In this paper,we are interested in HSS preconditioners for saddle point lin- ear systems with a nonzero(2,2)-th block.We study an approximation of the spectra of HSS preconditioned matrices and use these results to il...In this paper,we are interested in HSS preconditioners for saddle point lin- ear systems with a nonzero(2,2)-th block.We study an approximation of the spectra of HSS preconditioned matrices and use these results to illustrate and explain the spectra obtained from numerical examples,where the previous spectral analysis of HSS precon- ditioned matrices does not cover.展开更多
N-FINDR is a very popular algorithm of endmember (EM) extraction for its automated property and high efficiency. Unfortunately, innumerable volume calculation, initial random selection of EMs and blind searching for E...N-FINDR is a very popular algorithm of endmember (EM) extraction for its automated property and high efficiency. Unfortunately, innumerable volume calculation, initial random selection of EMs and blind searching for EMs lead to low speed of the algorithm and limit the applications of the algorithm. So in this paper two measures are proposed to speed up the algorithm. One of the measures is substituting distance calculation for volume calculation. Thus the avoidance of volume calculation greatly decreases the computational cost. The other measure is resorting dataset in terms of pixel purity likelihood based on pixel purity index (PPI) concept. Then, initial EMs can be selected well-founded and a fast searching for EMs is achieved. Numerical experiments show that the two measures speed up the original algorithm hundreds of times as the number of EMs is more than ten.展开更多
Detection of a periodic signal hidden in noise is the goal of Superconducting Gravimeter (SG) data analysis. Due to spikes, gaps, datum shrifts (offsets) and other disturbances, the traditional FFT method shows inhere...Detection of a periodic signal hidden in noise is the goal of Superconducting Gravimeter (SG) data analysis. Due to spikes, gaps, datum shrifts (offsets) and other disturbances, the traditional FFT method shows inherent limitations. Instead, the least squares spectral analysis (LSSA) has showed itself more suitable than Fourier analysis of gappy, unequally spaced and unequally weighted data series in a variety of applications in geodesy and geophysics. This paper reviews the principle of LSSA and gives a possible strategy for the analysis of time series obtained from the Canadian Superconducting Gravimeter Installation (CGSI), with gaps, offsets, unequal sampling decimation of the data and unequally weighted data points.展开更多
In order to combine feature extraction operations with specific hyperspectral remote sensing information processing objectives,two aspects of feature extraction were explored. Based on clustering and decision tree alg...In order to combine feature extraction operations with specific hyperspectral remote sensing information processing objectives,two aspects of feature extraction were explored. Based on clustering and decision tree algorithm,spectral absorption index (SAI),continuum-removal and derivative spectral analysis were employed to discover characterized spectral features of different targets,and decision trees for identifying a specific class and discriminating different classes were generated. By combining support vector machine (SVM) classifier with different feature extraction strategies including principal component analysis (PCA),minimum noise fraction (MNF),grouping PCA,and derivate spectral analysis,the performance of feature extraction approaches in classification was evaluated. The results show that feature extraction by PCA and derivate spectral analysis are effective to OMIS (operational modular imaging spectrometer) image classification using SVM,and SVM outperforms traditional SAM and MLC classifiers for OMIS data.展开更多
The FAs （fulvic acids） belong to natural organic contaminants that are commonly found in different environments. In the process of oxidation and disinfection FAs are precursors of toxic substances, which cause a pro...The FAs （fulvic acids） belong to natural organic contaminants that are commonly found in different environments. In the process of oxidation and disinfection FAs are precursors of toxic substances, which cause a problem in many water treatment plants. In the sewage treatment plants, FAs are not biodegradable and together with purified wastewater and are discharged into surface waters. One of important source of the formation of FAs is the municipal landfill. In this thesis the authors test the amount of soluble fulvic acids present in the leachate of Barycz landfill in Krakow. The extracted FAs were subjected to a detailed analysis for the content of metals and IR spectrum analysis has also been done. Basing on elemental composition the C/O, C/H and C/N ratios have been determined. The obtained data were compared with the characteristics specified in the literature.展开更多
The structure of the acousto-optic spectrum analyzer was investigated including the RF amplifying circuit, the optical structures and the postprocessing circuit, and the design idea of the module was applied to design...The structure of the acousto-optic spectrum analyzer was investigated including the RF amplifying circuit, the optical structures and the postprocessing circuit, and the design idea of the module was applied to design the spectrum analyzer. The modularization spectrum analyzer takes on the performance stabilization and higher reliability, and according to different demands, the different modules can be used. The spectrum analyzer had such performances as the detecting frequency precision of 1 MHz, the detecting frequency error of 0.58 MHz, detecting responsivity of 90 dBm and bandwidth of 50 MHz.展开更多
This paper studied on the removal of toxic substance from river water using O3-GAC process. The result of GC/MS analysis indicated that the number of organic compound species was decreased by 55.1%. The species of tox...This paper studied on the removal of toxic substance from river water using O3-GAC process. The result of GC/MS analysis indicated that the number of organic compound species was decreased by 55.1%. The species of toxic substance of raw water also decreased from 16 to 5. The total removal rate of CODMn andUV254 were 45%～72% and 60%～80% following O3-GAC treatment. It reflected that this process had a good effective on removing unsaturation organic which absorb UV and toxic organic containing nitrogen. The results of Ames test indicated that raw water had a relatively strong mutagicity on TA 98. The O3-GAC process had a good ability in removing mutagen in water. The effluent water’s mutagicity is minus. The results of the study indicated that the effluent of the O3-GAC process was meet the demand of drinking water.展开更多
As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more effici...As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol(DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane(R134a) extraction in combination with gas chromatography-mass spectrometry(GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C_(18) and NH_2 solid phase extraction(SPE). Finally, the analyte was derived by heptafluorobutyric anhydride(HFBA), followed by GC-MS analysis. Response surface methodology(RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26℃; amount of co-solvent volume, 4.7 m L. Under this condition, at a spiked level of 1, 5, 10 μg kg^(-1), the mean recovery of DES was more than 90% with relative standard deviations(RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.展开更多
The basics and applications of acousto-optic devices are described.The applications include acousto-optic spectrum analyzer,acousto-optic deflector,acousto-optic processors and acousto-optic digital matrix computer.
Fourier transform infrared attenuated total reflectance （FTIR-ATR） spectroscopy was employed to characterize rapeseed oils. The spectral features of rapeseed oils were first investigated. Spectral data was processed...Fourier transform infrared attenuated total reflectance （FTIR-ATR） spectroscopy was employed to characterize rapeseed oils. The spectral features of rapeseed oils were first investigated. Spectral data was processed using principal component analysis （PCA） and linear discriminant analysis （LDA） to discriminate the oils from three cultivars of rapeseeds. As a result, 100% discrimination accuracy was obtained by LDA. Furthermore, the applicability of FTIR-ATR spectroscopy to characterize the changes of rapeseed oils caused by thermal treatment was studied. The rapeseed oil at 60 ℃ was regularly subjected to spectral measurement, and the spectral changes induced by thermal treatment were analyzed and discussed. This study had demonstrated the good performance of FTIR-ATR spectroscopy in characterizing rapeseed oils.展开更多
文摘In this paper,we are interested in HSS preconditioners for saddle point lin- ear systems with a nonzero(2,2)-th block.We study an approximation of the spectra of HSS preconditioned matrices and use these results to illustrate and explain the spectra obtained from numerical examples,where the previous spectral analysis of HSS precon- ditioned matrices does not cover.
基金Sponsored by the National Natural Science Foundation of China (Grant No 60402025 and 60302019)
文摘N-FINDR is a very popular algorithm of endmember (EM) extraction for its automated property and high efficiency. Unfortunately, innumerable volume calculation, initial random selection of EMs and blind searching for EMs lead to low speed of the algorithm and limit the applications of the algorithm. So in this paper two measures are proposed to speed up the algorithm. One of the measures is substituting distance calculation for volume calculation. Thus the avoidance of volume calculation greatly decreases the computational cost. The other measure is resorting dataset in terms of pixel purity likelihood based on pixel purity index (PPI) concept. Then, initial EMs can be selected well-founded and a fast searching for EMs is achieved. Numerical experiments show that the two measures speed up the original algorithm hundreds of times as the number of EMs is more than ten.
文摘Detection of a periodic signal hidden in noise is the goal of Superconducting Gravimeter (SG) data analysis. Due to spikes, gaps, datum shrifts (offsets) and other disturbances, the traditional FFT method shows inherent limitations. Instead, the least squares spectral analysis (LSSA) has showed itself more suitable than Fourier analysis of gappy, unequally spaced and unequally weighted data series in a variety of applications in geodesy and geophysics. This paper reviews the principle of LSSA and gives a possible strategy for the analysis of time series obtained from the Canadian Superconducting Gravimeter Installation (CGSI), with gaps, offsets, unequal sampling decimation of the data and unequally weighted data points.
基金Projects 40401038 and 40871195 supported by the National Natural Science Foundation of ChinaNCET-06-0476 by the Program for New Century Excellent Talents in University20070290516 by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘In order to combine feature extraction operations with specific hyperspectral remote sensing information processing objectives,two aspects of feature extraction were explored. Based on clustering and decision tree algorithm,spectral absorption index (SAI),continuum-removal and derivative spectral analysis were employed to discover characterized spectral features of different targets,and decision trees for identifying a specific class and discriminating different classes were generated. By combining support vector machine (SVM) classifier with different feature extraction strategies including principal component analysis (PCA),minimum noise fraction (MNF),grouping PCA,and derivate spectral analysis,the performance of feature extraction approaches in classification was evaluated. The results show that feature extraction by PCA and derivate spectral analysis are effective to OMIS (operational modular imaging spectrometer) image classification using SVM,and SVM outperforms traditional SAM and MLC classifiers for OMIS data.
文摘The FAs （fulvic acids） belong to natural organic contaminants that are commonly found in different environments. In the process of oxidation and disinfection FAs are precursors of toxic substances, which cause a problem in many water treatment plants. In the sewage treatment plants, FAs are not biodegradable and together with purified wastewater and are discharged into surface waters. One of important source of the formation of FAs is the municipal landfill. In this thesis the authors test the amount of soluble fulvic acids present in the leachate of Barycz landfill in Krakow. The extracted FAs were subjected to a detailed analysis for the content of metals and IR spectrum analysis has also been done. Basing on elemental composition the C/O, C/H and C/N ratios have been determined. The obtained data were compared with the characteristics specified in the literature.
文摘The structure of the acousto-optic spectrum analyzer was investigated including the RF amplifying circuit, the optical structures and the postprocessing circuit, and the design idea of the module was applied to design the spectrum analyzer. The modularization spectrum analyzer takes on the performance stabilization and higher reliability, and according to different demands, the different modules can be used. The spectrum analyzer had such performances as the detecting frequency precision of 1 MHz, the detecting frequency error of 0.58 MHz, detecting responsivity of 90 dBm and bandwidth of 50 MHz.
文摘This paper studied on the removal of toxic substance from river water using O3-GAC process. The result of GC/MS analysis indicated that the number of organic compound species was decreased by 55.1%. The species of toxic substance of raw water also decreased from 16 to 5. The total removal rate of CODMn andUV254 were 45%～72% and 60%～80% following O3-GAC treatment. It reflected that this process had a good effective on removing unsaturation organic which absorb UV and toxic organic containing nitrogen. The results of Ames test indicated that raw water had a relatively strong mutagicity on TA 98. The O3-GAC process had a good ability in removing mutagen in water. The effluent water’s mutagicity is minus. The results of the study indicated that the effluent of the O3-GAC process was meet the demand of drinking water.
基金supported by the National Natural Science Foundation of China (31071541)a program for Changjiang Scholars and Innovative Research Team in University (IRT1188)
文摘As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol(DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane(R134a) extraction in combination with gas chromatography-mass spectrometry(GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C_(18) and NH_2 solid phase extraction(SPE). Finally, the analyte was derived by heptafluorobutyric anhydride(HFBA), followed by GC-MS analysis. Response surface methodology(RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26℃; amount of co-solvent volume, 4.7 m L. Under this condition, at a spiked level of 1, 5, 10 μg kg^(-1), the mean recovery of DES was more than 90% with relative standard deviations(RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.
文摘The basics and applications of acousto-optic devices are described.The applications include acousto-optic spectrum analyzer,acousto-optic deflector,acousto-optic processors and acousto-optic digital matrix computer.
文摘Fourier transform infrared attenuated total reflectance （FTIR-ATR） spectroscopy was employed to characterize rapeseed oils. The spectral features of rapeseed oils were first investigated. Spectral data was processed using principal component analysis （PCA） and linear discriminant analysis （LDA） to discriminate the oils from three cultivars of rapeseeds. As a result, 100% discrimination accuracy was obtained by LDA. Furthermore, the applicability of FTIR-ATR spectroscopy to characterize the changes of rapeseed oils caused by thermal treatment was studied. The rapeseed oil at 60 ℃ was regularly subjected to spectral measurement, and the spectral changes induced by thermal treatment were analyzed and discussed. This study had demonstrated the good performance of FTIR-ATR spectroscopy in characterizing rapeseed oils.
