Search

On the basis of experimental research about PVA fiber concrete, combined with the technology measures such as expansive belt, construction quality monitoring, the jointless design and construction is successfully carried out for an industry tank. The water storage test results showed that impervious performances can meet the requirements of specification and achieved desired effects.

For the purpose of developing an effective Fe2O3-doped nickel-based catalysts to be used in biomass gasification, Fe2O3nanoparticles were prepared by homogeneous precipitation method involving an aqueous solution of Fe (NO3)3·9H2O and urea as precipitator. Different approaches, such as XRD and SEM, were used to characterize the products. Meanwhile, the effects of various technical parameters in preparation process on the yield of products were investigated, and optimal conditions for preparing Fe2O3nanoparticles were found as follows: the molar ratio of urea to Fe (NO3)3·9H2O for 5:1, temperature of precipitation reaction for 125°C, concentration of iron salt for 0.20mol/L. The Fe2O3nanoparticles prepared under the optimal conditions were spherical in shape and well dispersed; they had high purity and a fine crystal phase of cubic syngony with a mean particle size of about 28nm.

nanoAl2O3 has been synthesized by homogeneous precipitation method using dodecyl trimethyl ammonium bromide (DTAB) as surfactant. The as-prepared powder was characterized by FT-IR, XRD, TEM and SEM. The results indicate the surfactant existence in the precursors but disappeared in the products. This is mainly due to the combination of precursor and surfactant, which results in particles of nanosize. The nucleation and growth rate during the precipitation has also been controlled by the addition of surfactant. During the calcination process, the surfactant has decomposed and volatilized into air. The XRD characterization shows the calcined powders were γ-Al2O3 particles with mean size of 27 nm, which was in accordance with TEM characterization. The morphology of the prepared alumina particles has also been investigated by SEM and showed that the powder has a spherical morphology with a uniform particle size.

NiO nanoparticles were successfully prepared by decomposing the predecessor bis(glycinato)nickel(II)dihydrate in the presence of oleylamine and triphenylphosphine (TPP), and different approaches including Fourier transforms infrared spectrometry(FT-IR), X-ray diffraction(XRD) and transmission electron microscopy (TEM) were used to characterize the NiO nanoparticles. Meanwhile, the effects of TPP concentration and reaction time on the size and yield of NiO nanoparticles derived from precursors were thoroughly investigated in this paper. The analysis results indicated that the prepared NiO nanoparticles were found spherical in shape and demonstrated weak agglomeration. They had generally high purity and a fine crystal phase of cubic syngony. Furthermore, the effects of the TPP concentration and reaction time on the size and yield of NiO nanoparticles are very crucial, higher concentration of TPP would results in reduction of both the mean size and yield of NiO particles. However both yields and particles size of NiO nanoparticles continuously increased as increasing reaction time, after more than 60 minutes, the size and yield of NiO nanoparticles kept hardly change.

For the purpose of developing a novel and effective nano-CeO2catalyst used in biomass gasification for tar removal, nanocrystalline CeO2particles were successfully prepared by the homogeneous precipitation method, and different approaches including TG, FT-IR, XRD and SEM were used to characterize the CeO2nano-particles and precursors in this study. The analysis results indicated that the synthesized precursor was hydrated cerium basic carbonates and its formula was identified as Ce2O(CO3)2•nH2O, and it can completely transform into nanocrystalline CeO2particles below 400 °C under the air atmosphere. The prepared CeO2nano-particles were found spherical in shape and well dispersed; they had high purity and a fine crystal phase of cubic syngony structure with a mean size of 13 nm.

We utilized the strategy of ‘borrowing SERS activity’, by chemically coating several atomic layers of a Pt-group metal on highly SERS-active Au nanoparticles, to obtain the first SERS (also Raman) spectra of surface water on Pt and Pd metals, and propose conceptual models for water adsorbed on Pt and Pd metal surfaces.