Wave fields in Beibu Bay during Typhoon Damrey (2005) were simulated by SWAN wave model through inputting high resolution reanalysis wind fields data, current and water level data. Comparisons for wind input and wav...Wave fields in Beibu Bay during Typhoon Damrey (2005) were simulated by SWAN wave model through inputting high resolution reanalysis wind fields data, current and water level data. Comparisons for wind input and wave hindcast between observation and simulation show good consistency. Distributions of wave parameters such as wave height, wave period, wave length and wave direction under typhoon wind forcing were given. Also, the directional spectra related to the different position from the typhoon center were discussed. And at last, the variation and characteristics of observed frequency spectrum during the passage of Damrey were presented.展开更多
The combination of pyrolysis high resolution gas chromatography and pat- tern recognition techniques is a powerful tool for the classification of traditional Chinese drug.A study has been completed on 55 Beimu samples...The combination of pyrolysis high resolution gas chromatography and pat- tern recognition techniques is a powerful tool for the classification of traditional Chinese drug.A study has been completed on 55 Beimu samples of five different geographic origins: Eastern China.Central China.South-western China,North-western China and North-eastern China.Principal component analysis and SIMCA are applied to effectively classifying the samples according to the origin of the plants.The chemical information contained in the high resolution gas chromatographic data is sufficient to characterize the geographic origin of sam- pies.展开更多
DNA fingerprinting among members of the Chinese drug Pu Gong Ying(Taraxacum mongolicum Hand,-Mazz.)and six adulterants of Tu Gong Ying were demonstrated with random-primed polymerase chain reaction(PCR)including arbit...DNA fingerprinting among members of the Chinese drug Pu Gong Ying(Taraxacum mongolicum Hand,-Mazz.)and six adulterants of Tu Gong Ying were demonstrated with random-primed polymerase chain reaction(PCR)including arbitrarily primed polymerase chain reaction(AP-PCR)and random amplified polymorphic DNA(RAPD).Distinctive,reproducible genomic fingerprints from DNA from 7 species belonged to Compositae were generated with two long(20 and 24 mer)and one short(10 mer)randomly chosen primers.The Pu Gong Ying can be differentiated from six species of Tu Gong Ying according to the banding pattems of their amplified DNA on agarose gels.The results showed that AP-PCR and RAPD methods can be used for identifying Chinese drugs.Moreover,the Similarity Indexes of the genomic DNA fingerprints showed that Pu Gong Ying and its adulterants are unrelated.Therefore,AP-PCR and RAPD methods can be used for identifying Chinese drugs.展开更多
The inheritance of chloroplast DNA (cpDNA) in sweet potato (Ipomoea batatas Lain.) was analyzed using DNA restriction fingerprinting. The cpDNA fingerprints of hybrids from reciprocal crosses between Xushu18 and AB78-...The inheritance of chloroplast DNA (cpDNA) in sweet potato (Ipomoea batatas Lain.) was analyzed using DNA restriction fingerprinting. The cpDNA fingerprints of hybrids from reciprocal crosses between Xushu18 and AB78-1 were found to be identical to those of their female parents, which reveals that cpDNA of sweet potato is maternally inherited in this intervarietal crossing. This maternal cpDNA transmission pattern does not accord with the putative one based on former cytological studies. The plastid inheritance in Convolvulaceae has been briefly reviewed in this study, and the utility of DNA restriction fingerprinting analysis in the study of plastid inheritance is also discussed.展开更多
To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in Septemb...To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.展开更多
[Objective] This study aimed to analyze the ploidy of Chinese old roses and their progenies. [Method] The ploidy level of 38 roses was examined by the flow cytometry. [Result] The four Chinese old roses that influence...[Objective] This study aimed to analyze the ploidy of Chinese old roses and their progenies. [Method] The ploidy level of 38 roses was examined by the flow cytometry. [Result] The four Chinese old roses that influenced breeding of mod- ern roses were diploid. Since the progenies of these Chinese old roses crossed with the tetraploid European old roses were almost tetraploid, it is probable that the pro- genies were arisen by the unreduced gametes of the Chinese old roses. Other Chi- nese old roses analysed were triploid, it was presumed that triploids and diploids were intermingled in China of the 1700s and the plant hunters preferred the more fertile Chinese old roses to be introduced to Europe. Sixteen hybrids of Chinese old rose originated in China consisted of six diploids, five triploids and five tetraploids. [Conclusion] Although these diploid Chinese roses might be the progeny brought by crossing among only Chinese old roses, it was considered that triploids and tetraploids have been arisen by crossing between European old roses and Chinese old rose.展开更多
The initial corrosion behavior of pure zinc in a simulated tropical marine atmosphere was investigated using gravimetric method,scanning electron microscope combined with energy dispersive spectroscopy(SEM-EDS),X-ray ...The initial corrosion behavior of pure zinc in a simulated tropical marine atmosphere was investigated using gravimetric method,scanning electron microscope combined with energy dispersive spectroscopy(SEM-EDS),X-ray diffractometry(XRD),Fourier transform infrared spectrometry(FTIR)and electrochemical impedance spectroscopy(EIS).The kinetics of corrosion process is a decelerating process following the empirical equation D=At^n(n<1).The protectiveness of the corrosion product layer could be attributed to the formation of simonkolleite,Zn5(OH)8Cl2·H2O,which could inhibit the rate determining step,namely charge transfer step,of the electrochemical corrosion process.A model of the evolution process of the product layers formed on zinc was proposed.In addition,the regularity of the corrosion rate of zinc as a function of the NaCl deposition rate can be described by a power function.展开更多
The resonator fiber optic gyro (R-FOG) ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-F...The resonator fiber optic gyro (R-FOG) ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-FOG is set up using phase modulation spectroscopy. First,the demodulation curve is obtained using a lock-in amplifier. From the demodulation signal,a gyro dynamic range of ± 4.2rad/s is obtained. Then,using different phase modulation frequencies,the open-loop gyro output signal is measured when the gyro is rotated clockwise or counterclockwise. The bias drift as a function of time is also measured. The fluctuation of the output over 5s is about 0.02rad/s. The drift can be reduced by taking countermeasures against system noise.展开更多
This paper proposes a novel microphone array speech denoising scheme based on tensor filtering methods including truncated HOSVD(High-Order Singular Value Decomposition), low rank tensor approximation and multi-mode W...This paper proposes a novel microphone array speech denoising scheme based on tensor filtering methods including truncated HOSVD(High-Order Singular Value Decomposition), low rank tensor approximation and multi-mode Wiener filtering. Microphone array speech signal is represented in three-order tensor space with channel, time, and spectrum modes and then tensor filtering model can be designed to process the multiway array data. As to the first method, noise can be reduced through the truncated HOSVD which is a simple scheme in tensor processing. It is more accurate to find the lower-rank approximation of the three-order tensor with Tucker model. Then MDL(Minimum Description Length) criterion is used to estimate the optimal tensor rank in the second method. Further, multimode Wiener filtering approach upon tensor analysis can be considered as the spanning of one-mode wiener filtering. How to take advantages of tensor model to obtain a set of filters is the heart of the novel scheme. The performances of the proposed three approaches are evaluated with objective indexes and listening quality test. The experimental results indicate that the proposed tenor filtering methods have potential ability of retrieving the target signal from noisy microphone array signal and the multi-mode Wiener filtering method provides the best denoising results among the three ones.展开更多
Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis (e...Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis (e. g. the pushover analysis), and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.展开更多
AIM: Real-time and rapid Identification of the malignant tissue can be performed during or before surgical operation. Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (...AIM: Real-time and rapid Identification of the malignant tissue can be performed during or before surgical operation. Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (FTIR) spectroscopy and fiber-optic technology. METHODS: A total of five patients with large intestine cancer were detected in vivo and in situ. Of them, three cases of colon cancer and one case of cecum cancer were detected intraoperatively and in vivo by using a FTIR spectrometer during surgical operation, and one case of rectum cancer was explored non-invasively and in vivo before the surgical operation. Normal and malignant colorectal tissues were detected in vivo and in situ using FTIR spectroscopy on the basis of fundamental studies. RESULTS: There were significant differences between FTIR spectra of normal and malignant colorectal tissues detected in vivo and in situ. Experimental results revealed that the spectral characteristics of normal and malignant tissues found in vivo and in situ were similar to those obtained from in vitro measurement in our previous fundamental research. CONCLUSION: FTIR fiber-optic attenuated total reflectance (ATR) spectroscopy can identify in situ and in vivo colorectal cancer. FTIR spectroscopie method with fiber optics is a non-invasive, rapid, accurate and in vivo cancer detection technique in clinical diagnosis.展开更多
The carbonization process of a sucrose‐RuCl3/SBA‐15composite towards a Ru‐containing ordered mesoporous carbon(Ru‐OMC)catalyst was studied by in situ temperature‐programmed infrared spectroscopy to identify the s...The carbonization process of a sucrose‐RuCl3/SBA‐15composite towards a Ru‐containing ordered mesoporous carbon(Ru‐OMC)catalyst was studied by in situ temperature‐programmed infrared spectroscopy to identify the stabilization role of organic carbon precursors during the formation of highly dispersed Ru nanoparticles.The results show that the formation of metal carbonyl species results in the formation of homogeneously distributed Ru nanoparticles,and the rigid silica support and carbon matrix around the Ru(CO)x complex can significantly avoid the sintering and agglomeration of Ru metal particles during elevated temperature thermal treatment.These results ultimately demonstrate that sucrose plays important roles in the formation of homogeneously distributed Ru nanoparticles in a porous carbon matrix.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.展开更多
GeO_(2) is commonly used as dopant to adjust the refractive index profile(RIP)and the acoustic velocity profile(AVP)in the fiber,thereby forming different Brillouin gain spectrum(BGS)characteristics such as Brillouin ...GeO_(2) is commonly used as dopant to adjust the refractive index profile(RIP)and the acoustic velocity profile(AVP)in the fiber,thereby forming different Brillouin gain spectrum(BGS)characteristics such as Brillouin gain,acoustic mode number and peak intensity difference.When an optical fiber is used in optical fiber sensing or communication system,its BGS characteristics may play an important role in determining the performance of the system.In this paper,finite element analysis(FEA)method is used to study the influence of refractive index distribution and its corresponding AVP on the BGS in step-index,graded-index,and complex-index optical fibers.A new method has also been proposed to efficiently discriminate acoustic mode solution and obtain the new and full images of total Brillouin gain and acoustic modes number of the fiber as a function of the refractive index distribution,considering the influence of changing the refractive index difference and the geometric size simultaneously.For each type of optical fiber,the recommended parameter range is provided for optical fiber sensing and optical fiber communication.Moreover,the suitable optical fiber with close peak intensity in its multi-peak BGS is explored and achieved,which can be used in Brillouin beat spectrum detection systems to improve sensing accuracy.展开更多
In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have establishe...In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.展开更多
We investigate the area and entropy spectra of D-dimensional large Schwarzschild black holes. By utilizing the new physical interpretation of quasinormal mode frequency we find that a large Schwarzschild-AdS black hol...We investigate the area and entropy spectra of D-dimensional large Schwarzschild black holes. By utilizing the new physical interpretation of quasinormal mode frequency we find that a large Schwarzschild-AdS black hole has an equally spaced area spectrum and an equidistant entropy spectrum; both are dependent on the spacetime dimension.展开更多
Research on quantitative models of suspended sediment concentration (SSC) using remote sensing technology is very important to understand the scouting and siltation variation in harbors and water channels. Based onl...Research on quantitative models of suspended sediment concentration (SSC) using remote sensing technology is very important to understand the scouting and siltation variation in harbors and water channels. Based onlaboratory study of the relationship between different suspended sediment concentrations and reflectance spectra measured synchronously, quantitative inversion models of SSC based on single factor, band ratio and sediment parameter were developed, which provides an effective method to retrieve the SSC from satellite images. Results show that the bl (430-500nm) and b3 (670-735nm) are the optimal wavelengths for the estimation of lower SSC and the b4 (780-835nm) is the optimal wavelength to estimate the higher SSC. Furthermore the band ratio B2/B3 can be used to simulate the variation of lower SSC better and the B4/B1 to estimate the higher SSC accurately. Also the inversion models developed by sediment parameters of higher and lower SSCs can get a relatively higher accuracy than the single factor and band ratio models.展开更多
The dispersions of the top interface optical phonons and the side interface optical phonons in cylindrical quantum dots are solved by using the dielectric continuum model. Our calculation mainly focuses on the frequen...The dispersions of the top interface optical phonons and the side interface optical phonons in cylindrical quantum dots are solved by using the dielectric continuum model. Our calculation mainly focuses on the frequency dependence of the IO phonon modes on the wave-vector and quantum number in the cylindrical quantum dot system.Results reveal that the frequency of top interface optical phonon sensitively depends on the discrete wave-vector in z direction and the azimuthal quantum number, while that of the side interface optical phonon mode depends on the radial and azimuthal quantum numbers. These features are obviously different from those in quantum well, quantum well wire,and spherical quantum dot systems. The limited frequencies of interface optical modes for the large wave-vector or quantum number approach two certain constant values, and the math and physical reasons for this feature have been explained reasonably.展开更多
For understanding more about the water exchange between the Kuroshio and the East China Sea,We studied the variability of the Kuroshio in the East China Sea(ECS) in the period of 1991 to 2008 using a three-dimensional...For understanding more about the water exchange between the Kuroshio and the East China Sea,We studied the variability of the Kuroshio in the East China Sea(ECS) in the period of 1991 to 2008 using a three-dimensional circulation model,and calculated Kuroshio onshore volume transport in the ECS at the minimum of 0.48 Sv(1 Sv ;106 m3/s) in summer and the maximum of 1.69 Sv in winter.Based on the data of WOA05 and NCEP,The modeled result indicates that the Kuroshio transport east of Taiwan Island decreased since 2000.Lateral movements tended to be stronger at two ends of the Kuroshio in the ECS than that of the middle segment.In addition,we applied a spectral mixture model(SMM) to determine the exchange zone between the Kuroshio and the shelf water of the ECS.The result reveals a significantly negative correlation(coefficient of-0.78) between the area of exchange zone and the Kuroshio onshore transport at 200 m isobath in the ECS.This conclusion brings a new view for the water exchange between the Kuroshio and the East China Sea.Additional to annual and semi-annual signals,intra-seasonal signal of probably the Pacific origin may trigger the events of Kuroshio intrusion and exchange in the ECS.展开更多
In this paper, we show that if T is p-ω-hyponormal, the nonzero points of the approximate and joint approximate point spectrum of T are identical; Moreover, we obtain a pair of inequalities similar to p-ω-hyponormal...In this paper, we show that if T is p-ω-hyponormal, the nonzero points of the approximate and joint approximate point spectrum of T are identical; Moreover, we obtain a pair of inequalities similar to p-ω-hyponormal operators.展开更多
文摘Wave fields in Beibu Bay during Typhoon Damrey (2005) were simulated by SWAN wave model through inputting high resolution reanalysis wind fields data, current and water level data. Comparisons for wind input and wave hindcast between observation and simulation show good consistency. Distributions of wave parameters such as wave height, wave period, wave length and wave direction under typhoon wind forcing were given. Also, the directional spectra related to the different position from the typhoon center were discussed. And at last, the variation and characteristics of observed frequency spectrum during the passage of Damrey were presented.
文摘The combination of pyrolysis high resolution gas chromatography and pat- tern recognition techniques is a powerful tool for the classification of traditional Chinese drug.A study has been completed on 55 Beimu samples of five different geographic origins: Eastern China.Central China.South-western China,North-western China and North-eastern China.Principal component analysis and SIMCA are applied to effectively classifying the samples according to the origin of the plants.The chemical information contained in the high resolution gas chromatographic data is sufficient to characterize the geographic origin of sam- pies.
文摘DNA fingerprinting among members of the Chinese drug Pu Gong Ying(Taraxacum mongolicum Hand,-Mazz.)and six adulterants of Tu Gong Ying were demonstrated with random-primed polymerase chain reaction(PCR)including arbitrarily primed polymerase chain reaction(AP-PCR)and random amplified polymorphic DNA(RAPD).Distinctive,reproducible genomic fingerprints from DNA from 7 species belonged to Compositae were generated with two long(20 and 24 mer)and one short(10 mer)randomly chosen primers.The Pu Gong Ying can be differentiated from six species of Tu Gong Ying according to the banding pattems of their amplified DNA on agarose gels.The results showed that AP-PCR and RAPD methods can be used for identifying Chinese drugs.Moreover,the Similarity Indexes of the genomic DNA fingerprints showed that Pu Gong Ying and its adulterants are unrelated.Therefore,AP-PCR and RAPD methods can be used for identifying Chinese drugs.
文摘The inheritance of chloroplast DNA (cpDNA) in sweet potato (Ipomoea batatas Lain.) was analyzed using DNA restriction fingerprinting. The cpDNA fingerprints of hybrids from reciprocal crosses between Xushu18 and AB78-1 were found to be identical to those of their female parents, which reveals that cpDNA of sweet potato is maternally inherited in this intervarietal crossing. This maternal cpDNA transmission pattern does not accord with the putative one based on former cytological studies. The plastid inheritance in Convolvulaceae has been briefly reviewed in this study, and the utility of DNA restriction fingerprinting analysis in the study of plastid inheritance is also discussed.
文摘To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.
文摘[Objective] This study aimed to analyze the ploidy of Chinese old roses and their progenies. [Method] The ploidy level of 38 roses was examined by the flow cytometry. [Result] The four Chinese old roses that influenced breeding of mod- ern roses were diploid. Since the progenies of these Chinese old roses crossed with the tetraploid European old roses were almost tetraploid, it is probable that the pro- genies were arisen by the unreduced gametes of the Chinese old roses. Other Chi- nese old roses analysed were triploid, it was presumed that triploids and diploids were intermingled in China of the 1700s and the plant hunters preferred the more fertile Chinese old roses to be introduced to Europe. Sixteen hybrids of Chinese old rose originated in China consisted of six diploids, five triploids and five tetraploids. [Conclusion] Although these diploid Chinese roses might be the progeny brought by crossing among only Chinese old roses, it was considered that triploids and tetraploids have been arisen by crossing between European old roses and Chinese old rose.
基金Project (201604046014) supported by Guangzhou Industry-University-Research Collaborative Innovation Alliance Special Program,ChinaProjects (51671197,51601199) supported by the National Natural Science Foundation of China
文摘The initial corrosion behavior of pure zinc in a simulated tropical marine atmosphere was investigated using gravimetric method,scanning electron microscope combined with energy dispersive spectroscopy(SEM-EDS),X-ray diffractometry(XRD),Fourier transform infrared spectrometry(FTIR)and electrochemical impedance spectroscopy(EIS).The kinetics of corrosion process is a decelerating process following the empirical equation D=At^n(n<1).The protectiveness of the corrosion product layer could be attributed to the formation of simonkolleite,Zn5(OH)8Cl2·H2O,which could inhibit the rate determining step,namely charge transfer step,of the electrochemical corrosion process.A model of the evolution process of the product layers formed on zinc was proposed.In addition,the regularity of the corrosion rate of zinc as a function of the NaCl deposition rate can be described by a power function.
文摘The resonator fiber optic gyro (R-FOG) ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-FOG is set up using phase modulation spectroscopy. First,the demodulation curve is obtained using a lock-in amplifier. From the demodulation signal,a gyro dynamic range of ± 4.2rad/s is obtained. Then,using different phase modulation frequencies,the open-loop gyro output signal is measured when the gyro is rotated clockwise or counterclockwise. The bias drift as a function of time is also measured. The fluctuation of the output over 5s is about 0.02rad/s. The drift can be reduced by taking countermeasures against system noise.
基金supported by the National Natural Science Foundation of China(No.61571044,No.11590772,No.61473041 and No.61620106002)
文摘This paper proposes a novel microphone array speech denoising scheme based on tensor filtering methods including truncated HOSVD(High-Order Singular Value Decomposition), low rank tensor approximation and multi-mode Wiener filtering. Microphone array speech signal is represented in three-order tensor space with channel, time, and spectrum modes and then tensor filtering model can be designed to process the multiway array data. As to the first method, noise can be reduced through the truncated HOSVD which is a simple scheme in tensor processing. It is more accurate to find the lower-rank approximation of the three-order tensor with Tucker model. Then MDL(Minimum Description Length) criterion is used to estimate the optimal tensor rank in the second method. Further, multimode Wiener filtering approach upon tensor analysis can be considered as the spanning of one-mode wiener filtering. How to take advantages of tensor model to obtain a set of filters is the heart of the novel scheme. The performances of the proposed three approaches are evaluated with objective indexes and listening quality test. The experimental results indicate that the proposed tenor filtering methods have potential ability of retrieving the target signal from noisy microphone array signal and the multi-mode Wiener filtering method provides the best denoising results among the three ones.
基金The National Basic Research Program of China(973 Program)(No.2007CB714200)
文摘Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis (e. g. the pushover analysis), and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.
基金Supported by the National Natural Science Foundation of China, No. 30371604 State Key Project of China, No. 2002CCA01900
文摘AIM: Real-time and rapid Identification of the malignant tissue can be performed during or before surgical operation. Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (FTIR) spectroscopy and fiber-optic technology. METHODS: A total of five patients with large intestine cancer were detected in vivo and in situ. Of them, three cases of colon cancer and one case of cecum cancer were detected intraoperatively and in vivo by using a FTIR spectrometer during surgical operation, and one case of rectum cancer was explored non-invasively and in vivo before the surgical operation. Normal and malignant colorectal tissues were detected in vivo and in situ using FTIR spectroscopy on the basis of fundamental studies. RESULTS: There were significant differences between FTIR spectra of normal and malignant colorectal tissues detected in vivo and in situ. Experimental results revealed that the spectral characteristics of normal and malignant tissues found in vivo and in situ were similar to those obtained from in vitro measurement in our previous fundamental research. CONCLUSION: FTIR fiber-optic attenuated total reflectance (ATR) spectroscopy can identify in situ and in vivo colorectal cancer. FTIR spectroscopie method with fiber optics is a non-invasive, rapid, accurate and in vivo cancer detection technique in clinical diagnosis.
基金supported by the Natural Science Foundation of Zhejiang Province(LY17B030010)~~
文摘The carbonization process of a sucrose‐RuCl3/SBA‐15composite towards a Ru‐containing ordered mesoporous carbon(Ru‐OMC)catalyst was studied by in situ temperature‐programmed infrared spectroscopy to identify the stabilization role of organic carbon precursors during the formation of highly dispersed Ru nanoparticles.The results show that the formation of metal carbonyl species results in the formation of homogeneously distributed Ru nanoparticles,and the rigid silica support and carbon matrix around the Ru(CO)x complex can significantly avoid the sintering and agglomeration of Ru metal particles during elevated temperature thermal treatment.These results ultimately demonstrate that sucrose plays important roles in the formation of homogeneously distributed Ru nanoparticles in a porous carbon matrix.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.
基金supported by the National Natural Science Foundation of China(Nos.61875086,61377086)Aerospace Science Foundation of China(No.2016ZD52042)Foundation of Graduate Innovation Center in Nanjing University of Aeronautics and Astronautics(No.kfjj20170801)。
文摘GeO_(2) is commonly used as dopant to adjust the refractive index profile(RIP)and the acoustic velocity profile(AVP)in the fiber,thereby forming different Brillouin gain spectrum(BGS)characteristics such as Brillouin gain,acoustic mode number and peak intensity difference.When an optical fiber is used in optical fiber sensing or communication system,its BGS characteristics may play an important role in determining the performance of the system.In this paper,finite element analysis(FEA)method is used to study the influence of refractive index distribution and its corresponding AVP on the BGS in step-index,graded-index,and complex-index optical fibers.A new method has also been proposed to efficiently discriminate acoustic mode solution and obtain the new and full images of total Brillouin gain and acoustic modes number of the fiber as a function of the refractive index distribution,considering the influence of changing the refractive index difference and the geometric size simultaneously.For each type of optical fiber,the recommended parameter range is provided for optical fiber sensing and optical fiber communication.Moreover,the suitable optical fiber with close peak intensity in its multi-peak BGS is explored and achieved,which can be used in Brillouin beat spectrum detection systems to improve sensing accuracy.
文摘In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.
基金Supported by the National Natural Science Foundation of China under Grant No.10275030Cuiying Project of Lanzhou University under Grant No.225000-582404
文摘We investigate the area and entropy spectra of D-dimensional large Schwarzschild black holes. By utilizing the new physical interpretation of quasinormal mode frequency we find that a large Schwarzschild-AdS black hole has an equally spaced area spectrum and an equidistant entropy spectrum; both are dependent on the spacetime dimension.
基金Under the auspices of the Key Program of National Natural Science Foundation of China(No.50339010)Huaihe Valley Open Fund Projects(No.Hx2007)
文摘Research on quantitative models of suspended sediment concentration (SSC) using remote sensing technology is very important to understand the scouting and siltation variation in harbors and water channels. Based onlaboratory study of the relationship between different suspended sediment concentrations and reflectance spectra measured synchronously, quantitative inversion models of SSC based on single factor, band ratio and sediment parameter were developed, which provides an effective method to retrieve the SSC from satellite images. Results show that the bl (430-500nm) and b3 (670-735nm) are the optimal wavelengths for the estimation of lower SSC and the b4 (780-835nm) is the optimal wavelength to estimate the higher SSC. Furthermore the band ratio B2/B3 can be used to simulate the variation of lower SSC better and the B4/B1 to estimate the higher SSC accurately. Also the inversion models developed by sediment parameters of higher and lower SSCs can get a relatively higher accuracy than the single factor and band ratio models.
文摘The dispersions of the top interface optical phonons and the side interface optical phonons in cylindrical quantum dots are solved by using the dielectric continuum model. Our calculation mainly focuses on the frequency dependence of the IO phonon modes on the wave-vector and quantum number in the cylindrical quantum dot system.Results reveal that the frequency of top interface optical phonon sensitively depends on the discrete wave-vector in z direction and the azimuthal quantum number, while that of the side interface optical phonon mode depends on the radial and azimuthal quantum numbers. These features are obviously different from those in quantum well, quantum well wire,and spherical quantum dot systems. The limited frequencies of interface optical modes for the large wave-vector or quantum number approach two certain constant values, and the math and physical reasons for this feature have been explained reasonably.
基金Supported by the National Basic Research Program of China (973 Program) (Nos. 2005CB422300,2007CB411804,2010CB428904)the National Natural Science Foundation of China (Nos. 40976001,40940025,41006002)+2 种基金Tianjin Municipal Science and Technology Commission Project (No. 09JCYBJC07400)the "111 Project" (No.B07036)the Program for New Century Excellent Talents in University (No. NECT-07-0781)
文摘For understanding more about the water exchange between the Kuroshio and the East China Sea,We studied the variability of the Kuroshio in the East China Sea(ECS) in the period of 1991 to 2008 using a three-dimensional circulation model,and calculated Kuroshio onshore volume transport in the ECS at the minimum of 0.48 Sv(1 Sv ;106 m3/s) in summer and the maximum of 1.69 Sv in winter.Based on the data of WOA05 and NCEP,The modeled result indicates that the Kuroshio transport east of Taiwan Island decreased since 2000.Lateral movements tended to be stronger at two ends of the Kuroshio in the ECS than that of the middle segment.In addition,we applied a spectral mixture model(SMM) to determine the exchange zone between the Kuroshio and the shelf water of the ECS.The result reveals a significantly negative correlation(coefficient of-0.78) between the area of exchange zone and the Kuroshio onshore transport at 200 m isobath in the ECS.This conclusion brings a new view for the water exchange between the Kuroshio and the East China Sea.Additional to annual and semi-annual signals,intra-seasonal signal of probably the Pacific origin may trigger the events of Kuroshio intrusion and exchange in the ECS.
基金Supported by the Education Foundation of Henan Province(2003110006)
文摘In this paper, we show that if T is p-ω-hyponormal, the nonzero points of the approximate and joint approximate point spectrum of T are identical; Moreover, we obtain a pair of inequalities similar to p-ω-hyponormal operators.