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De novo transcriptomic analyses revealed some detoxification genes and related pathways responsive to noposion yihaogong® 5% EC (Lambda-Cyhalothrin 5%) exposure in spodoptera frugiperda third-instar larvae
The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a polyphagous, invasive insect pest which causes significant losses in important crops wherever it has spread. The use of pesticides in agriculture is a key tool in the management of many important crop pests, including S. frugiperda, but continued use of insecticides has selected for various types of resistance, including enzyme systems that provide enhanced mechanisms of detoxification. In the present study, we analyzed the de novo transcriptome of S. frugiperda larvae exposed to Noposion Yihaogong® 5% emulsifiable concentrate (EC) insecticide focusing on detoxification genes and related pathways. Results showed that a total of 1819 differentially expressed genes (DEGs) were identified in larvae after being treated with Noposion Yihaogong® 5% EC insecticide, of which 863 were up- and 956 down-regulated. Majority of these differentially expressed genes were identified in numerous Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including metabolism of xenobiotics and drug metabolism. Furthermore, many of S. frugiperda genes involved in detoxification pathways influenced by lambda-cyhalothrin stress support their predicted role by further co-expression network analysis. Our RT-qPCR results were consistent with the DEG’s data of transcriptome analysis. The comprehensive transcriptome sequence resource attained through this study enriches the genomic platform of S. frugiperda, and the identified DEGs may enable greater molecular underpinnings behind the insecticide-resistance mechanism caused by lambda-cyhalothrin
Strategies towards enabling lithium metal in batteries: interphases and electrodes
Despite the continuous increase in capacity, lithium-ion intercalation batteries are approaching their performance limits. As a result, research is intensifying on next-generation battery technologies. The use of a lithium metal anode promises the highest theoretical energy density and enables use of lithium-free or novel high-energy cathodes. However, the lithium metal anode suffers from poor morphological stability and Coulombic efficiency during cycling, especially in liquid electrolytes. In contrast to solid electrolytes, liquid electrolytes have the advantage of high ionic conductivity and good wetting of the anode, despite the lithium metal volume change during cycling. Rapid capacity fade due to inhomogeneous deposition and dissolution of lithium is the main hindrance to the successful utilization of the lithium metal anode in combination with liquid electrolytes. In this perspective, we discuss how experimental and theoretical insights can provide possible pathways for reversible cycling of twodimensional lithium metal. Therefore, we discuss improvements in the understanding of lithium metal nucleation, deposition, and stripping on the nanoscale. As the solid–electrolyte interphase (SEI) plays a key role in the lithium morphology, we discuss how the proper SEI design might allow stable cycling. We highlight recent advances in conventional and (localized) highly concentrated electrolytes in view of their respective SEIs. We also discuss artificial interphases and three-dimensional host frameworks, which show prospects of mitigating morphological instabilities and suppressing large shape change on the electrode level
Facile solution-phase synthesis of γ-Mn3O4 hierarchical structures
<p>Abstract</p> <p>Background</p> <p>A lot of effort has been focused on the integration of nanorods/nanowire as building blocks into three-dimensional (3D) complex superstructures. But, the development of simple and effective methods for creating novel assemblies of self-supported patterns of hierarchical architectures to designed materials using a suitable chemical method is important to technology and remains an attractive, but elusive goal.</p> <p>Results</p> <p>The hierarchical structure of Mn<sub>3</sub>O<sub>4 </sub>with radiated spherulitic nanorods was prepared via a simple solution-based coordinated route in the presence of macrocycle polyamine, hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (CT) with the assistance of thiourea as an additive.</p> <p>Conclusion</p> <p>This approach opens a new and facile route for the morphogenesis of Mn<sub>3</sub>O<sub>4 </sub>material and it might be extended as a novel synthetic method for the synthesis of other inorganic semiconducting nanomaterials such as metal chalcogenide semiconductors with novel morphology and complex form, since it has been shown that thiourea can be used as an effective additive and the number of such water-soluble macrocyclic polyamines also makes it possible to provide various kinds of ligands for different metals in homogeneous water system.</p
Theoretically-Efficient and Practical Parallel DBSCAN
The DBSCAN method for spatial clustering has received significant attention
due to its applicability in a variety of data analysis tasks. There are fast
sequential algorithms for DBSCAN in Euclidean space that take work
for two dimensions, sub-quadratic work for three or more dimensions, and can be
computed approximately in linear work for any constant number of dimensions.
However, existing parallel DBSCAN algorithms require quadratic work in the
worst case, making them inefficient for large datasets. This paper bridges the
gap between theory and practice of parallel DBSCAN by presenting new parallel
algorithms for Euclidean exact DBSCAN and approximate DBSCAN that match the
work bounds of their sequential counterparts, and are highly parallel
(polylogarithmic depth). We present implementations of our algorithms along
with optimizations that improve their practical performance. We perform a
comprehensive experimental evaluation of our algorithms on a variety of
datasets and parameter settings. Our experiments on a 36-core machine with
hyper-threading show that we outperform existing parallel DBSCAN
implementations by up to several orders of magnitude, and achieve speedups by
up to 33x over the best sequential algorithms
Space advanced technology demonstration satellite
The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of similar to 500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance
Understanding isolated lithium formation in lithium metal batteries with liquid electrolytes
Lithium metal batteries (LMBs) with liquid electrolytes are promising candidates for next-generation high-energy-density batteries, currently limited by their cyclability [1]. A main cause for the low cycle life of LMBs is the non-reversible stripping of lithium during discharge [2]. Lithium gets isolated from the current collector and trapped in the insulating remaining solid-electrolyte interphase (SEI) shell [2,3]. However, a fundamental understanding of this process and the stripping dynamics remain elusive. We performed a combined theoretical and experimental study to understand isolated lithium formation during stripping [4]. We derive a thermodynamically consistent model of lithium dissolution underneath the SEI to predict the stripping dynamics of lithium during dissolution. We probe our predictions by resolving the structures after stripping with cryogenic transmission electron microscopy (TEM). We find that locally preferred stripping occurs due to the interaction with lithium and the SEI, which leads to isolated lithium formation. The cryo TEM results reveal that these local effects are particularly pronounced at kinks of lithium whiskers. Heterogeneous SEI, heterogeneous stress fields, or the geometric shape of the deposits can cause these local effects. Further, the amount of isolated lithium formation depends on the operating conditions, where higher stripping current densities lead to less isolated lithium. We conclude that in order to fully mitigate isolated lithium, a planar lithium morphology and a homogeneous SEI must be achieved.
Literature:
[1] Horstmann, B., Shi, J., Amine, R., Werres, M., et al. Energy Environ. Sci. 14, 5289-5314 (2021), [2] Fang, C. et al. Nature 572, 511-515 (2019), [3] Steiger, J., Kramer, D. & Mönig, R. J. Power Sources 261, 112-119 (2014), [4] Werres, M., Xu, Y., Hao, J., Wu, X., Wang, C., Latz, A. & Horstmann, B. arXiv:2301.04018 (2023
Origin of heterogeneous stripping of lithium in liquid electrolytes
Lithium metal batteries suffer from low cycle life. During discharge, parts of the lithium are not stripped reversibly and remain isolated from the current collector. This isolated lithium is trapped in the insulating remaining solid-electrolyte interphase (SEI) shell and contributes to the capacity loss. However, a fundamental understanding of why isolated lithium forms and how it can be mitigated is lacking. In this article, we perform a combined theoretical and experimental study to understand isolated lithium formation during stripping. We derive a thermodynamic consistent model of lithium dissolution and find that the interaction between lithium and SEI leads to locally preferred stripping and isolated lithium formation. Based on a cryogenic transmission electron microscopy (cryo TEM) setup, we reveal that these local effects are particularly pronounced at kinks of lithium whiskers. We find that lithium stripping can be heterogeneous both on a nanoscale and on a larger scale. Cryo TEM observations confirm our theoretical prediction that isolated lithium occurs less at higher stripping current densities. The origin of isolated lithium lies in local effects, such as heterogeneous SEI, stress fields, or the geometric shape of the deposits. We conclude that in order to mitigate isolated lithium, a uniform lithium morphology during plating and a homogeneous SEI are indispensable
Behaviour of Lithium During Stripping - Isolated Lithium Formation
Lithium metal (Li) batteries are promising candidates for next-generation high-energy density batteries, yet they suffer from low cycle life [1]. It is commonly observed that Li gets isolated from the current collector during cycling, diminishing the available capacity [2]. This isolated lithium is trapped in an insulating solid-electrolyte interphase (SEI) shell [2,3]. However, a fundamental understanding of how Li gets isolated is still lacking. Here, we present a combined experimental and theoretical study to uncover the origin of isolated Li formation [4]. We derive a thermodynamic consistent model for stripping of a single Li whisker, accounting for the interaction between Li and SEI. We find that this interaction leads to locally preferred stripping and isolated Li formation upon further stripping. Cryo transmission electron microscopy investigations of Li whiskers during stripping reveal that these local effects are pronounced at kinks and the tip of Li whiskers. Sources for heterogeneity can be locally varying geometry or heterogeneous SEI. Further, simulations reveal that higher stripping current densities lead to less isolated Li formation. This can be understood in terms of the auto-inhibitory behaviour of the stripping process, where the instability is suppressed above a critical current [5]. We conclude that isolated Li can only be fully avoided when Li-deposition is planar, and the SEI is homogeneous.
References
[1] B. Horstmann, et al., "Strategies towards enabling lithium metal in batteries: interphases and electrodes", Energy Environ. Sci., vol. 14, pp. 5289-5314, 2021.
[2] C. Fang, et al., "Quantifying inactive lithium in lithium metal batteries", Nature, vol. 572, pp. 511-515, 2019.
[3] J. Steiger, D. Kramer, & R. Mönig, "Microscopic observations of the formation, growth and shrinkage of lithium moss during electrodeposition and dissolution", Electrochim. Acta, vol. 136, pp. 529-536, 2014.
[4] M. Werres et al. "Origin of heterogeneous stripping of lithium in liquid electrolytes", arXiv: 2301.04018v1, 2023.
[5] M.Z. Bazant, "Thermodynamic stability of driven open systems and control of phase separation by electro-autocatalysis", Faraday Discuss., vol. 199, pp. 423-463, 2017
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