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Three‑dimensional numerical simulation of dynamic strength and failure mode of a rock mass with cross joints

International Journal of Coal Science & Technology 2024年第2期11卷 35-52页

作者： Tingting Liu Wenxu Huang Chang Xiang Qian Dong Xinping Li Chao zhang Hubei Key Laboratory of Blasting Engineering Jianghan UniversityWuhan 430056China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China Hainan Institute Wuhan University of TechnologySanya 572025China

To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure,considering the cross angleαand joint persistence ratioη,a numerical model of the biaxial Hopkinson bar test system was established using the finite element method–discrete-element model coupling *** validity of the model was verified by comparing and analyzing it in conjunction with laboratory test ***-static combined impact tests were conducted on specimens under various conditions to investigate the strength characteristics and patterns of crack initiation and *** study revealed the predominant factors influencing intersecting joints with different angles and penetrations under impact *** results show that the peak stress of the specimens decreases first and then increases with the increase of the cross ***α<60°,regardless of the value ofη,the dynamic stress of the specimens is controlled by the main ***α≥60°,the peak stress borne by the specimens decreases with increasingη.Whenα<60°,the initiation and propagation of cracks in the cross-jointed specimens are mainly controlled by the main joint,and the final failure surface of the specimens is composed of the main joint and wing ***α≥60°orη≥0.67,the secondary joint guides the expansion of the wing cracks,and multiple failure surfaces composed of main and secondary joints,wing cracks,and co-planar cracks are *** lateral confinement significantly increases the dynamic peak stress able to be borne by the *** triaxial conditions,the degree of failure of the intersecting jointed specimens is much lower than that under uniaxial and biaxial conditions.

关键词： Cross joints Joint distribution form Dynamic failure characteristics FEM–DEM BHPB

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Revolutionizing tumor immunotherapy:unleashing the power of progenitor exhausted T cells

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Cancer Biology & Medicine 2024年第6期21卷 499-512页

作者： zhang Fang Xinyi Ding Hao Huang Hongwei Jiang Jingting Jiang Xiao Zheng Department of Tumor Biological Treatment The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China Jiangsu Engineering Research Center for Tumor Immunotherapy The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China Institute for Cell Therapy of Soochow University The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China

In exploring persistent infections and malignancies, a distinctive subgroup of CD8^(+) T cells, progenitor exhausted CD8^(+) T(Tpex) cells, has been identified. These Tpex cells are notable for their remarkable self-renewal and rapid proliferation abilities. Recent strides in immunotherapy have demonstrated that Tpex cells expand and differentiate into responsive exhausted CD8^(+) T cells, thus underscoring their critical role in the immunotherapeutic retort. Clinical examinations have further clarified a robust positive correlation between the proportional abundance of Tpex cells and enhanced clinical prognosis. Tpex cells have found noteworthy applications in the formulation of inventive immunotherapeutic approaches against tumors. This review describes the functions of Tpex cells in the tumor milieu, particularly their potential utility in tumor immunotherapy. Precisely directing Tpex cells may be essential to achieving successful outcomes in immunotherapy against tumors.

关键词： Progenitor exhausted CD8^(+)T cells TCF-1 immunotherapy tumor microenvironment cellular crosstalk

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Early peripheral perfusion index predicts 28-day outcome in patients with septic shock

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World Journal of Emergency Medicine 2024年第5期15卷 372-378页

作者： Cheng Chi Hao Gong Kai yang Peng Peng Xiaoxia zhang Department of Emergency Peking University People's HospitalBeijing 100044China Department of Emergency Intensive Care Unit the First Affi liated Hospital of Xinjiang Medical UniversityUrumqi 830000China

BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic ***:This prospective cohort study,conducted at the emergency intensive care unit of Peking University People's Hospital,recruited 200 patients with septic shock between January 2023 and August *** patients were divided into survival(n=84)and death(n=116)groups based on 28-day *** evaluations included laboratory tests and clinical scores,with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 12 h after *** factors associated with mortality were analyzed using univariate and multivariate Cox regression *** operator characteristic(ROC)curve was used to assess predictive *** rates were compared,and Kaplan-Meier survival plots were ***:Compared to the survival group,patients in the death group were older and had more severe liver damage and coagulation dysfunction,necessitating higher norepinephrine doses and increased fl uid *** lactate levels and lower PPI levels at 0 h,6 h,and 12 h were observed in the death *** Cox regression identifi ed prolonged prothrombin time(PT),decreased 6-h PPI and 12-h PPI as independent risk factors for *** area under the curves for 6-h PPI and 12-h PPI were 0.802(95%CI 0.742-0.863,P<0.001)and 0.945(95%CI 0.915-0.974,P<0.001),respectively,which were superior to Glasgow Coma Scale(GCS),Sequential Organ Failure Assessment(SOFA)scores(0.864 and 0.928).Cumulative mortality in the low PPI groups at 6 h and 12 h was signifi cantly higher than in the high PPI groups(6-h PPI:77.52%vs.22.54%;12-h PPI:92.04%vs.13.79%,P<0.001).CONCLUSION:PPI may have value in predicting 28-day mortality in patients with septic shock.

关键词： Peripheral perfusion index Septic shock Prognosis Predictive value

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On electro-acoustic characteristics of a marine broadband sparker for seismic exploration

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Journal of Oceanology and Limnology 2024年第3期42卷 760-771页

作者： Jing LI Kai LIU Liancheng zhang Chenguang LIU yanliang PEI Baohua LIU Key Laboratory of Marine Geology and Metallogency First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory of Marine Geology Laoshan LaboratoryQingdao 266237China Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou 310018China Key Laboratory of Submarine Acoustic Investigation and Application of Qingdao(Preparatory) Qingdao 266061China Key Laboratory of Deep Sea Mineral Resources Development Shandong(Preparatory)Qingdao 266061China

The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and *** highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify *** optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode *** show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage *** addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level *** the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency ***,the primary to bubble(P/B)ratio increased with the increase of the electrode *** gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was ***,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per *** results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 *** last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 *** study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.

关键词： high-resolution marine seismic exploration sparker seismic source sound source level main frequency electro-acoustic characteristics

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Real-time tracking of fast-moving object in occlusion scene

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Journal of Systems Engineering and Electronics 2024年第3期35卷 741-752页

作者： LI Yuran LI Yichen zhang Monan YU Wenbin GUAN Xinping Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Systems Control and Information Processing Ministry of Education of ChinaShanghai 200240China

Tracking the fast-moving object in occlusion situations is an important research topic in computer vision. Despite numerous notable contributions have been made in this field,few of them simultaneously incorporate both object's extrinsic features and intrinsic motion patterns into their methodologies,thereby restricting the potential for tracking accuracy improvement. In this paper, on the basis of efficient convolution operators(ECO) model, a speed-accuracy-balanced model is put forward. This model uses the simple correlation filter to track the object in real-time, and adopts the sophisticated deep-learning neural network to extract high-level features to train a more complex filter correcting the tracking mistakes, when the tracking state is judged to be poor. Furthermore, in the context of scenarios involving regular fast-moving, a motion model based on Kalman filter is designed which greatly promotes the tracking stability, because this motion model could predict the object's future location from its previous movement pattern. Additionally,instead of periodically updating our tracking model and training samples, a constrained condition for updating is proposed,which effectively mitigates contamination to the tracker from the background and undesirable samples avoiding model degradation when occlusion happens. From comprehensive experiments, our tracking model obtains better performance than ECO on object tracking benchmark 2015(OTB100), and improves the area under curve(AUC) by about 8% and 32% compared with ECO, in the scenarios of fast-moving and occlusion on our own collected dataset.

关键词： speed-accuracy balanced motion modeling constrained updater

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Retrieval of Antarctic sea ice freeboard and thickness from HY-2B satellite altimeter data

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Acta Oceanologica Sinica 2024年第3期43卷 87-101页

作者： Yizhuo Chen Xiaoping Pang Qing Ji Zhongnan yan Zeyu Liang Chenlei zhang Chinese Antarctic Center of Surveying and Mapping Wuhan UniversityWuhan 430079China Key Laboratory of Polar Surveying and Mapping Science Ministry of Natural ResourcesWuhan 430079China Key Laboratory of Polar Environment Monitoring and Public Governance Ministry of EducationWuhan 430079China 4 School of Geography and Tourism Anhui Normal UniversityWuhu 241002China

Antarctic sea ice is an important part of the Earth’s atmospheric system,and satellite remote sensing is an important technology for observing Antarctic sea *** Chinese Haiyang-2B(HY-2B)satellite altimeter data could be used to estimate sea ice freeboard and provide alternative Antarctic sea ice thickness information with a high precision and long time series,as other radar altimetry satellites can,needs further *** paper proposed an algorithm to discriminate leads and then retrieve sea ice freeboard and thickness from HY-2B radar altimeter *** first collected the Moderate-resolution Imaging Spectroradiometer ice surface temperature(IST)product from the National Aeronautics and Space Administration to extract leads from the Antarctic waters and verified their accuracy through Sentinel-1 Synthetic Aperture Radar ***,a surface classification decision tree was generated for HY-2B satellite altimeter measurements of the Antarctic waters to extract leads and calculate local sea surface *** then estimated the Antarctic sea ice freeboard and thickness based on local sea surface heights and the static equilibrium ***,the retrieved HY-2B Antarctic sea ice thickness was compared with the CryoSat-2 sea ice thickness and the Antarctic Sea Ice Processes and Climate(ASPeCt)ship-based observed sea ice *** results indicate that our classification decision tree constructed for HY-2B satellite altimeter measurements was reasonable,and the root mean square error of the obtained sea ice thickness compared to the ship measurements was 0.62 *** proposed sea ice thickness algorithm for the HY-2B radar satellite fills a gap in this application domain for the HY-series satellites and can be a complement to existing Antarctic sea ice thickness products;this algorithm could provide long-time-series and large-scale sea ice thickness data that contribute to research on global climate change.

关键词： HY-2B satellite altimeter classification decision tree sea ice freeboard and thickness Antarctic waters

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Overhead-free Noise-tolerant Federated Learning: A New Baseline

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Machine Intelligence Research 2024年第3期21卷 526-537页

作者： Shiyi Lin Deming Zhai Feilong zhang Junjun Jiang Xianming Liu Xiangyang Ji Department of Computer Science and Technology Harbin Institute of TechnologyHarbin150000China Department of Automation Tsinghua UniversityBeijing100084China

Federated learning (FL) is a promising decentralized machine learning approach that enables multiple distributed clients to train a model jointly while keeping their data private. However, in real-world scenarios, the supervised training data stored in local clients inevitably suffer from imperfect annotations, resulting in subjective, inconsistent and biased labels. These noisy labels can harm the collaborative aggregation process of FL by inducing inconsistent decision boundaries. Unfortunately, few attempts have been made towards noise-tolerant federated learning, with most of them relying on the strategy of transmitting overhead messages to assist noisy labels detection and correction, which increases the communication burden as well as privacy risks. In this paper, we propose a simple yet effective method for noise-tolerant FL based on the well-established co-training framework. Our method leverages the inherent discrepancy in the learning ability of the local and global models in FL, which can be regarded as two complementary views. By iteratively exchanging samples with their high confident predictions, the two models “teach each other” to suppress the influence of noisy labels. The proposed scheme enjoys the benefit of overhead cost-free and can serve as a robust and efficient baseline for noise-tolerant federated learning. Experimental results demonstrate that our method outperforms existing approaches, highlighting the superiority of our method.

关键词： Federated learning noise-label learning privacy-preserving machine learning edge intelligence distributed machine learning

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Temporal and spatial evolution of global major grain trade patterns

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Journal of Integrative Agriculture 2024年第3期23卷 1075-1086页

作者： Ziqi Yin Jiaxuan Hu Jing zhang Xiangyang Zhou Lingling Li Jianzhai Wu Agricultural Information Institute Chinese Academy of Agricultural SciencesBeijing 100081China Institute of Scientific and Technical Information of China Beijing 100038China Zibo Agricultural Science Research Institute Zibo 255000China Zibo Institute for Digital Agriculture and Rural Research Zibo 255000China

The complex and volatile international landscape has significantly impacted global grain supply security. This study uses a complex network analysis model to examine the evolution and trends of the global major grain trade from 1990 to 2020, focusing on network topology, centrality ranking, and community structure. There are three major findings. First, the global major grain trade network has expanded in scale, with a growing emphasis on diversification and balance. During the study period, the United States, Canada, China, and Brazil were the core nodes of the network. Grain-exporting countries were mainly situated in Asia, the Americas, and Europe, and importing countries in Asia, Africa, and Europe. Second, a significant increase in the number of high centrality countries with high export capacity occurred, benefiting from natural advantages such as fertile land and favorable climates. Third, the main global grain trade network is divided into four communities, with the Americas-Europe community being the largest and most widespread. The formation of the community pattern was influenced by geographic proximity, driven by the core exporting countries. Therefore, the world needs to enhance the existing trade model, promote the multi-polarization of the grain trade network, and establish a global vision for the future community. Countries and regions should participate actively in global grain trade security governance and institutional reform, expand trade links with other countries, and optimize import and export policies to reduce trade risks.

关键词： grain trade pattern evolution complex network

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Agronomic performances of biodegradable and non-biodegradable plastic film mulching on a maize cropping system in the semi-arid Loess Plateau,China

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Pedosphere 2024年第1期34卷 88-96页

作者： Hao zhang Mengqiong CHEN Ruiquan QIAO Fan DING Hao FENG Rui JIANG Research Center for Cultural Landscape Protection and Ecological Restoration China-Portugal Belt and Road Cooperation Laboratory of Cultural Heritage Conservation ScienceGold Mantis School of ArchitectureSoochow UniversitySuzhou 215006China Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of AgricultureCollege of Natural Resources and EnvironmentNorthwest A&F UniversityYangling 712100China College of Land and Environment Shenyang Agricultural UniversityShenyang 110866China Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100China

Biodegradable plastic film mulch (PFM) is considered an alternative to non-biodegradable PFM to mitigate the negative impacts of residual ***,the agronomic performance of biodegradable PFM in comparison to non-biodegradable PFM still needs to be *** this study,we evaluated the effects of biodegradable and non-biodegradable PFM on soil physicochemical properties,microbial community,and enzyme activities,as well as maize growth *** and non-biodegradable PFM both increased soil temperature,water content,N content,and microbial biomass and maize yield by up to 30%,but decreased soil enzyme activities as compared to no mulching (control,CK).Most soil physicochemical properties,microbial community,and enzyme activities were similar under non-biodegradable and biodegradable PFM at the early stages of maize ***,at the late stages,soil temperature,water content,mineral N,NO_(3)^(-)-N,ammonia monooxygenase (AMO) activity,and total phospholipid fatty acids (PLFAs) decreased under biodegradable PFM owing to film *** PFM increased soil temperature,water content,and total PLFAs at the early stages of maize growth but decreased soil mineral N and total PLFAs at the late stages,as compared to black *** soil temperature and N availability were the major factors affecting soil microbial community,microbial activity decreased after the fragmentation of biodegradable PFM,owing to the decreased soil temperature,water content,and mineral ***,biodegradable PFM could decrease NO_(3)^(-)-N accumulation in topsoil by decreasing N transformation due to the lower microbial and N-related enzyme (e.g.,AMO) activities,compared with non-biodegradable PFM,which may avoid negative environmental impacts,such as NO_(3)^(-)-N leaching or gas emission after *** yield,height,aboveground biomass,and N uptake under biodegradable PFM were similar to those under non-biodegradable PFM during maize growth,implying that biodegrad

关键词： black plastic film mulching enzyme activity film fragmentation microbial community phospholipid fatty acid white plastic film mulching

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Effect of wall-disruption on nutrient composition and in vitro digestion of camellia and lotus bee pollens

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Food Science and Human Wellness 2024年第3期13卷 1567-1577页

作者： Yuan Yuan Shun Zhong Zeyuan Deng Guangyan Li Jinwu zhang Hongyan Li State Key Laboratory of Food Science and Resources Nanchang UniversityNanchang 330047China Nanchang Tongxin Zichao Biological Engineering Co. Ltd.Nanchang 330052China

The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen ***,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this *** showed that the content of nutrients in bee pollen increased after wall *** them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher *** activities during in vitro digestion were also improved in walldisruption bee *** findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.

关键词： Bee pollen Nutrients Wall disruption Phenolic compounds In vitro digestion

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