Synthesis and photovoltaic properties of an alternating phenylenevinylene copolymer with substituted-triphenylamine units along the backbone for bulk heterojunction and dye-sensitized solar cells

We have fabricated bulk heterojunction (BHJ) photovoltaic devices based on the as cast and thermally annealed P:[6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) blends and found that these devices gave power conversion efficiency (PCE) of about 1.15 and 1.60% respectively. P is a novel alternating phenylenevinylene copolymer which contains 2-cyano-3-(4-(diphenylamino)phenyl)acrylic acid units along the backbone and was synthesized by Heck coupling. This copolymer was soluble in common organic solvents and showed long-wavelength absorption maximum at 390-420 nm with optical band gap of 1.94 eV. The improvement of PCE after thermal annealing of the device based on the P:PCBM blend was attributed to the increase in hole mobility due to the enhanced crystallinity of P induced by thermal treatment. In addition, we have fabricated BHJ photovoltaic devices based on the as cast and thermally annealed PB:P:PCBM ternary blend. PB is a low band gap alternating phenylenevinylene copolymer with BF₂-azopyrrole complex units, which has been previously synthesized in our laboratory. We found that the device based on this ternary blend exhibited higher PCE (2.56%) as compared to either P:PCBM (1.15%) or PB:PCBM (1.57%) blend. This feature was associated with the well energy level alignment of P, PB and PCBM, the higher donor-acceptor interfaces for the exciton dissociation and the improved light harvesting property of the ternary blend. The further increase in the PCE with thermally annealed ternary blend (3.48%) has been correlated with the increase in the crystallinity of both P and PB. Finally, we used copolymer P as sensitizer for quasi solid state dye-sensitized solar cell and we achieved PCE of approximately 3.78%.     

带式果汁榨取机的开发与研制

以我国自行开发研制的１０ｔ／ｈ带式果汁榨取机为例，介绍了该设备的工作原理、主技术关键。     

纸机高精度O型扫描架机械系统的研制

分析了国内外纸机测控系统开发与应用的现状，结合工程实践对扫描架的设计、调试和创新，包括采用钢带传动、设置补偿机构、增加密封装置等进行了阐述。并对扫描架的研制过程、现场安装、调试及运行中取得的经验作了介绍。     

企领造型结构变化的实质

针对企领造型特征及领底线曲度与领面领座之间的关系，以及隐蔽领座企领的特点和设计方法等相关问题进行探讨，力求揭示其内在的变化规律，以便使企领的设计更简洁、规范、合理。     

近红外技术在玉米品质检测中的应用

近红外光谱检测技术因其独特的技术优势在玉米领域中开展了广泛的应用研究。首先对近红外检测原理及分析方法进行了介绍,阐述了在光谱预处理、波段优选及校正建模过程中的常用算法,然后介绍了目前近红外光谱技术在玉米杂交纯度检测、单倍体鉴别、品种鉴定以及成分检测方面的应用现状,着重说明了在定性和定量分析中取得的成果,最后就目前应用研究中的一些共性问题进行了总结,包括环境设备、样本选取、数据处理方式等因素对预测模型的精度和传递性的影响,并针对这些问题提出了后续研究展望,以期望近红外光谱技术在玉米品种检测中取得更大的进展。     

New explicit current/voltage equation for p‐i‐n solar cells including interface potential drops and drift/diffusion transport

Analytical modeling of p‐i‐n solar cells constitutes a practical tool to extract material and device parameters from fits to experimental data, and to establish optimization criteria. This paper proposes a model for p‐i‐n solar cells based on a new approximation, which estimates the electric field taking into account interface potential drops at the intrinsic‐to‐doped interfaces. This leads to a closed‐form current/voltage equation that shows very good agreement with device simulations, revealing that the inclusion of the interface potential drops constitutes a major correction to the classical uniform‐field approach. Furthermore, the model is able to fit experimental current/voltage curves of efficient nanocrystalline Si and microcrystalline Si p‐i‐n solar cells under illumination and in the dark, obtaining material parameters such as mobility‐lifetime product, built‐in voltage, or surface recombination velocity. Copyright © 2012 John Wiley & Sons, Ltd.     

Solution processed high band‐gap CuInGaS2 thin film for solar cell applications

A high band‐gap (~1.55 eV) chalcopyrite compound film (CuInGaS₂) was synthesized by a precursor solution‐based coating method with an oxidation and a sulfurization heat treatment process. The film revealed two distinct morphologies: a densely packed bulk layer and a rough surface layer. We found that the rough surface is attributed to the formation of Ga deficient CuInGaS₂ crystallites. Because of the high band‐gap optical property of the CuInGaS₂ absorber film, a solar cell device with this film showed a relatively high open circuit voltage (~787 mV) with a power conversion efficiency of 8.28% under standard irradiation conditions. Copyright © 2013 John Wiley & Sons, Ltd.     

超宽带高线性低噪声放大器的研制

随着雷达技术以及现代移动通讯的不断发展,系统对低噪声放大器的带宽、线性、低噪声提出了更高的要求.一个性能良好的低噪声放大器可大大改善接收机系统的信噪比.本文从宽带匹配和噪声的角度出发分析了超宽带高线性低噪声放大器的设计,利用ADS软件的辅助设计,实现了一种在30MHz-1350MHz频段的高线性低噪声放大器.通过采用视...     

A low‐voltage band‐gap reference circuit with second‐order analyses

A new band‐gap reference (BGR) circuit employing sub‐threshold current is proposed for low‐voltage operations. By employing the fraction of V_BE and the sub‐threshold current source, the proposed BGR circuit with chip area of 0.029mm² was fabricated in the standard 0.18µm CMOS triple‐well technology. It generates reference voltage of 170 mV with power consumption of 2.4µW at supply voltage of 1 V. The agreement between simulation and measurement shows that the variations of reference voltage are 1.3 mV for temperatures from ?20 to 100^°C, and 1.1 mV per volt for supply voltage from 0.95 to 2.5 V, respectively. Copyright © 2010 John Wiley & Sons, Ltd.     

新型模糊控制策略在带钢纠偏控制系统中的应用

详细阐述了一种新型模糊控制策略的原理,并将其应用到带钢纠偏控制系统中,通过仿真和实测证明了这种模糊控制策略在带钢纠偏系统中的有效性.