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Background MicroRNAs (miRs) are known to participate in sepsis; hence, we aim to discuss the protective effect of miR-499-5p targeting sex-determining region Y-related high-mobility-group box 6 (Sox6) on sepsis-induced lung injury in mice. Methods The sepsis-induced lung injury model was established by cecal ligation and puncture. The wet/dry weight (W/D) ratio, miR-499-5p, Sox6, Caspase-3 and Caspase-9 expression in lung tissues of mice were tested. Lung injury score, collagen fibers and the degree of pulmonary fibrosis in lung tissues were determined. Further, the cell apoptosis in lung tissues was measured. The inflammatory factors contents and oxidative stress indices in bronchoalveolar lavage fluid (BALF) and lung tissues were detected via loss- and gain-of-function assays. The targeting relation between miR-499-5p and Sox6 was verified. Results W/D ratio and Sox6 were increased while miR-499-5p was decreased in lung tissues of sepsis-induced lung injury mice. Restored miR-499-5p or depleted Sox6 alleviated lung tissues pathology, reduced lung injury score, collagen fibers, the degree of pulmonary fibrosis, TUNEL positive cells, Caspase-3 and Caspase-9 protein expression and inflammatory factors contents in BALF and lung tissues as well as oxidative stress response in lung tissues of sepsis-induced lung injury mice. miR-499-5p targeted Sox6. Conclusion High expression of miR-499-5p can attenuate cell apoptosis in lung tissues and inhibit inflammation of sepsis-induced lung injury mice via depleting Sox6, and it is a potential candidate marker and therapeutic target for sepsis-induced lung injury.

Because the application of zonation test and multilayer test is rare, the well tests of most multilayer edge-water gas reservoirs are often interpreted with singer layer model, which lead to erroneous analyses. In order to recognize the edge-water and obtain the parameters in multilayer gas reservoirs accurately, a well test model of a vertical well in multilayer edge-water gas reservoirs considering the distinct respective properties and distinct respective distances to edge-water in each layer is established and solved. Type curves of pressure transients are plotted. The effects of distinct properties between layers on the well test type curves with different distance to edge-water are analyzed. The results showed that the effect of edge-water is reflected early on type curves due to the distinct diffusivity between layers. This results in relatively small value of the minimum distance to edge-water which is interpreted with a singer layer model. The greater the different diffusivity between layers the earlier the reflective of edge-water on type curves. The greater the different diffusivity between layers the smaller interpretative value of the minimum distance to edge-water too. Therefore, a well test interpretation method of a vertical well in multilayer edge-water gas reservoirs is proposed which combines the single layer edge-water well test interpretation, multilayer edge-water well test model and the ratio of formation capacity and porosity between layers from well log interpretation. The correct value of minimum distance to edge-water and the approximate permeability of each layer can be obtained by use of the proposed well test interpretation method. Field case buildup analyses of a gas well in multilayer edge-water gas reservoirs show the applicability of the new well test interpretation method.

Oxidative desulfurization is considered to be one of the promising new methods for super-deep desulfurization of fuel oil. Herein, zinc phthalocyanine/g-C3N4 (g-C3N4/ZnTcPc) composites were synthesized by a facile in situ hydrothermal technique, utilizing g-C3N4, Zn(CH3COO)2 and 1,2,4-benzenetricarboxylic anhydride as the precursors. The crystal structure, morphology and chemical environment of the catalysts were respectively confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity of the resulting g-C3N4/ZnTcPc composites was evaluated by desulfurization of thiophene in fuel under visible light with molecular O2 as the oxidant. Compared with pure g-C3N4 and ZnTcPc, g-C3N4/ZnTcPc presented a significantly enhanced photocatalytic activity for the degradation of thiophene in fuel under visible irradiation. Sulfur content of model gasoline (800 ppm) after desulfurization for 90 min was decreased to 125 ppm. The possible preparation pathway of g-C3N4/ZnTcPc has been proposed according to the results of XRD and TEM. The formation mechanism of g-C3N4/ZnTcPc–O2 complex is proposed to be desulfurization by molecular oxygen.

Magnetocrystalline anisotropy energy is the core concern in the field of magnetic storage theory. This study explored the theoretical mechanism of magnetocrystalline anisotropy energy of monolayer iron with the change of strain by using an Orbital Selective External Potential (OSEP) method. It is found that magnetocrystalline anisotropy energy of monolayer iron changes linearly with the strain through first principles calculation. We predict the contribution of 3 d z 2 orbital using matrix-analysis. Particularly, we utilize the Orbital Selective External Potential to shift the energy levels of 3d orbitals, observing the occupation number influence on magnetocrystalline anisotropy energy. As a result, we confirmed the main contribution of 3 d z 2 orbital. It is the first application of OSEP method in solving the strain effect of magnetocrystalline anisotropy in 3d ferromagnet systems. This research will help understand the theoretical mechanism of magnetic memory devices based on spintronics.

In this work, Co 2D antidot arrays with well-ordered hexagonal holes ranging in size from 1.3 to 6.2 μm were fabricated by colloidal crystal template method. The geometry configuration and magnetic properties of the samples were investigated. An enormous increase in coercivity and squareness, as compared with the corresponding continuous film, was observed. Magnetic properties of Co 2D antidot arrays showed a close dependence on pore diameter. According to geometric calculation, the effect of the pore diameter on magnetic properties was also discussed. The Co 2D antidot arrays obtained by this method are promising candidates for high-density information storage.

Terahertz-streaking photoionization can be exploited to resolve ultrafast quantum beating and reconstruct the ultrafast evolution of density matrix. Here, we propose an experimental strategy to implement the method merely with the tabletop femtosecond system and magneto-optical trap reaction microscopy. The probe pulse consists of an ultraviolet pulse with pulse duration of about 30 fs and a strong terahertz pulse with strength of about 2.6 fs in rubidium-atom superposition. The population and coherence terms of the density matrix can be projected into different positions of the photoelectron momentum distribution. The reconstruction algorithm was designed to acquire the ultrafast evolution of density matrix from the time-dependent photoelectron spectrum. The experimental conception can demonstrate the newly proposed transient spectral method only with the commercial femtosecond laser system and magneto-optical trap reaction microscopy, thus preventing the complex laser system, such as extreme ultraviolet free electron lasers and attosecond higher harmonics, allowing a new metrology to explore the coherence dynamics of quantum systems.

Physiologic anchorage Speewire system (PASS) technique is based on physiologic anchorage control theory. It is based on craniofacial growth, dentoalveolar compensation, physiologic curve of Spee, principle of differential moments, and the advantage of light force low friction. PASS appliance consists of XBT buccal tube and MLF bracket.

The origin of THz generation in dual-color laser fields is investigated by joint measurement of THz and third-harmonic generation, showing the single-atom-ionization determined THz wave is modulated by photocurrent behavior.

Dentitions drift forward by physiological force from the tongue, bite force, eruption force, etc. until the anterior force from the lips can stop it to reach a balance. Our recent study and others all show after extraction of premolars, anterior teeth drift backward, and posterior teeth drift forward (another source of physiologic anchorage loss). Alexander therefore advocated to delay the bonding of the lower arch to take advantage of natural drifting to relieve anterior crowding, implying teeth will not drift after putting on a fixed appliance. Friction is believed to be a resistance for teeth sliding along the archwire, so theoretically lowering the friction will reduce resistance for canine sliding backward. With XBT buccal tube, molars are prevented from forward drifting from very first thin nickel-titanium (NiTi) archwire. If we can induce canine sliding back along the archwire with low friction, we can relieve anterior crowding without stressing anchor molar with laceback or tieback to save anchorage in initial alignment stage.

Ba0.2Sr0.8Co0.9Nb0.1O3-δ(BSCN0.2)-xGd0.1Ce0.9O1.95(GDC) (x = 10, 20, 30 and 40 wt.%) composite cathodes were investigated for the potential application in the IT-SOFCs. The results of chemical compatibility measurement show that a small number of Gd and/or Ce ions may melt into the lattice of BSCN0.2 to form BSCN0.2-GDC solid solution. Thermal expansion coefficients effectively reduced by the incorporation of GDC. The electrochemical performance of BSCN0.2-xGDC composite cathodes increased with increasing x from 10 to 30 wt.%. When x = 30 wt.%, the area specific resistances were only 0.040 and 0.017 Ω cm2at 750 and 800oC, respectively. This improved electrochemical performance is attributed to the good thermal expansion match between BSCN0.2-xGDC composite cathode and GDC electrolyte, and the increased oxygen vacancy concentration. With further increasing x, the electrochemical performance of the composite cathode decreased. This result may be due to the ambipolar resistance model of porous composite cathode and the poor electrical conductivity of BSCN-40GDC. The maximum power densities of a BSCN0.2-30GDC/La0.9Sr0.1Ga0.8Mg0.2O3-δ/NiO-Sm0.2Ce0.8O1.9single-cell achieve 537 and 722 mW cm-2at 750oC and 800oC, respectively. These results indicate that the BSCN0.2-30GDC composite cathode is a promising candidate for IT-SOFC.

An obvious increase in the gate leakage current has been commonly observed in GaN HEMTs, after Plasma-enhanced chemical vapor deposition (PECVD) SiN passivation has been observed to obviously increase. This paper presents an Al/SiN stack layer passivation structure. The high gate leakage current in GaN HEMTs caused by the PECVD SiN passivation is distinctly reduced by 2 to 3 orders of magnitude by introducing a thin Al layer. It is mainly attributed to the Al layer blocking and minimizing the damage for the (Al)GaN surface in the build-up of the luminance process of PECVD SiN and then reducing the surface trap density. TEM mapping and SRIM software simulation reveal that neither damage nor inter-diffusion is demonstrated at the Al/AlGaN interface, where a continuous crystalline region is observed. The moderate current collapse suppression and 32.8% improvement in VBR are achieved in GaN HEMTs with Al/SiN passivation.

During the application of solid expandable tubular (SET) technology, the friction between expansion cone and tubular results in high expansion pressure, high operational risk, and severe abrasion of expansion cone over long distance operation. So far, traditional methods have not been able to effectively achieve the purpose of reducing the friction and improving the wear resistance of expansion cone. The bionic non-smooth surface has been studied and confirmed to have characters of reducing friction and wear, and these characteristics have been successfully applied in many fields. In this paper, the bionic non-smooth theory was applied on the surface of expansion cone, and bionic cone was fabricated by laser texturing and carbon based coating. The ground tests proved that the bionic surface treatment on the expansion cone could reduce the expansion pressure by 15% at least and improve the wear resistance.

Welding joint of GH4169 alloy with a good formation was obtained. No macroscopic defects occurred in the joint. The weld had mainly a dendritic structure; the base metal was a solid solution of Ni, Cr, and Fe, and the strengthening-phase particles such as Ni 3 Nb were dispersively distributed along the grain boundary. The average tensile strength of the joint reached 743.7 MPa, and the Vickers hardness of the weld exceeded HV 300. Because of the segregation of the low-melting compound Ni 3 Nb at the grain boundary of the fusion zone, liquid cracks tended to occur as a result of welding stress. The formation of liquid cracks was inhibited by adding an alloying element, Mn, to the welding bath, because Mn diffused to the fusion zone and the high-melting phase Mn 2 Nb formed, and thus the overall properties of the joint were improved.

The atomic-scale friction in fluorographene and graphane is investigated employing the density functional theory calculation including the dispersion correction (DFT-D). Fluorographene and graphane exhibit low friction because of the low interlayer interaction induced by the repulsive electrostatic forces between F or H atoms at the interfaces. Moreover, owing to the less electronegativity of H atoms than F atoms, the variation of interlayer spacing and system energy corrugation, which is predominantly determined by the variation of dispersion energy during both loading and sliding processes, as elucidated in this paper, is found to be much larger in graphane, which well explains the larger friction in graphane than in fluorographene. The more charged F atom in fluorographene diminishes the variation of the interlayer spacing, which finally decreases the variation of the dispersion energy in the fluorographene. The study theoretically reveals the general mechanism of atomic-scale friction in various graph...

Mn doped graphene-based dilute magnetic semiconductors (DMS) are investigated using the first-principle calculation based on density functional theory. In this paper, the Mn-C bond length, formation energy and magnetic moment are calculated in different doping systems and their density of states is made a detailed analysis. It is found that Mn-doped graphene has strong ferromagnetic properties and the magnetic moments of graphene supercells are different with the impurity concentrations. These supercells of a Mn atom substituting a C atom are increasingly stable with extending cells and the 11×11 supercell possesses the biggest magnetic moment of 3.8μB in these systems. The analysis of the density of states indicates the magnetic properties of Mn-doped graphene derive from the p-d exchange mechanism.

Large area epitaxial graphene (EG) layers are synthesized on 6H-SiC (0001) by annealing at 1500 °C for 5 min in a closed graphite chamber at low vacuum of 10-3 mbar and its 2D band in Raman spectra can be satisfactorily fitted by a single Lorentzian. From Raman spectroscopy, measurements indicate that too high growth temperature is to the disadvantage of the formation of graphene. The results of atomic force microscope (AFM) and field-emission scanning electronic microscope (FE-SEM) reveal the surface morphology of graphene is related with its growth temperature.

Magnetic properties of 6H-SiC doped with transition metal (TM) atoms are calculated using the density functional theory method (DFT). It is shown that TM doped in a 6H-SiC host may have both magnetic and nonmagnetic states. From the figures of their density of states (DOS) and partial density of states (PDOS) and to compare the energy differences between ferromagnetic and nonmagnetic states, we demonstrate that Cr and Mn-doped 6H-SiC emerge a half-metallic ferromagnetic state, Co and Ni-doped 6H-SiC create very little magnetic features, while Fe-doped 6H-SiC is in the nonmagnetic state. We also calculate the energy differences between ferromagnetic and antiferromagnetic of Cr, Mn and Fe-doped 6H-SiC in the doping concentration (8.34%). It is found that the energy of the antiferromagnetic state is lower than that of the ferromagnetic state.

The technique of ion mobility spectrometry (IMS) offers a practical and fast detecting method in ambient conditions to estimate whether there may presence contrabands or even chemical warfare agents (CWAs). In this work we have investigated a self-made radioactive 63Ni (β emission) ionization source for ion mobility spectrometry employed with an atmospheric pressure to detect real CWAs, such as GB, GD, HD, VX from aerosol samples. Furthermore, we have experimentally studied the influence of drift tube temperature not only in ion cluster formation in the positive mode, but also the detection limitation of CWAs.

The niobium film is prepared by magnetron sputtering on the surface of the AZ91D magnesium alloy. The morphology, phase structure, roughness, nanohardness and elastic modulus of the niobium films were studied by filed emission scanning electron microscope, X-ray diffraction, atomic force microscope and nanoindentation respectively. The influences of film deposition parameters, such as substrate temperature, negative bias and power on the properties of films were investigated. The corrosion resistance of niobium films on magnesium alloy was investigated by electrochemical system. Results show that the microstructure, phase structure, roughness, nanohardness and elastic modulus of the niobium films are determined by power, negative bias and substrate temperature. And the corrosion resistance of magnesium alloy improved obviously when coated with the niobium films.

According to the nutation movement of a rotating coin on a table, a novel nutation drive with rolling teeth is presented on the basis of oscillating teeth gear transmission. Firstly, the structure of mechanism is provided and transmission theory is declared. The formulae for calculating the transmission ratio of the mechanism is developed. Secondly, the modeling of this nutation drive is built. Finally, the results of theoretical calculations are verified by dynamic motion simulation of the prototype mechanism. In addition, Numerical control(NC) simulation of machining the stator and the rotor gears is developed.

Zn 0.95 Co 0.05 O and Zn 0.91 Co 0.05 Cu 0.04 O thin films were fabricated on Si (111) substrate by the reactive magnetron sputtering method at different O-Ar ratios. Detailed characterizations by X-ray diffractometry (XRD), X-ray photo-electronic spectrum (XPS), and electron paramagnetic resonance (EPR) indicate that the doped Cu ions substitute the Zn 2+ ions in the ZnO lattice. The doped Cu ions are in Cu + and Cu 2+ mixture valence states. The ferromagnetism of the Zn 0.91 Co 0.05 Cu 0.04 O film increases gradually the increasing Cu + ions concentration. The results indicate that the increase of ferromagnetism is not owing to the magnetic contribution of Cu + ions themselves, but owing to the enhancement of magnetic interaction between Co ions, which suggests that p-type doping of Cu + ions plays an important role in mediating the ferromagnetic coupling between Co ions.

This paper concentrates on the impact of SiN passivation layer deposited by plasma-enhanced chemical vapor deposition (PECVD) on the Schottky characteristics in GaN high electron mobility transistors (HEMTs). Three types of SiN layers with different deposition conditions were deposited on GaN HEMTs. Atomic force microscope (AFM), capacitance–voltage (C–V), and Fourier transform infrared (FTIR) measurement were used to analyze the surface morphology, the electrical characterization, and the chemical bonding of SiN thin films, respectively. The better surface morphology was achieved from the device with lower gate leakage current. The fixed positive charge Q f was extracted from C–V curves of Al/SiN/Si structures and quite different density of trap states (in the order of magnitude of 1011–1012 cm−2) was observed. It was found that the least trap states were in accordance with the lowest gate leakage current. Furthermore, the chemical bonds and the %H in Si–H and N–H were figured from FTIR measurement, demonstrating an increase in the density of Q f with the increasing %H in N–H. It reveals that the effect of SiN passivation can be improved in GaN-based HEMTs by modulating %H in Si–H and N–H, thus achieving a better Schottky characteristics.

Zn0.95Co0.05O nanocrystals were synthesized by the sol−gel method. A STEM image clearly shows that the Co in ZnO nanocrystals is of surface-preferential. To further study the distribution state of Co element and its effects on the structure and magnetic property, were postannealed the Zn0.95Co0.05O nanocrystals in O2, Ar, and H2 atmospheres. It is found that the ferromagnetisms of the H2- and Ar-annealed Zn0.95Co0.05O nanocrystals increase significantly, but that of the O2-annealed sample decreases. The ferromagnetism variations of the Ar- and O2-annealed sample are stemmed from the increase of oxygen vacancies (Vo) and the formation of second-phase Co3O4, respectively, whereas the great enhancement of ferromagnetism in the H2-annealed sample is attributed to the appearance of interstitial H (Hi) related defects. Our results indicate that inhomogeneous Co distribution is helpful for manipulating the states of the Co ions and the ferromagnetic coupling in Zn1−xCoxO by post-treatment.

Amorphous ribbons of Co 68.5 Fe 4 Si 10 B 17.5 were prepared by a single roller melt-spinning technique in the air atmosphere. The crystallization products were analyzed by X-ray diffraction. The crystallization kinetics of the alloys were investigated by means of differential scanning calorimetry (DSC) in the mode isothermal annealing. It is found when the isothermal kinetics was modeled by the Johnson–Mehl–Avrami equation, the Avrami exponents are calculated to be in the range of 2.11–2.58 for different isothermal temperatures. This implies that the crystallization of Co 68.5 Fe 4 Si 10 B17.5 amorphous alloy is governed by either diffusion or interface controlled three-dimensional growth, depending on the annealing temperature. On the basis of the Arrhenius relation, the activation energy E c in the isothermal process is calculated to be 113.67 kJ/mol. Finally, details of the nucleation and growth behaviors during the isothermal crystallization are discussed.

Mo, Al2O3 single layer, Mo–Al2O3 granular cermet layer, Mo/Al2O3 tandem and an optimized Mo–Al2O3 multilayer coating with a double cermet layer configuration were deposited on stainless steel substrates by magnetron sputtering technique. The samples were annealed in vacuum at different temperatures ranging from 350 °C to 1000 °C for 2–5 h to evaluate their thermal stability. The spectral absorbance and thermal emissivity for the multi-layer selective coatings in the region of 1.3–25 μm were 0.91–0.93 and 0.19–0.27, respectively, depending on heat treatment temperature. Increasing annealing temperature has more obvious influence on the rise of emissivity than the drop of spectral absorbance. The microstructure, surface morphology, composition distribution and diffusion for various films before and after high temperature aging were investigated employing scanning electronic microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Fe2O3, as a diffusion barrier between Mo layer and SS substrate, effectively holds back the presence of Mo2C and Fe2MoC complex phases. Al2O3 is a stable phase even at 1000 °C for 3 h. However, defects such as widened boundaries, cracks and holes, which could appear in Al2O3 layer when heated at higher temperature than 650 °C, will provide the paths of Mo diffusion. Two diffusion modes of Mo, including inner self-congregation of Mo inside the cermet layer and Mo infiltration through the Al2O3 layer in Mo/Al2O3 tandem at 800 °C for 5 h, were observed after annealing.

Transparent conductive oxide (TCO) thin film is a kind of functional material which has potential applications in solar cells and atomic oxygen (AO) resisting systems in spacecrafts. Of TCO, ZnO:Al (ZAO) and In2O3:Sn (ITO) thin films have been widely used and investigated. In this study, ZAO and ITO thin films were irradiated by AO with different amounts of fluence. The as-deposited samples and irradiated ones were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Hall-effect measurement to investigate the dependence of the structure, morphology and electrical properties of ZAO or ITO on the amount of fluence of AO irradiation. It is noticed that AO has erosion effects on the surface of ZAO without evident influences upon its structure and conductive properties. Moreover, as the amount of AO fluence rises, the carrier concentration of ITO decreases causing the resistivity to increase by at most 21.7%.

A new cermet film Nb-NbN, deposited on the stainless steel substrate by direct reactive magnetron sputtering, was reported as solar selective absorptive coating. Some fundamental studies on microstructure and optical properties of the Nb-NbN cermet films were carried out by XRD, EDX, SEM and spectrophotometer. A solar absorptivity of 0.94 and a normal emissivity of 0.16 at room temperature were achieved for the coating. Thermal stability was investigated at 350°C and 500°C and it was observed that the absorptivity was changed in a range from 0.92 to 0.94 and the surface emissivity varied firstly from 0.16 to 0.14 and then increasing to 0.19 when the temperature was increased from room temperature to 350°C and up to 500°C.

Ga 2 O 3 : Eu 3+ Powder was synthesized by sol-gel method with inorganic salt raw materials, and the crystal structure and luminescent properties were investigated. The structures studied by X-ray diffractionmeter showed that single monoclinism could be obtained using this simple processing. Along with the rise of the calcining temperature, the crystallinity of Ga 2 O 3 :Eu 3+ powder increased and the particle size grew larger. The excitation spectra of the powder showed a wide CTS band and typical excitation from Eu 3+ ion, while the emission spectra had a strongest red emission peak at 613 nm. The excitation and emission intensities changed along with the calcining temperature from 650 to 1050 °C and had an optimal calcining temperature. The excitation and emission intensities also changed along with the doping concentration of Eu 3+ ion from 0.25% to 4% (atom fraction) and achieve a maximum at a certain concentration which differed for direct Eu 3+ excitation or CTS excitation. The electroluminescent spectra indicated the typical red emission from Eu 3+ ion.

Some fundamental studies on the preparation, structure and optical properties of NbN films were carried out. NbN thin films were deposited by DC reactive magnetron sputtering at different N2 partial pressures and different substrate temperatures ranging from −50 °C to 600 °C. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) were employed to characterize their phase components, microstructures, grain sizes and surface morphology. Optical properties inclusive of refractive indexes, extinction coefficients and transmittance of the NbN films under different sputtering conditions were measured. With the increase in the N2 partial pressure, δ-NbN phase structure gets forming and the grain size and lattice constant of the cubic NbN increasing. The deposited NbN film has relatively high values of refractive index and extinction coefficient in the wavelength ranging from 240 nm to 830 nm. Substrate temperature exerts notable influences on the microstructure and optical transmittance of the NbN films. The grain sizes of the δ-NbN film remarkably increase with the rise of the substrate temperature, while the transmittance of the films with the same thickness decreases. Ultra-fine granular film with particle size of several nanometers forms when the substrate is cooled to −50 °C, and a remarkable augmentation of transmittance could be noticed under so low a temperature.

TiO2/PSS nano-structured multilayer films are fabricated by a layer-by-layer self-assembly method, and the deposition process and interface structure of films are studied in detail by slow positron spectroscopy. The results indicate that injection energy of positron at the interface between the substrate and the Elm shows a linear dependence on the number of bilayer, which suggests that the repeatability of the depositing process is good, and the thickness of films shows a linear, increase with the number of bilayers adding. The calculated result of the film thickness shows that there is an overlay between the adjacent TiO2 nanoparticle layers.

Diamond like carbon (DLC) films were prepared on Si wafer, using laser induced arc deposition (Laser arc) technique. Results of Raman Spectra analysis showed that the as-deposit films were amorphous, having obvious sp3 structure. Meanwhile, surface topography and micro-tribological properties were investigated by using Atomic Force Microscope and Nano-Scratch Tester. Influences of arc voltage, substrate bias voltage, target materials and substrate pre-treatment methods upon the film structures and film properties were studied.

Preferred growth of nanocrystalline silicon (nc-Si) was first found in boron-doped hydrogenated nanocrystalline (nc-Si:H) films prepared using plasma-enhanced chemical vapor deposition system. The films were characterized by high-resolution transmission electron microscope, X-ray diffraction (XRD) spectrum and Raman Scattering spectrum. The results showed that the diffraction peaks in XRD spectrum were at 2theta approximate to 47degrees and the exponent of crystalline plane of nc-Si in the film was (220). A considerable reason was electric field derived from dc bias made the bonds of Si-Si array according to a certain orient. The size and crystalline volume fraction of nc-Si in boron-doped films were intensively depended on the deposited parameters: diborane (B2H6) doping ratio in silane (SiH4), silane dilution ratio in hydrogen (H-2), rf power density, substrate's temperature and reactive pressure, respectively. But preferred growth of nc-Si in the boron-doped nc-Si:H films cannot be obtained by changing these parameters. (C) 2004 Elsevier Ltd. All rights reserved.

Impact assessment for laser hardened hypoeutectoid 2Cr13 martensite stainless steel was carried out on a specifically developed ball-on-flat impact tester. Results showed better impact behavior of 2Cr13 surfaces treated by a continuous wave CO2 laser than those under conventional heat treatment. Micro-hardness measurement demonstrated that the surface hardness of the laser treated specimens varied with the operation parameters of laser hardening. Scanning electron microscope (SEM) analysis and surface profile measurement suggested that the size of the impact wear scars of 2Cr13 specimens decreases with the increase of the surface hardness. EDX analysis showed that the oxidation resistance of the laser-hardened surfaces was relatively superior to their conventionally heat-treated counterparts. Compared with conventionally-treated 2Cr13 steel, the superior impact wear resistance of laser surface-processed steel was attributed both to grain refinement and to the higher martensite content near the surface that resulted from rapid cooling.

We employ an optical second harmonic generation(SHG) technique to investigate the surface behaviours at the liquid(solid)/vapour interface of the Ga-Bi binary metallic system. In a heating and cooling cycle between 280°C and room temperature, there is no change of the SH-intensity in the heating process, whereas there exists an abrupt and abnormal change of the SH-intensity in the cooling process. It is interesting to find that a macroscopic Bi-rich solid layer is floating on the surface of the Ga-rich liquid phase just below the monotectic temperature (222°C±2°C) in the cooling process, in spite of the Bi-rich phase being heavier than the Ga-rich phase. On the other hand, different undercooling behaviours are observed at the surface and in the bulk. The behaviours of surface solidification and surface melting are different from those in the bulk.

Ga1−xInxSb (x=0.19, 0.38, 0.63) nanoparticles embedded in a SiO2 matrix were grown on the glass substrates by radio-frequency magnetron co-sputtering. X-ray diffraction patterns strongly support the existence of nanocrystalline Ga1−xInxSb in the SiO2 matrix. The changes in binding energies with Ga1−xInxSb nanocrystals deposition have been directly observed by X-ray photoemission spectroscopy, and these show the existence of Ga1−xInxSb nanocrystals in the SiO2 matrix. Room-temperature Raman spectra show that the Raman peaks of the Ga1−xInxSb–SiO2 composite film have a larger red-shift of about 95.3 cm−1 (longitudinal-optical mode) and 120.1 cm−1 (transverse-optical mode) than that of bulk GaSb, suggesting the existence of phonon confinement and tensile stress effects. Additionally, the room-temperature optical transmission data exhibit a large blue-shift with respect to that of the bulk semiconductor due to the strong quantum confinement effect.

An all-thin-film (ATF) electrochromic device for modulating the optical transmittance is manufactured using magnetron sputtering. The devices consists of MoO3 as the main electrochromic layer, LiBO2+Li2SO4(LiBSO) as the ion conductor layer, and NiOx as the complementary electrochromic layer. Glass covered with indium tin oxide (ITO) is used as the substrate and the ITO film is used as the bottom electrode. The ITO film deposited o the top of the devices is used as the other electrode. The structure and morphology of the films are characterize by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The devices exhibit good optical properties with low transmittance values in the coloured state, and the optical modulation is measured by spectrophotometer in the wavelength range from 400 to 800 nm. The average visible light transmittance reaches 50.2% and 3.7% i bleached and coloured state, respectively. The results indicate that such a monolithic system has great potential to be applied in smart windows.

A new composite system is fabricated by depositing the TiO2 film on a silicon nanoporous pillar array (Si-NPA) and annealing at 500°C using the spin coating method. Such a composite system exhibits a uniform morphology with the micron-dimension pillar array. Photocatalytic properties are investigated based on the degradation of methyl orange dye solution, and the results show that the photocatalytic efficiency of such a nano-composite system is 1.7 times that of the TiO2/glass system. The enhancement of photocatalytic efficiency is attributed to the large surface area of the TiO2/Si-NPA system.

Commercial pure iron was treated by Al + N + and Ti + N + ion beam assisted deposition (IBAD). The authors investigated the friction and wear properties of samples before and after the treatment. The microstructures, composition and morphology of the wear surfaces were analyzed and the properties of the modified layers were studied. The mechanisms of the improvement of the friction and wear properties were also discussed. The experimental results indicate that the IBAD with Al + N + or Ti + N + can effectively decrease the friction coefficients and strikingly improve the wear resistance. The compounds of Fe 4 N and Fe 3 Al formed in the surface layers of pure iron when treated by Al + N + , while Fe 2 N and Fe 2 Ti formed when treated by Ti + N + . These compounds much strengthen the surfaces. The IBAD treatment also promotes the formation and reform of the oxide films during the wearing process. These may transform the wear mechanism of pure iron from adhesive wear to adhesive/oxidative wear.

Intrinsic nanocrystalline silicon films (nc-Si:H) were prepared by plasma enhanced chemical vapor deposition (PECVD) method. Films' microstructures and characteristics were studied with Raman spectroscopy and Atom Force Microscope (AFM). The electronic conductivity of nc-Si:H films was found to be 4.9 x 10(0)Omega(-1) cm(-1), which was one order of magnitude higher than the reported 10(-3)-10(-1)Omega(-1)cm(-1). And PIN solar cells with nc-Si:H film as intrinsic thin-layer (ITO/n(+)-nc-Si:H/i-nc-Si:H/p-c-Si/Ag) were researched. The cell's performances were measured, the open-circuit voltage V-oc was 534.7 mV, short-circuit current I-sc was 49.24 mA (3 cm(2)) and fill factor FF was 0.4228. (c) 2006 Elsevier Ltd. All rights reserved.

Threshold displacement energies for atomic displacements along some interesting directions, and formation energies of vacancy, anti-site and several symmetric interstitial atom configurations are calculated for a TiAl alloy by a molecular dynamic method using the Finnis-Sinclair many-body potentials in this paper. The results show that, the four possible octahedral configurations are unstable and the Al(Al) [110] crowdion is energetically favored in the five stable interstitial configurations. In most directions the displacement energies for Al PKA are larger than those for Ti PKA, the strength of the interaction potentials is only determinative along [110] and [100], the values of E d of the Ti atom are larger than those of the Al atom. The results also show that the displacement energy along [001] is larger than that along the [100] direction both for the Ti atom and the Al atom.

The molecular dynamics method with a many-body potential is used to calculate the formation energies and combination energies of a monovacancy, bivacancy, trivacancy and tetravacancy with different configurations in under periodic boundary conditions. The favourable configurations in energy for the small vacancy clusters are obtained. In addition, we evaluate the activation energies for monovacancy migrations and analyse the effect of a vacancy cluster on its neighbouring vacancy migrations.

This paper describes and analyses the impact of the Ti layer, which is embedded between the insulator and top electrode, on the programming characteristic of the Al—HfO2—Al antifuse. The programming voltage of the antifuse with 120 A HfO2 is properly reduced from 5.5 to 4.6 V with an embedded Ti layer. Low on-state resistance (~19 Ω) and low programming voltage (4.6 V) is demonstrated in the embedded Ti antifuse with 120 A HfO2 while keeping sufficient off-state reliability. The antifuse embedded with a Ti layer between the insulator and top electrode has been developed and has potential in field programmable devices.

We present a passively phase-stabilized two-dimensional electronic spectroscopy (2DES) with a compact size, and the ease of implementation and maintenance. Our design relies on a mask beam-splitter with four holes to form non-collinear box geometry, and a homebuilt stacked retroreflector, which introduces the phase-locked pulse sequence, remedying the instability of commonly used translation stages. The minimized size of the setup suppresses the influences of optical path-length fluctuations during measurements, improving the phase stability and precise timing of pulse sequences. In our 2DES, only few conventional optical components are used, which make this sophisticated instrumentation convenient to establish and particularly easy to conduct alignment. In data analysis, the self-referencing spectral interferometry (SRSI) method is first introduced to extract the complex-valued signal from spectral interferometry in 2DES. The alternative algorithm achieves the improvement of the signal-to-noise ratio (SNR) and considerable reduction of data acquisition time. The new setup is suitable over a tunable range of spectroscopic wavelength, from ultraviolet (UV) to the near-infrared (NIR) regime, and for ultra-broadband bandwidth, few-cycle laser pulses.

International audience; Midinfrared strong-field laser ionization offers the promise of measuring holograms of atoms and molecules, which contain both spatial and temporal information of the ion and the photoelectron with subfemtosecond temporal and angstrom spatial resolution. We report on the scaling of photoelectron holographic interference patterns with the laser pulse duration, wavelength, and intensity. High-resolution holograms for the ionization of metastable xenon atoms by 7-16 m light from the FELICE free electron laser are presented and compared to semiclassical calculations that provide analytical insight.

Crystalline SiC samples were prepared in solidification of silicon melt saturated by carbon solved from the inner wall of a graphite crucible. The crystalline structure of the samples was analysed in Raman spectroscopy and confirmed as 3C-SiC both in x-ray diffraction and x-ray photoelectron spectroscopy (XPS). The Raman spectra of the samples present a strong sharp peak located at 796.3 cm-1 with a full width at half maximum about 6 cm-1 and three weak peaks broadened around 1525.6, 1631.4 and 1719.1 cm-1, respectively. The former belongs to the transverse optical phonons of 3C-SiC, while the latter can be attributed to the second-order scattering. However, the longitudinal optical mode of 3C-SiC has not been found for our samples. An additional broadened peak at 532.2 cm-1 may imply the existence of some lattice defect in the samples, which is related to nitrogen introduced unintentionally into the lattice in the growth process and confirmed in XPS of N 1s binding energy centred at 400.9 eV.

For the intermetallic compound TiAl, the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations. In the calculations of the point defect properties of the TiAl alloy with this potential, it was shown that the thermal concentration of anti-site defects was higher than that of other point defects. With similar formation energies, five possible interstitial configurations were stable. This model was consistent with the embedded atom method or embedded defect method and adequate for simulation of defects in the TiAl alloy.