Synthesis and electrochemical properties of Al-doped LiVPO4F cathode materials for lithium-ion batteries

Al-doped LiVPO4F cathode materials LiAlxV1-xPO4F were prepared by two-step reactions based on a car-bothermal reduction （CTR） process. The properties of the Al-doped LiVPO4F were investigated by X-ray diffraction （XRD）,scanning electron microscopy （SEM）,and electrochemical measurements. XRD studies show that the Al-doped LiVPO4F has the same triclinic structure （space group p-↑1 ） as the undoped LiVPO4F. The SEM images exhibit that the particle size of Al-doped LiVPO4F is smaller than that of the undoped LiVPO4F and that the smallest particle size is only about 1 μm. The Al-doped LiVPO4F was evaluated as a cathode material for secondary lithium batteries,and exhibited an improved reversibility and cycleability,which may be attributed to the addition of Al^3＋ ion by stabilizing the triclinic structure.     

烟气成分对湿式电除尘器电晕放电特性的影响

建立单通道线板式湿式电除尘器机理实验台,考察烟气中主要成分(O₂、H₂O和粉尘)对湿式静电除尘器放电特性的影响。随着烟气成分(O₂、H₂O和粉尘)浓度的增加,空间静电场中负电荷密度增加,电场分布均匀性提高,抑制电晕放电,电晕电流降低;随着电压升高,烟气成分对电晕放电的抑制作用减弱。其中,烟气中O₂的体积分数增加引起电晕电流下降的速率不为常数,O₂体积分数小于6%时,下降速率明显减小。烟气中液相水滴附着在电晕线表面引起表面电场畸化,起晕电压降低,击穿电压提高,湿式静电除尘器的工作电压窗口增大。电晕电流与烟气中粉尘浓度呈线性相关关系,粉尘粒径越小对电晕放电的抑制作用越明显。     

基于有限元方法的CeCl3和NdCl3在LiCl-KCl熔盐中的电极动力学模拟

充分理解锕系元素和镧系元素在熔盐中的行为和性质是实现反应堆乏燃料熔盐电解后处理的关键,然而熔盐电解实验所需的高温环境、腐蚀性熔盐甚至放射性物质等条件限制了实验的广泛开展。为寻求一种低成本且可靠的获取元素在熔盐中性质的途径,采用有限元方法在不同温度下模拟了不同浓度的三氯化铈和三氯化钕在LiCl-KCl熔盐中的循环伏安曲线,并与实验数据做了对比。结果表明,有限元方法能够较为准确地反映实际电化学过程,继而为乏燃料熔盐电解后处理提供数据支持。     

Cyclic Nigerosyl-Nigerose as Oxygen Nanocarrier to Protect Cellular Models from Hypoxia/Reoxygenation Injury: Implications from an In Vitro Model

Heart failure (HF) prevalence is increasing among the aging population, and the mortality rate remains unacceptably high despite improvements in therapy. Myocardial ischemia (MI) and, consequently, ischemia/reperfusion injury (IRI), are frequently the basis of HF development. Therefore, cardioprotective strategies to limit IRI are mandatory. Nanocarriers have been proposed as alternative therapy for cardiovascular disease. Controlled reoxygenation may be a promising strategy. Novel nanocarriers, such as cyclic nigerosyl-nigerose (CNN), can be innovative tools for oxygen delivery in a controlled manner. In this study we analyzed new CNN-based formulations as oxygen nanocarriers (O₂-CNN), and compared them with nitrogen CNN (N₂-CNN). These different CNN-based formulations were tested using two cellular models, namely, cardiomyoblasts (H9c2), and endothelial (HMEC) cell lines, at different concentrations. The effects on the growth curve during normoxia (21% O₂, 5% CO₂ and 74% N₂) and their protective effects during hypoxia (1% O₂, 5% CO₂ and 94% N₂) and reoxygenation (21% O₂, 5% CO₂ and 74% N₂) were studied. Neither O₂-CNN nor N₂-CNN has any effect on the growth curve during normoxia. However, O₂-CNN applied before hypoxia induces a 15–30% reduction in cell mortality after hypoxia/re-oxygenation when compared to N₂-CNN. O₂-CNN showed a marked efficacy in controlled oxygenation, which suggests an interesting potential for the future medical application of soluble nanocarrier systems for MI treatment.     

采用循环伏安法研究微孔型多孔炭电极的电容特性

以酚醛树脂为原料,KOH为活化剂,制备出3种不同孔径分布的微孔型多孔炭(孔径≤2 nm)。在低温氮气吸附法测定BET比表面积和孔结构的基础上,采用循环伏安法考察了这3种微孔型多孔炭作电极的双电层电容器(EDLC)的电容特性。实验结果表明,微孔型多孔炭作电极的EDLC的电容特性是:在低扫描速率下,其循环伏安曲线达到电容平台后在高电压(±1.0 V)附近出现峰电容;延长在电解液中的浸渍时间,电极的比电容增大,高电位附近的峰电容减小。3种不同孔径分布的微孔型多孔炭作电极的EDLC的循环伏安特性受浸渍时间影响的程度也不同。     

34CrMoA转子钢高温循环蠕变断口分形维数与蠕变性能的关系

用垂直剖面法测定了34CrMoA转子钢在550℃循环蠕变断口的分形维数,分析、比较了分形维数与蠕变性能的关系,结果表明,分形维数与断裂应变呈线性关系。     

THE INFLUENCE OF ENVIRONMENT ON FATIGUE AND FRACTURE OF IRON ALUMINIDES

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The role of thermal shock in cyclic oxidation

The effect of thermal shock on the spalling of oxides from the surfaces of several commercial alloys was determined. The average cooling rate was varied from approximately 240°C/sec to less than 1.0°C/sec during cyclic oxidation tests in air. The tests consisted of 100 cycles of 1 hr at the maximimum temperature (1100 or 1200°C). The alloys were HOS-875, TD-Ni, TD-NiCrAl, In-601, In-702, and B-1900 plus Hf. All of these alloys exhibited partial spalling within the oxide rather than total oxide loss down to bare metal. Thermal shock resulted in deformation of the metal, which in turn resulted, in most cases, in change of the oxide failure mode from compressive to tensile. Tensile failures were characterized by cracking of the oxide and little loss, while compressive failures were characterized by explosive loss of platelets of oxide. This behavior was confirmed by examination of mechanically stressed oxide scales. The thermally shocked oxides spalled less than the slow-cooled samples with the exception of TD-NiCrAl. This material failed in a brittle manner rather than by plastic deformation. The HOS-875 and the TD-Ni did not spall during either type of cooling. Thus, the effect of thermal shock on spalling is determined, in large part, by the mechanical properties of the metal.     

提高杂质泵过流部件品质的工艺技术

从杂质泵过流部件的需求现状和失效分析、材质和化学成分选用时的量化指数 ,介绍了护套、后护板、前护板 ,叶轮等铸造工艺 ,热处理工艺要点 ,提出了提高杂质泵过流部件品质的闭环系统。     

6005合金型材代替6063合金型材用于建筑幕墙

根据6005铝合金工业型材的生产经验，对6005和6063铝合金型材的合金成分、力学性能、时效制度、尺寸保证进行分析对比，确定6005铝合金型材代替6063铝合金型材应用于建筑幕墙领域的可行性。