利用改进布谷鸟优化算法的光伏全局MPPT方法

光伏阵列一般由大量组件构成,受环境影响易出现局部阴影,导致P-V曲线出现多峰现象。传统的最大功率点追踪(Maximum power point tracking,MPPT)控制策略如扰动观察法容易陷入局部最优, 从而降低光伏系统的发电效率。为了解决该问题, 本文提出了一种融合正弦余弦算法和自适应策略的布谷鸟优化算法(Cuckoo Search Algorithm Fusing Sine Cosine Algorithm And Adaptive Strategy ,AFCS),并将其应用于光伏全局MPPT控制中,用于改善MPPT过程中的收敛速度与追踪精度。最后设置多种光照情况并用花朵授粉算法和粒子群算法进行对比,经过MATLAB/Simulink仿真验证,该算法拥有较快的收敛速度和较高的追踪精度, 在各个光照条件下均能快速追踪到光伏阵列最大功率点, 可以有效提高光伏系统的发电效率。     

Recent progress in high-resolution tactile sensor array: From sensor fabrication to advanced applications

Tactile sensors can transform the environmental stimuli into electrical signals to perceive and quantify the environmental information, which show huge application prospects. The development of bionic robots and wearable devices towards intelligence has put high demands on the performance of tactile sensor arrays. Herein, the current state-of-the-art tactile sensor arrays over recent years have been summarized, from sensor array fabrication to advanced applications. The main preparation methods of patterned array including screen printing, 3D printing, laser microprocessing, and textile technology are discussed in detail. Strategies to optimize the signal crosstalk caused by flexible high-density sensor arrays are systematically introduced from the perspective of structure design and circuit design. Furthermore, advanced tactile sensors are not limited to a single pressure sensing function, and hence the development of multimodal detection for sensors has been discussed. In order to promote the adaptability in applications, stretchable and self-powered versatile integration scheme for advanced sensing are briefly described. Then, by means of machine learning and neural networks, it is possible to deeply explore the information embedded in the tactile acquisition signal with enriched application scenarios. Finally, the current challenges and the future perspectives for flexible tactile sensor arrays towards practical use are provided.     

Effective antibacterial and phase change PEG/Cu2O@A-HNTs composites for melt-spun difunctional PA6 fiber

Serving as the only defensive line between pathogens and human body, personal protective equipment (PPE) is increasingly attractive among researchers because of their strong antibacterial and temperature control abilities. However, efficient antibacterial properties and regenerative thermal control simultaneously remain unexplored in PPE. Here, one-dimensional halloysite nanotubes (HNTs) modified by acid etch method, are used to synthesis a multifunctional material of PEG/Cu₂O@A-HNTs via in-situ reduction and physical adsorption which serves the above two purposes. PEG/Cu₂O@A-HNTs showed rapid bacterial inactivation and achieved 96.3% bacteriostatic rate against E. coli in only 20 ?min. Meanwhile a broad and complete inactivation spectrum included both E. coli and S. aureus following a series of antibacterial mechanisms. Moreover, adsorption of 70 ?wt% PEG by acid etch HNTs is attributed to the nearly 3 times increased specific surface area compared with native HNTs. This enabled PEG/Cu₂O@A-HNTs to attain a phase change enthalpy of 108.4 ?J/g. In addition, using PEG/Cu₂O@A-HNTs as additives, antibacterial and phase change fiber (APCF) were melt-spun. Their efficiency factor against E. coli and S. aureus was above 99.99%, and retained a temperature control ability for 180s and 272s compared with PA6 fiber in hot and frigid environments respectively.