基于单模光纤耦合的无线光通信系统设计

为了实现适用于近地的单模无线光设备,设计了一种单模接收无线光通信系统.提出了一种两级跟踪和孔径平滑的设计方法以抑制大气湍流及设备轻微晃动的影响.完成了900 m外场实验,实现了最大单模耦合接收效率为20％,两端接收功率跳动在6 dB以内.实验数据表明两级跟踪加权平均的方法可以抑制大气湍流及轻微晃动.最后,提出了下一步改...     

750 kV LGJK300/50扩径导线的有限元建模及模态分析

超高压扩径导线750 kV LGJK300/50型,因模型中股线间的接触为强非线性的点、线接触,参考相关有限元建模文献,很难找到理想的方法得到成功的有限元模型。针对这个难点,经过加大股线尺寸6～10个丝,改善原有的有限元模型,并对其进行模态仿真。模态仿真结果较之前的模型更优,更贴近实际。模态仿真结果显示,扩径导线在工程使用中的模态振型,主要以弯扭变形模态为主。当模型长度较短时,发生微风振动的几率较高,导线长度逐渐增加,次档距震荡会凸显,若无间隔棒,导线长度再逐渐增加时,则具有破坏性质的舞动随之而来,这与工程实际运行情况相符。     

一种大气激光通信变f数跟踪光学系统设计

针对常用四象限探测器,设计了一种大气激光通信变f数跟踪光学系统,实现了8.7倍变倍比,连续变焦范围75~650 mm,固定通光孔径60 mm。对设计光学系统进行了评价,光学系统传递函数,点列图和畸变性能优良,满足系统要求。完成了系统凸轮曲线分析,结果表明系统变焦轨迹平滑,可以保证变焦过程系统同轴性。     

750 kV LGJK300/50扩径导线的有限元建模及模态分析（英文）

超高压扩径导线750 kVLGJK300/50型,因模型中股线间的接触为强非线性的点、线接触,参考相关有限元建模文献,很难找到理想的方法得到成功的有限元模型。针对这个难点,经过加大股线尺寸6～10个丝,改善原有的有限元模型,并对其进行模态仿真。模态仿真结果较之前的模型更优,更贴近实际。模态仿真结果显示,扩径导线在工程使用中的模态振型,主要以弯扭变形模态为主。当模型长度较短时,发生微风振动的几率较高,导线长度逐渐增加,次档距震荡会凸显,若无间隔棒,导线长度再逐渐增加时,则具有破坏性质的舞动随之而来,这与工程实际运行情况相符。     

750 kV LGJK300/50型高压扩径导线和220 kV LGJ300/25型普通导线静态分析比较

750 kV超高压导线满足“新西电东输”工程的基本电压要求,发展前景广阔,而220 kV高压常规导线是城市电网建设的核心电压,可以说二者在高压输电领域具有典型性。对750 kV和220 kV导线的静态拉伸实验和ANSYS Workbench静态仿真进行对比,对比结果显示:750 kV和220 kV静态仿真中最大轴力下,导线在靠近固定端的最里层钢股处及其邻外层、次外层处零星出现应力集中现象,应力集中不明显,对导线来说,构不成大的威胁。试验中,两导线最外层的一根铝股在夹紧力的作用下还远远未达到导线拉断时的载荷时就已断裂。二者比较后的应力应变误差控制在11%～20%左右,且750 kV导线的抗拉性能优于220 kV导线,具有一定的参考价值。     

Improved Double-Probe Technique for Spatially Resolved Diagnosis of Dual-Frequency Capacitive Plasmas

The conventional double-probe technique was improved with a combination of selfpowering and radio-frequency(RF) choking.RF perturbations in dual-frequency capacitively coupled discharge were effectively eliminated,as judged by the disappearance of self-bias on the probes.The improved technique was tested by spatially resolved measurements of the electron temperature and ion density in both the axial and radial directions of a dual-frequency capacitive plasma.The measured data in the axial direction were compared with simulation results,and they were excellently consistent with each other.The measured radial distributions of the ion density and electron temperature were influenced significantly by the lower frequency(LF) power.It was shown that superposition of the lower frequency to the higher frequency(HF) power shifted the maximum ion density from the radial center to the edge region,while the trend for the electron temperature profile was the opposite.The changing feature of the ion density distribution is qualitatively consistent with that of the optical emission intensity reported.