Nanonecklace of CdO through simple solution chemistry

CdO nanonecklace like structure with interconnected nanobeads were produced by air annealed Cd(OH)₂ nanowire structure thin film at 290 °C. Simple and low cost chemical route has been successfully employed for the synthesis of Cd(OH)₂ nanowires on fluorine doped tin oxide (FTO) coated glass substrates at room temperature (27 °C). Structural analysis confirmed the conversion of hydroxide phase to the oxide phase by annealing which also leads to change in optical band gap from 3.5 to 2.34 eV. The necklace like nanostructure represent unique surface morphology which can be emerged as a potential candidate towards wide range of applications in different fields of nanotechnology such as solar cell, gas sensor, supercapacitor and photo-catalyst.     

Side chain effect on photovoltaic properties of dibenzo[a,c]phenazine based donor–acceptor polymers

The electron–donor polymers containing dibenzo[a,c]phenazine (BPz) derivatives with 2,7-alkyl and 11,12-alkoxy substituted, PBDT-BPzC and PBDT-OBPz, respectively, were synthesized to investigate the photovoltaic effect of different side chain substitutions. The polymers exhibit similar physical properties, except the HOMO and LUMO of PBDT-BPzC are 0.18 and 0.15 eV deeper than PBDT-OBPz, resulting in the V_oc of polymer solar cells (PSCs) based on PBDT-BPzC are above 0.1 V higher than that of PBDT-OBPz. With the contribution of the superior V_oc, polymer PBDT-BPzC showed preferable photovoltaic performances, and the PCE reached 4.44%, which is 0.49% higher than PBDT-OBPz. This research reveals a preferred side chain substituted way to modify BPz unit, and gives an optimally developing the dibenzo[a,c]phenazine derivatives based electron–donor polymers.     

日本单片机汽车竞赛模式的教学实践研究

本文简要地介绍了日本单片机汽车竞赛的竞赛规则和举办情况。文中结合电子类课程教学实践的要求,制定了适合我国电子专业教学特点的单片机汽车竞赛规则和奖励办法,提出了举办本校单片机汽车竞赛的方式,鼓励学生参与创新型电子设计,以培养带动竞赛、以竞赛促进培养,为工科大学生实践教学提供了一条新思路。     

改进Hough变换在直线铁轨图像边缘检测研究

针对铁路轨道数字图像处理中直线铁轨检测的快速有效问题,提出一种改进Hough变换直线铁轨检测方法.首先对图像进行小波提升,用经典的边缘检测LoG算子进行图像的边缘检测;然后计算图像空间直线斜率重叠度来快速检测出直线;最后将图像转换到参数空间,计算局部极大值点,检测出直线.通过大量的仿真实验证明了该方法对直线铁轨检测的有效性和实用性.     

Synergism of molecular weight,crystallization and morphology of poly(3-butylthiophene) for photovoltaic applications

A serial of poly(3-butylthiophene) (P3BTs) with molecular weights (MWs) ranged from 7 kDa to 50 kDa is synthesized and characterized. The DSC studies show that the thermal property and crystallinity of P3BT increase with MWs within the range from 7 kDa to 25 kDa, then decrease with further higher MW. The characteristic morphologies of incontinuous crystalline nanofibrils, interconnected nanofibrillar networks, and relative large clusters associate to low, medium and high MW P3BTs, respectively, demonstrate the strong correlation between MW, crystallinity and morphology of P3BT. It is found that the P3BT could be re-considered as the promising candidate for applications in organic optoelectronics if synergism of the crystallinity and morphology could be precisely controlled via tuning molecular weight. The polymer solar cells (PSCs) device based on P3BT with medium MW achieves an attractive power conversion efficiency of 3.5%, which is, to the best of our knowledge, the record for P3BT/PC₆₁BM PSCs and comparable to the well-studied P3HT devices.     

用VC＋＋和Matlab混合开发软测量模型生成系统

在VisualC＋＋中调用Matlab程序进行软测量建模系统的开发,可以充分利用Matlab中丰富的数值计算函数,节省编写算法的时间,简化代码,也可以利用VisualC＋＋强大、灵活的开发特性。软件开发实践表明,Matlab和VisualC＋＋的混合编程实现简单,功能齐全,可很好地应用在工程应用软件等相关领域。     

Electronic structure of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) derivatives for organic solar cell applications

Among the new materials currently employed as electron donor element in active layers of organic solar cells (OSCs), PTB7 holds the best results. It has been extensively studied and now there is a search for new derivatives to improve its properties. In this work, a set of 24 polymers derived from polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) was studied theoretically, using chemical modifications in the benzodithiophene (BDT) moiety of the PTB7 monomeric units. After evaluations of the electronic and optical properties, including the open circuit voltage and exciton dissociation and recombination conditions, the results indicate that employing chlorine as substituent yields the most promising material for application in active layers together with Phenyl-C₆₁-Butyric-Acid-Methyl-Ester (PCBM) as electron acceptor material.     

MRAS 的无速度传感器矢量控制系统

为了实现矢量控制系统中异步电动机转速的闭环控制和磁场定向,对基于模型参考自适应系统(model reference adaptive system,MRAS)的无速度传感器矢量控制系统进行研究。从异步电机端测量得到的电压和电流来估算电机转速,在异步电动机无速度传感器矢量控制算法中,采用电流模型和电压模型进行磁链估算,基于MRAS方法构建异步电动机转子转速辨识模型,并在Matlab/Simulink中建立了异步电动机无速度传感器矢量控制仿真系统。仿真结果表明:该系统具有良好的动静态特性和稳定性。     

高校专业基础课程分层教学研究

分层教学模式对转变教与学的方式,进而实现因材施教,具有重要的研究和借鉴价值。专业基础课教学是大学阶段中最重要的环节之一。专业基础课的分层教学对于强化优秀学生的个性特征,激发普通学生学习的兴趣和自信具有积极意义。本文介绍了在分班、教学、考核等各个环节进行专业基础课分层教学的具体举措。为电工电子类课程以及其他专业基础课程教...     

Tumor segmentation in lung CT images based on support vector machine and improved level set

In lung CT images, the edge of a tumor is frequently fuzzy because of the complex relationship between tumors and tissues, especially in cases that the tumor adheres to the chest and lung in the pathology area. This makes the tumor segmentation more difficult. In order to segment tumors in lung CT images accurately, a method based on support vector machine (SVM) and improved level set model is proposed. Firstly, the image is divided into several block units; then the texture, gray and shape features of each block are extracted to construct eigenvector and then the SVM classifier is trained to detect suspicious lung lesion areas; finally, the suspicious edge is extracted as the initial contour after optimizing lesion areas, and the complete tumor segmentation can be obtained by level set model modified with morphological gradient. Experimental results show that this method can efficiently and fast segment the tumors from complex lung CT images with higher accuracy.