Engineering the Structure of Mesoporous Bioactive Glass Microspheres by the Surface Effect of Inverse Opal Templates and Temperature

The interactions of ions and molecules with material surface are highly dependent on the surface properties of the material. Therefore, the distribution of ions or molecules near the material surface may be affected by the surface properties. This phenomenon can be significant enough for controlling the structure of a material synthesized in the sub‐micrometer scale confinement space of a template. This work confirms that inverse opals are perfect templates for offering confinement space, while their different surface properties can strongly affect ion and block copolymer distribution in the confinement space. This surface effect principle can be used for the controlled synthesis of colloids with complex composition. As an example, four kinds of mesoporous magnetic bioactive glass colloids with ordered mesopores, core–shell structure, open surface pores, or disordered mesopores are prepared by using polystyrene and carbon inverse opal templates. This work reveals that inverse opal templates possess great advantage in controlled synthesizing colloidal structures due to their surface effect on ions and molecules and confinement space.     

Generated output increase control with consideration of the influence of wake for wind farm

Presently, many wind turbine generators (WTGs) are connected to the power grid. While the penetration of wind power to the power system is increasing, FIT price is decreasing. Therefore, wind generation companies want to increase the electric power output from wind farms (WFs). In this article, we propose a control technique to reduce the influence of the wake by changing a power coefficient of each WTG in a WF for the purpose of improving electric power output of WFs. We showed the optimization technique of a power coefficient of each WTG and the effect of reducing the influence of the wake using measurement data from WFs. In addition, we formulated the wake effect as a function of distance between WTGs. We verified 1% improvement of generated energy in a year compared to the conventional control method by simulation. Furthermore, we quantified the improvement of generated energy output, using the distance between WTGs and the occurrence rate of the direction of the wind as a variable.     

角度自适应离散纵标输运计算方法

精确的屏蔽计算方法是核装置辐射屏蔽设计的重要基础，离散纵标法(SN)是主要的屏蔽计算方法之一。本文基于价值理论的目标导向与角度自适应相结合的方法，有效地减弱了角度的离散误差。求解输运共轭方程获得目标函数的重要性分布，采用局部角度离散误差与目标函数的重要性加权，产生后验误差估计，为角度自适应过程提供判断依据。角通量密度的映射采用多项式权重法和球谐函数拟合法。数值结果表明，对于具有直孔道或曲折孔道的屏蔽问题，在相同精度下离散角度数减少了1～2个数量级，极大地减少了计算量。角度自适应方法以较少的离散方向获得了准确的计算结果，有效地减弱了角度离散误差对屏蔽计算精度的影响。     

Translation speed measurements of hydrogen,helium, and argon field-reversed configurations in the central cell of a KMAX mirror device

A series of experimental results of field-reversed configurations (FRCs) on a KMAX (Keda Mirror with AXisymmetricity) tandem mirror machine are reported. Single-side FRC translation processes with three different gas species were measured by avalanche photodiodes. Consistent with the theoretical prediction, the measured FRC speeds were inversely proportional to the square root of the ion mass. However, the speeds of the hydrogen FRC increased even in a uniform magnetic field region while the speeds of the helium and argon FRCs decreased. Possible mechanisms are discussed. The speed of the second pass due to the reflection of the mirror fields was found to be ∼1/3 of the first pass speed. The internal magnetic fields were measured for a colliding-merging argon FRC, and the results show that, even for very slowmoving FRCs, merging can occur.     

Lead-free sodium niobate nanowires with strong piezo-catalysis for dye wastewater degradation

In this work, the hydrothermally-synthesized sodium niobate nanowires were used to decompose Rhodamine B dye solution through the piezo-catalytic effect. With the sodium niobate catalyst, a high piezo-catalytic degradation ratio of ～80% was achieved under the excitation of vibration for the Rhodamine B dye solution (～5?mg/l). These active species in the catalytic process, hydroxyl radicals and superoxide radicals with the strong oxidation ability, were also observed, which confirmed the key role of piezoelectric effect for piezo-catalysis. The piezo-catalysis of sodium niobate nanowires provides a high-efficiency and reusable tool in application in depredating the dye wastewater.     

Ultrashort pulse-induced elastodynamics in polycrystalline materials. Part I: Model validation

The coupled thermal-mechanical response of a polycrystalline metallic film in response to ultrafast optical impingement is investigated. The thermo-elastodynamics formulated in the article considers laser absorption along the axial direction and thermal diffusion along the radial direction to account for the normal and shear stresses initiated by the rapid heating. The generalized formulation incorporates a two-step hyperbolic temperature model that characterizes the energy transport of electrons and lattices as finite in velocity. The coupling of thermal and mechanical fields is established through considering the energy dissipated in the form of propagating thermo-mechanical disturbances. The thermo-elastodynamical response of the polycrystalline film is found to be a strong function of the electron heat capacity that is also temperature-dependent. In addition, grain size effects due to film surface and grain-boundary scatterings are found to impact several thermophysical properties of the material. The impact of the energy transport of electrons is particularly prominent when the thickness becomes comparable with the electron mean-free-path. A staggered-grid finite difference scheme is followed to simultaneously resolve the coupled thermo-elastodynamical responses using an axisymmetric model. The time variation of the normalized electron temperature of a single crystalline gold film derived from the generalized model is favorably examined against published physical data, thus demonstrating the feasibility of the formulation in depicting the electron transport dynamics in response to non-ablating ultrafast irradiation.     

Synthesis conditions effect on the of photocatalytic properties of MnWO4 for hydrogen production by water splitting

This work aims to study the synthesis conditions effect on the photocatalytic properties of manganese tungstate (MnWO₄) for H₂ production by the water splitting reaction under visible light irradiation. This is achieved by relating the materials characterization and photocatalytic evaluation of MnWO₄ at different synthesis conditions. MnWO₄ was synthesized through a precipitation reaction between Mn²⁺ and (WO₄)^2- ionic species, while adding oleic acid (OA) as surfactant at two concentrations (0.1% and 1% V) and using three different stirring methods: magnetic stirring (AM), ultrasound (US) and high-shear stirring (UT). Characterization was carried out by TGA, XRD, BET surface area, UV–Vis spectroscopy and FESEM. XRD patterns confirm the wolframite structure of MnWO₄. BET surface area increased by using UT stirring. UV–Vis spectroscopy results revealed indirect transition Eg values of ≈2 eV, favorable for the MnWO₄ photoactivation under visible light irradiation. During the photocatalytic evaluation, sample 1%-UT produced the highest H₂ amount among all samples with a value of 72 μmolH₂g⁻¹, which was far higher compared to WO₃, which was taken as a reference photocatalyst.     

Synergistic effect of iodide ions and bark resin of Schinus molle for the corrosion inhibition of API5L X70 pipeline steel in H2SO4

The synergistic effect of bark resin of Schinus molle (BRSM) and iodide ions in 0.5 M sulfuric acid has been studied for the first time by potentiodynamic polarization and electrochemical impedance spectroscopy measurements; also, the surface morphology has been analyzed by scanning electron microscopy–energy-dispersive X-ray spectroscopic analysis in the present work. The results show that the BRSM and iodide ions have an evident synergistic inhibition effect in a 0.5-M sulfuric acid solution. The adsorption of the BRSM/iodide ion system follows the Langmuir adsorption isotherm and acts as a mixed-type inhibitor in sulfuric acid. The BRSM/iodide ion system is an effective inhibitor for API5L X70 pipeline steel in the 0.5-M sulfuric acid solution. The maximum percentage inhibition efficiency is equal to 99% at 1 g/L BRSM + 2 mM KI.     

综放面本煤层预抽瓦斯的治理技术

为了极大限度地提高本煤层预抽效果，以马兰煤矿为研究对象，针对目前马兰煤矿的瓦斯赋存情况和现阶段所采取的抽放措施，从抽放钻孔的孔径、孔深、布置方式、封孔质量和增加煤层透气性等方面进行探索。实践表明，以上方法的运用，能够有效地提高本煤层预抽抽放效果，保证工作面安全生产。