利用非线性效应减小光纤偏振模色散

数据模拟了非线性功率脉冲在光纤中的脉冲演化过程，发现利用非线性可以压缩每一脉冲的偏振分量和减小偏振模色散（ＰＭＤ）。     

基于增强终端的统一Centrex组网实现

本文分析了现有的统一Centrex组网架构及实现机制,提出了将一部分处理能力由网络推向终端、增强终端能力的业务实现方式,以减少对智能网的建设。文中描述了终端软件的开发,以及相关的组网架构和信令流程,讨论了业务数据同步的问题。     

Novel organic dye employing dithiafulvenyl-substituted arylamine hybrid donor unit for dye-sensitized solar cells

In order to increase electron-donating ability of the donor part of the organic dye, two dithiafulvenyl (DTF) units were introduced into a triphenylamine unit to form dithiafulvenyl-substituted triphenylamine hybrid donor for dye-sensitized solar cells (DSSCs) for the first time. Novel donor–acceptor organic dye WD-10 containing this hybrid donor and 2-cyanoacetic acid acceptor has been designed, synthesized and applied in DSSCs. The influence of the substituent unit DTF in the dye on the device performance has been investigated. It was found that the dye with dithiafulvenyl-substituted triphenylamine hybrid donor gave higher photocurrent, open-circuit voltage, and efficiency value. The DSSC based on organic dye WD-10 displayed a short-circuit current (J_sc) of 9.58 mA cm^?2, an open-circuit voltage (V_oc) of 648 mV, and a fill factor (ff) of 0.71, corresponding to an overall conversion efficiency of 4.41%. An increase in η of about 79% was obtained from simple triphenylamine dye L0 to WD-10. The different photovoltaic behaviors of the solar cells based on the organic dyes were further elucidated by the electrochemical impedance spectroscopy. This work identifies that the introduction of DTF unit into the simple triphenylamine dye could significant improve the photovoltaic performance.     

基于迁移学习的机场场面目标检测与跟踪技术研究

本文分析了深度学习技术的基本原理,讨论了其应用与目标检测与跟踪领域的基本方式.利用实地采集的广汉机场场面视频数据,采用深度迁移学习的策略,研究了面向机场场面目标的检测与跟踪技术.     

基于光压原理的高功率激光测量装置

建立了一套基于光压原理的高功率激光测量装置,其功率测量不确定度优于2%(置信因子k=2)。在0.6~15 kW功率范围内将光压方法与量热方法进行了比较,得到的最大相对偏差小于1%。该装置的功率测量上限仅受限于激光反射镜的损伤阈值,因此其功率测量上限可达100 kW甚至更高,同时还具有响应速度快、测量准确度高、可在线测量等优点。     

科学家的社会公信力及其在风险治理中的角色

为建立完善我国的风险治理体系,急需一些具有较高社会公信力的专业群体参与公共危机管理。科学家是当前我国社会公信力最高的职业群体之一,调查显示九成以上的公众表示信任科学家,其信任水平远远高于其他职业群体。但我国科学家对公共危机管理的参与情况不容乐观,受到政府干预、媒体扭曲和自身动力不足等多重原因的阻碍。建议政府和社会应积极创造条件,鼓励科学家发挥其公信力的优势,参与公共危机事件治理。     

5G时代,有线接入网基础资源布局思路探讨

双千兆时代,网络规模空前巨大,有线接入网更是因覆盖范围广,建设规模大,投入人力多,投资占比高等因素,成为研究重点。文章根据有线接入网架构演进,从“点(各类业务及分纤点)、线(各级管线)、面(业务汇聚区)”三个层面对基站、家客、集客等业务接入、分纤点规划及业务汇聚机房等基础资源规划进行研究。     

Polarization Maintaining Air-Core Bandgap Fibers for Terahertz Wave Guiding

A polarization-maintaining air-core bandgap polymer fiber is proposed for low-loss terahertz (THz) wave guiding. The polarized guided modes are confined in an asymmetric core by a bandgap of periodic arrangement of square holes with round corners in the cladding. The guiding properties, including transmission bandwidth, numerical aperture, phase-index birefringence, modal absorption loss, and bend loss, are systematically investigated. The influence of background polymers on guiding properties is demonstrated in detail. Numerical simulations reveal that, while maintaining a relatively high phase-index birefringence (of the order of 10^-3 ), the THz fiber shows a significant suppression of absorption loss of the background polymers (by a factor of more than 25) due to the bandgap effect that repels the modal power from the absorbent polymers. The proposed THz fiber has potential for guiding intense THz waves for polarization-sensitive applications.     

液晶光阀的双稳态特性研究

测量了TB3639型液晶光阀在电压驱动下的光谱特性及其光学双稳态特性,并讨论其产生光学双稳态特性的非线性效应物理机制,分析了液晶光阀的光学双稳态特性不明显的原因.分析结果表明,扭曲角对液晶光阀的光学双稳态特性影响较大,由于TN型液晶光阀的扭曲角只有90°,导致其双稳态特性不是很明显,TB3639型液晶光阀在某一电压范围内存在光学双稳态特性.     

Respiration-Responsive Colorful Room-Temperature Phosphorescent Materials and Assembly-Induced Phosphorescence Enhancement Strategies

It is still very challenging to obtain colorful and long-afterglow room-temperature phosphorescent (RTP) materials from pure organic polymers. Herein, it is found that chitosan (CS), a natural polymer, not only has its own RTP, but also reacts with different phosphorescent molecules to obtain a multicolor, long-afterglow RTP material. CS can emit RTP with a lifetime of 48 ms. In addition, CS is rich in amino groups, and grafting different phosphorescent molecules onto CS by an amidation reaction can modulate it to emit different colors of phosphorescence and obtain a series of colorful CS derivatives. The obtained polymer films also have ultra-long RTP due to the good film-forming ability. In addition, one of the CS derivatives selected with α-cyclodextrin is used to construct RTP materials with lifetimes of up to seconds. The host–guest interactions are used to suppress nonradiative relaxation and build crystalline domains, thus synergistically enhancing the RTP. Interestingly, the RTP properties of the CS derivative films are extremely sensitive to water and heat stimuli, because water broke the hydrogen bonds between adjacent CS molecules and thus altered the rigid environment in the material. Finally, they can be used as a stimuli-responsive ink and for monitoring environmental humidity.