The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding en...The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding energies. We find that the energy back shift EI shows complicated behavior and depends on the type of the nucleus, even-even, odd mass, and odd-odd. The spin cut-off factor has also been investigated for nuclei mentioned above. The results are compared with the previous results and different experimental data on level densities.展开更多
The spin cut-off parameter of the nuclear level density and effective moment of inertia for a large number of nuclei have been determined from analysis of the experimental data on S-wave neutron resonances and spins o...The spin cut-off parameter of the nuclear level density and effective moment of inertia for a large number of nuclei have been determined from analysis of the experimental data on S-wave neutron resonances and spins of lowlying levels. Contrary to claims made before, it is shown the spin cut-off parameter differs considerably from their corresponding rigid body values, and the energy dependence of the effective moment of inertia confirms the interacting fermion model prediction.展开更多
Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological imaging.Multiplexing metalenses...Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological imaging.Multiplexing metalenses present promising candidates for achieving this functionality.However,current multiplexing meta-lenses lack spectral modulation,and crosstalk between different wavelengths hampers the imaging quality,especilly for biological samples requiring precise wavelength specificity.Here,we experimentally demonstrate the nonlocal Huygens'meta-lens for high-quality-factor spin-multiplexing imaging.Quasi-bound states in the continuum(q-BlCs)are excited to provide a high quality factor of 90 and incident-angle dependence.The generalized Kerker condition,driven by Fano-like interactions between q-BIC and in-plane Mie resonances,breaks the radiation symmetry,resulting in a transmission peak with a geometric phase for polarization-converted light,while unconverted light exhibits a transmission dip without a geometric phase.Enhanced polarization conversion efficiency of 65%is achieved,accompanied by a minimal unconverted value,surpassing the theoretical limit of traditional thin nonlocal metasurfaces.Leveraging these effects,the output polarization-converted state exhibits an efficient wavelengthselective focusing phase profle.The unconverted counterpart serves as an effective spatial frequency filter based on incident-angular dispersion,passing high-frequency edge details.Bright-field imaging and edge detection are thus presented under two output spin states.This work provides a versatile framework for nonlocal metasurfaces,boosting biomedical imaging and sensing applications.展开更多
The integration of multiple chromophore units into a single molecule is expected to improve the performance of photon upconversion based on triplet−triplet annihilation(TTA-UC)that can convert low energy photons to hi...The integration of multiple chromophore units into a single molecule is expected to improve the performance of photon upconversion based on triplet−triplet annihilation(TTA-UC)that can convert low energy photons to higher energy photons at low excitation intensity.In this study,a macrocyclic parallel dimer of 9,10-diphenylanthracene(DPA)with a precisely parallel orientation,named MPD-2,is synthesized,and its TTAUC properties are investigated.MPD-2 shows a green-to-blue TTA-UC emission in the presence of a triplet sensitizer,platinum octaethylporphyrin(PtOEP).Compared to monomeric DPA,MPD-2 results in an enhancement of the spin statistical factor of TTA and a decrease in the excitation light intensity due to the intramolecular TTA process.The obtained structure−property relationship provides important information for the further improvement of TTA-UC properties.展开更多
文摘The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding energies. We find that the energy back shift EI shows complicated behavior and depends on the type of the nucleus, even-even, odd mass, and odd-odd. The spin cut-off factor has also been investigated for nuclei mentioned above. The results are compared with the previous results and different experimental data on level densities.
文摘The spin cut-off parameter of the nuclear level density and effective moment of inertia for a large number of nuclei have been determined from analysis of the experimental data on S-wave neutron resonances and spins of lowlying levels. Contrary to claims made before, it is shown the spin cut-off parameter differs considerably from their corresponding rigid body values, and the energy dependence of the effective moment of inertia confirms the interacting fermion model prediction.
基金supported by the University Grants Committee/Research Grants Council of the Hong Kong Special Administrative Region,China[Project No.AoE/P-502/20,CRF Project:C5031-22G,GRF Project:CityU15303521,CityU11305223,CityU11300224]City University of Hong Kong[Project No.9380131 and 7005867]+3 种基金National Natural Science Foundation of China[Grant No.62375232]S.X.acknowledges financial support from National Natural Science Foundation of China(Grant Nos.62125501,and 6233000076)Fundamental Research Funds for the Central Universities(Grant No.2022FRRK030004)Shenzhen Fundamental Research Projects(Grant Nos.JCYJ20220818102218040).
文摘Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological imaging.Multiplexing metalenses present promising candidates for achieving this functionality.However,current multiplexing meta-lenses lack spectral modulation,and crosstalk between different wavelengths hampers the imaging quality,especilly for biological samples requiring precise wavelength specificity.Here,we experimentally demonstrate the nonlocal Huygens'meta-lens for high-quality-factor spin-multiplexing imaging.Quasi-bound states in the continuum(q-BlCs)are excited to provide a high quality factor of 90 and incident-angle dependence.The generalized Kerker condition,driven by Fano-like interactions between q-BIC and in-plane Mie resonances,breaks the radiation symmetry,resulting in a transmission peak with a geometric phase for polarization-converted light,while unconverted light exhibits a transmission dip without a geometric phase.Enhanced polarization conversion efficiency of 65%is achieved,accompanied by a minimal unconverted value,surpassing the theoretical limit of traditional thin nonlocal metasurfaces.Leveraging these effects,the output polarization-converted state exhibits an efficient wavelengthselective focusing phase profle.The unconverted counterpart serves as an effective spatial frequency filter based on incident-angular dispersion,passing high-frequency edge details.Bright-field imaging and edge detection are thus presented under two output spin states.This work provides a versatile framework for nonlocal metasurfaces,boosting biomedical imaging and sensing applications.
基金supported by the JST START(JPMJSF2303)JSPS KAKENHI(JP23H00304,JP22KF0295,JP23KJ1717)+1 种基金Kyushu University Platform of Inter-/Transdisciplinary Energy Research(Q-PIT)through its“Module-Research Program”Kyushu University Integrated Initiative for Designing Future Society.
文摘The integration of multiple chromophore units into a single molecule is expected to improve the performance of photon upconversion based on triplet−triplet annihilation(TTA-UC)that can convert low energy photons to higher energy photons at low excitation intensity.In this study,a macrocyclic parallel dimer of 9,10-diphenylanthracene(DPA)with a precisely parallel orientation,named MPD-2,is synthesized,and its TTAUC properties are investigated.MPD-2 shows a green-to-blue TTA-UC emission in the presence of a triplet sensitizer,platinum octaethylporphyrin(PtOEP).Compared to monomeric DPA,MPD-2 results in an enhancement of the spin statistical factor of TTA and a decrease in the excitation light intensity due to the intramolecular TTA process.The obtained structure−property relationship provides important information for the further improvement of TTA-UC properties.
