Lattice contracted AgPt nanoparticles

Lattice distortion in AgPt nanoparticles was studied using X-ray diffraction and other techniques. These nanoparticles show high catalytic activity in the reduction of p-nitrophenol and had a turn over frequency of 5.4 × 10(2) s(-1).     

基于扩展有限元法的颗粒增强复合材料静态及动态断裂行为研究

运用不含裂尖增强函数的扩展有限元法,分别研究了静态及动态载荷作用下颗粒增强复合材料的断裂行为.假定基体和颗粒都为线弹性材料并且绑定完好,研究了不同颗粒位置、数量对基体裂纹尖端断裂参数的影响.数值模拟结果清晰地显示了含刚性颗粒和柔性颗粒时不同的失效机制.结果同时证明论文采用的数值方法能够准确预报颗粒增强复合材料的断裂行为,也更易于被工程界所接受.     

Atmospheric CO_2 capture and photofixation to near-unity CO by Ti~(3+)-V_o-Ti~(3+) sites confined in TiO_2 ultrathin layers

To realize efficient atmospheric CO_2 chemisorption and activation,abundant Ti~(3+) sites and oxygen vacancies in TiO_2 ultrathin layers were designed.Positron annihilation lifetime spectroscopy and theoretical calculations first unveil each oxygen vacancy is associated with the formation of two Ti~(3+) sites,giving a Ti~(3+)-V_o-Ti~(3+)configuration.The Ti~(3+)-V_o-Ti~(3+) sites could bond with CO_2 molecules to form a stable configuration,which converted the endoergic chemisorption step to an exoergic process,verified by in-situ Fourier-transform infrared spectra and theoretical calculations.Also,the adjacent Ti~(3+) sites not only favor CO_2 activation into COOH*via forming a stable Ti~(3+)–C–O–Ti~(3+) configuration,but also facilitate the rate-limiting COOH~* scission to CO~* by reducing the energy barrier from 0.75 to 0.45 e V.Thus,the Ti~(3+)-V_o-TiO_2 ultrathinlayers could directly capture and photofix atmospheric CO_2 into near-unity CO,with the corresponding CO_2-to-CO conversion ratio of ca. 20.2%.     

聚焦光在亚表面损伤介质中的散射特性

针对光学元件的亚表面缺陷,结合基于激光共焦层析的亚表层检测方法,建立聚焦光束在亚表面损伤介质中的传输模型,并采用有限元分析方法,仿真研究K9玻璃光学元件亚表层缺陷对聚焦光束的散射调制特性,特别对颗粒状和微裂纹两类特殊缺陷的光学调制特性进行研究和分析,探索了波长、缺陷大小、缺陷折射率及缺陷方向对聚焦光束散射特性的影响规律,通过分析包含亚表面损伤缺陷信息的光场分布图和强度变化曲线,获得了亚表面损伤缺陷的信息,并对其进行评价。     

Fabrication and Characterization of Chitosan–Pea Protein Isolate Nanoparticles

Chitosan (CS) and pea protein isolate (PPI) were used as raw materials to prepare nanoparticles. The structures and functional properties of the nanoparticles with three ratios (1:1, 1:2 1:3, CS:PPI) were evaluated. The particle sizes of chitosan–pea protein isolate (CS–PPI) nanoparticles with the ratios of 1:1, 1:2, and 1:3 were 802.95 ± 71.94, 807.10 ± 86.22, and 767.75 ± 110.10 nm, respectively, and there were no significant differences. Through the analysis of turbidity, endogenous fluorescence spectroscopy and Fourier transform infrared spectroscopy, the interaction between CS and PPI was mainly caused by electrostatic mutual attraction and hydrogen bonding. In terms of interface properties, the contact angles of nanoparticles with the ratio of 1:1, 1:2, and 1:3 were 119.2°, 112.3°, and 107.0°, respectively. The emulsifying activity (EAI) of the nanoparticles was related to the proportion of protein. The nanoparticle with the ratio of 1:1 had the highest potential and the best thermal stability. From the observation of their morphology by transmission electron microscopy, it could be seen that the nanoparticles with a ratio of 1:3 were the closest to spherical. This study provides a theoretical basis for the design of CS–PPI nanoparticles and their applications in promoting emulsion stabilization and the delivery of active substances using emulsions.     

Some continuous dependence results on the complex Ginzburg–Landau equation

Continuous dependence on a modelling parameter are established for solutions to a problem for a complex Ginzburg–Landau equation. We establish continuous dependence on the coefficient of the cubic term, and also on the coefficient of the term multiplying the Laplacian. Copyright 2003 John Wiley & Sons, Ltd.     

On Bounded Positive (m,p)-Circle Domains

Let D be a bounded positive (m, p)-circle domain in ?². The authors prove that if dim(Iso(D)⁰) = 2, then D is holomorphically equivalent to a Reinhardt domain; if dim(Iso(D)⁰) = 4, then D is holomorphically equivalent to the unit ball in ?². Moreover, the authors prove the Thullen’s classification on bounded Reinhardt domains in ?² by the Lie group technique.     

Fabrication of an Anti-Reflective Microstructure on ZnS by Femtosecond Laser Bessel Beams

As an important mid-infrared to far-infrared optical window, ZnS is extremely important to improve spectral transmission performance, especially in the military field. However, on account of the Fresnel reflection at the interface between the air and the high-strength substrate, surface optical loss occurs in the ZnS optical window. In this study, the concave antireflective sub-wavelength structures (ASS) on ZnS have been experimentally investigated to obtain high transmittance in the far-infrared spectral range from 6 μm to 10 μm. We proposed a simple method to fabricate microhole array ASS by femtosecond Bessel beam, which further increased the depth of the microholes and suppressed the thermal effects effectively, including the crack and recast layer of the microhole. The influence of different Gaussian and Bessel beam parameters on the microhole morphology were explored, and three ASS structures with different periods were prepared by the optimized Bessel parameters. Ultimately, the average transmittance of the sample with the ASS microhole array period of 2.6 μm increased by 4.1% in the 6 μm to 10 μm waveband, and the transmittance was increased by 5.7% at wavelength of 7.2 μm.