Cycling performance of layered oxide cathode materials for sodium-ion batteries

Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.

15 nm Bulk nFinFET器件性能研究及参数优化

为研究Bulk FinFET工作时基本结构参数、器件温度和栅极材料对其性能的影响,建立了一个15 nm n型Bulk FinFET器件模型,仿真分析了不同栅长、鳍宽、鳍高、沟道掺杂浓度、器件工作温度、栅极材料对器件性能的影响,发现增长栅长、降低鳍宽和增加鳍高有助于抑制短沟道效应;1×10^(17)cm^(-3)以下的低沟道掺杂浓度对器件特性影响不大,但高掺杂会使器件失效;器件工作温度的升高会导致器件性能的下降;采用高K介质材料作为栅极器件性能优于传统材料SiO_(2)。

Fabrication of ultrafine-grained AA1060 sheets via accumulative roll bonding with subsequent cryorolling

Ultrafine-grained(UFG)AA1060 sheets were fabricated via five-cycle accumulative roll bonding(ARB)and subsequent three-pass cold rolling(298 K),or cryorolling(83 K and 173 K).Microstructures of the aluminum samples were examined via transmission electron microscopy,and their mechanical properties were measured via tensile and microhardness testing.Results indicate that ultrafine grains in ARB-processed sheets were further refined by subsequent rolling,and the grain size became finer with reducing rolling temperature.The mean grain size of 666 nm in the sheets subjected to ARB was refined to 346 or 266 nm,respectively,via subsequent cold rolling or cryorolling(83 K).Subsequent cryorolling resulted in ultrafine-grained sheets of higher strength and ductility than those of the sheets subjected to cold rolling.

Superplastic behavior of friction-stir welded Al-Mg-Sc-Zr alloy in ultrafine-grained condition

The present work was undertaken to improve superplastic ductility of friction-stir welded joints of ultrafine-grained(UFG)Al-Mg-Sc-Zr alloy.In order to suppress the undesirable abnormal grain growth,which typically occurs in the heavily deformed base material,the UFG material was produced at elevated temperature.It was suggested that the new processing route could reduce dislocation density in the UFG structure and thus enhance its thermal stability.It was found,however,that the new approach resulted in a relatively high fraction of low-angle boundaries which,in turn,retarded grain-boundary sliding during subsequent superplastic tests.Therefore,despite the successful inhibition of the abnormal grain growth in the base-material zone,the superplastic deformation was still preferentially concentrated in the fully-recrystallized stir zone of the material.As a result,the maximal elongation-to-failure did not exceed 700%.

Unreacted equation of states of typical energetic materials under static compression:A review

The unreacted equation of state（EOS） of energetic materials is an important thermodynamic relationship to characterize their high pressure behaviors and has practical importance. The previous experimental and theoretical works on the equation of state of several energetic materials including nitromethane, 1,3,5-trinitrohexahydro-1,3,5-triazine（RDX）,1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）, hexanitrostilbene（HNS）, hexanitrohexaazaisowurtzitane（HNIW or CL-20）, pentaerythritol tetranitrate（PETN）, 2,6-diamino-3,5-dinitropyrazine-1-oxide（LLM-105）, triamino-trinitrobenzene（TATB）, 1,1-diamino-2,2-dinitroethene（DADNE or FOX-7）, and trinitrotoluene（TNT） are reviewed in this paper. The EOS determined from hydrostatic and non-hydrostatic compressions are discussed and compared. The theoretical results based on ab initio calculations are summarized and compared with the experimental data.

Investigation on Rapidly Solidified T15 High Speed Steel Powder and Its Bulk Microcrystalline Material

Authors produced rapidly solidified T15 high speed steel powders by high pressure(5~ 6MPa) N_a atomization and liquid N_2 cooling,observed and analyzed the morphology and structure of the powders;at the same time,prepared bulk microcrystalline T15 high speed steel materials by hot extruding or HIPing and hot rolling of the powders,observed and measured the microstructure and performance of the bulk materials.It was shown that rapid solidification may change the solidification characteristics and structure of T15 high speed steel powder and improve the qualities and properties of T15 high speed steel materials.

Ionic Conductivity of Nano-LaF_3 Bulk Material at Room Temperature

Nanocrystalline powder of LaF3 was synthesized by a method of direct precipitation from water solution. Particle size and shape of LaF3 nanocrystalline powder was analysed with TEM. Particles were mainly spherical with narrow particle size distribution （10 20 nm）. The average particle size analysed with XRD is 16.7 nm. Nano-LaF3 bulk material was prepared by compacting the powder to 1 GPa at room temperature and a vacuum of 10^-4 Pa. The ionic conductivity of nano-LaF3 bulk material was studied with complex impedance spectra at room temperature. The ionic conductivity of nano-LaF3 bulk material （1 × 10^-5 S·cm^-1 ） at room temperature is significantly increased compared to that of single crystal LaF3 （1 × 10^-6 S·cm^-1）. A special phenomenon was observed firstly time that the ionic conductivity increased gradually with multiple testing in result of relaxation.

THE SELF-GRINDING MECHANISM AND AFFECTING FACTORS OF BULK MATERIAL IN FLUID MOTION

The fluidity and classification of bulk material (loose body) were introduced, the self-grinding mechanism and the affecting factors of bulk materials in various forms of phase, state and motion were investigated. A rotational-flow-state centrifugal autogenous grinder was developed on the basis of applying self-grinding mechanism of bulk material,the result tested by the autogenous grinder was compared with that tested by 4R Raymond mills, and fine particles with extremely high specific area were obtained. The feasibility of the developed new-type autogenous grinder in the view of fluid motion of bulk material was proved.

EXPERIMENTAL STUDY ON ULTRAFINE COMMINUTION IN THEORY OF VERTIGINOUS CURRENT OF BULK MATERIAL

Experiment about ultrafine comminution in theory of vertiginous current of bulk material has successfully performed by a lately developed vertical shaft centrifugal autogenous grinder. The results of tested several materials are analyzed, moreover. the comminution mechanism and the affecting factors of ultrafine comminution are analyzed.

Effect of Pyrophyllite Addition on Properties of Lightweight Insulation Refractory Materials

To solve the problem of over-high density of lightweight insulation refractory bricks prepared with fly ash, new lightweight insulation refractory materials with density 〈 0. 89 g · cm^-3 were .synthesized using pyrophyl-lite, .fly ash, and Suzhou clay as the main starting materials and saw dast as the pore forming substance, and controlling the addition of the pyrophyllite （20%, 30% , and 40% by mass ） and the treating temperature （1 250, 1 300, 1 350, and 1 400 ℃ ）. The synthesized materials were characterized by the XRD, SEM and the thermal conductivity measuring in.strument. The results show at pyrophyllite addition of 30% and treat temperature of l 400 ℃ , the material can achieve linear shrinkage of 6. 6%, apparent porosity of 57%, bulk density of 0. 75 g · cm^-3, compressive strength of 2.7 MPa, and thermal conductivity at 350 ℃ of 0. 152 -0. 216 W·（ m·K）^-1.This indicates that the pyrophyllite decomposition at high temperatures forms mullite and amorphous quartz introducing volume expansion, which counteracts some shrinkage at high temperatures. So it is feasible to use pyrophyllite, fly ash waste and clay to prepare lightweight insulation refractory materials.

Synthesis and room temperature ionic conductivity of nano-LaF_3 bulk material

The ionic conductivity (at room temperature) of nano-LaF3 bulk material and a new discovered phenomenon of increasing ionic conductivity caused by grain boundary relaxation activated by AC (alternating current) shocking were reported. Nano-crystalline powder of LaF3 with average grain size of 16.7 nm was synthesized with a method of direct precipitation from aqueous solution. Particle size and shape of LaF3 nano-crystalline powder were analyzed by XRD and TEM. Nano-LaF3 bulk material was prepared by compacting the powder to 1 GPa at room temperature and vacuum of 10?4 Pa. The ionic conductivity of nano-LaF3 bulk material was studied with complex impedance spectra at room temperature. The ionic conductivity of nano-LaF3 bulk material (10?5 S/cm) at room temperature is significantly increased compared with that of single crystal LaF3 (10?6 S/cm). A special phenomenon is observed for the first time that the ionic conductivity increases gradually with AC scanning times.

基于数字孪生的矿山散料堆场堆取料机智能监测系统

在许多涉及散料装卸作业的大型储料场中,斗轮堆取料机被视为当前最为理想的大型可连续作业机械,为了延长其使用寿命,降低维修成本并解决人工巡检不便的问题,提出了一种基于五维数字孪生的智能健康监测系统。通过机身外部布设光纤光栅传感器以及内置电机实时运转数据获取堆取料机的当前工作状态,并将数据传入内部信息交互通信网络进行数据的分离存储与融合处理,在消除双光栅由于机械疲劳所带来的温度补偿误差后,构建了多数据融合的、立体化的堆取料机数字健康模型,实现了堆取料机健康状态的智能化预测与立体化监测。通过在秦皇岛港散料矿物储料场的QL6000.55型斗轮堆取料机进行全系统的安装运行,极大促进了料场数字化进程,改变了管理模式,提高了生产效率,直接增加了经济效益。研究表明:该系统能够可靠地提供斗轮取料机的实时工作状态,对基本的故障类型有着一定的预警效果,降低了堆取料机维护的人力与物力投入,为矿区大型机械健康监测提供了有益参考。

基于GA-WNN的散装物料装车智能控制系统研究

为了解决散装物料在装车过程中所出现的偏载、欠载及控制精度低等问题,提出了一种基于GA-WNN的散装物料装车智能控制系统。首先对列车行驶智能控制总体设计方面进行了详细说明,阐述了各功能模块的运行机理;其次对小波神经网络(WNN)控制器的模型结构进行了描述,解析了各个结构层的处理机制,并结合遗传算法(GA)对WNN控制器进行优化,使其输出理想的装车控制效果。实验结果表明,该系统有效解决了物料装载过程中所出现的欠载和偏载现象,大大提高了装车的效率和精准度,为工矿企业的高效安全生产提供了有力保障。

固废基水化硅酸钙制备及综合利用研究进展

大宗固废是工业生产过程中产生的各种固体废弃物,大多数固废中含有较多的硅资源和各种有价资源。水化硅酸钙(C-S-H)是一种疏松多孔、表面活性强的材料,被广泛应用于水泥活化、保温材料制备和重金属吸附等方面,将大宗固废有价资源高效提取和硅资源高效利用制备C-S-H相结合,是提高固废资源化和实现C-S-H材料规模化利用的良好途径。因此,本文分析了固废基C-S-H的合成方法及其结构、性能特点,论述了C-S-H材料在建材、环境、化工、生物等领域的应用,并进一步展望了其未来的发展方向,从而为大宗固废的硅资源利用和C-S-H材料的可控制备提供参考。

散料集装箱快速定量装车技术研究与应用

在我国经济发展处于新常态和“一带一路”倡议推广的背景下,单车双集装箱散料物流运输需求加速提升,传统装车技术无法实现单车双集装箱散料的连续装载。针对上述问题,分析了煤炭集装箱快速定量装车典型工艺参数,研究了单套、两套独立、两套联体、单套双仓快速定量装车可行方案,提出一种双仓协同异步装车新技术,称重仓、溜槽相互独立作业,解决了单车双集装箱无法连续装车的难题,装车效率大大提高,装车质量也得到保障。工程应用表明,散料集装箱快速定量装车系统最大装车能力可达7200 t/h,较实际装载需求提升10%以上,实现了单车双集装箱的连续、快速、高效装载。

四川九绵高速平武段物源量对泥石流流体性质与致灾强度影响的差异性分析

九绵高速公路LJ9段沟谷型泥石流灾害频发,时常对附近村落和基础设施造成威胁。为了避免灾害对区域高速公路和G247国道的二次冲击,对九绵高速LJ9段沿线存在泥石流暴发痕迹的6条泥石流沟的物源特征与规模进行研究,认为该地区泥石流属于低频沟谷暴雨型。泥石流容重值在1.647~1.843 g/cm^(3),流速为3.45~6.54 m/s,流量为29.47~253.45 m^(3)/s,一次过流总量为0.99×10^(4)~8.28×10^(4)m^(3)。文章通过对比九绵高速“8•16”泥石流规模特征差异,分析物源量与泥石流的容重、规模的关系,建立了相关性公式。研究结果发现:(1)研究区泥石流属于低频沟谷暴雨型,流体性质与沟道物源量紧密相关,单位面积物源量与泥石流容重呈线性关系;单位面积物源量大于1.65×105 m^(3)/km^(2)和小于1.13×105 m^(3)/km^(2)时,泥石流分别表现为黏性和稀性。(2)在相同地质条件下,泥石流物源量与规模之间呈线性相关,泥石流一次总量随流域单位面积物源量减小而减小。(3)泥石流致灾能力受物源量控制,物源总量超过80×10^(4)m^(3)的沟道易形成黏性泥石流,沟口的堆积扇更大,对应破坏力更强;物源总量小于80×10^(4)m^(3)的沟道更易形成稀性泥石流,冲出沟口的破坏性明显小于黏性泥石流,对沟口的人员与工程建设的威胁更小。该研究结果可为九绵高速公路的规划设计与建设提供一定参考,也为山区基础设施的安全运营、灾害防御工程建设工作提供科学依据。

压电式超声雾化降尘系统设计及其试验研究

通过传送带传送物料是散料工业运输的主要方式,对运输过程中产生的粉尘进行治理是散料工业运输亟需解决的问题,目前应用比较多的方法为雾化降尘法。为了提升雾化降尘的效果,设计了一种30 kHz喇叭型压电式超声雾化装置和配套的雾化降尘试验系统,并采用单因素试验研究入口水流量、风速、粉尘种类、颗粒直径、喷嘴安装角度等工艺参数对雾化降尘效率的影响规律。结果表明,当入口水流量为30 L/h时,对煤粉粉尘降尘效率为75.9%;当风速为2.1 m/s时,对煤粉粉尘降尘效率为61.1%;相比较于煤粉和沙子,黄土的降尘效率略高;该喷嘴对粒径为107~180μm范围内的煤粉粉尘降尘效率最高为73.9%;当喷嘴安装角度为0时,对煤粉粉尘降尘效率最高为81%。

北冰洋欧亚大陆边缘表层沉积物全岩轻矿物组成及其环境指示意义

北冰洋欧亚大陆边缘是海冰的主要生成区域,由洋流、海冰和冰山输送的陆源碎屑沉积物是北冰洋沉积物的主要组成部分,沉积物中矿物组成是揭示北冰洋物质来源、洋流模式的重要资料。本文基于前人应用X射线衍射法研究的441个北冰洋欧亚大陆边缘全岩轻矿物组成资料,探索研究区全岩轻矿物来源及搬运分选模式。研究结果表明:(1)北冰洋欧亚大陆边缘的轻矿物以石英和长石为主,石英具有多个特征源区并广泛分布于研究区各处;(2)长石族主要包括斜长石和钾长石,表征了典型的火山物质输入,是发育火成岩省和火山带的欧亚北极大陆特征矿物。斜长石通常由北极河流输送入海,并通过海冰搬运到更远的地区,因此其分布与穿极流的路径极其相似;(3)钾长石对应冰山搬运的粗颗粒物质,其高值分布在欧亚大陆边缘,与斜长石的解耦表明了其对区分不同的火山来源物质具有一定的意义;(4)白云石通常来自于北美源区,方解石来源则更复杂,可能包含了自生来源。以上研究结果有助于更全面理解北冰洋沉积物源-汇过程,为厘清北冰洋欧亚大陆边缘沉积环境变化提供重要参考。

高性能有机太阳能电池宽带隙聚合物给体材料研究进展

随着光伏材料的不断革新,有机光伏(OPV)电池的能量转换效率(PCE)已经接近20%,聚合物给体材料与小分子电子受体材料的开发被认为是提升OPV电池PCE的核心。在众多给体材料中,宽带隙聚合物给体材料因出色的光电特性已占据OPV给体材料的主导地位。为了进一步提高OPV的光伏效率,总结并梳理宽带隙聚合物给体材料的分子结构与其光电特性的关联是必要的。首先,本文总结了聚合物给体材料的光学带隙和分子能级的调控方法;其次,探讨并总结了聚合物溶液聚集效应的调控方法以及与光活性层形貌的关联;再次,强调了降低OPV电池的能量损耗重要性,并讨论了降低其能量损耗的方法;再次,针对当前优秀的宽带隙聚合物给体进行总结;最后,讨论了基于宽带隙聚合物给体的非富勒烯OPV电池商业化实现的机遇和挑战。

川滇干热河谷区土壤容重空间变异特征--以滇中楚雄地区为例

土壤容重是土壤最重要的物理性质之一,是植被恢复、生态修复和估算土壤有机碳储量的重要参数。滇中楚雄州北部特殊的地理位置和独特的地形地貌特征组合形成了典型的干热河谷气候和非干热河谷气候,为探讨土壤容重变化影响因素提供了极好的自然条件。通过系统实测土壤容重,采用统计学方法拟合容重传递函数,探讨了研究区内土壤容重特征和空间分布规律。结果显示:研究区干热河谷区土壤容重高,果园对土壤容重影响深度最大,燥红土容重最高,容重传递函数中有机碳贡献最大。研究结果可为干热河谷区生态保护修复、土壤碳储量估算提供基础数据和理论支撑。