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Three-dimensional/two-dimensional (3D/2D) rare earth Ln3+ (Ln = Er or Eu)-doped BiOBr wrapped with reduced graphene oxide (Bi-Ln/rGO) was obtained via a two-step solvothermal–hydrothermal process. The doping of Ln3+ and the construction of heterojunction between 3D Ln3+-doped BiOBr microspheres and 2D rGO nanosheets were beneficial to the wide absorption of visible light and the efficient separation of photoinduced electrons and holes, further improving the photocatalytic activity of Bi-Ln/rGO composites for RhB photodegradation. The photocatalytic activity of Bi-Ln/rGO was higher than those of pure BiOBr, Ln3+-doped BiOBr, and BiOBr/rGO. The radical-trapping experiments on active species indicated that h+ and ·O2− were mainly responsible for the photodegradation of RhB. The mechanism of the enhanced photocatalytic performance was proposed on the basis of radical-trapping experiments on active species.

In this study, the magnetically recyclable Fe3O4@C/BiOBr heterojunction with enhanced visible light-driven photocatalytic ability was obtained by two-step solvothermal method. The phase, morphology, and structure of the samples were investigated by XRD, FESEM, HRTEM, and XPS. The Fe3O4@C/BiOBr heterojunction was composed of Fe3O4@C sphere and BiOBr microsphere with diameters of 200 nm and 1000 nm, respectively. The photocatalytic performance of Fe3O4@C/BiOBr composite for RhB was examined under visible light irradiation. The photocatalytic activity of Fe3O4@C/BiOBr composite was much higher than that of pure BiOBr and Fe3O4@C. After 35 min of irradiation, 97% of RhB could be removed with the Fe3O4@C/BiOBr photocatalyst. Based on radical trapping experiments of active species, the mechanism of enhanced photocatalytic performance was proposed. In addition, the superparamagnetic property of the photocatalyst not only allows its easy recyclability by an external magnetic field but also maintains high photocatalytic activity after five cyclic experiments.

Indium tin oxide (ITO) anodes were deposited by an improved magnetron sputtering technique (energy filtrating magnetron sputtering technique, EFMS) for top-emitting organic light-emitting diodes (TOLEDs). The phases, surface morphologies and optical properties were examined by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM) and spectroscopic ellipsometer. The sheet resistances were measured by the sheet resistance meter. The electrical properties were tested by the Hall measurement system. The electro-optic characteristics were examined by a special home-made measurement system. Results indicated that ITO anode deposited by EFMS had a more uniform and smoother surface with smaller grains. ITO film was prepared with the electrical property of the lowest resistivity (4.56 × 10 −4 Ω cm), highest carrier density (6.48 × 10 20 cm −3 ) and highest carrier mobility (21.1 cm 2 /V/s). The average transmissivity of the ITO film was 87.0% in the wavelength range of 400–800 nm. The TOLEDs based on this ITO anode had a lower turn-on voltage of 2 V (>0.02 mA/cm 2 ), higher current density of 58.4 mA/cm 2 at 30 V, higher current efficiency of 1.374 cd/A and higher luminous efficiency of 0.175 lm/W. The possible mechanism of the technique was discussed in detail.

报道了一种激光二极管（LD）端面连续抽运的高重频、高光光效率电光调Q Nd：YVO4激光器。采用RbTiOPO4（RTP）晶体对作为调Q元件，通过减小热效应和模式匹配技术，实现了高效率的高重频窄脉宽1 064 nm脉冲激光输出。一方面采用低吸收系数的914 nm波长抽运Nd：YVO4晶体，使晶体内热分布均匀，从而获得高量子效率的同时减小了热效应影响。另一方面通过优化泵浦光斑半径，实现泵浦光和振荡光好的模式匹配。在重频200 kHz时，获得了最高输出功率16 W，脉宽9 ns，单脉冲能量80 J，光束质量M21.2的稳定脉冲激光，泵浦吸收功率31 W，对应的光光转化效率为51.6%。据笔者所知，这是RTP电光调Q实现的最高效率的脉冲激光器。

用固相反应法制备了RBaCo 2 O 5+ δ (R=Y、Dy、Gd、Pr、Nd、Sm和Eu)系列陶瓷. 用标准四探针法测量了它们从室温到600℃之间的电阻率变化. 在温度较低时, 它们的电阻率都随着温度的升高而减小, 显示为半导体特征. 当电阻率在某一温度达到最大值后, 电阻率开始随着温度升高而缓慢增加, 显示为半金属特征. 进一步研究了RBaCo 2 O 5+ δ 系列陶瓷在高温恒温时的电阻率随着环境气氛的变化情况. 结果表明RBaCo 2 O 5+ δ 陶瓷是一类潜在的氧阻传感器材料, 并且它们的响应速率从快到慢顺序是YBaCo 2 O 5+ δ > DyBaCo 2 O 5+ δ > GdBaCo 2 O 5+ δ > PrBaCo 2 O 5+ δ > NdBaCo 2 O 5+ δ > SmBaCo 2 O 5+ δ > EuBaCo 2 O 5+ δ . 以YBaCo 2 O 5+ δ 陶瓷为例, 在700℃恒温时, 当从氧气氛切换到氮气氛时, 由于晶格中氧的脱附导致电阻率先是快速上升, 然后缓慢上升, 并在90 s内达到最大平衡值. 反之, 当从氮气氛切换为氧气氛时, 由于氧的吸附, 电阻率迅速降低, 约30 s内达到最小平衡值.

In this communication, the morphology of double branched anodic aluminum oxide (AAO) templates from linear down or step down function of anodizing voltage is discussed. The interconnected AAO film is obtained when the thin pore wall at the final branched channels is dissolved by chemical etching. The three-dimensional interconnected porous carbons are fabricated by carbonization of polyimide film which is negative replicated from the layered interconnected AAO template. Keywords: Anodic aluminum oxide, Branch, Interconnected, Carbon

Densification behaviour and microstructural evolution of TiO 2 /CAS (CaO-Al 2 O 3 -SiO 2 )-incorporated alumina has been investigated systematically. The experimental results show that TiO 2 can greatly enhance the densification rates of alumina but trigger severely abnormal grain growth (AGG) at 0.60 wt%. On the other hand, small amounts of CAS can effectively inhibit abnormal grain growth, but provoke an abnormal densification owing to the formations of in situ pores left by liquid phase. With additional 0.50 wt% of CAS incorporated into 0.60 wt% TiO 2 -doped sample, the aspect-ratios of anisotropic growth grains increase by reduced growth rates of flat boundaries, accomplished by basal planes much smoother and straighter. This microstructure subsequently disappears when CAS incorporation is up to 4.0 wt%, substituted by that with low aspect-ratio and fine-equiaxed grains. Such occurrences are discussed in term of levels of liquid phase and 2-dimension (2-D) nucleation processes.

The light scattering is found to have a great influence on the transmission spectra of photonic crystal of anodic alumina. The incident light is diffracted by a regular array of branched channels or pores obeying the Bragg law. The intensity of transmission light decreases with the increasing etching time because of the increasing porosity or enlarging scatterers. The variation of intensity and widths of dips in transmission spectra of the porous alumina membrane versus the incidence angle shows the quite different characteristics from the other photonic crystal such as colloidal photonic crystal.

In order to save vehicle weight and protect environment, lightweight materials such as aluminum alloys have been widely used in the automotive industry. As a solid state jointing technique, refill friction stir spot welding (RFSSW) process is expected to apply to join automobile body parts made of aluminum sheet, because of its advantages. The present paper investigated the material flow in the plunge stage during RFSSW process by smoothed particle hydrodynamics (SPH) numerical simulation method. Material flow patterns and flow velocity was analyzed. The research results can provide guidelines for process analysis and welding quality improvement of RFSSW process.

The expansion of low heat Portland slag cement with slight expansion (LSE cement) was studied by XRD, SEM and test methods for strength and expansion. Results indicated that under the condition of 4.5–5.0% MgO in clinker and 2.8–3.4% SO 3 in cement, ettringite expansion and brucite expansion produced by periclase hydration in the paste had continuity, entirety and stability. Periclase hydration in the paste started at about 60 days and was completed up to 2000 days and ettringite was stable from 3 to 2000 days. At the ages of 28, 90, 365, 730 and 2000 days the expansion of the paste reached 0.08–0.13%, 0.09–0.14%, 0.12–0.17%, 0.13–0.18% and 0.15–0.21%, respectively. At the ages of 2, 28 and 180 days the autogenous volume deformation of mass concrete made out of LSE cement was positive and was 0.0042%, 0.0050% and 0.0066%, respectively and the prestress of the concrete with 2.0% steel bar content was 0.069, 0.060 and 0.082 MPa, respectively. The results suggest that using this cement in mass concrete may compensate for a part of its thermal shrinkage and autogenous shrinkage.

Pure and Ti-doped WO3 thin films prepared by RF (radio-frequency) magnetron at room temperature were determined by XRD, Raman and SEM to analyze the micro-structure and the morphology of the films. In addition, electrochemical workstation and UN-Vis-NIR spectrophotometer were used to measure their cycling stability and optical property. Research results showed that Ti doping had little interference with the surface morphology and optical constants, but the film crystallization temperature could be increased by Ti doping. Electrochemical test results showed that Ti doping could improve reversibility of ion injection and extraction, and improve cycling performance of films. Meanwhile, the switching speed and optical modulation performance of films were enhanced. In detail, the switching time of colored and bleached states were shortened from 9.8 s and 3.5 s to 8.4 s and 2.7 s, respectively. Therefore, Ti doped WO3 thin films has better electrochromic properties.

Novel anodic aluminium oxide (AAO) films and hollow nanostructures were synthesized via a simple electrochemical and chemical etching route; fluctuating nanotube growth inside AAO film fabricated under ultra-high voltage was considered to be the main reason for the formation of such new structures.

Nanocrystalline V2O5 thin films were reactively radio-frequency magnetron-sputtered under optimal deposition parameters. Their electrochemical and electrochromic characteristics were investigated by cyclic voltammetry and in-situ monochromatic transmittance measurements. Upon lithium intercalation, V2O5 thin films showed a double electrochromic behavior depending on the wavelength and the intercalation extent. X-ray photoelectron spectroscopy results showed that part of the V5+ in V2O5 was reduced to V4+ during the Li+ intercalation process.

Ni-based single crystal line alloy is constituted with γ phase and γ' phase in the form of coherency. Since an indenter for two-phase coherent structure is bigger than the usual nano-scale indenter, the press location of indenter may be unclear in nanoindentation simulation. Both γ phase and γ' phase may be pressed initially, and the mechanical properties shown are different because of the initial press locations. The nanoindentation of Ni-based single crystal line alloys is simulated by molecular dynamics method. Two models are used to study about the hardness in [001] crystal orientation, one is the model γ /γ' with the initial indentation on γ phase, and the other is the model γ'/γ with the initial indentation on γ' phase. The influence of misfit dislocation at (001) interface on nanoindentation of the two models is analyzed using a center-symmetry parameter. Results show that the misfit dislocation shape of the two models are different after relaxation. Lomer-Cottrell dislocation occurs on (001) interface in the γ'/γ model. Before 0.930 nm press depth is reached, there is little change in the (001) interface misfit dislocation of the two models. Relationship between press load and press depth is similar for the two models, and it is the same in the relationship between hardness and press depth. After press depth reaches 0.930 nm, the misfit dislocation at (001) interface for model γ'/γ grows big, which results in a smaller press load and a smaller hardness computation in the model γ'/γ than that in model γ /γ'. When the press depth reach 2.055 nm, we find only a small amount of dislocations in γ phase that can go into γ' phase since the misfit dislocation at (001) interface in model γ /γ' hinders the process. However, none of dislocations can go into γ phase because of the prevention caused by Lomer-Cottrell dislocation at the (001) interface in the model γ'/γ . That means the Lomer-Cottrell dislocation reinforces the material obviously. So the press load in model γ'/γ grows faster than that in model γ /γ'.

Nanoindentation made by diamond indenter on pure Ni and the /'-phase in a Ni-base single-crystal superalloy is simulated respectively with molecular dynamics method. Elasticity modulus and hardness of the two models are calculated. Initiation and growth of dislocations and the influence of misfit dislocations of /'-phase in Ni-base single-crystal superalloy at different indentation depths are analyzed with center symmetry parameter. Results show that the relationship between indentation load and depth for the two models is similar when the indentation depth below 0.641 nm, indicating that the misfit dislocation on interface little affects the indentation. When the indentation depth reaches 0.995 nm, the dislocation nucleation can be found in misfit dislocations and the crystals that have slipped along {111}-oriented crystal surface in -phase. As a result, the indentation load of the latter model decreases and is smaller than that in pure Ni model before the indentation depth reaches 1.487 nm. When the indentation depth reaches 1.307 nm, owing to the inhibition caused by misfit dislocations at the interface, the indentation load for the /'-phase model in Ni-base single-crystal superalloy increases rapidly.

The machined workpiece has high mechanical storage energy because of the defect structures formed in nanocutting and their evolution from high energy state to the low energy state by adjusting atom positions automatically is called surface-energy aging. The effect of surface-energy aging on the surface properties of monocrystalline silicon workpiece is analyzed by Monte Carlo simulations of machined surface. It is shown that the surface-energy aging effect can increase the surface roughness and the degree of order of damaged layer, however reduce the residual stress and the average potential energy of workpiece. Amorphous silicon structure in metamorphic layer decreases and recrystallization phenomenon occurs in the surface-energy aging process. It is found that some β-Si phase structures and BCT5-si phase structures transform into the diamond cubic structure of Si in the surface-energy aging process. Surface-energy aging effect has a great influence on the surface properties of the machined surface of monocrystalline silicon workpiece, and can improve the mechanical properties of micro/nanostructures.

The intrinsic mechanisms of aluminium anodization processes have been investigated in detail by analyzing the anodization current density (ia). The characteristics and general chemical reactions of mild anodization (MA) and hard anodization (HA) have been discussed, and the avalanche of the electronic current is considered to be the main reason to trigger the HA process. Moreover, the formation mechanisms of the maximum anodization voltage (Umax) in different electrolytes have been studied in detail, and it is found that the electrolyte dissociation constant can have a direct impact on the avalanche electronic current density (ie) and Umax. Based on the above arguments, the electrolyte modifying process has been investigated. In addition, the representative microstructural morphologies of anodic aluminium oxides (AAO) together with their intrinsic formation mechanisms have also been studied.

Nanoporous anodic aluminium oxide (AAO) films with a large-range tunable interpore distance (Dint) and unique microstructures have been fabricated by high voltage anodization (140–400 V) in 0.3 M oxalic acid electrolyte. The influences of anodization conditions (e.g., anodization voltage (Ua) and current density (ia)) on the microstructures of AAO films have been investigated in detail. Experimental results show that there is a linear relationship between Ua and Dint under relatively low Ua. With the increase of Ua, the influences of ia and dehydration of aluminium hydroxide on the Dint may not be ignored, thus resulting in a nonlinear relationship between Ua and Dint. When the anodization is performed at an excessively high Ua of 400 V, an interesting competitive growth of nanochannels inside the AAO film tends to occur, thus forming an AAO film with unique nano/micro morphology at the barrier layer side.

Alumina nanotubes (ANTs) with unique fusiform morphologies were synthesized via a simple electrochemical route; the fluctuation of the electronic current density during the anodization process is considered to be the main reason for the formation of such new alumina nanostructures.

Using density functional theory, we study high hydrogenated zigzag single-walled carbon nanotubes from (7,0) to (11,0). Two structure transitions are classified: type A is a metallic transition and type B is a “semiconductive transition according to the energy band structure. The charge density transforms only at the C-C bonds without hydrogenated sites. The sp3 hybridization is mainly enhanced for all the C-C bonds in the vertical axial direction for type-A configurations, and the sp3 hybridization mainly increases for all C-C bonds along the axial direction for the type-B case.

A competitive model accounting for the growth of branched channels inside AAO membranes is proposed in this paper. According to this model, two types of competition which originate from the non-uniform thinning of stem channel barrier layers result in the tree-like morphology of branched channels. Furthermore, competitive growth can be suppressed or eliminated by thinning the barrier layers of stem channels before the second step anodization. Experimental results have confirmed this growth model and indicate that controllable uniform branched channels on a large scale can be obtained by the assistant of moderate chemical etching to adjust the starting thickness of the barrier layers.

Multiferroic ceramics of Bi 5 Fe 1- x Co x Ti 3 O 15 ( x =0.0—0.6) are synthesized by the conventional solid state reaction, and their microstructure,magnetic and ferroelectric properties are investigated. X-ray diffraction patterns show that a four-layer Aurivillius phase is formed in each sample with a suggested structural transformation at heavy doping of Co ions. The Raman results demonstrate that Co ions enter into the lattice,occupy the B -sites in the BFCT- x and have an effect on the order occupancy of cations at B sites. It is found that the Co ion modification induces remarkable ferromagnetism (FM) at room temperature with a greatest remanent magnetization (2 M r) of 2.3 memu/g at x =0.5,which is three orders of magnitude larger than that of Bi 5 Ti 3 FeO 15 (BFTO). All samples with Co doping have ferroelectricity (EM). The remanent polarization (2 P r) reaches a value of 11 μC/cm 2 at x =0.1,which is about 38.2% higher than that of BFTO,and then decreases when 0.2≤ x ≤0.4 and increases again at x =0.5 and 0.6. Of all materials,the sample of x =0.5 is best in both good FE and FM.

By adjusting the anodization voltage periodically in the process of electrochemical oxidation of aluminum and subsequent chemical etching, anodic aluminum oxide membranes with a dual periodic layer-by-layer structure are prepared. Optical transmission spectra analyses prove that the dip position is dependent on the thickness of the layer and can be easily adjusted by the anodization voltage according to the Bragg–Snell formula. This result implies that the position and width of the stop band and the pass band in the visible and near infrared wavelength region can be designed and prepared arbitrarily. It is expected that these kinds of anodic aluminum oxide membranes may find applications in the fabrication of various optical devices.

A novel model, which indicates that the growth of branched channels in anodic alumina oxide membranes is different from what has been reported before, has been established in this communication.

The amorphous carbon nitride films were prepared by dc magnetron sputtering first and then were heat－treated at high temperature.DTA XRD Auger spectroscopy wer e used to study the difference of composition structure before and after heat－t reatment.The results showed that crystallization occurred at 1186℃.Heat－treatm ent can induce the crystallization of carbon nitride and the diffraction peaks a ppeared in the XRD pattern.The results of Auger spectroscopy also showed that th ere existed SiCN－riched area and the content of N decreased.