Use of multiple isotopes to evaluate nitrate dynamics in groundwater under the barrier effect of underground cutoff walls

Author(s):  
Pingping Kang ◽  
Shaopeng Li ◽  
Fuqiang Wang ◽  
Heng Zhao ◽  
Subing Lv
2014 ◽  
Vol 1052 ◽  
pp. 163-168 ◽  
Author(s):  
Xiao Na Li ◽  
Lu Jie Jin ◽  
Li Rong Zhao ◽  
Chuang Dong

Thermal stability, adhesion and electronic resistivity of the Cu alloy films with diffusion barrier elements (large atom Sn and small atom C) have been studied. Ternary Cu (0.6 at.% Sn, 2 at.% C) films were prepared by magnetron co-sputtering in this work. The microstructure and resistivity analysis on the films showed that the Cu (0.6 at.% Sn, 2 at.% C) film had better adhesion with the substrate and lower resistivity (2.8 μΩ·cm, after annealing at 600 °C for 1 h). Therefore, the doping of carbon atoms makes less effect to the resistivity by decreasing the amount of the doped large atoms, which results in the decreasing of the whole resistivity of the barrierless structure. After annealing, the doped elements in the film diffused to the interface to form self-passivated amorphous layer, which could further hinder the diffusion between Cu and Si. So thus ternary Cu (0.6 at.% Sn, 2 at.% C) film had better diffusion barrier effect. Co-doping of large atoms and small atoms in the Cu film is a promising way to improve the barrierless structure.


2020 ◽  
pp. 148849
Author(s):  
Yu Shi ◽  
Sheng Yuan ◽  
Benoit Ter-Ovanessian ◽  
Kurt Hermange ◽  
Ying Huo ◽  
...  

2015 ◽  
Vol 659 ◽  
pp. 394-398 ◽  
Author(s):  
Nutthaphon Liawthanyarat ◽  
Sarawut Rimdusit

Polybenzoxazine nanocomposites filled with three different sizes of silica nanoparticles are investigated for their mechanical and thermal properties. In this research, silica nanoparticles with primary particle sizes of 7, 14 and 40 nm were incorporated in polybenzoxazine matrix at a fixed content of 3% by weight. From the experimental results, the storage modulus of the polybenzoxazine nanocomposite was found to systematically increase with decreasing the particle sizes of nanosilica suggesting better reinforcement of the smaller particles. Glass transition temperature was found to slightly increase with the addition of the silica nanoparticles. The uniformity of the composite samples were also evaluated by thermogravimetric analysis to show good dispersion of the silica nanoparticles in the composite samples as a result of high processability of the benzoxazine resin used i.e. low A-stage viscosity with good wetting behaviors. Degradation temperature at 5% weight loss (Td,5) of polybenzoxazine nanocomposites filled with different particle sizes of silica nanoparticles was found to increase from the value of 325 °C of the neat polybenzoxazine to the maximum value of about 340 °C with an addition of the nanosilica of the smallest particle size used. Finally, the smaller nanosilica particle size was also found to show more pronounced effect on Td,5enhancement of the composite samples as a result of greater barrier effect from larger surface area of the smaller particles.


Author(s):  
Sandeep Saxena ◽  
Levent Akduman ◽  
Carsten H. Meyer

AbstractAdvances in spectral-domain optical coherence tomography (SD-OCT) technology have enhanced the understanding of external limiting membrane (ELM) and ellipsoid zone (EZ) in diabetic macular edema. An increase in VEGF has been demonstrated to be associated with sequential ELM and EZ disruption on SD-OCT. An intact ELM is a prerequisite for an intact EZ in DME. Anti-VEGF therapy leads to restoration of barrier effect of ELM. The ELM restores first followed by EZ restoration.


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