Sensitive materials mainly composed of ZnO and their multi-functional properties were investigated. The temperature extent of linear resistance, non-linear deviation and endurance ability of surge energy were further ...Sensitive materials mainly composed of ZnO and their multi-functional properties were investigated. The temperature extent of linear resistance, non-linear deviation and endurance ability of surge energy were further discussed. The effect of Mg^2+, AI^3+ and Si^4+, which could be solid solutioned in ZnO grain and the function of Y^3+ ion segregated out in grain boundary were studied as well. The function of Ti was analyzed emphatically.展开更多
Objective: To observe and assess the efficacy enhancing and toxicity attenuating effect of Nuzhen Yangyin Granule (NYG) to the anti-parkinsonism (paralysis agitans) therapy with medopa and ar-tane. Methods: Adopting t...Objective: To observe and assess the efficacy enhancing and toxicity attenuating effect of Nuzhen Yangyin Granule (NYG) to the anti-parkinsonism (paralysis agitans) therapy with medopa and ar-tane. Methods: Adopting the randomized double-blinded method, the effect of adding NYG to 30 patients with Parkinsonism in the treated group,展开更多
Objective To compare the difference in the efficacy on spasmodic torticollis between matrix needling technique combined with puncturing"Wuxin points"and the local injection of botox type A.Methods Forty-two ...Objective To compare the difference in the efficacy on spasmodic torticollis between matrix needling technique combined with puncturing"Wuxin points"and the local injection of botox type A.Methods Forty-two cases were randomized into an acupuncture group and a展开更多
Based on the data of drilling,logging,experiment and gas testing in the Nanchuan area,southeastern Sichuan Basin,the hydrocarbon generation potential,gas genesis,occurrence state,migration,preservation conditions,pore...Based on the data of drilling,logging,experiment and gas testing in the Nanchuan area,southeastern Sichuan Basin,the hydrocarbon generation potential,gas genesis,occurrence state,migration,preservation conditions,pore and fracture features and accumulation evolution of the first member of Permian Maokou Formation(Mao 1 Member)are systematically studied,and the main controlling factors of unconventional gas enrichment and high production in marlstone assemblage of Mao 1 Member are discussed.(1)The enrichment and high yield of unconventional natural gas in the Mao 1 Member are controlled by three factors:carbon-rich fabric controlling hydrocarbon generation potential,good preservation controlling enrichment,and natural fracture controlling production.(2)The carbonate rocks of Mao 1 Member with carbon rich fabric have significant gas potential,exhibiting characteristics of self-generation and self-storage,which lays the material foundation for natural gas accumulation.(3)The occurrence state of natural gas is mainly free gas,which is prone to lateral migration,and good storage conditions are the key to natural gas enrichment.Positive structure is more conducive to natural gas accumulation,and a good compartment is created jointly by the self-sealing property of the Mao 1 Member and its top and bottom sealing property in monoclinal area,which is favorable for gas accumulation by retention.(4)Natural fractures are the main reservoir space and flow channel,and the more developed natural fractures are,the more conducive to the formation of high-quality porous-fractured reservoirs and the accumulation of natural gas,which is the core of controlling production.(5)The accumulation model of unconventional natural gas is proposed as“self-generation and self-storage,preservation controlling richness,and fractures controlling production”.(6)Identifying fracture development areas with good preservation conditions is the key to successful exploration,and implementing horizontal well staged acidizing and fracturing is an important means to increase production and efficiency.The study results are of referential significance for further understanding the natural gas enrichment in the Mao 1 Member and guiding the efficient exploration and development of new types of unconventional natural gas.展开更多
Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.T...Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.展开更多
One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific object...One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.展开更多
Aiming at the problems of difficulty in balancing construction efficiency and quality,as well as the high safety risks of working at heights during the construction of main piers for highway bridges,this study takes a...Aiming at the problems of difficulty in balancing construction efficiency and quality,as well as the high safety risks of working at heights during the construction of main piers for highway bridges,this study takes a specific bridge project as an example to introduce the technology of hydraulically sliding formwork for the construction of main piers of highway bridges.An in-depth analysis of the project’s construction process found that this technology can effectively improve construction efficiency,ensure the quality of concrete pouring,and significantly reduce the potential safety hazards of working at heights.It provides a reliable technical solution for constructing the main piers of highway bridges and has important reference significance for similar projects.展开更多
Frankfurt am Main,7 April 2o25.Textile interior design at its best is an inte-gral part of Heimtextil,the most inftuentiailand giobai platform for home and contracttextiles as well as textile design.PatriciaUrquiola e...Frankfurt am Main,7 April 2o25.Textile interior design at its best is an inte-gral part of Heimtextil,the most inftuentiailand giobai platform for home and contracttextiles as well as textile design.PatriciaUrquiola expressed this spectacularly inJaruary in Frankfuirt with her installation'among-us'.展开更多
I.What are topic sentences in a passage?A topic sentence is the main idea of a paragraph.It tells readers what the paragraph will talk about.Usually,the topic sentence is the first sentence of a paragraph,but sometime...I.What are topic sentences in a passage?A topic sentence is the main idea of a paragraph.It tells readers what the paragraph will talk about.Usually,the topic sentence is the first sentence of a paragraph,but sometimes it can come in the middle or at the end.A good topic sentence helps readers understand the writer's purpose quickly.展开更多
Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resol...Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resolution and deep tissue penetration.However,the inherent challenges associated with photoacoustic signal excitation,propagation and detection often result in suboptimal image quality.To overcome these limitations,researchers have developed various advanced algorithms that span the entire image reconstruction pipeline.This review paper aims to present a detailed analysis of the latest advancements in PACT algorithms and synthesize these algorithms into a coherent framework.We provide tripartite analysis—from signal processing to reconstruction solution to image processing,covering a spectrum of techniques.The principles and methodologies,as well as their applicability and limitations,are thoroughly discussed.The primary objective of this study is to provide a thorough review of advanced algorithms applicable to PACT,offering both theoretical foundations and practical guidance for enhancing the imaging effect of PACT.展开更多
The quantitative trait loci(QTL)-by-environment(Q × E) interaction effect is hard to detect because there are no effective ways to control the genomic background. In this study, we propose a linear mixed model th...The quantitative trait loci(QTL)-by-environment(Q × E) interaction effect is hard to detect because there are no effective ways to control the genomic background. In this study, we propose a linear mixed model that simultaneously analyzes data from multiple environments to detect Q × E interactions. This model incorporates two different kinship matrices derived from the genome-wide markers to control both main and interaction polygenic background effects. Simulation studies demonstrate that our approach is more powerful than the meta-analysis and inclusive composite interval mapping methods. We further analyze four agronomic traits of rice across four environments. A main effect QTL is identified for 1000-grain weight(KGW), while no QTL are found for tiller number. Additionally, a large QTL with a significant Q × E interaction is detected on chromosome 7 affecting grain number, yield, and KGW. This region harbors two important genes, PROG1 and Ghd7. Furthermore, we apply our mixed model to analyze lodging in barley across six environments. The six regions exhibiting Q × E interaction effects identified by our approach overlap with the SNPs previously identified using EM and MCMC-based Bayesian methods, further validating the robustness of our approach. Both simulation studies and empirical data analyses show that our method outperforms all other methods compared.展开更多
The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its impor...The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its importance,there has been a relative paucity of research focusing on the spatiotemporal variations of snow cover,key controlling factors,and variability within HMA sub-basins.This study aims to address this gap by extracting snow cover percentage(SCP)and snow cover days(SCD)data from MOD10A2 snow products,integrating these with precipitation(P)and temperature(T)data from ERA5.Our objective is to analyze the spatiotemporal distribution characteristics of snow cover and to use path analysis to elucidate the key climatic factors and spatial differences influencing snow cover changes.The findings indicate that,on a temporal scale,the overall SCP in HMA exhibited a declining trend from 2001 to 2021.Interannual variations in SCP across HMA sub-basins revealed a decreasing trend in the Pamir(PAM),Western Tibetan Plateau(WTS),Eastern Tibetan Plateau(ETS),Western Kunlun(WKL),Qilian Shan(QLS),and Himalaya(HDS)regions,while an increasing trend was observed in other areas.Spatially,22.97%of the HMA regions experienced an increase in SCD,primarily in the Western Himalaya(WHL),Central Himalaya(CHL),and Southeastern Xizang(SET)regions.Conversely,28.08%of the HMA regions showed a decrease in SCD,predominantly in the Eastern Himalaya(EHL),HDS,and WTS regions.Temperature(T)emerged as the primary influencing factor of SCD change in most HMA sub-basins.However,in the Eastern Kunlun(EKL)and WHL sub-basins,precipitation(P)was identified as the main driver of SCD change,affecting all elevation zones in these regions.Additionally,other climatic conditions can also impact snow cover beyond the primary controlling factor.展开更多
In the paper,copepod universal formulas are applied to construct a copepod individual-based model(IBM),and a genetic algorithm(GA)is incorporated in the formulas with genes as species parameters.The IBM initially cons...In the paper,copepod universal formulas are applied to construct a copepod individual-based model(IBM),and a genetic algorithm(GA)is incorporated in the formulas with genes as species parameters.The IBM initially constructs the individuals with all possible genes similar to the original state of natural selection.Climate-averaged temperature and chlorophyll a(Chl a)time series at the surface layer of fixed points in the Georges Bank(GB)and the Gulf of Maine(GOM)are taken as the model environment.The IBM has been running for 50 a in the environment without inter-annual change.The IBM results indicate that some of the life history traits of the top ten abundant species output by the IBM in the GB and the GOM are consistent with the real species Calanus finmarchicus,Pseudocalanus spp.,Centropages typicus,and Centropages hamatus in terms of reproduction strategy,time to reach the maximum abundance,water temperature preference,and adult body mass.The study of the top ten abundant species with multidimensional scaling(MDS)and clustering analysis(CA)methods indicates that reproduction strategy is the basis for grouping.For the species taking the broadcasting strategy,both GB and GOM environments tend to choose smallbodied species with cold-water preference,such as Pseudocalanus spp.;for the species taking the egg-carrying strategies,the GB environment selects large-bodied species with cold-water preference,such as C.finmarchicus,while the GOM environment selects medium-bodied species with warm-water preference,such as Centropages spp.(C.typicus and C.hamatus).After gene mutation is added to the IBM,the model result gets simple,which needs to be further improved.The significance of the paper lies in systematically studying the impact of GB and GOM environments on the evolutionary life history traits of copepods for the first time.展开更多
Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee th...Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this study.The proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical equipment.Then,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed method.The results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure probability.The seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility curve.Furthermore,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.展开更多
This study generalizes the classical Taylor-Sedov framework to analyze finitesource spherical blast waves propagating through both uniform and power-law density media. Previous analyses have predominantly focused on t...This study generalizes the classical Taylor-Sedov framework to analyze finitesource spherical blast waves propagating through both uniform and power-law density media. Previous analyses have predominantly focused on the effects of varying initial conditions on blast dynamics. In contrast, this study investigates the primary shock wave evolution within different ambient gases, demonstrating the critical dependence on the initial density ratio between the blast sphere and the ambient medium, as well as the ambient density profile. We derive new scaling laws based on the density ratio, which accurately predict the dimensionless main shock distance. Furthermore, we systematically examine, for the first time, the conditions for uniform volume expansion, uniform surface area growth, and uniform shock wave propagation in power-law density media, revealing a key scaling relation associated with the power-law exponent. Numerical simulations validate these novel theoretical predictions, demonstrating excellent agreement with the normalized solutions. These findings provide new insights into blast wave dynamics in inhomogeneous media and have implications for astrophysical and laboratory plasma environments.展开更多
This study demonstrates simultaneous enhancement of magnetic and mechanical properties in NdFeB magnets through Ti addition.The coercivity increases by 1.1 kOe without compromising remanence,while bending strength imp...This study demonstrates simultaneous enhancement of magnetic and mechanical properties in NdFeB magnets through Ti addition.The coercivity increases by 1.1 kOe without compromising remanence,while bending strength improves by 159.05%.Analytical results reveal that Ti predominantly combines with free B atoms to form TiB_(2)phases,which reduce the brittleness of grain boundary(GB)phase and impede dislocation motion.The superposition of stress fields around dislocations generates reactive forces that counteract external loads,thereby enhancing GB strength.Concurrently,B depletion in GB phases induces amorphous transformation,further enhancing boundary strength.A minor fraction of Ti incorporates into the main phase,enhancing covalent bond strength and forming a reinforced main phase.Additionally,Ti addition promotes grain refinement and increases GB density,significantly improving bending strength.The synergistic effects of heterogeneous phase formation,amorphous transformation,main phase reinforcement,and grain refinement collectively enable coordinated strengthening between the main phase and GBs.This multi-mechanism approach provides novel insights for mechanical property optimization in Nd FeB magnets.展开更多
基金National Natural Science Foundation of China!(No. 59972011).
文摘Sensitive materials mainly composed of ZnO and their multi-functional properties were investigated. The temperature extent of linear resistance, non-linear deviation and endurance ability of surge energy were further discussed. The effect of Mg^2+, AI^3+ and Si^4+, which could be solid solutioned in ZnO grain and the function of Y^3+ ion segregated out in grain boundary were studied as well. The function of Ti was analyzed emphatically.
文摘Objective: To observe and assess the efficacy enhancing and toxicity attenuating effect of Nuzhen Yangyin Granule (NYG) to the anti-parkinsonism (paralysis agitans) therapy with medopa and ar-tane. Methods: Adopting the randomized double-blinded method, the effect of adding NYG to 30 patients with Parkinsonism in the treated group,
文摘Objective To compare the difference in the efficacy on spasmodic torticollis between matrix needling technique combined with puncturing"Wuxin points"and the local injection of botox type A.Methods Forty-two cases were randomized into an acupuncture group and a
基金Supported by the National Science and Technology Major Project of China(2016ZX05061)Sinopec Science and Technology Department Project(P21042-4,P25030)。
文摘Based on the data of drilling,logging,experiment and gas testing in the Nanchuan area,southeastern Sichuan Basin,the hydrocarbon generation potential,gas genesis,occurrence state,migration,preservation conditions,pore and fracture features and accumulation evolution of the first member of Permian Maokou Formation(Mao 1 Member)are systematically studied,and the main controlling factors of unconventional gas enrichment and high production in marlstone assemblage of Mao 1 Member are discussed.(1)The enrichment and high yield of unconventional natural gas in the Mao 1 Member are controlled by three factors:carbon-rich fabric controlling hydrocarbon generation potential,good preservation controlling enrichment,and natural fracture controlling production.(2)The carbonate rocks of Mao 1 Member with carbon rich fabric have significant gas potential,exhibiting characteristics of self-generation and self-storage,which lays the material foundation for natural gas accumulation.(3)The occurrence state of natural gas is mainly free gas,which is prone to lateral migration,and good storage conditions are the key to natural gas enrichment.Positive structure is more conducive to natural gas accumulation,and a good compartment is created jointly by the self-sealing property of the Mao 1 Member and its top and bottom sealing property in monoclinal area,which is favorable for gas accumulation by retention.(4)Natural fractures are the main reservoir space and flow channel,and the more developed natural fractures are,the more conducive to the formation of high-quality porous-fractured reservoirs and the accumulation of natural gas,which is the core of controlling production.(5)The accumulation model of unconventional natural gas is proposed as“self-generation and self-storage,preservation controlling richness,and fractures controlling production”.(6)Identifying fracture development areas with good preservation conditions is the key to successful exploration,and implementing horizontal well staged acidizing and fracturing is an important means to increase production and efficiency.The study results are of referential significance for further understanding the natural gas enrichment in the Mao 1 Member and guiding the efficient exploration and development of new types of unconventional natural gas.
基金supported by the National Key R&D Program of China(2022YFF0504400)the National Natural Science Foundation of China(42188101,42274195,42174193)+2 种基金the International Partnership Program Of Chinese Academy of Sciences(Grant No.183311KYSB20200003)the USTC Research Funds of the Double First-Class Initiative(YD2080002013)the Joint Open Fund of Mengcheng National Geophysical Observatory(MENGO-202408).
文摘Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.
基金Supported by the National Natural Science Foundation of China(42474239,41204128)China National Space Administration(Pre-research project on Civil Aerospace Technologies No.D010301)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA17010303)。
文摘One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.
文摘Aiming at the problems of difficulty in balancing construction efficiency and quality,as well as the high safety risks of working at heights during the construction of main piers for highway bridges,this study takes a specific bridge project as an example to introduce the technology of hydraulically sliding formwork for the construction of main piers of highway bridges.An in-depth analysis of the project’s construction process found that this technology can effectively improve construction efficiency,ensure the quality of concrete pouring,and significantly reduce the potential safety hazards of working at heights.It provides a reliable technical solution for constructing the main piers of highway bridges and has important reference significance for similar projects.
文摘Frankfurt am Main,7 April 2o25.Textile interior design at its best is an inte-gral part of Heimtextil,the most inftuentiailand giobai platform for home and contracttextiles as well as textile design.PatriciaUrquiola expressed this spectacularly inJaruary in Frankfuirt with her installation'among-us'.
文摘I.What are topic sentences in a passage?A topic sentence is the main idea of a paragraph.It tells readers what the paragraph will talk about.Usually,the topic sentence is the first sentence of a paragraph,but sometimes it can come in the middle or at the end.A good topic sentence helps readers understand the writer's purpose quickly.
基金supported by Beijing Natural Science Foundation(7232146)National Natural Science Foundation of China(NSFC)Grant(62475277,62105355,82122034,82327805,81927807,62275062)+4 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0930000)Shenzhen Science and Technology Innovation Grant(JCYJ20220531100409023,JCYJ20210324101403010,JCYJ20220818101403008)Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments Grant(2021-SGTTXM005)Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund,YDZX2023115)Taishan Scholar Special Funding Project of Shandong Province.
文摘Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resolution and deep tissue penetration.However,the inherent challenges associated with photoacoustic signal excitation,propagation and detection often result in suboptimal image quality.To overcome these limitations,researchers have developed various advanced algorithms that span the entire image reconstruction pipeline.This review paper aims to present a detailed analysis of the latest advancements in PACT algorithms and synthesize these algorithms into a coherent framework.We provide tripartite analysis—from signal processing to reconstruction solution to image processing,covering a spectrum of techniques.The principles and methodologies,as well as their applicability and limitations,are thoroughly discussed.The primary objective of this study is to provide a thorough review of advanced algorithms applicable to PACT,offering both theoretical foundations and practical guidance for enhancing the imaging effect of PACT.
基金supported by the National Key Research and Development Programs of China(2024YFF1000100 and 2021YFD1301102)the National Natural Science Foundation of China (32172702)+3 种基金the State Key Laboratory of Animal Biotech Breeding (XQSWYZQZ-KFYX-4)Zaozhuang Elite Industrial Innovation ProgramAgricultural Science and Technology Innovation Program (ASTIP-IAS-TS-6)supported by the United States National Science Foundation (NSF) Collaborative Research Grant (DBI-1458515)
文摘The quantitative trait loci(QTL)-by-environment(Q × E) interaction effect is hard to detect because there are no effective ways to control the genomic background. In this study, we propose a linear mixed model that simultaneously analyzes data from multiple environments to detect Q × E interactions. This model incorporates two different kinship matrices derived from the genome-wide markers to control both main and interaction polygenic background effects. Simulation studies demonstrate that our approach is more powerful than the meta-analysis and inclusive composite interval mapping methods. We further analyze four agronomic traits of rice across four environments. A main effect QTL is identified for 1000-grain weight(KGW), while no QTL are found for tiller number. Additionally, a large QTL with a significant Q × E interaction is detected on chromosome 7 affecting grain number, yield, and KGW. This region harbors two important genes, PROG1 and Ghd7. Furthermore, we apply our mixed model to analyze lodging in barley across six environments. The six regions exhibiting Q × E interaction effects identified by our approach overlap with the SNPs previously identified using EM and MCMC-based Bayesian methods, further validating the robustness of our approach. Both simulation studies and empirical data analyses show that our method outperforms all other methods compared.
基金supported by Tianchi talent project(Granted No.51052401507)。
文摘The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its importance,there has been a relative paucity of research focusing on the spatiotemporal variations of snow cover,key controlling factors,and variability within HMA sub-basins.This study aims to address this gap by extracting snow cover percentage(SCP)and snow cover days(SCD)data from MOD10A2 snow products,integrating these with precipitation(P)and temperature(T)data from ERA5.Our objective is to analyze the spatiotemporal distribution characteristics of snow cover and to use path analysis to elucidate the key climatic factors and spatial differences influencing snow cover changes.The findings indicate that,on a temporal scale,the overall SCP in HMA exhibited a declining trend from 2001 to 2021.Interannual variations in SCP across HMA sub-basins revealed a decreasing trend in the Pamir(PAM),Western Tibetan Plateau(WTS),Eastern Tibetan Plateau(ETS),Western Kunlun(WKL),Qilian Shan(QLS),and Himalaya(HDS)regions,while an increasing trend was observed in other areas.Spatially,22.97%of the HMA regions experienced an increase in SCD,primarily in the Western Himalaya(WHL),Central Himalaya(CHL),and Southeastern Xizang(SET)regions.Conversely,28.08%of the HMA regions showed a decrease in SCD,predominantly in the Eastern Himalaya(EHL),HDS,and WTS regions.Temperature(T)emerged as the primary influencing factor of SCD change in most HMA sub-basins.However,in the Eastern Kunlun(EKL)and WHL sub-basins,precipitation(P)was identified as the main driver of SCD change,affecting all elevation zones in these regions.Additionally,other climatic conditions can also impact snow cover beyond the primary controlling factor.
基金The National Natural Science Foundation of China Project under contract No.42206150the Technology Development Program of Shanghai Ocean University under contract No.A2-2006-20-200207.
文摘In the paper,copepod universal formulas are applied to construct a copepod individual-based model(IBM),and a genetic algorithm(GA)is incorporated in the formulas with genes as species parameters.The IBM initially constructs the individuals with all possible genes similar to the original state of natural selection.Climate-averaged temperature and chlorophyll a(Chl a)time series at the surface layer of fixed points in the Georges Bank(GB)and the Gulf of Maine(GOM)are taken as the model environment.The IBM has been running for 50 a in the environment without inter-annual change.The IBM results indicate that some of the life history traits of the top ten abundant species output by the IBM in the GB and the GOM are consistent with the real species Calanus finmarchicus,Pseudocalanus spp.,Centropages typicus,and Centropages hamatus in terms of reproduction strategy,time to reach the maximum abundance,water temperature preference,and adult body mass.The study of the top ten abundant species with multidimensional scaling(MDS)and clustering analysis(CA)methods indicates that reproduction strategy is the basis for grouping.For the species taking the broadcasting strategy,both GB and GOM environments tend to choose smallbodied species with cold-water preference,such as Pseudocalanus spp.;for the species taking the egg-carrying strategies,the GB environment selects large-bodied species with cold-water preference,such as C.finmarchicus,while the GOM environment selects medium-bodied species with warm-water preference,such as Centropages spp.(C.typicus and C.hamatus).After gene mutation is added to the IBM,the model result gets simple,which needs to be further improved.The significance of the paper lies in systematically studying the impact of GB and GOM environments on the evolutionary life history traits of copepods for the first time.
基金National Key R&D Program of China under Grant Nos.2018YFC1504504 and 2018YFC0809404。
文摘Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this study.The proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical equipment.Then,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed method.The results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure probability.The seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility curve.Furthermore,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.
基金supported by the National Natural Science Foundation of China(Nos.12422208,12432011,12421002,and 12372220)。
文摘This study generalizes the classical Taylor-Sedov framework to analyze finitesource spherical blast waves propagating through both uniform and power-law density media. Previous analyses have predominantly focused on the effects of varying initial conditions on blast dynamics. In contrast, this study investigates the primary shock wave evolution within different ambient gases, demonstrating the critical dependence on the initial density ratio between the blast sphere and the ambient medium, as well as the ambient density profile. We derive new scaling laws based on the density ratio, which accurately predict the dimensionless main shock distance. Furthermore, we systematically examine, for the first time, the conditions for uniform volume expansion, uniform surface area growth, and uniform shock wave propagation in power-law density media, revealing a key scaling relation associated with the power-law exponent. Numerical simulations validate these novel theoretical predictions, demonstrating excellent agreement with the normalized solutions. These findings provide new insights into blast wave dynamics in inhomogeneous media and have implications for astrophysical and laboratory plasma environments.
基金financially supported by the National Natural Science Foundation of China(No.52361033)National Key Research and Development Program(No.2022YFB3505400)+6 种基金Ministry of Industry and Information Technology Heavy Rare Earth Special use of Sintered NdFeB Project(No.TC220H06J)Academic and Technical Leaders in Major Disciplines in Jiangxi Province(No.20225BCJ23007)Jiangxi Natural Science Foundation Youth Fund(No.20232BAB214011)the Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)Research Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(No.E255J001)Science and Technology Major Project of Ganzhou(No.202101064871)Program for Excellent Young Talents(No.JXUSTQJYC2024003)
文摘This study demonstrates simultaneous enhancement of magnetic and mechanical properties in NdFeB magnets through Ti addition.The coercivity increases by 1.1 kOe without compromising remanence,while bending strength improves by 159.05%.Analytical results reveal that Ti predominantly combines with free B atoms to form TiB_(2)phases,which reduce the brittleness of grain boundary(GB)phase and impede dislocation motion.The superposition of stress fields around dislocations generates reactive forces that counteract external loads,thereby enhancing GB strength.Concurrently,B depletion in GB phases induces amorphous transformation,further enhancing boundary strength.A minor fraction of Ti incorporates into the main phase,enhancing covalent bond strength and forming a reinforced main phase.Additionally,Ti addition promotes grain refinement and increases GB density,significantly improving bending strength.The synergistic effects of heterogeneous phase formation,amorphous transformation,main phase reinforcement,and grain refinement collectively enable coordinated strengthening between the main phase and GBs.This multi-mechanism approach provides novel insights for mechanical property optimization in Nd FeB magnets.
