Photocatalytic oxidation of low concentration 2,4-D solution with new TiO2 fiber catalyst in a continuous flow reactor.

Environmental pollution by low concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) is a concern these days due to ever increasingly stringent regulations. Photocatalysis with immobilized TiO2 fiber is a promising oxidation method. Laboratory experiments on photocatalytic degradation of 0.045 mmol l(-1) 2,4-D with the world's first high-strength TiO2 fiber catalyst were carried out in a continuous flow reactor in which the degradations were, in general, similar to those with high 2,4-D concentrations investigated elsewhere. Degradation and mineralization of 2,4-D were significantly enhanced with no initial pH adjustments. The rate constants for total organic carbon (TOC) without pH adjustment were about two-fold bigger than the pH adjustment cases. CO2 gas measurement and carbon mass-balance were carried out for the first time, where about 34% organic carbon converted into CO2 gas during four-hour oxidation. 2,4-Dichlorophenol (2,4-DCP), phenol, benzyl alcohol and two unknowns (RT = 2.65 and 3.78 min.) were detected as aromatic intermediates while Phenol was the new aromatic in HPLC analysis. Dechlorination efficiencies were high (> 70%) in all the cases, and more than 90% efficiencies were observed in chloride mass balance. Bigger flow rates and solution temperature fixed at 20 degrees C without pH adjustment greatly enhanced 2,4-D mineralization. These results can be an important basis in applying the treatment method for dioxin-contaminated water and wastewater.     

弹性波衍射CT

本文直接从等价于弹性动力学Ｎａｖｉｅｒ方程的耦合齐次与非齐次矢量波动方程组出发，围绕弹性波衍射ＣＴ展开了理论研究，尤其是其非齐次方程含有震源项，同时适合Ｐ波和Ｓ波，考虑爆炸震源，引进塑性半径，运用张量运算，推导了Ｂｏｒｎ近似下散射波谱与目标函关系，得到二种数据采集方式下的层析成像ＦＢＰ公式，可同时适用于Ｐ波和Ｓ波，尽管与以往不涉及震源项的结果相似，但本结果更符合地震勘探情况。     

过程控制仪表可靠性试验综述

综述了对过程控制仪表进行试验室可靠性试验和现场可靠性试验的方法和步骤，介绍了过程控制仪表可靠性寿命试验与环境试验的关系，并提出了协调、综合两种试验设想。     

Improved visible-light responsive photocatalytic activity of N and Si co-doped titanias

Thermal reaction of titanium tetraisopropoxide and tetraethyl orthosilicate in 1,4-butanediol afforded nanocrystalline silica-modified titanias having large surface area and superior thermal stability. In this study, the thus-obtained silica-modified titanias were treated in an NH₃ flow at high temperatures, and their physical and photocatalytic properties were investigated. Compared with NH₃-treated TiO₂ without silica modification, the NH₃-treated silica-modified titanias showed a stronger absorption in the visible region (400–500 nm) and had a larger peak at 396 eV in the N 1s XPS spectrum. These results indicate that a larger amount of nitrogen was stably doped in the silica-modified titania. The obtained products exhibited a high photocatalytic activity for degradation of Rhodamine B and decomposition of acetaldehyde under visible light irradiation. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A cathode readout gas sampling calorimeter with conductive plastic tubes

We constructed and tested a prototype gas sampling electromagnetic calorimeter of the Pb-proportional tube sandwich type. The calorimeter uses conductive plastic tubes and cathode pad readout with a tower structure which resulted in reasonable energy and spatial resolutions for electrons in the momentum range 0.5–4.0 GeV/c; $\text{σ}{}_{\mathrm{E}}\text{E =}\text{21\%}\text{(E(}\text{GeV}\text{)}\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, σ}{}_{\mathrm{x}}\text{= 6}\text{mm}\text{(at 3 GeV}$/c). This paper describes the test and the performance studied under various conditions.     

Removal of endocrine disrupting chemicals (EDCs) using low pressure reverse osmosis membrane (LPROM).

Endocrine disrupting chemicals (EDCs) are the focus of current environmental issues, as they can cause adverse health effects to animals and human, subsequent to endocrine function. The objective of this study was to remove a specific compound of EDCs (i.e. pentachlorophenol, C(6)OCL(5)Na, molecular weight of 288 g/mol) using low pressure reverse osmosis membrane (LPROM). A cross flow module of LPROM was used to observe the effects of operating parameters, i.e. pH, operating pressure and temperature. The design of the experiment was based on MINITAB(TM) software, and the analysis of results was conducted by factorial analysis. It was found that the rejection of pentachlorophenol was higher than 80% at a recovery rate of 60 to 70%. The rejection was subjected to increase with the increase of pH. The flux was observed to be increased with the increase of operating pressure and temperature. This study also investigated the interaction effects between operating parameters involved.     

On the elemental effect of AlCoCrCuFeNi high-entropy alloy system

The AlCoCrCuFeNi high-entropy alloy system was synthesized using a well-developed arc melting and casting method. Their elemental effect on microstructures and hardness was investigated with X-ray diffraction, scanning electron microscopy and Vickers hardness testing. The alloys exhibit quite simple FCC and BCC solid solution phases. Co, Cu and Ni elements enhance the formation of the FCC phase while Al and Cr enhance that of the BCC phase in the alloy system. BCC phases form a spinodal structure during cooling. Copper tends to segregate at the interdendrite region and forms a Cu-rich FCC phase. Low copper content renders the interdendrite as a thin film and the as-cast structure like recrystallized grain structure. The formation of BCC phases significantly increases the hardness level of the alloy system. The strengthening mechanism is discussed.     

框架结构焦仓的定向倒塌爆破

介绍了框架结构焦仓定向爆破拆除的设计与施工，着重介绍了爆破参烽的选取及安全防护措施。达到预期的爆破效果。     

Viscous and Aeroelastic Effects on Wind Turbine Blades. The VISCEL project. Part I: 3D Navier–Stokes Rotor simulations

Aerodynamic modelling of HAWT rotors by means of “engineering methods” has reached a saddle point, where no further development can be expected without a breakthrough in understanding the physics of unsteady, rotating three‐dimensional flows. However, such a breakthrough becomes ever more necessary, as the size of the wind turbines increases. With the experimental work in that direction being mostly limited to observing the phenomena and interpreting the associated mechanisms, and its increased cost, alternatives are being sought. The use of CFD techniques and state‐of‐the‐art Navier–Stokes solvers is considered a very serious contender, a belief shared by the members of the present consortium, which has worked on the VISCEL JOR3‐CT98‐0208 Joule III project. This project's goal was to determine the aerodynamic characteristics as well as the aeroelastic behaviour of wind turbine blades across their broad range of operational conditions, from attached to highly separated flow regimes. The work programme included specific tasks for the validation and assessment of existing 3D solvers, for the parametric study of 3D flow around realistic blades and for the investigation of aeroelastic stability, at the blade section level. Copyright © 2003 John Wiley & Sons, Ltd.