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Wenwei Feng,&ast; Jiancong Zhou,&ast; Zhubin Lun, Dianhua Zhou, Peiwen Li, Jianfeng Ye Department of Cardiology, Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, Guangdong, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jianfeng Ye, Department of Cardiology, Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, Guangdong, People’s Republic of China, Email yipjf@hotmail.comBackground: Contrast-associated acute kidney injury (CA-AKI) is a prevalent complication following coronary angiography (CAG). However, there is ongoing controversy surrounding its precise definition. Although previous studies have demonstrated the successful application of appropriate definitions in managing high-risk CA-AKI patients, there remains limited research on the association between different definitions and prognosis specifically in patients with chronic kidney disease (CKD).Methods: A total of 4197 CKD patients undergoing coronary angiography (CAG) were included in this study. Two definitions of contrast-associated acute kidney injury (CA-AKI) were used: CA-AKIA, which was defined as an increase of ≥ 0.5 mg/dL or > 25% in serum creatinine (SCr) from baseline within 72 hours after CAG, and CA-AKIB, which was defined as an increase of ≥ 0.3 mg/dL or > 50% in SCr from baseline within 48 hours after CAG. Cox regression analysis was employed to assess the association between these two definitions and long-term mortality. Additionally, population attributable risks (PARs) were calculated to evaluate the impact of CA-AKI definitions on long-term prognosis.Results: During the median follow-up period of 4.70 (2.50– 7.78) years, the overall long-term mortality was 23.6%, and the long-term mortality in patients with CA-AKI according to both CA-AKIA and CA-AKIB criteria were 33.5% and 33.8%, respectively. We found that CA-AKIA (HR: 1.45, 95% CI: 1.23– 1.70, p< 0.001) and CA-AKIB (HR: 1.44, 95% CI: 1.23– 1.69, p< 0.001) were associated with long-term mortality. The PARs were the highest for CA-AKIA (5.87%), followed by CA-AKIB (5.70%).Conclusion: Contrast-associated acute kidney injury (CA-AKI) is a frequently observed complication in CKD patients undergoing coronary angiography (CAG), and both definitions of CA-AKI are significantly correlated with a poor long-term prognosis. Consequently, in the clinical management of CKD patients, it is crucial to prioritize CA-AKI, irrespective of the specific CA-AKI definition used.Keywords: contrast-associated acute kidney injury, chronic kidney disease, definitions, long-term mortality, population attributable risks

Cation-disordered rocksalt (DRX) materials have emerged as a class of novel high-capacity cathodes for Li-ion batteries. However, the commercialization of DRX cathodes will require reducing their capacity decay, which has been associated with oxygen loss during cycling. Recent studies show that fluorination of DRX cathodes can effectively reduce oxygen loss and improve cycling stability; however, the underlying atomic-scale mechanisms remain elusive. Herein, using a combination of electrochemical measurements, scanning transmission electron microscopy, and electron energy loss spectroscopy, the correlation between the electrochemical properties and structural evolution in Mn-redox-based DRX cathodes, Li1.2Ti0.4–xMn0.4+xO2.0-xFx (x = 0 and 0.2) is examined. It is found that fluorination strongly suppresses structural amorphization and void formation initiated from the particle surface, therefore greatly enhancing the cyclability of the cathode. A novel rocksalt-to-spinel-like structural transformation in the DRX bulk is further revealed, which surprisingly contributes to a gradual capacity increase during cycling. The results provide important insight for the design of novel DRX cathodes with high capacity and long cycle life.

Using both computations and experiments, we demonstrate that the performance of Li-excess cation-disordered rocksalt cathodes can be improved by Mg substitution. Mg reduces the amount of Li in the compound that is strongly bound to F and thereby increases the capacity. This enables the use of fluorination as a tool to improve stability of the compounds without significant loss of capacity. Mg emerged as the most optimal substitution element from a systematic computational study aimed at identifying inactive doping elements with a strong enough bonding strength to fluorine to displace Li from the F environments. Our results also show that capacity can be traded for cycle life depending on whether Mg is substituted for Li or for the redox metal. This design strategy should be considered in fluorinated cathodes, which will facilitate the design of optimized disordered rocksalt oxyfluoride cathodes.

Li-excess cation-disordered rocksalt (DRX) oxides have shown potential as high-energy-density Li-ion cathodes. They typically exploit O redox to achieve high capacity, which can trigger oxygen loss at the surface, thereby affecting the cathode performance. Here, we elucidate the impact that the surface structural evolution has on their electrochemical properties by comparing two prototypical DRX cathodes, Li1.2Ni0.333Ti0.333Mo0.133O2 (LNTMO) and Li1.2Mn0.6Nb0.2O2 (LMNO). Both cathodes achieve high capacity, but oxygen loss leads to significant polarization for LNTMO, whereas LMNO is far less affected. We show that while metal densification at the particle surface occurs for both materials, the resulting surface structure is strikingly different. A spinel phase forms at the surface of LMNO, which effectively alleviates oxygen loss and allows fast Li transport, whereas a densified DRX forms at the LNTMO surface, which impedes Li transport and cannot mitigate oxygen loss. These findings demonstrate the importance of the surface structure of DRX cathode.

Fluorine substitution is a critical enabler for improving the cycle life and energy density of disordered rocksalt (DRX) Li-ion battery cathode materials which offer prospects for high energy density cathodes, without the reliance on limited mineral resources. Due to the strong Li–F interaction, fluorine also is expected to modify the short-range cation order in these materials which is critical for Li-ion transport. In this work, density functional theory and Monte Carlo simulations are combined to investigate the impact of Li–F short-range ordering on the formation of Li percolation and diffusion in DRX materials. The modeling reveals that F substitution is always beneficial at sufficiently high concentrations and can, surprisingly, even facilitate percolation in compounds without Li excess, giving them the ability to incorporate more transition metal redox capacity and thereby higher energy density. It is found that for F levels below 15%, its effect can be beneficial or disadvantageous depending on the intrinsic short-range order in the unfluorinated oxide, while for high fluorination levels the effects are always beneficial. Using extensive simulations, a map is also presented showing the trade-off between transition-metal capacity, Li-transport, and synthetic accessibility, and two of the more extreme predictions are experimentally confirmed.

For lithium-ion rechargeable batteries to meet society's ever-growing demands in electrical energy storage, e.g. for the electrification of transportation, for portable electronics and for grid storage applications, novel electrode materials with a large charge storage capacity and a high energy density are needed. Over the last five years, several experimental and theoretical studies have demonstrated the feasibility of disordered rocksalt (DRX) cathodes, that is, lithium transition metal oxide cathodes with a crystalline rocksalt structure but with a disordered arrangement of lithium and transition metal on the cation lattice. We provide here an overview of the current understanding of DRX materials, in terms of their structural and compositional characteristics, as well as their electrochemical properties. We also present important considerations for the design of high performance DRX cathodes and suggest future research directions. Because no specific order is needed, DRX compounds can be composed of a wide variety of transition metal species, which can create long-term benefits for the lithium battery industry by making it less reliant on scarce and expensive raw materials. While some DRX compositions can simply be synthesized at high temperature to induce thermal cation disorder, other compositions require mechanochemical methods to induce a disordered arrangement of cation species. Cation disorder leads to unique lithium transport properties, small volume changes during charge-discharge cycling and sloping electrochemical profiles. Fluorine substitution for oxygen and the incorporation of high-valent d0 transition metals in the bulk DRX structure are two strategies used to increase the lithium content in the material, improve lithium percolation and to keep the valence of redox-active metal species low so that high transition metal redox capacity can be obtained. Short-range cation order, which is affected by thermal treatment, metal composition and fluorine substitution, has a significant impact on electrochemical performance. Moreover, fluorine substitution for oxygen improves long-term capacity retention by significantly reducing anion-based charge compensation mechanisms during charge. Fluorinated DRXs have recently demonstrated reversible capacities >300 mA h g-1 and extremely high energy densities approaching 1000 W h kg-1, holding promise for a nearly two-fold increase in the energy density of commercial lithium-ion batteries.

Mn-based Li-excess cation-disordered rocksalt (DRX) oxyfluorides are promising candidates for next-generation rechargeable battery cathodes owing to their large energy densities, the earth abundance, and low cost of Mn. In this work, we synthesized and electrochemically tested four representative compositions in the Li-Mn-O-F DRX chemical space with various Li and F content. While all compositions achieve higher than 200 mAh g−1 initial capacity and good cyclability, we show that the Li-site distribution plays a more important role than the metal-redox capacity in determining the initial capacity, whereas the metal-redox capacity is more closely related to the cyclability of the materials. We apply these insights and generate a capacity map of the Li-Mn-O-F chemical space, LixMn2-xO2-yFy (1.167 ≤ x ≤ 1.333, 0 ≤ y ≤ 0.667), which predicts both accessible Li capacity and Mn-redox capacity. This map allows the design of compounds that balance high capacity with good cyclability.

In cation-disordered rocksalt Li-ion cathode materials, an excess of Li with respect to the transition metal content is necessary for the creation of percolating pathways for Li transport. Because of the lower amount of redox-active transition metal, a substantial part of the charge transfer must occur via less reversible oxygen redox. Fluorination can be used to minimize this dependence on oxygen redox by increasing the amount of low-valent transition metal in the compound, but it adds complexity to materials design. Here, we investigate the feasibility of using computationally constructed phase diagrams to facilitate the search for optimal oxyfluorides. We use the phase diagram of LiF-Li3NbO4-NiO to identify Li1.13Ni0.57Nb0.3O1.75F0.25 and Li1.19Ni0.59Nb0.22O1.46F0.54 as two promising compositions and demonstrate that they can be successfully synthesized. These compounds exhibit significantly reduced hysteresis and higher energy density than the previously reported Li1.3Ni0.27Nb0.43O2 compound in this space. Although we generally attribute the improved performance to the increased Ni content enabled by fluorination, a more nuanced relation between fluorination and the cycling behavior is revealed through electrochemical tests, X-ray absorption spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and density functional theory. We find that fluorination increases the voltage, improves cycle life, but reduces the accessibility of Ni redox. Consideration of these effects will facilitate the future design of optimized disordered-rocksalt oxyfluoride cathodes.

The discovery of facile Li transport in disordered, Li-excess rocksalt materials has opened a vast new chemical space for the development of high energy density, low cost Li-ion cathodes. We develop a strategy for obtaining optimized compositions within this class of materials, exhibiting high capacity and energy density as well as good reversibility, by using a combination of low-valence transition metal redox and a high-valence redox active charge compensator, as well as fluorine substitution for oxygen. Furthermore, we identify a new constraint on high-performance compositions by demonstrating the necessity of excess Li capacity as a means of counteracting high-voltage tetrahedral Li formation, Li-binding by fluorine and the associated irreversibility. Specifically, we demonstrate that 10-12% of Li capacity is lost due to tetrahedral Li formation, and 0.4-0.8 Li per F dopant is made inaccessible at moderate voltages due to Li-F binding. We demonstrate the success of this strategy by realizing a series of high-performance disordered oxyfluoride cathode materials based on Mn2+/4+ and V4+/5+ redox.

In order to improve the energy utilization of rotary hearth furnace (RHF), some methods were raised to solve the problem. Through changing the inlet angle of the nozzle, a higher and more uniform temperature field can be got. Thus, the burden in the furnace can be heated to the reduction temperature in a relatively shorter time. By using multilayer pellets technology, the energy can be utilized as much as possible. However, the top layer pellets would be reoxidized when the middle and bottom layer pellets were reduced. The average metallization of the reduced pellets get the maximum value at 25 min, which is consistent with the reality operation.

A detailed analysis of the low-frequency noise characteristics of the thin-film SIMOX SOI MOSFET is presented. It is observed that local potential fluctuations are caused by the random generation- recombination (G-R) process.

To study the periodically time-varying dynamic characteristics of static eccentric squeeze film damper (SFD), two models of computational fluid dynamics were established by dynamic mesh method of transient flow field. Numerical investigation was carried out for periodically time-varying dynamic characteristics of static eccentric SFD and the results were verified by theoretical formulas. As shown by the study, due to the presence of static eccentricity, oil-film damping and stiffness present distinct periodically time-varying characteristics with precession angle and their peak values occur in different circumferential positions; excessive static eccentricity will significantly alter the distribution of oil film pressure and direction of radial force of oil film. For SFD in practice, when dynamic eccentricity is smaller, the periodically time-varying characteristics are subjected to the dual influence of oil supply hole and static eccentricity. With the augment of dynamic eccentricity, the influence from oil supply hole is reduced, and the periodically time-varying characteristics are mainly embodied as the influence of static eccentricity. [ABSTRACT FROM AUTHOR]