数字预失真系统的接收通道设计

根据数字预失真系统的要求,合理分配链路增益,考虑噪声和各部分级联影响,采用具有高线性度的无源下变频方案,并具体分析接收通道的整体响应,设计并制作了一个数字预失真功率放大器的接收通道.ADS仿真结果表明,设计的接收通道具有高线性度、小失真特性,输出三阶交调点OIP3的功率达到38.6 dBm.实验表明,该接收通道能很好地...     

激光测距机在线能量监测系统设计

本文基于无人值守条件下对激光测距机发射能量进行直接人工测量较为困难,为了防止激光器能量下降影响激光测距机性能,需要对测距机工作状态进行实时监控这一需求设计了激光测距机在线能量监测系统。对能量探头的结构与检测位置进行了研究,并设计硬件电路实现能量测量。本文设计的在线能量监测系统可以在不影响测距机测距能力的情况下实现kHz量级重频激光测距机的宽量程实时能量监测,并满足小型化、集成化设计要求。     

Improving the luminescence properties of Ba3Eu(PO4)3 by doping Sm3+ as sensitizer

For enhancing the emission intensity and broadening the excitation region of Ba3Eu(PO4)3 (BEP), Sm3+ is doped as sensitizer in this paper. BEP:Sm3+ can produce an obvious red emission at near ultraviolet (n-UV) radiation. An effective energy transfer from Sm3+ to Eu3+ is proved. The commission international de I’Eclairage (CIE) chromaticity coordinates of BEP:Sm3+ locate at red region. When the environment temperature is 150 °C, the emission intensity of BEP:0.10Sm3+ is decreased to 76% of the initial one at room temperature, and the activation energy is calculated to be 0.164 eV, which can prove the good thermal stability of BEP:Sm3+. The results indicate that BEP:Sm3+ may have potential applications in white light emitting diodes (LEDs).     

广西八角挥发油的提取研究与GC-MS分析

八角茴香(Illicium verum Hook.f)系木兰科八角属植物,主产于我国广西、云南、贵州等省[1].其中广西的产量占全国80%之多.