Liquid phase exfoliation of indium selenide: Achieving the optimum exfoliating parameters and unraveling the mechanism

The two-dimensional (2D) van der Waals indium selenide (InSe) exhibits the ultra-low intralayer Young's modulus yet the high interlayer cleavage and slipping energy, which could thus be obtained by the liquid phase exfoliation (LPE) method. Here, we designed 48 experiments to systematically achieve its optimum LPE parameters including the exfoliating solvent of N-Methyl-2-pyrrolidinone (NMP), ultrasonic power of 180 ?W, ultrasonic time of 12 ?h and exfoliating concentration of 6.25 ?mg/mL. The resulting optimal 2D InSe nanosheets show a uniform lateral size distribution of about 200 ?nm without impurities. We further analyzed the underlying exfoliating mechanism through the scanning electron microscopy (SEM) investigations. The results show that NMP has the more suitable Hansen solubility parameters to disperse and stabilize the 2D nanosheets. Increasing the ultrasonic power and time can provide plenty of energy to destroy the van der waals' force that exist between the interlayers of InSe and induce intralayer fragmentation. This work would provide a significant guideline for selecting exfoliating parameters to obtain the expected InSe nanosheets and thus extend its applications in optical sensors and nanocomposites.     

独立微网电能市场区间报价报量交互式交易优化

针对大规模分布式参与者如何在有限交易水平下，自由灵活参与微网电能市场交易的问题，提出建立上、下层分布式交易的微网市场优化模型.其中，上层为参与者效能最大化，下层为微网社会经济效益最大化，并采用交替方向乘子法分层交互迭代求解.实例分析结果表明，所提出的模型可充分协调优化参与者效能和市场社会经济效益，提高微网可再生能源消纳、参与者效能和社会福利.     

机泵系统流量调节方案的优化设计

本文旨在对任一机泵系统流量调节的各种方案进行优化设计,为此建立了以投资回收期为目标函数、满足流量分布等为约束条件的数学模型。同时通过对单台、并联机泵系统各种调节方案的节能计算公式的推导,最终得出目标函数的最优解。