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Dependence of the IMF sector structure on the solar dipole tilt angle

中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： H.Luo G.X.Chen A.M.Du w.y.xu Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences

we statistically study the solar wind dependence of the magnetospheric activities during intense northward interplanetary magnetic fields(IMFs) events(Bz > 10 nT,last over 3 h).It was found that the energy coupling between solar wind and magnetosphere during intense northward IMFs was mainly controlled by solar wind velocity and IMF clock angle(θ).A northward IMF coupling function was derived based on the dimensional analysis and quantitative analysis of the solar wind parameters and the geomagnetic *** was shown that whenθ>～45°,the energy input increases obviously asθ*** importantly,it was also found that the relative importance between the viscous interaction and the IMF |By| effect in controlling the energy input into the magnetosphere during intense northward IMFs mainly depends on IMF clock *** viscous interaction will outweigh the IMF |By| effect in the northward IMF events with 0 ward IMF events withθ>～75°,the IMF \By\ effect may be more important than the viscous interaction.

关键词： Energy coupling Northward interplanetary magnetic field Viscous interaction IMF |By| effect

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Dependence of the IMF sector structure on the solar dipole t...

Conventional and micro scale finite element modeling for metal cutting process:A review

中国科学院地质与地球物理研究所2008学术年会

作者： A.M.Du,w.y.xu,and X.S.Feng 1 Institute of Geology and Geophysics,Chinese Academy of Sciences, Beijing,China. 2 State Key Laboratory for Space weather,Chinese Academy of Sciences,Beijing,China.

[1]The quasiperiodic variations of the interplanetary magnetic field(IMF) sector structure at the ACE satellite(L1) are investigated using power spectrum *** appears that the two-sector structure of the IMF dominates during the solar maximum, lasting 3 years from 2000 through 2003,and the four-sector structure dominates during the solar activity minimum.A possible explanation is introduced for this phenomenon in which the IMF sector structures vary with the tilt angle of the heliospheric current sheet (HCS) with respect to the solar rotation *** the solar activity maximum,the HCS is perpendicular to the ecliptic *** the spacecrafts at L1 point are expected to pass through the HCS only twice in one solar rotation,which gives rise to the observed two-sector structure of the *** the other hand,during the solar activity minimum,the HCS is nearly parallel to the ecliptic plane,and the polarity of IMF Bx changes several times in one solar rotation due to the wavy nature of the HCS, which may lead to the observed four-sector structure.

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Chinese Journal of Aeronautics 2024年第2期37卷 199-232页

作者： Le wANG Caixu yUE Xianli LIU Ming LI yongshi xu Steven y.LIANG Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George w.woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The metal cutting process is accompanied by complex stress field,strain field,temperature *** comprehensive effects of process parameters on chip morphology,cutting force,tool wear and residual stress are complex and *** element method(FEM)is considered as an effective method to predict process variables and reveal microscopic physical phenomena in the cutting ***,the finite element(FE)simulation is used to research the conventional and micro scale cutting process,and the differences in the establishment of process variable FE simulation models are distinguished,thereby improving the accuracy of FE *** reliability and effectiveness of FE simulation model largely depend on the accuracy of the simulation method,constitutive model,friction model,damage model in describing mesh element,the dynamic mechanical behavior of materials,the tool-chip-workpiece contact process and the chip formation *** this paper,the FE models of conventional and micro process variables are comprehensively and up-to-date reviewed for different materials and machining *** purpose is to establish a FE model that is more in line with the real cutting conditions,and to provide the possibility for optimizing the cutting process *** development direction of FE simulation of metal cutting process is discussed,which provides guidance for future cutting process modeling.

关键词： Conventional and micro scale Finite element simulation Metal cutting process Micro cutting Modeling

Optimal Coordination of Transportable Power Sources and Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 189-201页

作者： Zhao Shi yan xu Dunjian Xie Shiwei Xie Amer M.y.M.Ghias Nanyang Technological University Singapore the School of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108China

This paper proposes a new method for service restoration of distribution network with the support of transportable power sources(TPSs)and repair crews(RCs).Firstly,a coupling model of distribution networks and vehicle routing of TPSs and RCs is proposed,where the TPSs serve as emergency power supply sources,and the RCs are used to repair the faulted *** the uncertainty of traffic congestion,the probability distribution of the travel time spent on each road is derived based on the Nesterov user equilibrium model,and a two-stage stochastic program is formulated to determine the optimal routings of TPSs and *** efficiently solve the proposed stochastic mixed-integer linear program(MILP),a two-phase scenario reduction method is then developed to scale down the problem size,and an adaptive progressive hedging algorithm is used for an efficient *** effectiveness of the proposed methods and algorithms has been illustrated in a modified IEEE 33-bus system.

关键词： Service restoration distribution network traffic uncertainty transportable power source repair crew stochastic program

The Effect of Procrastination on Physical Exercise among College Students—The Chain Effect of Exercise Commitment and Action Control

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International Journal of Mental Health Promotion 2024年第8期26卷 611-622页

作者： Zhang w. xu M. Feng y. Mao Z. yan Z. Department of Physical Education Qufu Normal University Qufu 273165 China Department of Internal Medicine The Ohio State University Columbus 43210 OH United States Teaching Department of Common Courses Shandong University of Art & Design Jinan 250399 China School of Psychology Beijing Sport University Beijing 100084 China School of Physical Education Chongqing University of Posts and Telecommunications Chongqing 400065 China

Background: Exercise procrastination is prevalent among college students, causing decline in physical fitness. It is imperative to investigate the mechanism affecting college students’ physical activity behaviors. This study was aimed at investigating the effect of procrastination on college students’ physical exercise behavior, and the chain mediation effects of exercise commitment and action control (AC), to provide a theoretical basis for interventions targeting physical exercise behavior among college students. Methods: A questionnaire survey was conducted using convenience sampling. The General Procrastination Scale, Exercise Commitment Scale, Action Control Scale, and Physical Activity Rating Scale-3 questionnaires were used. Participants were 581 college students (age 19.27 ± 0.94 years; 243 males and 338 females). Statistical methods of regression analysis and structural equation modeling (SEM) were applied. Results: Procrastination, exercise commitment, and action control were found to be significant predictors of physical exercise behavior. Among these predictors, exercise commitment and action control showed full mediation effects in the relationship between procrastination and physical exercise behavior, and explained 25.48% and 30.77% of the total variance, respectively. The chain mediation effect of exercise commitment-action control was significant, accounting for 22.60% of the total variance, and the total indirect effect was 79.33%. Conclusion: Therefore, higher procrastination was associated with less participation in physical exercise behavior among college students. Improvements in exercise commitment and volitional decision-making ability for physical exercise behavior promoted physical exercise behavior, and increased exercise commitment promoted volitional decision-making ability among the students. The chain reaction effect of exercise commitment and action control also buffered the negative effects of procrastination on physical exercise beh

关键词： action control chain intermediary College student exercise behavior exercise commitment procrastination

Caudal hematopoietic tissue supports definitive erythrocytes via epoa and is dispensable for definitive neutrophils

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Journal of Genetics and Genomics 2024年第6期51卷 669-672页

作者： Zhujuan Huang yongtai xu Zhongkai Qiu yunyun Jiang Jiaye wu Qing Lin Sicong He Jianan y.Qu Jiahao Chen Jin xu Innovation Centre of Ministry of Education for Development and Diseases School of MedicineSouth China University of TechnologyGuangzhouGuangdong 510006China Department of Biology School of Life SciencesSouthern University of Science and TechnologyShenzhenGuangdong 518055China Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyKowloonHongkong 999077China

The blood system originates from hematopoietic stem cells(HSCs),capable of self-renewal and differentiation,generating diverse blood cell types(Eaves,2015;Lucas,2021).The concept of the hematopoietic niche was first proposed in 1978(Schofield,1978),which is crucial for maintaining hematopoietic *** following studies,particularly in mammals,have utilized targeted genetic manipulation to identify and define these niches.

关键词： hematopoietic manipulation utilized

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

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Earth and Planetary Physics 2024年第1期8卷 204-214页

作者： A.M.Jorgensen TianRan Sun y.Huang L.Li R.xu L.Dai Chi wang New Mexico Institute of Mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few *** work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch *** the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution *** this paper we explore the reconstruction using,two,three,and four *** show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray imaging SMILE

Inflammatory Factor IL1αInduces Aberrant Astrocyte Proliferation in Spinal Cord Injury Through the Grin2c/Ca^(2+)/CaMK2b Pathway

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Neuroscience Bulletin 2024年第4期40卷 421-438页

作者： yu Xia Lu Ding Changlin Zhang Qi xu Ming Shi Tianshun Gao Feng-Quan Zhou David y.B.Deng Scientific Research Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Department of Gynecology The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Pelvic Floor Disorders Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Big Data Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Sir Run Run Shaw Hospital Zhejiang University School of MedicineHangzhou310016China Orthopaedic and Neurological Repair Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China

Spinal cord injury(SCI)is one of the most devastating traumas,and the aberrant proliferation of astrocytes usually causes neurological ***,the mechanism underlying astrocyte over-proliferation after SCI is ***2c(glutamate ionotropic receptor type 2c)plays an essential role in cell *** bioinformatic analysis indicated that Grin2c and Ca^(2+)transport functions were inhibited in astrocytes after *** of Grin2c stimulated astrocyte proliferation by inhibiting the Ca^(2+)/calmodulin-dependent protein kinase 2b(CaMK2b)pathway in *** screening different inflammatory factors,interleukin 1α(IL1α)was further found to inhibit Grin2c/Ca^(2+)/CaMK2b and enhance astrocyte proliferation in an oxidative damage *** of IL1αusing neutralizing antibody resulted in increased Grin2c expression and the inhibition of astrocyte proliferation ***,this study suggests that IL1αpromotes astrocyte proliferation by suppressing the Grin2c/Ca^(2+)/CaMK2b pathway after SCI,revealing a novel pathological mechanism of astrocyte proliferation,and may provide potential targets for SCI repair.

关键词： IL1α Grin2c Astrocyte Spinal cord injury

Evolutionary history shapes variation of wood density of tree species across the world

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Plant Diversity 2024年第3期46卷 283-293页

作者： Fangbing Li Hong Qian Jordi Sardans Dzhamal y.Amishev Zixuan wang Changyue Zhang Tonggui wu Xiaoniu xu Xiao Tao Xingzhao Huang Anhui Province Key Laboratory of Forest Resources and Silviculture Anhui Agricultural UniversityHefei 230036China State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL 62703USA CREAF Cerdanyola del VallesBarcelona 08193Spain Global Ecology Unit CREAF-CSIC-UAB CSICBellaterraBarcelona 08193Spain Key Laboratory of Ecosystem Carbon Source and Sink China Meteorological Administration(ECSS-CMA)School of Applied MeteorologyNanjing University of Information Science&Technology219 Ningliu RoadNanjing 210044China Department of Natural Resources Management Lakehead UniversityThunder BayOntario P7B 5E1Canada School of Forestry&Landscape of Architecture Anhui Agricultural UniversityHefei 230036China Research Institute of Subtropical Forestry Chinese Academy of ForestryHangzhou 311400China

The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been *** a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree *** assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density *** found that wood density displayed a significant phylogenetic *** density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into *** angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for *** study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density.

关键词： wood density Phylogeny Angiosperms Gymnosperms Climate factors Biophysical parameters