Recent developments in visible-light photocatalytic degradation of antibiotics

With the significant discharge of antibiotic wastewater into the aquatic and terrestrial ecosystems, antibiotic pollution has become a serious problem and presents a hazardous risk to the environment. To address such issues, various investigations on the removal of antibiotics have been undertaken. Photocatalysis has received tremendous attention owing to its great potential in removing antibiotics from aqueous solutions via a green, economic, and effective process. However, such a technology employing traditional photocatalysts suffers from major drawbacks such as light absorption being restricted to the UV spectrum only and fast charge recombination. To overcome these issues, considerable effort has been directed towards the development of advanced visible light-driven photocatalysts. This mini review summarises recent research progress in the state-of-the-art design and fabrication of photocatalysts with visible-light response for photocatalytic degradation of antibiotic wastewater. Such design strategies involve the doping of metal and non-metal into ultraviolet light-driven photocatalysts, development of new semiconductor photocatalysts, construction of heterojunction photocatalysts, and fabrication of surface plasmon resonance-enhanced photocatalytic systems. Additionally, some perspectives on the challenges and future developments in the area of photocatalytic degradation of antibiotics are provided.

浅析高层建筑外脚手架的选择与布设

板式体型建筑物一般可以根据建筑物的高度将外挂式脚手架和扣件式钢管脚手架 ,挑脚手架等其它脚手架形式组合使用。

MMCs平台惯导仪表动态可靠性分析

金属基复合材料 ( MMCs)有适合于惯导仪表的多项优异特性且性能价格比较好 ,三种主要制备技术在国内均已成熟 ,该材料应用的主要技术问题已基本解决。根据平台惯导系统的特点对铝基 MMCs进行了讨论并针对某小型平台作了力学及可靠性分析。预计该材料将在未来两年后可批量应用于惯导仪表中。

Monolithic Integration of InGaP/AlGaAs/InGaAs Enhancement/Depletion-Mode PHEMTs

The monolithic integration of enhancement- and depletion-mode （E/D-mode） InGaP/AIGaAs/InGaAs pseudomorphic high electron mobility transistors （PHEMTs） with a 1.0μm gate length is presented. Epilayers are grown on SI GaAs substrates using MBE. For this structure, a mobility of 5410cm^2/（V · s） and a sheet density of 1.34 × 10^12 cm^-2 are achieved at room temperature. During the gate fabrication of E/D-mode PHEMTs,a novel twostep technology is applied. The devices with a gate dimension of 1μm × 100μm exhibit good DC and RF performances. Threshold voltages of 0. 2 and -0. 4V,maximum drain current densities of 300 and 340mA/mm,and extrinsic transconductances of 350 and 300mS/mm for E- and D-mode PHEMTs are obtained, respectively. The reverse gatedrain breakdown voltage is -14V for both E- and D-mode. Current-gain cutoff frequencies of 10. 3 and 12.4GHz and power-gain cutoff frequencies of 12.8 and 14.7GHz for E- and D-mode are reported, respectively.

Dry sliding wear behavior of stir cast AA6061-T6/AlN_p composite

The dry sliding wear behavior of AA6061 matrix composite reinforced with aluminium nitride particles（AlN） produced by stir casting process was investigated. A regression model was developed to predict the wear rate of the prepared composite. A four-factor, five-level central composite rotatable design matrix was used to minimize the number of experimental runs. The factors considered in this study were sliding velocity, sliding distance, normal load and mass fraction of AlN reinforcement in the matrix. The developed regression model was validated by statistical software SYSTAT 12 and statistical tools such as analysis of variance（ANOVA） and student＇s t test. It was found that the developed regression model could be effectively used to predict the wear rate at 95% confidence level. The influence of these factors on wear rate of AA6061/AlNp composite was analyzed using the developed regression model and predicted trends were discussed with the aid of worn surface morphologies. The regression model indicated that the wear rate of cast AA6061/AlNp composite decreased with an increase in the mass fraction of AlN and increased with an increase of the sliding velocity, sliding distance and normal load acting on the composite specimen.

Acute hemodynamic effects of enhanced external counterpulsation

Introduction In the United States, there are about 17.6 million patients suffer from symptomatic coronary artery disease （CAD）, affecting 7.9% of adults ≥ 20 years of age.1 An estimated 10.2 million patients have angina, and 500,000 patients will develop new angina pectoris each year. 1 A subset of angina patients are categorized as refractory when symptoms continue despite optimal medical therapy and revascularization.Routine daily activities become impossible without experiencing chest pain in this patient population.2

Construction,Stable Expression of Survivin shRNA Vector

Objective： To construct sarvivin shRNA expression vector carting enhanced green fluorescent protein gene, transfect it into GBC-SDH cells via electroporation, and get GBC-SD cells which are stable expressing survivin shRNA. Methods： The siRNA sequence targeting survivin mRNA was synthesized and cloned into pEGFP-H1. The constructed plasmid and pEGFP-H1 were transfected into GBC-SI） cells respectively via liposome, and the transfecting effect was detected with Flow Cytometry. Then the transfected cells were selected with G418. Results： The recombinant plasmid was successfully constructed, named pEGFP-survivin. The gene transfection efficiencies in pEGFP-H1-transfected group and pEGFP-survivin- transfected group were the 80.29% ± 2.71% and 83.85% ±2.34%（P〉0.05）, which was successful to get the cells that are stable expressing shRNA, named GBC-SD/EGFP and GBC-SD/survivin. Conclusion： Survivin shRNA successfully and got GBC-SD cells which are stable expression vector was constructed expression shRNA.

Gas Turbulence Modulation Model for Gas-Solid Flows in Two-Fluid Approach

Turbulence enhancement by particle wake effect is studied by numerical simulation of gas turbulent flows passing over particle under various particle sizes, inlet gas velocities, gas viscosity, gas density and the distance of particles. By performing dimension analysis and using the form of gas-particle interaction source term for reference, a new semi-empirical turbulence enhancement model by the particle-wake effect is proposed. The turbulence model is then incorporated into second-order moment model for simulating gas-particle flows in a horizontal channel with different wall roughness and a sudden-expansion chamber. The results show that this model is with higher calculating accuracy than another two turbulence models in comparison with the experimental results.

Resonant cavity enhanced photoluminescence of tensile strained Ge/SiGe quantum wells on silicon-on-insulator substrate

The tensile strained Ge/SiGe multiple quantum wells （MQWs） grown on a silicon-on-insulator （SOI） substrate were fabricated successfully by ultra-high chemical vapor deposition. Room temperature direct band photoluminescence from Ge quantum wells on SOI substrate is strongly modulated by Fabry-Perot cavity formed between the surface of Ge and the interface of buried SiO2. The photoluminescence peak intensity at 1.58 μm is enhanced by about 21 times compared with that from the Ge/SiGe quantum wells on Si substrate, and the full width at half maximum （FWHM） is significantly reduced. It is suggested that tensile strained Ge/SiGe multiple quantum wells are one of the promising materials for Si-based microcavity lijzht emitting devices.