A transition solvent strategy to print polymer:fullerene films using halogen-free solvents for solar cell applications

Inkjet printing is a mask-less non-contact deposition technique that is potentially suited for prototyping and manufacturing of thin-film polymer organic semiconductor devices from digital images. However new strategies are needed to achieve films with good macromorphology (i.e., high-fidelity footprint and uniform cross-section) and nanomorphology on unstructured substrates using a conventional ink-jet. Here we report a new transition solvent strategy to provide the desired film macromorphology and ultrafine nanomorphology in regioregular poly(3-hexylthiophene):phenyl-C₆₁-butyric acid methyl ester (P3HT:PCBM) model films, without using chlorinated solvents. This strategy employs a good volatile solvent in combination with a miscible poor solvent that is much less volatile, which is the reverse of the usual low−high boiling-point solvent method. The good solvent suppresses premature aggregation in the ink head. Its removal by evaporation on the substrate leaves the poor solvent that triggers early π-stacking ordering and/or gelation of the polymer matrix that immobilizes the printed fluid on the substrate, suppressing both contact-line depinning and evaporation-induced solvent flow effects. The resultant donor–acceptor nanomorphology is further improved by vacuum drying at an optimal rate that avoids bubble formation. We have systematically characterized P3HT:PCBM films deposited with different solvents and platen temperatures to identify key macro- and nano-morphology determining processes. High-performance printed P3HT:PCBM solar cells were realized. These findings are applicable also to other printing and coating techniques based on low-viscosity inks.     

Influence of morphology on the behaviour of electrodes in a proton-conducting Solid Oxide Fuel Cell

SrCe_0.95Yb_0.05O₃ (SCY) and related materials are under consideration as a proton conductors for Solid Oxide Fuel Cell (SOFC) electrolytes. Sintered pellets of SCY are used to perform impedance spectroscopy (IS) studies and fuel cell tests on cells with Pt electrodes of two different morphologies. Electrodes are applied to the SCY pellets by two routes: either by firing on a layer of Pt paint (denoted electrode P) or by magnetron sputtering (electrode S). In impedance spectra recorded over a wide temperature range under humidified hydrogen, in symmetrical cell conditions, cells with S electrodes give rise to a much smaller low frequency impedance feature than the cells with P electrodes. This is tentatively attributed to faster diffusion-related processes taking place at the S electrodes. The behaviour of working fuel cells with S and P electrode morphologies is evaluated in terms of maximum power output and Area Specific Resistance in two-atmosphere tests. The fuel cell anode with the S morphology results in superior fuel cell performance, in agreement with the impedance study. The influence of the two different electrode morphologies on the behaviour of the cells is discussed with reference to their morphology, as determined by SEM and AFM.     

Fracture behavior and environmental stress cracking resistance (ESCR) of HIPS/PE blends and the effect of compatibilization on their properties

Attempts have been made to study the fracture behavior and environmental stress cracking resistance (ESCR) of HIPS/PE blends. The effect of compatibilization on their properties was also studied. EWF tests were conducted to measure the essential specific work of fracture (w_e) and non-essential specific work of fracture (βw_p). The ESCR of the samples was investigated using a special modified tensile creep test under an aggressive environment (sunflower oil). It was found that EWF methodology could be applied to uncompatibilized and compatibilized HIPS/PE blends as well as HIPS. The essential specific work of fracture of compatibilized HIPS/PE blends was higher than uncompatibilized HIPS/PE blends and pure HIPS, while its non-essential work of fracture was higher than uncompatibilized blends and lower than pure HIPS. The results also showed that the ESCR of HIPS decreases with incorporation of PE, but an effective compatibilization of this blend increases its ESCR even higher than pure HIPS. The different properties of compatibilized and uncompatibilized blends and HIPS, in EWF and ESCR tests, were attributed to the different mechanisms of fracture in these materials. The different mechanisms of fracture were justified using morphological studies performed on fracture surfaces of each sample. SEM images showed that there is a reasonable correlation between mechanisms of fracture and microstructure of the samples.     

基于故障暂态和数学形态学的超高速线路方向保护

引入数学形态学以提高基于故障暂态的超高速线路方向保护的动作性能。在获取连接在同一母线上的各条输电线路暂态电流信号的基础上，采用数学形态学分析其极性和能量以确定故障方向。仿真结果证明，该方法适用于识别发生在输电线路不同位置的各种故障。该方案对处理器的采样率、处理能力和速度几乎没有额外的要求，具有很好的实用性。与传统保护算法相比，基于MG的TBDP具有更高的可靠性和较少的计算量，同时具有更快的故障响应能力和更高的灵敏性。     

THMR-V道路检测算法设计

道路检测是室外移动机器人尤其是智能汽车研究领域的一个重要课题。本文介绍了多功能室外移动机器人THMR-V的道路检测算法,共分为两个部分。结构化道路,采用的是多窗口双阈值法。虽然在该领域已经有许多能够自主驾驶的系统,但很少能有像THMR-V达到150km/h;非结构化道路,采用的则是基于数学形态学的区域分割法。文中详细介绍了算法的实现。     

用于地图图像分色的像素边缘梯度算法

该文在分析地图图像特点的基础上,提出了一种适于地图分色的像素边缘梯度算法,其思想是将像素梯度的概念延伸到像素边缘的梯度。进而,利用数学形态学的变换原理,探讨了对分色结果进行后处理以及细化的具体过程。棕版图的实验结果证明,用此算法提取线状信息定位精度高,连续性好,处理速度快,并可以很好地解决粘连及背景噪声等问题,细化后的结果能够满足需要。     

蓖麻油基COPU／PMMA IPN的合成性能和形态结构的研究

研究了ＩＰＮ ＣＯＰＵ／ＰＭＭＡＢ预聚体合成的表观动力学。研究了ＩＰＮＣＯＰＵ／ＰＭＭＡ的物性及力学性，并用透射电镜研究了其形态结构。实验结果表明，此种ＩＰＮ材料具有良好的性能，如力学强度和化学稳定性。ＣＢ     

一种新的大型四肢动物体姿态识别方法

文中以对鹿体姿态的识别为例,针对鹿体姿态的特点,提出了一种新的可应用于大型四肢动物体姿态识别的方法。首先采用数学形态学的方法对图像进行了处理,获得了鹿体图像的准确轮廓,然后分别用四个椭圆对所获得的图像中鹿的颈部、去除颈部的躯干以及四肢进行拟合,最后利用线性代数的知识分别求出这四个用以表征鹿体姿态信息的椭圆的长短轴长度和方向。     

基于形态梯度运算的遥感图像边缘检测

针对常规线性边缘检测器处理遥感图象时细节丢失严重的缺点,介绍了数学形态学基本理论,讨论了数学形态学在边缘检测中的应用.形态学的灰度梯度运算是在经典形态变换基础上提出的一类非线性算子.对于结构元素的选取作了一定的说明.另外,还与传统线性算子的处理结果进行了比较.通过计算机对遥感图像的模拟实验表明：基于形态灰度梯度运算的遥感图像边缘检测方法,不但几何意义明确,易于构造,而且性能也优于传统检测算子,证实了该方法的可行性.     

Preparation of Oil-Encapsulated Microcapsules and Tribological Property of Ni Composite Coating

Microcapsules containing oil are potential candidate materials for preparing electrocomposite coatings with excellent tribological properties. In the present study, the preparation of oil-encapsulated microcapsules and electrodeposition of Ni-microcapsule composite coating are presented along with the properties of the coating. In situ interfacial polymerization method was used for the preparation of lubricating oil-encapsulated urea-formaldehyde microcapsules. The synthesized microcapsules were incorporated into the nickel matrix by electrodeposition using Ni-Watts bath. The Ni-composite coating containing microcapsules exhibited smaller Ni grain size, higher microhardness and lower surface roughness compared to plain Ni coating. Electrodeposited Ni coating containing oil-encapsulated microcapsules exhibited improved tribological properties with lower wear loss and coefficient of friction compared to plain nickel coating.