A fast method for determining favourable orientation relationships and interface planes: Application to titanium–titanium hydrides transformations

The transformation of titanium into several hydride phases has been studied by transmission electron microscopy at the surface of an acid-etched titanium substrate designed for biomedical applications. Four different orientation relationships have been found between face-centred cubic TiH_2−ε (ε ≪ 1), face-centred tetragonal TiH and hexagonal close-packed Ti. A fast method based on the alignment of diffraction spots perpendicular to interfaces (Δg condition) is proposed, to account for the experimental orientation relationships and interface planes. Different paths leading to the formation of the two above-mentioned hydride phases have been thus identified. A mechanism of misfit relaxation has been observed and described.     

TiO2/ITO膜的液相沉积法制备及其用于4-氨基安替比林降解的光电催化活性

利用液相沉积（LPD）法在ITO表面制备TiO2薄膜。光电流和交流阻抗（EIS）测试表明,这种TiO2/ITO液相沉积膜具有良好的光电性能,对紫外光产生灵敏、快速的电流响应,在此膜电极上通过施加一定的阳极偏压可有效分离光生电子-空穴对。将TiO2/ITO膜用于4-氨基安替比林的光电催化降解研究,与其他方法相比,利用此液相沉积膜电极的光电催化技术对于4-氨基安替比林的降解具有明显的协同效果,适合于该污染物的降解处理。当外加阳极偏压为＋0.8 V,支持电解质Na2SO4浓度为0.1 mol/L,溶液pH为2.0时,0.1 mmol/L 4-氨基安替比林120 min的光电催化降解效率最高可达95%。     

The ternary system Na2O–ZnO–WO3: Compounds and phase relationships

The subsolidus phase relationships of ternary system Na₂O–ZnO–WO₃ have been investigated by X-ray diffraction (XRD) and differential thermal analyzer (DTA). All the samples were synthesized in the temperature range from 530 to 850 °C in air. There are one ternary compound and five binary compounds in the Na₂O–ZnO–WO₃ system, which can be divided into eight three-phase regions. The crystal structure of the ternary compound Na_3.6Zn_1.2(WO₄)₃ is determined by single-crystal structure analysis method. It belongs to triclinic system with space group and lattice constants a = 7.237 (5) Å, b = 9.172 (6) Å, c = 9.339 (6) Å and  = 94.920 (4)°, β = 105.772 (9)°, γ = 103.531 (8)°, Z = 2. DTA analyses indicate that the compound Na₂WO₄ is not suitable to be the flux for ZnO crystal growth below 1250 °C, since no liquidus was observed in the system before 1250 °C.     

Unusual spectroscopic properties of PPE/TiO2 composite and its sensor response to TNT

A composite from a broad bandgap polymer, poly(phenylene ethylene) (PPE), and nano-sized TiO₂ particles was found to be able to sense 2,4,6-trinitrotoluene (TNT) for TNT sensor. Fluorescence quenching induced by charge transfer from PPE to nano-sized TiO₂ was observed in toluene solution. At high TiO₂ composition, a strong exciplex band occurred at 550 nm. Under prolonged light irradiation at 400 nm, unusual fluorescence gains took place at 460 nm, companied with a very small change in the UV–vis absorbance. After 30 min light irradiation, the fluorescence at 460 nm reached a maximum, but the peak at 550 nm disappeared. This composite showed amplified sensor response to TNT compared to the pristine PPE film, which can be potentially used as sensing material for detecting TNT based explosives.     

A direct method for the crystallography of martensitic transformation and its application to TiNi and AuCd

A simple and straightforward method to obtain a complete set of twining planes and habit planes of martensitic crystals by using the crystallographic data is proposed under the bulk strain energy minimization hypothesis. This method can also be used to obtain the diffraction pattern corresponding to martensitic transformation forming the invariant planes. Applications to the cubic→trigonal and cubic→monoclinic martensitic transformation are presented. The results well explain the morphological differences between R-phase in TiNi and ζ′₂ martensite in AuCd.     

Si(100)衬底上(110)取向La_(2/3)Sr_(1/3)MnO_3薄膜的制备与性能

用脉冲激光沉积法在Si(100)衬底上制备了(110)择优取向的La2/3Sr1/3MnO3薄膜,研究了环境氧压对薄膜结晶度、取向、表面形貌和微结构的影响。结果表明:10Pa氧压下沉积的薄膜具有高结晶度的(110)择优取向,晶粒分布均匀,晶粒分布均匀,表面均方根粗糙度Rrms为1.35 nm。与无明显择优取向的薄膜相比,(110)择优取向的La2/3Sr1/3MnO3薄膜具有较高的饱和磁化强度(Ms)、金属-绝缘体相变温度(TM-I)和较低的电阻率(ρ)。     

Preparation of SO2-4/TiO2-WO3 solid superacid and its catalytic activity in acetalation and ketalation

SO2-4/TiO2-WO3 was prepared and its catalytic activity under different synthetic conditions was discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions are found that the mass fraction of H2WO4 used in the compound is 12.5%, the calcination temperature is 580℃, the calcination time is 3 h, and the soaked consistency of H2SO4 is 1.0 mol.L-1. Then SO2-4 /TiO2-WO3 was applied as the catalyst in the catalytic synthesis of eight similar important ketals and acetals under the optimum conditions and revealed high catalytic activity. On condition that the molar ratio of aldehyde/ketone to glycol is 1:1.5, the mass fraction of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 64.2%-95.1%. Moreover, it can be easily recovered and reused.     

Thin nanocrystalline TiO2–SnO2 sprayed films: Influence of the dopant concentration,substrate and thermal treatment on the phase composition and crystallites sizes

Thin nanocrystalline TiO₂–SnO₂ films (0–50 mol% SnO₂) are coated on quartz and stainless steel substrates by spray pyrolysis method. The synthesized films are investigated by XRD, Raman spectroscopy and XPS.The diffraction peaks of anatase phase fade while the peaks of rutile phase appear in the X-ray profiles with increasing of the treatment temperature and the content of SnO₂ in the sprayed films. It is found that SiO₂ coming from the quartz substrate stabilizes the anatase phase up to 700 °C. A more pronounced crystallization of rutile is registered with the films deposited on stainless steel substrate, which probably is caused by combined effect of SnO₂ doping and penetration of iron and chromium from the substrate inside the films.Dopant concentration (SnO₂) influences the size of the crystallites of the titania films deposited on quartz substrates The size of crystallites in the titania films decreases from 45 to 25 nm with increasing of SnO₂ amount.The SnO₂ amount does not affects substantially the size of crystallites (about 23 nm) for the films deposited on stainless steel.     

Preparation of Fe3O4@C@TiO2 and its application for oxytetracycline hydrochloride adsorption

The magnetic Fe₃O₄@C@TiO₂ microspheres with multilevel yolk-shell structure were successfully prepared by combining sol-gel and simple hydrothermal methods.The features of the as-obtained Fe₃O₄@C@TiO₂ microspheres were investigated by Fourier transform infrared(FTIR) spectra,scanning electron microscopy(SEM),powder X-ray diffraction(XRD),N₂ adsorptiondesorption measurements and transmission electron microscopy(TEM).Fe     

Computed depth profile method of X-ray diffraction and its application to Ni/Pd films

This paper develops a method that uses parallel beam X-ray diffraction (XRD) for profiling structure and phase distributions along with the depth. This method was used to characterize the Ni/Pd thin film sample and to obtain the phase depth profile. In the data analysis procession, the non-negative least square (NNLS) algorithm was introduced to resolve the ill-posed inverse problem that emerged in the solving procession. The grains with same crystallographic orientation were measured when the incident angles varied in the designed diffraction manner and the influence of the texture in the films was avoided properly. It should be noticed that this method is employed for the first time to analyze a system containing more than two phases.     

轧制过程AGC系统的建模新方法及应用

提出了轧制过程ＡＧＣ系统的一种建模新方法,介绍了其在某冷连轧机上的应用及效果,带钢厚度波动从４５μｍ减小到２０μｍ．     

热变形的固有应变预测法及实例

阐述了以固有应变为基础的弹性板单元有限元残余变形预测法.通过金属结构的焊接变形的预测和船板的线状加热弯曲成形变形计算的实例,验证了固有应变为基础的弹性板单元有限元残余变形预测法在热加工过程中应用的可行性.     

A time-of-flight mapping method for laser ultrasound guided in a pipe and its application to wall thinning visualization

Piping systems in nuclear power plants (NPPs) are susceptible to flow-accelerated corrosion (FAC) that results in local wall thinning of the piping system. FAC can cause severe piping failure such as leakage and rupture. In this study, a reliable ultrasonic time-of-flight (ToF) mapping system in the pipe is proposed with the goal of improving ultrasonic NPP pipe inspection. The system consists of a high-speed laser ultrasonic scanning system (50 mm/s at intervals of 0.5 mm) and two ultrasonic sensors. The ToF mapping algorithm uses mode identification based on wavelet transform, an automatic threshold setting method based on the statistics of the spatial noise map, and two-dimensional (2-D) ToF extraction based on the threshold crossing time method. The Lamb-like waves guided in the wall of a stainless steel (SUS) straight pipe were simultaneously interrogated by the proposed two-channel laser ultrasonic system. The proposed ToF mapping algorithm enabled the generation of a smooth ToF distribution within the beam incidence angle of ±60° in the curved surface of the pipe. Then a ToF mapping method was applied to a wall-thinned pipe, and an ultrasonic wave propagation movie was generated to help understand the complex ultrasonic propagation pattern. Based on an understanding of the ToF change in the wall-thinned region, and on the mode collapse and attenuation that occurred because of the ultrasonic bottleneck phenomenon, the wall-thinned region was evaluated. Since this method allows in-situ and automatic field inspection, it can contribute to NPP pipe health management.     

A thermodynamic database of the Al-Ga-In-P-As-Sb-C-H system and its application in the design of an epitaxy process for III–V semiconductors

With the help of Thermo-Calc software and based on the thermodynamic database of the Al-Ga-In-P-As-Sb-C-H system, the compositional spaces under conditions of different temperatures and pressures can be calculated and analyzed in the cases of stable, metastable equilibria, or irreversible reactions. Compared with traditional methods, more information can be obtained from the present calculation. Such information is useful to computer-assisted design for metalorganic vapor phase epitaxy (MOVPE) processing of III-V semiconductors.     

A thermodynamic database of the Al-Ga-In-P-As-Sb-C-H system and its application in the design of an epitaxy process for III–V semiconductors

With the help of Thermo-Calc software and based on the thermodynamic database of the Al-Ga-In-P-As-Sb-C-H system, the compositional spaces under conditions of different temperatures and pressures can be calculated and analyzed in the cases of stable, metastable equilibria, or irreversible reactions. Compared with traditional methods, more information can be obtained from the present calculation. Such information is useful to computer-assisted design for metalorganic vapor phase epitaxy (MOVPE) processing of III-V semiconductors.     

The quaternary system B2O3-PbO-SiO2-ZnO: Thermodynamics and phase diagram

We evaluated the six binary phase diagrams, B₂O₃-PbO, B₂O₃-SiO₂, B₂O₃-ZnO, PbO-SiO2, PbO-ZnO, and SiO₂-ZnO, to obtain a consistent picture for the quaternary system B₂O₃-PbO-SiO₂-ZnO. We used all the available thermodynamic data: enthalpies of mixing, activity data, complete phase diagrams, and miscibility gaps. The agreement between the various sets of data is good. We also calculated the enthalpy of formation of the ternary compound 5PbO-B₂O₃-SiO₂. Δ_fH/R of 1/8 [5PbO-B₂O₃-SiO₂] =-(2.104 ± 0.057) kK.     

g-C3N4/MoS2纳米片异质复合物的球磨法制备及可见光催化性能研究

采用球磨法制备g-C₃N₄/MoS₂纳米片异质复合物,运用X-射线衍射仪、高分辨透射电镜、紫外可见漫反射光谱和荧光发射光谱对异质复合物的结构和形貌进行了表征。结果表明：MoS₂纳米片可进入g-C₃N₄的层间形成异质复合物。以罗丹明B为模拟污染物,在可见光照射下考察了复合物的光催化特性。结果显示,含有2%的MoS₂纳米片与g-C₃N₄形成的异质复合物在120min内对罗丹明B降解率为98%,其降解动力学常数是体相g-C₃N₄为的4.3倍。g-C₃N₄/MoS₂纳米片异质复合物具有十分优良的光催化特性。其催化活性的提高主要归因于光生电子和空穴的有效分离和传输,并根据光捕获实验提出复合物可能的光催化机理。     

A facile method for fabrication of nano-structured Ni-Al2O3 graded coatings: Structural characterization

Powder charges of micron-size Ni and Al₂O₃ were utilized to deposit nano-structured Ni-Al₂O₃ composite coatings on an aluminum plate fixed at the top end of a milling vial using a planetary ball mill. Composite coatings were fabricated using powder mixtures with a wide range of Ni/Al₂O₃ mass ratio varying from 1:1 to plain Ni. XRD, SEM and TEM techniques were employed to study the structural characteristics of the coatings. It was found that the composition of the starting mixture strongly affects the Al₂O₃ content and the microstructure of the final coating. Mixtures containing higher contents of Al₂O₃ yield higher volume fractions of the Al₂O₃ particles in the coating. Though Ni-Al₂O₃ composite coatings with about 50% of Al₂O₃ particles were successfully deposited, well-compacted and free of cracks and/or voids coatings included less than 20% (volume fraction) of Al₂O₃ particles which were deposited from powder mixtures with Ni/Al₂O₃ mass ratios of 4:1 or higher. Moreover, mechanical and metallurgical bondings are the main mechanisms of the adhesion of the coating to the Al substrate. Finally, functionally graded composite coatings with noticeable compaction and integrity were produced by deposition of two separate layers under identical coating conditions.