解读2013 年度ENR 国际承包商250 强

2013 年度美国《工程新闻记录》评选的国际承包商榜单从225 强增加到250 强,在这一变化之下,对新的国际承包商250 强的情况进行了分析。从进榜企业的规模、效益、业务领域、行业及地区分布等方面对ENR 国际承包商250 强2012年的表现进行了统计分析。特别关注了2012 年国际承包市场上竞争热点地区和发展趋势。入围国际承包商250 强的中国内地企业被作为分析的重点,同时也追踪了近5 年ENR 国际承包商10 强的变动情况及市场和行业分布。对近5 年中国内地企业在榜单上的表现进行了纵向比较。通过深入分析2013 年度国际承包商250 强榜单,全面解读国际承包市场的变革和发展,为中国内地企业了解海外市场格局,拓展国际承包业务提供数据分析基础。     

以渣油为原料的中型氮肥厂技改方案（2）──中、低变串联工艺

阐述中、低变串联工艺的设计参数、消耗与能耗，介绍中、低变串联工艺方案与氨合成工艺方案及其特点．     

WBC250稳定土厂拌设备粉料系统的改造

针对WBC250稳定土厂拌设备粉料系统在现场施工存在的水泥流失量大，污染重的问题，并通过对改进后的进料不畅导致电机烧坏等新问题的分析，以理论为根据提出了在出料口处加装节流槽装置降低水泥的超量喷射，在料斗内加设第二层钢板增大水泥流动活性的解决方案，并在实践中逐步完善，对现有WBC250粉料系统的故障提出了彻底的改进方案。     

变截面涡旋盘高速铣削仿真加工与实验研究

为减小变截面涡旋盘涡旋齿的变形,提高加工精度,需确定合理的铣削参数。开展了变截面涡旋盘高速铣削仿真与实验研究以确定铣削参数的合理取值范围;选用HT250变截面涡旋盘为研究对象,研究了更接近实际的材料本构模型、刀-屑摩擦模型和热传导控制方程等关键技术;建立了变截面涡旋盘几何模型和简化后的二维铣削模型,利用ABAQUS软件仿真切屑成形过程及不同的铣削参数对铣削力、铣削热影响的变化曲线;通过多因素正交实验加工变截面涡旋盘。结果表明:当主轴转速为3500 r/min、每齿进给量为0.1 mm以及切削深度为2.5 mm时进行铣削更加合理。铣削变截面涡旋盘的研究为加工参数的选择提供了依据和参考;依据实验后所得的铣削参数进行铣削可减小铣削力、铣削温度及齿变形,提高了变截面涡旋盘的加工效率和质量。     

电子鼓电路HT3670C 及应用

HT3670C是HOLTEK公司为电子鼓音响应用而专门设计的CMOS VLSI芯片。文中介绍了它的内部结构、特点、功能及典型应用,并详细描述了它的韵律表和鼓键开关等功能。     

Electrical and interfacial properties of Au/P3HT:PCBM/n-Si Schottky barrier diodes at room temperature

In this study, a gold/poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester/n-type silicon (Au/P3HT:PCBM/n-Si) metal-polymer-semiconductor (MPS) Schottky barrier diode (SBD) was fabricated. To accomplish this, a spin-coating system and a thermal evaporation were used for preparation of a P3HT/PCBM layer system and for deposition of metal contacts, respectively. The forward- and reverse-bias current–voltage (I–V) characteristics of the MPS SBD at room temperature were studied to investigate its main electrical parameters such as ideality factor (n), barrier height (Φ_B), series resistance (R_s), shunt resistance (R_sh), and density of interface states (N_ss). The I–V characteristics have nonlinear behavior due to the effect of R_s, resulting in an n value (3.09) larger than unity. Additionally, it was found that n, Φ_B, R_s, R_sh, and N_ss have strong correlation with the applied bias. All results suggest that the P3HT/PCBM interfacial organic layer affects the Au/P3HT:PCBM/n-Si MPS SBD, and that R_s and N_ss are the main electrical parameters that affect the Au/P3HT:PCBM/n-Si MPS SBD. Furthermore, a lower N_ss compared with that of other types of MPS SBDs in the literature was achieved by using the P3HT/PCBM layer. This lowering shows that high-quality electronic and optoelectronic devices may be fabricated by using the Au/P3HT:PCBM/n-Si MPS SBD.     

Large-area organic photovoltaic module—Fabrication and performance

Here we describe the fabrication of the largest (233 cm² total area) organic photovoltaic (OPV) module (polymer:fullerene) to be certified by the National Renewable Energy Laboratory (NREL). OPV solar cells were fabricated at Plextronics by spin coating a blend of poly 3-hexylthiophene-2,5 diyl (P3HT) and [6,6] phenyl C₆₁ butyric acid methyl ester (PCBM) on top of our hole transport layer (HTL), Plexcore^® OC. In laboratory-scale devices (0.09 cm²), this system routinely exhibits power conversion efficiencies exceeding 3.7%. This P3HT:PCBM active layer and HTL ink system was used to scale up to the larger area module (15.2 cm×15.2 cm module size, i.e. 233 cm² total area; 108 cm² active area), which was certified by NREL as having 1.1% total area efficiency (3.4% active area efficiency).     

SINAMICS G120／PM250再生回馈型变频器在游梁式抽油机上的应用

本文主要介绍了西门子新一代再生能量回馈型变频器G120-PM250功率模块在游梁式抽油机上的成功应用，实现了游梁式抽油机运行时再生回馈电能的高效运行，达到了节能降耗和提高混油产量之目的。     

Detecting 6 MV X-rays using an organic photovoltaic device

An organic photovoltaic (OPV) device has been used in conjunction with a flexible inorganic phosphor to produce a radiation tolerant, efficient and linear detector for 6 MV X-rays. The OPVs were based on a blend of poly(3-hexylthiophene-2,5-diyl) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM). We show that the devices have a sensitivity an order of magnitude higher than a commercial silicon detector used as a reference. Exposure to 360 Grays of radiation resulted in a small (2%) degradation in performance demonstrating that these detectors have the potential to be used as flexible, real-time, in vivo dosimeters for oncology treatments.     

基于Intel PXA250处理器工作状态的功耗仿真模型及分析

设计了一个基于Intel PXA250处理器工作状态的功耗仿真模型，并且对SimIt-ARM的指令集模拟器进行修改，使其模拟Intel PXA250处理器，然后，为其添加上功耗分析模块，均用C 实现，试验结果表明，该模型在分析嵌入式处理器的工作状态变换引起的功耗变化方面具有良好的效果．