Due to their high density,the ilmenite-bearing cumulates(IBC)(with or without KREEP)formed during the late-stage lunar magma ocean solidification are thought to sink into the underlying lunar mantle and trigger lunar ...Due to their high density,the ilmenite-bearing cumulates(IBC)(with or without KREEP)formed during the late-stage lunar magma ocean solidification are thought to sink into the underlying lunar mantle and trigger lunar mantle overturn.Geophysical evidence implied that IBC may descend deep inside the Moon and remain as a partially molten layer at the core-mantle boundary(CMB).However,partial melting may have occurred on the mixed mantle cumulates during the sinking of IBC/KREEP and the silicate melt may be positively buoyant,thus preventing the IBC/KREEP layer from sinking to the CMB.Here,we perform thermodynamic simulation on the stability of lunar mantle cumulates at different depths mixed with different amounts of IBC/KREEP from an updated LMO model.The modeling results suggest that the sinking of IBC/KREEP will cause at least 5 wt%partial melting in the shallow(~120 km)and a much larger degree of partial melting in the deep lunar mantle(~420 km).Due to the density contrast with the surrounding mantle,IBC/KREEP-bearing melts could potentially decouple under certain conditions.The modified lunar mantle by sinking of IBC/KREEP can better explain the formation of different kinds of lunar basaltic magma than the primary lunar mantle formed through differentiation of lunar magma ocean.Sinking of IBC/KREEP back into the lunar mantle may introduce plagioclase,clinopyroxene,garnet,and incompatible radioactive elements into the deep lunar mantle,which will further affect the thermal and chemical evolution of the lunar interior.展开更多
Essential proteins are inseparable in cell growth and survival. The study of essential proteins is important for understanding cellular functions and biological mechanisms. Therefore, various computable methods have b...Essential proteins are inseparable in cell growth and survival. The study of essential proteins is important for understanding cellular functions and biological mechanisms. Therefore, various computable methods have been proposed to identify essential proteins. Unfortunately, most methods based on network topology only consider the interactions between a protein and its neighboring proteins, and not the interactions with its higher-order distance proteins. In this paper, we propose the DSEP algorithm in which we integrated network topology properties and subcellular localization information in protein–protein interaction(PPI) networks based on four-order distances, and then used random walks to identify the essential proteins. We also propose a method to calculate the finite-order distance of the network, which can greatly reduce the time complexity of our algorithm. We conducted a comprehensive comparison of the DSEP algorithm with 11 existing classical algorithms to identify essential proteins with multiple evaluation methods. The results show that DSEP is superior to these 11 methods.展开更多
BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations ...BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.展开更多
This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularl...This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularly multiplication and division. The operations of multiplication and division are represented by algebraic formulas. An advantage of the method is that the cumulative process can be performed on decimal numbers. The present paper aims to establish a basic and useful formula valid for the two fundamental arithmetic operations of multiplication and division. The new cumulative method proved to be more flexible and made it possible to extend the multiplication and division based on repeated addition/subtraction to decimal numbers.展开更多
The non-Gaussianity of quantum states incarnates an important resource for improving the performance of continuous-variable quantum information protocols.We propose a novel criterion of non-Gaussianity for single-mode...The non-Gaussianity of quantum states incarnates an important resource for improving the performance of continuous-variable quantum information protocols.We propose a novel criterion of non-Gaussianity for single-mode rotationally symmetric quantum states via the squared Frobenius norm of higher-order cumulant matrix for the quadrature distribution function.As an application,we study the non-Gaussianities of three classes of single-mode symmetric non-Gaussian states:a mixture of vacuum and Fock states,single-photon added thermal states,and even/odd Schr¨odinger cat states.It is shown that such a criterion is faithful and effective for revealing non-Gaussianity.We further extend this criterion to two cases of symmetric multi-mode non-Gaussian states and non-symmetric single-mode non-Gaussian states.展开更多
Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects an...Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects and cumulative effects of repeated blasts.Therefore,rats were used as the experimental samples to suffer from explosion blasts with different peak air overpressures(167 kPa~482 kPa)and varying number of repeated blasts.The cumulative effect of craniocerebral trauma was most pronounced for moderate repeated blast,showing approximately 95%increase of trauma severity with penta blast,and an approximately 85%increase of trauma severity with penta minor blast.The cumulative effect of craniocerebral trauma from severe,repeated blast has a smaller rate of change compared to the other two conditions.The severity of trauma from penta blast increased by approximately 69%compared to a single blast.Comprehensive physiological,pathological and biochemical analysis show that the degree of neurological trauma caused by repeated blasts is higher than that of single blasts,and the pathological trauma to brain tissue is more extensive and severe.The trauma degree remains unchanged after double blast,increases by one grade after triple or quadruple blast,and increases by two grades after penta blast.展开更多
To conveniently calculate the Wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive t...To conveniently calculate the Wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive the general evolution formula of the Wigner function, and its relation to Weyl correspondence is also discussed. The method of integration within the ordered product of operators is essential to our discussion.展开更多
Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop w...Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop water status.With three-year field experiments with winter wheat,encompassing two irrigation levels(rainfed and irrigation at jointing and anthesis)and three N levels(0,180,and 270 kg ha1),this study aims to establish a novel approach for determining the Nc dilution curve based on crop cumulative transpiration(T),providing a comprehensive analysis of the interaction between N and water availability.The Nc curves derived from both crop dry matter(DM)and T demonstrated N concentration dilution under different conditions with different parameters.The equation Nc=6.43T0.24 established a consistent relationship across varying irrigation regimes.Independent test results indicated that the nitrogen nutrition index(NNI),calculated from this curve,effectively identifies and quantifies the two sources of N deficiency:insufficient N supply in the soil and insufficient soil water concentration leading to decreased N availability for root absorption.Additionally,the NNI calculated from the Nc-DM and Nc-T curves exhibited a strong negative correlation with accumulated N deficit(Nand)and a positive correlation with relative grain yield(RGY).The NNI derived from the Nc-T curve outperformed the NNI derived from the Nc-DM curve concerning its relationship with Nand and RGY,as indicated by larger R2 values and smaller AIC.The novel Nc curve based on T serves as an effective diagnostic tool for assessing winter wheat N status,predicting grain yield,and optimizing N fertilizer management across varying irrigation conditions.These findings would provide new insights and methods to improve the simulations of water-N interaction relationship in crop growth models.展开更多
Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developm...Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developments at risk.This study assessed the cumulative impacts of air emissions from 22 major power plants in southeast Bangladesh planned to generate 21,550 MW of electricity.It also includes anticipated growth in small to medium size industries,brickfields,highway traffic,inland water transport,transhippers,jetty,and vessel transports used for transporting fuel resources for these power plants.A 50 km by 50 km airshed is considered for air quality modeling.Cumulative analysis indicates that predicted MGLCs(Maximum Ground Level Concentrations)of NO2 and CO are complying with both Bangladesh NAAQS(National Ambient Air Quality Standards)and WBG(World Bank Group)Guidelines.The daily average MGLC of PM_(2.5)(62.45µg/m^(3))from all sources complies with NAAQS,however,exceeds the WBG Guidelines.Annual PM_(2.5) concentration(15.45µg/m^(3))exceeds NAAQS and WBG Guidelines.The PM10 concentration complies with the NAAQS for both 24-hour and annual averaging times.Annual average concentration(23.12µg/m^(3))exceeds WBG Guidelines.Daily average SO2 concentration(102.49µg/m^(3))complies with the NAAQS however,it exceeds the WBG guideline values.High concentrations of PM_(2.5) and SO2 are due to the contribution of transboundary emissions and secondary pollutants in the atmosphere.This dispersion modeling outcome can be used by the policymakers for the pollution reduction strategy.展开更多
The G?ksun(Kahramanmaras)ophiolite(GKO),cropping out in a tectonic window bounded by the Malatya metamorphic unit on both the north and south,is located in the EW-trending lower nappe zone of the southeast Anatolian o...The G?ksun(Kahramanmaras)ophiolite(GKO),cropping out in a tectonic window bounded by the Malatya metamorphic unit on both the north and south,is located in the EW-trending lower nappe zone of the southeast Anatolian orogenic belt(Turkey).It exhibits a complete oceanic lithospheric section and overlies the Middle Eocene Maden Group/Complex with a tectonic contact at its base.The ophiolitic rocks and the tectonically overlying Malatya metamorphic(continental)unit were intruded by I-type calc-alkaline Late Cretaceous granitoid(~81-84 Ma).The ultramafic to cumulates in the GKO are represented by wehrlite,plagioclase wehrlite,olivine gabbro and gabbro.The crystallization order for the cumulate rocks is as follows:olivine±chromian spinel→clinopyroxene→plagioclase.The major and trace element geochemistry as well as the mineral chemistry of the ultramafic to mafic cumulate rocks suggest that the primary magma generating the GKO is compositionally similar to that observed in the modern island-arc tholeiitic sequences.The mineral chemistry of the ultramafic to mafic cumulates indicates that they were derived from a mantle source that was previously depleted by earlier partial melting events.The highly magnesian olivine(Fo77-83),clinopyroxene(Mg#of 82-90)and the highly Ca-plagioclase(An81-89)exhibit a close similarity to those,which formed in a supra-subduction zone(SSZ)setting.The field and the geochemical evidence suggest that the GKO formed as part of a much larger sheet of oceanic lithosphere,which accreted to the base of the Tauride active continental margin,including the ispendere,K?mürhan and the Guleman ophiolites.The latter were contemporaneous and genetically/tectonically related within the same SSZ setting during the closure of the Neotethyan oceanic basin(Berit Ocean)between the Taurides to the north and the Bitlis-Pütürge massif to the south during the Late Cretaceous.展开更多
The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great sign...The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.展开更多
Objective Sulfide inclusions within natural mineral phases play important roles in exploring the origin of magmatic sulfides ores,tracing the distribution of sulfur in mantle or crust and understanding continental man...Objective Sulfide inclusions within natural mineral phases play important roles in exploring the origin of magmatic sulfides ores,tracing the distribution of sulfur in mantle or crust and understanding continental mantle evolution(partial melting and metasomatism in upper mantle).Until now,varieties of sulfide inclusions have been extensively discovered in the ultramafic or mafic phenocrysts.展开更多
Aqueous zinc metal batteries feature intrinsic safety,but suffer from severe dendrite growth and water-derived side reactions.Many metal coatings have been explored for stabilizing Zn metal anode via a trialand-error ...Aqueous zinc metal batteries feature intrinsic safety,but suffer from severe dendrite growth and water-derived side reactions.Many metal coatings have been explored for stabilizing Zn metal anode via a trialand-error approach.Here,we propose an exercisable way to screen the potential metal coating on Zn anodes in view of de-polarization effect and dendrite-suppressing ability theoretically.As an output of this screening,cadmium(Cd) metal is checked experimentally.Therefore,symmetric ZnllZn cells using Cd coated Zn(Zn@Cd) exhibit an ultra-long cycle life of 3500 h(nearly 5 months) at a high current density of 10 mA cm^(-2),achieving a record-high cumulative capacity(35 A h cm^(-2)) compared to the previous reports.The full cells of Zn@Cd‖MnO_(2) display a markedly improved cycling performance under harsh conditions including a limited Zn supply(N/P ratio=1.7) and a high areal capacity(3.5 mA h cm^(-2)).The significance of this work lies in not only the first report of Cd coating for stabilizing Zn metal anode,but also a feasible way to screen the promising metal materials for other metal anodes.展开更多
The Late Cretaceous Sabzevar ophiolite represents one of the largest and most complete fragments of Tethyan oceanic lithosphere in the NE Iran.It is mainly composed of serpentinized mantle peridotites slices;nonethele...The Late Cretaceous Sabzevar ophiolite represents one of the largest and most complete fragments of Tethyan oceanic lithosphere in the NE Iran.It is mainly composed of serpentinized mantle peridotites slices;nonetheless,minor tectonic slices of all crustal sequence constituents are observed in this ophiolite.The crustal sequence contains a well-developed ultramafic and mafic cumulates section,comprising plagioclase-bearing wehrlite,olivine clinopyroxenite,olivine gabbronorite,gabbronorite,amphibole gabbronorite and quartz gabbronorite with adcumulate,mesocumulate,heteradcumulate and orthocumulate textures.The crystallization order for these rocks is olivine±chromian spinel→clinopyroxene→plagioclase→orthopyroxene→amphibole.The presence of primary magmatic amphiboles in the cumulate rocks shows that the parent magma evolved under hydrous conditions.Geochemically,the studied rock units are characterized by low TiO2(0.18-0.57 wt.%),P2 O5(<0.05 wt.%),K2 O(0.01-0.51 wt.%)and total alkali contents(0.12-3.04 wt.%).They indicate fractionated trends in the chondrite-normalized rare earth element(REE)plots and multi-element diagrams(spider diagrams).The general trend of the spider diagrams exhibit slight enrichment in large ion lithophile elements(LILEs)relative to high field strength elements(HFSEs)and positive anomalies in Sr,Pb and Eu and negative anomalies in Zr and Nb relative to the adjacent elements.The REE plots of these rocks display increasing trend from La to Sm,positive Eu anomaly(Eu/Eu*=1.06-1.54)and an almost flat pattern from medium REE(MREE)to heavy REE(HREE)region[(Gd/Yb)N=1-1.17].Moreover,clinopyroxenes from the cumulate rocks have low REE contents and show marked depletion in light REE(LREE)compared to MREE and HREE[(La/Sm)N=0.10-0.27 and(La/Yb)N=0.08-0.22].The composition of calculated melts in equilibrium with the clinopyroxenes from less evolved cumulate samples are closely similar to island arc tholeiitic(IAT)magmas.Modal mineralogy,geochemical features and REE modeling indicate that Sabzevar cumulate rocks were formed by crystal accumulation from a hydrous depleted basaltic melt with IAT affinity.This melt has been produced by moderate to high degree(~15%)of partial melting a depleted mantle source,which partially underwent metasomatic enrichment from subducted slab components in an intra-oceanic arc setting.展开更多
Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of ...Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of inappropriate exposure to different antimicrobials in resistant Pseudomonas aeruginosa infection could help in elucidating the effective approach towards using antimicrobials in vulnerable patients with CRPA infection.Object:To investigate the association between exposure ofβ-lactam antimicrobials and CRPA infection relative to control patients.Methods:The MEDLINE/PubMed and OVID/Embase databases were used to search case-control and cohort studies in English language which reported antimicrobial exposure as risk factors for CRPA infection.The pooled odds ratios(OR)were calculated using a random-effect and fixed-effect model,and forest plots from a cumulative meta-analysis method were used to better show how pooled OR changed as updated evidence accumulated.Results:A total of 24 studies comprising 7039 participants were included for cumulative meta-analysis.A positive correlation was found between development of CRPA infection and exposure of beta-lactam antimicrobials:carbapenems(OR=7.60,95%CI:3.95 to 14.62,P<0.0001),imipenem(OR=9.81,95%CI:5.56 to 17.33),ampicillin(OR=1.86,95%CI:1.14 to 2.41),piperacillin(OR=2.82,95%CI:1.46 to 2.43),penicillins(OR=1.42,95%CI:0.90 to 2.24),cephalosporins(OR=1.88,95%CI:1.46 to 2.43)andβlactamase inhibitors(OR=1.96,95%CI:1.44 to 2.67).Further,exposure of other antimicrobial agents like quinolone(OR=2.35,95%CI:1.78 to 3.10),ciprofloxacin(OR=2.35,95%CI:1.66 to 3.95),aminoglycoside(OR=2.17,95%CI:1.60 to 2.95),amikacin(OR=3.11,95%CI:2.10 to 4.61),glycopeptides(OR=3.02,95%CI:1.92 to 4.75)and vancomycin(OR=3.26,95%CI:1.48 to 7.18),were also found to be positively associated with development of CRPA infection.Conclusions:Exposure of all kinds ofβ-lactams is significantly associated with development of carbapenemresistant Pseudomonas aeruginosa infection.These findings provide an impetus to take a more active approach while usingβ-lactam antimicrobials in patients with resistant Pseudomonas aeruginosa infections.展开更多
The Neotethys plays an important role in shaping the Gangdese magmatic belt,southern Tibet.However,the initial time of spreading and subduction of the Neotethys remains contentious.In this study,a suite of late Triass...The Neotethys plays an important role in shaping the Gangdese magmatic belt,southern Tibet.However,the initial time of spreading and subduction of the Neotethys remains contentious.In this study,a suite of late Triassic cumulate hornblende gabbro was identified in the southern margin of the Gangdese magmatic belt.The gabbro exhibits cumulate structure,with hornblende and plagioclase as the primary mineral phases.Isotopic data indicate a hydrous magma source derived from a depleted mantle wedge that has been modified by slab dehydration.Geochemical discriminations suggest that the gabbro was formed in an intraoceanic arc setting,with crystallization ages of ca.220-213 Ma.Hornblende,hornblendelagioclase and ilmenite thermometers reveal that the crystallization temperature of 900-750°C for the gabbro.Hornblende and hornblende-plagioclase geobarometers yield an emplacement depth at ca.14.5-19.5 km.This gabbro constitutes a line of evidence for an intraoceanic arc magmatism that is coeval with the counterparts in the southern Turkey,revealing an intraoceanic subduction system within the Neotethys from west to east in the Late Triassic and that the oceanization of the Neotethys was much earlier than previous expectation.展开更多
A cross-sectional exploratory assessment of the needs and challenges of petroleum industry in Nigeria, in assessing process safety cumulative risk for major accidents prevention was investigated. A purposive cum rando...A cross-sectional exploratory assessment of the needs and challenges of petroleum industry in Nigeria, in assessing process safety cumulative risk for major accidents prevention was investigated. A purposive cum random sampling technique was used in this study, among selected petroleum companies operating in Nigeria. Survey questionnaires were received from 216 participants made up of asset integrity engineers/operators, process safety experts, production safety professionals in the petroleum industry in Nigeria. Data analyses were carried out to cover descriptive and inferential statistics. Overall, the study recognized that assessing process safety cumulative risk is not a simple process due largely to the changing nature of safety critical barriers degradation data. The study result showed four main challenges faced by petroleum industries in Nigeria, in assessing process safety cumulative risk: 1) the study showed that 94% of the respondents agreed that there is limited accessibility to safety critical barriers degradation data (little automation). Also 2) 94% of the respondents accounted for poor knowledge of process safety cumulative risk is and agreed it to be of low rating. The result further showed that 3) 90% of the respondents demonstrated that there are no guidance and procedures in assessing process safety cumulative risk and finally 4) 92% of the respondents reported that there is no real-time risk visualization model/ tool. Addressing these issues and challenges by the petroleum industries in the study area, will lead to successful assessment of process safety cumulative risk, thereby reducing the risk of major accidents.展开更多
Due to the complex and changeable environment under water,the performance of traditional DOA estimation algorithms based on mathematical model,such as MUSIC,ESPRIT,etc.,degrades greatly or even some mistakes can be ma...Due to the complex and changeable environment under water,the performance of traditional DOA estimation algorithms based on mathematical model,such as MUSIC,ESPRIT,etc.,degrades greatly or even some mistakes can be made because of the mismatch between algorithm model and actual environment model.In addition,the neural network has the ability of generalization and mapping,it can consider the noise,transmission channel inconsistency and other factors of the objective environment.Therefore,this paper utilizes Back Propagation(BP)neural network as the basic framework of underwater DOA estimation.Furthermore,in order to improve the performance of DOA estimation of BP neural network,the following three improvements are proposed.(1)Aiming at the problem that the weight and threshold of traditional BP neural network converge slowly and easily fall into the local optimal value in the iterative process,PSO-BP-NN based on optimized particle swarm optimization(PSO)algorithm is proposed.(2)The Higher-order cumulant of the received signal is utilized to establish the training model.(3)A BP neural network training method for arbitrary number of sources is proposed.Finally,the effectiveness of the proposed algorithm is proved by comparing with the state-of-the-art algorithms and MUSIC algorithm.展开更多
To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical ca...To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas.展开更多
基金funded by the National Natural Science Foundation of China(41773052,41973058)。
文摘Due to their high density,the ilmenite-bearing cumulates(IBC)(with or without KREEP)formed during the late-stage lunar magma ocean solidification are thought to sink into the underlying lunar mantle and trigger lunar mantle overturn.Geophysical evidence implied that IBC may descend deep inside the Moon and remain as a partially molten layer at the core-mantle boundary(CMB).However,partial melting may have occurred on the mixed mantle cumulates during the sinking of IBC/KREEP and the silicate melt may be positively buoyant,thus preventing the IBC/KREEP layer from sinking to the CMB.Here,we perform thermodynamic simulation on the stability of lunar mantle cumulates at different depths mixed with different amounts of IBC/KREEP from an updated LMO model.The modeling results suggest that the sinking of IBC/KREEP will cause at least 5 wt%partial melting in the shallow(~120 km)and a much larger degree of partial melting in the deep lunar mantle(~420 km).Due to the density contrast with the surrounding mantle,IBC/KREEP-bearing melts could potentially decouple under certain conditions.The modified lunar mantle by sinking of IBC/KREEP can better explain the formation of different kinds of lunar basaltic magma than the primary lunar mantle formed through differentiation of lunar magma ocean.Sinking of IBC/KREEP back into the lunar mantle may introduce plagioclase,clinopyroxene,garnet,and incompatible radioactive elements into the deep lunar mantle,which will further affect the thermal and chemical evolution of the lunar interior.
基金Project supported by the Gansu Province Industrial Support Plan (Grant No.2023CYZC-25)the Natural Science Foundation of Gansu Province (Grant No.23JRRA770)the National Natural Science Foundation of China (Grant No.62162040)。
文摘Essential proteins are inseparable in cell growth and survival. The study of essential proteins is important for understanding cellular functions and biological mechanisms. Therefore, various computable methods have been proposed to identify essential proteins. Unfortunately, most methods based on network topology only consider the interactions between a protein and its neighboring proteins, and not the interactions with its higher-order distance proteins. In this paper, we propose the DSEP algorithm in which we integrated network topology properties and subcellular localization information in protein–protein interaction(PPI) networks based on four-order distances, and then used random walks to identify the essential proteins. We also propose a method to calculate the finite-order distance of the network, which can greatly reduce the time complexity of our algorithm. We conducted a comprehensive comparison of the DSEP algorithm with 11 existing classical algorithms to identify essential proteins with multiple evaluation methods. The results show that DSEP is superior to these 11 methods.
基金National Natural Science Foundation of China,No.72101236China Postdoctoral Science Foundation,No.2022M722900+1 种基金Collaborative Innovation Project of Zhengzhou City,No.XTCX2023006Nursing Team Project of the First Affiliated Hospital of Zhengzhou University,No.HLKY2023005.
文摘BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.
文摘This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularly multiplication and division. The operations of multiplication and division are represented by algebraic formulas. An advantage of the method is that the cumulative process can be performed on decimal numbers. The present paper aims to establish a basic and useful formula valid for the two fundamental arithmetic operations of multiplication and division. The new cumulative method proved to be more flexible and made it possible to extend the multiplication and division based on repeated addition/subtraction to decimal numbers.
基金Project supported by the Natural Science Foundation of Hunan Province of China(Grant No.2021JJ30535)。
文摘The non-Gaussianity of quantum states incarnates an important resource for improving the performance of continuous-variable quantum information protocols.We propose a novel criterion of non-Gaussianity for single-mode rotationally symmetric quantum states via the squared Frobenius norm of higher-order cumulant matrix for the quadrature distribution function.As an application,we study the non-Gaussianities of three classes of single-mode symmetric non-Gaussian states:a mixture of vacuum and Fock states,single-photon added thermal states,and even/odd Schr¨odinger cat states.It is shown that such a criterion is faithful and effective for revealing non-Gaussianity.We further extend this criterion to two cases of symmetric multi-mode non-Gaussian states and non-symmetric single-mode non-Gaussian states.
基金supported by the National Natural Science Foundation of China(Grant No.12372356)Postgraduate Scientific Research In-novation Project of Hunan Province(Grant No.CX20221044).
文摘Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects and cumulative effects of repeated blasts.Therefore,rats were used as the experimental samples to suffer from explosion blasts with different peak air overpressures(167 kPa~482 kPa)and varying number of repeated blasts.The cumulative effect of craniocerebral trauma was most pronounced for moderate repeated blast,showing approximately 95%increase of trauma severity with penta blast,and an approximately 85%increase of trauma severity with penta minor blast.The cumulative effect of craniocerebral trauma from severe,repeated blast has a smaller rate of change compared to the other two conditions.The severity of trauma from penta blast increased by approximately 69%compared to a single blast.Comprehensive physiological,pathological and biochemical analysis show that the degree of neurological trauma caused by repeated blasts is higher than that of single blasts,and the pathological trauma to brain tissue is more extensive and severe.The trauma degree remains unchanged after double blast,increases by one grade after triple or quadruple blast,and increases by two grades after penta blast.
基金Project supported by the Foundation for Young Talents in College of Anhui Province, China (Grant Nos. gxyq2021210 and gxyq2019077)the Natural Science Foundation of the Anhui Higher Education Institutions, China (Grant Nos. 2022AH051580 and 2022AH051586)。
文摘To conveniently calculate the Wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive the general evolution formula of the Wigner function, and its relation to Weyl correspondence is also discussed. The method of integration within the ordered product of operators is essential to our discussion.
基金supported by the National Key Research and Development Program of China(2022YFD2001005)the Key Research&Development Program of Jiangsu province(BE2021358)+2 种基金the National Natural Science Foundation of China(32271989)the Natural Science Foundation of Jiangsu province(BK20220146)the Jiangsu Independent Innovation Fund Project of Agricultural Science and Technology[CX(23)3121].
文摘Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop water status.With three-year field experiments with winter wheat,encompassing two irrigation levels(rainfed and irrigation at jointing and anthesis)and three N levels(0,180,and 270 kg ha1),this study aims to establish a novel approach for determining the Nc dilution curve based on crop cumulative transpiration(T),providing a comprehensive analysis of the interaction between N and water availability.The Nc curves derived from both crop dry matter(DM)and T demonstrated N concentration dilution under different conditions with different parameters.The equation Nc=6.43T0.24 established a consistent relationship across varying irrigation regimes.Independent test results indicated that the nitrogen nutrition index(NNI),calculated from this curve,effectively identifies and quantifies the two sources of N deficiency:insufficient N supply in the soil and insufficient soil water concentration leading to decreased N availability for root absorption.Additionally,the NNI calculated from the Nc-DM and Nc-T curves exhibited a strong negative correlation with accumulated N deficit(Nand)and a positive correlation with relative grain yield(RGY).The NNI derived from the Nc-T curve outperformed the NNI derived from the Nc-DM curve concerning its relationship with Nand and RGY,as indicated by larger R2 values and smaller AIC.The novel Nc curve based on T serves as an effective diagnostic tool for assessing winter wheat N status,predicting grain yield,and optimizing N fertilizer management across varying irrigation conditions.These findings would provide new insights and methods to improve the simulations of water-N interaction relationship in crop growth models.
文摘Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developments at risk.This study assessed the cumulative impacts of air emissions from 22 major power plants in southeast Bangladesh planned to generate 21,550 MW of electricity.It also includes anticipated growth in small to medium size industries,brickfields,highway traffic,inland water transport,transhippers,jetty,and vessel transports used for transporting fuel resources for these power plants.A 50 km by 50 km airshed is considered for air quality modeling.Cumulative analysis indicates that predicted MGLCs(Maximum Ground Level Concentrations)of NO2 and CO are complying with both Bangladesh NAAQS(National Ambient Air Quality Standards)and WBG(World Bank Group)Guidelines.The daily average MGLC of PM_(2.5)(62.45µg/m^(3))from all sources complies with NAAQS,however,exceeds the WBG Guidelines.Annual PM_(2.5) concentration(15.45µg/m^(3))exceeds NAAQS and WBG Guidelines.The PM10 concentration complies with the NAAQS for both 24-hour and annual averaging times.Annual average concentration(23.12µg/m^(3))exceeds WBG Guidelines.Daily average SO2 concentration(102.49µg/m^(3))complies with the NAAQS however,it exceeds the WBG guideline values.High concentrations of PM_(2.5) and SO2 are due to the contribution of transboundary emissions and secondary pollutants in the atmosphere.This dispersion modeling outcome can be used by the policymakers for the pollution reduction strategy.
基金supported by TüBITAK (YDABCAG199Y011) and the Cukurova University Scientific Research Projects (MMF2002BAP41)the Open Fund (GPMR201702) of State Key Lab of Geological Processes and Mineral Resources,China University of Geosciences,Wuhansubsidy by the Russian Government to support the Program of competitive growth of Kazan Federal University
文摘The G?ksun(Kahramanmaras)ophiolite(GKO),cropping out in a tectonic window bounded by the Malatya metamorphic unit on both the north and south,is located in the EW-trending lower nappe zone of the southeast Anatolian orogenic belt(Turkey).It exhibits a complete oceanic lithospheric section and overlies the Middle Eocene Maden Group/Complex with a tectonic contact at its base.The ophiolitic rocks and the tectonically overlying Malatya metamorphic(continental)unit were intruded by I-type calc-alkaline Late Cretaceous granitoid(~81-84 Ma).The ultramafic to cumulates in the GKO are represented by wehrlite,plagioclase wehrlite,olivine gabbro and gabbro.The crystallization order for the cumulate rocks is as follows:olivine±chromian spinel→clinopyroxene→plagioclase.The major and trace element geochemistry as well as the mineral chemistry of the ultramafic to mafic cumulate rocks suggest that the primary magma generating the GKO is compositionally similar to that observed in the modern island-arc tholeiitic sequences.The mineral chemistry of the ultramafic to mafic cumulates indicates that they were derived from a mantle source that was previously depleted by earlier partial melting events.The highly magnesian olivine(Fo77-83),clinopyroxene(Mg#of 82-90)and the highly Ca-plagioclase(An81-89)exhibit a close similarity to those,which formed in a supra-subduction zone(SSZ)setting.The field and the geochemical evidence suggest that the GKO formed as part of a much larger sheet of oceanic lithosphere,which accreted to the base of the Tauride active continental margin,including the ispendere,K?mürhan and the Guleman ophiolites.The latter were contemporaneous and genetically/tectonically related within the same SSZ setting during the closure of the Neotethyan oceanic basin(Berit Ocean)between the Taurides to the north and the Bitlis-Pütürge massif to the south during the Late Cretaceous.
基金supported by the Science and Technology Research Project to Henan Provincial Department of Natural Resources(Henan Natural Resources Letter[2019]373–10)。
文摘The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.
基金financially supported by the National Natural Science Foundation of China(grant No. 41302062)the China Geological Survey(grant No. 12120115034401)
文摘Objective Sulfide inclusions within natural mineral phases play important roles in exploring the origin of magmatic sulfides ores,tracing the distribution of sulfur in mantle or crust and understanding continental mantle evolution(partial melting and metasomatism in upper mantle).Until now,varieties of sulfide inclusions have been extensively discovered in the ultramafic or mafic phenocrysts.
基金supported by the National Nature Science Foundation of China (22105118)the Nature Science Foundation of Shandong Provinces (ZR2021QB095)the China Postdoctoral Science Foundation (2020TQ0183 and 2021M701979)。
文摘Aqueous zinc metal batteries feature intrinsic safety,but suffer from severe dendrite growth and water-derived side reactions.Many metal coatings have been explored for stabilizing Zn metal anode via a trialand-error approach.Here,we propose an exercisable way to screen the potential metal coating on Zn anodes in view of de-polarization effect and dendrite-suppressing ability theoretically.As an output of this screening,cadmium(Cd) metal is checked experimentally.Therefore,symmetric ZnllZn cells using Cd coated Zn(Zn@Cd) exhibit an ultra-long cycle life of 3500 h(nearly 5 months) at a high current density of 10 mA cm^(-2),achieving a record-high cumulative capacity(35 A h cm^(-2)) compared to the previous reports.The full cells of Zn@Cd‖MnO_(2) display a markedly improved cycling performance under harsh conditions including a limited Zn supply(N/P ratio=1.7) and a high areal capacity(3.5 mA h cm^(-2)).The significance of this work lies in not only the first report of Cd coating for stabilizing Zn metal anode,but also a feasible way to screen the promising metal materials for other metal anodes.
文摘The Late Cretaceous Sabzevar ophiolite represents one of the largest and most complete fragments of Tethyan oceanic lithosphere in the NE Iran.It is mainly composed of serpentinized mantle peridotites slices;nonetheless,minor tectonic slices of all crustal sequence constituents are observed in this ophiolite.The crustal sequence contains a well-developed ultramafic and mafic cumulates section,comprising plagioclase-bearing wehrlite,olivine clinopyroxenite,olivine gabbronorite,gabbronorite,amphibole gabbronorite and quartz gabbronorite with adcumulate,mesocumulate,heteradcumulate and orthocumulate textures.The crystallization order for these rocks is olivine±chromian spinel→clinopyroxene→plagioclase→orthopyroxene→amphibole.The presence of primary magmatic amphiboles in the cumulate rocks shows that the parent magma evolved under hydrous conditions.Geochemically,the studied rock units are characterized by low TiO2(0.18-0.57 wt.%),P2 O5(<0.05 wt.%),K2 O(0.01-0.51 wt.%)and total alkali contents(0.12-3.04 wt.%).They indicate fractionated trends in the chondrite-normalized rare earth element(REE)plots and multi-element diagrams(spider diagrams).The general trend of the spider diagrams exhibit slight enrichment in large ion lithophile elements(LILEs)relative to high field strength elements(HFSEs)and positive anomalies in Sr,Pb and Eu and negative anomalies in Zr and Nb relative to the adjacent elements.The REE plots of these rocks display increasing trend from La to Sm,positive Eu anomaly(Eu/Eu*=1.06-1.54)and an almost flat pattern from medium REE(MREE)to heavy REE(HREE)region[(Gd/Yb)N=1-1.17].Moreover,clinopyroxenes from the cumulate rocks have low REE contents and show marked depletion in light REE(LREE)compared to MREE and HREE[(La/Sm)N=0.10-0.27 and(La/Yb)N=0.08-0.22].The composition of calculated melts in equilibrium with the clinopyroxenes from less evolved cumulate samples are closely similar to island arc tholeiitic(IAT)magmas.Modal mineralogy,geochemical features and REE modeling indicate that Sabzevar cumulate rocks were formed by crystal accumulation from a hydrous depleted basaltic melt with IAT affinity.This melt has been produced by moderate to high degree(~15%)of partial melting a depleted mantle source,which partially underwent metasomatic enrichment from subducted slab components in an intra-oceanic arc setting.
文摘Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of inappropriate exposure to different antimicrobials in resistant Pseudomonas aeruginosa infection could help in elucidating the effective approach towards using antimicrobials in vulnerable patients with CRPA infection.Object:To investigate the association between exposure ofβ-lactam antimicrobials and CRPA infection relative to control patients.Methods:The MEDLINE/PubMed and OVID/Embase databases were used to search case-control and cohort studies in English language which reported antimicrobial exposure as risk factors for CRPA infection.The pooled odds ratios(OR)were calculated using a random-effect and fixed-effect model,and forest plots from a cumulative meta-analysis method were used to better show how pooled OR changed as updated evidence accumulated.Results:A total of 24 studies comprising 7039 participants were included for cumulative meta-analysis.A positive correlation was found between development of CRPA infection and exposure of beta-lactam antimicrobials:carbapenems(OR=7.60,95%CI:3.95 to 14.62,P<0.0001),imipenem(OR=9.81,95%CI:5.56 to 17.33),ampicillin(OR=1.86,95%CI:1.14 to 2.41),piperacillin(OR=2.82,95%CI:1.46 to 2.43),penicillins(OR=1.42,95%CI:0.90 to 2.24),cephalosporins(OR=1.88,95%CI:1.46 to 2.43)andβlactamase inhibitors(OR=1.96,95%CI:1.44 to 2.67).Further,exposure of other antimicrobial agents like quinolone(OR=2.35,95%CI:1.78 to 3.10),ciprofloxacin(OR=2.35,95%CI:1.66 to 3.95),aminoglycoside(OR=2.17,95%CI:1.60 to 2.95),amikacin(OR=3.11,95%CI:2.10 to 4.61),glycopeptides(OR=3.02,95%CI:1.92 to 4.75)and vancomycin(OR=3.26,95%CI:1.48 to 7.18),were also found to be positively associated with development of CRPA infection.Conclusions:Exposure of all kinds ofβ-lactams is significantly associated with development of carbapenemresistant Pseudomonas aeruginosa infection.These findings provide an impetus to take a more active approach while usingβ-lactam antimicrobials in patients with resistant Pseudomonas aeruginosa infections.
文摘The Neotethys plays an important role in shaping the Gangdese magmatic belt,southern Tibet.However,the initial time of spreading and subduction of the Neotethys remains contentious.In this study,a suite of late Triassic cumulate hornblende gabbro was identified in the southern margin of the Gangdese magmatic belt.The gabbro exhibits cumulate structure,with hornblende and plagioclase as the primary mineral phases.Isotopic data indicate a hydrous magma source derived from a depleted mantle wedge that has been modified by slab dehydration.Geochemical discriminations suggest that the gabbro was formed in an intraoceanic arc setting,with crystallization ages of ca.220-213 Ma.Hornblende,hornblendelagioclase and ilmenite thermometers reveal that the crystallization temperature of 900-750°C for the gabbro.Hornblende and hornblende-plagioclase geobarometers yield an emplacement depth at ca.14.5-19.5 km.This gabbro constitutes a line of evidence for an intraoceanic arc magmatism that is coeval with the counterparts in the southern Turkey,revealing an intraoceanic subduction system within the Neotethys from west to east in the Late Triassic and that the oceanization of the Neotethys was much earlier than previous expectation.
文摘A cross-sectional exploratory assessment of the needs and challenges of petroleum industry in Nigeria, in assessing process safety cumulative risk for major accidents prevention was investigated. A purposive cum random sampling technique was used in this study, among selected petroleum companies operating in Nigeria. Survey questionnaires were received from 216 participants made up of asset integrity engineers/operators, process safety experts, production safety professionals in the petroleum industry in Nigeria. Data analyses were carried out to cover descriptive and inferential statistics. Overall, the study recognized that assessing process safety cumulative risk is not a simple process due largely to the changing nature of safety critical barriers degradation data. The study result showed four main challenges faced by petroleum industries in Nigeria, in assessing process safety cumulative risk: 1) the study showed that 94% of the respondents agreed that there is limited accessibility to safety critical barriers degradation data (little automation). Also 2) 94% of the respondents accounted for poor knowledge of process safety cumulative risk is and agreed it to be of low rating. The result further showed that 3) 90% of the respondents demonstrated that there are no guidance and procedures in assessing process safety cumulative risk and finally 4) 92% of the respondents reported that there is no real-time risk visualization model/ tool. Addressing these issues and challenges by the petroleum industries in the study area, will lead to successful assessment of process safety cumulative risk, thereby reducing the risk of major accidents.
基金Strategic Priority Research Program of Chinese Academy of Sciences,Grant No.XDA28040000,XDA28120000Natural Science Foundation of Shandong Province,Grant No.ZR2021MF094+2 种基金Key R&D Plan of Shandong Province,Grant No.2020CXGC010804Central Leading Local Science and Technology Development Special Fund Project,Grant No.YDZX2021122Science&Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta,Grant No.2022SZX11。
文摘Due to the complex and changeable environment under water,the performance of traditional DOA estimation algorithms based on mathematical model,such as MUSIC,ESPRIT,etc.,degrades greatly or even some mistakes can be made because of the mismatch between algorithm model and actual environment model.In addition,the neural network has the ability of generalization and mapping,it can consider the noise,transmission channel inconsistency and other factors of the objective environment.Therefore,this paper utilizes Back Propagation(BP)neural network as the basic framework of underwater DOA estimation.Furthermore,in order to improve the performance of DOA estimation of BP neural network,the following three improvements are proposed.(1)Aiming at the problem that the weight and threshold of traditional BP neural network converge slowly and easily fall into the local optimal value in the iterative process,PSO-BP-NN based on optimized particle swarm optimization(PSO)algorithm is proposed.(2)The Higher-order cumulant of the received signal is utilized to establish the training model.(3)A BP neural network training method for arbitrary number of sources is proposed.Finally,the effectiveness of the proposed algorithm is proved by comparing with the state-of-the-art algorithms and MUSIC algorithm.
基金National Key R&D Program of China,Grant/Award Number:2018YFC1504901Science and technology program of Gansu Province,Grant/Award Numbers:21JR7RA738,21JR7RA739+1 种基金Science and Technology Development Project of China Railway Research Institute Co.Ltd,Grant/Award Number:2017‐KJ008‐Z008‐XBNatural Science Foundation of Gansu Province,Grant/Award Number:145RJZA068。
文摘To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas.