多源/多负荷直流微电网的能量管理和协调控制方法

低压直流微电网的能量管理与协调控制是保证其可靠运行需要解决的关键问题之一。基于直流母线电压信号的传统控制方法在不同工作模式将引起直流母线电压存在偏差,对恒功率负载造成不利影响,进而引起系统不稳定。针对这一问题,提出一种基于本地信息的能量管理和协调控制方法。详细分析并网运行、变流器限流运行以及孤岛运行模式下的能量管理、切换条件和协调控制方法。在系统孤岛运行模式下采用一种开环桨距角控制方法并结合恒压控制,消除直流电压波动,提高电能质量和系统稳定性。最后进行仿真研究,仿真结果验证了所提出方法的有效性。     

铜纤维烧结毡毛细芯结构毛细泵环的性能研究

毛细芯是毛细泵环的关键部件,其结构直接影响毛细泵环的传热性能.采用铜纤维烧结毡作为CPL的毛细芯,设计与制造了一种小型CPL及其性能测试系统,通过改变工质灌注量和毛细芯孔隙率实验研究对CPL传热性能的影响规律.结果表明:以乙醇为工质,在灌注量20mL条件下可使该CPL运行状态良好,工质灌注量过多或过少都会降低其传热性能;当烧结毡孔隙率在(70～95)%范围内时,CPL的系统热阻随孔隙率的增大先变小后变大,当孔隙率为80%时其系统热阻最小,该CPL传热性能达到最佳.     

Solution-Processed and Room-Temperature Spin Light-Emitting Diode Based on Quantum Dots/Chiral Metal-Organic Framework Heterostructure

Spin optoelectronics is an indispensable key for the future development of spintronics. In conventional spin light emitting diodes (LEDs), spin-polarized carrier pairs are injected electrically into the light emitting layer and create circularly polarized light (CPL). Generally, spin-polarized carriers are accomplished using ferromagnetic contacts or applying an external magnetic field, which will produce several drawbacks, including low temperature operation, low spin-polarized carriers injection efficiency, etc. To circumvent the existing shortcomings, here, an alternative approach is proposed and achieves spin-polarized LEDs at room temperature based on quantum dots (QDs)/chiral metal-organic framework heterojunction without using ferromagnetic contacts or magnetic fields. The spin-polarized injected layer composed of self-assembled monolayer (SAM)/Chiral-MOF ([Sr(9,10-adc)(DMAc)2]n)) film, which produces spin-polarized holes with spin orientation, determining the polarization and strength of circularly polarized electroluminescence (CP-EL). The spin-QLED emits CP-EL at a rate of 12.24% efficiency, which provides an excellent alternative to generate new functionality for conventional QLEDs. The approach is anticipated to be very useful, enabling to offer a general methodology for generating not yet realized spin optoelectronic devices.