基于双混频时差技术设计研制了8通道的频率稳定度测量系统,实现了对8路5 MHz或10 MHz频率标准的测量.当频率为10 MHz取样时间为1 s时,系统噪声本底优于2.0 X 10^(-13),取样时间为1000 s时,系统噪声本底优于2.5×10^(-16).不但可以...基于双混频时差技术设计研制了8通道的频率稳定度测量系统,实现了对8路5 MHz或10 MHz频率标准的测量.当频率为10 MHz取样时间为1 s时,系统噪声本底优于2.0 X 10^(-13),取样时间为1000 s时,系统噪声本底优于2.5×10^(-16).不但可以满足原子时标基准原子钟组的内部比对,也可实现对一般频率标准的检定和校准.
Abstract：
Based on the technique of Dual Mixer Time Difference (DMTD), an 8-channel frequency stabilitymeasurement system has been developed. It realized the measurement of 8-channel 5 MHz and 10 MHz frequencystandards. For 10 MHz frequency, the noise floor is better than 2.0 ×10^(-13)/1 s, 2.5× 10^(-16)/1000 s. It can not only satisfy the internal comparison of time scale ensemble, but also can realize the calibration of normal frequency standards.展开更多
In order to study discrete nonconservative system,Hamilton's principle within fractional difference operators of Riemann-Liouville type is given. Discrete Lagrange equations of the nonconservative system as well a...In order to study discrete nonconservative system,Hamilton's principle within fractional difference operators of Riemann-Liouville type is given. Discrete Lagrange equations of the nonconservative system as well as the nonconservative system with dynamic constraint are established within fractional difference operators of Riemann-Liouville type from the view of time scales. Firstly,time scale calculus and fractional calculus are reviewed.Secondly,with the help of the properties of time scale calculus,discrete Lagrange equation of the nonconservative system within fractional difference operators of Riemann-Liouville type is presented. Thirdly,using the Lagrange multipliers,discrete Lagrange equation of the nonconservative system with dynamic constraint is also established.Then two special cases are discussed. Finally,two examples are devoted to illustrate the results.展开更多
文摘基于双混频时差技术设计研制了8通道的频率稳定度测量系统,实现了对8路5 MHz或10 MHz频率标准的测量.当频率为10 MHz取样时间为1 s时,系统噪声本底优于2.0 X 10^(-13),取样时间为1000 s时,系统噪声本底优于2.5×10^(-16).不但可以满足原子时标基准原子钟组的内部比对,也可实现对一般频率标准的检定和校准.
Abstract：
Based on the technique of Dual Mixer Time Difference (DMTD), an 8-channel frequency stabilitymeasurement system has been developed. It realized the measurement of 8-channel 5 MHz and 10 MHz frequencystandards. For 10 MHz frequency, the noise floor is better than 2.0 ×10^(-13)/1 s, 2.5× 10^(-16)/1000 s. It can not only satisfy the internal comparison of time scale ensemble, but also can realize the calibration of normal frequency standards.
基金supported by the National Natural Science Foundation of China(Nos.11802193, 11572212,11272227)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (18KJB130005)+1 种基金the Science Research Foundation of Suzhou University of Science and Technology(331812137)Natural Science Foundation of Suzhou University of Science and Technology
文摘In order to study discrete nonconservative system,Hamilton's principle within fractional difference operators of Riemann-Liouville type is given. Discrete Lagrange equations of the nonconservative system as well as the nonconservative system with dynamic constraint are established within fractional difference operators of Riemann-Liouville type from the view of time scales. Firstly,time scale calculus and fractional calculus are reviewed.Secondly,with the help of the properties of time scale calculus,discrete Lagrange equation of the nonconservative system within fractional difference operators of Riemann-Liouville type is presented. Thirdly,using the Lagrange multipliers,discrete Lagrange equation of the nonconservative system with dynamic constraint is also established.Then two special cases are discussed. Finally,two examples are devoted to illustrate the results.
