An easy and practical system of feeble fluctuation of liquid electrical conductivity is described. The system, which increases a precision on the three orders magnitude as compared with that of the recent domestic con...An easy and practical system of feeble fluctuation of liquid electrical conductivity is described. The system, which increases a precision on the three orders magnitude as compared with that of the recent domestic conductivity meter, is used to measure the feeble fluctuation of the conductivity by means of compensation and comparison, so that it solves the problem of measuring the feeble fluctuation.展开更多
A new optical fiber fluoroptic thermometer based on the temperature—fluoroptic characteristic of fluoroptic materials is presented.The ratio technique of intensities of fluorescent emission lines of certain rare eart...A new optical fiber fluoroptic thermometer based on the temperature—fluoroptic characteristic of fluoroptic materials is presented.The ratio technique of intensities of fluorescent emission lines of certain rare earth phosphors is used,making the measurement of temperatures of the system to 0.5 ℃ precision. The characteristics of thermometer are discussed and the experiment results of temperature are given.展开更多
Selecting the optimal reference satellite is an important component of high-precision relat/ve positioning because the reference satellite directly influences the strength of the normal equation. The reference satelli...Selecting the optimal reference satellite is an important component of high-precision relat/ve positioning because the reference satellite directly influences the strength of the normal equation. The reference satellite selection methods based on elevation and positional dilution of precision (PDOP) value were compared. Results show that all the above methods cannot select the optimal reference satellite. We introduce condition number of the design matrix in the reference satellite selection method to improve structure of the normal equation, because condition number can indicate the ill condition of the normal equation. The experimental results show that the new method can improve positioning accuracy and reliability in precise relative positioning.展开更多
文摘An easy and practical system of feeble fluctuation of liquid electrical conductivity is described. The system, which increases a precision on the three orders magnitude as compared with that of the recent domestic conductivity meter, is used to measure the feeble fluctuation of the conductivity by means of compensation and comparison, so that it solves the problem of measuring the feeble fluctuation.
文摘A new optical fiber fluoroptic thermometer based on the temperature—fluoroptic characteristic of fluoroptic materials is presented.The ratio technique of intensities of fluorescent emission lines of certain rare earth phosphors is used,making the measurement of temperatures of the system to 0.5 ℃ precision. The characteristics of thermometer are discussed and the experiment results of temperature are given.
基金partially sponsored by the National 973 Project of China(2013CB733303)partially supported by the postgraduate independent exploration project of Central South University(2014zzts249)
文摘Selecting the optimal reference satellite is an important component of high-precision relat/ve positioning because the reference satellite directly influences the strength of the normal equation. The reference satellite selection methods based on elevation and positional dilution of precision (PDOP) value were compared. Results show that all the above methods cannot select the optimal reference satellite. We introduce condition number of the design matrix in the reference satellite selection method to improve structure of the normal equation, because condition number can indicate the ill condition of the normal equation. The experimental results show that the new method can improve positioning accuracy and reliability in precise relative positioning.