基于昆虫复眼技术的全视场运动目标监测系统

以昆虫复眼的仿生技术为基础,应用线阵CCD图像传感器、CPLD、AVR微处理器及运动目标检测算法实现了一种全视场监测系统,能简单而精确地探测出运动物体的角坐标和角运动速度。不仅对系统的硬件设计和软件设计进行了讨论,而且对应用的算法也进行了的介绍。     

Growth,characterization, and Raman spectra of the 1T phases of TiTe2, TiSe2, and TiS2

High-quality large 1$T$ phase of Ti$X_2$ ($X ={\rm Te}$, Se, and S) single crystals have been grown by chemical vapor transport using iodine as a transport agent. The samples are characterized by compositional and structural analyses, and their properties are investigated by Raman spectroscopy. Several phonon modes have been observed, including the widely reported $A_{1g}$ and $E_g$ modes, the rarely reported $E_u$ mode ($\sim$183 cm$^{-1}$ for TiTe$_2$, and $\sim$185 cm$^{-1}$ for TiS$_2$), and even the unexpected $K$ mode ($\sim$85 cm$^{-1}$) of TiTe$_2$. Most phonons harden with the decrease of temperature, except that the $K$ mode of TiTe$_2$ and the $E_u$ and "$A_{2u}$/Sh" modes of TiS$_2$ soften with the decrease of temperature. In addition, we also found phonon changes in TiSe$_2$ that may be related to charge density wave phase transition. Our results on Ti$X_2$ phonons will help to understand their charge density wave and superconductivity.     

空间站问天舱等离子体原位成像探测技术

等离子体原位成像探测器是中国空间站的第一批舱外空间环境科学载荷,安装在问天舱的舱外暴露平台,将首次在空间站平台上开展电离层等离子体原位、成像、充电电位等多要素综合探测任务.其中,原位探测要素包括空间站轨道等离子体的密度、温度以及问天舱表面电位强度等.成像探测要素包括离子能量、运动方向和成像时间分辨率等.等离子体原位成像探测器采用多传感器的一体化设计,集成了朗缪尔探针、阻滞势分析仪、参考电位计和离子成像仪等技术.其中,离子成像技术是首次应用于我国的空间环境探测领域.等离子体原位成像探测技术在中国科学院国家空间科学中心定标实验室完成了测试验证,探测器已随问天舱成功发射,即将开展中低纬电离层的精细化探测,为完善空间站轨道电离层模型提供等离子体探测数据.通过探测累积长周期的充电电位数据,为研究等离子体对空间站的充电效应,促进空间站充电评估体系的建立提供支持.