ends and carrying concentrated mass at the end can be obtained from the present. The influences of elastic restraint coefficients, axial loads and moment of inertia on the natural frequencies and buckling loads are expounded. It is found that the Engesser theory is superior to the Haringx theory. [Copyright &y& Elsevier]

Abstract: Electronic structure, Born effective charges, and spontaneous polarization of multiferroic single crystal BiMn2O5 have been investigated in the framework of density functional theory. The relative stability of the ground state and the origin of multiferroicity for magnetism and ferroelectricity are addressed. The results reveal that the stability of antiferromagnetic (AFM) state is better than the ferromagnetic (FM) and ferrimagnetic configurations. The Born effective charge tensors (Z ⁎) have been calculated for this compound using a Berry-phase approach, compared to their nominal ionic values, the Z * of Mn atoms show anomalous difference. By investigating the electric structure of BiMn2O5, there exists obviously hybridization between Bi 6s and O 2p states, our calculations indicate that the 6s2 lone pair on the formally trivalent Bi ion plays an important role in inducing the ferroelectric distortion. [Copyright &y& Elsevier]

Abstract: Reactions between HfO2 and Si in HfSiO films during deposition and post-annealing have been studied. Intermixing of HfO2 and Si is achieved by radio frequency sputtering with HfO2/Si compound targets, and post-annealing is used to promote the reaction at different temperatures. The structural characteristics of the mixture, HfSiO films, are analyzed by X-ray photoelectron spectroscopy and X-ray diffraction, and a careful assessment of chemical states is performed for precise identification. XPS results show that with ratios of Si:Hf ranging from 0 to 0.3 in HfSiO films, Si fully reacts with HfO2 to form silicate during deposition. However, SiO2 appears when the ratio of Si:Hf rises to 1.2. When the annealing temperature reaches 600°C, decomposition of hafnium silicate is observed and hafnium silicide forms in the bulk of the films. XRD results reveal that HfSiO films remain amorphous with the annealing temperature below 600°C but crystallize at 800°C. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the dispersion relation of waves propagating in 1D nanostructures with initial axial stress. Based on a nonlocal elastic model incorporating with strain gradient, the governing equations for longitudinal and transverse waves in bars and beams have been derived, respectively. In this equation, two scale parameters are introduced to describe size effect. The phase and group velocities of wave propagation are obtained analytically, and the effects of initial axial loading on the wave speeds are analyzed. Examples are presented for flexural waves propagating in single-walled and double-walled carbon nanotubes. Waves are always present for tensile initial axial force, while they may not exist unless the compressive axial force fulfills a certain condition. In particular, the wave speeds are sensitive to initial force for lower frequencies and insensitive to it for higher frequencies. [Copyright &y& Elsevier]

Abstract: Different dispersion properties are imparted to nonradiative dielectric (NRD) waveguides by split ring resonator metamaterials. Both longitudinal section magnetic and longitudinal section electric modes are capable of propagating very slowly due to the metamaterial bianisotropic effects, and can even approach zero velocity under certain condition. Enhanced energy flow in the considered structure is also demonstrated. Finally, miniaturization of NRD waveguide based on these unusual properties is proposed. [Copyright &y& Elsevier]

Abstract: Colloidal TiO2 was prepared by hydrolyzing tetra-n-butyl titanate. Composite multilayer films of poly(sodium 4-styrenesulfonate) (PSS) and colloidal TiO2 particles were layer-by-layer assembled onto optic fibers and microscope glass slides. As the PSS/TiO2 film was deposited onto the end face of a glass fiber, the reflected optic intensity periodically oscillated as the bilayer number of the film increased. After a 24-bilayer film was coated onto the both sides of a glass slide, the transmittance at 850nm decreased more than 20%, which means that the film could serve the function as a reflection-enhancing coating. X-ray diffraction analysis and data of TEM electron diffraction analysis show that the colloidal TiO2 particles are mainly brookite nanocrystals and that the PSS/TiO2 films are polycrystalline films. Scratching experiments indicate that the composite films are of relatively high hardness. [Copyright &y& Elsevier]

Abstract: We analyze the propagation of piezoelectromagnetic waves guided by a plate of polarized ceramics between two ceramic half-spaces. An exact dispersion relation is obtained, which reduces to a few known elastic, electromagnetic, and quasistatic piezoelectric wave solutions in the literature as special cases. Numerical solutions to the equation that determines the dispersion relation show the existence of guided waves. The results are useful for acoustic wave and microwave devices. [Copyright &y& Elsevier]

Well-aligned carbon nanotube (CNT) array grown on Si-based nanoscale SiO2 islands was obtained by microwave plasma-enhanced chemical vapor deposition under low temperature of 520°C. Atomic force microscope observation and Raman spectroscopic analysis disclosed the formation of the CNTs. The SiO2 islands formed by excess anodization of Si-based Al film were found to be the growth points of the CNTs, which was confirmed by the C–V curves without charge characteristics. Position-controllable growth of CNTs was attempted on silicon substrate so as to explore significant applications in nanoelectronics and nanodevices. [Copyright &y& Elsevier]

Six-facets patterned sapphire substrates (A-PSS) are manufactured by wet-etching regular semispherical patterned sapphire substrates (r-PSS). The possible crystallographic planes of the etched planes on the semi-sphere pattern is the family of (1102) plane. Metalorganic Chemical Vapor Deposition (MOCVD) GaN epitaxial LED structure was grown on the c-plane sapphire wafer, r-PSS, and A-PSS, which were further processed as horizontal LED chips. Compared to LEDs on the flat c-plane sapphire, the light output power of LEDs on r-PSS and A-PSS is enhanced by 71% and 67%, respectively. The output power of the bare LEDs decreases after the white-light LED package. Remarkably, the output power of the white-light packaged LED on the A-PSS is larger than the white-light packaged LED on the r-PSS. The Monte Carlo ray tracing simulation shows that, before and after silicone-lens encapsulating, the LEDs on r-PSS and A-PSS emit more on the top surface. However, the sidewall emission power ratio of the LED on r-PSS decreases by 3.44% after silicone encapsulating. On the other hand, the sidewall emission power ratio of the LED on A-PSS increases by 1.06% after silicone encapsulating. Note that the emission light of LEDs out of the top surface travels a longer path in the silicone lens than the emission light out of the sidewalls. Hence, more re-extracted light out of the sidewall of LED on A-PSS would be the reason for the LED on A-PSS having a less package loss and the white-light package efficiency than the LED on r-PSS. In conclusion, the light radiation distribution pattern defined by the pattern morphology of A-PSS is the key for the better white-light package efficiency of the LED on A-PSS than that of the LED on r-PSS. • The patterned sapphire substrate morphology can alter the propagation direction of the light emission. • Monte Carlo ray tracing simulation shows the emission power of top surface and sidewall vary before and after lens package. • The emission light of LEDs out of the top surface travels a longer path in the phosphor layer than the sidewalls. • The light radiation distribution defined by the pattern morphology is the key for white-light package efficiency of LED. [ABSTRACT FROM AUTHOR]

Abstract: Ag coated ZnO/Al2O3 distributed Bragg reflectors (DBRs), which were fabricated by a modified filtered cathodic vacuum arc technique at room temperature, shown the formation of visible Tamm plasmon polaritons (TPP). By varying the thickness of Ag and top ZnO dielectric layer of the DBR, it can be verified that the excitation of dip at the stopband of the reflection spectrum is related to TPPs. As visible light was used to excite TPPs, the corresponding effective mass can be reduced to 1.3×10−5 of the free electron mass. [Copyright &y& Elsevier]

PbZrO 3 (PZ) antiferroelectric films and PbZr 0·52 Ti 0·48 O 3 (PZT) ferroelectric films are widely researched due to their significance as representative film materials. The article investigates the structure-performance relationship of PZT/PZ composite films with different PZ and PZT phase structures. PZT/PZ films with different PZ and PZT phase structures were fabricated on SiO 2 /Si substrates using the sol-gel method. The electrical properties of prepared films annealed at different temperatures were characterized and were compared at different annealing temperatures (550 °C, 600 °C, 620 °C, 650 °C). At the annealing temperature of 600 °C, it was observed that the presence of pyrochlore and perovskite phases in PZ makes the composite films high breakdown field strength (BDS) and moderate polarization (P m), enhancing the energy storage properties. However, when the annealing temperature exceeds 600 °C, it would have the opposite effect on the BDS and P m due to the increased pyrochlore and perovskite phase. The above analysis indicates that regulating the phase structure of PZ and PZT films is the effective approach to obtain high energy storage density capacitors. [ABSTRACT FROM AUTHOR]

Abstract Heavy metal pollution of paddy fields is of increasing concern due to the huge losses in rice yield that occur every year. Therefore, it is important to understand the microecological and physicochemical changes to paddy soil under varying cadmium (Cd) pollution levels. Here, we explore the bacterial community response to cadmium contamination of agricultural paddy soil. Our results reveal that high cadmium level sites displayed lower diversity indices than low cadmium level groups. In addition, total and available cadmium exhibited significant negative correlations with diversity indices. The dominant phyla that were observed in the paddy soil samples included Proteobacteria, Chloroflexi, Acidobacteria, Actinobacteria, Gemmatimonadetes, Verrucomicrobia, Thaumarchaeota, Firmicutes, and Nitrospirae. The results suggest that Actinobacteria are tolerant to cadmium, whereas Proteobacteria, Verrucomicrobia, and Nitrospirae are sensitive. According to the results of pCoA, bacterial communities were differentiated across cadmium pollution levels, suggesting that the active members of the microbial communities under cadmium stress were different from those in the control soils. In addition, Mantel tests showed that the overall bacterial community structure significantly correlated with total pH, available phosphorus (AP), organic matter (OM), total cadmium (TCd), and available cadmium (ACd). Highlights • Bacterial community in high Cd level groups displayed lower alpha diversity indices • TCd and ACd exhibited significant negative correlations with alpha diversity indices • Bacterial communities change significantly across cadmium pollution levels • The bacterial community was significantly correlated with pH, AP, OM, TCd and ACd [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to evaluate growth performance, whole-body composition, metabolism and digestion of Chinese soft-shelled turtle Pelodiscus sinensis fed with fish meal replacement by rice protein concentrate and squid paste supplementation diets. Three isonitrogenous and isoenergetic practical diets were formulated with the inclusion of 60% fishmeal (CT), 42% fish meal +18% rice protein concentrate (RP) and 42% fish meal +18% rice protein concentrate +1% squid paste (feeding attractant) (RPS), respectively. Microcapsule lysine was supplemented in RP and RPS diets to balance the amino acid profile. Turtles (initial weight 30.65 g) were fed thrice (6:00, 12:00 and 18:00) daily to apparent satiation. The results showed that growth performance in RP group showed no significant difference with that in CT group ( P  > .05). In addition, daily squid paste supplementation significantly improved growth performance, nutrients retention and relative feed intake ( P  < .05). Significantly increased activities of hepatic alanine aminotransferase as well as intestinal protease, γ-glutamyl transpeptidase, aminopeptidase N and carboxypeptidase A were also observed in RPS group ( P  < .05). The results suggested that rice protein concentrate could replace 18% dietary fish meal in Pelodiscus sinensis with microcapsule lysine supplementation. Besides, diet with squid paste inclusion could improve feed intake and growth performance of Pelodiscus sinensis . [ABSTRACT FROM AUTHOR]

A novel white-emitting ZnO@Eu 2 O 3 core/shell nanomaterials was synthesized by a green chemical method. The temperature and pressure dependence of the photoluminescence (PL) transition associated with the fundamental bandgap of ZnO@Eu 2 O 3 core/shell nanomaterials have been studied. The activation energy of ZnO@Eu 2 O 3 is 0.27 eV, which is higher than the commercial Y 2 O 3 : Eu 3+ . The near-bandedge emission is found to shift toward higher energy with applied pressure at a rate of 32.7 MeV/GPa with a small second-order term of −0.28 MeV/GPa 2 . The samples are very stable with white emission under 8 GPa, which are useful for white LEDs. [ABSTRACT FROM AUTHOR]

Metallic glasses with long-range disordered atomic structure have recently been attracted a great deal of research attention in catalytic field. Compared to crystalline materials, the metallic glasses present many advanced catalytic properties, yet the catalytic mechanism is not sufficiently understood. In this work, an Fe 78 Si 9 B 13 glassy ribbon manufactured by melt-spinning method was applied for the first time to compare its activation behavior on three peroxides, including hydrogen peroxide (H 2 O 2 ), persulfate (PS) and peroxymonosulfate (PMS). It was shown that Fe 78 Si 9 B 13 metallic glass had exceptionally high capability for activating these three common peroxides to produce reactive radicals ( OH and/or SO 4 • − ). The dominant species of H 2 O 2 in this work was demonstrated as hydroxyl radical ( OH) while the PS and PMS activation mainly generated sulfate radical (SO 4 • − ). The order of predominant radical generation rate by Fe 78 Si 9 B 13 activation under UV−vis irradiation was PS > H 2 O 2 > PMS. The relative contribution of sulfate radical (SO 4 • − ) in PS activation was 78% compared to 61% in PMS. All the peroxides activated by Fe 78 Si 9 B 13 metallic glass presented a radical generation rate at least ∼2 times higher than other iron-containing materials. Crystal violet (CV) dye was used to investigate the catalytic performance of Fe 78 Si 9 B 13 metallic glass for peroxides, which showed an ultrafast dye degradation rate with completely color removal within 15 min. The radical evolution mechanisms for H 2 O 2 , PS and PMS activation were also investigated. The change in surface morphology of ribbon after 5th run reused indicated that the inclusions of Si leading to formation of SiO 2 layer played an important role in the surface stability of ribbons. [ABSTRACT FROM AUTHOR]

A method for significantly enhancing the breakdown field strength and energy storage density of Pb 0.88 La 0.12 ZrO 3 (PLZ) films by inserting ZrO 2 (ZO) layer is provided. PLZ films with the inserting layer of ZrO 2 were deposited on SiO 2 /Si substrates buffered with LaNiO 3 films by the sol-gel method. The effect of ZrO 2 precursor solution concentration on structure and electrical properties was investigated. The results show that for the composite films with the sandwich structure, much improved electrical breakdown strength values of 1543 kV/cm and maximum polarization values of 83.5 μC/cm2 were obtained, which are 141% and 40% higher than pure PLZ films, respectively. With the combination of a high breakdown field strength and a large maximum polarization value, the film has an energy storage density of up to 32.6 J/cm3 when ZrO 2 precursor solution concentration is 0.1 mol/L. Our results show that the design of PLZ/ZO/PLZ composite films is an effective way to obtain high energy storage density capacitors. • The composite films exhibited high electrical breakdown strength value. • The energy storage density of PLZ/ZO/PLZ composite film is raise to 32.6 J/cm3. • Inserting ZrO2 layer is a good way to improve the energy storage of PLZ films. [ABSTRACT FROM AUTHOR]

In this work, a nano-cavity patterned sapphire substrate (nc-PSS) is fabricated by using a self-formed meshed Pt thin film on a c-plane sapphire substrate. The light output power of a GaN-based light emitting diode on the nc-PSS is 45% greater than that of a control light emitting diode that was prepared on a flat c-plane sapphire substrate (f-SS) wafer. The GaN-based light emitting diode that was prepared on the nc-PSS exhibited much less drooping than a GaN-based light-emitting diode that was prepared on a commercial semi-sphere patterned sapphire substrate (r-PSS), mainly because the voids that formed at the cavities at the GaN/nc-PSS interface buffered the stress in the GaN epi-layers that was imposed by the sapphire substrate. [ABSTRACT FROM AUTHOR]

The couple-stress elasticity is applied to study an anti-plane shear crack at the interface between two bonded dissimilar elastic media with initial stresses. First, the deviatoric couple stress tensor is proven. The governing equation alongside associated boundary conditions is derived. Using the eigenfunction expansion method, the singularity index is determined. Then, the Fourier transform is employed to convert the mode-III interface crack problem to a hypersingular integral equation. Using the Chebyshev series method, the resulting hypersingular integral equation is numerically solved. The crack-tearing-displacement, couple-/force-stress intensity factors, and energy release rate are evaluated to reveal the influence of the intrinsic characteristic lengths, couple-stress material constants, and initial stresses. • Mode-III interface crack in a bi-material with couple stress and initial stress is studied. • Antiplane shear stresses near the crack tips have an r − 3 / 2 singularity. • Couple stresses near the crack tips have an r − 1 / 2 singularity. • The strains at the crack tips vanish and are no longer singular. • Effects of characteristic lengths and initial stresses on fracture parameters are analyzed. [ABSTRACT FROM AUTHOR]

The structure and electrical properties of Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 -xBiFeO 3 ceramics (x = 0 %, 3 %, 8 % and 15 %) were investigated. The prepared samples show perovskite structure, and there is no detected second phase. The grain size of all ceramic samples doped with BiFeO 3 is significantly reduced. The doped samples have obvious relaxation characteristics, showing obvious dispersion phase transition and frequency dispersion. The P-E curve becomes thin with the increase of doping amount, but it changes reversely under higher doping content. For sample with the doping amount of 8 %, a thin and long hysteresis loop is observed, and the sample has the best energy storage characteristics with the energy storage density of 0.57 J/cm3 and the energy storage efficiency of 91.3 %. This study provides a method to improve the energy storage density and efficiency of BCZT ceramics. • The prepared samples show perovskite structure, and there is no detected second phase. • Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 -8 %BiFeO 3 has the energy storage density of 0.57 J/cm3. • Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 -8 %BiFeO 3 has the energy storage efficiency of 91.3 %. • This study provides a method to improve the energy storage performance of BCZT ceramics. [ABSTRACT FROM AUTHOR]

• The size-dependent thermoelastic damping of a circular microplate is determined. • Fractional dual-phase-lag (DPL) incorporating the couple stress theory is put forward. • An analytical expression for thermoelastic damping of a circular microplate is given. • Effects of the fractional order, relaxation time, and characteristic length on the inverse quality factor are analyzed. In the present work, thermoelastic damping in a micro-resonator operating in vacuum as a vibrating size-dependent circular thin plate is studied. To better describe the heat conduction process, a generalized thermoelasticity theory of fractional dual-phase-lag (DPL) incorporating the couple stress theory is put forward to capture the experimentally observed small-scale effect of thermoelastic dissipation. The complex frequency of the micro-plate is obtained through Laplace transform technique. Finally, Lifshitz and Roukes's complex frequency method is employed to derive an analytical expression for thermoelastic damping. The influences of the parameters including fractional order, phase-lag time, and internal characteristic length on the inverse quality factor Q − 1 are analyzed. The obtained results show that the influences of these parameters on thermoelastic damping are pronounced. These results are helpful to the design of micro-/nano-resonators with high-performance. [ABSTRACT FROM AUTHOR]

Faraday shield is a thin copper structure with a large number of slits which is usually used in inductive coupled plasma (ICP) sources. RF power is coupled into the plasma through these slits, therefore Faraday shield plays an important role in ICP discharge. However, due to the complex structure of the Faraday shield, the resulted electromagnetic field is quite hard to evaluate. In this paper, a 2D model is proposed on the assumption that the Faraday shield is sufficiently long and the RF coil is uniformly distributed, and the copper is considered as ideal conductor. Under these conditions, the magnetic field inside the source is uniform with only the axial component, while the electric field can be decomposed into a vortex field generated by changing magnetic field together with a gradient field generated by electric charge accumulated on the Faraday shield surface, which can be easily found by solving Laplace's equation. The motion of the electrons in the electromagnetic field is investigated and the results show that the electrons will oscillate along the radial direction when taking no account of collision. This interesting result brings insight into how the RF power couples into the plasma. [ABSTRACT FROM AUTHOR]

A new detection system with high detection efficiency and low detection threshold has been developed for charged-particle decay studies, including β-delayed proton, α decay or direct proton emission from proton-rich nuclei. The performance was evaluated by using the β-delayed proton emitter 24 Si produced by projectile fragmentation at the First Radioactive Ion Beam Line in Lanzhou. Under a continuous-beam mode, the isotopes of interest were implanted into two double-sided silicon strip detectors, where the subsequent decays were measured and correlated to the preceding implantations by using position and time information. The system allows us to measure protons with energies down to about 200 keV without obvious β background in the proton spectrum. Further application of the detection system can be extended to the measurements of β-delayed proton decay and the direct proton emission of more exotic proton-rich nuclei. [ABSTRACT FROM AUTHOR]

Aims Several studies have evaluated the association between smoking and p53 mutation in oesophageal squamous cell carcinoma (ESCC), but the conclusions are inconsistent. The aim of the present study was to carry out a meta-analysis evaluating the relationship between smoking and p53 mutation in patients with ESCC. Materials and methods Eligible studies were identified through searches in PubMed and EMBASE. The odds ratio with 95% confidence interval was used to assess the association. In total, 20 studies were identified that met the selection criteria; these studies were analysed using STATA 12.0 software. Results The 20 studies identified comprised 1524 ESCC patients, of whom 72.97% were smokers and 27.03% were non-smokers. The pooled odds ratio of p53 mutation in ESCC for any cigarette smoking versus no smoking was 1.28 (95% confidence interval = 0.88–1.88). The estimated odds ratios were 1.06 (95% confidence interval = 0.56–2.00, based on five studies, 129 light smokers and 70 non-smokers) for light smoking and 2.01 (95% confidence interval = 1.12–3.60, based on five studies, 223 heavy smokers and 73 non-smokers) for heavy smoking. Conclusion The results of our meta-analysis indicate an overall positive relationship between heavy smoking and p53 mutation in ESCC. Heavy smokers with ESCC have a higher risk for p53 mutation than non-smokers. Large-scale clinical studies are still needed to draw a more precise conclusion. [ABSTRACT FROM AUTHOR]

Highlights: [•] It combined the advantages of existing wetting procedures; soil samples and dispersing agents are de-aerated synchronously over a short duration. [•] It reduced the variability of wet aggregate stability (WAS) measurements and provided the most reliable and accurate description for of WAS. [•] This novel technique was easy to conduct and without a large time requirement, and can be applicable to a large range of soils with different soil organic matter. [Copyright &y& Elsevier]

Zn1−x Cd x O (x=0.2) thin films were deposited on glass substrates at different substrate temperatures (Ts) by the direct current (dc) reactive magnetron sputtering method. The influence of substrate temperature on structural and optical properties was investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), optical absorption spectra and Raman scattering in detail. Results indicated that all the obtained Zn1−x Cd x O (x=0.2) thin films were of highly (002)-preferred orientation and possessing the hexagonal wurtzite structure of pure ZnO, the crystalline quality first was improved and then deteriorated as the Ts increased up from 25°C to 600°C, when Ts is 550°C, the film had the best crystalline quality. Meanwhile, the optical band gap of Zn1−x Cd x O films was tuned from 2.728 to 2.782eV, which was attributed to the variation of the compressive stress and the Cd re-evaporation in the films. In addition, the residual stress and defects of films were evaluated from Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Highlights: [•] The p-type ZnO thin films with low resistivity are obtained by P–N codoping method. [•] The p-type character is identified by rectification character of ZnO homojunction. [•] The electrical properties are extremely sensitive to the annealing temperature. [•] The p-type ZnO with good properties is obtained at middle annealing temperature. [•] The chemical states of P and N are identified by XPS analysis. [Copyright &y& Elsevier]

Abstract: High spin states of 114In were investigated via the reaction at beams energy of 26 and 28 MeV. The newly observed magnetic dipole bands of 114In in the experiment have been investigated employing the self-consistent tilted axis cranking relativistic mean-field theory based on a point-coupling interaction. A large backbend in the yrast band has been reproduced by the theory based on configuration involving alignment of a pair of positive-parity neutrons. According to the experimental characteristics and theoretical calculations, the positive-parity dipole band has been assigned as a magnetic rotation band. In addition, the experimental results are also compared with a semiclassical geometric model that employs effective interactions between the proton holes and neutrons as an alternate interpretation for the shears mechanism. [Copyright &y& Elsevier]

Abstract: High purity MgO nanopowders were pressed into pellets and annealed in air from 100 to 1400°C. Variation of the microstructures was investigated by X-ray diffraction and positron annihilation spectroscopy. Annealing induces an increase in the MgO grain size from 27 to 60nm with temperature increasing up to 1400°C. Positron annihilation measurements reveal vacancy defects including Mg vacancies, vacancy clusters, microvoids and large pores in the grain boundary region. Rapid recovery of Mg monovacancies and vacancy clusters was observed after annealing above 1200°C. Room temperature ferromagnetism was observed for MgO nanocrystals annealed at 100, 700, and 1000°C. However, after 1400°C annealing, MgO nanocrystals turn into diamagnetic. Our results suggest that the room temperature ferromagnetism in MgO nanocrystals might originate from the interfacial defects. [Copyright &y& Elsevier]

Abstract: Crack problems in 2-D and 3-D linear viscoelastic media are numerically investigated using the enriched finite element method (enriched FEM). In the same spirit as for the enriched elements, the viscoelastic crack-tip asymptotic displacement field is obtained by using the viscoelastic–elastic correspondence principle and is transformed into the polynomial displacement field of regular elements. Thereby, the time-dependent unknowns in the asymptotic displacement field related to the crack strain energy release rate are introduced as the additional degree of freedoms (DOFs) of enriched elements. With these treatments, the incremental enriched FEM formulations in time domain are derived according to the Boltzmann superposition principle. The present method shows that the time-dependent strain energy release rate can be easily obtained from the extra DOFs. Several illustrative examples are given and good agreement between the present results and those from analytical and other numerical methods is confirmed. The method developed in this paper is capable of solving crack problems in viscoelastic media with complicated geometry, loading and constraint conditions. [Copyright &y& Elsevier]

Abstract: Electronic structure, spontaneous polarization, piezoelectric, and nonlinear optical properties of the LiNbO3(LN)-type ZnGeO3 have been investigated based on the density functional theory. The electronic structure reveals that the LN and corundum-type ZnGeO3 are both direct-band-gap semiconductors. The results reveal that the LN-type ZnGeO3 is ferroelectric with a large spontaneous polarization of 63.59μC/cm2. Although the LN-type ZnGeO3 and LiNbO3 belong to the same point group 3m, their piezoelectric and nonlinear optical susceptibilities show the different tensor forms. According to the predictive results, the large piezoelectric constants and NLO susceptibilities reveal that the LN-type ZnGenO3 would be a candidate for a high-performance lead-free piezoelectric and nonlinear optical crystal, which will avoid the environmental toxicity problem of the lead-based materials. [Copyright &y& Elsevier]

Abstract: Soil quality and crop yield improvements through use of conservation tillage have been widely documented in the world. As the “bread basket” of the northern region of Northeast China, located at 47°N, China''s arable Black soils are consistently and intensively tilled and have been seriously degraded and eroded. Wide spread adoption of conservation tillage in this area will occur only if acceptable yields are demonstrated with its use. In this study, corn (Zea mays L.) and soybean (Glycine max Merril.) yield with no-till (NT), reduced-till (RT) and conventional tillage (CT) were compared from 2004 to 2010 on two separate areas, sloping and nearly flat farmland. Soybean yields increased significantly and, in contrast, corn yields decreased significantly under NT compared to CT. The average increase of soybean yield was 8.9% on the flat farmland and 13.8% on sloping farmland. The average corn yield decrease was 28.4% on the flat farmland and 15.7% on sloping farmland. A significant increase in soil moisture and decrease in soil temperature was found in the early growing season for NT compared to RT and CT. NT decreased surface runoff and increased soil water storage, which boosted soybean yield on the sloping farmland. Our study demonstrated NT was an effective and beneficial soil tillage practice and should be widely applied for soybean production in the northern region of Northeast China, where the sloping farmlands are mainly distributed with soybean as the main crop. [Copyright &y& Elsevier]

Abstract: Three commercially available standard anion resins (ARs) produced quality sulfate-free reclaimed water containing low levels of phosphorus (P) (∼0.10mgL−1), nitrate (∼0.20mgL−1) and dissolved organic matters (DOMs) (∼0.68mgL−1) from the actual secondary effluent of anaerobic/anoxic/aerobic process for municipal wastewater (MW-SE, containing 67mgsulfateL−1, 1.30mg P L−1, 8.50mgnitrateL−1 and 3.30mgDOMsL−1) in the fixed-bed column experiments. The influent DOM levels (1.2–9.4mgL−1) had minor influences on nutrient removal performance. The stable adsorption efficiencies of ≥89, ≥95 and ≥71% and elution efficiencies of ≥99, ≥92 and ≥54% were achieved for phosphate, nitrate and DOMs in 5 successive adsorption–regeneration cycles. The standard ARs should be combined with the anoxic/aerobic biodenitrification process to better recover P resources from MW and achieve the highest nitrogen and P removal. With chloride salt fertilizers (e.g. NH4Cl or KCl) as regenerants, most of the P and nitrate in MW-SE can be concentrated into spent regenerant that can be easily and fully converted to a new nitrogen phosphorus mixed fertilizer, which will finally solve the disposal problem of spent brines. [Copyright &y& Elsevier]

Abstract: High-power continuous wave green radiation has been generated by means of type-II phase-matched frequency doubling in a KTP crystal located in a simple linear cavity incorporating a diode side-pumped Nd:YAG laser module. The cavity was designed to make the fundamental beam radius at the KTP crystal smaller than that at the gain medium, as is required for obtaining large mode volume in Nd:YAG crystal and realizing efficient CW intracavity frequency doubling. Output power of 51.2W is obtained in the experiment with a diode-to-green optical conversion efficiency of 10.3%. The M2-parameters of the laser are measured at different output powers. For the output power of about 47W, the power fluctuation is measured less than 1%. The experimental results show that the continuous wave green laser system using this simple linear cavity offers good laser performance and output stability. [Copyright &y& Elsevier]

A semi-spherical pattern can be converted to a triangular pyramid comprising three r-planes using chemical wet etching with a mixture of sulfuric and phosphoric acids. The apex Al atom on the triangular pyramid with numerous dangling bonds can be subject to etching with prolonged exposure. After removing the apex Al atoms, Al atoms underneath the r-plane can be readily etched and low incline-angle, side-facet planes are developed. The concentrations of SO 4 2- and PO 4 3- ions in the mixed etching solution greatly affect the etching rate on the patterns on the sapphire surface. The SO 4 2- and PO 4 3- etchant ions in the etching solution will react with the etching site (surface Al atoms) and form Al 2 (SO 4) 3 and AlPO 4. The molar ratios of the reactants (surface Al etching sites and acid molecules) are different. Given the size of the SO 4 2- radicals (the average bond length of the sulfate ion is 1.49 Å), the other surface Al atoms next to the Al atoms engaging with the SO 4 2- radicals cannot be close to any free SO 4 2- radicals in the etching solution. This effect is called the "screening effect" or "spatial barrier effect." For forming AlPO 4 , one PO 4 3- ion can bond with one etching Al site without being limited by the spatial screening effect. There is no spatial screening effect for the phosphoric acid etching of a sapphire surface. Thus, phosphoric acid would have a higher etching rate of a sapphire surface than sulfuric acid. In this study, the bottom of the triangular pyramid is not an equilateral triangle. Instead, the sides of the bottom triangular of the triangular pyramid are curved. The availability of etching Al sites on the etching side-facet surface and ridges of the triangular pyramid can explain the curved sides of the bottom triangle of the triangular pyramid. • Without screening effect, PO 4 3- can bond with an etching Al site without limited. • Al atoms engaging with SO 4 2- radicals screen another Al atom. • No screening spatial barrier occur on the ridge of the triangular pyramid pattern. [ABSTRACT FROM AUTHOR]

We employ the method of laser interference crystallization carried out by using a phase-shifting grating mask (PSGM) to fabricate nanocrystal Si with a two-dimensional (2D) patterned distribution within a 10 nm thick a-Si:H single layer grown on a SiO2/Si or fused quartz substrate by the plasma-enhanced chemical vapor deposition technique. The results of atomic force microscopy, cross-section transmission electron microscopy and high resolution transmission electron microscopy show that Si nano-crystallites are formed and selectively located in the discal regions within the initial a-Si:H layer, which are patterned with the same 2D periodicity of 2.0 μm as the PSGM. The diameter of each discal region is about 250 nm and the height is about the same as the thickness of a-Si:H layers. These results demonstrate that the present method is promising for the fabrication of various patterned nc-Si arrays for device applications simply by changing the geometry of the mask. [Copyright &y& Elsevier]

TiO2 ceramics doped with 0.75 mol% Ca and 2.5 mol% Ta were sintered at different temperatures ranging from 1300 to 1450°C. The effects of sintering temperature on the microstructure, nonlinear electrical behavior, and dielectric properties of the ceramics were studied. The sample sintered at 1300°C exhibits the highest nonlinear coefficient (5.5) and a comparatively lower relative dielectric constant. [Copyright &y& Elsevier]