Silicon isotope analysis traditionally uses a standard-sample bracketing （SSB） method that relies upon greater instrument stability than can be consistently expected. The following proposed method reduces the level ...Silicon isotope analysis traditionally uses a standard-sample bracketing （SSB） method that relies upon greater instrument stability than can be consistently expected. The following proposed method reduces the level of instrumental stability required for the analysis process and provides a valid solution for high-precision and accurate studies of Si isotopic compositions. Rock samples were dissolved by using alkali fusion and acidification. Silicon isotopes were purified with an ion exchange resin. Interfering peaks for isotopes were separated by using a Nu Plasma 1700 multi-collector inductively coupled plasma mass spectrometry （MS） system in high-resolution mode （M/AM 〉 8000 RP）. Two magnesium isotopes （25Mg and 26Mg） and three silicon isotopes （28Si, 29Si, and 3;Si） were analyzed in the same data collection cycle. Mg isotopes were used as an internal standard to calibrate the mass discrimination effects in MS analysis of Si isotopes in combination with the SSB method in order to reduce the effects of MS interference and instrumental mass dis- crimination on the accuracy of measurements. The conventional SSB method without the Mg internal standard and the proposed SSB method with Mg calibration delivered consistent results within two standard deviations. When Mg was used as an internal standard for calibration, the analysis precision was better than 0.05 %0 amu.展开更多
This paper introduces the design and development of a new computerized data acquisition system for the coal fired magnetohydrodynamical (MHD) electrical power generation experiments. Compared to the previous system, ...This paper introduces the design and development of a new computerized data acquisition system for the coal fired magnetohydrodynamical (MHD) electrical power generation experiments. Compared to the previous system, it has a higher sampling rate and an improved simultaneity performance. It also improves the data collection method and sensor design for the measurement of Faraday voltages and Faraday currents. The system has been successfully used in many regular MHD generator tests. It provides an excellent base for the future research and development of the Coal fired MHD electrical power generation.展开更多
This paper presents main functions of a high voltage,high speed and extensive memory transient measurementequipment and design of associate hardware and software. Thepaper also introduces the hardware design of high s...This paper presents main functions of a high voltage,high speed and extensive memory transient measurementequipment and design of associate hardware and software. Thepaper also introduces the hardware design of high speed hugememory data sampler, explains the know-how of data analysissoftware, program-controlled voltage divider andanti-interference measurement, with which the equipmentperforms excellent on--site.This equipment reallies automatic measurement and satisfiesthe requirement of high voltage digital measurment.展开更多
基金funded by the National Natural Science Foundation of China(Grant Nos.41427804,41421002,41373004)Beijing SHRIMP Center Open Foundation,and Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT1281)the MOST Research Foundation from the State Key Laboratory of Continental Dynamics(BJ08132-1)
文摘Silicon isotope analysis traditionally uses a standard-sample bracketing （SSB） method that relies upon greater instrument stability than can be consistently expected. The following proposed method reduces the level of instrumental stability required for the analysis process and provides a valid solution for high-precision and accurate studies of Si isotopic compositions. Rock samples were dissolved by using alkali fusion and acidification. Silicon isotopes were purified with an ion exchange resin. Interfering peaks for isotopes were separated by using a Nu Plasma 1700 multi-collector inductively coupled plasma mass spectrometry （MS） system in high-resolution mode （M/AM 〉 8000 RP）. Two magnesium isotopes （25Mg and 26Mg） and three silicon isotopes （28Si, 29Si, and 3;Si） were analyzed in the same data collection cycle. Mg isotopes were used as an internal standard to calibrate the mass discrimination effects in MS analysis of Si isotopes in combination with the SSB method in order to reduce the effects of MS interference and instrumental mass dis- crimination on the accuracy of measurements. The conventional SSB method without the Mg internal standard and the proposed SSB method with Mg calibration delivered consistent results within two standard deviations. When Mg was used as an internal standard for calibration, the analysis precision was better than 0.05 %0 amu.
文摘This paper introduces the design and development of a new computerized data acquisition system for the coal fired magnetohydrodynamical (MHD) electrical power generation experiments. Compared to the previous system, it has a higher sampling rate and an improved simultaneity performance. It also improves the data collection method and sensor design for the measurement of Faraday voltages and Faraday currents. The system has been successfully used in many regular MHD generator tests. It provides an excellent base for the future research and development of the Coal fired MHD electrical power generation.
文摘This paper presents main functions of a high voltage,high speed and extensive memory transient measurementequipment and design of associate hardware and software. Thepaper also introduces the hardware design of high speed hugememory data sampler, explains the know-how of data analysissoftware, program-controlled voltage divider andanti-interference measurement, with which the equipmentperforms excellent on--site.This equipment reallies automatic measurement and satisfiesthe requirement of high voltage digital measurment.
