期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
电磁流动成像测井频率特性分析 被引量:1
1
作者 王晓星 吴锡令 《西南石油大学学报(自然科学版)》 CAS CSCD 北大核心 2009年第4期38-41,共4页
电磁流动成像测井基于油气水导电和介电特性差异测量并重建流体流动的截面图像,其交流激励信号的工作频率对测量的影响主要体现在对混合流体电性(包括电导率和介电常数)以及测量值两个方面。通过理论研究和数值模拟,对频率选取进行讨论... 电磁流动成像测井基于油气水导电和介电特性差异测量并重建流体流动的截面图像,其交流激励信号的工作频率对测量的影响主要体现在对混合流体电性(包括电导率和介电常数)以及测量值两个方面。通过理论研究和数值模拟,对频率选取进行讨论。分析及计算结果表明,根据流型不同,测量频率选择应略有差异,但基本集中在10kHz~10MHz,此时油气水混合流体的各相电性参数保持稳定且差别大,同时各电极模拟测量值基本保持稳定,实部及虚部均差别明显,传感器可以获得最高灵敏度。频率特性分析为实际测量优选交流信号频率提供依据。 展开更多
关键词 多相流 成像测井 频率特性 电性参数 模拟测量值
在线阅读 下载PDF
Dual transponder ranging performance in the presence of oscillator phase noise 被引量:1
2
作者 赵明臣 王春晖 +1 位作者 金小军 金仲和 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1350-1357,共8页
A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscil... A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscillator phase noise, which is the main error source for microwave ranging systems, can be significantly attenuated. Further, since the range measurements are derived on the same satellite, the dual transponder ranging system does not need a time tagging system to synchronize the two satellites. In view of the lack of oscillator noise analysis on the dual transponder ranging model, a comprehensive analysis of oscillator noise effects on ranging accuracy is provided. First, the dual transponder ranging system is described with emphasis on the detailed analysis of oscillator noise on measurement precision. Then, a high-fidelity numerical simulation approach based on the power spectrum density of an actual ultra-stable oscillator is carried out in both frequency domain and time domain to support the presented theoretical analysis. The simulation results under different conditions are consistent with the proposed concepts, which makes the results reliable. Besides, the results demonstrate that a high level of accuracy can be achieved by using this oscillator noise cancelation-oriented ranging method. 展开更多
关键词 inter-satellite carrier ranging oscillator phase noise power spectral density high precision
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部