Metasurfaces enable the design of optical elements by engineering the wavefront of light at the subwavelength scale.Due to their ultrathin and compact characteristics,metasurfaces possess great potential to integrate ...Metasurfaces enable the design of optical elements by engineering the wavefront of light at the subwavelength scale.Due to their ultrathin and compact characteristics,metasurfaces possess great potential to integrate multiple functions in optoelectronic systems for optical device miniaturisation.However,current research based on multiplexing in the 2D plane has not fully utilised the capabilities of metasurfaces for multi-tasking applications.Here,we demonstrate a 3D-integrated metasurface device by stacking a hologram metasurface on a monolithic Fabry–Pérot cavity-based colour filter microarray to simultaneously achieve low-crosstalk,polarisation-independent,high-efficiency,full-colour holography,and microprint.The dual functions of the device outline a novel scheme for data recording,security encryption,colour displays,and information processing.Our 3D integration concept can be extended to achieve multi-tasking flat optical systems by including a variety of functional metasurface layers,such as polarizers,metalenses,and others.展开更多
Local site conditions play an important role in the effective application of strong motion recordings.In the China National Strong Motion Observation Network System（NSMONS）,some of the stations do not provide boreho...Local site conditions play an important role in the effective application of strong motion recordings.In the China National Strong Motion Observation Network System（NSMONS）,some of the stations do not provide borehole information,and correspondingly,do not assign the site classes yet.In this paper,site classification methodologies for free-field strong motion stations are reviewed and the limitations and uncertainties of the horizontal-to-vertical spectral ratio（HVSR） methods are discussed.Then,a new method for site classification based on the entropy weight theory is proposed.The proposed method avoids the head or tail joggle phenomenon by providing the objective and subjective weights.The method was applied to aftershock recordings from the 2008 Wenchuan earthquake,and 54 free-field NSMONS stations were selected for site classification and the mean HVSRs were calculated.The results show that the improved HVSR method proposed in this paper has a higher success rate and could be adopted in NSMONS.展开更多
Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after...Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after the principle of holography was first proposed. However, these systems, called conventional 2-axis holography, still have essential issues for commercialization of products. Collinear HDSS, in which the information and reference beams are modulated co-axially by the same spatial light modulator （SLM）, as a new read/write method for HDSS are very promising. With this unique configuration, the optical pickup can be designed as small as DVDs, and can be placed on one side of the recording media （disc）. In the disc structure, the preformatted reflective layer is used for the focus/tracking servo and reading address information, and a dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density. As servo technologies are being introduced to control the objective lens to be maintained precisely to the disc in the recording and reconstructing process, a vibration isolator is no longer necessary. Collinear holography can produce a small, practical HDSS more easily than conventional 2-axis holography. In this paper, we introduced the principle of the collinear holography and its media structure of disc. Some results of experimental and theoretical studies suggest that it is a very effective method. We also discussed some methods to increase the recording density and data transfer rates of collinear holography.展开更多
The fall armyworm Spodoptera frugiperda is a worldwide serious agricultural pest,and recently invaded South China.Sex pheromone can be employed to monitor its population dynamics accurately in the field.However,the ph...The fall armyworm Spodoptera frugiperda is a worldwide serious agricultural pest,and recently invaded South China.Sex pheromone can be employed to monitor its population dynamics accurately in the field.However,the pheromone components previously reported by testing different geographic populations and strains are not consistent.On the basis of confirming that the S.frugiperda population from Yunnan Province belonged to the com strain,we analyzed the potential sex pheromone components in the pheromone gland extracts of females using gas chromatography coupled with electroan-tennographic detection(GC-EAD),gas chromatography coupled with mass spectrometry(GC-MS)and electroantennography(EAG).The results show that(Z)-9-tetradecenal acetate(Z9-14:Ac),(Z)-11-hexadecenyl acetate(Z11-16:Ac),(Z)-7-dodecenyl acetate(Z7-12:Ac)or(E)-7-dodecenyl acetate(E7-12:Ac)with a ratio of 100:15.8:3.9 induced EAD responses to varying degrees:Z9-14:Ac elicited a strong EAD response,Z7-12:Ac or E7-12:Ac elicited a small but clear EAD response,while Z11-16:Ac elicited a weak EAD response.Further single sensillum recording(SSR)showed that Z9-14:Ac and Z7-12:Ac induced dose-dependent activities in two types(A and B)of sensilla in male antennae,respectively,while the sensilla in response to E7-12:Ac and Z11-16:Ac was not recorded.Finally,wind tunnel tests reveal that Z9-14:Ac and Z7-12:Ac are two principal sex pheromone components of the tested population.展开更多
Stress sensing is the basis of human-machine interface,biomedical engineering,and mechanical structure detection systems.Stress sensing based on mechanoluminescence(ML)shows significant advantages of distributed detec...Stress sensing is the basis of human-machine interface,biomedical engineering,and mechanical structure detection systems.Stress sensing based on mechanoluminescence(ML)shows significant advantages of distributed detection and remote response to mechanical stimuli and is thus expected to be a key technology of next-generation tactile sensors and stress recorders.However,the instantaneous photon emission in ML materials generally requires real-time recording with a photodetector,thus limiting their application fields to real-time stress sensing.In this paper,we report a force-induced charge carrier storage(FICS)effect in deep-trap ML materials,which enables storage of the applied mechanical energy in deep traps and then release of the stored energy as photon emission under thermal stimulation.The FICS effect was confirmed in five ML materials with piezoelectric structures,efficient emission centres and deep trap distributions,and its mechanism was investigated through detailed spectroscopic characterizations.Furthermore,we demonstrated three applications of the FICS effect in electronic signature recording,falling point monitoring and vehicle collision recording,which exhibited outstanding advantages of distributed recording,longterm storage,and no need for a continuous power supply.The FICS effect reported in this paper provides not only a breakthrough for ML materials in the field of stress recording but also a new idea for developing mechanical energy storage and conversion systems.展开更多
The pain-relieving effect of acupuncture is known to involve primary afferent nerves(PANs) via their roles in signal transmission to the CNS.Using single-unit recording in rats,we characterized the generation and tran...The pain-relieving effect of acupuncture is known to involve primary afferent nerves(PANs) via their roles in signal transmission to the CNS.Using single-unit recording in rats,we characterized the generation and transmission of electrical signals in Aβ and Aδ fibers induced by acupuncture-like stimuli.Acupuncture-like signals were elicited in PANs using three techniques:manual acupuncture(MAc),emulated acupuncture(EAc),and electro-acupuncture(EA)-like peripheral electrical stimulation(PES).The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz,respectively.The frequency of discharges in PANs was correlated with the frequency of PES.The highest discharge frequency was 246 Hz in Aβ fibers and 180 Hz in Aδ fibers.Therefore,EA in a dense-disperse mode(at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc.Frequencies of EA output>250 Hz appear to be obsolete for pain relief.展开更多
The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation （i-LTP）, points to f...The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation （i-LTP）, points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-l-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory post- synaptic potentials （fEPSPs） on CA1 hippocampal neurons in peri-infarct regions of the endothelin-l-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dam- pened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synap- tic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.展开更多
基金the financial support of the National Natural Science Foundation of China under contract nos.51722503,51621004 and 11574078.
文摘Metasurfaces enable the design of optical elements by engineering the wavefront of light at the subwavelength scale.Due to their ultrathin and compact characteristics,metasurfaces possess great potential to integrate multiple functions in optoelectronic systems for optical device miniaturisation.However,current research based on multiplexing in the 2D plane has not fully utilised the capabilities of metasurfaces for multi-tasking applications.Here,we demonstrate a 3D-integrated metasurface device by stacking a hologram metasurface on a monolithic Fabry–Pérot cavity-based colour filter microarray to simultaneously achieve low-crosstalk,polarisation-independent,high-efficiency,full-colour holography,and microprint.The dual functions of the device outline a novel scheme for data recording,security encryption,colour displays,and information processing.Our 3D integration concept can be extended to achieve multi-tasking flat optical systems by including a variety of functional metasurface layers,such as polarizers,metalenses,and others.
基金National Key Technology R&D Program Under Grant No.2009BAK55B05Nonprofit Industry Research Project of CEA Under Grant No.201108003Science Foundation of Institute of Engineering Mechanics,CEA Under Grant No.2010C01
文摘Local site conditions play an important role in the effective application of strong motion recordings.In the China National Strong Motion Observation Network System（NSMONS）,some of the stations do not provide borehole information,and correspondingly,do not assign the site classes yet.In this paper,site classification methodologies for free-field strong motion stations are reviewed and the limitations and uncertainties of the horizontal-to-vertical spectral ratio（HVSR） methods are discussed.Then,a new method for site classification based on the entropy weight theory is proposed.The proposed method avoids the head or tail joggle phenomenon by providing the objective and subjective weights.The method was applied to aftershock recordings from the 2008 Wenchuan earthquake,and 54 free-field NSMONS stations were selected for site classification and the mean HVSRs were calculated.The results show that the improved HVSR method proposed in this paper has a higher success rate and could be adopted in NSMONS.
文摘Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after the principle of holography was first proposed. However, these systems, called conventional 2-axis holography, still have essential issues for commercialization of products. Collinear HDSS, in which the information and reference beams are modulated co-axially by the same spatial light modulator （SLM）, as a new read/write method for HDSS are very promising. With this unique configuration, the optical pickup can be designed as small as DVDs, and can be placed on one side of the recording media （disc）. In the disc structure, the preformatted reflective layer is used for the focus/tracking servo and reading address information, and a dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density. As servo technologies are being introduced to control the objective lens to be maintained precisely to the disc in the recording and reconstructing process, a vibration isolator is no longer necessary. Collinear holography can produce a small, practical HDSS more easily than conventional 2-axis holography. In this paper, we introduced the principle of the collinear holography and its media structure of disc. Some results of experimental and theoretical studies suggest that it is a very effective method. We also discussed some methods to increase the recording density and data transfer rates of collinear holography.
基金This work was supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.KJZDSW-L07)the National Natural Science Foundation of China(Grant No.31830088,31772528).
文摘The fall armyworm Spodoptera frugiperda is a worldwide serious agricultural pest,and recently invaded South China.Sex pheromone can be employed to monitor its population dynamics accurately in the field.However,the pheromone components previously reported by testing different geographic populations and strains are not consistent.On the basis of confirming that the S.frugiperda population from Yunnan Province belonged to the com strain,we analyzed the potential sex pheromone components in the pheromone gland extracts of females using gas chromatography coupled with electroan-tennographic detection(GC-EAD),gas chromatography coupled with mass spectrometry(GC-MS)and electroantennography(EAG).The results show that(Z)-9-tetradecenal acetate(Z9-14:Ac),(Z)-11-hexadecenyl acetate(Z11-16:Ac),(Z)-7-dodecenyl acetate(Z7-12:Ac)or(E)-7-dodecenyl acetate(E7-12:Ac)with a ratio of 100:15.8:3.9 induced EAD responses to varying degrees:Z9-14:Ac elicited a strong EAD response,Z7-12:Ac or E7-12:Ac elicited a small but clear EAD response,while Z11-16:Ac elicited a weak EAD response.Further single sensillum recording(SSR)showed that Z9-14:Ac and Z7-12:Ac induced dose-dependent activities in two types(A and B)of sensilla in male antennae,respectively,while the sensilla in response to E7-12:Ac and Z11-16:Ac was not recorded.Finally,wind tunnel tests reveal that Z9-14:Ac and Z7-12:Ac are two principal sex pheromone components of the tested population.
基金financially supported by the National Key Research and Development Programme(Nos.2017YFB0404300,2017YFB0404301)the National Natural Science Foundation of China(Nos.51872247,51832005,11804255)+1 种基金the Natural Science Foundation of Fujian Province(No.2018J01080)the Young Elite Scientists Sponsorship Programme by China Association for Science and Technology(No.2018QNRC001).
文摘Stress sensing is the basis of human-machine interface,biomedical engineering,and mechanical structure detection systems.Stress sensing based on mechanoluminescence(ML)shows significant advantages of distributed detection and remote response to mechanical stimuli and is thus expected to be a key technology of next-generation tactile sensors and stress recorders.However,the instantaneous photon emission in ML materials generally requires real-time recording with a photodetector,thus limiting their application fields to real-time stress sensing.In this paper,we report a force-induced charge carrier storage(FICS)effect in deep-trap ML materials,which enables storage of the applied mechanical energy in deep traps and then release of the stored energy as photon emission under thermal stimulation.The FICS effect was confirmed in five ML materials with piezoelectric structures,efficient emission centres and deep trap distributions,and its mechanism was investigated through detailed spectroscopic characterizations.Furthermore,we demonstrated three applications of the FICS effect in electronic signature recording,falling point monitoring and vehicle collision recording,which exhibited outstanding advantages of distributed recording,longterm storage,and no need for a continuous power supply.The FICS effect reported in this paper provides not only a breakthrough for ML materials in the field of stress recording but also a new idea for developing mechanical energy storage and conversion systems.
基金supported by the National Key Research and Development Program of the Ministry of Science and Technology,China (2016YFC0105501,2019YFC1712104 and 2016YFF0202802)the National Natural Science Foundation of China (81974169, 81671085 and 61527815)。
文摘The pain-relieving effect of acupuncture is known to involve primary afferent nerves(PANs) via their roles in signal transmission to the CNS.Using single-unit recording in rats,we characterized the generation and transmission of electrical signals in Aβ and Aδ fibers induced by acupuncture-like stimuli.Acupuncture-like signals were elicited in PANs using three techniques:manual acupuncture(MAc),emulated acupuncture(EAc),and electro-acupuncture(EA)-like peripheral electrical stimulation(PES).The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz,respectively.The frequency of discharges in PANs was correlated with the frequency of PES.The highest discharge frequency was 246 Hz in Aβ fibers and 180 Hz in Aδ fibers.Therefore,EA in a dense-disperse mode(at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc.Frequencies of EA output>250 Hz appear to be obsolete for pain relief.
基金supported by Major State Basic Research Program of China(Grant No.2013CB733801)
文摘The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation （i-LTP）, points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-l-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory post- synaptic potentials （fEPSPs） on CA1 hippocampal neurons in peri-infarct regions of the endothelin-l-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dam- pened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synap- tic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.
