Organic Light‐Emitting Diode Sensing Platform: Challenges and Solutions

The organic light‐emitting diode (OLED)‐based sensing platform is gaining momentum due to unique attributes of the compact OLEDs that are used as excitation sources. This paper, however, points to issues related to this sensing platform that will affect many (bio)chemical sensing applications, in particular in photoluminescence (PL)‐based sensors operated in the advantageous time domain, where pulsed OLEDs are utilized. The issues are related to the post‐pulse electroluminescence (EL) profile, i.e., transient EL, which depends on the OLED materials and structure, and to the long‐wavelength tail of the typically broad‐band EL spectrum. Depending on materials and device structure, the transient EL may exhibit spikes peaking at ～100–200 ns and μs‐long tails. As shown, these interfere with the determination of PL decay times (that are related to analyte concentrations) of sensing elements. The results also indicate that the long‐wavelength tail of the EL spectrum contributes to the interfering post‐pulse μs‐long EL tail. Hence, it is shown that the choice of OLED materials, the use of microcavity (μC) OLEDs with tunable, narrower EL bands, and the use of UV OLEDs alleviate these issues, resulting in more reliable data analysis. Furthermore, a 2‐D uniform 2 μm‐pitch microlens array that was previously used for improving light extraction from the OLEDs (J.‐M. Park et al., Optics Express 2011 , 19, A786) is used for directional PL scattering toward the photodetector, which leads to a ～2.1–3.8 fold enhancement of the PL signal. This behavior is shown for oxygen sensing, which is the basis for sensing of bioanalytes such as glucose, lactate, ethanol, cholesterol, and uric acid.     

Impact of poly naphthalene sulfonate on the dispersion stability of iron oxide nanoparticles

Iron oxide nanoparticles (IOXn) are unstable in aqueous solutions, which prevents their use in various applications. Because of this, it was proposed to treat the IOXn surface by employing a dispersant like sodium poly (naphthalene formaldehyde) sulfonate (PNS). In a single easy process, the (IPNS) were made by covering the IOXn with PNS. The material's structure, morphology, and magnetic properties were identified using XRD, TEM, Zeta potential, FTIR, HR-SEM, and a VSM. Due to its complex molecular structure and high anionic charge density, the polymeric dispersant (PNS) displays various characteristics. PNS successfully modifies the IOXn surface to create excellent colloidal electrostatic stability. At pH = 8, the zeta potential decreased from ?13 to –23 mv. After the coating procedure, the crystalline structure changed into an amorphous one. The average particle size was decreased from 138 to 32 nm. In addition, there was a slight reduction in the magnetization saturation (Ms).     

Mechanical strength of Sn-3.5Ag-based solders and related bondings

The tensile strengths of bulk solders and joint couples of Sn-3.5Ag-0.5Cu, Sn-3.5Ag-0.07Ni, and Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge solders and the shear strengths of ball grid array (BGA) specimens, solder-ball-attached Cu/Ni/Au metallized substrates were investigated. The tensile strength of the bulk is degraded by thermal aging. The Ni-containing solder exhibits lower tensile strength than Sn-3.5Ag-0.5Cu after thermal aging. However, the Ni-containing solder joints show greater tensile strength than the Cu/Sn-3.5Ag-0.5Cu/Cu joint. Fracture of the solder joint occurs between the intermetallic compound (IMC) and the solder. The shear strength and fracture mechanism of BGA specimens are the same regardless of solder composition.     

利用固相反应法在硅片上制备硅酸锌发光薄膜及表征

采用与硅集成工艺相兼容的固相反应方法在硅衬底上制备了未经掺杂及掺锰的硅酸锌薄膜 .XRD测试和UV - Vis吸收谱测试证明在高于 880℃的温度下热处理 ,可以获得结晶状态很好的硅酸锌薄膜 .光致发光光谱分析表明 ,未掺杂的薄膜在紫外波段有较弱的发射 ,而掺锰的硅酸锌薄膜在可见光波段有很强的光致发射 .由于硅酸锌薄膜在高温下非常稳定 ,可以与硅集成电路工艺兼容 ,而且发光强度高 ,因此在制作硅基光电集成器件方面有非常大的应用前景     

基于并播技术的DVB发送卡设计

介绍了并行广播技术,提出了作为大规模信源的并行数据如何通过MPEG-2传输流数据发送卡实现这种海量传输的硬件实现方案,并分析了设计要点.     

ZnAl_(13)Cu_7MgSb锌合金时效组织和性能

研究了 Zn Al1 3Cu7Mg Sb锌合金经固溶处理和时效后的组织和性能。结果表明 ,在试验温度范围内 ,时效对该合金有明显的强化效果。时效早期 ,发生α′相的调幅分解 ,导致合金的硬度、σb 达到最大值。继续时效 ,调幅组织粗化和颗粒化 ,使合金的硬度、σb下降。时效后期 ,发生 α+ε→ T′+η反应 ,T′相的出现减缓了合金硬度、σb的下降。     

基于APROS的锅炉给水泵汽轮机MEH仿真控制研究

对锅炉给水泵汽轮机数字电液控制系统MEH进行了仿真研究,详细描述了转速自动控制回路调节器参数的整定过程,简单介绍了控制系统模型在APROS（Advanced Process Simulation）仿真支撑软件平台上的实现过程与转速自动控制原理,并通过仿真结果分析、验证了本文所采用的建模与整定方法,同时也为整定现场控制系统参数提供了参考依据。     

Optimizing the solar photo-Fenton process in the treatment of contaminated water. Determination of intrinsic kinetic constants for scale-up

The elimination of aromatic compounds present in surface water by photo-Fenton with sunlight as the source of radiation was studied. The concentrations of Fe³⁺ and H₂O₂ are key factors for this process. A solar simulator and a prototype parabolic collector were used as laboratory-scale reactors to find the parameters of those key factors to be used in the CPC (compound parabolic collector) pilot plant reactor. The initial mineralization rate constant (k_obs) was determined and evaluated at different Fe³⁺ and H₂O₂ concentrations to find the best values for maximum efficiency. In all the experiments the mineralization of an aqueous phenol solution was described by assuming a pseudo-first-order reaction. The intrinsic kinetic constants not dependent on the lighting conditions were also estimated for scale-up.     

ICP-AES法测定铸铁中Si、Mn、Cr、Ni的研究

研究了ICP-AES同时测定铸铁中的硅、锰、铬、镍4种元素的快速分析方法。通过试验确立了各元素的最佳光谱线和光谱仪合适的工作条件,并确定了各元素的检出限、测定下限,实现了ICP-AES法测定铁的快速分析、测定数据的精密度和准确度结果令人满意,方法快速、简便。     

基于权重迭代的偏好多目标分解算法解决参考点对算法影响的研究

在传统偏好多目标进化算法中,参考点是表达决策者的偏好信息最常用的方式,但是参考点所处位置信息有时严重影响算法的性能.针对以上问题,本文提出了一种基于权重迭代的偏好多目标分解算法(MOEA/D-PRE),主要利用权重迭代方法获取一组均匀的权重向量,并对偏好区域进行映射,使得算法在进化过程中,不用考虑参考点所处位置信息对算法性能的影响,另外提出了一种稳定可控的偏好区域模型,能响应决策者设置任意大小的偏好区域.通过对比实验表明该算法具有较好的收敛性和分布性,同时给出了满足决策者不同要求的算法模型,并且能够很好的解决参考点的位置信息对算法的影响.