包层折射率变化的光纤温度传感器机理研究

本文从实验角度研究了两种光纤材料的折射率随温度变化的特性，讨论了包层折射率变化的光纤温度传感器机理，设计了一种高精度的包层折射率变化光纤温度传感器系统。     

基于级联长周期光纤光栅的新颖温度传感器

设计了一种基于级联长周期光纤光栅(Long period fiber grating)的新颖温度传感器.理论上得到光栅间光纤的长度随温度增加变化时,级联LPG的干涉峰将线性地向长波方向漂移,其消光比亦将呈现线性变化.实验上制作出了基于级联LPG的光纤温度传感器.利用其某一干涉峰的中心波长和消光比测量温度变化时,测量灵敏度分别为0.0353 nm/℃和0.0684 dB/℃.基于级联长周期光纤光栅的温度传感器具有广泛的应用前景.     

拉曼散射分布式光纤温度传感器的系统设计

拉曼散射分布式光纤温度传感器是集光学，电子，计算机应用技术和微弱信号检测技术于一体的复杂系统，它可以同时获取被测温度场的空间分布状态信息和时间变化信息，本文论述了分布式光纤温度传感器的设计方法，系统组成和实验评估。     

基于光纤的温度传感器

简单介绍了光纤温度传感器的原理及分类,并分别介绍了光纤Fabry-perot干涉型温度传感器、半导体吸收型光纤温度传感器、光纤光栅温度传感器的工作原理及最近几年来的研究现状,阐述了各种温度传感器的机理、实验装置和研究结果,最后对其进行了对比分析.     

光纤温度传感器的研究和应用

分析了光纤温度传感器在温度探测中的优势,综述了光纤温度传感器的发展现状和应用.分别介绍了分布式光纤温度传感器、光纤光栅温度传感器、干涉型光纤温度传感器、光纤荧光温度传感器和基于弯曲损耗的光纤温度传感器的工作原理和研究现状,详细介绍了各种传感器的特点及各自的研究方向.     

分布式光纤温度传感器的原理和应用

分布式光纤温度传感器是近年来开始研究的新型传感技术，它可以同时获取被测温度场 空间分布状态和随时间变化的信息。文章讨论了分布式光纤温度传感器的工作原理，设计思想、研究现状及应用前景。     

光纤高温传感器的研究进展及应用

对高温光纤温度传感器的最新研究进展做了简单的归纳和总结,阐述了几种典型的光纤高温传感器,对各种光纤传感器的工作原理和特点进行了详细的论述,最后对其应用前景进行了展望.研究表明:高温光纤温度传感器具有优良的特性,能够在恶劣环境下测量极高的温度.     

新型透射式光纤温度传感器

本文根据双金属片随温度变化的原理，对利用光纤传我信号的透射光纤温度传感器进行了实验研究，其探头构思独特，结构简单，测温范围宽，可靠实用。     

基于乙醇灌注边孔光纤的Sagnac干涉型温度传感器

提出并研究了一种基于乙醇灌注边孔光纤(SHF)的Sagnac干涉型温度传感器。边孔光纤是一种高双折射光纤,其包层中纤芯两侧具有两个空气孔。将乙醇填充进边孔光纤的空气孔中,利用乙醇的折射率随温度的变化,改变边孔光纤的双折射系数,使Sagnac干涉仪的输出谱发生波长漂移,从而实现了温度传感。实验获得该传感器在20℃～80℃的温度变化范围内灵敏度为86.8pm/℃,为普通光纤布拉格光栅(FBG)传感器的8倍。     

医用光纤温度传感器的发展及应用

本文论述了医用光纤温度传感器在医学、生物学等研究领域里的应用以及该传感器的特点。综述了医用光纤温度传感器研究的发展过程和国内外的发展状况及发展趋势。     

聚合物水化分子的微观结构研究

在聚合物水化分子微观结构研究中,必需使用冷冻升华方法制样才能基本保持样品的聚合物分子形态与原水化状态一致。风干制样方法会导致聚合物分子链卷缩,样品干缩成块,无法保留水化分子的原貌。放大倍数小于2000X的显微图像适于研究聚合物水化分子构成的骨架全貌;而放大倍数大于10000X后,更适于观察聚合物水化分子骨架的局部形态。聚合物分子在溶液中形成非均匀网络骨架,存在较粗的主干和较细的分枝。这种网络骨架既对水分子形成支撑,又吸附和包裹大量水分子产生形变阻力。大部分网络骨架不是由单个聚舍物分子构成,而是由聚合物分子聚集体形成。溶液中的盐份富集在聚合物分子的带电基团附近并形成浓度梯度分布。     

MEMS/Sensor工艺中无定形碳应用及干法蚀刻研究

提出一套新的无定型碳牺牲层蚀刻工艺,新工艺应用于MEMS和Sensor牺牲材料工艺中,能够很好地解决无定形碳蚀刻工艺中有机副产物问题。在无定形碳蚀刻工艺中添加低浓度的CF4蚀刻气体(1%~5%),有助于去除在蚀刻过程中侧壁形成的有机副产物。在无定形碳蚀刻工艺前添加一步光刻胶硬化步骤,和在无定形碳蚀刻工艺后添加一步有机副产物各项异性蚀刻步骤,有助于去除表面产生的有机副产物。并针对新工艺去除无定形碳蚀刻过程中形成的有机副产物反应机制进行了详尽阐述与讨论。     

Electron Barrier Formation at the Organic‐Back Contact Interface is the First Step in Thermal Degradation of Polymer Solar Cells

Long‐term stability of polymer solar cells is determined by many factors, one of which is thermal stability. Although many thermal stability studies occur far beyond the operating temperature of a solar cell which is almost always less than 65 °C, thermal degradation is studied at temperatures that the solar cell would encounter in real‐world operating conditions. At these temperatures, movement of the polymer and fullerenes, along with adhesion of the polymer to the back contact, creates a barrier for electron extraction. The polymer barrier can be removed and the performance can be restored by peeling off the electrode and depositing a new one. X‐ray photoelectron spectroscopy measurements reveal a larger amount of polymer adhered to electrodes peeled from aged devices than electrodes peeled from fresh devices. The degradation caused by hole‐transporting polymer adhering to the electrode can be suppressed by using an inverted device where instead of electrons, holes are extracted at the back metal electrode. The problem can be ultimately eliminated by choosing a polymer with a high glass transition temperature.     

聚合物混合状态检测中信号特征提取技术研究

针对螺杆挤出机中聚合物挤出过程的混合状态的在线检测要求,研究聚合物混合状态的超声波脉冲检测的特征信号的提取技术。通过研究超声波在聚合物中的速度和能量的衰减,推测分散在基体中的分散状态等混合物的状态。实验表明：通过差分法提取聚合物混合物和单一聚合物的特征信号,可以明显提高特征值的精确度,获得较好的效果。本文为聚合物混合状态在线检测特征信号的提取提供方法参考。     

Enhancing the performance of non-fullerene solar cells with polymer acceptors containing large-sized aromatic units

In this work, we develop four diketopyrrolopyrrole-based polymer acceptors for application in polymer-polymer solar cells. The polymer acceptors contain different-sized aromatic units, from small thiophene to benzodithiophene and large alkylthio-benzodithiophene units. Although the polymer acceptor with large-sized groups shows small LUMO offset and low energy loss when blended with the donor polymer PTB7-Th, the corresponding solar cells can achieve a high power conversion efficiency (PCE) of 3.1% due to high photocurrent. In contrast, the polymer acceptor with small thiophene units only provides a low PCE of 0.14% in solar cells. These results indicate that polymer acceptors with large-sized aromatic units can be potentially used into high performance non-fullerene solar cells.     

Comparison of the Operation of Polymer/Fullerene,Polymer/Polymer,and Polymer/Nanocrystal Solar Cells: A Transient Photocurrent and Photovoltage Study

We utilize transient techniques to directly compare the operation of polymer/fullerene, polymer/nanocrystal, and polymer/polymer bulk heterojunction solar cells. For all devices, poly(3‐hexylthiophene) (P3HT) is used as the electron donating polymer, in combination with either the fullerene derivative phenyl‐C₆₁‐butyric acid methyl ester (PCBM) in polymer/fullerene cells, CdSe nanoparticles in polymer/nanocrystal cells, or the polyfluorene copolymer poly((9,9‐dioctylfluorene)‐2,7‐diyl‐alt‐[4,7‐bis(3‐hexylthien‐5‐yl)‐2,1,3‐benzothiadiazole]‐2,2‐diyl) (F8TBT) in polymer/polymer cells. Transient photocurrent and photovoltage measurements are used to probe the dynamics of charge‐separated carriers, with vastly different dynamic behavior observed for polymer/fullerene, polymer/polymer, and polymer/nanocrystal devices on the microsecond to millisecond timescale. Furthermore, by employing transient photocurrent analysis with different applied voltages we are also able to probe the dynamics behavior of these cells from short circuit to open circuit. P3HT/F8TBT and P3HT/CdSe devices are characterized by poor charge extraction of the long‐lived carriers attributed to charge trapping. P3HT/PCBM devices, in contrast, show relatively trap‐free operation with the variation in the photocurrent decay kinetics with applied bias at low intensity, consistent with the drift of free charges under a uniform electric field. Under solar conditions at the maximum power point, we see direct evidence of bimolecular recombination in the P3HT/PCBM device competing with charge extraction. Transient photovoltage measurements reveal that, at open circuit, photogenerated charges have similar lifetimes in all device types, and hence, the extraction of these long‐lived charges is a limiting process in polymer/nanocrystal and polymer/polymer devices.     

Nanoimprint Lithography and the Role of Viscoelasticity in the Generation of Residual Stress in Model Polystyrene Patterns

Understanding polymer deformation during the nanoimprinting process is key to achieving robust polymer nanostructures. Information regarding this process can be extracted from monitoring the decay of the imprinted polymer patterns during thermal annealing. In the present work, the effect of both the molar mass and the imprinting temperature on the pattern decay behavior during thermal annealing is investigated. Previously, it was found that the decay rate is fastest for a highly entangled polymer due to the elastic recovery caused by the residual stress created during the imprinting process. The present paper demonstrates that this residual stress level can be modified through control of the imprinting temperature. These results are contrasted with those for an unentangled polymer over a similar range of imprinting temperatures, where it is found that the pattern decay is controlled by simple Newtonian flow. In particular, the pattern decay is well described by surface‐tension‐driven viscous flow, and no imprinting‐temperature effect is observed during thermal annealing. It is shown that the stability of the film against pattern decay can be optimized for moderately entangled polymer films. This effect is attributed to the competition between the effect of increased viscosity with increasing molar mass and increased residual stresses with entanglements. These observations provide guidance for the optimization of imprinting process in terms of selection of molar mass and processing temperatures.     

Nanomorphology influence on the light conversion mechanisms in highly efficient diketopyrrolopyrrole based organic solar cells

In this work, diketopyrrolopyrrole-based polymer bulk heterojunction solar cells with inverted and regular architecture have been investigated. The influence of the polymer:fullerene ratio on the photoactive film nanomorphology has been studied in detail. Transmission Electron Microscopy and Atomic Force Microscopy reveal that the resulting film morphology strongly depends on the fullerene ratio. This fact determines the photocurrent generation and governs the transport of free charge carriers. Slight variations on the PCBM ratio respect to the polymer show great differences on the electrical behavior of the solar cell. Once the polymer:fullerene ratio is accurately adjusted, power conversion efficiencies of 4.7% and 4.9% are obtained for inverted and regular architectures respectively. Furthermore, by correlating the optical and morphological characterization of the polymer:fullerene films and the electrical behavior of solar cells, an ad hoc interpretation is proposed to explain the photovoltaic performance as a function of this polymer:blend composition.     

Donor acceptor type neutral state green polymer bearing pyrrole as the donor unit

A new neutral state green polymer, poly (2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline) (PTBPPQ) was synthesized and its potential use as an electrochromic material was investigated. Spectroelectrochemistry studies showed that polymer reveals two distinct absorption bands as expected for a donor–acceptor type polymer, at 408 and 745 nm. In addition, polymer has excellent switching properties with satisfactory optical contrasts and very short switching times. Outstanding optical contrast in the NIR region and stability make this polymer a great candidate for many applications. It should be noted that PTBPPQ is one of the few examples of neutral state green polymeric materials with superior switching properties. Hence, PTBPPQ can be used as a green polymeric material for display technologies.     

固体铝电解电容器用导电高分子制备工艺进展

依据近年的相关专利,综述了用于固体铝电解电容器的导电高分子的最新制备工艺,介绍了导电高分子固体铝电解电容器的结构,详细描述了制备导电高分子的两种主要方法——化学聚合和电化学聚合——及其进展历程。介绍了新颖掺杂剂的发现与使用,对各种工艺的特点进行了评述。