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In this study, the influence of the deposit thickness of SiO2 insulation layers on the magnetic behaviors of Fe-Si@SiO2 soft magnetic composites (SMCs) was investigated by adjusting the deposition temperatures (550 °C, 600 °C, 650 °C, 700 °C, and 750 °C) during the fluidized chemical vapor deposition (CVD) process. The microstructures of Fe-Si@SiO2 composite particles and SMCs were also studied systematically. After combining the magnetic behavior results, the regression relationships between the magnetic behaviors of Fe-Si@SiO2 SMCs and the SiO2 insulation layer thickness distribution were obtained. It was found that the thickness, deposition rate, and heterogeneity of the SiO2 insulation layer were severely affected by the deposition temperature, resulting in a remarkable variation of the magnetic properties of Fe-Si@SiO2 SMCs. An increasing SiO2 insulation layer thickness had positive effects on the electrical resistivity and the eddy-current loss, almost no effects on the magnetic moment, and negative effects on the saturation magnetization of Fe-Si@SiO2 SMCs. Hence, these results will provide a new insight to examine the growth mechanism of the SiO2 insulation layer and magnetic performance of SMCs, which will be advantageous for the future design of efficient Fe-Si magnets.

A novel emulsified photoinitiator (named as OP10-IPDI-2959) was prepared by the reaction of isophorone diisocyanate (IPDI) with 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (Ir-2959) and nonylphenol polyoxyethylene ether (OP-10). The structure of OP10-IPDI-2959 was characterized by FT-IR, 1H NMR, UV–vis and high-resolution mass spectrometry. The photochemical behavior of OP10-IPDI-2959 was investigated through the photolysis and polymerization of neopentyl glycol diacrylate (NPGDA), mixture of epoxy acrylate resin and 1,6-hexanediol diacrylate (HDDA). Under irradiation of UV light, the OP10-IPDI-2959 has similar photochemical properties with the Ir-2959. Combined with benzophenone, the photoinitiated rate of OP10-IPDI-2959 is higher than that of Ir-2959. The polyoxyethylene fragment of OP10-IPDI-2959 is not only an alternative to toxic amine as hydrogen donor, but also a hydrophilic unit for interface between oil and water. The OP10-IPDI-2959 can effectively emulsify the epoxy acrylate resin and 1,6-hexanediol diacrylate mixture to form low viscosity emulsion. Compared with Ir-2959, OP10-IPDI-2959 has good photoinitiation activity, lower migration and good water emulsification performance.

The hazards associated with the extraction of ores and the construction of underground geoengineering structures should be mitigated to prevent the loss of human life. Microseismic monitoring (MM) has been used extensively in underground engineering around the world to assess the condition of underground structures and to improve personnel safety. However, MM cannot be currently used as a real-time early warning system because arrival detection still requires manual processing. Although studies have forwarded automated algorithms to perform this task, they are far less accurate than a human expert and therefore provide inaccurate source locations. In this study, we propose a workflow to specifically obtain the state-of-the-art performance of arrival detection. First, to avoid severe class-imbalance problems and speed up convergence in training, a new label form is proposed. We then propose an innovative self-attention mechanism in deep learning to efficiently model distant correlation (“segmentation-integration self-attention”). This new self-attention mechanism can effectively encode the distant inner dependencies by processing signals in several segments and by building correlations between the corresponding descriptors for the segments. Additionally, a new neural network architecture (“extractor-encoder-generator”) for automated arrival picking is proposed based on the above self-attention. This architecture extracts functional features of the signals, models correlations by an attention-related sublayer and generates a score map defining the confidence of the first break. The combination of the above technology is referred to as the “auto-detection” network. The new architecture outperforms all other algorithms by a considerable margin, provides a similar accuracy to that of a human expert, and is well balanced in terms of inference speed and accuracy. The auto-detection network allows for a practical and automated MM technique that can be used to provide an accurate real-time early warning system.

A new hybrid heterostructure of p-type copper phthalocyanine (CuPc) and n-type porous GaN (PGaN) has been fabricated by electrophoretic deposition. The influence of CuPc concentration, electric field intensity, and deposition time on the growth of CuPc film has been explored. The as-prepared CuPc films are made of numerous nanorods. The X-ray diffraction (XRD) spectra revealed that the CuPc films are the β phase and amorphous type on pristine and porous GaN, respectively. Moreover, the prototype devices were fabricated on the basis of the CuPc/PGaN heterostructures. The devices exhibited excellent photodetector performance under ultraviolet (UV) light illumination.

The well-defined single-crystalline microwires of a solid-emissive organic functional molecule, 2-(anthracen-9-yl)-4, 5-diphenyl-1H-imidozole (ADPI) were successfully prepared by a facile solution process without the use of surfactant or additional templates. In addition, the optical loss coefficient is as low as 0.1 dB μm −1 for the as-prepared ADPI microwires, which is lower than most previous reported organic optical waveguides. Meanwhile, these microwires also show optically uniaxial properties as demonstrated by the linearly polarized emission, providing potentially orientation-sensitive applications as optical waveguides with low optical loss.

We developed an one-step and two-step metal-assisted chemical etching method to produce self-organized GaN nanowire arrays. In one-step approach, GaN nanowire arrays are synthesized uniformly on GaN thin film surface. However, in a two-step etching processes, GaN nanowires are formed only in metal uncovered regions, and GaN regions with metal-covering show nano-porous sidewalls. We propose that nanowires and porous nanostructures are tuned by sufficient and limited etch rate, respectively. PL spectra shows a red-shift of band edge emission in GaN nanostructures. The formation mechanism of nanowires was illustrated by two separated electrochemical reactions occur simultaneously. The function of metals and UV light was illustrated by the scheme of potential relationship between energy bands in Si, GaN and standard hydrogen electrode potential of solution and metals.

In the process of microelectronic device fabrication, the oxygen atom plays a double role. It oxidizes Si producing the SiO2 layer. Moreover, it oxidizes the metal electrodes causing failures and enters the semiconductor acting as an impurity recombination center. This phenomenon is closely related to the oxygen diffusion in the material surface. Although a textured material surface is frequently used, the oxygen diffusion inside this surface is rarely studied. Studies are available only for planar material surfaces. In this work, monocrystalline Si slices with a pyramidal textured surface and a series of Cu films, which were deposited onto this substrate, were thermally oxidized. The oxygen diffusion in such textured surfaces was quantitatively analyzed via transmission electron microscopy. The oxygen distribution and the variation in the oxygen:cation atomic concentration ratio as a function of the oxide thickness were obtained. Thus, suboxide diffusion layers of SiOx and CuOx were found for the surfaces. In addition, the oxidation rate of the textured material surface was significantly reduced due to its lower oxygen partial pressure when compared to a planar surface. These results can be used to control the oxide thickness, to resist the electrode oxidation, and to reduce the concentration of oxygen recombination centers when using a textured material surface for optoelectronic devices.

Steel fibres were used to reinforce the layered targets with surface-to-surface combination. The two- and three-layer metal targets with a total thickness of 5 mm were fabricated by explosive welding. The damage mechanism and the anti-penetration performance of the targets were studied experimentally and numerically using the LS-DYNA 3D finite element code. The effects of layer number and fibre spacing density on the anti-penetration performance were discussed. The results show that the failure modes of the steel front plate were shearing and plugging, and that the failure mode of the aluminium rear plate was ductile prolonging deformation when the tied interface failed by tension (or shearing and plugging when the interface remained connected) for the two-layer target. For the three-layer target, the failure modes of the steel front plate and the aluminium middle plate were shearing and plugging, while the steel rear plate failed by ductile prolonging deformation. At the same time, the steel-fibres failed by bending and tensile deformation. The anti-penetration performance of the three-layer composite targets was better compared with the performance of the two-layer targets when the areal density and fibre spacing density were equal. The reinforced fibres will improve the anti-penetration performance of the targets, and the ballistic resistance decreased with an increase in the fibre spacing distance.

We develop a facile approach for the one-step growth of ultralong and high-quality NiOEP nanowires in a large area, through a solvent-induced self-assembly method without using any structure directing agents. The size of the nanowires can be controlled by changing the composites of solvent mixtures. Being assembled in visible-light sensors, these nanowires exhibit a fast, reversible, and stable response. The highest Ion/Ioff ratio and photoresponsivity of photodiodes could reach 681 and 10.1 mA W−1, respectively, which could be attributed to the perfect single crystal quality, large surface to volume ratio, and fewer recombination barriers within the nanostructures. The facile fabrication and good photoresponse make NiOEP nanowires promising in optoelectronic applications.

The Debye temperature of wurtzite aluminum nitride (AlN) was determined by the Rietveld refinement method based on the room-temperature X-ray powder diffraction data. The refined lattice parameters area = 3.11139(1) Å,c = 4.978 43(3) Å; the refined positional parameter for N isz = 0.384 59(33) Å; and the refined temperature factors of Al and N were 0.442(12) Å2and 0.559(33) Å2, respectively. Using this refined temperature factor, the Debye temperature was evaluated as 971 K through the Debye approximation.

We aimed to investigate the role of 4 single nucleotide polymorphisms of the xeroderma pigmentosum complementation group F (XPF) gene (rs3136038, rs1799798, rs1800067, and rs2276466) in glioma, and the roles of gene-gene interactions in the risk of developing this type of cancer. We collected samples from 225 glioma cases and 262 controls and genotyped the rs3136038, rs1799798, rs1800067, and rs2276466 polymorphisms using a 384-well plate format with the Sequenom MassARRAY platform. Individuals carrying the rs1800067 GG genotype were more likely to have an increased risk of glioma when compared with carriers of the A/A genotype in a co-dominant model, with an odds ratio (OR) [95% confidence interval (CI)] of 2.85 (1.14-7.76). However, we did not find an association with increased risk of glioma for the polymorphisms rs3136038, rs1799798, and rs2276466 in XPF. The combination genotype of the rs1800067 G allele and the rs2276466 G allele was associated with a moderate risk of glioma (OR = 1.71, 95%CI = 1.02-2.87). Our study suggests that the rs1800067 genetic variant of XPF functions in the development of glioma.

In this article, we consider a fractional order backward heat conduction problem in two-dimensional space which is associated with a deblurring problem. The problem is seriously ill-posed. We propose an optimal regularization method to solve the problem in the presence of noisy data, and obtain the optimal stability error estimation. A deblurring and denoising experiment shows that the optimal method is comparable with the Tikhonov method.

The growth of AlN crystals by PVT method was investigated using TaC crucible in the temperature range of 2250-2350 degrees C. AlN boules with 30 mm in diameter were successfully grown on the crucible lid by self-seeded growth. The AlN boules consist of the spontaneously nucleated AlN single crystal grains with the {10 (1) over bar0} natural crystalline face. The fast growth rate of more than 1 mm/h was achieved. AlN crystals grown on (11 (2) over bar0)-, (10 (1) over bar0)-, and (0001)-face AlN seeds were investigated. Different experimental phenomena have been observed under particular condition. The crystal grown on (11 (2) over bar0)-face seed has different natural crystalline face from the seed. For the crystal grown on (10 (1) over bar0) or (0001) seed, the crystal natural crystalline face is same as the crystallographic orientation of the seed. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Polar and non-polar ZnMgO were synthesized on different crystallographic planes (C-, R- and M-planes) of sapphire (Al 2 O 3 ) substrates by metal organic chemical vapor deposition, respectively. Under the same experimental condition, polar ZnMgO nanorods were obtained on C-Al 2 O 3 substrate whereas non-polar ZnMgO thin films were obtained on R- and M-Al 2 O 3 substrates. The surface morphology was significantly influenced by the competition of the preferable growth directions on different sapphire substrates. On C-Al 2 O 3 substrate, ZnMgO nanorods were vertically well-aligned with typical lengths in the range 330–360 nm. On R- and M-Al 2 O 3 substrates, however, ZnMgO thin films with flat surfaces were obtained, whose thickness were 150 and 20 nm, respectively. Under the same condition, the C-ZnMgO deposited on C-Al 2 O 3 substrate has the maximum growth velocity (11 nm/nim), followed by A-ZnMgO deposited on R-Al 2 O 3 substrate (5 nm/min), and the M-ZnMgO deposited on M-Al 2 O 3 substrate has the minimum one (0.67 nm/min). The Near-Band-Edge (NBE) emission in Photoluminescence (PL) spectra shows a clear blueshift and a slight broadening compared with that of pure ZnO samples, which suggest that the Mg content has successfully incorporated into ZnO. The different energy blueshifts (67 meV and 98 meV) of the NBE emission demonstrate that A-ZnMgO deposited on R-Al 2 O 3 substrate has higher Mg incorporation efficiency than C-ZnMgO on C-Al 2 O 3 substrate.

The acid-base vapors/light double responsive dye-infiltrated SiO2 inverse opal photonic crystals (PCs) were fabricated by sacrificial template method and a subsequent infiltration of spiropyran derivative dye molecules. The fluorescence of ring-open dye molecules infiltrated in PCs can be switched on/off based on different fluorescence properties of spiropyran dye under stimuli of acid-base vapors or light, when PCs with suitable stopband were selected. The fluorescence switch behavior based on PCs has potential applications in data storage, color displays, chemical and biological sensors.

We present industrialized bifacial solar cells on large area (149 cm2) 2 cm CZ monocrystalline silicon wafers processed with industrially relevant techniques such as liquid source BBr3 and POCl3 open-tube furnace diffusions, plasma enhanced chemical vapor deposition (PECVD) SiNx deposition, and screen printed contacts. The fundamental analysis of the paste using at boron-diffused surface and the bifacial solar cell firing cycle has been investigated. The resulting solar cells have front and rear efficiencies of 16.6 and 12.8%, respectively. The ratio of the rear JSC to front JSC is 76.8%. It increases the bifacial power by 15.4% over a conventional solar cell at 20% of 1-sun rear illumination, which equals to the power of a conventional solar cell with 19.2% efficiency. We also present a bifacial glass–glass photovoltaic (PV) module with 30 bifacial cells with the electrical characteristics. Copyright © 2010 John Wiley & Sons, Ltd.

The magnetotransport properties of a nominally undoped InGaN thin film grown by metal-organic chemical vapor deposition were investigated. Resistivity was measured under a magnetic field up to 5 T over the temperature range of 3 to 298 K. The film exhibits a negative magnetoresistance at low temperatures. Its magnitude decreases with increasing temperature, and turns to be positive for temperatures above 100 K. The negative component was described by a model proposed by Khosla and Fischer for spin scattering of carriers in an impurity band. The positive part was attributed to the effect of Lorentz force on the carrier motion. Agreement between the model and the data is presented.

The crystalline, surface, and optical properties of the (1 0 1¯ 3¯) semipolar GaN directly grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE) were investigated. It was found that the increase of V/III ratio led to high quality (1 0 1¯ 3¯) oriented GaN epilayers with a morphology that may have been produced by step-flow growth and with minor evidence of anisotropic crystalline structure. After etching in the mixed acids, the inclined pyramids dominated the GaN surface with a density of 2×105 cm−2, revealing the N-polarity characteristic. In the low-temperature PL spectra, weak BSF-related emission at 3.44 eV could be observed as a shoulder of donor-bound exciton lines for the epilayer at high V/III ratio, which was indicative of obvious reduction of BSFs density. In comparison with other defect related emissions, a different quenching behavior was found for the 3.29 eV emission, characterized by the temperature-dependent PL measurement.

Rheoforming is becoming the choice of the casting industry which relies on the semi-solid slurry for high integrity structural parts. The potential of rheoforming with LSPSF (Low superheat pouring with a shear field) for aluminum alloys was investigated in the present work. High quality semi-solid slurries of a series of aluminum alloys were manufactured by LSPSF process, such as casting alloy A356, high strength alloy 201, secondary die casting alloy A380 and wrought alloy 2024, 6082 and 7075, in which the primary α-Al presented spherical, small and homogeneous distribution, especially with zero-entrapped liquid. Applications of LSPSF in high pressure die casting process and squeeze casting process were presented. Results showed that LSPSF rheoforming could improve microstructures and increase mechanical properties.

The influence of Cu substitution for Mn on mag- netic properties and magnetic entropy change has been investigated in Heusler alloys, Ni50Mn35−xCuxSn15 (x = 2, 5 and 10). With increasing Cu content from x = 2 to x = 5, the martensitic transition temperature, TM , de- creases from 220 K to 120 K. Further increasing Cu up to x = 10 results in the disappearance of TM .F or samples Ni50Mn33Cu2Sn15 and Ni50Mn30Cu5Sn15, both martensitic and austenitic states exhibit ferromagnetic characteristics, but the magnetization of martensitic phase is notably lower than that of austenitic phase. The magnetization differ- ence, �M , across the martensitic transition leads to a con- siderably large Zeeman energy, μ0�M · H , which drives a field-induced metamagnetic transition. Associated with the metamagnetic behavior, a large positive magnetic en- tropy changeS takes place around TM . For the sample Ni50Mn33Cu2Sn15 ,� S reaches 13.5 J/kg·K under a mag- netic field change from 0 to 5 T.

Ghrelin, the endogenous ligand for the growth hormone secretagogue receptor (GHS-R), has been found in the gastrointestinal tract of many vertebrates, but little is known about its distribution in the gastrointestinal tract of African ostrich chicks. In the present study, the distribution, morphological characteristics, and developmental changes of ghrelin-producing cells in the gastrointestinal tract of African ostrich chicks were investigated using immunohistochemistry. Ghrelin-immunopositive (ghrelin-ip) cells were found to be localized in the mucous membrane of the entire gastrointestinal tract, but not in the myenteric plexus. The greatest number of ghrelin-ip cells was found in the proventriculus, and the ghrelin-ip cell density gradually decreased from the proventriculus to the rectum. Interestingly, from postnatal day 1 to day 45 in the proventriculus, and from postnatal day 1 to day 90 in the gizzard and small intestine, there was a steady increase in the number of ghrelin-ip cells. By day 45 in the proventriculus and day 90 in the gizzard and small intestine, the number of cells reached a plateau and remained steady. These results clearly demonstrate that ghrelin-ip cells exist and the number of ghrelin-ip cells increases with age in the African ostrich gastrointestinal tract from postnatal day 1 to day 90; ghrelin may be involved in gastrointestinal tract development.

A GaN film with a thickness of 250@mm was grown on a GaN/sapphire template in a vertical hydride vapor phase epitaxy (HVPE) reactor. The full-width at half-maximum (FWHM) values of the film were 141 and 498arcsec for the (002) and (102) reflections, respectively. A sharp band-edge emission with a FWHM of 20meV at 50K was observed, which corresponded to good crystalline quality of the film. Some almost circular-shaped hillocks located in the spiral growth center were found on the film surface with dimensions of 100@mm, whose origin was related to screw dislocations and micropipes. Meanwhile, large hexagonal pits also appeared on the film surface, which had six triangular {101@?1} facets. The strong emission in the pits was dominated by an impurity-related emission at 377nm, which could have been a high-concentration oxygen impurity.

Single-crystalline 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP) microrods were prepared by a facile solution process. The PPCP microrods with smooth surfaces could absorb excitation light and propagate the photoluminescence (PL) emission. They showed excellent properties in the low optical loss of a single rod and feasible transfer between neighboring rods. Moreover, PPCP displayed typical aggregation-induced emission enhancement (AIEE) characteristics in the solution state.

A 275 mu m thick GaN layer was directly grown on the SiO2-prepatterned sapphire in a home-built vertical hydride vapour phase epitaxy (HVPE) reactor. The variation of optical and structure characteristics were microscopically identified using spatially resolved cathodeluminescence and micro-Raman spectroscopy in a cross section of the thick film. The D X-0(A) line with the FWHM of 5.1 meV and etch- pit density of 9 x 10(6) cm(-2) illustrated high crystalline quality of the thick GaN epitaxial layer. Optically active regions appeared above the SiO2 masks and disappeared abruptly due to the tapered inversion domains at 210 - 230 mu m thickness. The crystalline quality was improved by increasing the thickness of the GaN/sapphire interface, but the region with a distance of 2 mu m from the top surface revealed relatively low quality due to degenerate surface reconstruction by residual gas reaction. The x-ray rocking curve for the symmetric (0 0 2) and asymmetric (1 0 2) reflections also showed good quality and a small wing tilt of the epitaxial lateral overgrowth (ELO) GaN.

The influence of interface growth interruption on electron spin relaxation time tau s in GaAs/AlGaAs (1 1 0) quantum wells (QWs) grown by solid source molecular-beam epitaxy (SSMBE) has been investigated by grazing incidence X-ray reflectivity and time-resolved Kerr rotation spectroscopy (TRKR). Various inverted interface interruption times were used in growing QWs. Interface roughness of these QW samples was studied by grazing incidence X-ray reflectivity. The simulated results of reflectivity, curves by standard software indicated that interface roughness decreased as the interface growth interruption time increased. TRKR measurements at room temperature showed that the appropriate growth interruption could increase spin relaxation time in GaAs/AlGaAs QWs drastically. This dramatic increase was explained by the suppression of the D'yakonov-Perel' interaction. (c) 2006 Elsevier B.V. All rights reserved.

Large-size single crystalline nanosheets of 9,10-bis(phenylethynyl)-anthracene were prepared by a facile solution process and were fully characterized. The prototype photodetector was then fabricated on the basis of a single nanosheet and exhibited superior performance with the largest photoresponse ratio up to ca. 10(5). Moreover, the nanosheets show obvious light emission anisotropy.

Silver (Ag) nanodecahedrons have been synthesized for the first time by liquid-phase reduction of AgNO3 with assistance of polyvinylpyrrolidone (PVP) in a large scale. The edge size of Ag decahedrons is estimated to be ca. 80 nm. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) have been employed to elucidate the five-twinned structure of Ag decahedrons. The results show that the Ag decahedrons capped by PVP molecules hold five-twinning structure with distinct twinning boundaries. The growth process of Ag decahedrons has been investigated and their growth mechanism has been proposed. Combined with our previous reports on Ag nanowires with pentagonal cross section, it is revealed that the Ag nanodecahedrons might be assembled from five tetrahedrons step by step. Further studies on the role of PVP conformation in different solution reduction systems are required. (c) 2006 Elsevier B.V. All rights reserved.

High quality ZnO films have been successfully grown on a Si (100) substrate by metal organic chemical vapour deposition with a γ-Al2O3 buffer. The crystal structure, surface morphology and optical properties of the ZnO films were characterized by x-ray diffraction, Raman spectroscopy, atomic force microscopy and photoluminescence (PL) spectroscopy. The properties of the films with the Al2O3 buffer were improved in comparison with those of as-grown ZnO films. It is shown that the ZnO films with the γ-Al2O3 buffer grown on Si (100) substrates have a highly-preferential c-axis (0002) orientation, a narrow (0002) peak, smooth surface morphology and better PL spectral properties. This demonstrates that the use of γ-Al2O3/Si as a ZnO substrate is beneficial for reducing the residual stress for further growth of ZnO films, compared with the growth on bulk Si substrates.

Hetero-junction beaded nanowires were synthesized via a simple thermal vapor deposition method. These nanowires were characterized with XRD, Raman, SEM, TEM, HRTEM, SAED and PL spectroscopy. Many single-crystal In2O3 beads epitaxially grown along the axis of the single-crystal core SnO2 nanowires form the beaded nanowires. The In2O3 beads have definite orientations along the [200] direction of the core SnO2 nanowires and show regular rhombohedral morphology. A possible growth mechanism for the beaded nanowires is proposed. (c) 2005 Published by Elsevier B.V.