Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not r...Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not reliable, which means that the seismic design code cannot accurately define seismic design requirements for long-period structures. The near-field recordings in the main-shock of the Chi-Chi earthquake have a large signal-to-noise ratio （SNR）, which makes them suitable for studying the long-period acceleration response spectrum up to 20 sec. The acceleration response spectra from 246 stations within 120 km of the causative fault are statistically analyzed in this paper. The influence of distance and site conditions on long-period response spectrum is discussed, and the shapes of the amplification spectra are compared with the standard spectra specified in the seismic design code of China. Finally, suggestions for future revisions to the code are proposed.展开更多
In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are dif...In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are different from those of weak record numbers,which are interesting complements of the conclusions by Li and Yao[1].展开更多
Personal video recorders (PVRs) have altered the way users consume television (TV) content by allowing users to record programs and watch them at their convenience, overcoming the constraints of live broadcasting. How...Personal video recorders (PVRs) have altered the way users consume television (TV) content by allowing users to record programs and watch them at their convenience, overcoming the constraints of live broadcasting. However, standalone PVRs are limited by their individual storage capacities, restricting the number of programs they can store. While online catch-up TV services such as Hulu and Netflix mitigate this limitation by offering on-demand access to broadcast programs shortly after their initial broadcast, they require substantial storage and network resources, leading to significant infrastructural costs for service providers. To address these challenges, we propose a collaborative TV content recording system that leverages distributed PVRs, combining their storage into a virtual shared pool without additional costs. Our system aims to support all concurrent playback requests without service interruption while ensuring program availability comparable to that of local devices. The main contributions of our proposed system are fourfold. First, by sharing storage and upload bandwidth among PVRs, our system significantly expands the overall recording capacity and enables simultaneous recording of multiple programs without the physical constraints of standalone devices. Second, by utilizing erasure coding efficiently, our system reduces the storage space required for each program, allowing more programs to be recorded compared to traditional replication. Third, we propose an adaptive redundancy scheme to control the degree of redundancy of each program based on its evolving playback demand, ensuring high-quality playback by providing sufficient bandwidth for popular programs. Finally, we introduce a contribution-based incentive policy that encourages PVRs to actively participate by contributing resources, while discouraging excessive consumption of the combined storage pool. Through extensive experiments, we demonstrate the effectiveness of our proposed collaborative TV program recording system in terms of storage efficiency and performance.展开更多
To understand the complex dynamics of neural activity in the brain across various temporal and spatial scales,it is crucial to record intracortical multimodal neural activity by combining electrophysiological recordin...To understand the complex dynamics of neural activity in the brain across various temporal and spatial scales,it is crucial to record intracortical multimodal neural activity by combining electrophysiological recording and calcium imaging techniques.This poses significant constraints on the geometrical,mechanical,and optical properties of the electrodes.Here,transparent flexible graphene–ITO-based neural microelectrodes with small feature sizes are developed and validated for simultaneous electrophysiology recording and calcium imaging in the hippocampus of freely moving mice.A micro-etching technique and an oxygen plasma pre-treating method are introduced to facilitate large-area graphene transfer and establish stable low-impedance contacts between graphene and metals,leading to the batch production of high-quality microelectrodes with interconnect widths of 10μm and recording sites diameters of 20μm.These electrodes exhibit appropriate impedance and sufficient transparency in the field of view,enabling simultaneous recording of intracortical local field potentials and even action potentials along with calcium imaging in freely moving mice.Both types of electrophysiological signals are found to correlate with calcium activity.This proof-of-concept work demonstrates that transparent flexible graphene–ITO-based neural microelectrodes are promising tools for multimodal neuroscience research.展开更多
Precise and long-term electroanalysis at the single-cell level is crucial for the accurate diagnosis and monitoring of brain diseases.The reliable protection in areas outside the signal acquisition points at sharp ult...Precise and long-term electroanalysis at the single-cell level is crucial for the accurate diagnosis and monitoring of brain diseases.The reliable protection in areas outside the signal acquisition points at sharp ultramicroelectrode(UME)tips has a significant impact on the sensitivity,fidelity,and stability of intracellular neural signal recording.However,it is difficult for existing UMEs to achieve controllable exposure of the tip functional structure,which affects their ability to resist environmental interference and shield noise,resulting in unsatisfactory signal-to-noise ratio and signal fidelity of intracellular recordings.To address this issue,we chose a dense and electrochemically stable diamond-like carbon(DLC)film as the UME protection coating and developed a method to precisely control the exposed degree of the functional structure by directly fixed-point processing of the UME tip by the strong site-selectivity and good controllability of the atmospheric microplasma jet.By analyzing the interaction between the microplasma jet and the UME tip,as well as the changes in the removal length and microstructure of UME tips with processing time,the exposed tip length was precisely controlled down to the submicron scale.Biocompatibility experiments,electrochemical aging tests and real-time intracellular pH recording experiments have demonstrated that the DLC-UME with effective tip protection processed by microplasma jet has the potential to enable long-term detection of intracellular high-fidelity signals.展开更多
The National Strong Motion Observation Network System （NSMONS） of China is briefly introduced in this paper. The NSMONS consists of permanent free-field stations, special observation arrays, mobile observatories and...The National Strong Motion Observation Network System （NSMONS） of China is briefly introduced in this paper. The NSMONS consists of permanent free-field stations, special observation arrays, mobile observatories and a network management system. During the Wenchuan Earthquake, over 1,400 components of acceleration records were obtained from 460 permanent free-field stations and three arrays for topographical effect and structural response observation in the network system from the main shock, and over 20,000 components of acceleration records from strong aftershocks occurred before August 1, 2008 were also obtained by permanent free-field stations of the NSMONS and 59 mobile instruments quickly deployed after the main shock. The strong motion recordings from the main shock and strong aftershocks are summarized in this paper. In the ground motion recordings, there are over 560 components with peak ground acceleration （PGA） over 10 Gal, the largest being 957.7 Gal. The largest PGA recorded during the aftershock exceeds 300 Gal.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
On September 8, 2018, an M_S 5.9 earthquake struck Mojiang, a county in Yunnan Province, China. We collect near-field seismic recordings(epicentral distances less than 200 km) to relocate the mainshock and the aftersh...On September 8, 2018, an M_S 5.9 earthquake struck Mojiang, a county in Yunnan Province, China. We collect near-field seismic recordings(epicentral distances less than 200 km) to relocate the mainshock and the aftershocks within the first 60 hours to determine the focal mechanism solutions of the mainshock and some of the aftershocks and to invert for the finite-fault model of the mainshock.The focal mechanism solution of the mainshock and the relocation results of the aftershocks constrain the mainshock on a nearly vertical fault plane striking northeast and dipping to the southeast. The inversion of the finite-fault model reveals only a single slip asperity on the fault plane. The major slip is distributed above the initiation point, ～14 km wide along the down-dip direction and ～14 km long along the strike direction, with a maximal slip of ～22 cm at a depth of ～6 km. The focal mechanism solutions of the aftershocks show that most of the aftershocks are of the strike-slip type, a number of them are of the normal-slip type, and only a few of them are of the thrust-slip type.On average, strike-slip is dominant on the fault plane of the mainshock, as the focal mechanism solution of the mainshock suggests, but when examined in detail, slight thrust-slip appears on the southwest of the fault plane while an obvious part of normal-slip appears on the northeast, which is consistent with what the focal mechanism solutions of the aftershocks display. The multiple types of aftershock focal mechanism solutions and the slip details of the mainshock both suggest a complex tectonic setting, stress setting, or both. The intensity contours predicted exhibit a longer axis trending from northeast to southwest and a maximal intensity of Ⅷ around the epicenter and in the northwest.展开更多
DEAR EDITOR,The egg laying behavior of brood parasites is at the heart of studies on host co-evolution.Therefore,research on egg laying behavior can improve our understanding of brood parasitism and associated process...DEAR EDITOR,The egg laying behavior of brood parasites is at the heart of studies on host co-evolution.Therefore,research on egg laying behavior can improve our understanding of brood parasitism and associated processes.Over a seven year study period,we monitored 455 oriental reed warbler(Acrocephalus orientalis)nests during the egg laying period,250 of which were parasitized by common cuckoos(Cuculus canorus).We collected 53 clear videos of common cuckoo parasitism,analyzed all recorded parasitic behavior in detail.展开更多
AIM： To record calcium and potassium currents in acutely isolated smooth muscle cells of mesenteric arterial branches in rats. METHODS： Smooth muscle cells were freshly isolated by collagenase digest and mechanical ...AIM： To record calcium and potassium currents in acutely isolated smooth muscle cells of mesenteric arterial branches in rats. METHODS： Smooth muscle cells were freshly isolated by collagenase digest and mechanical trituration with polished pipettes. Patch clamp technique in whole-cell mode was employed to record calcium and potassium currents. RESULTS： The procedure dissociated smooth muscle cells without impairing the electrophysiological characteristics of the cells. The voltage-gated Ca^2＋ and potassium currents were successfully recorded using whole-cell patch clamp configuration. CONCLUSION： The method dissociates smooth muscle cells from rat mesenteric arterial branches. Voltage-gated channel currents can be recorded in this preparation.展开更多
A series of experiments are conducted to confirm whether the vectors calculated for an early section of a continuous non-invasive fetal electrocardiogram （fECG） recording can be directly applied to subsequent sectio...A series of experiments are conducted to confirm whether the vectors calculated for an early section of a continuous non-invasive fetal electrocardiogram （fECG） recording can be directly applied to subsequent sections in order to reduce the computation required for real-time monitoring. Our results suggest that it is generally feasible to apply the initial optimal maternal and fetal ECG combination vectors to extract the fECG and maternal ECG in subsequent recorded sections.展开更多
As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The ...As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.展开更多
In order to more effectively apply an artifact removal melhod in an online brain-computer interface （BCI） system, a new method based on canonical correlation analysis （CCA） and two-channel eleetroeneephalography ...In order to more effectively apply an artifact removal melhod in an online brain-computer interface （BCI） system, a new method based on canonical correlation analysis （CCA） and two-channel eleetroeneephalography （EEG） recordings to quickly remove ocular artifacts （OA） is proposed in this paper. Considering both the formation of EEG signals contaminated by OA and the spread of OA, vertical electrooculo~＇aphy （VEOG） was appropriately introduced in CCA, and the blind source separation （BSS~ method based on CCA was used in a new way during the OA removal process. Both experimental and comparison with ICA and SOBI results show that the new method with simple calculation and fast processing speed can effectively separate and remove OA using only two-channel EEG recordings, with retaining useful EEG signals. Hence, this method used in an online BCI system will be more effective.展开更多
By using wavelet analysis and the co-deduct method, under the condition that two explosions are supposed to have the same mechanism and strength, we separated the overlapped recordings successfully.
Many kinds of channel currents are especially weak and the background noise dominates in the patch clamp recordings. This makes the threshold detection fail during estimating of the transition probabilities. So direct...Many kinds of channel currents are especially weak and the background noise dominates in the patch clamp recordings. This makes the threshold detection fail during estimating of the transition probabilities. So direct fitting of the patch clamp recording, not of the histogram coming from the recordings, is a desirable way to estimate the transition probabilities. Iterative batch EM algorithm based on hidden markov model has been used in this field but which has the "curse of dimensionality" and besides cant keep tracking the varying of the parameters. A new on line sequential iterative one is proposed here, which needs fewer computational efforts and can adaptively keep tracking the varying of parameters. Simulations suggest its robust, effective and convenient.展开更多
The usefulness of telemedicine has been acknowledged because of coronavirus disease 2019,which highlighted it as a prominent and expedient method of delivering healthcare support while ensuring safety.1The implementat...The usefulness of telemedicine has been acknowledged because of coronavirus disease 2019,which highlighted it as a prominent and expedient method of delivering healthcare support while ensuring safety.1The implementation of telemedicine can be traced to nearly every corner of the globe,from advanced economies like the USA and Europe to the most remote African villages.Today,telemedicine is widely used in developed nations.展开更多
Chrysosplenium fallax Koldaeva,recently discovered and collected in Yanji,Jilin Province,repre-sents a newly recorded species of Saxifragaceae in China.This species,native to the Russian Far East,was first described a...Chrysosplenium fallax Koldaeva,recently discovered and collected in Yanji,Jilin Province,repre-sents a newly recorded species of Saxifragaceae in China.This species,native to the Russian Far East,was first described as a new species in 2021.Based on precise field investigations and specimen examination,we provide a comprehensive description of C.fallax and its seed micromorphology.Phylogenetic analysis based on chloroplast genomes of 45 Chrysosplenium species confirmed the systematic position of C.fallax in Chrysosplenium.Voucher specimens were deposited in the Herbarium of South-Central Minzu University(HSN).展开更多
Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specim...Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specimen,and geographical distribution of the species are described.The discovery of new records not only enriches the study of plant diversity in Vietnam,but also provides important information for biodiversity conservation and botanical research in the region.The voucher specimens are kept in the Herbarium of Kunming Institute of Botany,Chinese Academy of Sciences(KUN),Herbarium of Institute of Botany,Chinese Academy of Sciences(PE)and Herbarium of Guangxi Forestry Research Institute(GXFI).展开更多
We recorded continuous seismic noise close and around two wind parks with different geological site conditions in order to investigate the effects of wind turbines on seismic signals in the frequency interval between ...We recorded continuous seismic noise close and around two wind parks with different geological site conditions in order to investigate the effects of wind turbines on seismic signals in the frequency interval between 1 and 10 Hz. In wind park Fraureuth-Beiersdorf (5 turbines, 11 km south from Zwickau, Saxony), we used small seismic networks, with 3 to 5 stations for 1 - 2 weeks. In Heinde (2 turbines, close to Hildesheim, Lower Saxony), we recorded 1 week with one station around 1 km away from the wind turbines and some additional stations for several hours only. With the spectrogram analysis of the data, we clearly identify the diurnal variation on the spectral amplitude separately from the noise generated by the turbines. The turbine noise appears at certain frequency bands around 2.2, 2.7, 3.3, 4.5, 5.2 and 6.6 Hz. A linear relation between the spectral amplitudes of these frequency bands and the wind velocity or rotation velocity of the turbines is clearly identified. The seismic signals produced by the operation of the wind turbines are not peaks at single frequencies, but look more like frequency bands with increased noise amplitudes. They could be identified up to at least 10 km in the case of Fraureuth-Beiersdorf. These bands depend on numerous parameters, i.e. wind turbine height, weight and construction, number of turbines, geology, etc. In both wind parks we also recorded along profiles with increasing distances from the wind turbines. With the analysis of these data, we propose an amplitude attenuation model for the wind park Fraureuth-Beiersdorf to a distance of 9 km, and for Heinde to a distance of 4 km. The attenuation models for both wind parks are quite different, depending probably on the local geology and topography.展开更多
基金National Natural Science Foundation of China Under Grant No.40374017
文摘Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not reliable, which means that the seismic design code cannot accurately define seismic design requirements for long-period structures. The near-field recordings in the main-shock of the Chi-Chi earthquake have a large signal-to-noise ratio （SNR）, which makes them suitable for studying the long-period acceleration response spectrum up to 20 sec. The acceleration response spectra from 246 stations within 120 km of the causative fault are statistically analyzed in this paper. The influence of distance and site conditions on long-period response spectrum is discussed, and the shapes of the amplification spectra are compared with the standard spectra specified in the seismic design code of China. Finally, suggestions for future revisions to the code are proposed.
基金supported by the National Natural Science Foundation of China(Grant No.11671145)the Science and Technology Commission of Shanghai Municipality(Grant No.18dz2271000).
文摘In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are different from those of weak record numbers,which are interesting complements of the conclusions by Li and Yao[1].
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.2019R1A2C1002221 and RS-2023-00252186)Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(Nos.2021-0-00590,RS-2021-II210590Decentralized High Performance Consensus for Large-Scale Blockchains).
文摘Personal video recorders (PVRs) have altered the way users consume television (TV) content by allowing users to record programs and watch them at their convenience, overcoming the constraints of live broadcasting. However, standalone PVRs are limited by their individual storage capacities, restricting the number of programs they can store. While online catch-up TV services such as Hulu and Netflix mitigate this limitation by offering on-demand access to broadcast programs shortly after their initial broadcast, they require substantial storage and network resources, leading to significant infrastructural costs for service providers. To address these challenges, we propose a collaborative TV content recording system that leverages distributed PVRs, combining their storage into a virtual shared pool without additional costs. Our system aims to support all concurrent playback requests without service interruption while ensuring program availability comparable to that of local devices. The main contributions of our proposed system are fourfold. First, by sharing storage and upload bandwidth among PVRs, our system significantly expands the overall recording capacity and enables simultaneous recording of multiple programs without the physical constraints of standalone devices. Second, by utilizing erasure coding efficiently, our system reduces the storage space required for each program, allowing more programs to be recorded compared to traditional replication. Third, we propose an adaptive redundancy scheme to control the degree of redundancy of each program based on its evolving playback demand, ensuring high-quality playback by providing sufficient bandwidth for popular programs. Finally, we introduce a contribution-based incentive policy that encourages PVRs to actively participate by contributing resources, while discouraging excessive consumption of the combined storage pool. Through extensive experiments, we demonstrate the effectiveness of our proposed collaborative TV program recording system in terms of storage efficiency and performance.
基金support of the National Key R&D Program of China(2022YFF1202303 and 2023YFF1203702)NSFC-Guangdong Joint Fund(U20A6005)+2 种基金the National Natural Science Foundation of China(62071447)STI2030-Major Projects(2021ZD0200100)the Science and Technology Innovation Committee of Shenzhen Municipality(JCYJ20220818101611024).
文摘To understand the complex dynamics of neural activity in the brain across various temporal and spatial scales,it is crucial to record intracortical multimodal neural activity by combining electrophysiological recording and calcium imaging techniques.This poses significant constraints on the geometrical,mechanical,and optical properties of the electrodes.Here,transparent flexible graphene–ITO-based neural microelectrodes with small feature sizes are developed and validated for simultaneous electrophysiology recording and calcium imaging in the hippocampus of freely moving mice.A micro-etching technique and an oxygen plasma pre-treating method are introduced to facilitate large-area graphene transfer and establish stable low-impedance contacts between graphene and metals,leading to the batch production of high-quality microelectrodes with interconnect widths of 10μm and recording sites diameters of 20μm.These electrodes exhibit appropriate impedance and sufficient transparency in the field of view,enabling simultaneous recording of intracortical local field potentials and even action potentials along with calcium imaging in freely moving mice.Both types of electrophysiological signals are found to correlate with calcium activity.This proof-of-concept work demonstrates that transparent flexible graphene–ITO-based neural microelectrodes are promising tools for multimodal neuroscience research.
基金supported by the National Key R&D Program of China under grant 2022YFF120301the Fundamental Research Funds for the Central Universities,the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDA25040100,XDA25040200 and XDA25040300)+4 种基金the National Natural Science Foundation of China(No.42127807-03)Project supported by Shanghai Municipal Science and Technology Major Project(2021SHZDZX)Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400203)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(No.SL2023ZD205)SJTU Trans-med Award(No.21X010301627).
文摘Precise and long-term electroanalysis at the single-cell level is crucial for the accurate diagnosis and monitoring of brain diseases.The reliable protection in areas outside the signal acquisition points at sharp ultramicroelectrode(UME)tips has a significant impact on the sensitivity,fidelity,and stability of intracellular neural signal recording.However,it is difficult for existing UMEs to achieve controllable exposure of the tip functional structure,which affects their ability to resist environmental interference and shield noise,resulting in unsatisfactory signal-to-noise ratio and signal fidelity of intracellular recordings.To address this issue,we chose a dense and electrochemically stable diamond-like carbon(DLC)film as the UME protection coating and developed a method to precisely control the exposed degree of the functional structure by directly fixed-point processing of the UME tip by the strong site-selectivity and good controllability of the atmospheric microplasma jet.By analyzing the interaction between the microplasma jet and the UME tip,as well as the changes in the removal length and microstructure of UME tips with processing time,the exposed tip length was precisely controlled down to the submicron scale.Biocompatibility experiments,electrochemical aging tests and real-time intracellular pH recording experiments have demonstrated that the DLC-UME with effective tip protection processed by microplasma jet has the potential to enable long-term detection of intracellular high-fidelity signals.
基金NSFC Under Grant No. 90715038MOST of China Under Grant No. 2006BAC13B02
文摘The National Strong Motion Observation Network System （NSMONS） of China is briefly introduced in this paper. The NSMONS consists of permanent free-field stations, special observation arrays, mobile observatories and a network management system. During the Wenchuan Earthquake, over 1,400 components of acceleration records were obtained from 460 permanent free-field stations and three arrays for topographical effect and structural response observation in the network system from the main shock, and over 20,000 components of acceleration records from strong aftershocks occurred before August 1, 2008 were also obtained by permanent free-field stations of the NSMONS and 59 mobile instruments quickly deployed after the main shock. The strong motion recordings from the main shock and strong aftershocks are summarized in this paper. In the ground motion recordings, there are over 560 components with peak ground acceleration （PGA） over 10 Gal, the largest being 957.7 Gal. The largest PGA recorded during the aftershock exceeds 300 Gal.
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.
基金supported by the National Natural Science Foundation of China(project 41804088)the Special Fund of the Institute of Geophysics,China Earthquake Administration(project DQJB19B08)
文摘On September 8, 2018, an M_S 5.9 earthquake struck Mojiang, a county in Yunnan Province, China. We collect near-field seismic recordings(epicentral distances less than 200 km) to relocate the mainshock and the aftershocks within the first 60 hours to determine the focal mechanism solutions of the mainshock and some of the aftershocks and to invert for the finite-fault model of the mainshock.The focal mechanism solution of the mainshock and the relocation results of the aftershocks constrain the mainshock on a nearly vertical fault plane striking northeast and dipping to the southeast. The inversion of the finite-fault model reveals only a single slip asperity on the fault plane. The major slip is distributed above the initiation point, ～14 km wide along the down-dip direction and ～14 km long along the strike direction, with a maximal slip of ～22 cm at a depth of ～6 km. The focal mechanism solutions of the aftershocks show that most of the aftershocks are of the strike-slip type, a number of them are of the normal-slip type, and only a few of them are of the thrust-slip type.On average, strike-slip is dominant on the fault plane of the mainshock, as the focal mechanism solution of the mainshock suggests, but when examined in detail, slight thrust-slip appears on the southwest of the fault plane while an obvious part of normal-slip appears on the northeast, which is consistent with what the focal mechanism solutions of the aftershocks display. The multiple types of aftershock focal mechanism solutions and the slip details of the mainshock both suggest a complex tectonic setting, stress setting, or both. The intensity contours predicted exhibit a longer axis trending from northeast to southwest and a maximal intensity of Ⅷ around the epicenter and in the northwest.
基金This work was supported by the National Natural Science Foundation of China(31660617 and 31960105 to L.W.W.,31772453 and 31970427 to W.L.).L.W.W.was funded by the Initial Fund Key Laboratories of Guizhou Province(2011-4005)Joint Fund of the National Natural Science Foundation of China and the Karst Science Research Center of Guizhou Province(U1812401)。
文摘DEAR EDITOR,The egg laying behavior of brood parasites is at the heart of studies on host co-evolution.Therefore,research on egg laying behavior can improve our understanding of brood parasitism and associated processes.Over a seven year study period,we monitored 455 oriental reed warbler(Acrocephalus orientalis)nests during the egg laying period,250 of which were parasitized by common cuckoos(Cuculus canorus).We collected 53 clear videos of common cuckoo parasitism,analyzed all recorded parasitic behavior in detail.
文摘AIM： To record calcium and potassium currents in acutely isolated smooth muscle cells of mesenteric arterial branches in rats. METHODS： Smooth muscle cells were freshly isolated by collagenase digest and mechanical trituration with polished pipettes. Patch clamp technique in whole-cell mode was employed to record calcium and potassium currents. RESULTS： The procedure dissociated smooth muscle cells without impairing the electrophysiological characteristics of the cells. The voltage-gated Ca^2＋ and potassium currents were successfully recorded using whole-cell patch clamp configuration. CONCLUSION： The method dissociates smooth muscle cells from rat mesenteric arterial branches. Voltage-gated channel currents can be recorded in this preparation.
基金supported by the National Natural Science Foundation of China(Grant No.61271079)
文摘A series of experiments are conducted to confirm whether the vectors calculated for an early section of a continuous non-invasive fetal electrocardiogram （fECG） recording can be directly applied to subsequent sections in order to reduce the computation required for real-time monitoring. Our results suggest that it is generally feasible to apply the initial optimal maternal and fetal ECG combination vectors to extract the fECG and maternal ECG in subsequent recorded sections.
基金supported by the Meteorological Soft Science Project(Grant No.2023ZZXM29)the Natural Science Fund Project of Tianjin,China(Grant No.21JCYBJC00740)the Key Research and Development-Social Development Program of Jiangsu Province,China(Grant No.BE2021685).
文摘As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.
基金National Science Foundation of China grant number: 61172108,61139001 and 60872122+1 种基金Shanghai Dianji University Leading Academic Discipine Project grant number: 10xkf01
文摘In order to more effectively apply an artifact removal melhod in an online brain-computer interface （BCI） system, a new method based on canonical correlation analysis （CCA） and two-channel eleetroeneephalography （EEG） recordings to quickly remove ocular artifacts （OA） is proposed in this paper. Considering both the formation of EEG signals contaminated by OA and the spread of OA, vertical electrooculo~＇aphy （VEOG） was appropriately introduced in CCA, and the blind source separation （BSS~ method based on CCA was used in a new way during the OA removal process. Both experimental and comparison with ICA and SOBI results show that the new method with simple calculation and fast processing speed can effectively separate and remove OA using only two-channel EEG recordings, with retaining useful EEG signals. Hence, this method used in an online BCI system will be more effective.
基金This project was sponsored by the Joint Earthquake Science Foundation, CSB (No. 197010).
文摘By using wavelet analysis and the co-deduct method, under the condition that two explosions are supposed to have the same mechanism and strength, we separated the overlapped recordings successfully.
文摘Many kinds of channel currents are especially weak and the background noise dominates in the patch clamp recordings. This makes the threshold detection fail during estimating of the transition probabilities. So direct fitting of the patch clamp recording, not of the histogram coming from the recordings, is a desirable way to estimate the transition probabilities. Iterative batch EM algorithm based on hidden markov model has been used in this field but which has the "curse of dimensionality" and besides cant keep tracking the varying of the parameters. A new on line sequential iterative one is proposed here, which needs fewer computational efforts and can adaptively keep tracking the varying of parameters. Simulations suggest its robust, effective and convenient.
文摘The usefulness of telemedicine has been acknowledged because of coronavirus disease 2019,which highlighted it as a prominent and expedient method of delivering healthcare support while ensuring safety.1The implementation of telemedicine can be traced to nearly every corner of the globe,from advanced economies like the USA and Europe to the most remote African villages.Today,telemedicine is widely used in developed nations.
文摘Chrysosplenium fallax Koldaeva,recently discovered and collected in Yanji,Jilin Province,repre-sents a newly recorded species of Saxifragaceae in China.This species,native to the Russian Far East,was first described as a new species in 2021.Based on precise field investigations and specimen examination,we provide a comprehensive description of C.fallax and its seed micromorphology.Phylogenetic analysis based on chloroplast genomes of 45 Chrysosplenium species confirmed the systematic position of C.fallax in Chrysosplenium.Voucher specimens were deposited in the Herbarium of South-Central Minzu University(HSN).
文摘Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specimen,and geographical distribution of the species are described.The discovery of new records not only enriches the study of plant diversity in Vietnam,but also provides important information for biodiversity conservation and botanical research in the region.The voucher specimens are kept in the Herbarium of Kunming Institute of Botany,Chinese Academy of Sciences(KUN),Herbarium of Institute of Botany,Chinese Academy of Sciences(PE)and Herbarium of Guangxi Forestry Research Institute(GXFI).
文摘We recorded continuous seismic noise close and around two wind parks with different geological site conditions in order to investigate the effects of wind turbines on seismic signals in the frequency interval between 1 and 10 Hz. In wind park Fraureuth-Beiersdorf (5 turbines, 11 km south from Zwickau, Saxony), we used small seismic networks, with 3 to 5 stations for 1 - 2 weeks. In Heinde (2 turbines, close to Hildesheim, Lower Saxony), we recorded 1 week with one station around 1 km away from the wind turbines and some additional stations for several hours only. With the spectrogram analysis of the data, we clearly identify the diurnal variation on the spectral amplitude separately from the noise generated by the turbines. The turbine noise appears at certain frequency bands around 2.2, 2.7, 3.3, 4.5, 5.2 and 6.6 Hz. A linear relation between the spectral amplitudes of these frequency bands and the wind velocity or rotation velocity of the turbines is clearly identified. The seismic signals produced by the operation of the wind turbines are not peaks at single frequencies, but look more like frequency bands with increased noise amplitudes. They could be identified up to at least 10 km in the case of Fraureuth-Beiersdorf. These bands depend on numerous parameters, i.e. wind turbine height, weight and construction, number of turbines, geology, etc. In both wind parks we also recorded along profiles with increasing distances from the wind turbines. With the analysis of these data, we propose an amplitude attenuation model for the wind park Fraureuth-Beiersdorf to a distance of 9 km, and for Heinde to a distance of 4 km. The attenuation models for both wind parks are quite different, depending probably on the local geology and topography.
