A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the rel...A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the relatively simple configuration and optics were employed to measure the steel samples at a remote distance and a hot sample temperature. The system has obtained a robustness for the deviation of the sample position because of the open-path and alloptical structure. The measurement was carried out at different sample temperatures by placing the samples in a muffle furnace with a window in the front door. The results show that the intensity of the spectral lines increased as the sample temperature increased. The influence of the sample temperature on the quantitative analysis of manganese in the steel samples was investigated by measuring ten standard steel samples at different temperatures. Three samples were selected as the test sample for the simulation measurement. The results show that, at the sample temperature of 500 ℃, the average relative error of prediction is 3.1% and the average relative standard deviation is 7.7%, respectively.展开更多
基于2003—2022年中国知网(CNKI)和Web of Science期刊数据库的文献源,通过可视化分析工具Citespace对国内外“开放式创新”为主题的学术论文进行计量分析。据此发现和解读出该领域的四大研究热点:开放式创新与企业创新绩效的关系研究...基于2003—2022年中国知网(CNKI)和Web of Science期刊数据库的文献源,通过可视化分析工具Citespace对国内外“开放式创新”为主题的学术论文进行计量分析。据此发现和解读出该领域的四大研究热点:开放式创新与企业创新绩效的关系研究、开放式创新中的知识产权治理研究、开放式创新背景下的商业模式变革、开放式创新背景下的创新网络研究。未来研究仍需深化开放式创新基本理论研究、聚焦微观视角、拓宽研究主题、着眼战略角度。展开更多
For flux measurement, the eddy covariance technique supplies a possibility to directly measure the exchange between vegetation and atmosphere; and there are two kinds of eddy covariance systems, open-path and close-pa...For flux measurement, the eddy covariance technique supplies a possibility to directly measure the exchange between vegetation and atmosphere; and there are two kinds of eddy covariance systems, open-path and close-path systems. For the system error, it may result in difference of flux measurements by two systems. Therefore, it is necessary to compare the measured results from them. ChinaFLUX covers of eight sites applied the micrometeorological method, in which Changbai Mountains (CBS) and Qianyanzhou (QYZ) carried out open-path eddy covariance (OPEC) and close-path eddy covariance (CPEC) measurements synchronously. In this paper the data sets of CBS and QYZ were employed. The delay time of close-path analyzer to the open-path analyzer was calculated; the spectra and cospectra of time-series data of OPEC and CPEC were analyzed; the open-path flux measurement was used as a standard comparison, the close-path flux measurement results were evaluated. The results show that, at two sites the delay time of CO2 density for close-path analyzer was about 7.0-8.0 s, H2O density about 8.0-9.0 s; the spectrum from the open-path, close-path and 3D sonic anemometer was consistent with the expected -2/3 slope (log-log plot), and the cospectra showed the expected slope of -4/3 in the internal subrange; the CO? flux measured by the close-path sensor was about 84% of that of open-path measurement at QYZ, about 80% at CBS, and the latent heat flux was balanced for two systems at QYZ, 86% at CBS. From the flux difference between open-path and close-path analyzers, it could be inferred that the attenuation of turbulent fluctuations in flow through tube of CPEC affected H2O flux more significantly than CO2 flux. The gap between two systems was bigger at CBS than at QYZ; the diurnal variation in CO2 flux of two measurement systems was very consistent.展开更多
基金supported by National Natural Science Foundation of China (Nos. 51506171 and 51675415)National Natural Science Foundation of China for Key Program (No. 51335009)+1 种基金National Key Research and Development Program of China (No. 2017YFD0700200)the joint research fund between Tokushima University and Xi’an Jiaotong University
文摘A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the relatively simple configuration and optics were employed to measure the steel samples at a remote distance and a hot sample temperature. The system has obtained a robustness for the deviation of the sample position because of the open-path and alloptical structure. The measurement was carried out at different sample temperatures by placing the samples in a muffle furnace with a window in the front door. The results show that the intensity of the spectral lines increased as the sample temperature increased. The influence of the sample temperature on the quantitative analysis of manganese in the steel samples was investigated by measuring ten standard steel samples at different temperatures. Three samples were selected as the test sample for the simulation measurement. The results show that, at the sample temperature of 500 ℃, the average relative error of prediction is 3.1% and the average relative standard deviation is 7.7%, respectively.
文摘基于2003—2022年中国知网(CNKI)和Web of Science期刊数据库的文献源,通过可视化分析工具Citespace对国内外“开放式创新”为主题的学术论文进行计量分析。据此发现和解读出该领域的四大研究热点:开放式创新与企业创新绩效的关系研究、开放式创新中的知识产权治理研究、开放式创新背景下的商业模式变革、开放式创新背景下的创新网络研究。未来研究仍需深化开放式创新基本理论研究、聚焦微观视角、拓宽研究主题、着眼战略角度。
文摘For flux measurement, the eddy covariance technique supplies a possibility to directly measure the exchange between vegetation and atmosphere; and there are two kinds of eddy covariance systems, open-path and close-path systems. For the system error, it may result in difference of flux measurements by two systems. Therefore, it is necessary to compare the measured results from them. ChinaFLUX covers of eight sites applied the micrometeorological method, in which Changbai Mountains (CBS) and Qianyanzhou (QYZ) carried out open-path eddy covariance (OPEC) and close-path eddy covariance (CPEC) measurements synchronously. In this paper the data sets of CBS and QYZ were employed. The delay time of close-path analyzer to the open-path analyzer was calculated; the spectra and cospectra of time-series data of OPEC and CPEC were analyzed; the open-path flux measurement was used as a standard comparison, the close-path flux measurement results were evaluated. The results show that, at two sites the delay time of CO2 density for close-path analyzer was about 7.0-8.0 s, H2O density about 8.0-9.0 s; the spectrum from the open-path, close-path and 3D sonic anemometer was consistent with the expected -2/3 slope (log-log plot), and the cospectra showed the expected slope of -4/3 in the internal subrange; the CO? flux measured by the close-path sensor was about 84% of that of open-path measurement at QYZ, about 80% at CBS, and the latent heat flux was balanced for two systems at QYZ, 86% at CBS. From the flux difference between open-path and close-path analyzers, it could be inferred that the attenuation of turbulent fluctuations in flow through tube of CPEC affected H2O flux more significantly than CO2 flux. The gap between two systems was bigger at CBS than at QYZ; the diurnal variation in CO2 flux of two measurement systems was very consistent.
