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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

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

Three positive charge nonapoptotic-induced photosensitizer with excellent water solubility for tumor therapy

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Chinese Chemical Letters 2024年第8期35卷 205-210页

作者： Zhe Li ping-zhao Liang Li Xu Fei-Yu Yang Tian-Bing Ren Lin Yuan Xia Yin Xiao-Bing zhang State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China

Photodynamic therapy(PDT)has emerged as a significant cancer therapy ***,cation-based organic small molecule aggregation-induced emission(AIE)photosensitizers(PSs)attract the wide atten-tion of many scientists,due to improved reactive oxygen species(ROS)production after ***,such PSs tend to localize only the mitochondria,limiting the death way of tumor cells(usu-ally apoptosis)during PDT process,which may affect the therapeutic effect under some ***,we designed a novel water-soluble three positive charge PS,TPAN-18F,which could be distributed uniformly in cell cytoplasm and had distribution in different sub-organelles(mitochondria,endoplasmic reticulum,lysosome).The experimental results showed that TPAN-18F-based PDT process can not only disrupt mitochondrial functions(reducing ATP production and destroying mitochondrial membrane po-tential),but also elevate the intracellular lipid peroxides(LPOs)level,which evoke the non-apoptotic death manner of tumor ***,in vivo studies showed that TPAN-18F-based PDT could effectively inhibit tumor ***,we believe that the construction of TPAN-18F is suggestive for tumor non-apoptotic therapy.

关键词： Water-soluble Three positive charge Photosensitizer Nonapoptotic Tumor therapy

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

The First Ground-based White Light Lunar Polarization Imaging:A New Kind of FeO Observation on the Near Side of the Moon

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Research in Astronomy and Astrophysics 2024年第6期24卷 1-6页

作者： Wei-Nan Wang Jin-Song ping Ming-Yuan Wang Wen-zhao zhang Han-Lin Ye Xing-Wei Han Song-Feng Kou Changchun Observatory National Astronomical ObservatoriesChinese Academy of SciencesChangchun 130117China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 101408China Astronomy Department Beijing Normal UniversityBeijing 100875China International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Nanjing Institute of Astronomical Optics and Technology Chinese Academy of SciencesNanjing 210042China

Lunar optical polarization is a fascinating phenomenon that occurs when sunlight reflects off the surface of the Moon and becomes *** study employs a novel split-focus plane polarimetric camera to conduct the initial white light polarimetric observations on the near side of the *** obtained the linear degree of polarization(DOP)parameters of white light by observation from the eastern and western hemispheres of the *** findings indicate that the white light polarization is lower in the lunar highland than in the lunar maria *** the analysis of lunar soil samples,we noticed and determined that the DOP parameters of white light demonstrate high consistency with iron oxide on the *** study may serve as a new diagnostic tool for the Moon.

关键词： techniques:photometric polarization methods:observational Moon

Amorphous Sb/C composite with isotropic expansion property as an ultra-stable and high-rate anode for lithium-ion batteries

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Rare Metals 2024年第5期43卷 2039-2052页

作者： Ze-Zhou Yang Cheng-Yi zhang Yu-Qing Ou Zhi-Kang Su Yan zhao Heng-Jiang Cong Xin-ping Ai Jiang-Feng Qian Hubei Key Laboratory of Electrochemical Power Sources College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072China Institute of Technological Sciences Wuhan UniversityWuhan 430072China

Antimony(Sb)is an intriguing anode material for Li-ion batteries(LIBs)owing to its high theoretical capacity of 660 m Ah·g^(-1)and appropriate working potential of~0.8 V(***^(+)/Li).However,just like all alloying materials,the Sb anode suffers from huge volume expansion(230%)during repeated insertion/extraction of Li+ions,resulting in structural deterioration and rapid capacity *** this work,a novel amorphous Sb/C composite with atomically dispersed Sb particles in carbon matrix is prepared via a straightforward high-energy ball milling *** intimate intermixing of amorphous Sb with C provides homogeneous element distribution and isotropic volume expansion during cycling,resulting in persistent structural ***,the disordered structure of amorphous material shortens the diffusion distance of lithium ions/electrons,promoting fast reaction kinetics and rate *** from the aforementioned effects,the amorphous Sb/C exhibits a high reversible capacity of537.4 m Ah·g^(-1)at 0.1 A·g^(-1)and retains 201.0 m Ah·g^(-1)at an ultrahigh current rate of 10.0 A·g^(-1).Even after 1500deep cycles at 2.0 A·g^(-1),the amorphous Sb/C electrode still maintains 86.3%of its initial capacity,which outperforms all existing Sb-based anodes reported so *** analysis further reveals a greatly reduced volume variation of merely 34.6%for the amorphous Sb/C electrode,much lower than that of 223.1%for crystalline Sb *** study presents a new approach to stabilizing Sb-based alloy anodes and contributes to the construction of high-performance amorphous anode materials for LIBs,enabling advanced energy storage.

关键词： Amorphous Sb/C anode Homogeneous element distribution Isotropic volume expansion Ultra-long cycle stability High-rate capability Lithium-ion battery

Supramolecular polymer-based gel fracturing fluid with a double network applied in ultra-deep hydraulic fracturing

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Petroleum Science 2024年第3期21卷 1875-1888页

作者： Yong-ping Huang Yong Hu Chang-Long Liu Yi-Ning Wu Chen-Wei Zou Li-Yuan zhang Ming-Wei zhao Cai-Li Dai School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China Shandong Key Laboratory of Oilfield Chemistry China University of Petroleum(East China)Qingdao 266580ShandongPR China SINOPEC Petroleum Exploration and Production Research Institute Beijing102206PR China CNOOC China Co Ltd Tianjin BranchTianjin300459PR China

A gel based on polyacrylamide,exhibiting delayed crosslinking characteristics,emerges as the preferred solution for mitigating degradation under conditions of high temperature and extended shear in ultralong *** viscosity/viscoelasticity of the fracturing fluid was required to maintain excellent proppant suspension properties before *** into account both the cost and the potential damage to reservoirs,polymers with lower concentrations and molecular weights are generally *** this work,the supramolecular action was integrated into the polymer,resulting in significant increases in the viscosity and viscoelasticity of the synthesized supramolecular polymer *** double network gel,which is formed by the combination of the supramolecular polymer system and a small quantity of Zr-crosslinker,effectively resists temperature while minimizing permeability damage to the *** results indicate that the supramolecular polymer system with a molecular weight of(268—380)×10^(4)g/mol can achieve the same viscosity and viscoelasticity at 0.4 wt%due to the supramolecular interaction between polymers,compared to the 0.6 wt%traditional polymer(hydrolyzed polyacrylamide,molecular weight of 1078×10^(4)g/mol).The supramolecular polymer system possessed excellent proppant suspension properties with a 0.55 cm/min sedimentation rate at 0.4 wt%,whereas the0.6 wt%traditional polymer had a rate of 0.57 cm/*** comparison to the traditional gel with a Zrcrosslinker concentration of 0.6 wt%and an elastic modulus of 7.77 Pa,the double network gel with a higher elastic modulus(9.00 Pa)could be formed only at 0.1 wt%Zr-crosslinker,which greatly reduced the amount of residue of the fluid after *** viscosity of the double network gel was66 m Pa s after 2 h shearing,whereas the traditional gel only reached 27 m Pa s.

关键词： Ultra-deep reservoir Gel fracturing fluid Double network Supramolecular polymer system Proppant suspension property

Automatic detection of small bowel lesions with different bleeding risks based on deep learning models

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World Journal of Gastroenterology 2024年第2期30卷 170-183页

作者： Rui-Ya zhang Peng-Peng Qiang Ling-Jun Cai Tao Li Yan Qin Yu zhang Yi-Qing zhao Jun-ping Wang Department of Gastroenterology The Fifth Clinical Medical College of Shanxi Medical UniversityTaiyuan 030012Shanxi ProvinceChina School of Computer and Information Technology Shanxi UniversityTaiyuan 030006Shanxi ProvinceChina School of Life Sciences and Technology Mudanjiang Normal UniversityMudanjiang 157011Heilongjiang ProvinceChina

BACKGROUND Deep learning provides an efficient automatic image recognition method for small bowel(SB)capsule endoscopy(CE)that can assist physicians in ***,the existing deep learning models present some unresolved *** To propose a novel and effective classification and detection model to automatically identify various SB lesions and their bleeding risks,and label the lesions accurately so as to enhance the diagnostic efficiency of physicians and the ability to identify high-risk bleeding *** The proposed model represents a two-stage method that combined image classification with object ***,we utilized the improved ResNet-50 classification model to classify endoscopic images into SB lesion images,normal SB mucosa images,and invalid ***,the improved YOLO-V5 detection model was utilized to detect the type of lesion and its risk of bleeding,and the location of the lesion was *** constructed training and testing sets and compared model-assisted reading with physician *** The accuracy of the model constructed in this study reached 98.96%,which was higher than the accuracy of other systems using only a single *** sensitivity,specificity,and accuracy of the model-assisted reading detection of all images were 99.17%,99.92%,and 99.86%,which were significantly higher than those of the endoscopists’*** image processing time of the model was 48 ms/image,and the image processing time of the physicians was 0.40±0.24 s/image(P<0.001).CONCLUSION The deep learning model of image classification combined with object detection exhibits a satisfactory diagnostic effect on a variety of SB lesions and their bleeding risks in CE images,which enhances the diagnostic efficiency of physicians and improves the ability of physicians to identify high-risk bleeding groups.

关键词： Artificial intelligence Deep learning Capsule endoscopy Image classification Object detection Bleeding risk

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