The parameters of Earth free core nutation (FCN) are two relatively significant geophysical parameters. Sasao et al. (1980) and Wahr and Bergen (1986) provided the theoretical estimation values of FCN parameters. Gwin...The parameters of Earth free core nutation (FCN) are two relatively significant geophysical parameters. Sasao et al. (1980) and Wahr and Bergen (1986) provided the theoretical estimation values of FCN parameters. Gwinn, Herring and Shapiro (1987) first obtained the observational values of FCN parameters by very long base Interference (VLBI) at Cambridge University. In the same year, Neuberg and Zurn in former West Germany and Hinderer in France began to retrieve FCN parameters by the observation of gravity tides and introduced the stacking method. The other scholars who researched into the same geophysical problems by applying the data of gravity tides basically followed the stacking method. The results they reached were similar to the observational result of FCN parameters given by Neuberg et al. in 1987. But the observational results of FCN parameters gained from gravity tides were not identical with those from VLBI, mainly because of the large difference of quality of FCN. So there was not an affirmative observational result of FCN parameters since then. In this paper, The authors firstly introduce the tri-frequency spectrum method with clearly geometrical and geophysical meaning for the resolution of FCN parameters , and the observational results of FCN parameters obtained from tide data at three superconducting gravity stations were accordant with those from VLBI, which will be relatively important to arriving at a certain observational result of FCN parameters.展开更多
The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the refle...The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the reflectometer.We present a simple method, using cubic spline interpolation to resample the spectrum with a high resolution,to extend the measurable transparent film thickness. A large measuring range up to 385 m in optical thickness is achieved with the commonly used system. The numerical calculation and experimental results demonstrate that using the FFT method combined with cubic spline interpolation resampling in reflectrometry, a simple,easy-to-operate, economic measuring system can be achieved with high measuring accuracy and replicability.展开更多
Nowadays the development of Internet of Things （loT） and defense technologies imperatively needs high-performance photodetectors that can work in a broadband wavelength range, in particular, covering the mid-infrar...Nowadays the development of Internet of Things （loT） and defense technologies imperatively needs high-performance photodetectors that can work in a broadband wavelength range, in particular, covering the mid-infrared （MIR） region [1]. This generates great interest in the incorporation of a series of novel optoelectronic materials and structures into the photodetectors. Graphene and colloidal quantum dots （QDs） are key players among novel materials used to fabricate high-performance photodetectors [2-4]. By taking advantage of the high mobility of graphene and excellent tunable optical absorption of colloidal QDs,展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No.40074018).
文摘The parameters of Earth free core nutation (FCN) are two relatively significant geophysical parameters. Sasao et al. (1980) and Wahr and Bergen (1986) provided the theoretical estimation values of FCN parameters. Gwinn, Herring and Shapiro (1987) first obtained the observational values of FCN parameters by very long base Interference (VLBI) at Cambridge University. In the same year, Neuberg and Zurn in former West Germany and Hinderer in France began to retrieve FCN parameters by the observation of gravity tides and introduced the stacking method. The other scholars who researched into the same geophysical problems by applying the data of gravity tides basically followed the stacking method. The results they reached were similar to the observational result of FCN parameters given by Neuberg et al. in 1987. But the observational results of FCN parameters gained from gravity tides were not identical with those from VLBI, mainly because of the large difference of quality of FCN. So there was not an affirmative observational result of FCN parameters since then. In this paper, The authors firstly introduce the tri-frequency spectrum method with clearly geometrical and geophysical meaning for the resolution of FCN parameters , and the observational results of FCN parameters obtained from tide data at three superconducting gravity stations were accordant with those from VLBI, which will be relatively important to arriving at a certain observational result of FCN parameters.
基金Supported by the National Natural Science Foundation of China under Grant No 11604115the Educational Commission of Jiangsu Province of China under Grant No 17KJA460004the Huaian Science and Technology Funds under Grant No HAC201701
文摘The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the reflectometer.We present a simple method, using cubic spline interpolation to resample the spectrum with a high resolution,to extend the measurable transparent film thickness. A large measuring range up to 385 m in optical thickness is achieved with the commonly used system. The numerical calculation and experimental results demonstrate that using the FFT method combined with cubic spline interpolation resampling in reflectrometry, a simple,easy-to-operate, economic measuring system can be achieved with high measuring accuracy and replicability.
文摘Nowadays the development of Internet of Things （loT） and defense technologies imperatively needs high-performance photodetectors that can work in a broadband wavelength range, in particular, covering the mid-infrared （MIR） region [1]. This generates great interest in the incorporation of a series of novel optoelectronic materials and structures into the photodetectors. Graphene and colloidal quantum dots （QDs） are key players among novel materials used to fabricate high-performance photodetectors [2-4]. By taking advantage of the high mobility of graphene and excellent tunable optical absorption of colloidal QDs,
