Surface in-situ reconstruction of LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode materials interacting with antimony compounds and the electrochemical performances

Abstract(#br)Interfacial stability is regarded as one of the greatest challenges in the commercialization of Ni-rich layered cathode materials for lithium battery. Surface modification can solve these issues to obtain superior electrochemical performances. Herein, LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode surface is reconstructed by a simple solid-state method using antimony oxides as modified agents. The modified mechanisms study show that the antimony oxides (Sb 2 O 5 ) can react with the surface lithium residues effectively and partial surface lattice lithium on the NCM811 surface to further construct the LiSbO 3 /Li–Sb– Me –O ( Me = Ni, Co, Mn) mixed coating layers. The uniform coating layer is mainly ascribed to the droplet spreading behaviors of the low smelting antimony oxides. The electrochemical measurements show that the Sb-modified NCM811 electrodes deliver 90.27% (180 mA g −1 ) and 96.07% (1440 mA g −1 ) capacity retentions over 3.0–4.3 V after 200 cycles, respectively, which are higher than 77.40 and 74.75% of the bare NCM811. The enhanced electrochemical performances are mainly benefitted to the enhanced the lithium transportation, the suppressed impedances increase and the more stable crystal structure

Ethnic disparities and temporal trends in health resource allocation: a retrospective decadal analysis in Sichuan, a multi-ethnic Province of Southwest China (2009–2019)

Abstract Background Research on health resource allocation trends in ethnic minority and impoverished areas in China is limited since the 2009 Medical Reform. This study aimed to investigate the variations and inequalities in health resource distribution among ethnic minority, poverty-stricken, and non-minority regions in Sichuan Province, a multi-ethnic province in Southwest China, from 2009 to 2019. Methods The numbers of beds, doctors and nurses were retrospectively sourced from the Sichuan Health Statistics Yearbook between 2009 and 2019. All the 181 counties in Sichuan Province were categorized into five groups: Yi, Zang, other ethnic minority, poverty-stricken, and non-minority county. The Theil index, adjusted for population size, was used to evaluate health resource allocation inequalities. Results From 2009 to 2019, the number of beds (Bedp1000), doctors (Docp1000), and nurses (Nurp1000) per 1000 individuals in ethnic minority and poverty-stricken counties consistently remained lower than non-minority counties. The growth rates of Bedp1000 in Yi (140%) and other ethnic minority counties (127%) were higher than in non-minority counties (121%), while the growth rates of Docp1000 in Yi (20%) and Zang (11%) counties were lower than non-minority counties (61%). Docp1000 in 33% and 50% of Yi and Zang ethnic counties decreased, respectively. Nurp1000 in Yi (240%) and other ethnic minority (316%) counties increased faster than non-minority counties (198%). The Theil index for beds and nurses declined, while the index for doctors increased. Key factors driving increases in bed allocation include preferential policies and economic development levels, while health practitioner income, economic development levels and geographical environment significantly influence doctor and nurse allocation. Conclusions Preferential policies have been successful in increasing the number of beds in health facilities, but not healthcare workers, in ethnic minority regions. The ethnic disparities in doctor allocation increased in Sichuan Province. To increase the number of doctors and nurses in ethnic minority and poverty-stricken regions, particularly in Yi counties, more preferential policies and resources should be introduced

Multi-Objective Material Logistics Planning with Discrete Split Deliveries Using a Hybrid NSGA-II Algorithm

To schedule material supply intelligently and meet the production demand, studies concerning the material logistics planning problem are essential. In this paper, we consider the problem based on the scenario that more than one vehicle may visit each station in batches. The primary objective is to satisfy the demands in the time windows, followed by logistics planning with the minimum vehicles and travel time as the optimization objective. We construct a multi-objective mixed-integer programming model for the scenario of discrete material supply in workshops. First, we propose a hybrid heuristic algorithm combining NSGA-II and variable neighborhood search. This proposed algorithm combines the global search capability of NSGA-II and the strong local search capability, which can balance intensification and diversification well. Second, to maintain the diversity of population, we design the population diversity strategy and various neighborhood operators. We verify the effectiveness of the hybrid algorithm by comparing with other algorithms. To test the validity of the proposed problem, we have carried out research and application in a construction machinery enterprise

Surface properties of V 40(TiCr) 51Fe 8Mn alloy during hydrogenation/dehydrogenation cycles

The bcc alloy V40(TiCr)51Fe8Mn shows a high reversible hydrogen capacity of 2.22 mass% at room temperature and is therefore expected to be applied as a hydrogen storage material. During the first 10 hydrogenation/dehydrogenation cycles, the capacity decreases markedly from 2.22 to 1.86 mass%. Possible reasons are both internal (including lattice variation, strain, phase transformation, phase disproportion, etc.) and external factors (poisoning by impurities in the gas after decades of cycles mainly). In this work, the surface properties of the V40(TiCr) 51Fe8Mn alloy during 20 hydrogenation/dehydrogenation cycles were investigated by XPS analysis. During hydrogenation/dehydrogenation cycles, the surface becomes oxidized. Particular oxides were known to block hydrogen uptake and might thus be responsible for the capacity decay. It was found that Cr is enriched at the surface. Dense and passive chromia forms thereafter around alloy particles and hinder further oxidation and therefore stops further degradation of the hydrogen capacity of the alloy. © 2013 Elsevier B.V. All rights reserved

α-Synuclein Aggregates in the Nigro-Striatal Dopaminergic Pathway Impair Fine Movement: Partial Reversal by the Adenosine A_2A Receptor Antagonist

Parkinson’s disease (PD) is characterized pathologically by abnormal aggregation of alpha-synuclein (α-Syn) in the brain and clinically by fine movement deficits at the early stage, but the roles of α-Syn and associated neural circuits and neuromodulator bases in the development of fine movement deficits in PD are poorly understood, in part due to the lack of appropriate behavioral testing paradigms and PD models without motor confounding effects. Here, we coupled two unique behavioral paradigms with two PD models to reveal the following: (i) Focally injecting α-Syn fibrils into the dorsolateral striatum (DLS) and the transgenic expression of A53T-α-Syn in the dopaminergic neurons in the substantia nigra (SN, PITX3-IRES2-tTA/tetO-A53T mice) selectively impaired forelimb fine movements induced by the single-pellet reaching task. (ii) Injecting α-Syn fibers into the SN suppressed the coordination of cranial and forelimb fine movements induced by the sunflower seed opening test. (iii) Treatments with the adenosine A2A receptor (A2AR) antagonist KW6002 reversed the impairment of forelimb and cranial fine movements induced by α-Syn aggregates in the SN. These findings established a causal role of α-Syn in the SNc-DLS dopaminergic pathway in the development of forelimb and cranial fine movement deficits and suggest a novel therapeutic strategy to improve fine movements in PD by A2AR antagonists