Electroluminescence and Laser Emission of Soluble Pure Red Fluorescent Molecular Glasses Based on Dithienylbenzothiadiazole

Soluble molecular red emitters 1a / 1b are synthesized by Stille coupling from 2‐(3,5‐di(1‐naphthyl)phenyl)thiophene precursors. The compounds show emission maxima at ca. 610 nm in CH₂Cl₂ solution and 620 nm in solid films. Replacing the n‐hexyl substituent by 4‐sec‐butoxyphenyl produces a marked increase of glass transition temperature (T_g) from 82 °C to 137 °C and increases the solubility in toluene and p‐xylene, thus improving the film‐forming properties. Cyclic voltammetry shows that the compounds can be reversibly oxidized and reduced around +1.10 and ?1.20 V, respectively. A two‐layered electroluminescent device based on 1b produces a pure red light emission with CIE coordinates (0.646, 0.350) and a maximal luminous efficiency of 2.1 cd A^?1. Furthermore, when used as a solution‐processed red emitter in optically pumped laser devices, compound 1b successfully produces a lasing emission at ca. 650 nm.     

一种利用反射电极偏压的半反半透LCD

介绍了一种VA模式反射电极偏压的常黑单盒厚半反半透LCD。在透射区,形成连续且均匀的贯穿液晶层的电场;而在反射区,电场则主要由电极表面形状控制。由此,可使透射区的位相延迟约是反射区的2倍。这样一种半反半透LCD不论透射区还是反射区都有很高的光透过率(>90%),同时二者灰阶特性重合度也很好。     

采用反射式液晶显示器和有机电致发光器件前后双置组合而成的高环境对比度显示器

一种高环境对比度(A-CR)和大开口率的显示器已经从理论上证明,并通过把一个正常显黑反射型显示器(NB-RLCD)和一个有机电致发光器件(OLED)堆垛的实验加以证明。这种前后双置(以下称为tandem型)的器件组合可以分别在明亮或昏暗的环境下切换NB-RLCD模式或OLED模式。RLCD的正常显黑特性也可以提升OLED模式工作时的A-CR性能。为了在RLCD模式下获得更好的图像品质,一个复杂并且具有传输功能的结构被用于消除镜面反射和提高可视角至CR﹥2:1超过55°的锥面可视角度。另外,这样的结构也可以提高OLED49.4%的表面量子效率。在我们的实验里,忽略环境亮度因素并使A-CR保持在100:1以上。     

非线性耦合KdV方程组的精确行波解

利用构造辅助函数和辅助常微分方程组的方法,给出了非线性耦合KdV方程的某些新的精确行波解,其中包括孤波解和周期解.     

A Differential-Mode Wideband Bandpass Filter on Microstrip Line for UWB Application

A differential-mode wideband bandpass filter (BPF) on microstrip line is proposed with good common-mode suppression. A four port two stage branch-line differential-mode BPF is first designed. Then, open circuited stubs are attached to the middle of two of the vertical branches. As such, its two-port bisection becomes a bandpass or bandstop filtering topology under differental- or common-mode excitations, respectively. The lengths and widths of these stubs can be properly adjusted to produce a highly attenuated and widened stopband under the common-mode operation. Finally, a wideband differential-mode BPF is designed and fabricated. The predicted and measured performances are in good agreement with each other, showing good common-mode suppression with an insertion loss higher than 20 dB over the differential-mode passband with a fractional bandwidth of 65%.     

基于可控随机变换的分形树生成算法及实现

分形树的生成算法是自然景物模拟中的热点问题,针对目前生成算法中的运行显示速度慢,树形变化少,颜色单一等问题,提出了一种可控随机交换的分形树生成算法.该算法对分形树的生成参数进行随机控制.给出了该算法的核心思想及实现过程,仿真实验得到了较好的生成显示速度及多姿态、多色彩的具有三维真实感的分形树.算法具有一定的通用性并可为其他自然景物的模拟提供较高的研究参考价值.     

基于CAN_GSM车辆监控系统设计

针对传统车辆监控系统的不足,提出了一种基于CAN／GSM的部队车辆监控系统。该系统采用CAN总线技术,依托GSM网络,将采集到的车辆信息实时传送到监控中心,并且采用动态参数设置,能够对车辆全面,实时地进行监控,具有很好的灵活性和扩展性。     

基于两相静止坐标系三相电压型PWM整流器控制策略的研究

本文研究了基于两相静止坐标系中的三相电压源型PWM整流器的控制方案,引入广义积分器实现三相电流在两相静止坐标系下跟踪控制。仿真结果证明了文中所提出的控制策略的有效性和可行性。     

An inchworm mobile robot using electromagnetic linear actuator

The capability of motion is one of the important aspects for a micro-robot to fulfill its given tasks. Micro-autonomous systems usually require large force, large displacement and less power consumption. Among different actuation schemes, electromagnetic actuator shows the benefit in a combination of force, displacement and cost effective control. A bristle-based inchworm mobile robot using a short stroke electromagnetic linear actuator is described in the paper. The main body and movable unit of the robot are joined by using a sealed bellows and the bristle legs are designed so that it can operate both on plane surfaces and in liquid. The actuator designed for the robot is a tubular type linear machine with an overall size of Φ7 × 10 mm. The key dimensions of the actuator were determined through magnetic field analysis to achieve optimum force output and necessary travel stroke within the limited space. The predicted actuation force of the actuator is 20 mN and the stroke length is 1.2 mm. Two working prototypes of the actuator were constructed and the performance tests show the effectiveness of the design. A sensorless control scheme with a novel start-up strategy for the designed actuator was developed based on the robotic system modeling and the analyzed results show the satisfactory performance of the system.     

Si衬底上ZnO外延膜结构性质的比较

采用连通式双反应室高温MOCVD系统在Si衬底上外延ZnO薄膜,通过卢瑟福背散射/沟道(RBS/C)及高分辨X射线衍射(HR-XRD)技术对不同衬底条件的ZnO外延膜进行了组分及结构分析,结果表明在采用SiC缓冲层后,Si(111)衬底上ZnO(0002)面衍射峰半高宽明显减小,缺陷密度降低,单晶质量显著变好,c轴方向应变由0.49%变为-0.16%,即由拉应变变为压应变且应变值变小,说明SiC缓冲层可以有效地减小ZnO与Si衬底晶格失配带来的应变,改善外延膜质量,实现Si衬底上单晶ZnO的生长.