This letter proposes two algorithms: a novel Quantum Genetic Algorithm (QGA)based on the improvement of Han's Genetic Quantum Algorithm (GQA) and a new Blind Source Separation (BSS) method based on QGA and Indepen...This letter proposes two algorithms: a novel Quantum Genetic Algorithm (QGA)based on the improvement of Han's Genetic Quantum Algorithm (GQA) and a new Blind Source Separation (BSS) method based on QGA and Independent Component Analysis (ICA). The simulation result shows that the efficiency of the new BSS method is obviously higher than that of the Conventional Genetic Algorithm (CGA).展开更多
Vibration signals from diesel engine contain many different components mainly caused by combustion and mechanism operations,several blind source separation techniques are available for decomposing the signal into its ...Vibration signals from diesel engine contain many different components mainly caused by combustion and mechanism operations,several blind source separation techniques are available for decomposing the signal into its components in the case of multichannel measurements,such as independent component analysis（ICA）.However,the source separation of vibration signal from single-channel is impossible.In order to study the source separation from single-channel signal for the purpose of source extraction,the combination method of empirical mode decomposition（EMD） and ICA is proposed in diesel engine signal processing.The performance of the described methods of EMD-wavelet and EMD-ICA in vibration signal application is compared,and the results show that EMD-ICA method outperforms the other,and overcomes the drawback of ICA in the case of single-channel measurement.The independent source signal components can be separated and identified effectively from one-channel measurement by EMD-ICA.Hence,EMD-ICA improves the extraction and identification abilities of source signals from diesel engine vibration measurements.展开更多
Unlike inorganic quantum dots,fluorescent graphene quantum dots(GQDs)display excitation-dependent multiple color emission.In this study,we report N-doped GQDs(N-GQDs)with tailored single color emission by tuning p-con...Unlike inorganic quantum dots,fluorescent graphene quantum dots(GQDs)display excitation-dependent multiple color emission.In this study,we report N-doped GQDs(N-GQDs)with tailored single color emission by tuning p-conjugation degree,which is comparable to the inorganic quantum dot.Starting from citric acid and diethylenetriamine,as prepared N-GQDs display blue,green,and yellow light emission by changing the reaction solvent from water,dimethylformamide(DMF),and solvent free.The X-ray photoelectron spectroscopy,ultraviolet-visible spectra results clearly show the N-GQDs with blue emission(N-GQDs-B)have relatively short effective conjugation length and more carboxyl group because H_(2)O is a polar protic solvent,which tends to donate proton to the reagent to depress the H_(2)O elimination reaction.On the other hand,the polar aprotic solvent(DMF)cannot donate hydrogen,the elimination of H_(2)O is promoted and more nitrogen units enter GQD framework.With the increase of effective p-conjugation length and N content,the emission band of N-GQDS red-shifts to green and yellow.We also demonstrate that N-GQDs could be a potential great biomarker for fluorescent bioimaging.展开更多
Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispen...Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispensable task. Along with the increase in the size of the study area, the derived spectra are becoming more and more alike, such that their dif- ferences can be ignored in favor of a standard. Subsequently, the test size is defined as the Slope Spectrum Critical Area （SSCA）. SSCA is not only the foundation of the slope spectrum calculation but also, to some extent, a reflection of geomorphological development of loess relief. High resolution DEMs are important in extracting the slope spectrum. A set of 48 DEMs with different landform areas of the Loess Plateau in northern Shaanxi province was selected for the experiment. The spatial distribution of SSCA is investigated with a geo-statistical analysis method, resulting in values ranging from 6.18 km^2 to 35.1 km^2. Primary experimental results show that the spatial distribution of SSCA is correlated with the spatial distribution of the soil erosion intensity, to a certain extent reflecting the terrain complexity. The critical area of the slope spectrum presents a spatial variation trend of weak-strong-weak from north to south. Four terrain parameters, gully density, slope skewness, terrain driving force （Td） and slope of slope （SOS）, were chosen as indicators. There exists a good exponential function relationship between SSCA and gully density, terrain driving force （Td） and SOS and a loga- rithmic function relationship between SSCA and slope skewness. Slope skewness increases, and gully density, terrain driving force and SOS decrease with increasing SSCA. SSCA can be utilized as a discriminating factor to identify loess landforms, in that spatial distributions of SSCA and the evolution of loess landforms are correlative. Following the evolution of a loess landform from tableland to gully-hilly region, this also proves that SSCA can repre展开更多
The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/...The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.展开更多
BACKGROUND Myocardial bridge(MB)will compress the mural coronary artery(MCA)during the systole and cause myocardial ischemia.In the diagnosis of coronary heart disease(CHD),because the structure of MB is difficult to ...BACKGROUND Myocardial bridge(MB)will compress the mural coronary artery(MCA)during the systole and cause myocardial ischemia.In the diagnosis of coronary heart disease(CHD),because the structure of MB is difficult to be observed by coronary angiography(CAG),the clinical study of the influence of MB on CHD is lacking.With the advancement of computed tomography coronary angiography technology,detailed observations of the MB anatomy have realized.AIM To explore the main influencing factors of MB-related CHD and to find potential indicators for predicting MB-related CHD.METHODS A total of 1718 patients with suspected CHD due to the symptoms of myocardial ischemia were enrolled as subjects.Patients diagnosed with CHD were included in a CHD group,and patients with no significant abnormalities were included in a control group.In the CHD group,patients were divided into an MB-CHD subgroup if MB-related CHD was found.In the control group,patients were divided into a simple MB subgroup if MB was found.The patient's clinical data and MB-related indicators,including the branch of MB,MB type(superficial/deep type),MB length,MB thickness,systolic and diastolic compression of the MCA,and MCA systolic stenosis rate were recorded and compared.Logistic regression analysis was used to explore the independent influencing factors of MD-related CHD.ROC curve was used to analyze the diagnostic efficacy of potential indicators for MB-related CHD.RESULTS There were 1060 cases in the CHD group and 658 cases in the control group,and there were 236 cases in the MB-CHD subgroup and 52 cases in the simple MB subgroup.Multivariate logistic regression analysis showed that the combined MB had a significant effect on the occurrence of CHD(P<0.05).MB thickness,systolic compression,diastolic compression,and MCA systolic stenosis rate had significant effects on the occurrence of MB-related CHD(P<0.05).The area under the curve(AUC)of the combination of these influencing factors for the diagnosis of MB-related CHD was 0.959,which was significantly hig展开更多
Aims While using phylogenetic and functional approaches to test the mechanisms of community assembly,functional traits often act as the proxy of niches.However,there is little detailed knowledge regarding the correlat...Aims While using phylogenetic and functional approaches to test the mechanisms of community assembly,functional traits often act as the proxy of niches.However,there is little detailed knowledge regarding the correlation between functional traits of tree species and their niches in local communities.We suggest that the co-varying correlation between functional traits and niches should be the premise for using phylogenetic and functional approaches to test mechanisms of community assembly.Using functional traits,phylogenetic and environmental data,this study aims to answer the questions:(i)within local communities,do functional traits of co-occurring species covary with their environmental niches at the species level?and(ii)what is the key ecological process underlying community assembly in Xishuangbanna and Ailaoshan forest dynamic plots(FDPs)?Methods We measured seven functional traits of 229 and 36 common species in Xishuangbanna and Ailaoshan FDPs in tropical and subtropical China,respectively.We also quantified the environmental niches for these species based on conditional probability.We then analyzed the correlations between functional traits and environmental niches using phylogenetic independent contrasts.After examining phylogenetic signals of functional traits using Pagel’sλ,we quantified the phylogenetic and functional dispersion along environmental gradients within local tree communities.Important Findings For target species,functional traits do co-vary with environmental niches at the species level in both of the FDPs,supporting that functional traits can be used as a proxy for local-scale environmental niches.Functional traits show significant phylogenetic signals in both of the FDPs.We found that the phylogenetic and functional dispersion were significantly clustered along topographical gradients in the Ailaoshan FDP but overdispersion in the Xishuangbanna FDP.These patterns of phylogenetic and functional dispersion suggest that environmental filtering plays a key role in structuring local tree 展开更多
基金Supported by the National Natural Science Foundation of China (No.60171029)
文摘This letter proposes two algorithms: a novel Quantum Genetic Algorithm (QGA)based on the improvement of Han's Genetic Quantum Algorithm (GQA) and a new Blind Source Separation (BSS) method based on QGA and Independent Component Analysis (ICA). The simulation result shows that the efficiency of the new BSS method is obviously higher than that of the Conventional Genetic Algorithm (CGA).
基金supported by National Natural Science Foundation of China (Grant No. 50975192)Tianjin Municipal Natural Science Foundation of China (Grant No. 10YFJZJC14100)
文摘Vibration signals from diesel engine contain many different components mainly caused by combustion and mechanism operations,several blind source separation techniques are available for decomposing the signal into its components in the case of multichannel measurements,such as independent component analysis（ICA）.However,the source separation of vibration signal from single-channel is impossible.In order to study the source separation from single-channel signal for the purpose of source extraction,the combination method of empirical mode decomposition（EMD） and ICA is proposed in diesel engine signal processing.The performance of the described methods of EMD-wavelet and EMD-ICA in vibration signal application is compared,and the results show that EMD-ICA method outperforms the other,and overcomes the drawback of ICA in the case of single-channel measurement.The independent source signal components can be separated and identified effectively from one-channel measurement by EMD-ICA.Hence,EMD-ICA improves the extraction and identification abilities of source signals from diesel engine vibration measurements.
基金The authors thank the National Natural Science Foundation of China(No.21301166,21201159,61306081,and 61176016)Science and Technology Department of Jilin Province(No.20130522127JH)are gratefully acknowledged+1 种基金ZS thanks the support of the‘Hundred Talent Program’of CAS and Innovation and Entrepreneurship Program of JilinThe project was supported by Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry and the open research fund program of the State Key Laboratory of Luminescence and Applications.
文摘Unlike inorganic quantum dots,fluorescent graphene quantum dots(GQDs)display excitation-dependent multiple color emission.In this study,we report N-doped GQDs(N-GQDs)with tailored single color emission by tuning p-conjugation degree,which is comparable to the inorganic quantum dot.Starting from citric acid and diethylenetriamine,as prepared N-GQDs display blue,green,and yellow light emission by changing the reaction solvent from water,dimethylformamide(DMF),and solvent free.The X-ray photoelectron spectroscopy,ultraviolet-visible spectra results clearly show the N-GQDs with blue emission(N-GQDs-B)have relatively short effective conjugation length and more carboxyl group because H_(2)O is a polar protic solvent,which tends to donate proton to the reagent to depress the H_(2)O elimination reaction.On the other hand,the polar aprotic solvent(DMF)cannot donate hydrogen,the elimination of H_(2)O is promoted and more nitrogen units enter GQD framework.With the increase of effective p-conjugation length and N content,the emission band of N-GQDS red-shifts to green and yellow.We also demonstrate that N-GQDs could be a potential great biomarker for fluorescent bioimaging.
基金Foundation： National Natural Science Foundation of China, No.41171299, No.41171320, No.41401237
文摘Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispensable task. Along with the increase in the size of the study area, the derived spectra are becoming more and more alike, such that their dif- ferences can be ignored in favor of a standard. Subsequently, the test size is defined as the Slope Spectrum Critical Area （SSCA）. SSCA is not only the foundation of the slope spectrum calculation but also, to some extent, a reflection of geomorphological development of loess relief. High resolution DEMs are important in extracting the slope spectrum. A set of 48 DEMs with different landform areas of the Loess Plateau in northern Shaanxi province was selected for the experiment. The spatial distribution of SSCA is investigated with a geo-statistical analysis method, resulting in values ranging from 6.18 km^2 to 35.1 km^2. Primary experimental results show that the spatial distribution of SSCA is correlated with the spatial distribution of the soil erosion intensity, to a certain extent reflecting the terrain complexity. The critical area of the slope spectrum presents a spatial variation trend of weak-strong-weak from north to south. Four terrain parameters, gully density, slope skewness, terrain driving force （Td） and slope of slope （SOS）, were chosen as indicators. There exists a good exponential function relationship between SSCA and gully density, terrain driving force （Td） and SOS and a loga- rithmic function relationship between SSCA and slope skewness. Slope skewness increases, and gully density, terrain driving force and SOS decrease with increasing SSCA. SSCA can be utilized as a discriminating factor to identify loess landforms, in that spatial distributions of SSCA and the evolution of loess landforms are correlative. Following the evolution of a loess landform from tableland to gully-hilly region, this also proves that SSCA can repre
文摘The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.
文摘BACKGROUND Myocardial bridge(MB)will compress the mural coronary artery(MCA)during the systole and cause myocardial ischemia.In the diagnosis of coronary heart disease(CHD),because the structure of MB is difficult to be observed by coronary angiography(CAG),the clinical study of the influence of MB on CHD is lacking.With the advancement of computed tomography coronary angiography technology,detailed observations of the MB anatomy have realized.AIM To explore the main influencing factors of MB-related CHD and to find potential indicators for predicting MB-related CHD.METHODS A total of 1718 patients with suspected CHD due to the symptoms of myocardial ischemia were enrolled as subjects.Patients diagnosed with CHD were included in a CHD group,and patients with no significant abnormalities were included in a control group.In the CHD group,patients were divided into an MB-CHD subgroup if MB-related CHD was found.In the control group,patients were divided into a simple MB subgroup if MB was found.The patient's clinical data and MB-related indicators,including the branch of MB,MB type(superficial/deep type),MB length,MB thickness,systolic and diastolic compression of the MCA,and MCA systolic stenosis rate were recorded and compared.Logistic regression analysis was used to explore the independent influencing factors of MD-related CHD.ROC curve was used to analyze the diagnostic efficacy of potential indicators for MB-related CHD.RESULTS There were 1060 cases in the CHD group and 658 cases in the control group,and there were 236 cases in the MB-CHD subgroup and 52 cases in the simple MB subgroup.Multivariate logistic regression analysis showed that the combined MB had a significant effect on the occurrence of CHD(P<0.05).MB thickness,systolic compression,diastolic compression,and MCA systolic stenosis rate had significant effects on the occurrence of MB-related CHD(P<0.05).The area under the curve(AUC)of the combination of these influencing factors for the diagnosis of MB-related CHD was 0.959,which was significantly hig
基金National Natural Science Foundation of China(31000201,31370445,31061160188)National Key Basic Research Program of China(2014CB954104)the West Light Foundation of Chinese Academy of Sciences and the Special Program for Basic Research of the Ministry of Science and Technology of China(2012FY10400,2011FY120200).
文摘Aims While using phylogenetic and functional approaches to test the mechanisms of community assembly,functional traits often act as the proxy of niches.However,there is little detailed knowledge regarding the correlation between functional traits of tree species and their niches in local communities.We suggest that the co-varying correlation between functional traits and niches should be the premise for using phylogenetic and functional approaches to test mechanisms of community assembly.Using functional traits,phylogenetic and environmental data,this study aims to answer the questions:(i)within local communities,do functional traits of co-occurring species covary with their environmental niches at the species level?and(ii)what is the key ecological process underlying community assembly in Xishuangbanna and Ailaoshan forest dynamic plots(FDPs)?Methods We measured seven functional traits of 229 and 36 common species in Xishuangbanna and Ailaoshan FDPs in tropical and subtropical China,respectively.We also quantified the environmental niches for these species based on conditional probability.We then analyzed the correlations between functional traits and environmental niches using phylogenetic independent contrasts.After examining phylogenetic signals of functional traits using Pagel’sλ,we quantified the phylogenetic and functional dispersion along environmental gradients within local tree communities.Important Findings For target species,functional traits do co-vary with environmental niches at the species level in both of the FDPs,supporting that functional traits can be used as a proxy for local-scale environmental niches.Functional traits show significant phylogenetic signals in both of the FDPs.We found that the phylogenetic and functional dispersion were significantly clustered along topographical gradients in the Ailaoshan FDP but overdispersion in the Xishuangbanna FDP.These patterns of phylogenetic and functional dispersion suggest that environmental filtering plays a key role in structuring local tree
