A cautious projection BFGS method is proposed for solving nonconvex unconstrained optimization problems.The global convergence of this method as well as a stronger general convergence result can be proven without a gr...A cautious projection BFGS method is proposed for solving nonconvex unconstrained optimization problems.The global convergence of this method as well as a stronger general convergence result can be proven without a gradient Lipschitz continuity assumption,which is more in line with the actual problems than the existing modified BFGS methods and the traditional BFGS method.Under some additional conditions,the method presented has a superlinear convergence rate,which can be regarded as an extension and supplement of BFGS-type methods with the projection technique.Finally,the effectiveness and application prospects of the proposed method are verified by numerical experiments.展开更多
This study aims to reduce the interference of ambient noise in mobile communication,improve the accuracy and authenticity of information transmitted by sound,and guarantee the accuracy of voice information deliv-ered ...This study aims to reduce the interference of ambient noise in mobile communication,improve the accuracy and authenticity of information transmitted by sound,and guarantee the accuracy of voice information deliv-ered by mobile communication.First,the principles and techniques of speech enhancement are analyzed,and a fast lateral recursive least square method(FLRLS method)is adopted to process sound data.Then,the convolutional neural networks(CNNs)-based noise recognition CNN(NR-CNN)algorithm and speech enhancement model are proposed.Finally,related experiments are designed to verify the performance of the proposed algorithm and model.The experimental results show that the noise classification accuracy of the NR-CNN noise recognition algorithm is higher than 99.82%,and the recall rate and F1 value are also higher than 99.92.The proposed sound enhance-ment model can effectively enhance the original sound in the case of noise interference.After the CNN is incorporated,the average value of all noisy sound perception quality evaluation system values is improved by over 21%compared with that of the traditional noise reduction method.The proposed algorithm can adapt to a variety of voice environments and can simultaneously enhance and reduce noise processing on a variety of different types of voice signals,and the processing effect is better than that of traditional sound enhancement models.In addition,the sound distortion index of the proposed speech enhancement model is inferior to that of the control group,indicating that the addition of the CNN neural network is less likely to cause sound signal distortion in various sound environments and shows superior robustness.In summary,the proposed CNN-based speech enhancement model shows significant sound enhancement effects,stable performance,and strong adapt-ability.This study provides a reference and basis for research applying neural networks in speech enhancement.展开更多
Disease in clams frequently occurred over the last decade and has become a serious threat to the clam aquaculture industry and natural stocks.Mass clam mortality events were reported to be associated with the presence...Disease in clams frequently occurred over the last decade and has become a serious threat to the clam aquaculture industry and natural stocks.Mass clam mortality events were reported to be associated with the presence of opportunistic pathogen vibrio.However,the complexity of infection that occurs in the natural environment remains poorly understood.In this study,we smulated a natural disease outbreak by vibrio immersion infection to study the diversity and dynamics of microbiota in the digestive tract of clam Meretrix petechialis during the infection process.Dramatic changes in operational taxonomic unit richness and phylum composition of the bacterial communities were observed during pathogen invasion.In addition,we investigated the potential relationship between microbiota dynamics and host status during disease progression.Results reveal that,at the end stage of vibrio infection,interindividual variation in the digestive tract microbiota increased,as did the diff erence in individual health status.The moribund clams displayed signs of microbial community shifts to low diversity,and the microbial community was characterized by mass proliferation of a few operational taxonomic units.展开更多
As well known,with the increase of world population,improving agricultural production has always been of great importance.Due to the effective protection against pests or pathogenic bacteria and promoting the growth o...As well known,with the increase of world population,improving agricultural production has always been of great importance.Due to the effective protection against pests or pathogenic bacteria and promoting the growth of crops,agrochemical holds vital position in modern agriculture.In this field,introducing sulfur moieties into active ingredients to improve the property of pesticides has been a powerful tool for the development of agrochemical.Thus,the efficient methods for the construction of organosulfur scaffolds existed in agrochemicals are highly desirable,which also attract considerable attentions over the past few decades.Herein,we provide comprehensive introduction of organosulfur agrochemicals and representative synthetic access to sulfur-containing molecules frequently found in pesticides with the utilization of various sulfurizing agents,point out the potential direction for further development.展开更多
We have disclosed a novel,efficient radicalmediated intermolecular fluoroalkylative olefination of unactivated alkenes.The transformation proceeded through a radical docking-migration cascade,in which a portfolio of s...We have disclosed a novel,efficient radicalmediated intermolecular fluoroalkylative olefination of unactivated alkenes.The transformation proceeded through a radical docking-migration cascade,in which a portfolio of strategically designed dual-function alkenylating reagents was harnessed to afford vinylated products with exclusive E-configuration.The reaction featured mild conditions,broad functional group compatibility,and unique chemo-,regio-,and stereoselectivities.The protocol has also provided a useful approach for late-stage olefination of complex natural products and drug derivatives containing alkenyl moieties.展开更多
基金supported by the Guangxi Science and Technology base and Talent Project(AD22080047)the National Natural Science Foundation of Guangxi Province(2023GXNFSBA 026063)+1 种基金the Innovation Funds of Chinese University(2021BCF03001)the special foundation for Guangxi Ba Gui Scholars.
文摘A cautious projection BFGS method is proposed for solving nonconvex unconstrained optimization problems.The global convergence of this method as well as a stronger general convergence result can be proven without a gradient Lipschitz continuity assumption,which is more in line with the actual problems than the existing modified BFGS methods and the traditional BFGS method.Under some additional conditions,the method presented has a superlinear convergence rate,which can be regarded as an extension and supplement of BFGS-type methods with the projection technique.Finally,the effectiveness and application prospects of the proposed method are verified by numerical experiments.
基金supported by General Project of Philosophy and Social Science Research in Colleges and Universities in Jiangsu Province(2022SJYB0712)Research Development Fund for Young Teachers of Chengxian College of Southeast University(z0037)Special Project of Ideological and Political Education Reform and Research Course(yjgsz2206).
文摘This study aims to reduce the interference of ambient noise in mobile communication,improve the accuracy and authenticity of information transmitted by sound,and guarantee the accuracy of voice information deliv-ered by mobile communication.First,the principles and techniques of speech enhancement are analyzed,and a fast lateral recursive least square method(FLRLS method)is adopted to process sound data.Then,the convolutional neural networks(CNNs)-based noise recognition CNN(NR-CNN)algorithm and speech enhancement model are proposed.Finally,related experiments are designed to verify the performance of the proposed algorithm and model.The experimental results show that the noise classification accuracy of the NR-CNN noise recognition algorithm is higher than 99.82%,and the recall rate and F1 value are also higher than 99.92.The proposed sound enhance-ment model can effectively enhance the original sound in the case of noise interference.After the CNN is incorporated,the average value of all noisy sound perception quality evaluation system values is improved by over 21%compared with that of the traditional noise reduction method.The proposed algorithm can adapt to a variety of voice environments and can simultaneously enhance and reduce noise processing on a variety of different types of voice signals,and the processing effect is better than that of traditional sound enhancement models.In addition,the sound distortion index of the proposed speech enhancement model is inferior to that of the control group,indicating that the addition of the CNN neural network is less likely to cause sound signal distortion in various sound environments and shows superior robustness.In summary,the proposed CNN-based speech enhancement model shows significant sound enhancement effects,stable performance,and strong adapt-ability.This study provides a reference and basis for research applying neural networks in speech enhancement.
基金Supported by the National Natural Science Foundation of China(No.31772845)the China Agriculture Research System(No.CARS-49)+1 种基金the Science and Technology Service Network Initiative of the Chinese Academy of Sciences(No.KFJ-STS-ZDTP-049)the Foundation of Zhejiang Key Laboratory of Exploitation and Preservation of Coastal Bio-Resource(No.J2018001)。
文摘Disease in clams frequently occurred over the last decade and has become a serious threat to the clam aquaculture industry and natural stocks.Mass clam mortality events were reported to be associated with the presence of opportunistic pathogen vibrio.However,the complexity of infection that occurs in the natural environment remains poorly understood.In this study,we smulated a natural disease outbreak by vibrio immersion infection to study the diversity and dynamics of microbiota in the digestive tract of clam Meretrix petechialis during the infection process.Dramatic changes in operational taxonomic unit richness and phylum composition of the bacterial communities were observed during pathogen invasion.In addition,we investigated the potential relationship between microbiota dynamics and host status during disease progression.Results reveal that,at the end stage of vibrio infection,interindividual variation in the digestive tract microbiota increased,as did the diff erence in individual health status.The moribund clams displayed signs of microbial community shifts to low diversity,and the microbial community was characterized by mass proliferation of a few operational taxonomic units.
基金support provided by NSFC(22125103 and 21971065)STCSM(20XD1421500 and 22JC1401000)Shanghai Pujiang Program(22PJD022).
文摘As well known,with the increase of world population,improving agricultural production has always been of great importance.Due to the effective protection against pests or pathogenic bacteria and promoting the growth of crops,agrochemical holds vital position in modern agriculture.In this field,introducing sulfur moieties into active ingredients to improve the property of pesticides has been a powerful tool for the development of agrochemical.Thus,the efficient methods for the construction of organosulfur scaffolds existed in agrochemicals are highly desirable,which also attract considerable attentions over the past few decades.Herein,we provide comprehensive introduction of organosulfur agrochemicals and representative synthetic access to sulfur-containing molecules frequently found in pesticides with the utilization of various sulfurizing agents,point out the potential direction for further development.
基金the financial support from the National Natural Science Foundation of China(grant no.21971173)the Project of Scientific and Technologic Infrastructure of Suzhou(grant no.SZS201905)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘We have disclosed a novel,efficient radicalmediated intermolecular fluoroalkylative olefination of unactivated alkenes.The transformation proceeded through a radical docking-migration cascade,in which a portfolio of strategically designed dual-function alkenylating reagents was harnessed to afford vinylated products with exclusive E-configuration.The reaction featured mild conditions,broad functional group compatibility,and unique chemo-,regio-,and stereoselectivities.The protocol has also provided a useful approach for late-stage olefination of complex natural products and drug derivatives containing alkenyl moieties.
