In view of the inconsistency of channel gains and a large amount of interference noise in Solar Broadband Radio Spectrometer(SBRS) observation data,they will seriously affect the analysis of SBRS data.In this paper,a ...In view of the inconsistency of channel gains and a large amount of interference noise in Solar Broadband Radio Spectrometer(SBRS) observation data,they will seriously affect the analysis of SBRS data.In this paper,a method of Radio Frequency Interference(RFI) detection and mitigation for SBRS observation data is reported.Firstly,the SBRS observation data are preprocessed,a part of the observation data was selected to calculate the mean and variance to achieve the normalization of the entire observation data,which can avoid the influence of strong noise on the normalization result.Furthermore,we proposed an adaptive threshold RFI detection method based on fusion wavelet transform reconstruction and an RFI elimination method based on neighborhood weighted filling.It is worth mentioning that to detect RFI interference signals of different magnitudes,we adopted an iterative approach to the RFI detection and mitigation process.Through qualitative analysis of real observation data and quantitative analysis of simulated data,it is shown that the method proposed in this paper can effectively eliminate RFI in SBRS observation data,and improve the quality of observation data for further scientific analysis.展开更多
We present our state-of-the-art version of a frequency comb for calibration of astronomical spectrographs. The mode spacing of the frequency comb can be designed to match the resolution of a spectrograph. Combined wit...We present our state-of-the-art version of a frequency comb for calibration of astronomical spectrographs. The mode spacing of the frequency comb can be designed to match the resolution of a spectrograph. Combined with its excellent accuracy and stability, the spectral coverage of more than 70% of the whole visible spectrum range makes the frequency comb an ideal calibration source. In addition, the new version introduces the automatic start-up function that brings convenience to the astronomers.展开更多
The study has assessed the denitrification performance of fermented and dark-fermented biosolids as external carbon sources using lab-scaled Sequencing Batch Reactors （SBRs）. This was done by adding fermented and da...The study has assessed the denitrification performance of fermented and dark-fermented biosolids as external carbon sources using lab-scaled Sequencing Batch Reactors （SBRs）. This was done by adding fermented and dark-fermented biosolids into anoxic zones of two SBRs, and then assessing the change of effluent characteristics comparing to before adding and to a third controlled reactor. The results showed that by adding 150-170 mg rbCOD/L of either of the selected fermented biosolids, almost complete denitrification could be reached for tested SBRs （reduced from initial -20 mg NO3/L to 〈 1 mg NO3/L）. Finally, the experiment also found that the impact of NI-I4 components of fermented and dark-fermented biosolids onto the final effluent were much lesser than expected, where only less than 2.5 mg NH4/L were detected in the effluent, much lower than the added 5.0-5.7 mg/L.展开更多
The aim of this study was to assess the impact of industrial-grade sucrose as external carbon source on post-anoxic denitrification. This was done through the use of lab-scaled Sequencing Batch Reactors （SBRs） model...The aim of this study was to assess the impact of industrial-grade sucrose as external carbon source on post-anoxic denitrification. This was done through the use of lab-scaled Sequencing Batch Reactors （SBRs） modelling after a standard post-anoxic Waste Water Treatment Plant （WWTP）. Each reactor holds an effective volume of approximately 4 L, with the decant volume of 2 L per cycle, a Hydraulic Retention Time （HRT） of 8 hours, Sludge Retention Time （SRT） of about 11.5 ± 0.5 days. The experiments showed that adding industrial-grade sucrose into the post-anoxic zone has a very significant improvement where the nitrate removal rate increased from 10% to 68%. The experiment also verifies that most of the Specific Denitrification Rate （SDNR） calculated from the lab-scaled SBRs lie within the range of earlier study （2.29-2.85 mgNO3/gMLVSS/h）, and verified the results of both this experiment and the SDNR batch tests in previous study.展开更多
基金funded by the Open Research Program of CAS Key Laboratory of Solar Activity,National Astronomical Observatories (KLSA201909)the National Natural Science Foundation of China (Nos.11773072 and 11873027)Yunnan Fundamental Research Projects (202001AT070135)。
文摘In view of the inconsistency of channel gains and a large amount of interference noise in Solar Broadband Radio Spectrometer(SBRS) observation data,they will seriously affect the analysis of SBRS data.In this paper,a method of Radio Frequency Interference(RFI) detection and mitigation for SBRS observation data is reported.Firstly,the SBRS observation data are preprocessed,a part of the observation data was selected to calculate the mean and variance to achieve the normalization of the entire observation data,which can avoid the influence of strong noise on the normalization result.Furthermore,we proposed an adaptive threshold RFI detection method based on fusion wavelet transform reconstruction and an RFI elimination method based on neighborhood weighted filling.It is worth mentioning that to detect RFI interference signals of different magnitudes,we adopted an iterative approach to the RFI detection and mitigation process.Through qualitative analysis of real observation data and quantitative analysis of simulated data,it is shown that the method proposed in this paper can effectively eliminate RFI in SBRS observation data,and improve the quality of observation data for further scientific analysis.
文摘We present our state-of-the-art version of a frequency comb for calibration of astronomical spectrographs. The mode spacing of the frequency comb can be designed to match the resolution of a spectrograph. Combined with its excellent accuracy and stability, the spectral coverage of more than 70% of the whole visible spectrum range makes the frequency comb an ideal calibration source. In addition, the new version introduces the automatic start-up function that brings convenience to the astronomers.
文摘The study has assessed the denitrification performance of fermented and dark-fermented biosolids as external carbon sources using lab-scaled Sequencing Batch Reactors （SBRs）. This was done by adding fermented and dark-fermented biosolids into anoxic zones of two SBRs, and then assessing the change of effluent characteristics comparing to before adding and to a third controlled reactor. The results showed that by adding 150-170 mg rbCOD/L of either of the selected fermented biosolids, almost complete denitrification could be reached for tested SBRs （reduced from initial -20 mg NO3/L to 〈 1 mg NO3/L）. Finally, the experiment also found that the impact of NI-I4 components of fermented and dark-fermented biosolids onto the final effluent were much lesser than expected, where only less than 2.5 mg NH4/L were detected in the effluent, much lower than the added 5.0-5.7 mg/L.
文摘The aim of this study was to assess the impact of industrial-grade sucrose as external carbon source on post-anoxic denitrification. This was done through the use of lab-scaled Sequencing Batch Reactors （SBRs） modelling after a standard post-anoxic Waste Water Treatment Plant （WWTP）. Each reactor holds an effective volume of approximately 4 L, with the decant volume of 2 L per cycle, a Hydraulic Retention Time （HRT） of 8 hours, Sludge Retention Time （SRT） of about 11.5 ± 0.5 days. The experiments showed that adding industrial-grade sucrose into the post-anoxic zone has a very significant improvement where the nitrate removal rate increased from 10% to 68%. The experiment also verifies that most of the Specific Denitrification Rate （SDNR） calculated from the lab-scaled SBRs lie within the range of earlier study （2.29-2.85 mgNO3/gMLVSS/h）, and verified the results of both this experiment and the SDNR batch tests in previous study.
