基于DEPSO-RBFNN的变压器表面温度预测模型

提出一种基于差异进化算法(DE)和粒子群优化算法(PSO)的新型混合进化算法DEPSO,以及基于DEPSO的径向基函数神经网络(RBFNN)模型,并应用于预测SF6气体绝缘变压器表面温度.该模型用DEPSO算法训练RBFNN隐层中心的数量和位置,并采用递推最小二乘法确定网络输出层的权值.对某变电站SF6气体绝缘变压器的表面温度预测结果表明:与BP网络、基于进化规划(EP)、PSO的RBFNN相比,这种建模方法具有更高的预测精度.     

基于大数据的电力客户行为分析体系研究及实践

随着我国电力市场的发展,供电企业紧跟数字化发展步伐加快信息系统建设,各业务系统在运行过程中积累了海量信息数据资源,利用这些数据资源进行数字化分析已经渐渐成为供电企业的重点工作。在供电企业不断地拓展分析范围,优化分析方法的过程中,大量的数据资产被盘活,巨大企业价值与社会价值逐渐显现。大数据技术的使用可体现在电力系统运行的各种环节,为电力信息的商业化利用提供有力支撑。基于大数据技术的电力客户用电行为分析能提高电力系统的运行效率,为供电企业的实际运行提供决策依据。文章分析了国内、外电力行业大数据应用的进程及现状,根据不同类型客户的用电行为建立了基于大数据技术电力客户行为分析体系,对大数据技术的实践情况进行探究,实现电力客户用电行为的深度分析,为客户提供更优质的服务体验。     

离散时间系统变结构控制基于衰减控制的趋近律

讨论了利用离散趋近律设计离散时间系统的变结构控制问题, 在衰减控制的基础上, 提出了衰减变速趋近律和衰减幂次趋近律. 理论分析和仿真结果表明, 本文所提的方法是有效的, 既保证了闭环系统的渐进稳定性, 又大大减少了系统的抖动现象.     

Constructing stable “bridge” structures with compatibilizer POE-g-GMA to improve the compatibility of starch-based composites

With the development of degradation technologies such as chemical-catalysis and bio-catalysis, starch-polyethylene (PE) composites have been revitalized as industrial packaging materials. However, starch and PE suffer from interfacial incompatibility. In this study, poly(octene ethylene) grafted glycidyl methacrylate (POE-g-GMA) was added at relatively low amounts (0–7 wt%) to construct robust structures between thermoplastic starch (TPS) and low-density polyethylene (LDPE). Tensile strength increased by 36.39% with the addition of 1 wt% POE-g-GMA. Meanwhile, a smooth surface was observed by SEM, and a fibrillar cross-linked structure appeared on the fractural surface of the blend. POE-g-GMA formed a stable “bridge” at the interface between TPS and LDPE, which increased the thermal stability of the blend as well. The crystallinity of LDPE increased from 20.5% (without addition) to 32.8% (with 1 wt% addition), whereas the average crystallite size decreased slightly. The optimal POE-g-GMA content was found to be 1 wt% based on mechanical and thermal measurements. The results of this study can provide a reference for improving the interfacial compatibility of biopolymers and fossil-fuel-based polymers.     

Single-Ion Polymer Electrolyte Based on Lithium-Rich Imidazole Anionic Porous Aromatic Framework for High Performance Lithium-Ion Batteries

The low ionic conductivity and Li⁺ transference number ($t_{L{i}^{+}}$) of solid polymer electrolytes (SPEs) seriously hinder their application in lithium-ion batteries (LIBs). In this study, a novel single-ion lithium-rich imidazole anionic porous aromatic framework (PAF-220-Li) is designed. The abundant pores in PAF-220-Li are conducive to the Li⁺ transfer. Imidazole anion has low binding force with Li⁺. The conjugation of imidazole and benzene ring can further reduce the binding energy between Li⁺ and anions. Thus, only Li⁺ moved freely in the SPEs, remarkably reducing the concentration polarization and inhibiting lithium dendrite growth. PAF-220-quasi-solid polymer electrolyte (PAF-220-QSPE) is prepared through solution casting of Bis(trifluoromethane)sulfonimide lithium (LiTFSI) infused PAF-220-Li and Poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP), and possessed excellent electrochemical performance. The electrochemical property are further improved by preparing all-solid polymer electrolyte (PAF-220-ASPE) via pressing-disc method, which has a high Li⁺ conductivity of 0.501 mS cm⁻¹ and $t_{L{i}^{+}}$ of 0.93. The discharge specific capacity at 0.2 C of Li//PAF-220-ASPE//LFP reached 164 mAh g⁻¹, and the capacity retention rate is 90% after 180 cycles. This study provided a promising strategy for SPE with single-ion PAFs to achieve high-performance solid-state LIBs.     

Recent Progress of Conductive Hydrogel Fibers for Flexible Electronics: Fabrications,Applications, and Perspectives

Flexible conductive materials with intrinsic structural characteristics are currently in the spotlight of both fundamental science and advanced technological applications due to their functional preponderances such as the remarkable conductivity, excellent mechanical properties, and tunable physical and chemical properties, and so on. Typically, conductive hydrogel fibers (CHFs) are promising candidates owing to their unique characteristics including light weight, high length-to-diameter ratio, high deformability, and so on. Herein, a comprehensive overview of the cutting-edge advances the CHFs involving the architectural features, function characteristics, fabrication strategies, applications, and perspectives in flexible electronics are provided. The fundamental design principles and fabrication strategies are systematically introduced including the discontinuous fabrication (the capillary polymerization and the draw spinning) and the continuous fabrication (the wet spinning, the microfluidic spinning, 3D printing, and the electrospinning). In addition, their potential applications are crucially emphasized such as flexible energy harvesting devices, flexible energy storage devices, flexible smart sensors, and flexible biomedical electronics. This review concludes with a perspective on the challenges and opportunities of such attractive CHFs, allowing for better understanding of the fundamentals and the development of advanced conductive hydrogel materials.