Uniform and Multifunctional PEI-POSS/Carbon Encapsulation for High-Rate Performance and Surface Stabilization of Nickel-Rich Layered Cathodes in Lithium-Ion Batteries (Adv. Funct. Mater. 45/2023)

Graphene encapsulation is an attractive surface-coating technology that can simultaneously improve the rate capability and cycle stability of nickel-rich LiNi_xCo_yMn_1−x−yO₂ (NCM). Here, carbon encapsulation with the addition of polyethylenimine (PEI) and polyhedral oligomeric silsesquioxane (POSS), which can effectively suppress access to and generation of harmful factors in the electrolyte to maximize the rate performance and cycle stability of nickel-rich NCM, is described. The PEI-POSS/carbon layer not only facilitates electron and lithium-ion transport on the NCM surface but also inhibits side reactions with the electrolyte during repeated electrochemical reactions. In addition, it provides mechanical support that suppresses the formation of microcracks related to anisotropic volume change of nickel-rich NCM secondary particles and inhibits irreversible phase transitions on surface structures by mitigating electrolyte wettability. As a result, PEI-POSS/carbon-encapsulated NCM exhibits a higher rate capability (84 mAh g⁻¹ at 5 C) and cycle stability (93.5% for 100 cycles at 1 C) compared with bare NCM (0 mAh g⁻¹ at 5 C and 78.4% for 100 cycles at 1 C). In a cycle test at 45 °C, it achieves a capacity retention of 72.6% for 100 cycles at 1 C, which is a 323% improvement in performance over that of bare NCM (22.5%).     

POSS/PS纳米复合材料的制备与热性能

以CuCl/2,2'-联吡啶为催化剂,POSS-Cl为引发剂,采用ATRP法制备了POSS/PS纳米复合材料,用FT-IR、1H-NMR、XPS、XRD对产物进行了合成表征,并用DSC、TGA研究了复合材料的热性能.实验结果表明,ATRP法制备POSS/PS核壳型复合材料是可行的,POSS在PS中的分散性较好,POSS的加入对PS的Tg和Td有一定程度的提高.     

应力三轴度及轧辊凸度对93钨合金板材轧制损伤的影响

依据粉末烧结93钨合金板材轧制过程数值模拟模型,利用DEFORM有限元软件,分析了轧辊凸度对轧制钨板头部开裂的影响及开裂点处应力状态的变化情况。结果表明:随轧辊凸度数值的增加,轧制力和板材宽展呈上升趋势,等效应力和等效应变变化不明显;咬入阶段轧辊凸度绝对值增加使板材头部应力三轴度和开裂的趋势均增大,轧辊凸度取值范围应在-0.02~0.05mm。     

GPS高程拟合中多面函数及二次曲面函数的比较与分析

结合某区域的GPS和水准测量数据,用多面函数法、二次曲面函数法分别进行高程拟合,结果表明,在高程异常变化较大的区域用多面函数拟合GPS高程异常时,精度较高。     

板形控制技术在板带轧制过程中的应用

详细论述了板带钢轧制过程中常用的一些板形控制技术，包括WRB、HC、CVC、UPC、P(M、VC、UCM以及轧辊分段冷却控制技术等等，提出了现在板形控制的趋势是集多种控制方法于一体的综合板形控制技术。     

任意多边形顶点凸、凹性判别的简捷算法

给出了一种确定任意多边形顶点凸、凹性的简捷算法.该算法只需要2n+4次乘法,5n+10次加、减法及2n+3次比较即可完成(n是多边形顶点的个数).同时,给出了任意简单多边形走向的充要条件.     

道路设计中几种常见平曲线的设置与计算综述

平曲线设计在道路工程设计中是个重点，也是个难点，本文结合工程实例对几种常见平曲线的设置与计算方法作了归纳总结。     

Convex Translation Estimation

We compute all translations resulting in the union of two finite, convex sets being again convex. Convexity will be established by conditions on the outside of the convex hull. Computations are of low degree polynomial bounds on the worst case number of steps. This results in a set estimator for a mobile robot's translation value.