The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(...The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(GEP).Based on statistical reasoning,individual models were developed for two topographies:free-face and gently sloping ground.Along with a comparison with conventional approaches for predicting the Dh,four additional regression-based soft computing models,i.e.Gaussian process regression(GPR),relevance vector machine(RVM),sequential minimal optimization regression(SMOR),and M5-tree,were developed and compared with the GEP model.The results indicate that the GEP models predict Dh with less bias,as evidenced by the root mean square error(RMSE)and mean absolute error(MAE)for training(i.e.1.092 and 0.815;and 0.643 and 0.526)and for testing(i.e.0.89 and 0.705;and 0.773 and 0.573)in free-face and gently sloping ground topographies,respectively.The overall performance for the free-face topology was ranked as follows:GEP>RVM>M5-tree>GPR>SMOR,with a total score of 40,32,24,15,and 10,respectively.For the gently sloping condition,the performance was ranked as follows:GEP>RVM>GPR>M5-tree>SMOR with a total score of 40,32,21,19,and 8,respectively.Finally,the results of the sensitivity analysis showed that for both free-face and gently sloping ground,the liquefiable layer thickness(T_(15))was the major parameter with percentage deterioration(%D)value of 99.15 and 90.72,respectively.展开更多
The rock series, rock types and Sr-Nd isotopic dating of the Cenozoicvolcanic rocks in the South China Sea are similar to those in its vicinity. On the basis of thespreading age of the South China Sea, the Cenozoic vo...The rock series, rock types and Sr-Nd isotopic dating of the Cenozoicvolcanic rocks in the South China Sea are similar to those in its vicinity. On the basis of thespreading age of the South China Sea, the Cenozoic volcanic rocks are divided into three stages: thepre-spreading stage, the spreading stage and the post-spreading stage. The deep processcharacteristics of the asthenosphere and lithosphere may be inferred from the study on primarybasaltic magma. The top layers of the asthenosphere both in the spreading stage and in thepre-spreading stage are closer to the earth surface than that in the post-spreading stage. From thepre-spreading stage to the spreading stage, the top layer of the asthenosphere decreased in depth,while the amount of interstitial partial melts increased. The evolution of the primary basalticmagma shows a progressive evolution sequence of the rifting volcanism and a faster lithosphericspreading velocity. From the spreading stage to the post-spreading stage, the top layer of theasthenosphere gradually increased in depth, but the amount of interstitial partial melts decreased.The evolution of primary basaltic magma shows a retrogressive evolution sequence of the riftingvolcanism and a gradual decrease in the lithospheric spreading velocity. The depth recognized by thestudy on the Cenozoic volcanism demonstrates the deep environment for the formation and evolutionof the South China Sea.展开更多
With processing and interpretation of 25 000 km full-coverage multibeam swath data fromthe eastern South China Sea, it is found that NE-trending and NW-trending linear morphological features such as scarps, horsts and...With processing and interpretation of 25 000 km full-coverage multibeam swath data fromthe eastern South China Sea, it is found that NE-trending and NW-trending linear morphological features such as scarps, horsts and grabens, govern the central part (14°-17° N) of eastern subbasin. Compared with reflection seismic profiles, these NE-trending linear morpho-structures are considered to be the representation of basement structures on seabed and can be divided into three linear structural zones. The trend of the central zone is NE45°-50° occurring around extinct spreading center, the trend of the second zone is NE70° - 78° on both sides of the central one and the trend of the third zone is about NE60° just on the north of the second one. These three NE-trending linear zones are formed in late-stage NW - SE-trending seafloor spreading of the eastern subbasin along NW-trending linear faults, and respectively correspond to three spreading episodes: 17.0- 19.0 Ma (5d-5e), 19.0 - 21.0 Ma (5e-6a) and 21.0 - 24.2 Ma (6a-6c) based on the contrast of morpho-structures to magnetic lineation anomalies.展开更多
The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the wid...The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features,their treatment usually lacks spatiotemporal variation.Here,we propose a stochastic individual dynamical(SID)model to mimic the random and heterogeneous nature of epidemic propagation.The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual.Using this model,we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak.The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective,enabling a quantitative assessment of different interventions.Seemingly,this model is also applicable to studying stochastic processes at the “meter scale”,e.g.,human society’s collective dynamics.展开更多
There are various phenomena of malicious information spreading in the real society, which cause many negative impacts on the society. In order to better control the spreading, it is crucial to reveal the influence of ...There are various phenomena of malicious information spreading in the real society, which cause many negative impacts on the society. In order to better control the spreading, it is crucial to reveal the influence of network structure on network spreading. Motifs, as fundamental structures within a network, play a significant role in spreading. Therefore, it is of interest to investigate the influence of the structural characteristics of basic network motifs on spreading dynamics.Considering the edges of the basic network motifs in an undirected network correspond to different tie ranges, two edge removal strategies are proposed, short ties priority removal strategy and long ties priority removal strategy. The tie range represents the second shortest path length between two connected nodes. The study focuses on analyzing how the proposed strategies impact network spreading and network structure, as well as examining the influence of network structure on network spreading. Our findings indicate that the long ties priority removal strategy is most effective in controlling network spreading, especially in terms of spread range and spread velocity. In terms of network structure, the clustering coefficient and the diameter of network also have an effect on the network spreading, and the triangular structure as an important motif structure effectively inhibits the spreading.展开更多
Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy ...Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy for revascularization. Cortical spreading depression (CSD, also called cortical spreading depolarization) is a pathophysiological phenomenon whereby a wave of depolarization is thought to propagate across the cerebral cortex, creating a brief period of relative neuronal inactivity. The relationship between CSD and seizures is unclear, although some literature has made a correlation between seizures and a cortical environment conducive to CSD. Methods: Intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) were monitored continuously during the craniotomy procedure utilizing standard montages. Electrophysiological data from pre-ictal, ictal, and post-ictal periods were recorded. Results: During the procedure, intraoperative EEG captured a generalized seizure followed by a stepwise decrease in somatosensory evoked potential cortical amplitudes, compelling for the phenomenon of CSD. The subsequent partial recovery of neuronal function was also captured electrophysiologically. Discussion: While CSD is considered controversial in some aspects, intraoperative neurophysiological monitoring allowed for the unique analysis of a case demonstrating a CSD-like phenomenon. To our knowledge, this is the first published example of this phenomenon in which intraoperative neurophysiological monitoring captured a seizure, along with a stepwise subsequent reduction in SSEP cortical amplitudes not explained by other variables.展开更多
This paper introduces agricultural catastrophe and its characteristics,and conducts comparative analysis on existing mechanism of spreading agricultural catastrophe risk,indicating that the mechanism of administrative...This paper introduces agricultural catastrophe and its characteristics,and conducts comparative analysis on existing mechanism of spreading agricultural catastrophe risk,indicating that the mechanism of administrative remedy has the greatest efficiency and highest cost;the mechanism of social assistance has the lowest cost,but its efficiency is lowest and there are unstable factors;market mechanism,namely the insurance of agricultural catastrophe,is the rational choice of agricultural department in mechanism of risk spreading.This paper analyzes the status quo of China's insurance of agricultural catastrophe,indicating that the main body of management in China's insurance of agricultural catastrophe is missing.In addition,the market demand is critically scanty,and insurance of agricultural catastrophe lacks external development environment.The gap of China's insurance law of agricultural catastrophe has become the greatest obstacle to the development of insurance of agricultural catastrophe.From legislative purpose,basic principle,nature,main body of legal relations,management range,policy support,supervision and management and so on,the legislation conception of China's insurance of agricultural catastrophe is put forward.展开更多
To understand the forming and tectonic evolution of the South China Sea basin, new data of the structural styles and geochronology were obtained from the Dulong-Song Chay dome, southeastern Yunnan and northern Vietnam...To understand the forming and tectonic evolution of the South China Sea basin, new data of the structural styles and geochronology were obtained from the Dulong-Song Chay dome, southeastern Yunnan and northern Vietnam. The structural styles were acquired through field investigation and geo-chronological dating was carried out using zircon SHRIMP Ⅱ U-P and argon isotopic analyses. The South China Sea basin extension occurred firstly at Late Mesozoic to Early Cenozoic, and then at Late Oligocene to Middle Miocene (32-17 Ma). The second stage of extension formed immediately after the first stage, and both extensions have a consistent forming mechanism. New structural analysis and geo-chronological data do not support the models of "backarc spreading" and "strike-slip faults producing the extension". Then what mechanism resulted in the extension of South China Sea basin? The data indicate that at least two episodes of major extensional tectonics, i.e. , the D1 deformation at 237-228 Ma resulted in the rising and exhumation of the dome, and D2 deformation at 86-78 Ma overprinted and redeformed the dome. Of them, the D2 shows a consistent forming time, extensional direction and tectonic regime among Dulong-Song Chay dome, South China block and the northern margin of the South China Sea basin. Regional geology has proved that the northern margin of the South China Sea basin belongs to the South China block, therefore, we interpreted that the Late Mesozoic to Early Cenozoic extensional tectonics occurred in the northern margin of the South China Sea basin due to the intraplate deformation of the South China block, while the Ailaoshan-Red River sinistral slip strengthened the Cenozoic extension in the South China Sea basin.展开更多
In order to reduce the risks for the spread of disease in cattle movements, we investigated China’s cattle breeding and movement pattern, analyzed risk factors of disease infection caused by long-distance movement, e...In order to reduce the risks for the spread of disease in cattle movements, we investigated China’s cattle breeding and movement pattern, analyzed risk factors of disease infection caused by long-distance movement, explored the relevant risk management measures and conjectured the direction of cattle movement based on the regional distribution of cattle inventory and beef price. We also constructed a market value chain in live cattle movements and qualitatively analyzed the risks for unapparent infection in the process of movement. Meanwhile, we put forward a long-term policy of reducing the risks for unapparent infection and animal health supervision measures.展开更多
A dynamic mechanism, "lower lithospheric delamination and extension of the Cathaysian Diwa-type orogens" , has been put forward to explain the formation of the Cenozoic continental-margin-spreading-belt in S...A dynamic mechanism, "lower lithospheric delamination and extension of the Cathaysian Diwa-type orogens" , has been put forward to explain the formation of the Cenozoic continental-margin-spreading-belt in Southeast China. The processes of formation and develop-ment for the belt are from the stage of the Cathaysian Diwa-type orogens at which compression and thickening of curstobodies prevailed, to the stage of the basin-and-range-type structures at which the late orogenic crustal extension occurred, and then to the stage of the epicontinental Diwa-type rifts at which the lithospheric extension took place.展开更多
Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. ...Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. In order to constrain the emplacement age of these dykes, zircons of two samples from diabases in Nagarzê were dated by using the U-Pb SHRIMP method. Two nearly the same weighted mean ^206pb/^23SU ages were obtained in this paper, which are 134.9±1.8 Ma (MSWD=0.65) and 135.5 ± 2.1 Ma (MSWD=1.40), respectively. They not only represent the crystallization age of the diabase, but also documented an important spreading event of the Neo-Tethys Ocean during the late Jurassic and early Cretaceous. This dating result is of great significance to reconstruct the temporal framework of the late Neo-Tethys Ocean in the Qinghai-Tibet Plateau.展开更多
Esophageal carcinoma(EC) is a highly lethal malignancywith a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influe...Esophageal carcinoma(EC) is a highly lethal malignancywith a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influences the outcome of surgical treatment for EC. However, the lymphatic drainage system of the esophagus, including an abundant lymph-capillary network in the lamina propria and muscularis mucosa, is very complex with cervical, mediastinal and celiac node spreading. The extent of lymphadenectomy for EC has always been controversial because of the very complex pattern of lymph node spreading. In this article, published literature regarding lymphatic spreading was reviewed and the current lymphadenectomy trends for EC are discussed.展开更多
It is a necessary step to estimate the spreading sequence of direct sequence spread spectrum (DSSS) signal for blind despreading and demodulation in non-cooperative communications. Two innovative and effective detec...It is a necessary step to estimate the spreading sequence of direct sequence spread spectrum (DSSS) signal for blind despreading and demodulation in non-cooperative communications. Two innovative and effective detection statistics are proposed to implement the synchronization and spreading sequence estimation procedure. The proposed algorithm also has a low computational complexity with only linear additions and modifications. Theoretical analysis and simulation results show that the algorithm performs quite well in low SNR environment, and is much better than all the existing typical algorithms with a comprehensive consideration both in performance and computational complexity.展开更多
The response of pile foundations near a quay wall under liquefaction-induced lateral spreading remains a complex problem. This study presents the results of a shake-table test on a 2×2 pile group behind a sheet-p...The response of pile foundations near a quay wall under liquefaction-induced lateral spreading remains a complex problem. This study presents the results of a shake-table test on a 2×2 pile group behind a sheet-pile quay wall that was subjected to lateral spreading. The quay wall was employed to trigger liquefaction-induced large lateral ground deformation. The discussions focus on the behavior of the pile and the soil and on the bending moment distributions within the group pile and the restoring force characteristics at the superstructure. Overall, the piles exhibited apparent pinning effects that reduced soil deformation. In addition, the rear-row piles near the quay wall experienced larger bending moments than did the front-row piles, indicating significant pile group effects. The tests showed that lateral spreading could be a primary cause of larger monotonic deformations and bending moments. It can also be concluded that the monotonic bending moments were significantly decreased due to the presence of slow soil flow. The stiffness at the superstructure was reduced because of accumulated excess pore pressure before liquefaction, and it was recovered during lateral spreading. The present study further enhances current understanding of the behavior of low-cap pile foundations under lateral spreading.展开更多
This paper evaluates the seismic vulnerability of different classes of typical bridges in California when subjected to seismic shaking or liquefaction-induced lateral spreading. The detailed structural configurations ...This paper evaluates the seismic vulnerability of different classes of typical bridges in California when subjected to seismic shaking or liquefaction-induced lateral spreading. The detailed structural configurations in terms of superstructure type, connection, continuity at support and foundation type, etc. render different damage resistant capability. Six classes of bridges are established based on their anticipated failure mechanisms under earthquake shaking. The numerical models that are capable of simulating the complex soil-structure interaction effects, nonlinear behavior of columns and connections are developed for each bridge class. The dynamic responses are obtained using nonlinear time history analyses for a suite of 250 earthquake motions with increasing intensity. An equivalent static analysis procedure is also implemented to evaluate the vulnerability of the bridges when subjected to liquefaction-induced lateral spreading. Fragility functions for each bridge class are derived and compared for both seismic shaking (based on nonlinear dynamic analyses) and lateral spreading (based on equivalent static analyses) for different performance states. The study finds that the fragility functions due to either ground shaking or lateral spreading show significant correlation with the structural characterizations, but differences emerge for ground shaking and lateral spreading conditions. Structural properties that will mostly affect the bridges' damage resistant capacity are also identified.展开更多
In this paper, we investigate the regularity of spreading of information and public opinions towards two competing products in complex networks. By building its mathematical model and simulating its evolution process,...In this paper, we investigate the regularity of spreading of information and public opinions towards two competing products in complex networks. By building its mathematical model and simulating its evolution process, we have found the statistical regularity for support rates of two different products at a steady stage. The research shows that strength of the public opinion spreading is proportional to the final support rates of a product.展开更多
A revised empirical model has been developed for predicting liquefaction-induced lateral spreading displacement (LD) as a function of both response spectral acceleration derived from strong-motion attenuation models...A revised empirical model has been developed for predicting liquefaction-induced lateral spreading displacement (LD) as a function of both response spectral acceleration derived from strong-motion attenuation models and geotechnical parameters from Youd's LD data set (Youd website). This revised model is different from the model of Zhang and Zhao, which overcame some drawbacks of earlier models for predicting lateral spreading and was primarily used in Japan and the western U.S. The revised model can potentially be applied anywhere if ground shaking (in terms of 5% damped acceleration or displacement response spectra) can be estimated using local strong-motion attenuation relationships. The revised model is examined using data from Japan and the western U.S. and applied to Turkey and New Zealand, where the ground shaking is estimated using appropriate strong-motion attenuation relationships for each region. The accuracy of the revised model is evaluated by comparing its predicted lateral displacements with those measured in actual earthquakes. The results show that the revised model can account for the effects of local seismicity on lateral spreading displacements and is comparable with existing prediction models.展开更多
Lateral spread of frozen ground crust over liquefied soil has caused extensive bridge foundation damage in the past winter earthquakes.A shake table experiment was conducted to investigate the performance of a model p...Lateral spread of frozen ground crust over liquefied soil has caused extensive bridge foundation damage in the past winter earthquakes.A shake table experiment was conducted to investigate the performance of a model pile in this scenario and revealed unique pile failure mechanisms.The modelling results provided valuable data for validating numerical models.This paper presents analyses and results of this experiment using two numerical modeling approaches: solid-fluid coupled finite element(FE) modeling and the beam-on-nonlinear-Winkler-foundation(BNWF) method.A FE model was constructed based on the experiment configuration and subjected to earthquake loading.Soil and pile response results were presented and compared with experimental results to validate this model.The BNWF method was used to predict the pile response and failure mechanism.A p-y curve was presented for modelling the frozen ground crust with the free-field displacement from the experiment as loading.Pile responses were presented and compared with those of the experiment and FE model.It was concluded that the coupled FE model was effective in predicting formation of three plastic hinges at ground surface,ground crust-liquefiable soil interface and within the medium dense sand layer,while the BNWF method was only able to predict the latter two.展开更多
文摘The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(GEP).Based on statistical reasoning,individual models were developed for two topographies:free-face and gently sloping ground.Along with a comparison with conventional approaches for predicting the Dh,four additional regression-based soft computing models,i.e.Gaussian process regression(GPR),relevance vector machine(RVM),sequential minimal optimization regression(SMOR),and M5-tree,were developed and compared with the GEP model.The results indicate that the GEP models predict Dh with less bias,as evidenced by the root mean square error(RMSE)and mean absolute error(MAE)for training(i.e.1.092 and 0.815;and 0.643 and 0.526)and for testing(i.e.0.89 and 0.705;and 0.773 and 0.573)in free-face and gently sloping ground topographies,respectively.The overall performance for the free-face topology was ranked as follows:GEP>RVM>M5-tree>GPR>SMOR,with a total score of 40,32,24,15,and 10,respectively.For the gently sloping condition,the performance was ranked as follows:GEP>RVM>GPR>M5-tree>SMOR with a total score of 40,32,21,19,and 8,respectively.Finally,the results of the sensitivity analysis showed that for both free-face and gently sloping ground,the liquefiable layer thickness(T_(15))was the major parameter with percentage deterioration(%D)value of 99.15 and 90.72,respectively.
文摘The rock series, rock types and Sr-Nd isotopic dating of the Cenozoicvolcanic rocks in the South China Sea are similar to those in its vicinity. On the basis of thespreading age of the South China Sea, the Cenozoic volcanic rocks are divided into three stages: thepre-spreading stage, the spreading stage and the post-spreading stage. The deep processcharacteristics of the asthenosphere and lithosphere may be inferred from the study on primarybasaltic magma. The top layers of the asthenosphere both in the spreading stage and in thepre-spreading stage are closer to the earth surface than that in the post-spreading stage. From thepre-spreading stage to the spreading stage, the top layer of the asthenosphere decreased in depth,while the amount of interstitial partial melts increased. The evolution of the primary basalticmagma shows a progressive evolution sequence of the rifting volcanism and a faster lithosphericspreading velocity. From the spreading stage to the post-spreading stage, the top layer of theasthenosphere gradually increased in depth, but the amount of interstitial partial melts decreased.The evolution of primary basaltic magma shows a retrogressive evolution sequence of the riftingvolcanism and a gradual decrease in the lithospheric spreading velocity. The depth recognized by thestudy on the Cenozoic volcanism demonstrates the deep environment for the formation and evolutionof the South China Sea.
基金This study was supported by the National Major Fundamental Research Development Project of China under contract No. G2000046704.
文摘With processing and interpretation of 25 000 km full-coverage multibeam swath data fromthe eastern South China Sea, it is found that NE-trending and NW-trending linear morphological features such as scarps, horsts and grabens, govern the central part (14°-17° N) of eastern subbasin. Compared with reflection seismic profiles, these NE-trending linear morpho-structures are considered to be the representation of basement structures on seabed and can be divided into three linear structural zones. The trend of the central zone is NE45°-50° occurring around extinct spreading center, the trend of the second zone is NE70° - 78° on both sides of the central one and the trend of the third zone is about NE60° just on the north of the second one. These three NE-trending linear zones are formed in late-stage NW - SE-trending seafloor spreading of the eastern subbasin along NW-trending linear faults, and respectively correspond to three spreading episodes: 17.0- 19.0 Ma (5d-5e), 19.0 - 21.0 Ma (5e-6a) and 21.0 - 24.2 Ma (6a-6c) based on the contrast of morpho-structures to magnetic lineation anomalies.
基金supported by the National Natural Science Foundation of China(Grant No.22273034)the Frontiers Science Center for Critical Earth Material Cycling of Nanjing University。
文摘The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features,their treatment usually lacks spatiotemporal variation.Here,we propose a stochastic individual dynamical(SID)model to mimic the random and heterogeneous nature of epidemic propagation.The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual.Using this model,we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak.The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective,enabling a quantitative assessment of different interventions.Seemingly,this model is also applicable to studying stochastic processes at the “meter scale”,e.g.,human society’s collective dynamics.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62373197 and 62203229)the Postgraduate Research & Practice Innovation Program of Jiangsu Province, China (Grant No. KYCX24_1211)。
文摘There are various phenomena of malicious information spreading in the real society, which cause many negative impacts on the society. In order to better control the spreading, it is crucial to reveal the influence of network structure on network spreading. Motifs, as fundamental structures within a network, play a significant role in spreading. Therefore, it is of interest to investigate the influence of the structural characteristics of basic network motifs on spreading dynamics.Considering the edges of the basic network motifs in an undirected network correspond to different tie ranges, two edge removal strategies are proposed, short ties priority removal strategy and long ties priority removal strategy. The tie range represents the second shortest path length between two connected nodes. The study focuses on analyzing how the proposed strategies impact network spreading and network structure, as well as examining the influence of network structure on network spreading. Our findings indicate that the long ties priority removal strategy is most effective in controlling network spreading, especially in terms of spread range and spread velocity. In terms of network structure, the clustering coefficient and the diameter of network also have an effect on the network spreading, and the triangular structure as an important motif structure effectively inhibits the spreading.
文摘Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy for revascularization. Cortical spreading depression (CSD, also called cortical spreading depolarization) is a pathophysiological phenomenon whereby a wave of depolarization is thought to propagate across the cerebral cortex, creating a brief period of relative neuronal inactivity. The relationship between CSD and seizures is unclear, although some literature has made a correlation between seizures and a cortical environment conducive to CSD. Methods: Intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) were monitored continuously during the craniotomy procedure utilizing standard montages. Electrophysiological data from pre-ictal, ictal, and post-ictal periods were recorded. Results: During the procedure, intraoperative EEG captured a generalized seizure followed by a stepwise decrease in somatosensory evoked potential cortical amplitudes, compelling for the phenomenon of CSD. The subsequent partial recovery of neuronal function was also captured electrophysiologically. Discussion: While CSD is considered controversial in some aspects, intraoperative neurophysiological monitoring allowed for the unique analysis of a case demonstrating a CSD-like phenomenon. To our knowledge, this is the first published example of this phenomenon in which intraoperative neurophysiological monitoring captured a seizure, along with a stepwise subsequent reduction in SSEP cortical amplitudes not explained by other variables.
文摘This paper introduces agricultural catastrophe and its characteristics,and conducts comparative analysis on existing mechanism of spreading agricultural catastrophe risk,indicating that the mechanism of administrative remedy has the greatest efficiency and highest cost;the mechanism of social assistance has the lowest cost,but its efficiency is lowest and there are unstable factors;market mechanism,namely the insurance of agricultural catastrophe,is the rational choice of agricultural department in mechanism of risk spreading.This paper analyzes the status quo of China's insurance of agricultural catastrophe,indicating that the main body of management in China's insurance of agricultural catastrophe is missing.In addition,the market demand is critically scanty,and insurance of agricultural catastrophe lacks external development environment.The gap of China's insurance law of agricultural catastrophe has become the greatest obstacle to the development of insurance of agricultural catastrophe.From legislative purpose,basic principle,nature,main body of legal relations,management range,policy support,supervision and management and so on,the legislation conception of China's insurance of agricultural catastrophe is put forward.
文摘To understand the forming and tectonic evolution of the South China Sea basin, new data of the structural styles and geochronology were obtained from the Dulong-Song Chay dome, southeastern Yunnan and northern Vietnam. The structural styles were acquired through field investigation and geo-chronological dating was carried out using zircon SHRIMP Ⅱ U-P and argon isotopic analyses. The South China Sea basin extension occurred firstly at Late Mesozoic to Early Cenozoic, and then at Late Oligocene to Middle Miocene (32-17 Ma). The second stage of extension formed immediately after the first stage, and both extensions have a consistent forming mechanism. New structural analysis and geo-chronological data do not support the models of "backarc spreading" and "strike-slip faults producing the extension". Then what mechanism resulted in the extension of South China Sea basin? The data indicate that at least two episodes of major extensional tectonics, i.e. , the D1 deformation at 237-228 Ma resulted in the rising and exhumation of the dome, and D2 deformation at 86-78 Ma overprinted and redeformed the dome. Of them, the D2 shows a consistent forming time, extensional direction and tectonic regime among Dulong-Song Chay dome, South China block and the northern margin of the South China Sea basin. Regional geology has proved that the northern margin of the South China Sea basin belongs to the South China block, therefore, we interpreted that the Late Mesozoic to Early Cenozoic extensional tectonics occurred in the northern margin of the South China Sea basin due to the intraplate deformation of the South China block, while the Ailaoshan-Red River sinistral slip strengthened the Cenozoic extension in the South China Sea basin.
文摘In order to reduce the risks for the spread of disease in cattle movements, we investigated China’s cattle breeding and movement pattern, analyzed risk factors of disease infection caused by long-distance movement, explored the relevant risk management measures and conjectured the direction of cattle movement based on the regional distribution of cattle inventory and beef price. We also constructed a market value chain in live cattle movements and qualitatively analyzed the risks for unapparent infection in the process of movement. Meanwhile, we put forward a long-term policy of reducing the risks for unapparent infection and animal health supervision measures.
文摘A dynamic mechanism, "lower lithospheric delamination and extension of the Cathaysian Diwa-type orogens" , has been put forward to explain the formation of the Cenozoic continental-margin-spreading-belt in Southeast China. The processes of formation and develop-ment for the belt are from the stage of the Cathaysian Diwa-type orogens at which compression and thickening of curstobodies prevailed, to the stage of the basin-and-range-type structures at which the late orogenic crustal extension occurred, and then to the stage of the epicontinental Diwa-type rifts at which the lithospheric extension took place.
文摘Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. In order to constrain the emplacement age of these dykes, zircons of two samples from diabases in Nagarzê were dated by using the U-Pb SHRIMP method. Two nearly the same weighted mean ^206pb/^23SU ages were obtained in this paper, which are 134.9±1.8 Ma (MSWD=0.65) and 135.5 ± 2.1 Ma (MSWD=1.40), respectively. They not only represent the crystallization age of the diabase, but also documented an important spreading event of the Neo-Tethys Ocean during the late Jurassic and early Cretaceous. This dating result is of great significance to reconstruct the temporal framework of the late Neo-Tethys Ocean in the Qinghai-Tibet Plateau.
文摘Esophageal carcinoma(EC) is a highly lethal malignancywith a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influences the outcome of surgical treatment for EC. However, the lymphatic drainage system of the esophagus, including an abundant lymph-capillary network in the lamina propria and muscularis mucosa, is very complex with cervical, mediastinal and celiac node spreading. The extent of lymphadenectomy for EC has always been controversial because of the very complex pattern of lymph node spreading. In this article, published literature regarding lymphatic spreading was reviewed and the current lymphadenectomy trends for EC are discussed.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education (20060003032)
文摘It is a necessary step to estimate the spreading sequence of direct sequence spread spectrum (DSSS) signal for blind despreading and demodulation in non-cooperative communications. Two innovative and effective detection statistics are proposed to implement the synchronization and spreading sequence estimation procedure. The proposed algorithm also has a low computational complexity with only linear additions and modifications. Theoretical analysis and simulation results show that the algorithm performs quite well in low SNR environment, and is much better than all the existing typical algorithms with a comprehensive consideration both in performance and computational complexity.
基金National Natural Science Foundation of China under Grant Nos.51378161 and 51108134
文摘The response of pile foundations near a quay wall under liquefaction-induced lateral spreading remains a complex problem. This study presents the results of a shake-table test on a 2×2 pile group behind a sheet-pile quay wall that was subjected to lateral spreading. The quay wall was employed to trigger liquefaction-induced large lateral ground deformation. The discussions focus on the behavior of the pile and the soil and on the bending moment distributions within the group pile and the restoring force characteristics at the superstructure. Overall, the piles exhibited apparent pinning effects that reduced soil deformation. In addition, the rear-row piles near the quay wall experienced larger bending moments than did the front-row piles, indicating significant pile group effects. The tests showed that lateral spreading could be a primary cause of larger monotonic deformations and bending moments. It can also be concluded that the monotonic bending moments were significantly decreased due to the presence of slow soil flow. The stiffness at the superstructure was reduced because of accumulated excess pore pressure before liquefaction, and it was recovered during lateral spreading. The present study further enhances current understanding of the behavior of low-cap pile foundations under lateral spreading.
基金Supported by:Pacific Earthquake Engineering Research Center Lifelines Program Under Project Task No.9C
文摘This paper evaluates the seismic vulnerability of different classes of typical bridges in California when subjected to seismic shaking or liquefaction-induced lateral spreading. The detailed structural configurations in terms of superstructure type, connection, continuity at support and foundation type, etc. render different damage resistant capability. Six classes of bridges are established based on their anticipated failure mechanisms under earthquake shaking. The numerical models that are capable of simulating the complex soil-structure interaction effects, nonlinear behavior of columns and connections are developed for each bridge class. The dynamic responses are obtained using nonlinear time history analyses for a suite of 250 earthquake motions with increasing intensity. An equivalent static analysis procedure is also implemented to evaluate the vulnerability of the bridges when subjected to liquefaction-induced lateral spreading. Fragility functions for each bridge class are derived and compared for both seismic shaking (based on nonlinear dynamic analyses) and lateral spreading (based on equivalent static analyses) for different performance states. The study finds that the fragility functions due to either ground shaking or lateral spreading show significant correlation with the structural characterizations, but differences emerge for ground shaking and lateral spreading conditions. Structural properties that will mostly affect the bridges' damage resistant capacity are also identified.
文摘In this paper, we investigate the regularity of spreading of information and public opinions towards two competing products in complex networks. By building its mathematical model and simulating its evolution process, we have found the statistical regularity for support rates of two different products at a steady stage. The research shows that strength of the public opinion spreading is proportional to the final support rates of a product.
基金National Natural Science Foundation SF of China Under Grant No.41030742NBRP of China Under Grant No. 2011CB013605the Foundation for Research and Science and Technology of New Zealand Under Grant No.C05X0402
文摘A revised empirical model has been developed for predicting liquefaction-induced lateral spreading displacement (LD) as a function of both response spectral acceleration derived from strong-motion attenuation models and geotechnical parameters from Youd's LD data set (Youd website). This revised model is different from the model of Zhang and Zhao, which overcame some drawbacks of earlier models for predicting lateral spreading and was primarily used in Japan and the western U.S. The revised model can potentially be applied anywhere if ground shaking (in terms of 5% damped acceleration or displacement response spectra) can be estimated using local strong-motion attenuation relationships. The revised model is examined using data from Japan and the western U.S. and applied to Turkey and New Zealand, where the ground shaking is estimated using appropriate strong-motion attenuation relationships for each region. The accuracy of the revised model is evaluated by comparing its predicted lateral displacements with those measured in actual earthquakes. The results show that the revised model can account for the effects of local seismicity on lateral spreading displacements and is comparable with existing prediction models.
基金US Department of Transportation through Alaska University Transportation Centerthe State of Alaska Department of Transportation and Public Facilities(AK DOT&PF)under Project AUTC#410015
文摘Lateral spread of frozen ground crust over liquefied soil has caused extensive bridge foundation damage in the past winter earthquakes.A shake table experiment was conducted to investigate the performance of a model pile in this scenario and revealed unique pile failure mechanisms.The modelling results provided valuable data for validating numerical models.This paper presents analyses and results of this experiment using two numerical modeling approaches: solid-fluid coupled finite element(FE) modeling and the beam-on-nonlinear-Winkler-foundation(BNWF) method.A FE model was constructed based on the experiment configuration and subjected to earthquake loading.Soil and pile response results were presented and compared with experimental results to validate this model.The BNWF method was used to predict the pile response and failure mechanism.A p-y curve was presented for modelling the frozen ground crust with the free-field displacement from the experiment as loading.Pile responses were presented and compared with those of the experiment and FE model.It was concluded that the coupled FE model was effective in predicting formation of three plastic hinges at ground surface,ground crust-liquefiable soil interface and within the medium dense sand layer,while the BNWF method was only able to predict the latter two.