In this paper,an algorithm based on a fractional time-frequency spectrum feature is proposed to improve the accuracy of synthetic aperture radar(SAR)target detection.By extending the fractional Gabor transform(FrGT)in...In this paper,an algorithm based on a fractional time-frequency spectrum feature is proposed to improve the accuracy of synthetic aperture radar(SAR)target detection.By extending the fractional Gabor transform(FrGT)into two dimensions,the fractional time-frequency spectrum feature of an image can be obtained.In the achievement process,we search for the optimal order and design the optimal window function to accomplish the two-dimensional optimal FrGT.Finally,the energy attenuation gradient(EAG)feature of the optimal time-frequency spectrum is extracted for high-frequency detection.The simulation results show the proposed algorithm has a good performance in SAR target detection and lays the foundation for recognition.展开更多
With the aid of a postsynthetic metathesis method, an inert nitrogen-rich porphyrinic metal-organic framework can exhibit a high catalytic activity in one-pot deacetalization-Knoevenagel condensation reaction.
The judicious choice of metal clusters and organic building blocks leads to a wide variety of structures for metal–organic frameworks(MOFs).In this work,we demonstrated that relegating the symmetry of a building bloc...The judicious choice of metal clusters and organic building blocks leads to a wide variety of structures for metal–organic frameworks(MOFs).In this work,we demonstrated that relegating the symmetry of a building block can also lead to the proliferation of new MOF structures.Herein,a triangle building block was elongated with reduced symmetry for MOF construction,which gave rise to a novel(3,4,6)-connected idp(based on the definition of Reticular Chemistry Structure Resource,http://rcsr.net/)network(PFC-16)with mesopores and abundant open-metal sites.The framework is composed of the rarely observed tetrakis hexahedral cages,surrounding which are small cages arranged in sodalite topology.The relegated symmetry was required for this novel self-assembly.The obtained MOF with mesopores,a robust backbone,and abundant open-metal sites can incorporate functional species in the structure,which is representatively demonstrated by internalizing the photosensitizer zinc(II)phthalocyanine(ZnPc)and the modifying tumor-targeting molecule folic acid(FA)in PFC-16.The obtained composite FA-ZnPc@nano-PFC-16 shows excellent photodynamic therapy(PDT)efficiency for both in vitro and in vivo experiments,representing a promising candidate for cancer therapy.展开更多
基金supported by the Natural Science Foundation of Sichuan Province of China under Grant No.2022NSFSC40574partially supported by the National Natural Science Foundation of China under Grants No.61571096 and No.61775030.
文摘In this paper,an algorithm based on a fractional time-frequency spectrum feature is proposed to improve the accuracy of synthetic aperture radar(SAR)target detection.By extending the fractional Gabor transform(FrGT)into two dimensions,the fractional time-frequency spectrum feature of an image can be obtained.In the achievement process,we search for the optimal order and design the optimal window function to accomplish the two-dimensional optimal FrGT.Finally,the energy attenuation gradient(EAG)feature of the optimal time-frequency spectrum is extracted for high-frequency detection.The simulation results show the proposed algorithm has a good performance in SAR target detection and lays the foundation for recognition.
基金Financial support of the ligand and MOFs synthesis in part by the Center for Gas Separations Relevant to Clean Energy Technologiesan Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001015+9 种基金part of the U.S. Department of Energy (DOE), ARPA-e (DE-AR0000249)DOENational Energy Technology Laboratory Award (DE-FE0026472)the Welch Foundation under award number A-1725the Welch Endowed Chair to HJZ (A-0030) for support of the structural analysesThe X-ray diffractometers, and crystallographic computing systems in the X-ray Diffraction Laboratory at the Department of Chemistry, Texas A & M University were purchased with funds provided by the National Science Foundation (CHE-9807975, CHE-0079822, CHE-0215838)The FESEM acquisition was supported by the NSF (DBI-0116835)the VP for Research Office, and the TX Eng. Exp. Station. D. Liu and C. Zhong thank the supports of Natural Science Foundation of China (21136001, 21276008)National Key Basic Research Program of China (2013CB733503)D.L. also thanks the support of China Scholarship Council (201208110375) Beijing Higher Education Young EliteTeacher Project (YETP0486)
文摘With the aid of a postsynthetic metathesis method, an inert nitrogen-rich porphyrinic metal-organic framework can exhibit a high catalytic activity in one-pot deacetalization-Knoevenagel condensation reaction.
基金Authors are grateful for the support from National Key Research and Development Program of China(nos.2017YFA0206801 and 2018YFA0208600)National Natural Science Foundation of China(nos.21520102001 and 21871267)the Strategic Priority Research Program of the Chinese Academy of Sciences(no.XDB20000000).
文摘The judicious choice of metal clusters and organic building blocks leads to a wide variety of structures for metal–organic frameworks(MOFs).In this work,we demonstrated that relegating the symmetry of a building block can also lead to the proliferation of new MOF structures.Herein,a triangle building block was elongated with reduced symmetry for MOF construction,which gave rise to a novel(3,4,6)-connected idp(based on the definition of Reticular Chemistry Structure Resource,http://rcsr.net/)network(PFC-16)with mesopores and abundant open-metal sites.The framework is composed of the rarely observed tetrakis hexahedral cages,surrounding which are small cages arranged in sodalite topology.The relegated symmetry was required for this novel self-assembly.The obtained MOF with mesopores,a robust backbone,and abundant open-metal sites can incorporate functional species in the structure,which is representatively demonstrated by internalizing the photosensitizer zinc(II)phthalocyanine(ZnPc)and the modifying tumor-targeting molecule folic acid(FA)in PFC-16.The obtained composite FA-ZnPc@nano-PFC-16 shows excellent photodynamic therapy(PDT)efficiency for both in vitro and in vivo experiments,representing a promising candidate for cancer therapy.
