～1.2 V open-circuit voltage from organic solar cells

Organic solar cells (OSCs) have achieved rapid advance due to the continuous development of high-performance key materials.Recently,the power conversion efficiencies (PCEs)of OSCs under 1 Sun condition (AM 1.5 G,100 mW/cm2) are striving toward 19％[1-5].The PCE improvement benefits from the largely enhanced short-circuit current density (Jsc) and fill factor (FF).However,these cells show relatively low open-circuit voltage (Voc) around 0.8-0.9 V.The rise of Internet of Things (loT) industry has promoted the indoor application of solar cells.OSCs can afford higher PCEs under various indoor light as compared to 1 Sun condition[6,7],but they present lower Voc[8].Fabricating tandem devices is an effective strategy to boost the performance of OSCs.Sub-cells with syn-chronously high Voc,Jsc and FF are highly desired in tandem cells,while these sub-cells are still limited[9].Thus,improving Voc without sacrificing Jsc and FF is an urgent mission in OSCs.     

试论基带数字与模拟视频测量的区别

随着广播电视技术迅速走向数字时代 ,电视技术发生了一系列巨大的变化 ,出现了许多不同的新系统和新技术。在节目制作方面 ,从普通的模拟复合到模拟分量 ,到数字复合、数字分量、压缩数字分量 ;还出现了非线性编辑网络、虚拟演播室等。在传输方面 ,不仅演播室到发射台的传输采用了数字方式 ,卫星电视广播也主要采用数字方式。数字电视技术已经从原来的模拟环境中单独一两台数字设备发展到数字岛 ,再发展到几个数字岛连成一片。数字电视系统规模越来越大 ,数字视频系统的指标测量 ,越来越引起人们的关注。那么 ,数字视频系统有哪些指标 ,怎么…     

双芯片张光分插复用器的理论分析和设计

本文介绍了双芯光纤光分插复用器的工作原理、结构和功能,并利用耦合模理论分析了器件的工作特性,讨论了各部分参数对上／下路特性的影响。结果表明,为同时实现上路和下路功能,应尽可能使用强光纤光栅以缩短光纤的长度并同时维持高反射效率。     

西藏羊八井实验C^2n测量与分析

本文利用了高灵敏度探测器测量了西藏羊八井这一特殊地形近地面的折射率结构常数。测量结果表明：尽管西藏羊八井地方的海拔高,但近地面湍流很强,这可能是由该地区的太阳辐射强以及下垫面地形等因素造成的。     

行波电极型BOA光开关的研制

设计了行波电极型GaAs异质结材料BOA光开关;采用谱域法分析和设计了平面微带线结构(PMS),并应用转移矩阵理论和有效折射率法计算和分析了电极结构与器件半波电压和串音度的关系。结果表明,采用PMS结构器件的3dB带宽可达到20GHz;电极位置的对称性对器件串音度起决定性的影响,采用本文提出的电极对准工艺,能够得到小于—40dB的串音度。     

混沌跳频通信的非线性自适应预测对抗

基于混沌跳频码序列构造固有的确定性、非线性等特点,提出了对抗混沌跳频通信的非线性自适应预测对抗的新概念.以Logistic-Kent映射设计的混沌跳频码为例,采用基于Sigmiod函数的Volterre自适应滤波预测器对其进行预测研究.仿真实验结果表明非线性自适应预测器比神经网络预测器具有更高的预测对抗效果.     

光子吸收诱导无序技术的光荧光谱研究

运用 1 0 6 4μm连续输出的Nd∶YAG激光器 ,对与InP晶格匹配的InGaAsP四元系量子阱材料进行了光子吸收诱导无序 (PAID)技术的研究。通过光荧光谱 (PL)的测量 ,证明有量子阱混合现象产生。衬底预加热和聚焦激光束结果表明 ,PAID中辐照时间与衬底温度、辐照的平均功率密度密切相关。聚焦激光照射后的荧光双峰表明PAID有一定的定域处理能力。     

BBO晶体Ⅰ型非共线相位匹配参量放大研究

理论研究了BBO晶体在Ⅰ型相位匹配下非共线情况时的激光参量放大特性。研究结果表明 ,对于一定波长的抽运光 ,存在一定的非共线入射角对应一定波长的信号光 ,使在较高的激光增益下增益带宽最大 ,同时温度的调谐也对增益谱的形状有部分影响。这对于短激光脉冲的激光参量放大的优化具有重要意义。     

DS-CDMA系统中PN码定时跟踪新算法及其实现

定时跟踪是DS-CDMA系统中Rake接收的关键技术,性能的好坏直接影响着扩频系统能否正常接收.文中首先对扩频系统中定时跟踪原理做出分析,然后重点介绍了PN码的"基于能量窗重心的定时跟踪"新算法,并选择了这个算法来实现CDMA2000-1x上行链路的PN码定时跟踪.最后,经过在典型城市环境下的现场实测,误帧率达到CDMA2000-1x的标准要求.     

Hierarchically Porous Multimetal‐Based Carbon Nanorod Hybrid as an Efficient Oxygen Catalyst for Rechargeable Zinc–Air Batteries

The lack of efficient strategies to address the intrinsic activity, site accessibility, and structural stability issues of metal‐carbon hybrid catalysts is restricting their real‐world implementation on the basis of rechargeable zinc–air batteries. Herein, a dual metal–organic frameworks (MOFs) pyrolysis strategy is developed to regulate the intrinsic activity and porous structure of the derived catalysts, where a Fe₂Ni_MIL‐88@ZnCo_zeolitic imidazolate framework (ZIF), with a hierarchically porous structure, multifunctional components, and an integrated architecture, acts as an ideal precursor to obtain multimetal based porous nanorod (FeNiCo@NC‐P). Benefitting from the synergetic effect of the multimetal components, facilitated reactant accessibility, and the well‐retained integrated structure, the resultant FeNiCo@NC‐P catalyst exhibits an oxygen reduction reaction half‐wave potential of 0.84 V as well as an oxygen evolution reaction potential of 1.54 V at 10 mA cm^–2. Furthermore, the practical application of FeNiCo@NC‐P in the zinc–air battery displays a low voltage gap and long‐term durability (over 130 h at a current density of 10 mA cm^–2), which outperforms the commercial noble metal benchmarks. This work not only affords a competitive bifunctional oxygen electrocatalyst for zinc–air batteries but also paves a new way to design and fabricate MOF‐derived materials with tunable catalytic properties.