Resistive Switching Behavior of Magnesium Zirconia Nickel Nanorods

To effectively improve the uniformity of switching behavior in resistive switching devices, this study developed magnesium zirconia nickel (MZN) nanorods grown on ITO electrodes through hydrothermal method. The field emission scanning electron microscope image shows the NR formation. Al/MZN NR/ITO structure exhibits forming-free and bipolar resistive switching behaviors. MZN NRs have relatively higher ON/OFF ratio and better uniformity compared with MZN thin film. The superior properties of MZN NRs can be attributed to its distinct geometry, which leads to the formation of straight and extensible conducting filaments along the direction of MZN NR. The results suggest the possibility of developing sol–gel NR-based resistive memory devices.

Fabrication of Nanosticks-Like CdS Sensitizer for the Application of Solar Cells

The novelty of this work is to fabricate the Nanosticks (NSs) like CdS sensitizer on the surface of TiO2 electrode by chemical bath deposition (CBD) method with a very high vacuum annealed at 350 °C for 30 min. Whereas, nanocrystalline TiO2 electrodes have been prepared on FTO (SnO2: F) glass by a spin-coating method with high purity (99.99%, Degussa P25) TiO2 powder. The surface of the CdS layer has been covered by NSs like structures which are confirmed by the scanning electron microscope image. The 100 nm of platinum-coated FTO substrate and polysulfide-based electrolyte are used to assemble the Grätzel Solar cell (GSC). The performance of solar cell (SC) based on NSs like CdS has been compared with the nanoparticles (NPs) based CdS sensitized SC, where CdS NPs has synthesized by CBD without any post-annealing. The efficiency of NSs like CdS sensitized SC exhibits 2.44%, which is 2 folds of the efficiency of the CdS NPs sensitized SC. The NSs like CdS sensitized SC shows the highest photocurrent 20.24 mA/cm2 compared to CdS NPs based SC.

Synthesis of Monolithic Potassium Geopolymer Ceramics Assisted by Molten Salt

Potassium geopolymer (KGP) ceramics are synthesized by the molten salt method. Metakaolin changes to a potassium geopolymer through a reaction with potassium silicate at 80 °C/24 h. Potassium geopolymer, with a silicon to aluminum (Si/Al) molar ratio of 2, turns into a leucite ceramic in molten potassium salt (KCl) at 900 °C/6 h. X-Ray Diffraction analysis of the KGP treated by molten KCl salt shows the amorphous phase change to leucite crystal phase. A scanning electron microscope image of sintered KGP proves that the grain size of the leucite crystal decreases with soaking time. Compared with solid state sintering, liquid molten salt sintering KGP can be more easily formed into dense ceramics at lower temperatures.

An application of optimized Otsu multi-threshold segmentation based on fireworks algorithm in cement SEM image

In order to facilitate the study of the structure of cement components, this paper uses image processing technology to achieve multi-threshold segmentation for cement scanning electron microscope image under different conditions and applies an optimized Otsu multi-threshold segmentation based on fireworks algorithm. The method designs fitness function with Otsu multi-threshold segmentation method and searches optimal solution by iteration with the fireworks algorithm. Finally, the search problem of optimization is transformed into a multi-variable solution. The experimental results show that this method can achieve the same result as the classical algorithm and it has better convergence and stability, and the method can be widely used in many fields.

Synthesis of Network Polymers Containing Si-Vinylene Units by Mizoroki-Heck Reaction

Network polymers containing Si-vinylene units have been synthesized by Mizoroki-Heck reaction of cyclic siloxane or cubic silsesquioxane compounds with vinyl groups, as joint molecules, and dibromo aryl compounds, as linker molecules, using a Pd catalyst. The reaction of 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane (TVMCTS) or octavinyloctasilsesquioxane (PVOSS) with o, m, p-dibromobenzene (DBB) or 4,4'-dibromobiphenyl (DBBP) yielded the corresponding network polymers, except TVMCTS-oDBB system. Optical properties of the network polymers were studied by UV-vis and photoluminescence spectroscopy, and absorption and emission derived from s-p conjugation of the Si-vinylene units were detected. Copolymerization of TVMCTS-DBB/bromobenzene yielded CHCl3 soluble fraction due to formation of the network fragments. The network polymers of TVMCTS or PVOSS with 2,7-dibromofluorene (BFl) or 9,9-dihexyl-2,7-dibromofluorene were synthesized by the same procedures. Scanning electron microscope image of TVMCTS-BFl network polymer indicated formation of porous structure. The network polymers have been also synthesized by the reactions of multifunctional aryl bromide, as the joint molecules, with divinyl or dially silane compounds, as the linker molecules. The molecular structure of the multifunctional aryl bromide affected the emission wavelengths of the network polymers. In the case of the 2,2’,7,7’-tetrabromo-9,9’-spirobifluorene-based network polymers, the emission spectra widely ranged from 450 to 500 nm, which were sensitive to molecular structure of the divinyl or dially silane compounds.