High efficient removal of HCN over porous CuO/CeO2 micro-nano spheres at lower temperature range

The porous CeO2 flowerlike micro-nano spheres based materials were prepared to remove HCN effectively at lower temperature range.The CeO2 and a serious of porous flowerlike ceria based materials loaded with metal species including Cu,Ag,Ni,Co and Fe were synthesized by hydrothermal method and precipitation method respectively.The physicochemical properties were probed by means of XRD,H2-TPR,BET,SEM and XPS.The removal ability for 130 mg·m﹣3 HCN over CuO/CeO2 showed the highest activity,the breakthrough time of which was more than 70 min at the condition of 30℃,120,000 h-1 and b 5%(volume)H2O,owe to a higher relative atomic ratio of oxygen vacancies and Oβ,the stronger interaction between metal particle and support,the optimum redox properties.The reaction mechanism was speculated by detecting the reaction products selectivity at different reaction temperature.It was shown that the reaction system for removal of HCN over CuO/CeO2 catalytic material involved chemisorption,catalytic hydrolysis,catalytic oxidation as well as NH3-SCR reactions.

On the low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing

The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain amplitudes.We showed that NIA improved the low cycle fatigue life(more than 7000 cycles)by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties(570 MPa for tensile strength)and conductivity(nearly 39%IACS)to conventional isothermal ageing,simultaneously.Experimental observation combined with molecular dynamic simula-tion revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resis-tance.A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA,responsible for the dramatic displacement steps on the surface and resultant poor fatigue performance.As the NIA further proceeded,moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density ef-fectively impeded the dislocation movement and weaken the slip localisation to a great extent,improving the fatigue performance within a few hours.

Time-domain terahertz optoacoustics: manipulable water sensing and dampening

Radiation at terahertz frequencies can be used to analyze the structural dynamics of water and biomolecules,but applying the technique to aqueous solutions and tissues remains challenging since terahertz radiation is strongly absorbed by water.While this absorption enables certain analyses,such as the structure of water and its interactions with biological solutes,it limits the thickness of samples that can be analyzed,and it drowns out weaker signals from biomolecules of interest.We present a method for analyzing water-rich samples via time-domain terahertz optoacoustics over a 104-fold thickness ranging from microns to centimeters.We demonstrate that adjusting the temperature to alter the terahertz optoacoustic(THz-OA)signal of water improves the sensitivity with which it can be analyzed and,conversely,can reduce or even“silence”its signal.Temperature-manipulated THz-OA signals of aqueous solutions allow detection of solutes such as ions with an order of magnitude greater sensitivity than terahertz time-domain spectroscopy,and potentially provide more characteristic parameters related to both terahertz absorption and ultrasonic propagation.Terahertz optoacoustics may be a powerful tool for spectroscopy and potential imaging of aqueous solutions and tissues to explore molecular interactions and biochemical processes.