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81.
Yu Zhang Qian Zhou Jixin Zhu Qingyu Yan Shi Xue Dou Wenping Sun 《Advanced functional materials》2017,27(35)
Energy storage and conversion technologies are vital to the efficient utilization of sustainable renewable energy sources. Rechargeable lithium‐ion batteries (LIBs) and the emerging sodium‐ion batteries (SIBs) are considered as two of the most promising energy storage devices, and electrocatalysis processes play critical roles in energy conversion techniques that achieve mutual transformation between renewable electricity and chemical energies. It has been demonstrated that nanostructured metal chalcogenides including metal sulfides and metal selenides show great potential for efficient energy storage and conversion due to their unique physicochemical properties. In this feature article, the recent research progress on nanostructured metal sulfides and metal selenides for application in SIBs/LIBs and hydrogen/oxygen electrocatalysis (hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction) is summarized and discussed. The corresponding electrochemical mechanisms, critical issues, and effective strategies towards performance improvement are presented. Finally, the remaining challenges and perspectives for the future development of metal chalcogenides in the energy research field are proposed. 相似文献
82.
Qian Wu Ghislain L.P. Elings V.B. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2000,88(9):1491-1498
Solid immersion microscopy, similar to liquid immersion microscopy, extends the diffraction limit by filling the object space with a high refractive index material, such as glass (index of refraction n=1.5-2), sapphire (n/spl sim/1.8), and semiconductor materials (n/spl sim/3), which shrink the wavelength of light. But solid immersion technique can achieve significantly higher spatial resolution since the refractive indices of available solids can be much higher than those of liquids (n=1.3-1.5). Besides high spatial resolution, solid immersion microscopy also possesses all the good properties of far-field imaging, such as high transmission efficiency and parallel imaging capability, which make it outstanding among beyond-the-diffraction-limit optical imaging techniques. In this paper, we discuss, from an experimental point of view, the resolution limit of solid immersion microscopy and the implementation of such technique in various applications. 相似文献
83.
采用ZnPc作为ZnPc/C60有机太阳电池阴极修饰层,分析了其对器件光电性能和稳定性的影响.研究了不同厚度ZnPc修饰层对器件性能的影响,结果表明用3 nm ZnPe修饰的器件性能最好.通过传输矩阵的方法画出了结构为ITO/ZnPc(30 nm)/C60(40 nm)/ZnPc(3 nm)/Al(100 nm)电池内部两束敏感光线(630 nm和450 nm光波)的光强分布图,加入3 nm ZnPc对光强分布影响不大.实验还对比分析了未添加、添加LiF和ZnPc修饰层器件的稳定性,用ZnPc修饰的器件更好地改善了稳定性,并对相关机理进行了讨论. 相似文献
84.
电推进技术是航天推进技术一个重要的发展方向.针对新一代通信卫星平台电推进系统的需求,对用于电推进系统的电源处理单元的4种备选配置方案做了介绍,并对每种方案的可靠性进行了计算.通过可靠性指标对比和对配置方案的分析,为方案优选提供了一些依据. 相似文献
85.
红外焦平面阵列非均匀性自适应校正算法研究 总被引:11,自引:2,他引:11
在分析红外焦平面阵列非均匀性校正现行算法的基础上,提出了一种具有自适应性能的新算法。该算法以小波变换中的滤波器理论为基础,通过将图像序列在时间域的尺度分解和相庆统计量计算,获得在红外焦平面校正中起影响的偏置和增益系数。模拟实验结果验证了其有效性和先进性。 相似文献
86.
87.
Hydrogels, a class of materials with a 3D network structure, are widely used in various fields especially in biomedicine. Injectable hydrogels could facilitate the encapsulation and controlled release of small molecular drugs, macromolecular therapeutics, and even cells. With the rapid development of cancer immunotherapy, such injectable hydrogels have attracted wide attention for local immunomodulation to boost systemic anticancer immune responses, realizing more effective immunotherapy at lower doses. The latest progresses in the development of various smart injectable hydrogels for cancer immunotherapy are summarized here. Although applied locally, such injectable hydrogels can activate systemic antitumor immune responses, safely and effectively inhibiting the tumor metastasis and recurrence. Moreover, it is discussed how injectable hydrogel‐based cancer immunotherapy would contribute to the development of next generation of cancer treatment together with their potential for clinical translation. 相似文献
88.
在皮肤症状计算机辅助测试系统研究中,症状特征的筛选是提高系统诊断的关键问题,针对这个问题提出基于遗传算法和LVQ神经网络相结合的包裹算法。同时为了提高搜索效率,采用改进的自适应遗传算法。并用留一交叉法验证LVQ神经网络分类器的识别率.对初步提取的体现病态皮肤症状特点的22个特征以及它们的10个随意组合构成的干扰项进行特征选择,选择出使皮肤症状诊断率得到明显提高的特征组合。实验证明该方法是可行的。 相似文献
89.
针对激光干扰效果评估受主观经验较大、难以定量评估的问题,提出了一种基于深度学习的激光干扰效果评估方法.首先,对YOLOV5算法进行了整体介绍,其次制作了来自不同角度、不同距离的3020张激光干扰图像;然后,对标注的数据集进行训练,得到了激光干扰效果评估模型;最后,分别在YOLOV5x、YOLOV51、YOLOV5m、YOLOV5s网络模型下训练300次,实验验证了模型的正确性.实验结果表明:利用训练好的模型实现了对激光干扰图像的效果评估,该模型不仅可以自动标注激光干扰区域和进行干扰效果等级评估,同时还融入了传统策略,可以通过计算标注区域面积占整幅图像面积的大小作为辅助决策,实现自动标注激光干扰区域面积所占百分比,识别准确度在80%以上,对激光干扰效果评估具有重要意义. 相似文献
90.
Zhihui Liao Yuanpeng Xie Lie Chen Yun Tan Shaorong Huang Yongkang An Hwa Sook Ryu Xiangchuan Meng Xunfan Liao Bin Huang Qian Xie Han Young Woo Yanming Sun Yiwang Chen 《Advanced functional materials》2019,29(10)
The fluorobenzotriazole (FTAZ)‐based copolymer donors are promising candidates for nonfullerene polymer solar cells (PSCs), but suffer from relatively low photovoltaic performance due to their unsuitable energy levels and unfavorable morphology. Herein, three polymer donors, L24 , L68 , and L810 , based on a chlorinated‐thienyl benzodithiophene (BDT‐2Cl) unit and FTAZ with different branched alkyl side chain, are synthesized. Incorporation of a chlorine (Cl) atom into the BDT unit is found to distinctly optimize the molecular planarity, energy levels, and improve the polymerization activity. Impressively, subtle side chain length of FTAZ realizes a dramatic improvement in all the device parameters, as revealed by the short‐current density (Jsc) improved from 7.41 to 20.76 mA cm?2, fill‐factor from 36.3 to 73.5%, and even the open‐circuit voltage (Voc) from 0.495 to 0.790 V. The best power conversion efficiency (PCE) of 12.1% is obtained from the L810‐based device, which is one of the highest values reported for FTAZ‐based PSCs so far. Notably, the corresponding external quantum efficiency curve keeps a very prominent value up to 80% from 500 to 800 nm. The notable performance is discovered from the reduced energy loss, improved molecular face‐on orientation, the down‐shifted energy levels, and optimized absorption coefficient regulated by side‐chain engineering. 相似文献