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Numerical simulation on directional solidification and heat treatment processes of turbine blades

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China Foundry 2024年第5期21卷 476-490页

作者： Ye-yuan Hu ju-huai Ma qing-yan Xu School of Materials Science and Engineering Tsinghua UniversityKey Laboratory for Advanced Materials Processing TechnologyMinistry of EducationBeijing 100084China

Study on turbine blades is crucial due to their critical role in ensuring the efficient and reliable operation of aircraft ***-based single crystal superalloys are extensively used in the hot manufacturing of turbine blades due to their exceptional high-temperature mechanical *** hot manufacturing of single crystal blades involves directional solidification and heat *** manufacturing of these blades is time-consuming,capital-intensive,and often insufficient to meet industrial *** simulation techniques have gained widespread acceptance in blade manufacturing research due to their low energy consumption,high efficiency,and rapid turnaround *** article introduces the modeling and simulation of hot manufacturing in single crystal *** discussion outlines the prevalent mathematical models employed in numerical simulations related to blade hot *** encapsulates the advancements in research concerning macro to micro-level numerical simulation techniques for directional solidification and heat treatment ***,potential future trajectories for the numerical simulation of single crystal blade hot manufacturing are also discussed.

关键词： single crystal blades Ni-based superalloy directional solidification heat treatment numerical simulation

Robust and Discriminative Feature Learning via Mutual Information Maximization for Object Detection in Aerial Images

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Computers, Materials & Continua 2024年第9期80卷 4149-4171页

作者： Xu sun Yinhui Yu qing Cheng School of Communication Engineering Jilin UniversityChangchun130012China

Object detection in unmanned aerial vehicle(UAV)aerial images has become increasingly important in military and civil *** object detection models are not robust enough against interclass similarity and intraclass variability of small objects,and UAV-specific nuisances such as uncontrolledweather *** previous approaches focusing on high-level semantic information,we report the importance of underlying features to improve detection accuracy and robustness fromthe information-theoretic ***,we propose a robust and discriminative feature learning approach through mutual information maximization(RD-MIM),which can be integrated into numerous object detection methods for aerial ***,we present the rank sample mining method to reduce underlying feature differences between the natural image domain and the aerial image ***,we design a momentum contrast learning strategy to make object features similar to the same category and dissimilar to different ***,we construct a transformer-based global attention mechanism to boost object location semantics by leveraging the high interrelation of different receptive *** conduct extensive experiments on the VisDrone and Unmanned Aerial Vehicle Benchmark Object Detection and Tracking(UAVDT)datasets to prove the effectiveness of the proposed *** experimental results show that our approach brings considerable robustness gains to basic detectors and advanced detection methods,achieving relative growth rates of 51.0%and 39.4%in corruption robustness,*** code is available at https://***/cq100/RD-MIM(accessed on 2 August 2024).

关键词： Aerial images object detection mutual information contrast learning attention mechanism

Cascade electrolysis and thermocatalysis: a reliable system for upgrading C1 to C4 hydrocarbons

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Rare Metals 2024年第1期43卷 410-412页

作者： Chao-Yue sun Wen Li Hai-qing Wang Institute for Advanced Interdisciplinary Research(iAIR) College of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China

The carbon cycle is important for maintaining a stable climate and carbon balance on Earth. Renewable-electricitydriven upcycling of carbon dioxide (CO_(2)) into value-added multi-carbon molecules is a potentially sus... 详细信息

关键词： cycling hydrocarbons enable

Towards the universal defense for query-based audio adversarial attacks on speech recognition system

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Cybersecurity 2024年第1期7卷 53-70页

作者： Feng Guo Zheng sun Yuxuan Chen Lei ju School of Cyber Science and Technology Shandong UniversityQingdaoChina Quancheng Laboratory QCLJinanChina

Recently,studies show that deep learning-based automatic speech recognition(ASR)systems are vulnerable to adversarial examples(AEs),which add a small amount of noise to the original audio *** AE attacks pose new challenges to deep learning security and have raised significant concerns about deploying ASR systems and *** existing defense methods are either limited in application or only defend on results,but not on *** this work,we propose a novel method to infer the adversary intent and discover audio adversarial examples based on the AEs generation *** insight of this method is based on the observation:many existing audio AE attacks utilize query-based methods,which means the adversary must send continuous and similar queries to target ASR models during the audio AE generation *** by this observation,We propose a memory mechanism by adopting audio fingerprint technology to analyze the similarity of the current query with a certain length of memory ***,we can identify when a sequence of queries appears to be suspectable to generate audio *** extensive evaluation on four state-of-the-art audio AE attacks,we demonstrate that on average our defense identify the adversary’s intent with over 90%*** careful regard for robustness evaluations,we also analyze our proposed defense and its strength to withstand two adaptive ***,our scheme is available out-of-the-box and directly compatible with any ensemble of ASR defense models to uncover audio AE attacks effectively without model retraining.

关键词： Adversarial attacks Defense Memory mechanism Query-based

Integral precession calibration method of PIGA on linear vibration table

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Chinese Journal of Aeronautics 2024年第3期37卷 219-236页

作者： Chuang sun Shun-qing REN jun-wei CAO Ru HUO Department of Automation Tsinghua UniversityBeijing 100084China School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China Faculty of Information technology Beijing University of TechnologyBeijing 100124China

Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a linear vibration table in this *** on the precise expressions of PIGA’s inputs,the error calibration model of PIGA is *** angular velocity errors of PIGA are suppressed by integer periodic precession and the errors caused by non-integer periods vibrating are *** complete calibration process,including planning,preparation,PIGA testing,and coefficient identification,is designed to optimize the test operations and evaluate the calibration *** effect of the main errors on calibration uncertainty is analyzed and the relative sensitivity function is proposed to further optimize the test *** and simulation results verify that the proposed 10-position calibration method can improve calibration uncertainties after compensating for the related *** order of calibration uncertainties of the second-and third-order coefficients are decreased to 10^(-8)(rad.s^(-1))/g^(2)and 10^(-8)(rad.s^(-1))/g3,*** with the other two classical calibration methods,the calibration uncertainties of PIGA’s nonlinear error coefficients can be effectively reduced and the proportional residual errors are decreased less than 3×10-6(rad.s^(-1))/g by using the proposed calibration method.

关键词： PIGA Linear vibration table Vibration measurement Calibration Error analysis Uncertainty analysis

Celastrus orbiculatus Extract Inhibits Immune Inflammatory Thrombotic State of B-Lymphoma

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Chinese Journal of Integrative Medicine 2024年第11期30卷 1018-1026页

作者： ZHU Miao SHI qing-qing NI jun WU Wei sun Xing sun Mei XU Kai-lin LIU Yan-qing GU Jian GU Hao Department of Hematology Clinical Medical Col ege Yangzhou University Yangzhou Institute of Hematology Department of Hematology The Affiliated Hospital of Xuzhou Medical University Department of Oncology The Affiliated Hospital of Yangzhou University Yangzhou University Department of Neurology The Affiliated Brain Hospital of Nanjing Medical University

Objective:To investigate the inhibitory effect of Celastrus orbiculatus extracts（COE） on the proliferation of lymphoma cells and the immune regulation ability on inflammation and thrombophilia in ***:The 38B9 lymphoma cells were treated with COE（160μg/mL） and CTX（25 μmol/L）.The apoptosis rate and cell cycle of each group were detected by flow *** secretion of inflammatory factors,including interleukin（IL）-6,IL-10,and tumor necrosis factor α（TNF-α）,in cell supernatant was detected by enzyme-linked immunosorbent assay（ELISA）.In vivo,BALB/c mice were subcutaneously injected with 38B9 lymphoma cells to establish lymphoma ***(3 mg·kg-1·d-1) and CTX(40 mg-kg-1·d-1) were administered to the model mice,*** expression of plasma inflammatory factors（IL-6,IL-10 and TNF-α） and thrombus indexes,including D-dimer（D-D）,von Willebrand factor（vWF） and tissue factor（TF）,were detected by ELISA before tumor bearing（1 d）,after tumor formation（14 d） and after intervention（21 d）.PicoGreen dsDNA was used to detect the level of serum neutrophil extracellular traps（NETs）.Flow cytometry was used to detect the expression of platelet activation marker calcium-dependent lectin-like receptor 2（CLEC-2）.The tumor growth and survival of mice were ***:The 38B9 lymphoma cells were apoptotic after the intervention of COE and *** ratio of G2-M phase cells decreased in COE intervented cells compared with the control cells（P<0.05）,and S phase cells decreased in CTX intervented cells（P<0.05）.Also,the secretion level of IL-6 was significantly reduced after COE or CTX intervention（P<0.05）,and IL-10 was significantly increased（P<0.05）.Furthermore,the tumor mass was reduced,and the median survival time was longer in COE and CTX intervented tumor-bearing mice than in nonintervented *** significantly lower levels of TNF-α,IL-6,NETs,TF,DD and CLEC-2,as well as higher IL-10 were observed in COE and CTX treatment mice in comparision with the control mice（P

关键词： Celastrus orbiculatus extract immune regulation lymphoma murine lymphoma cells proliferation inhibition thrombotic state tumor inflammation

Cubic S/N co-doped TiO_(2) with rich oxygen vacancies from Ti-MOFs for efficient elimination of formaldehyde

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Chinese Chemical Letters 2024年第2期35卷 512-515页

作者： qing Gao Lei sun Zhihua Wang Jiguang Deng State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaDepartment of Chemical EngineeringBeijing University of TechnologyBeijing 100124China

The cubic S/N co-doped TiO_(2)(TNSx,x is the calcination temperature)photocatalysts with rich oxygen vacancies were obtained by high temperature calcination of sulfur powder and titanium-based MOFs NH_(2)-MIL-125 for the photocatalytic removal of gaseous formaldehyde(a volatile organic compound).Among the obtained catalysts,the presence of oxygen vacancies restricted photogenerated electron and holes recombination.98.00%removal of gaseous formaldehyde in 150 min could be achieved over TNS600 by xenon *** removal efficiency for formaldehyde was well retained for five cycle *** results from PL,TRPL and EIS revealed that TNS600 had the best separation efficiency of photogenerated electrons and holes,and the enhanced charge separation led to a significant increase in photocatalytic *** photocatalytic oxidation mechanism indicated that the ^(•)OH and ^(•)O_(2)−radicals were mainly involved in the efficient elimination of gaseous formaldehyde and were able to mineralize formaldehyde to H_(2)O and CO_(2).

关键词： Metal-organic frameworks Photocatalysis Formaldehyde removal S/N co-doped TiO_(2) Oxygen vacancies

Potential for soil carbon sequestration under conservation agriculture in a warming climate

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Science Bulletin 2024年第13期69卷 2030-2033页

作者： Lijun Yu Wen Zhang Jingjing Liu Wenjuan sun qing Zhang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Anyang Meteorological Service Anyang 455000China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Agricultural soil has numerous links with climate *** comprises a substantial part of farming systems that are affected by climate change and can significantly impact food security[1].An increase in the soil carbon(C)stock is associated with an increase in the crop ***,agricultural soil remains a source for all three major greenhouse gases(GHGs),i.e.,carbon dioxide(CO_(2)),methane and nitrous oxide,which contributes directly to climate *** addition,enhancing soil C sequestration in agricultural land could offset GHG emissions,promote more sustainable and climate-resilient agricultural systems.

关键词： soil warming agricultural

Visual Semantic Segmentation Based on Few/Zero-Shot Learning:An Overview

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1106-1126页

作者： Wenqi Ren Yang Tang Qiyu sun Chaoqiang Zhao qing-Long Han Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China National Key Laboratory of Air-Based Information Perception and Fusion Aviation Industry Corporation of ChinaLuoyang 471000China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Visual semantic segmentation aims at separating a visual sample into diverse blocks with specific semantic attributes and identifying the category for each block,and it plays a crucial role in environmental *** learning-based visual semantic segmentation approaches count heavily on largescale training data with dense annotations and consistently fail to estimate accurate semantic labels for unseen *** obstruction spurs a craze for studying visual semantic segmentation with the assistance of few/zero-shot *** emergence and rapid progress of few/zero-shot visual semantic segmentation make it possible to learn unseen categories from a few labeled or even zero-labeled samples,which advances the extension to practical ***,this paper focuses on the recently published few/zero-shot visual semantic segmentation methods varying from 2D to 3D space and explores the commonalities and discrepancies of technical settlements under different segmentation ***,the preliminaries on few/zeroshot visual semantic segmentation,including the problem definitions,typical datasets,and technical remedies,are briefly reviewed and ***,three typical instantiations are involved to uncover the interactions of few/zero-shot learning with visual semantic segmentation,including image semantic segmentation,video object segmentation,and 3D ***,the future challenges of few/zero-shot visual semantic segmentation are discussed.

关键词： Visual segmentation separating