structure modification
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Author(s):  
Sahadeb Ghosh ◽  
Mangala Nand ◽  
Rajiv Kamparath ◽  
Mukul Gupta ◽  
Devdatta M Phase ◽  
...  

Abstract Oriented thin films of β-(Ga1-xFex)2O3 have been deposited by RF magnetron sputtering on c-Al2O3 and GaN substrates. The itinerant character of Fe 3d states forming the top of the valence band (VB) of Fe substituted of β-Ga2O3 thin films has been determined from resonant photoelectron spectroscopy (RPES). Further, admixture of itinerant and localized character of these Fe 3d sates is obtained for larger binding energies i.e deeper of VB. The bottom of the conduction band (CB) for β-(Ga1-xFex)2O3 is also found to be strongly hybridized states involving Fe 3d and O 2p states as compared to that of Ga 4s in pristine β-Ga2O3. This suggests that β-Ga2O3 transforms from band like system to a charge transfer system with Fe substitution. Furthermore, the bandgap red shits with Fe composition, which has been found to be primarily related to the shift of the CB edge.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1946
Author(s):  
Anastasiya D. Shlyaptseva ◽  
Igor A. Petrov ◽  
Alexandr P. Ryakhovsky ◽  
Elena V. Medvedeva ◽  
Victor V. Tcherdyntsev

The possibility of using complex structure modification for aluminium casting alloys’ mechanical properties improvement was studied. The fluxes widely used in the industry are mainly intended for the modification of a single structural component of Al–Si alloys, which does not allow unifying of the modification process in a production environment. Thus, a new modifying flux that has a complex effect on the structure of Al–Si alloys has been developed. It consists of the following components: TiO2, containing a primary α-Al grain size modifier; BaF2 containing a eutectic silicon modifier; KF used to transform titanium and barium into the melt. The effect of the complex titanium dioxide-based modifier on the macro-, microstructure and the mechanical properties of industrial aluminium–silicon casting alloys containing 5%, 6%, 9%, 11% and 17% Si by weight was studied. It was found that the tensile strength (σB) of Al–Si alloys exceeds the similar characteristics for the alloys modified using the standard sodium-containing flux to 32%, and the relative elongation (δ) increases to 54%. The alloys’ mechanical properties improvement was shown to be the result of the flux component’s complex effect on the macro- and microstructure. The effect includes the simultaneous reduction in secondary dendritic arm spacing due to titanium, the refinement and decreasing size of silicon particles in the eutectic with barium and potassium, and the modifying of the primary silicon. The reliability of the studies was confirmed using up-to-date test systems, a significant amount of experimental data and the repeatability of the results for a large number of samples in the identical initial state.


2021 ◽  
Vol 117 (3) ◽  
pp. 1
Author(s):  
Zahra SHEKARI ◽  
Zahra TAHMASEBI ◽  
Homayoun KANOUNI ◽  
Ali ashraf MEHRABI

<p class="042abstractstekst">Root structure modification can improve important agronomic traits including yield, drought tolerance and nutrient deficiency resistance. The aim of the present study was to investigate the diversity of root traits and to find simple sequence repeat (SSR) markers linked to root traits in chickpea (<em>Cicer arietinum </em>L.). This research was performed using 39 diverse accessions of chickpea. The results showed that there is significant variation in root traits among chickpea genotypes. A total of 26 alleles were detected 26 polymorphic bands were produced by 10 SSR markers in the eight linkage groups (LG). The results indicated that there is substantial variability present in chickpea<strong> </strong>germplasm for root traits.<strong> </strong>By analyzing the population structure, four subpopulations were identified.<strong> </strong>PsAS2, AF016458, 16549 and 19075 SSR markers on LG1, LG3, LG2 and LG1 linkage group respectively were<strong> </strong>associated with root traits<strong>.</strong> The research findings provide valuable information for improving root traits for chickpea breeders.</p>


2021 ◽  
Vol 117 (3) ◽  
pp. 1
Author(s):  
Zahra SHEKARI ◽  
Zahra TAHMASEBI ◽  
Homayoun KANOUNI ◽  
Ali ashraf MEHRABI

<p class="042abstractstekst">Root structure modification can improve important agronomic traits including yield, drought tolerance and nutrient deficiency resistance. The aim of the present study was to investigate the diversity of root traits and to find simple sequence repeat (SSR) markers linked to root traits in chickpea (<em>Cicer arietinum </em>L.). This research was performed using 39 diverse accessions of chickpea. The results showed that there is significant variation in root traits among chickpea genotypes. A total of 26 alleles were detected 26 polymorphic bands were produced by 10 SSR markers in the eight linkage groups (LG). The results indicated that there is substantial variability present in chickpea<strong> </strong>germplasm for root traits.<strong> </strong>By analyzing the population structure, four subpopulations were identified.<strong> </strong>PsAS2, AF016458, 16549 and 19075 SSR markers on LG1, LG3, LG2 and LG1 linkage group respectively were<strong> </strong>associated with root traits<strong>.</strong> The research findings provide valuable information for improving root traits for chickpea breeders.</p>


2021 ◽  
Vol 22 (22) ◽  
pp. 12185
Author(s):  
Guifei Gu ◽  
Sen Yang ◽  
Xianhui Yin ◽  
Youhua Long ◽  
Yue Ma ◽  
...  

Bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) has led to considerable losses in all major kiwifruit-growing areas. There are no commercial products in the market to effectively control this disease. Therefore, the defense resistance of host plants is a prospective option. In our previous study, sulfur could improve the resistance of kiwifruit to Psa infection. However, the mechanisms of inducing resistance remain largely unclear. In this study, disease severity and protection efficiency were tested after applying sulfur, with different concentrations in the field. The results indicated that sulfur could reduce the disease index by 30.26 and 31.6 and recorded high protection efficiency of 76.67% and 77.00% after one and two years, respectively, when the concentration of induction treatments was 2.0 kg/m3. Ultrastructural changes in kiwifruit stems after induction were demonstrated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO), and the accumulation of lignin were determined by biochemical analyses. Our results showed that the morphological characteristics of trichomes and lenticels of kiwifruit stem were in the best defensive state respectively when the sulfur concentration was 3.0 kg/m3 and 1.5 kg/m3. Meanwhile, in the range of 0.5 to 2.0 kg/m3, the sulfur could promote the chloroplast and mitochondria of kiwifruit stems infected with Psa to gradually return to health status, increasing the thickness of the cell wall. In addition, sulfur increased the activities of PAL, POD and PPO, and promoted the accumulation of lignin in kiwifruit stems. Moreover, the sulfur protection efficiency was positively correlated with PPO activity (p < 0.05) and lignin content (p < 0.01), which revealed that the synergistic effect of protective enzyme activity and the phenolic metabolism pathway was the physiological effect of sulfur-induced kiwifruit resistance to Psa. This evidence highlights the importance of lignin content in kiwifruit stems as a defense mechanism in sulfur-induced resistance. These results suggest that sulfur enhances kiwifruit canker resistance via an increase in phenolic components and morphology structure modification in the kiwifruit stems. Therefore, this study could provide insights into sulfur to control kiwifruit canker caused by Psa.


2021 ◽  
Vol 2076 (1) ◽  
pp. 012036
Author(s):  
Wenwen Liu ◽  
Kaiqin Xu ◽  
Renfu Peng ◽  
Fang Xie ◽  
Huan Chen

Abstract Carbon nitride (C3N4) is a promising photocatalytic material to degrade various pollutants. However, the degradation activity is restricted by the limited light absorption and fast recombination of photoinduced carriers. Herein, a structure modification strategy by introducing a functional reagent during the polymerization process was adopted. The structure, composition and morphology of prepared materials were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. Benefiting from the implantation of oxygen and methyl groups in triazine unit of C3N4, enhanced light absorption and effective carrier separation are achieved. As a result, the modified C3N4 exhibits a significant enhanced degradation activity and the optimal rate constant of modified C3N4 for Acid Red 9 degradation is 5.83 times that of pristine C3N4. The work demonstrates the effect of structure modification in C3N4 for enhancing degradation activity.


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