检索结果-南通市图书馆

MCS-based quantile value approach for reliability-based design of tunnel face support pressure

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第5期18卷 187-198页

作者： bin li Changxing Wang {2. li Department of Road and Bridge Engineering School of Transportation and Logistics EngineeringWuhan University of TechnologyWuhan 430063China Hubei Highway Engineering Research Center Wuhan 430063China

This paper develops a new approach for reliability-based design(RBD)of tunnel face support pressure from a quantile value perspective.A surrogate model is constructed to calculate the collapse pressures of the random samples generated by a single run of Monte Carlo simulation(MCS).The cumulative distribution function(CDF)of the collapse pressure is then obtained and the support pressure aiming at a target failure probability is chosen as the upper quantile value of the collapse *** proposed approach does not require repetitive reliability analyses compared to the existing ***,a direct relationship between the target failure probability and the required support pressure is *** illustrative example is used to demonstrate the implementation *** accuracy of the reliability-based support pressures is verified by direct MCS incorporating with three-dimensional numerical ***,the influencing factors,including the sample size of MCS,the correlation coefficient between random variables,the choice of experimental points,and the surrogate model,are *** method can play a complementary role to available approaches due to its advantages of simplicity and efficiency.

关键词： Tunnel face stability Support pressure Reliability-based design Response surface method Monte Carlo simulation

Unsupervised Multi-Expert Learning Model for Underwater Image Enhancement

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 708-722页

作者： hongmin liu {2. Zhang Yufan Hu Hui Zeng bin fan the school of Intelligence Science and Technology and the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the school of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China IEEE

Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded *** methods feed the whole image directly into the model for ***,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the *** address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color ***,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater *** on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater ***,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,*** addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced *** experiments on public datasets demonstrate that our method achieves more pleasing results in vision *** metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.

关键词： Multi-expert learning underwater image enhancement unsupervised learning

An Overview on Wavelet Software Packages

在线全文

学校读者我要写书评

暂无评论

wuhan University Journal of Natural Sciences 2001年第Z1期6卷 593-600页

作者： fan qi\|{2. 1, li hong 2.1. school of mathematics and statistics, wuhan University, wuhan 430072, china 2. school of Electronic Information, wuhan University, wuhan 430072, china school of mathematics and {2. Wuhan University Wuhan China school of Electronic Information Wuhan University Wuhan China

Wavelet analysis provides very powerful problem\|solving tools for analyzing, encoding, compressing, reconstructing, and modeling signals and images. The amount of wavelets\|related software has been constantly multiplying. Many wavelet analysis tools are widely available. This overview represents a significant survey for many currently available packages. It will be of great benefit to engineers and researchers for using the toolkits and developing new software. The beginner to learning wavelets can also get a great help from the review. If you browse around at some of the Internet sites listed in the reference of this paper, you may find more plentiful wavelet resources.

关键词： wavelet transforms image compression matching pursuit lifting MATLAB

Research on the solid particle erosion wear of pipe steel for hydraulic fracturing based on experiments and numerical simulations

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2779-2792页

作者： Si-qi Yang Jian-Chun fan Ming-Tao {2.u De-Ning {2. Jun-{2.ang {2. {2.-hong Han Jian-Jun Wang Shang-Yu Yang Si-Wei Dai Lai-bin Zhang State Key Laboratory of Oil and Gas Equipment CNPC Tubular Goods Research Institute Key Laboratory of Oil and Gas Safety and Emergency Technology China University of Petroleum Oil Production Technology Research Institute of liaohe Oilfield Company Tianjin Gas Storage Branch PetroChina Dagang Oilfield Company Petroleum Production Engineering Research Institute Daqing Oilfield Company

Erosion wear is a common failure mode in the oil and gas industry. In the hydraulic fracturing, the fracturing pipes are not only in high-pressure working environment, but also suffer from the impact of the high-speed solid particles in the fracturing fluid. Beneath such complex conditions, the vulnerable components of the pipe system are prone to perforation or even burst accidents, which has become one of the most serious risks at the fracturing site. Unfortunately, it is not yet fully understood the erosion mechanism of pipe steel for hydraulic fracturing. Therefore, this article provides a detailed analysis of the erosion behavior of fracturing pipes under complex working conditions based on experiments and numerical simulations. Firstly, we conducted erosion experiments on AISI 4135 steel for fracturing pipes to investigate the erosion characteristics of the material. The effects of impact angle, flow velocity and applied stress on erosion wear were comprehensively considered. Then a particle impact dynamic model of erosion wear was developed based on the experimental parameters, and the evolution process of particle erosion under different impact angles, impact velocities and applied stress was analyzed. By combining the erosion characteristics, the micro-structure of the eroded area, and the micro-mechanics of erosion damage, the erosion mechanism of pipe steel under fracturing conditions was studied in detail for the first time. Under high-pressure operating conditions, it was demonstrated through experiments and numerical simulations that the size of the micro-defects in the eroded area increased as the applied stress increased, resulting in more severe erosion wear of fracturing pipes.

关键词： Erosion wear Applied stress Particle impact dynamics Erosion mechanism

Advanced Design of Soft Robots with Artificial Intelligence

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第10期16卷 474-521页

作者： Ying Cao bingang Xu bin {2. hong Fu Nanotechnology Center School of Fashion and TextilesThe Hong Kong Polytechnic UniversityHong Kong 999077People's Republic of China Department of mathematics and Information Technology The Education University of Hong KongHong Kong 999077People's Republic of China Bioinspired Engineering and Biomechanics Center Xi'an Jiaotong UniversityXi'an 710049People's Republic of China

In recent years,breakthrough has been made in the field of artificial intelligence(AI),which has also revolutionized the industry of *** robots featured with high-level safety,less weight,lower power consumption have always been one of the research ***,multifunctional sensors for perception of soft robotics have been rapidly developed,while more algorithms and models of machine learning with high accuracy have been optimized and *** of soft robots with AI have also been advanced ranging from multimodal sensing,human-machine interaction to effective actuation in robotic ***-less,comprehensive reviews concerning the new developments and strategies for the ingenious design of the soft robotic systems equipped with AI are ***,the new development is systematically reviewed in the field of soft robots with ***,background and mechanisms of soft robotic systems are briefed,after which development focused on how to endow the soft robots with AI,including the aspects of feeling,thought and reaction,is ***,applications of soft robots with AI are systematically summarized and discussed together with advanced strategies proposed for performance *** thoughts for future intelligent soft robotics are pointed ***,some perspectives are put forward.

关键词： Soft robotic systems Artificial intelligence Design tactics Review and perspective

A Selenium Atom Involved Covalent Organic Framework for Window Ledge Photocatalytic Oxidation of Sulfides

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第17期42卷 1960-1966页

作者： fan Yang Xia li {2.-Yan Qu Jing-Lan Kan Yuan Guo Yu-bin Dong College of Chemistry Chemical Engineering and Materials ScienceCollaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongKey Laboratory of Molecular and Nano ProbesMinistry of EducationShandong Normal UniversityJinanShandong250014China school of light Industry and Engineering Qilu University of Technology(Shandong Academy of Sciences)JinanShandong 250353China

Covalent organic frameworks(coFs)driven photocatalytic organic transformations especially photooxidation reactions have become a fertile topic and attracted numerous research *** the charge generation and transport process is the key factor for achieving high catalytic *** one of the most effective strategies,the introduction of"heavy atoms"into the long-range ordered conjugated backbones can effectively facilitate the intersystem crossing(isc)process and hence improve the generation of active oxygens,which is beneficial for the *** this work,we designed and synthesized a benzoselenadiazole based covalent organic framework(COF)material,BSe-COF with heavy atom of selenium(Se),and a benzothiadiazole based BT-COF with isomorphic backbone for comparison.

关键词： Covalent organic framework Benzoselenadiazole Density functional theory Heavy atom Photocatalysis Photooxidation Singletoxygen Window ledge reaction

Role of Exosomal Modulation of Macrophages in liver Fibrosis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Clinical and Translational Hepatology 2024年第2期12卷 201-209页

作者： bin fan He Xie {2. Tan {2.ngyuan li Tao Gong Baoren He Yujia li limin Chen Institute of Blood Transfusion(IBT) Chinese Academy of Medical Sciences(CAMS)and Peking Union Medical College(PUMC)ChengduSichuanChina The Hospital of Xidian Group Xi’anShaanxiChina Department of Clinical Medicine North Sichuan Medical CollegeNanchongSichuanChina The Joint Laboratory of Transfusion-Transmitted Diseases(TTDs)between Institute of Blood Transfusion(IBT) Chinese Academy of Medical Sciences(CAMS)and Nanning Blood CenterNanningGuangxiChina

Exosomes are 60–12. nm diameter double-membrane lipid organelles discharged by *** studies have shown that exosomes exert multiple functions in both physical and diseased processes,such as intercellular information exchange,immune response,and disease *** chronic injury to the liver often leads to inflammation and liver fibrosis(LF),a disorder that,if unchecked,may progress to cirrhosis,liver failure,portal hypertension,and even hepatocellular *** an essential component of host innate immunity against pathogen invasion,macrophages play an important role in modulating inflammation homeostasis by finely tuning the polarization process of macrophages into either M1 or M2.subtypes in response to different *** a critical contributor to the inflammation process,macrophages also play a complex and instrumental function in the progression of *** review focuses on recent advancements in the role of macrophage-associated exosomes implicated in LF,including macrophage-released exosomes and macrophage-targeted *** addition,the progress made in exosomebased antifibrotic therapy by in vivo and in vitro studies is also highlighted.

关键词： Exosome Macrophage liver fibrosis Hepatocyte Mesenchymal stem cell Hepatic stellate cell

Crystallization of RE_(2.(OH)_(2.CO_(3)SO_(4)·nH_(2.O as a new family of layered hydroxides(RE=Gd-Lu lanthanides and Y),derivation of RE_(2.O_(2.SO_(4),photoluminescence and optical thermometry

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第8期42卷 1496-1506,I0003页

作者： fan li Zhen{2. Song Zhiyuan Pan Sihan Feng {2. Zhu Ji-Guang li Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Research Center for Functional Materials National Institute for Materials ScienceTSsukuboaIbaraki3050044Japan

Layered rare-earth hydroxides(LREHs) draw wide research interest because of their peculiar crystal structure,rich interlayer chemistry and abundant functionality of the RE element,but are limited to the two categories of RE_(2.(OH)_(5)A·nH_(2.O(A:typical of Cl^(-)or NO_(3)^(-)) and RE_(2.(OH)_(4)SO_(4)·nH_(2.*** the other hand,rare-earth oxysulfates(RE_(2.O_(2.SO_(4)) have attracted attention due to their properties of large-capacity oxygen storage,low-temperature magnetism and luminescence,but their preparation procedure mostly involves toxic SO_(x) gases and/or complicated *** this work,RE_(2.(OH)_(2.CO_(3)SO_(4)·nH_(2.O as a new family of LREHs(RE=Gd-Lu lanthanides and Y) were produced via hydrothermal reaction,from which phase-pure RE_(2.O_(2.SO_(4) was derived via subsequent annealing at 800℃ in air without the involvement of SO_(x),The compounds were thoroughly characterized to reveal the intrinsic influence of lanthanide contraction(RE^(3+) radius) on crystal structure,thermal behavior(dehydroxylation/decarbonation/desulfurization),vibrational property and crystallite *** analyzing the photoluminescence of Eu^(3+) and Sm^(3+)in the Gd_(2.O_(2.SO_(4) typical host it is found that the 617 nm(Eu^(3+),λ_(ex)=2.5 nm) and 608 nm(Sm^(3+),λ_(ex)=407 nm) main emissions can retain as high as ^(7)9.6% and 85.5%of their room-temperature intensities at 42. K,with activation energies of ~0.19 and 0.2. eV for thermal quenching,*** also indicates that both the phosphors have the potential for optical temperature sensing via the fluorescence intensity ratio(FIR) technology,whose maximum relative sensitivity reaches -2.70%/K for Eu^(3+)and 1.73%/K for Sm^(3+) at 2.8 K.

关键词： Layered hydroxide RE_(2.O_(2.SO_(4) Luminescence Optical temperature sensing Rare earths

High-performance broadband photodetector based on PtSe2.MoS2.heterojunction from visible to near-infrared region

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2024年第3期67卷 263-270页

作者： bin WANG Jian YUAN Mengqi CHE Mingxiu {2.U Yuting ZOU Junru AN fan TAN Yaru SHI Nan ZHANG {2.ujian qi Shaojuan {2. State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences school of Physics and Electronic Information Huaibei Normal University

Broadband photodetectors based on narrow bandgap 2. materials have garnered considerable interest for application in the field of optoelectronic devices. However, their large dark current hinders device performance. In this work, a PtSe2.MoS2.eterojunction was fabricated for a broadband photodetector operating within the range of visible to near-infrared. The device exhibited suppressed dark currents with a high rectification ratio of 104. The built-in electric field of the heterojunction promoted carrier separation effectively, and the device achieved excellent photoelectric performance with responsivities of 1.7 × 103,2..52. and 2. mA/W at 635, 785, and 1550 nm wavelengths, respectively. Moreover, the specific detectivities(D*) were 2.2.× 1013Jones(635 nm), 3.55 × 1011Jones(785 nm), and 2.72.× 108Jones(1550 nm). The device demonstrated a rise/fall time of 131/2.1.μs under 1550 nm laser illumination. Visible and near-infrared imaging detection was also demonstrated based on the heterojunction device at room temperature. This work sheds light on the remarkable potential of PtSe2.MoS2.eterojunctions in the domain of high-performance broadband photodetectors.

关键词： photodetector PtSe$_{2.$/MoS$_{2.$ heterojunction visible to near infrared high performance