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Hoon‐Hee Ryu Nam‐Yung Park Dae Ro Yoon Un‐Hyuck Kim Chong S. Yoon Yang‐Kook Sun 《Liver Transplantation》2020,10(25)
A new class of layered cathodes, Li[NixCoyB1?x?y]O2 (NCB), is synthesized. The proposed NCB cathodes have a unique microstructure in which elongated primary particles are tightly packed into spherical secondary particles. The cathodes also exhibit a strong crystallographic texture in which the a–b layer planes are aligned along the radial direction, facilitating Li migration. The microstructure, which effectively suppresses the formation of microcracks, improves the cycling stability of the NCB cathodes. The NCB cathode with 1.5 mol% B delivers a discharge capacity of 234 mAh g?1 at 0.1 C and retains 91.2% of its initial capacity after 100 cycles (compared to values of 229 mAh g?1 at 0.1 C and 78.8% for pristine Li[Ni0.9Co0.1]O2). This study shows the importance of controlling the microstructure to obtain the required cycling stability, especially for Ni‐rich layered cathodes, where the main cause of capacity fading is related to mechanical strain in their charged state. 相似文献
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Ju‐Myung Kim Jae‐Ho Park Eunmi Jo Hyung‐Seok Kim Seung‐Hyeok Kim Wonyoung Chang Kyung Yoon Chung Sang‐Young Lee 《Liver Transplantation》2020,10(9)
Despite their exceptionally high capacity, overlithiated layered oxides (OLO) have not yet been practically used in lithium‐ion battery cathodes due to necessary toxic/complex chemical activation processes and unsatisfactory electrochemical reliability. Here, a new class of ecofriendly chemical activation strategy based on amphiphilic deoxyribose nucleic acid (DNA)‐wrapped multiwalled carbon nanotubes (MWCNT) is demonstrated. Hydrophobic aromatic bases of DNA have a good affinity for MWCNT via noncovalent π–π stacking interactions, resulting in core (MWCNT)‐shell (DNA) hybrids (i.e., DNA@MWCNT) featuring the predominant presence of hydrophilic phosphate groups (coupled with Na+) in their outmost layers. Such spatially rearranged Na+–phosphate complexes of the DNA@MWCNT efficiently extract Li+ from monoclinic Li2MnO3 of the OLO through cation exchange reaction of Na+–Li+, thereby forming Li4Mn5O12‐type spinel nanolayers on the OLO surface. The newly formed spinel nanolayers play a crucial role in improving the structural stability of the OLO and suppressing interfacial side reactions with liquid electrolytes, eventually providing significant improvements in the charge/discharge kinetics, cyclability, and thermal stability. This beneficial effect of the DNA@MWCNT‐mediated chemical activation is comprehensively elucidated by an in‐depth structural/electrochemical characterization. 相似文献
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Romain Pigeaud 《L'Anthropologie》2002,106(4):445
The decorated cave of Mayenne-Sciences (Thorigné-en-Charnie, Mayenne) is one of the eight caves or shelters attributed to the Upper Paleolithic in the North of France, with the caves of Gouy and Orival in Normandy, Boutigny, Le Croc-Marin and Les Trois Pignons in the Essonne Department, the Grotte du Cheval and the Grande Grotte of Arcy-sur-Cure in Burgundy. There are about 50 stylised representations in this cave, the chrono-cultural attribution is rather difficult because the archeological context is poor and the site of the cave excentric, far from the great areas like Perigord. After a short statement of what you may guess about the style of the representations in Mayenne-Sciences we try to draw up a synthesis of the sites of parietal art and furniture near Mayenne-Sciences, and to analyse further how to place Mayenne-Sciences within a figurative tendance flourishing during the ante-magdalenian era in Europe which we propose to call art de la silhouette. We show that the style of Mayenne-Sciences is not 50 particular, but that the originality of the style may be explained by the isolation of the cave at the border of the main prehistorical cultural tendances, as this is the case for other decorated caves, we list up. In conclusion this leads us to define the concept of grotte-limite (border-cave), I mean a decorated cave which represents the vision at distance, with caricatural character or not, of the parietal art of one specific region, as for example you must admit that there are similitude’s between Mayenne-Sciences and the caves of Pech-Merle and Cougnac, in the Lot Department. 相似文献
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In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu–Mg–Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene–gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene–gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150 μg/L. The detection limit for chlorpyrifos was 0.05 μg/L. 相似文献
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Electrodes: Layered P2/O3 Intergrowth Cathode: Toward High Power Na‐Ion Batteries (Adv. Energy Mater. 17/2014) 下载免费PDF全文