Nanoparticles(NPs)have already been widely used in catalysis,antibacterial and coating fields.Compared with the traditional toxic and harmful reducing reagents,green synthesis of NPs by using plant extracts is not onl...Nanoparticles(NPs)have already been widely used in catalysis,antibacterial and coating fields.Compared with the traditional toxic and harmful reducing reagents,green synthesis of NPs by using plant extracts is not only environmental-friendly and cost-effective but also conducive to the multi-level and efficient utilization of wild plant resources.In this study,the aqueous extracts from Sorbus pohuashanensis(SP)and Aronia melanocarpa(AM)fruits were used as the reducing and protective reagents for synthesizing Au/AgNPs,with the characteristics of originality operation and high repeatability.The SP/AM fruit extracts functionalized Au/AgNPs were characterized by UV-vis spectroscopy(UV-vis),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS),scanning electron microscope(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).UV-vis spectrums showed the NPs peaks verified by the presence between 400–550 nm;TEM and SEM demonstrated NPs displayed approximately spherical structures;EDS confirmed the existence of Au/Ag elements;XRD measurements confirmed that the obtained NPs showed highly crystalline structures;FTIR demonstrated the fruits extracts were adsorbed on the surface of NPs.Primary experiments indicated that SP/AM fruit extracts functionalized-NPs could be used as the reagents for removing the organic dyes efficiently;Zone of inhibition tests(ZOI)explained that NPs have slow-release antibacterial activity.展开更多
Sparse decomposition is a new theory in signal processing,with the advantage in that the base(dictionary)used in this theory is over-complete,and can reflect the nature of a signal.Thus,the sparse decomposition of sig...Sparse decomposition is a new theory in signal processing,with the advantage in that the base(dictionary)used in this theory is over-complete,and can reflect the nature of a signal.Thus,the sparse decomposition of signal can obtain sparse representation,which is very important in data compression.The algorithm of compression based on sparse decomposition is investigated.By training on and learning electrocardiogram(ECG)data in the MIT-BIH Arrhythmia Database,we constructed an over-complete dictionary of ECGs.Since the atoms in this dictionary are in accord with the character of ECGs,it is possible that an extensive ECG datum is reconstructed by a few nonzero coefficients and atoms.The proposed compression algorithm can adjust compression ratio according to practical request,and the distortion is low(when the compression ratio is 20∶1,the standard error is 5.11%).The experiments prove the feasibility of the proposed compression algorithm.展开更多
基金support from the Fundamental Research Funds for the Central Universities(2572020DR07)Natural Science Fund of Heilongjiang Province(LH2019B001)+1 种基金the 111 Project(B20088)Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team).
文摘Nanoparticles(NPs)have already been widely used in catalysis,antibacterial and coating fields.Compared with the traditional toxic and harmful reducing reagents,green synthesis of NPs by using plant extracts is not only environmental-friendly and cost-effective but also conducive to the multi-level and efficient utilization of wild plant resources.In this study,the aqueous extracts from Sorbus pohuashanensis(SP)and Aronia melanocarpa(AM)fruits were used as the reducing and protective reagents for synthesizing Au/AgNPs,with the characteristics of originality operation and high repeatability.The SP/AM fruit extracts functionalized Au/AgNPs were characterized by UV-vis spectroscopy(UV-vis),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS),scanning electron microscope(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).UV-vis spectrums showed the NPs peaks verified by the presence between 400–550 nm;TEM and SEM demonstrated NPs displayed approximately spherical structures;EDS confirmed the existence of Au/Ag elements;XRD measurements confirmed that the obtained NPs showed highly crystalline structures;FTIR demonstrated the fruits extracts were adsorbed on the surface of NPs.Primary experiments indicated that SP/AM fruit extracts functionalized-NPs could be used as the reagents for removing the organic dyes efficiently;Zone of inhibition tests(ZOI)explained that NPs have slow-release antibacterial activity.
文摘Sparse decomposition is a new theory in signal processing,with the advantage in that the base(dictionary)used in this theory is over-complete,and can reflect the nature of a signal.Thus,the sparse decomposition of signal can obtain sparse representation,which is very important in data compression.The algorithm of compression based on sparse decomposition is investigated.By training on and learning electrocardiogram(ECG)data in the MIT-BIH Arrhythmia Database,we constructed an over-complete dictionary of ECGs.Since the atoms in this dictionary are in accord with the character of ECGs,it is possible that an extensive ECG datum is reconstructed by a few nonzero coefficients and atoms.The proposed compression algorithm can adjust compression ratio according to practical request,and the distortion is low(when the compression ratio is 20∶1,the standard error is 5.11%).The experiments prove the feasibility of the proposed compression algorithm.
