We put forward effective methods of increasing the tensile strain of cementitious composites with 2% PVA fiber and high fly ash content. The test results show that curing condition has a significantly effect on the te...We put forward effective methods of increasing the tensile strain of cementitious composites with 2% PVA fiber and high fly ash content. The test results show that curing condition has a significantly effect on the tensile performance. It is approved that the specimens incorporated appropriate volume fraction rubber powder and lightweight aggregate greatly increase the tensile strain of composites at medium-term age, but indefinitely at long-term age. To a certain extent, EVA can limitedly enhance the tensile performance of comentitious composites owing to the formation of polymer membrane and the hindered hydration of cement.展开更多
A simple and novel method was developed to determine methylene blue（MB） by resonance light scattering（RLS） using silica nanoparticles（SiO2NPs） as the probe.It was found that MB could enhance the RLS intensity of...A simple and novel method was developed to determine methylene blue（MB） by resonance light scattering（RLS） using silica nanoparticles（SiO2NPs） as the probe.It was found that MB could enhance the RLS intensity of SiO2NPs.Moreover,the increase in RLS intensity was linear with the concentration of MB over the range of 0.01-3.0 μg mL^-1.The limit of detection（LOD） was as low as 4.36 ng mL^-1（3σ） and the relative standard deviation（RSD） was 2.4%（n=6）.Under the optimum experimental conditions,this proposed method was successfully applied for the determination of MB in aquaculture samples with recoveries between 96.3% and 107%.Possible mechanisms for the RLS enhancement of SiO2NPs in the presence of MB were also discussed.展开更多
基金Funded by National Basic Research Program of China (973 Program) (No. 2009CB623200)Hong Kong Research Grant Council under CERG 616405
文摘We put forward effective methods of increasing the tensile strain of cementitious composites with 2% PVA fiber and high fly ash content. The test results show that curing condition has a significantly effect on the tensile performance. It is approved that the specimens incorporated appropriate volume fraction rubber powder and lightweight aggregate greatly increase the tensile strain of composites at medium-term age, but indefinitely at long-term age. To a certain extent, EVA can limitedly enhance the tensile performance of comentitious composites owing to the formation of polymer membrane and the hindered hydration of cement.
文摘A simple and novel method was developed to determine methylene blue（MB） by resonance light scattering（RLS） using silica nanoparticles（SiO2NPs） as the probe.It was found that MB could enhance the RLS intensity of SiO2NPs.Moreover,the increase in RLS intensity was linear with the concentration of MB over the range of 0.01-3.0 μg mL^-1.The limit of detection（LOD） was as low as 4.36 ng mL^-1（3σ） and the relative standard deviation（RSD） was 2.4%（n=6）.Under the optimum experimental conditions,this proposed method was successfully applied for the determination of MB in aquaculture samples with recoveries between 96.3% and 107%.Possible mechanisms for the RLS enhancement of SiO2NPs in the presence of MB were also discussed.
