Rapid organism degradation function of Fe-based alloys in high concentration wastewater

The treatment of high concentration organic wastewater using Fe-based alloys in the Fenton-like system was investigated. The removal rate of COD by using the Fe₇₈Si₉B₁₃ metallic glass (MG) reached 85%, about 30% and 40% higher than that by the Fe₇₈Si₉B₁₃ crystalline alloy (CA) and by the traditional material Fe⁰ used in Fenton-like system, respectively. The treatment result by the Fe₇₈Si₉B₁₃ MG was more than 65% higher and 50 times faster than that of the traditional aeration process with the same addition of Fe⁰. It has been proved that the Fe₇₈Si₉B₁₃ MG played an excellent catalytic activity in the oxidative degradation of organic compounds, and its microstructure transformation during the corrosion process promoted the degradation efficiency of the wastewater treatment process.     

Synthesis,Crystal Structure,Magnetic Properties of a Manganese(II) Coordination Polymer with Double-Helix Chains

Abstract  

A new heterocyclic carboxylate ligand, 5-(4′-pyridyl)-3-methyl-benzoic acid (Hpmba), was synthesized to construct a Mn(II) coordination polymer, namely [Mn(pmba)₂] _n (1). Complex 1 crystallizes in monoclinic space group C2/c, with a = 17.44(2), b = 17.040(12), c = 8.680(15) ?, β = 111.258(13), V = 2404(5) ?³, and Z = 4. Single-crystal X-ray diffraction studies show that complex 1 has a 3D metal-organic supramolecular framework consisting of double helical chains. Magnetic studies for complex 1 show antiferromagnetic coupling between the nearest Mn(II) ions, with g = 2.11 and J = −10.1 cm⁻¹.     

Effects of graphite additive on dielectric properties and microwave absorption properties of zinc-containing foam glass

This paper reports effects of graphite additive on dielectric properties and microwave absorption performances of zinc-containing foam glasses. Changes of pore structure of porous glass are analyzed. One-dimensional zinc oxide crystal whiskers on walls of foam glass are observed. With the graphite additive increases, both real (ε′) and imaginary (ε″) parts of complex permittivity increase from ~ 3.25 and ~ 0.2 to ~ 7.5 and ~ 2.8, respectively. Microwave reflection loss of porous glass was calculated based on the permittivity in the range of 8.2–12.4 GHz(X-band). Reflection loss of foam glass decreases as graphite additive and the sample with 2.0 wt% graphite additive achieve reflection loss less than ? 10 dB in whole X-band with thickness ranging from 2.3 to 3.5 mm. Linear relation between reduction of reflectivity and increase of graphite content is achieved. The results show that changing foaming agent additive is an efficient way to design dielectric and microwave absorption properties of foam glass. Foam glass with 1.0 wt% graphite additive may find application in photocatalytic degradation of many environmental pollutants due to its considerable zinc oxide whiskers.     

Stress relaxation behavior of co-continuous PS/PMMA blends after step shear strain

Stress relaxation probing on the immiscible blends is an attractive route to reveal the time-dependent morphology–viscoelasticity correlations under/after flow. However, a comprehensive understanding on the stress relaxation of co-continuous blends, especially after subjected to a shear strain, is still lacking. In this work, the stress relaxation behavior of co-continuous polystyrene/poly(methyl methacrylate) (50/50) blends with different annealing times, strain levels, and temperatures was examined under step shear strain and was correlated with the development of their morphologies. It was found that co-continuous blends display a fast relaxation process which corresponded to the relaxation of bulk polymer and a second slower relaxation process due to the recovery of co-continuous morphology. The stress relaxation rates of co-continuous blends tend to decrease due to the coarsening of instable co-continuous structure during annealing. Furthermore, the stress relaxation of the co-continuous blends is strongly affected by the change of viscosity and interfacial tension caused by the temperature. The contribution of morphological coarsening, viscosity, and interfacial tension variation on the stress relaxation behavior of co-continuous blends was discussed based on the Lee–Park model and time–temperature superposition principle, respectively.     

Effect of synthesis route on the morphologies of silver nanostructures by galvanic displacement reaction

The present study is concerned with the preparation of Ag nanostructures by reduction of AgNO₃ with zinc foil by galvanic displacement reaction. The results confirm that the synthesis route has a direct influence on the morphologies of Ag nanostructures. In addition, the effect of synthesis conditions, including the concentration of AgNO₃ aqueous solutions and reaction time, are investigated. X-ray diffraction (XRD), filed emission scanning electron microscope (SEM) and UV-vis spectra are used to characterize the obtained products. A reasonable formation process of Ag nanostructures is proposed based on the characterization results.     

大功率AlGaInP红光LED散热基板热分析

采用有限体积数值模拟、瞬态热阻测试方法以及热沉温度一峰值波长变化的关系,对三种散热基板上大功率AIGaInP红光发光二极管(LED)进行热特性分析.三种LED采用相同型号、规格,散热基板,区别在于散热通道以及材料.测量样品的瞬态温度响应曲线,基于结构函数理论模型对温度响应曲线进行数学处理,得出包含热阻与热容的结构函数,区分出样品内部热流通道上各个区域的热阻与热容,进而发现散热瓶颈区域.测试样品在不同热沉温度下的电致发光光谱,通过热沉温度一峰值波长系数为区别样品散热性能提供定性判断依据.通过模拟与测试结果比较,为优化陶瓷基板内部散热结构,设计最佳的散热模型提供重要参考依据.     

High-Level Expression,Purification, and In Vitro Refolding of Soluble Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a new member of the TNF superfamily. In this paper, we report the expression, purification, and preparation of a recombinant form of the extracelluar domain of the TRAIL (sTRAIL) without posttranslational modifications, which may selectively induce apoptosis of tumor cells in vitro. To obtain recombinant nonfusion sTRAIL protein, the encoding region for sTRAIL was cloned between KpnI and BamHI in pET32a. The Trx (thioredoxin)/sTRAIL fusion proteins were expressed in the form of inclusion bodies in Escherichia coli host strain BL21 (DE3). The expression level was more than 35% of total cell lysate. Inclusion bodies were disrupted, washed, and isolated at pH 9.0, and were completely dissolved in a buffer containing 2 M urea at pH 9.0. After nickel ion metal affinity chromatography, gel filtration chromatography, and renaturation, the refolded fusion proteins with a purity of >98% were obtained. Trx/sTRAIL L proteins were digested by enterokinase to both Trx and sTRAIL fragments, which then were separated by cation exchange chromatography. Cell proliferation experiments proved that the rsTRAIL (98% purity) retains its cancer-selective apoptosis-inducing properties. This result suggested that the recombinant sTRAIL may have cancer therapeutic applications.     

Application of gradient descent method to the sedimentary grain-size distribution fitting

Existence of a least squares solution for a sum of several weighted normal functions is proved. The gradient descent (GD) method is used to fit the measured data (i.e. the laser grain-size distribution of the sediments) with a sum of three weighted lognormal functions. The numerical results indicate that the GD method is not only easy to operate but also could effectively optimize the parameters of the fitting function with the error decreasing steadily. Meanwhile the overall fitting results are satisfactory. As a new way of data fitting, the GD method could also be used to solve other optimization problems.     

Solutions for a generalized fractional anomalous diffusion equation

In this paper, we investigate the solutions for a generalized fractional diffusion equation that extends some known diffusion equations by taking a spatial time-dependent diffusion coefficient and an external force into account, which subjects to the natural boundaries and the generic initial condition. We obtain explicit analytical expressions for the probability distribution and study the relation between our solutions and those obtained within the maximum entropy principle by using the Tsallis entropy.