In order to improve the performance of the probability hypothesis density(PHD) algorithm based particle filter(PF) in terms of number estimation and states extraction of multiple targets, a new probability hypothesis ...In order to improve the performance of the probability hypothesis density(PHD) algorithm based particle filter(PF) in terms of number estimation and states extraction of multiple targets, a new probability hypothesis density filter algorithm based on marginalized particle and kernel density estimation is proposed, which utilizes the idea of marginalized particle filter to enhance the estimating performance of the PHD. The state variables are decomposed into linear and non-linear parts. The particle filter is adopted to predict and estimate the nonlinear states of multi-target after dimensionality reduction, while the Kalman filter is applied to estimate the linear parts under linear Gaussian condition. Embedding the information of the linear states into the estimated nonlinear states helps to reduce the estimating variance and improve the accuracy of target number estimation. The meanshift kernel density estimation, being of the inherent nature of searching peak value via an adaptive gradient ascent iteration, is introduced to cluster particles and extract target states, which is independent of the target number and can converge to the local peak position of the PHD distribution while avoiding the errors due to the inaccuracy in modeling and parameters estimation. Experiments show that the proposed algorithm can obtain higher tracking accuracy when using fewer sampling particles and is of lower computational complexity compared with the PF-PHD.展开更多
A marginalized particle filtering （MPF） approach is proposed for target tracking under the background of passive measurement. Essentially, the MPF is a combination of particle filtering technique and Kalman filter. ...A marginalized particle filtering （MPF） approach is proposed for target tracking under the background of passive measurement. Essentially, the MPF is a combination of particle filtering technique and Kalman filter. By making full use of marginalization, the distributions of the tractable linear part of the total state variables are updated analytically using Kalman filter, and only the lower-dimensional nonlinear state variable needs to be dealt with using particle filter. Simulation studies are performed on an illustrative example, and the results show that the MPF method leads to a significant reduction of the tracking errors when compared with the direct particle implementation. Real data test results also validate the effectiveness of the presented method.展开更多
Aiming at improving the estimation accuracy and real-time of nonlinear system with linear Gaussian sub-structure,a novel marginalized cubature Kalman filter is proposed in Bayesian estimation framework. Firstly,the ma...Aiming at improving the estimation accuracy and real-time of nonlinear system with linear Gaussian sub-structure,a novel marginalized cubature Kalman filter is proposed in Bayesian estimation framework. Firstly,the marginalized technique is adopted to model the target system dynamics with nonlinear state and linear state separately,and the two parts are estimated by cubature Kalman filter and standard Kalman filter respectively. Therefore,the linear part avoids the generation and propagation process of cubature points. Accordingly,the computational complexity is reduced.Meanwhile,the accuracy of state estimation is improved by taking the difference of nonlinear state estimation as the measurement of linear state. Furthermore,the computational complexity of marginalized cubature Kalman filter is discussed by calculating the number of floating-point operation. Finally,simulation experiments and analysis show that the proposed algorithm can improve the performance of filtering precision and real-time effectively in target tracking system.展开更多
Counting data without zero category often occurs in many fields,such as social studies,clinical trials and economic phenomenon analyses.Researchers usually show interest in describing the characteristics of the observ...Counting data without zero category often occurs in many fields,such as social studies,clinical trials and economic phenomenon analyses.Researchers usually show interest in describing the characteristics of the observed counts and the Poisson distribution is often preferred to model the counted data.Nevertheless,making marginal inference on the population mean is a challenging job when missing zero class occurs and the Poisson mean is considered as an alternative.In this paper,based on a so-called marginalized zero-truncated Poisson(ZTP)regression model,a novel SR-based EMFS algorithm is proposed to facilitate parameter estimation.To improve the prediction accuracy,this paper proposes a zero-truncated Poisson model averaging prediction that selects the optimal weight combination by minimizing a Kullback-Leibler(KL)divergence criterion.It is shown that the weight criterion is approximately unbiased about the expected KL loss.We further prove that the proposed prediction is asymptotically optimal in the sense that the KL-type loss and prediction risk are asymptotically identical to those of the infeasible best possible averaged prediction.Simulations and two empirical data applications are conducted to illustrate the proposed method.展开更多
This study is in order to implement the mandate of UNESCO(2003)on the documentation of architectural heritage of the modern period of the 19th-20th century,where in reality several typologies of architectural heritage...This study is in order to implement the mandate of UNESCO(2003)on the documentation of architectural heritage of the modern period of the 19th-20th century,where in reality several typologies of architectural heritage are currently in a marginalized condition.As part of the history of modern architecture in Indonesia,transformator huisje(Dutch)or“gardu listrik”(Indonesian)which still exist today,are not widely known as buildings that have important values in the past.This study aims to reveal whether transformator huisje architecture is classifled as Modern Heritage,by tracing its historical background.Architectural analysis of 61 transformator huisje was conducted to build a“genesis”—a scheme of origin—of transformator huisje which can explain how this type of architecture was formed in accordance with the values or principles of modern architecture.The study flndings show that all design features of transformator huisje as buildings for machines are strong representations of Modern Architectural Heritage in Asia,especially the Dutch East Indies(Indonesia).In conclusion,with the flnding that transformator huisje is categorized as Modern Architectural Heritage,a strategy is needed to maintain this type of architecture as evidence of modern civilization in Indonesia.展开更多
Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust...Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences.展开更多
This article deals with the problem of maneuvering target tracking which results in a mixed linear/non-linear model estimation problem. For maneuvering tracking system, extended Kalman filter （EKF） or particle filt...This article deals with the problem of maneuvering target tracking which results in a mixed linear/non-linear model estimation problem. For maneuvering tracking system, extended Kalman filter （EKF） or particle filter （PF） is traditionally used to estimate the states. In this article, marginalized particle filter （MPF） is presented for application in a mixed linear/non-linear model estimation problem. MPF is a combination of Kalman filter （KF） and PF. So it holds both advantage of them and can be used for mixed linear/non-linear substructure, where the conditionally linear states are estimated using KF and the nonlinear states are estimated using PF. Simulation results show that MPF guarantees the estimation accuracy and alleviates the potential computational burden problem compared with PF and EKF in maneuvering target tracking application.展开更多
The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphy...The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphyry(PG).To investigate the mineralization significance of three porphyries,Microthermometry,Laser micro-Raman Spectra,and H-O-He-Ar isotope analyses of fluid inclusions were conducted.Intermediate density with high temperatures(>550℃)and moderate-low salinities(~10 wt.%)characterizes CG-related initial exsolved fluids.Vapor-rich and brine phases separated from the initial fluid following a continuous decrease in pressure and temperature,inducing molybdenite precipitation.FG-related initial fluids are characterized by high temperatures(>550℃)and salinities(>65 wt.%).The mixing of low-salinity fluids led to a rapid decrease in the salinity of FG-related fluid,promoting the deposit of the Mo element.The lead-zinc mineralization is closely related to the FG-related fluid,and the addition of meteoric fluid induced the formation of galena and sphalerite.The ore-forming fluid related to the PG is CO_(2)-rich and accompanied by the addition of mantle-derived He-Ar.The presence of CO_(2) did not contribute to the solubility of Mo,resulting in the absence of a considerable amount of molybdenite.展开更多
Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remain...Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remains insufficiently explored.This study investigates the dynamic response of a deposit slope containing a weak interlayer through large-scale shaking table tests.The propagation process of the sliding surface was identified using the Hilbert-Huang transform and marginal spectrum analysis.Under seismic excitation,sliding occurs along the interface between the overburden and the weak interlayer,leading to sudden landslide events.Differential vibrations at the overburden-weak interlayer-bedrock interfaces are identified as a primary mechanism driving landslide initiation.As input acceleration increases,these interfacial vibration contrasts intensify,and the acceleration amplification effect within the overburden becomes markedly pronounced.Following landslide occurrence,the vibration differences across interfaces decrease sharply.In the time-frequency domain,seismic waves transmitted through the weak interlayer exhibit amplified low-frequency components.Marginal spectrum analysis of seismic energy evolution within the slope reveals that energy attenuation in the 19-22 Hz frequency band correlates with landslide occurrence,while attenuation in the 9-11 Hz band serves as an indicator for sliding surface propagation and coalescence.For seismic design of deposit slopes with weak interlayers,particular attention should be given to the increased seismic inertial forces in the overburden layer and the detrimental effects of low-frequency wave components on sliding surface development.展开更多
Predicting Antarctic sea ice is of substantial academic and practical significance.However,current prediction models,including deep learning(DL)-based models,show notable bias in the marginal ice zone.In this study,we...Predicting Antarctic sea ice is of substantial academic and practical significance.However,current prediction models,including deep learning(DL)-based models,show notable bias in the marginal ice zone.In this study,we developed a pure data-driven DL model for predicting the Antarctic austral summer monthly-to-seasonal sea ice concentration(SIC)by incorporating a novel hybrid sea ice edge constraint loss function(HybridLoss).The model is referred to as ASICNet.Independent testing based on the last five years(2019–23)demonstrates that ASICNet with HybridLoss achieves significantly higher skill metrics than without,with a reduced mean absolute error of 0.021 from 0.022,a reduced integrated ice edge error of 1.714×10^(6)from 1.794×10^(6)km^(2),but an increased pattern correlation coefficient of 0.40 from 0.38,although both ASICNet versions outperform dynamical and statistical models.Furthermore,enhanced heat maps were developed to interpret the predictability sources of sea ice within DL-based models,and the results suggest that the predictability of Antarctic sea ice is attributable to factors like the Antarctic Dipole(ADP),Amundsen Sea Low(ASL),and Southern Ocean sea surface temperature(SST),as revealed in previous studies.Thus,ASICNet is an efficient tool for austral summer Antarctic SIC prediction.展开更多
The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors...The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors,an asymptotic test is proposed under the normality assumption of the predictors as well as an asymmetry assumption about the unknown regression mean function.When these assumptions are violated,the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances.展开更多
Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,th...Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP.展开更多
Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geol...Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geological,and seismic data,and the intrinsic relationships of hydrocarbon distribution in the passive continental margin basins and the differential hydrocarbon accumulation patterns were analyzed.Results show that basins on both sides of the South Atlantic experienced two major extensional phases—rift and depression—and four evolutionary stages:the Early Cretaceous Berriasian-Barremian intracontinental rift stage,the Early Cretaceous Aptian-Albian intercontinental rift to initial drift transition stage,the Late Cretaceous-Paleogene drift-related marine transgressive depression stage,and the Neogene-Quaternary drift-related marine regressive depression stage.According to basin architecture and superposition style,the passive-margin basins are classified into two principal types:rift-continental marginal depression composite and continental marginal depression-dominated.The basins in the study area were further divided into six types based on the development degree of salt tectonics and the type of dominant sand bodies,i.e.salt-free rift-continental marginal gravity-flow composite type,salt-free rift-continental marginal delta composite type,salt-bearing rift-continental marginal gravity flow composite type,delta-dominated salt-bearing rift-continental marginal delta composite type,gravity-flow-dominated continental marginal depression type,and delta-dominated continental marginal depression type.The salt-free rift-continental marginal gravity flow and delta composite basins are mainly distributed in the southern segment.The salt-bearing rift-continental marginal gravity flow and delta composite basins are mainly distributed in the central segment.The gravity-flow-dominated continental marginal depression basins are mainy distributed in the northern segment.The delta-dominated passive-margin depression basins are distributed in three segments from north to south.In different types of basins,distinctive depositional systems and source-reservoir-caprock assemblages were formed in each upper/lower structure layer.The superimposition and evolution of multi-phase prototype basins result in the orderly hydrocarbon accumulation vertically and laterally,which are“segmented along-strike,zoned across-strike,and layered vertically”.展开更多
Vaccination is the preferred strategy for preventing infections such as influenza in elderly individuals;however,its efficacy is often suboptimal due in part to age-related declines in immune function.In this study,we...Vaccination is the preferred strategy for preventing infections such as influenza in elderly individuals;however,its efficacy is often suboptimal due in part to age-related declines in immune function.In this study,we discovered that the infusion of mesenchymal stromal cells(MSCs)restored defects in the splenic stromal cell network and lymphocyte architecture in aged mice while also increasing specific antibody levels following vaccine immunization.This significantly protected aging mice from influenza infection.Mechanistically,the delivered MSCs localized in the splenic marginal zones,where they positioned themselves near marginal reticular cells(MRCs)and stimulated MRC proliferation,partially through the action of vascular endothelial growth factor A(VEGFA).This MSC‒MRC interaction orchestrated the reconstruction of the stromal network,thereby restoring lymphocyte homeostasis and germinal center reactions.Importantly,the MSC-mediated enhancement of the vaccine response was further validated in aged cynomolgus monkeys.Collectively,our findings provide new insights into the application of MSCs in addressing age-related immune decline and highlight splenic MRCs as critical therapeutic targets.展开更多
Eugenics was a discipline founded by the British scholar Galton in 1883 to improve the genetic quality of human beings.When eugenics was introduced to the United States in the early 20th century,it quickly developed i...Eugenics was a discipline founded by the British scholar Galton in 1883 to improve the genetic quality of human beings.When eugenics was introduced to the United States in the early 20th century,it quickly developed into an influential eugenics movement that pointed in new directions to solve the social problems of the United States at that time.In American eugenics movement,eugenicists used family studies to construct the marginalized groups such as the mentally retarded,the poor,and criminals into"hereditary defectives"that would lead to the degradation of the American race.At the same time,they used intelligence tests to demonstrate the"Superiority of the Nordic Race"and to belittle other races,thereby highlighting the dangers of racial mixing.These eugenics discourses provided a plausible justification for segregation,sterilization,and marriage restrictions against marginalized groups in the United States and a"scientific"cloak for restrictive immigration policies,serving as an essential tool for exclusionists to gain support from policymakers and the public.展开更多
基金Project(61101185) supported by the National Natural Science Foundation of ChinaProject(2011AA1221) supported by the National High Technology Research and Development Program of China
文摘In order to improve the performance of the probability hypothesis density(PHD) algorithm based particle filter(PF) in terms of number estimation and states extraction of multiple targets, a new probability hypothesis density filter algorithm based on marginalized particle and kernel density estimation is proposed, which utilizes the idea of marginalized particle filter to enhance the estimating performance of the PHD. The state variables are decomposed into linear and non-linear parts. The particle filter is adopted to predict and estimate the nonlinear states of multi-target after dimensionality reduction, while the Kalman filter is applied to estimate the linear parts under linear Gaussian condition. Embedding the information of the linear states into the estimated nonlinear states helps to reduce the estimating variance and improve the accuracy of target number estimation. The meanshift kernel density estimation, being of the inherent nature of searching peak value via an adaptive gradient ascent iteration, is introduced to cluster particles and extract target states, which is independent of the target number and can converge to the local peak position of the PHD distribution while avoiding the errors due to the inaccuracy in modeling and parameters estimation. Experiments show that the proposed algorithm can obtain higher tracking accuracy when using fewer sampling particles and is of lower computational complexity compared with the PF-PHD.
文摘A marginalized particle filtering （MPF） approach is proposed for target tracking under the background of passive measurement. Essentially, the MPF is a combination of particle filtering technique and Kalman filter. By making full use of marginalization, the distributions of the tractable linear part of the total state variables are updated analytically using Kalman filter, and only the lower-dimensional nonlinear state variable needs to be dealt with using particle filter. Simulation studies are performed on an illustrative example, and the results show that the MPF method leads to a significant reduction of the tracking errors when compared with the direct particle implementation. Real data test results also validate the effectiveness of the presented method.
基金Supported by the National Natural Science Foundation of China(No.61771006)the Open Foundation of Key Laboratory of Spectral Imaging Technology of the Chinese Academy of Sciences(No.LSIT201711D)+1 种基金the Outstanding Young Cultivation Foundation of Henan University(No.0000A40366)the Excellent Chinese and Foreign Youth Exchange Programme of China Science and Technology Association(2017CASTQNJL046)
文摘Aiming at improving the estimation accuracy and real-time of nonlinear system with linear Gaussian sub-structure,a novel marginalized cubature Kalman filter is proposed in Bayesian estimation framework. Firstly,the marginalized technique is adopted to model the target system dynamics with nonlinear state and linear state separately,and the two parts are estimated by cubature Kalman filter and standard Kalman filter respectively. Therefore,the linear part avoids the generation and propagation process of cubature points. Accordingly,the computational complexity is reduced.Meanwhile,the accuracy of state estimation is improved by taking the difference of nonlinear state estimation as the measurement of linear state. Furthermore,the computational complexity of marginalized cubature Kalman filter is discussed by calculating the number of floating-point operation. Finally,simulation experiments and analysis show that the proposed algorithm can improve the performance of filtering precision and real-time effectively in target tracking system.
基金the Editor-in-chief,an AE and two referees for their helpful comments and suggestions,which result in a significant improvement of the manuscriptthe National Natural Science Foundation of China(Grant No.12171483)+3 种基金the Fundamental Research Funds for the Central Universities(2722022BY020)National Natural Science Foundation of China(Grant Nos.71925007,72091212,12288201)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-008)a joint grant from Academy for Multidisciplinary Studies,Capital Normal University.
文摘Counting data without zero category often occurs in many fields,such as social studies,clinical trials and economic phenomenon analyses.Researchers usually show interest in describing the characteristics of the observed counts and the Poisson distribution is often preferred to model the counted data.Nevertheless,making marginal inference on the population mean is a challenging job when missing zero class occurs and the Poisson mean is considered as an alternative.In this paper,based on a so-called marginalized zero-truncated Poisson(ZTP)regression model,a novel SR-based EMFS algorithm is proposed to facilitate parameter estimation.To improve the prediction accuracy,this paper proposes a zero-truncated Poisson model averaging prediction that selects the optimal weight combination by minimizing a Kullback-Leibler(KL)divergence criterion.It is shown that the weight criterion is approximately unbiased about the expected KL loss.We further prove that the proposed prediction is asymptotically optimal in the sense that the KL-type loss and prediction risk are asymptotically identical to those of the infeasible best possible averaged prediction.Simulations and two empirical data applications are conducted to illustrate the proposed method.
文摘This study is in order to implement the mandate of UNESCO(2003)on the documentation of architectural heritage of the modern period of the 19th-20th century,where in reality several typologies of architectural heritage are currently in a marginalized condition.As part of the history of modern architecture in Indonesia,transformator huisje(Dutch)or“gardu listrik”(Indonesian)which still exist today,are not widely known as buildings that have important values in the past.This study aims to reveal whether transformator huisje architecture is classifled as Modern Heritage,by tracing its historical background.Architectural analysis of 61 transformator huisje was conducted to build a“genesis”—a scheme of origin—of transformator huisje which can explain how this type of architecture was formed in accordance with the values or principles of modern architecture.The study flndings show that all design features of transformator huisje as buildings for machines are strong representations of Modern Architectural Heritage in Asia,especially the Dutch East Indies(Indonesia).In conclusion,with the flnding that transformator huisje is categorized as Modern Architectural Heritage,a strategy is needed to maintain this type of architecture as evidence of modern civilization in Indonesia.
文摘Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences.
基金supported by the Science Project of Chongqing Educational Committee (KJ080520)the Natural Science Foundation of Chongqing CSTC (CSTC,2008BB2412)
文摘This article deals with the problem of maneuvering target tracking which results in a mixed linear/non-linear model estimation problem. For maneuvering tracking system, extended Kalman filter （EKF） or particle filter （PF） is traditionally used to estimate the states. In this article, marginalized particle filter （MPF） is presented for application in a mixed linear/non-linear model estimation problem. MPF is a combination of Kalman filter （KF） and PF. So it holds both advantage of them and can be used for mixed linear/non-linear substructure, where the conditionally linear states are estimated using KF and the nonlinear states are estimated using PF. Simulation results show that MPF guarantees the estimation accuracy and alleviates the potential computational burden problem compared with PF and EKF in maneuvering target tracking application.
基金financially supported by the National Natural Science Foundation of China(No.42102084)the Special Research Fund of Natural Science(Special Post)of Guizhou University(No.2020[27])Guizhou Provincial Science and Technology Projects(No.ZK[2022]041)。
文摘The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphyry(PG).To investigate the mineralization significance of three porphyries,Microthermometry,Laser micro-Raman Spectra,and H-O-He-Ar isotope analyses of fluid inclusions were conducted.Intermediate density with high temperatures(>550℃)and moderate-low salinities(~10 wt.%)characterizes CG-related initial exsolved fluids.Vapor-rich and brine phases separated from the initial fluid following a continuous decrease in pressure and temperature,inducing molybdenite precipitation.FG-related initial fluids are characterized by high temperatures(>550℃)and salinities(>65 wt.%).The mixing of low-salinity fluids led to a rapid decrease in the salinity of FG-related fluid,promoting the deposit of the Mo element.The lead-zinc mineralization is closely related to the FG-related fluid,and the addition of meteoric fluid induced the formation of galena and sphalerite.The ore-forming fluid related to the PG is CO_(2)-rich and accompanied by the addition of mantle-derived He-Ar.The presence of CO_(2) did not contribute to the solubility of Mo,resulting in the absence of a considerable amount of molybdenite.
基金financially supported by the National Key Research&Development Program of China(2025YFE0123800)National Natural Science Foundation of China(No.52372343)+4 种基金Sichuan Transportation Science and Technology Project(2023-A-03)Applied Basic Research Programs of Science and Technology Department in Sichuan Province,China(2022NSFSC1086)Sichuan Science and Technology Program(2024YFHZ0121)the R&D Fund Project of China Academy of Railway Science Corporation Limited(K2024G008)National Natural Science Foundation of China(No.52502430).
文摘Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remains insufficiently explored.This study investigates the dynamic response of a deposit slope containing a weak interlayer through large-scale shaking table tests.The propagation process of the sliding surface was identified using the Hilbert-Huang transform and marginal spectrum analysis.Under seismic excitation,sliding occurs along the interface between the overburden and the weak interlayer,leading to sudden landslide events.Differential vibrations at the overburden-weak interlayer-bedrock interfaces are identified as a primary mechanism driving landslide initiation.As input acceleration increases,these interfacial vibration contrasts intensify,and the acceleration amplification effect within the overburden becomes markedly pronounced.Following landslide occurrence,the vibration differences across interfaces decrease sharply.In the time-frequency domain,seismic waves transmitted through the weak interlayer exhibit amplified low-frequency components.Marginal spectrum analysis of seismic energy evolution within the slope reveals that energy attenuation in the 19-22 Hz frequency band correlates with landslide occurrence,while attenuation in the 9-11 Hz band serves as an indicator for sliding surface propagation and coalescence.For seismic design of deposit slopes with weak interlayers,particular attention should be given to the increased seismic inertial forces in the overburden layer and the detrimental effects of low-frequency wave components on sliding surface development.
基金jointly supported by the National Natural Science Foundation of China(Grant No.42376250)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070402).
文摘Predicting Antarctic sea ice is of substantial academic and practical significance.However,current prediction models,including deep learning(DL)-based models,show notable bias in the marginal ice zone.In this study,we developed a pure data-driven DL model for predicting the Antarctic austral summer monthly-to-seasonal sea ice concentration(SIC)by incorporating a novel hybrid sea ice edge constraint loss function(HybridLoss).The model is referred to as ASICNet.Independent testing based on the last five years(2019–23)demonstrates that ASICNet with HybridLoss achieves significantly higher skill metrics than without,with a reduced mean absolute error of 0.021 from 0.022,a reduced integrated ice edge error of 1.714×10^(6)from 1.794×10^(6)km^(2),but an increased pattern correlation coefficient of 0.40 from 0.38,although both ASICNet versions outperform dynamical and statistical models.Furthermore,enhanced heat maps were developed to interpret the predictability sources of sea ice within DL-based models,and the results suggest that the predictability of Antarctic sea ice is attributable to factors like the Antarctic Dipole(ADP),Amundsen Sea Low(ASL),and Southern Ocean sea surface temperature(SST),as revealed in previous studies.Thus,ASICNet is an efficient tool for austral summer Antarctic SIC prediction.
文摘The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors,an asymptotic test is proposed under the normality assumption of the predictors as well as an asymmetry assumption about the unknown regression mean function.When these assumptions are violated,the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances.
基金National Key R&D Program of China,No.2022YFF1302401National Natural Science Foundation of China,No.42271007。
文摘Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP.
基金Supported by the China National Science and Technology Major Project(2025ZD400801)CNPC Science and Technology Major Project(2023ZZ07-01)。
文摘Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geological,and seismic data,and the intrinsic relationships of hydrocarbon distribution in the passive continental margin basins and the differential hydrocarbon accumulation patterns were analyzed.Results show that basins on both sides of the South Atlantic experienced two major extensional phases—rift and depression—and four evolutionary stages:the Early Cretaceous Berriasian-Barremian intracontinental rift stage,the Early Cretaceous Aptian-Albian intercontinental rift to initial drift transition stage,the Late Cretaceous-Paleogene drift-related marine transgressive depression stage,and the Neogene-Quaternary drift-related marine regressive depression stage.According to basin architecture and superposition style,the passive-margin basins are classified into two principal types:rift-continental marginal depression composite and continental marginal depression-dominated.The basins in the study area were further divided into six types based on the development degree of salt tectonics and the type of dominant sand bodies,i.e.salt-free rift-continental marginal gravity-flow composite type,salt-free rift-continental marginal delta composite type,salt-bearing rift-continental marginal gravity flow composite type,delta-dominated salt-bearing rift-continental marginal delta composite type,gravity-flow-dominated continental marginal depression type,and delta-dominated continental marginal depression type.The salt-free rift-continental marginal gravity flow and delta composite basins are mainly distributed in the southern segment.The salt-bearing rift-continental marginal gravity flow and delta composite basins are mainly distributed in the central segment.The gravity-flow-dominated continental marginal depression basins are mainy distributed in the northern segment.The delta-dominated passive-margin depression basins are distributed in three segments from north to south.In different types of basins,distinctive depositional systems and source-reservoir-caprock assemblages were formed in each upper/lower structure layer.The superimposition and evolution of multi-phase prototype basins result in the orderly hydrocarbon accumulation vertically and laterally,which are“segmented along-strike,zoned across-strike,and layered vertically”.
基金supported by grants from the National Key Research and Development Program of China,Stem Cell and Translational Research(2022YFA1104100,2022YFA1105000,2018YFA0801404)the National Natural Science Foundation of China(82570270,82270230,32130046,82171617,82471689,82170540,82471462,82270566)+8 种基金the Guangdong Basic and Applied Basic Research Foundation(2023B1515020119)the Key Research and Development Program of Guangdong Province(2023B1111050006)the Key Scientific and Technological Program of Guangzhou City(2023B01J1002,202206080002)the Pioneering Talents Project of the Guangzhou Development Zone(2021-L029)the Guangdong Special Support Program(2019BT02Y276)the Shenzhen Science and Technology Program(KJZD20230923114504008)the Sanming Project of Medicine in Shenzhen Nanshan(SZSM2021034008)the Science and Technology Planning Project of Gaozhou(20240619111622)the Special Funds for the Cultivation of Guangdong College Students'Scientific and Technological Innovation(pdjh2025ak003).
文摘Vaccination is the preferred strategy for preventing infections such as influenza in elderly individuals;however,its efficacy is often suboptimal due in part to age-related declines in immune function.In this study,we discovered that the infusion of mesenchymal stromal cells(MSCs)restored defects in the splenic stromal cell network and lymphocyte architecture in aged mice while also increasing specific antibody levels following vaccine immunization.This significantly protected aging mice from influenza infection.Mechanistically,the delivered MSCs localized in the splenic marginal zones,where they positioned themselves near marginal reticular cells(MRCs)and stimulated MRC proliferation,partially through the action of vascular endothelial growth factor A(VEGFA).This MSC‒MRC interaction orchestrated the reconstruction of the stromal network,thereby restoring lymphocyte homeostasis and germinal center reactions.Importantly,the MSC-mediated enhancement of the vaccine response was further validated in aged cynomolgus monkeys.Collectively,our findings provide new insights into the application of MSCs in addressing age-related immune decline and highlight splenic MRCs as critical therapeutic targets.
基金Nankai University Liberal Arts Development Foundation(No.ZB22BZ0309)China Postdoctoral Science Foundation(No.2021M701783).
文摘Eugenics was a discipline founded by the British scholar Galton in 1883 to improve the genetic quality of human beings.When eugenics was introduced to the United States in the early 20th century,it quickly developed into an influential eugenics movement that pointed in new directions to solve the social problems of the United States at that time.In American eugenics movement,eugenicists used family studies to construct the marginalized groups such as the mentally retarded,the poor,and criminals into"hereditary defectives"that would lead to the degradation of the American race.At the same time,they used intelligence tests to demonstrate the"Superiority of the Nordic Race"and to belittle other races,thereby highlighting the dangers of racial mixing.These eugenics discourses provided a plausible justification for segregation,sterilization,and marriage restrictions against marginalized groups in the United States and a"scientific"cloak for restrictive immigration policies,serving as an essential tool for exclusionists to gain support from policymakers and the public.
