•Different coating thickness over the Mg alloy matrix and particles was revealed.•Cr(OH)3 and ZrO2 were main components evidenced by XPS with Cr/Zr at.% ratio of ∼ 0.5.•Coated AZ91D alloy revealed ...5.5x increased corrosion resistance.•Reduced corrosion current density by a factor of 2 on coated alloy.
Trivalent chromium conversion (TCC) coating formation on AZ91D magnesium alloy has been investigated using scanning electron microscopy, energy X-ray dispersive spectroscopy (EDS), X-ray photoelectron spectroscoy (XPS). The coating was formed in a commercial SurTec 650 bath. XPS showed that coatings contained mainly Cr, Zr, O, S and F species, which were assigned to hydrated Cr(III) (Cr(OH)3/CrOOH), ZrO2, Cr2(SO4)3, and CrF3, and lower amounts of Mg2+ and Al3+ species assigned to oxide, hydroxide and fluoride. The Cr/Zr atomic ratio was around 0.5. The coating was formed above both α matrix and β (Mg17Al12) grain boundary regions, and it was significantly thicker above the cathodic β phase. Raman spectroscopy evidenced the presence of Cr(VI) species, formed due to oxidation of Cr(III) by H2O2, particularly in the coating above the cathodic sites. Electrochemical impedance spectroscopy revealed that corrosion protection was provided mainly by the barrier layer at the base of the coating, which resulted in a reduction by about a factor of 2 in the anodic and cathodic current density in potentiodynamic polarization curves.
Rechargeable magnesium (Mg) metal batteries are provided with potential advantages over lithium counterparts with respect to volumetric capacity and natural abundance (equivalent to low cost and ...sustainability). However, Mg metal anodes suffer from surface passivating behavior among numerous conventional Mg electrolytes, leading to irreversible Mg plating/stripping behavior. Herein, a modified Mg metal anode with a bismuth (Bi)-based artificial protective layer has been obtained via a facile solution process (soaking briefly in bismuth trichloride solution). This Bi-based protective layer is mainly composed of ion-conducting Bi metal and corresponding alloy and electronically insulating magnesium chloride. Various electrochemical tests and interface characterizations have proved that the protected Mg electrodes effectively inhibit the harmful parasitic reaction between Mg metal and noncorrosive Mg electrolyte, which further enables suppression of uneven growth during repeated Mg stripping/plating. More importantly, the assembled Mg–Cu2–x S and Mg–O2 full batteries utilizing the as-modified Mg anodes all deliver remarkably improved performance owing to the superior protection properties of a Bi-based artificial layer. These novel findings will inspire lot of efforts to modify the Mg metal anode with targeted surface coatings for high-performance rechargeable Mg batteries.
Soybean is one of the most important oil crops in the world. The domestication of wild soybean has resulted in significant changes in the seed oil content and seed size of cultivated soybeans. To ...better understand the molecular mechanisms of seed formation and oil content accumulation, WDD01514 (E1), ZYD00463 (E2), and two extreme progenies (E23 and E171) derived from RILs were used for weighted gene coexpression network analysis (WGCNA) combined with transcriptome analysis.
In this study, both seed weight and oil content in E1 and E171 were significantly higher than those in E2 and E23, and 20 DAF and 30 DAF may be key stages of soybean seed oil content accumulation and weight increase. Pathways such as "Photosynthesis", "Carbon metabolism", and "Fatty acid metabolism", were involved in oil content accumulation and grain formation between wild and cultivated soybeans at 20 and 30 DAF according to RNA-seq analysis. A total of 121 oil content accumulation and 189 seed formation candidate genes were screened from differentially expressed genes. WGCNA identified six modules related to seed oil content and seed weight, and 76 candidate genes were screened from modules and network. Among them, 16 genes were used for qRT-PCR and tissue specific expression pattern analysis, and their expression-levels in 33-wild and 23-cultivated soybean varieties were subjected to correlation analysis; some key genes were verified as likely to be involved in oil content accumulation and grain formation.
Overall, these results contribute to an understanding of seed lipid metabolism and seed size during seed development, and identify potential functional genes for improving soybean yield and seed oil quantity.
Increasing soybean Glycine max (L.) Merr. yield has become a worldwide scientific problem in the world. Many studies have shown that ubiquitination plays a key role in stress response and yield ...formation. In the UniProtKB database, 2,429 ubiquitin‐related proteins were predicted in soybean, however, <20 were studied. One key way to address this lack of progress in increasing soybean yield will be a deeper understanding of the ubiquitin‐proteasome system (UPS) in soybean. In this review, we summarized the current knowledge about soybean ubiquitin‐related proteins and discussed the method of combining phenotype, mutant library, transgenic system, genomics, and proteomics approaches to facilitate the exploration of the soybean UPS. We also proposed the strategy of applying the UPS in soybean improvement based on related studies in model plants. Our review will be helpful for soybean scientists to learn current research progress of the soybean UPS and further lay a theoretical reference for the molecular improvement of soybean in future research by use of this knowledge.
Core Ideas
Ubiquitination plays a key role in stress response and yield formation.
The yield per unit area of soybean is an emerging study focus in the world.
The ubiquitin‐proteasome system can be used to increase the soybean yield or stress resistance.
We proposed the strategy of applying the ubiquitin‐proteasome system in soybean improvement based on model plants.
Soybean cyst nematode (SCN) is a serious damaging disease in soybean worldwide. Peking- and PI 88788-type sources of resistance are two most important germplasm used in breeding resistant soybean ...cultivars against this disease. However, until now, no comparisons of constitutive resistances to soybean cyst nematode between these two types of sources had been conducted, probably due to the influences of different backgrounds. In this study, we used pooled-sample analysis strategy to minimize the influence of different backgrounds and directly compared the molecular mechanisms underlying constitutive resistance to soybean cyst nematode between these two types of sources
via
transcriptomic and metabolomic profilings. Six resistant soybean accessions that have identical haplotypes as Peking at
Rgh1
and
Rhg4
loci were pooled to represent Peking-type sources. The PI88788-type and control pools were also constructed in a same way. Through transcriptomic and metabolomics anaylses, differentially expressed genes and metabolites were identified. The molecular pathways involved in the metabolism of toxic metabolites were predicted to play important roles in conferring soybean cyst nematode resistance to soybean. Functions of two resistant candidate genes were confirmed by hairy roots transformation methods in soybean. Our studies can be helpful for soybean scientists to further learn about the molecular mechanism of resistance to soybean cyst nematode in soybean.
Li-SOCl2 batteries possess ultrahigh energy densities and superior safety features at a wide range of operating temperatures. However, the Li-SOCl2 battery system suffers from poor reversibility due ...to the sluggish kinetics of SOCl2 reduction during discharging and the oxidation of the insulating discharge products during charging. To achieve a high-power rechargeable Li-SOCl2 battery, herein we introduce the molecular catalyst I2 into the electrolyte to tailor the charging and discharging reaction pathways. The as-assembled rechargeable cell exhibits superior power density, sustaining an ultrahigh current density of 100 mA cm–2 during discharging and delivering a reversible capacity of 1 mAh cm–2 for 200 cycles at a current density of 2 mA cm–2 and 6 mAh cm–2 for 50 cycles at a current density of 5 mA cm–2. Our results reveal the molecular catalyst-mediated reaction mechanisms that fundamentally alter the rate-determining steps of discharging and charging in Li-SOCl2 batteries and highlight the viability of transforming a primary high-energy battery into a high-power rechargeable system, which has great potential to meet the ever-increasing demand of energy-storage systems.
Chalcogenides have been viewed as important conversion‐type Mg2+‐storage cathodes to fulfill the high volumetric energy density promise of magnesium (Mg) batteries. However, the low initial Columbic ...efficiency and the rapid capacity degradation remain challenges for the chalcogenide cathodes, as the clear Mg2+‐storage mechanism has yet to be clarified. Herein, we illustrate that the charge storage mechanism of the Cu2−xSe cathode is a reversible displacement reaction along with a polyselenide (PSe) mediated solution process of anion‐compensation. The unique anion redox improves charge storage, while the dissolution of PSe also leads to performance degradation. To address this issue, we introduce Mo6S8 into the Cu2−xSe cathode to immobilize PSe, which significantly improves performance, especially the reversible capacity (from 140 mAh g−1 to 220 mAh g−1). This work provides inspiration for the modification of the Mg2+‐storage cathode, which is a milestone for high‐performance Mg batteries.
The Mg2+‐storage mechanism underlying Cu2−xSe, a typical chalcogenide cathode, is a displacement reaction with anionic charge compensation, which is simultaneously accompanied by a polyselenide‐mediated dissolution process. The addition of Mo6S8 reduces the irreversible capacity and improves the electrochemical performance.
Chalcogenides have been viewed as important conversion-type Mg
-storage cathodes to fulfill the high volumetric energy density promise of magnesium (Mg) batteries. However, the low initial Columbic ...efficiency and the rapid capacity degradation remain challenges for the chalcogenide cathodes, as the clear Mg
-storage mechanism has yet to be clarified. Herein, we illustrate that the charge storage mechanism of the Cu
Se cathode is a reversible displacement reaction along with a polyselenide (PSe) mediated solution process of anion-compensation. The unique anion redox improves charge storage, while the dissolution of PSe also leads to performance degradation. To address this issue, we introduce Mo
S
into the Cu
Se cathode to immobilize PSe, which significantly improves performance, especially the reversible capacity (from 140 mAh g
to 220 mAh g
). This work provides inspiration for the modification of the Mg
-storage cathode, which is a milestone for high-performance Mg batteries.
Abstract
Chalcogenides have been viewed as important conversion‐type Mg
2+
‐storage cathodes to fulfill the high volumetric energy density promise of magnesium (Mg) batteries. However, the low ...initial Columbic efficiency and the rapid capacity degradation remain challenges for the chalcogenide cathodes, as the clear Mg
2+
‐storage mechanism has yet to be clarified. Herein, we illustrate that the charge storage mechanism of the Cu
2−
x
Se cathode is a reversible displacement reaction along with a polyselenide (PSe) mediated solution process of anion‐compensation. The unique anion redox improves charge storage, while the dissolution of PSe also leads to performance degradation. To address this issue, we introduce Mo
6
S
8
into the Cu
2−
x
Se cathode to immobilize PSe, which significantly improves performance, especially the reversible capacity (from 140 mAh g
−1
to 220 mAh g
−1
). This work provides inspiration for the modification of the Mg
2+
‐storage cathode, which is a milestone for high‐performance Mg batteries.
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