Surface modifications of ITO electrodes for polymer light-emitting devices

Surface modifications were performed on the indium tin oxide (ITO) substrates for polymer light-emitting devices, using the different treatment methods including solvent cleaning, hydrochloric acid treatment and oxygen plasma. The influence of modifications on the surface properties of ITO electrodes were investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle, and four-point probe. The surface energies of the ITO substrates were also calculated from the measured contact angles. Experimental results demonstrate that the surface properties of the ITO substrates strongly depend on the modification methods, and oxygen plasma more effectively improves the ITO surface properties compared with the other treatments. Furthermore, the polymer light-emitting electrochemical cells (LECs) with the differently treated ITO substrates as device electrodes were fabricated and characterized. It is observed that the surface modifications on ITO electrodes have a certain degree of influence upon the injection current, luminance and efficiency, but hardly upon the turn-on voltages of current injection and light emission which are close to the measured energy gap of electroluminescent polymer. Oxygen plasma treatment on the ITO electrode yields the better performance of the LECs, due to the improvement of interface formation and electrical contact of the ITO electrode with the polymer blend in the LECs.     

On Two Measures of Problem Instance Complexity and their Correlation with the Performance of SeDuMi on Second-Order Cone Problems

We evaluate the practical relevance of two measures of conic convex problem complexity as applied to second-order cone problems solved using the homogeneous self-dual (HSD) embedding model in the software SeDuMi. The first measure we evaluate is Renegar's data-based condition measure C(d), and the second measure is a combined measure of the optimal solution size and the initial infeasibility/optimality residuals denoted by S (where the solution size is measured in a norm that is naturally associated with the HSD model). We constructed a set of 144 second-order cone test problems with widely distributed values of C(d) and S and solved these problems using SeDuMi. For each problem instance in the test set, we also computed estimates of C(d) (using Peña’s method) and computed S directly. Our computational experience indicates that SeDuMi iteration counts and log (C(d)) are fairly highly correlated (sample correlation R = 0.675), whereas SeDuMi iteration counts are not quite as highly correlated with S (R = 0.600). Furthermore, the experimental evidence indicates that the average rate of convergence of SeDuMi iterations is affected by the condition number C(d) of the problem instance, a phenomenon that makes some intuitive sense yet is not directly implied by existing theory.     

An Economical Magnetocardiogram System Based on High-To SQUIDs

An economical magnetocardiogram （MCG） system is built in our laboratory. It mainly consists of a MCG data acquisition stage equipped with two high-To superconducting quantum interference device （SQUID） magnetometers, a data processing stage with digital filtering and a one-layer μ-metal magnetically shielded room in conjunction with a high-Tc SQUID based active compensation. Experimental results show that a noise level of pico-tesla in MCG profiles, which is necessary for clinical applications, may be achieved with the system. Moreover, stable and convenient operations of the system are demonstrated with simulating MCG measurements.     

湍流大气中光波闪烁的计算及实验测量比较

采用修正Rytov方法和近似理论计算了球面波在湍流大气中传播的闪烁指数，并与实验结果进行了比较，发现在弱起伏和中等湍流起伏区修正Rytov解与实验结果符合得良好，而在饱和区采用考虑内尺度效应下的近似理论结果更符合实验结果。     

Temperature dependence of excitonic luminescence from nanocrystalline ZnO films

The properties of the excitonic luminescence for nanocrystalline ZnO thin films are investigated by using the dependence of excitonic photoluminescence (PL) spectra on temperature. The ZnO thin films are prepared by thermal oxidation of ZnS films prepared by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique. The X-ray diffraction (XRD) indicates that ZnO thin films have a polycrystalline hexagonal wurtzite structure with a preferred (0 0 2) orientation. A strong ultraviolet (UV) emission peak at 3.26 eV is observed, while the deep-level emission band is barely observable at room temperature. The strength of the exciton-longitudinal-optical (LO) phonon coupling is deduced from the temperature dependence of the full-width at half-maximum (FWHM) of the fundamental excitonic peak, decrease in exciton-longitudinal-optical (LO) phonon coupling strength is due to the quantum confinement effect.     

采用信息融合技术的IR／MMW复合导引头的目标跟踪

从误差测量环节入手，基于IR／MMW双模结构，采用信息融合处理技术提高其估计跟踪精度，最终达到降低制导误差，提高武器性能的目的，仿真结果验证了该方法的有效性。     

PIC单片机在激光电源中的应用研究

论述了单片机控制激光电源的原理，提出了产生PWM控制的基本思想及整个控制系统的硬件组成和软件设计方法。     

Serially-connected series-stub resonators for narrowband coplanar-stripline bandpass filters

In this letter, a coplanar stripline (CPS) series resonator composed of serially-connected series-stubs is proposed. This kind of resonator provides two transmission zeros close to the resonant frequency. With the proposed structure, the reactance slope parameters of the resonators are significantly increased and adjustable by changing the length ratio of the two series stubs. This is useful for designing narrowband filters which is difficult to realize with conventional series CPS resonators. The structures of the resonators are optimized for a lower radiation loss and used to design a narrowband Chebyshev bandpass filter. The simulation and experimental results show that the proposed filter provides multiple transmission zeros and high selectivity.     

智能同步光网络与多业务传送平台的应用

智能同步光网络(ASON)与多业务传送平台(MSTP)固其先进的智能性、可靠性、灵活性而得以发展和运用。本文根据智能光网络与多业务传送平台枝术的发展情况，结合北京通信传送网络的实际情况，探讨北京通信传送网的建设思路．     

The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

Speckle fields are the random light wave distributions produced when the light fields are scattered from random surfaces or a random medium. They appear in many optical phenomena that are related to light propagations[1,2] and have found wide appli-cations in a variety of scientific and technical fields. The examples of the recent impor-tant applications of speckles include the analysis of the movement of the granules[3], the three-dimensional imaging for the microstructures of metal nanocryst…