Search

The addition of electrolyte additives shows significant effect on the low temperature performance of lithium-ion batteries (LIBs), but the underlying mechanism remains to be further elucidated and understood. Here, we take methyl acetate (MA) as an example to explore the mechanism of low-temperature additives on the graphite interface. The effects of the MA additive, demonstrated by scanning electrochemical microscopy (SECM) and atomic force microscopy, optimize the electron insulating properties and mechanical properties of the graphite anode. This optimized electrolyte improves the graphite performance with a capacity of 343.8 mA h g−1 after 300 cycles at room temperature and 302.9 mA h g−1 at low temperature (−10 °C), while the capacity decreases sharply without MA, and at the same time improves the rate performance which increases the capacity retention at 4C from 18% to 55%. The reinforced electronic insulation SEI is observed in the first discharge process with MA addition in SECM feedback mode and remains stable in the next cycles. The results show that a stable ultrathin SEI with an inorganic/organic bilayer structure rapidly forms in the first cycle with MA addition, the outer organic layer provides mechanical suppression and the inner inorganic layer promotes the interface mechanical strength with excellent ion transport, which suppresses the continuous decomposition of electrolytes and improves the mechanical properties of the SEI. [ABSTRACT FROM AUTHOR]

Plants have evolved tightly regulated signaling networks to respond and adapt to environmental perturbations, but the nature of the signaling hub(s) involved have remained an enigma. We have previously established that methylerythritol cyclodiphosphate (MEcPP), a precursor of plastidial isoprenoids and a stress-specific retrograde signaling metabolite, enables cellular readjustments for high-order adaptive functions. Here, we specifically show that MEcPP promotes two Brassicaceae-specific traits, namely endoplasmic reticulum (ER) body formation and induction of indole glucosinolate (IGs) metabolism selectively, via transcriptional regulation of key regulators NAI1 for ER body formation and MYB51/122 for IGs biosynthesis). The specificity of MEcPP is further confirmed by the lack of induction of wound-inducible ER body genes as well as IGs by other altered methylerythritol phosphate pathway enzymes. Genetic analyses revealed MEcPP-mediated COI1-dependent induction of these traits. Moreover, MEcPP signaling integrates the biosynthesis and hydrolysis of IGs through induction of nitrile-specifier protein1 and reduction of the suppressor, ESM1, and production of simple nitriles as the bioactive end product. The findings position the plastidial metabolite, MEcPP, as the initiation hub, transducing signals to adjust the activity of hard-wired gene circuitry to expand phytochemical diversity and alter the associated subcellular structure required for functionality of the secondary metabolites, thereby tailoring plant stress responses.

Despite the growing number of studies showing that genotype × environment and epistatic interactions control fitness, the influences of epistasis × environment interactions on adaptive trait evolution remain largely uncharacterized. Across three field trials, we quantified aliphatic glucosinolate (GSL) defense chemistry, leaf damage, and relative fitness using mutant lines of Arabidopsis thaliana varying at pairs of causal aliphatic GSL defense genes to test the impact of epistatic and epistasis × environment interactions on adaptive trait variation. We found that aliphatic GSL accumulation was primarily influenced by additive and epistatic genetic variation, leaf damage was primarily influenced by environmental variation and relative fitness was primarily influenced by epistasis and epistasis × environment interactions. Epistasis × environment interactions accounted for up to 48% of the relative fitness variation in the field. At a single field site, the impact of epistasis on relative fitness varied significantly over 2 yr, showing that epistasis × environment interactions within a location can be temporally dynamic. These results suggest that the environmental dependency of epistasis can profoundly influence the response to selection, shaping the adaptive trajectories of natural populations in complex ways, and deserves further consideration in future evolutionary studies.

BREVIPEDICELLUS (BP) encodes a class-I KNOTTED1-like homeobox (KNOX) transcription factor that plays a critical role in conditioning a replication competent state in the apical meristem, and it also governs growth and cellular differentiation in internodes and pedicels. To search for factors that modify BP signaling, we conducted a suppressor screen on bp er (erecta) plants and identified a mutant that ameliorates many of the pleiotropic defects of the parent line. Map based cloning and complementation studies revealed that the defect lies in the FILAMENTOUS FLOWER (FIL) gene, a member of the YABBY family of transcriptional regulators that contribute to meristem organization and function, phyllotaxy, leaf and floral organ growth and polarity, and are also known to repress KNOX gene expression. Genetic and cytological analyses of the fil-10 suppressor line indicate that the role of FIL in promoting growth is independent of its previously characterized influences on meristem identity and lateral organ polarity, and likely occurs non-cell-autonomously from superior floral organs. Transcription profiling of inflorescences revealed that FIL downregulates numerous transcription factors which in turn may subordinately regulate inflorescence architecture. In addition, FIL, directly or indirectly, activates over a dozen genes involved in glucosinolate production in part by activating MYB28, a known activator of many aliphatic glucosinolate biosynthesis genes. In the bp er fil-10 suppressor mutant background, enhanced expression of CYP71A13, AMIDASE1 (AMI) and NITRILASE genes suggest that auxin levels can be modulated by shunting glucosinolate metabolites into the IAA biosynthetic pathway, and increased IAA levels in the bp er fil-10 suppressor accompany enhanced internode and pedicel elongation. We propose that FIL acts to oppose KNOX1 gene function through a complex regulatory network that involves changes in secondary metabolites and auxin.

The development of all-group IV GeSn materials on Si substrates is of interest for monolithic midwave infrared (MWIR) silicon photonics. Despite their great potential, the growth of high crystalline quality materials is still challenging. The conventional growth of GeSn films on Si displays high densities of dislocations and, hence, large dark currents. We have examined a state-of-the-art lithographically defined aspect ratio trapping (ART) growth approach for threading dislocations (TDs) filtering in GeSn and demonstrated the selective growth in the holes embedded in the SiO2/Si(001) template. While an exceptionally low density of TDs was confirmed by transmission electron microscopy imaging, we find that Sn incorporation is strongly suppressed in the ART-grown structures. Nonetheless, these results provide a solid basis for further efforts to enhance the Sn fraction of the GeSn ART growth. [ABSTRACT FROM AUTHOR]

A combined experimental and numerical research study is conducted to investigate the complex relationship between the structure and the aerodynamic performances of an Archimedes spiral wind turbine (ASWT). Two ASWTs are considered, a prototypical version and an improved version. It is shown that the latter achieves the best aerodynamic performance when the spread angles at the three sets of blades are α1 = 30°, α2 = 55°, α3 = 60°, respectively and the blade thickness is 4 mm. For a velocity V = 10 m/s, a tip speed ratio (TSR) = 1.58 and 2, the maximum CP values are 0.223 and 0.263 for the prototypical ASWT and improved ASWT, respectively, and the maximum CP enhancement is 17.93%. For V = 10 m/s and TSR = 2, the CP values of the prototypical ASWT and improved ASWT are 0.225 and 0.263, respectively, with an aerodynamic performance enhancement of 16.88%. Through mutual verification of the test outcomes and numerical results, it is concluded that the proposed approach can effectively lead to aerodynamic performance improvement. [ABSTRACT FROM AUTHOR]

High-quality monolithic Ge-on-Si is sought for CMOS-compatible optoelectronic devices. We examine the structural characteristics of Ge-on-Si grown by the aspect ratio trapping (ART) method on a SiO2/Si(001) template in pre-patterned holes. Transmission electron microscopy and surface topography analysis revealed high-quality Ge islands overgrown from the ART holes in SiO2. The superior crystal quality of Ge ART growth was also confirmed by comparing x-ray diffraction (XRD) data of Ge ART and Ge planar epilayer samples. The XRD and micro-Raman data additionally show a small residual strain in the islands which vanishes by reducing the hole diameter from 280 nm to 180 nm, while leading to only a minor increase in the crystallographic inclinations of the Ge islands from 0.34 deg to 0.54 deg. With finite element method simulations, we find that the small residual strain in Ge originates during the cool-down from growth to room temperature because of thermal expansion coefficient mismatch between Ge and SiO2. A tensile force develops along the [001] axis of the Ge pillar whose faster shrinkage to the room temperature volume is restricted by the oversized surface island. [ABSTRACT FROM AUTHOR]

Calcium‐ion batteries (CIBs) are considered as potential next‐generation energy storage systems due to their abundant reserves and relatively low cost. However, irreversible structural changes and weak conductivity still hinder in current CIBs cathode materials. Herein, an organic molecular intercalation strategy is proposed, in which V2O5 regulated with quinoline, pyridine, and water molecules are studied as cathode material to provide fast ion diffusion channels, large storage host, and high conductivity for Ca ions. Among them, V2O5‐quinoline (QVO) owns the largest interplanar spacing of 1.25 nm and the V‐O chains are connected with organic molecular by hydrogen bond, which stabilizes the crystal structure. As a result, QVO exhibits a specific capacity of 168 mAh g−1 at 1 A g−1 and capacity retention of 80% after 500 cycles at 5 A g−1 than the other materials. Furthermore, X‐Ray diffraction and X‐ray absorption spectroscopy results reveal a reversible order‐disorder transformation mechanism of Ca2+ for QVO, which can make full use of the abundant active sites for high capacity and simultaneously achieve fast reaction kinetics for excellent rate performance. These results demonstrate that QVO is a promising cathode material for CIBs, providing more choices for the development of high‐performance CIBs. [ABSTRACT FROM AUTHOR]