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Weak Graph Map Homotopy and Its Applications

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 235-252页

作者： Conglei zhang Yanying WANG Zhiguo zhang Yan zhao School of Mathematical Sciences Hebei Normal UniversityShijiazhuang 050024China Department of Basic Science Shanxi Agricultural UniversityJinzhang 030801ShanxiChina Center for Topology and Geometry based Technology School of Mathematical SciencesHebei Normal UniversityShijiazhuang 050024China School of Mathematical Sciences Hebei Normal UniversityTaiyuan 030031China School of Mathematics and Computer Science Shanxi Normal UniversityShijiazhuang 050024China School of Mathematics and Science Hebei GEO UniversityShijiazhuang 050031China

The authors introduce a notion of a weak graph map homotopy(they call it M-homotopy),discuss its properties and *** prove that the weak graph map homotopy equivalence between graphs coincides with the graph homotopy equivalence defined by Yau et al in *** difference between them is that the weak graph map homotopy transformation is defined in terms of maps,while the graph homotopy transformation is defined by means of combinatorial *** discuss its advantages over the graph homotopy *** its applications,they investigate the mapping class group of a graph and the 1-order M P-homotopy group of a pointed simple ***,they show that the 1-order M P-homotopy group of a pointed simple graph is invariant up to the weak graph map homotopy equivalence.

关键词： Weak graph map homotopy Trivial vertex Strong deformation retract Mapping class group MP-Homotopy group

Potential of arbuscular mycorrhizal fungi for soil health:A review

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Pedosphere 2024年第2期34卷 279-288页

作者： Junling zhang Ruotong zhao Xia LI Jiangzhou zhang College of Resources and Environmental Sciences National Academy of Agriculture Green DevelopmentKey Laboratory of Plant-Soil InteractionsMinistry of EducationChina Agricultural UniversityBeijing 100193China College of Agronomy and Life Science Shanxi Datong UniversityDatong 037009China College of Resources and Environment/International Magnesium Institute Fujian Agriculture and Forestry UniversityFuzhou 350002China

Soil health is an important component of“One Health”.Soils provide habitat to diverse and abundant *** microbial diversity and functions is essential for building healthy soils towards sustainable *** mycorrhizal fungi(AMF)form potentially symbiotic associations with approximately 80%of land plant species that are well recognized for carbon flux and nutrient *** addition to disentangling the signaling pathways and regulatory mechanisms between the two partners,recent advances in hyphosphere research highlight some emerging roles of AMF and associated microbes in the delivery of soil *** paper reviews the contribution of AMF to soil health in agroecosystems,with a major focus on recent progress in the contribution of hyphosphere microbiome to nutrient cycling,carbon sequestration,and soil *** hyphosphere microbiome and fungal stimulants open avenues for developing new fertilizer formulas to promote AMF *** practice,developing AMF-friendly management strategies will have long-term positive effects on sustainable agriculture aiming at simultaneously providing food security,increasing resource use efficiency,and maintaining environment integrity.

关键词： arbuscular mycorrhizal fungi-friendly management strategies carbon sequestration hyphosphere microbiome nutrient cycling soil aggregation soilfunctions

Sub-Homogeneous Peridynamic Model for Fracture and Failure Analysis of Roadway Surrounding Rock

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3167-3187页

作者： Shijun zhao Qing zhang Yusong Miao Weizhao zhang Xinbo zhao Wei Xu School of Science Qingdao University of TechnologyQingdao266520China College of Mechanics and Materials Hohai UniversityNanjing211100China Xibei Mining Co. Ltd.Shandong Energy GroupXi’an710018China

The surrounding rock of roadways exhibits intricate characteristics of discontinuity and *** address these complexities,this study employs non-local Peridynamics(PD)theory and reconstructs the kernel function to represent accurately the spatial decline of long-range ***,modifications to the traditional bondbased PD model are *** considering the micro-structure of coal-rock materials within a uniform discrete model,heterogeneity characterized by bond random pre-breaking is *** approach facilitates the proposal of a novel model capable of handling the random distribution characteristics of material heterogeneity,rendering the PD model suitable for analyzing the deformation and failure of heterogeneous layered coal-rock mass *** established numerical model and simulation method,termed the sub-homogeneous PD model,not only incorporates the support effect but also captures accurately the random heterogeneous micro-structure of roadway surrounding *** simulation results obtained using this model show good agreement with field measurements from the Fucun coal mine,effectively validating the model’s capability in accurately reproducing the deformation and failure mode of surrounding rock under bolt-supported(anchor cable).The proposed subhomogeneous PD model presents a valuable and effective simulation tool for studying the deformation and failure of roadway surrounding rock in coal mines,offering new insights and potential advancements.

关键词： Roadway surrounding rock peridynamics heterogeneous material fracture analysis numerical simulation

Precipitation and anthropogenic activities regulate the changes of NDVI in Zhegucuo Valley on the southern Tibetan Plateau

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Journal of Mountain Science 2024年第2期21卷 607-618页

作者： zhao Wanglin WANG Hengying zhang Huifang zhang Lin School of Ecology and Environment Tibet UniversityLhasa 850000China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100101China Southwest Survey and Planning Institute of National Forestry and Grassland Administration Kunming 650000China Monitoring Center for Ecological Environment of Xizang Autonomous Region Lhasa 850000China

Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may provide important guidance for local government policy and grassland *** two of the most reliable satellite NDVI products(MODIS NDVI and SPOT NDVI),we evaluated the dynamic of grasslands in the Zhegucuo valley on the southern Tibetan Plateau from 2000 to 2020,and analyzed its driving factors and relative influences of climate change and anthropogenic ***,the key indicators of climate change were assumed to be precipitation and *** main results were:(1)the grassland NDVI in Zhegucuo valley did not reflect a significant temporal change during the last 21 *** variation of precipitation during the early growing season(GSP)resembled that of NDVI,and the GSP was positively correlated with *** the pixel level,the partial correlation analysis showed that 37.79%of the pixels depicted a positive relationship between GSP and NDVI,while 11.32%of the pixels showed a negative relationship between temperature during the early growing season(GST)and NDVI.(2)In view of the spatial distribution,the areas mainly controlled by GSP were generally distributed in the southern part,while those affected by GST stood in the eastern part,mainly around the Zhegucuo lake where most population in Cuomei County settled down.(3)Decreasing NDVI trends were mainly occurred in alpine steppe at lower elevations rather than alpine meadow at higher elevations.(4)The residual trend(RESTREND)analysis further indicated that the anthropogenic activities played a more pivotal role in regulating the annual changes of NDVI rather than climate factors in this *** studies should pay more attention on climate extremes rather than the simple temporal ***,the influence of human activities on alpine grassland needs to be accessed and fully

关键词： Anthropogenic activities Climate change Precipitation Fencing Vegetation degradation

Promoted monolithic perovskite/organic tandem solar cells through elaborate manipulation of light transmission and carrier tunneling in interconnect junction

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Science China Chemistry 2024年第9期67卷 3131-3139页

作者： Rongbo Wang Jiawei zhang Juntao zhao Ya Wang Yi Ding Ying zhao Xiaodan zhang Guofu Hou Institute of Photoelectronic Thin Film Devices and Technology Renewable Energy Conversion and Storage CenterSolar Energy Conversion CenterNankai UniversityTianjin 300350China Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Tianjin 300350China Engineering Research Center of Thin Film Photoelectronic Technology of Ministry of Education Tianjin 300350China State Key Laboratory of Photovoltaic Materials and Solar Cells Tianjin 300350China

Monolithic perovskite/organic tandem solar cells(TSCs)have emerged as promising thin film solar *** is recognized that interconnect junction plays a pivotal role in tandem ***,wide bandgap Cs_(0.25)FA_(0.75)Pb(I_(0.6)Br_(0.4))_(3)perovskite top-cell and narrow bandgap PM6:Y6:PC_(61)BM ternary organic bottom-cell were integrated in this study with several kinds of thin metal interconnect layers,which provides feasibility to elaborately manipulate light transmission and carrier tunneling process in interconnect *** is confirmed that,in comparison with Au,employing an Ag interconnect layer elevates integrated transmittance of light in longer wavelength regions,mainly because of the alleviated screening effect with a lower free electron concentration,which offers sufficient light harvest for the ***,established energy barriers with moderate height afford convenient extraction and recombination for both holes and ***,the performance of TSCs is promoted ***,an innovative Ag/Au double interconnect layer is proposed accordingly,which can preserve exceptional conductivity and light transmission and further reduce barrier height,especially for hole tunneling,by optimizing the band alignment between the interconnect layer and ***,the monolithic perovskite/organic TSC with a striking efficiency of 23.26% is *** a word,this study can pave a general approach toward high-performance TSCs integration.

关键词： tandem solar cells band alignment perovskite organic solar cells interconnect junction

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Testing Linearity in Functional Partially Linear Models

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 875-886页

作者： Fan-rong zhao Bao-xue zhang School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Statistics Capital University of Economics and BusinessBeijing 100070China

For the functional partially linear models including flexible nonparametric part and functional linear part,the estimators of the nonlinear function and the slope function have been studied in existing *** to test the correlation between response and explanatory variables,however,still seems to be ***,a test procedure for testing the linearity in the functional partially linear models will be proposed in this paper.A test statistic is constructed based on the existing estimators of the nonlinear and the slope ***,we prove that the approximately asymptotic distribution of the proposed statistic is a chi-squared distribution under some regularity ***,some simulation studies and a real data application are presented to demonstrate the performance of the proposed test statistic.

关键词： asymptotic theory functional partially linear model Nadaraya-Watson estimate test statistic

Depositional Responses to the Mongol-Okhotsk Ocean Closure in the Central Area of the Great Xing’an Range: Insights into Thrust Faults and Foreland Basins

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Journal of Earth Science 2024年第3期35卷 797-811页

作者： Zheren zhao Shichao Li Lingyu zhang College of Earth Sciences Jilin UniversityChangchun 130061China Key Laboratory of Mineral Resources Evaluation in Northeast Asia Ministry of Natural ResourcesChangchun 130061China Department of Geosciences and Natural Resource Management University of CopenhagenCopenhagen 1350Denmark

The Mongol-Okhotsk Ocean,which has been closing gradually from the west to the east beginning since the Late Paleozoic,was an important part of the Central Asian Orogenic *** influenced the tectonic framework of Northeast Asia in the Mesozoic,especially the Late Mesozoic arc-basin system that is widely distributed in the Great Xing’an ***,the manner in which the Mongol-Okhotsk Ocean affected the sedimentary basin development remains poorly *** address this issue,we conducted U-Pb dating of detrital zircon deposited sedimentary basins of the central Great Xing’an *** examining the possible provenances of the detrital zircon and the structural controls of the basins,we found that a key sedimentary unit was deposited around Late Jurassic-Early *** provenance was a felsic source in a back-arc setting of an active continental *** findings also suggest the existence of a unified geodynamic setting that affected the coeval development of basins in the northern Great Xing’an Range and the Yanshan fold-thrust belt along the northern margin of North China *** research helps to better understand the complex tectonic processes which shaped the Northeast Asia during the Late Mesozoic.

关键词： Mongol-Okhotsk tectonic domain depositional responses Murui Formation zircon geochemistry tectonics.

P-symmetric Subharmonic Solutions for Nonlinear Hamiltonian Systems

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1388-1408页

作者： Duan Zhi zhang Zhi Hao zhao School of Mathematical Sciences Nankai UniversityTianjin 300071P.R.China

In this paper,we prove that for each positive k≡1 mod m there exists a P-symmetric kmτ-periodic solution xk for asymptotically linear mτ-periodic Hamiltonian systems,which are nonautonomous and endowed with a *** the P-symmetric Hamiltonian function is semi-positive,one can prove,under a new iteration inequality of the Maslov-type P-index,that xk_(1) and xk_(2) are geometrically distinct for k_(1)/k_(2)≥(2n+1)m+1;and xk_(1),xk_(2) are geometrically distinct for k_(1)/k_(2)≥m+1 provided xk_(1) is non-degenerate.

关键词： P-symmetric subharmonic Hamiltonian systems Maslov-type index theory iteration inequality asymptotically linear

Glacial-interglacial cycles recorded in clay minerals from the eastern Tibetan Plateau over the last 800 ka and their indications

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Science China Earth Sciences 2024年第7期67卷 2162-2177页

作者： Xiaoyan zhang Chunxia zhang Yan zhao Bin HU Zhengtang GUO Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Clay mineral proxies have been widely used to reconstruct changes in provenance and the ***,high-altitude clay mineral indications and long-term and orbital variations have not been fully ***,we present an800-ka clay-mineral record from a lacustrine sediment core(ZB13-C2)from the Zoige Basin on the eastern Tibetan Plateau(TP).X-ray diffraction and scanning electron microscopy were used to identify the clay mineral assemblages and their micromorphological characteristics of core *** results revealed that the clay minerals in core ZB13-C2 are mainly illite,with small amounts of chlorite,kaolinite,and smectite(including irregular mixed-layers of illite-smectite(I/S)and chloritesmectite(C/S)).The clay mineral assemblages and proxies exhibit three stages of change,which are mainly controlled by the Zoige watershed range under different climate *** watershed was limited to the southeastern region with altitudes ranging from~3500 to~4200 meters above sea level(m a.s.l.),and glacial-interglacial hydraulic erosion controlled the input of bedrock debris during 800-621 ka *** expanded to higher altitudes(~4200 to~4700 m a.s.l.)due to stronger seasonal freezethaw weathering without significant glacial-interglacial variations under a cooling and drying climate during 621-100 ka ***,it expanded to its highest altitudes of~4700 to~5200 m *** of the watershed after 100 ka BP,and hydraulic erosion increased obviously under a warm climate of the interstadial MIS 3 on the *** watershed underwent two major expansions under different climatic conditions at~621 ka and 100 ka BP,with the wet/dry alternation became strong at~621 ka *** results reveal that long-term temperature changes and the wet/dry alternation at high altitudes controlled the watershed range and degree of the physical erosion,and that the indications of clay minerals should be carefully clarified before they are used as climate indicators,especi

关键词： Quaternary Zoige Basin Lacustrine sediments Paleoenvironment Weathering