Hyperspectral imaging(HSI)is a powerful tool widely used for various scientific and industrial applications due to its ability to provide rich spatiospectral information.However,in exchange for multiplex spectral info...Hyperspectral imaging(HSI)is a powerful tool widely used for various scientific and industrial applications due to its ability to provide rich spatiospectral information.However,in exchange for multiplex spectral information,its image acquisition rate is lower than that of conventional imaging,with up to a few colors.In particular,HSI in the infrared region and using nonlinear optical processes is impractically slow because the three-dimensional(3D)data cube must be scanned in a point-by-point manner.In this study,we demonstrate a framework to improve the spectral image acquisition rate of HSI by integrating time-domain HSI and compressed sensing.Specifically,we simulated broadband coherent Raman imaging at a record high frame rate of 25 frames per second(fps)with 100 pixels×100 pixels,which is 10×faster than that of previous work,based on an experimentally feasible sampling scheme utilizing 3D Lissajous scanning.展开更多
The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sit...The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions.Here,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of acidity.SAPO-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°C.In situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in olefins.The tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.展开更多
Broadband Raman spectroscopy(detection bandwidth>1000 cm^(−1))is a valuable and widely used tool for understanding samples via label-free measurements of their molecular vibrations.Two important Raman spectral regi...Broadband Raman spectroscopy(detection bandwidth>1000 cm^(−1))is a valuable and widely used tool for understanding samples via label-free measurements of their molecular vibrations.Two important Raman spectral regions are the chemically specific“fingerprint”(200 to 1800 cm^(−1))and“low-frequency”or“terahertz”(THz)(<200 cm^(−1);<6 THz)regions,which mostly contain intramolecular and intermolecular vibrations,respectively.These two regions are highly complementary;broadband simultaneous measurement of both regions can provide a big picture comprising information about molecular structures and interactions.Although techniques for acquiring broadband Raman spectra covering both regions have been demonstrated,these methods tend to have spectral acquisition rates<10 spectra∕s,prohibiting high-speed applications,such as Raman imaging or vibrational detection of transient phenomena.Here,we demonstrate a single-laser method for ultrafast(24,000 spectra∕s)broadband Raman spectroscopy covering both THz and fingerprint regions.This is achieved by simultaneous detection of Sagnac-enhanced impulsive stimulated Raman scattering(SE-ISRS;THz-sensitive)and Fourier-transform coherent anti-Stokes Raman scattering(FT-CARS;fingerprint-sensitive).With dual-detection impulsive vibrational spectroscopy,the SE-ISRS signal shows a>500×enhancement of<6.5 THz sensitivity compared with that of FT-CARS,and the FT-CARS signal shows a>10×enhancement of fingerprint sensitivity above 1000 cm^(−1)compared with that of SE-ISRS.展开更多
基金supported by JST PRESTO(Grant No.JPMJPR1878)JST FOREST(Grant No.21470594)+3 种基金JSPS Grant-in-Aid for Young Scientists(20K15227)Grant-in-Aid for Scientific Research(B)(Grant No.22538379)Grant-inAid for JSPS Fellows(Grant No.21J11484)JSPS Core-toCore Program,White Rock Foundation,Nakatani Foundation,and Ogasawara Foundation for the Promotion of Science and Engineering.
文摘Hyperspectral imaging(HSI)is a powerful tool widely used for various scientific and industrial applications due to its ability to provide rich spatiospectral information.However,in exchange for multiplex spectral information,its image acquisition rate is lower than that of conventional imaging,with up to a few colors.In particular,HSI in the infrared region and using nonlinear optical processes is impractically slow because the three-dimensional(3D)data cube must be scanned in a point-by-point manner.In this study,we demonstrate a framework to improve the spectral image acquisition rate of HSI by integrating time-domain HSI and compressed sensing.Specifically,we simulated broadband coherent Raman imaging at a record high frame rate of 25 frames per second(fps)with 100 pixels×100 pixels,which is 10×faster than that of previous work,based on an experimentally feasible sampling scheme utilizing 3D Lissajous scanning.
基金University of Manchester,the National Natural Science Foundation of China and BNLMS for funding,and the EPSRC for funding of the EPSRC National EPR Facility at Manchester(EP/W014532/1 and EP/X034623/1)We are grateful to the STFC/ISIS Facility and Diamond Light Source for access to the beamlines TOSCA/MAPS,and I11/B18/B22,respectively+8 种基金We are grateful to the STFC/ISIS Facility and Diamond Light Source for access to the beamlines TOSCA/MAPS,and I11/B18/B22,respectivelyWe acknowledge the UK catalysis Hub Block Allocation Group(BAG)Programme Mode Application for provision of beamtime at B18 for collection of the data presented in this work and the initial discussion of the dataThe UK Catalysis Hub is kindly thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC grant:EP/R026939,EP/R026815,EP/R026645,EP/R027129 and EP/M013219(biocatalysis)We acknowledge the support of The University of Manchester's Dalton Cumbrian Facility(DCF),a partner in the National Nuclear User FacilityWe recognise Dr.R.Edge for the assistance during the 60Co-irradiation processesWe thank M.Kibble for help at ISIS beamlinesTEM access was supported by the Henry Royce Institute for Advanced Materials,funded through EPSRC grants EP/R00661X,EP/S019367,EP/P025021 and EP/P025498Zhaodong Zhu thanks the President's Doctoral Scholar award of University of Manchester for fundingMeng He and Lutong Shan thank the China Scholarship Council(CSC)for funding.
文摘The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions.Here,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of acidity.SAPO-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°C.In situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in olefins.The tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.
基金supported by JST PRESTO (JPMJPR1878)JSPS Grant-in-Aid for Young Scientists (20K15227)+4 种基金Grant-in-Aid for JSPS Fellows (19F19805 and 21J15001)JSPS Core-to-Core ProgramWhite Rock FoundationNakatani FoundationOgasawara Foundation for the Promotion of Science and Engineering
文摘Broadband Raman spectroscopy(detection bandwidth>1000 cm^(−1))is a valuable and widely used tool for understanding samples via label-free measurements of their molecular vibrations.Two important Raman spectral regions are the chemically specific“fingerprint”(200 to 1800 cm^(−1))and“low-frequency”or“terahertz”(THz)(<200 cm^(−1);<6 THz)regions,which mostly contain intramolecular and intermolecular vibrations,respectively.These two regions are highly complementary;broadband simultaneous measurement of both regions can provide a big picture comprising information about molecular structures and interactions.Although techniques for acquiring broadband Raman spectra covering both regions have been demonstrated,these methods tend to have spectral acquisition rates<10 spectra∕s,prohibiting high-speed applications,such as Raman imaging or vibrational detection of transient phenomena.Here,we demonstrate a single-laser method for ultrafast(24,000 spectra∕s)broadband Raman spectroscopy covering both THz and fingerprint regions.This is achieved by simultaneous detection of Sagnac-enhanced impulsive stimulated Raman scattering(SE-ISRS;THz-sensitive)and Fourier-transform coherent anti-Stokes Raman scattering(FT-CARS;fingerprint-sensitive).With dual-detection impulsive vibrational spectroscopy,the SE-ISRS signal shows a>500×enhancement of<6.5 THz sensitivity compared with that of FT-CARS,and the FT-CARS signal shows a>10×enhancement of fingerprint sensitivity above 1000 cm^(−1)compared with that of SE-ISRS.
