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基于计算流体力学-离散元耦合的相对密实度对断级配土体渗蚀效应的影响研究

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岩土力学 2024年第1期45卷 267-283页

作者：张沛云木林隆黄茂松同济大学岩土及地下工程教育部重点实验室上海200092 同济大学地下建筑与工程系上海200092

土体几何因素(粒径比、细粒含量、相对密实度等)不仅影响土体内部稳定性,同时对侵蚀进程有着重要影响。基于离散单元法(discrete element method,简称DEM)与计算流体动力学(computational fluid dynamics,简称CFD)耦合方法,建立了内部... 详细信息

土体几何因素(粒径比、细粒含量、相对密实度等)不仅影响土体内部稳定性,同时对侵蚀进程有着重要影响。基于离散单元法(discrete element method,简称DEM)与计算流体动力学(computational fluid dynamics,简称CFD)耦合方法,建立了内部不稳定土渗流-侵蚀三维计算模型。考虑细粒含量及相对密实度对内部侵蚀过程的耦合影响,对细观变量:土体孔径分布曲线、颗粒接触数目以及内部传力机制进行分析,以揭示细粒含量与相对密实度的影响的细观机制。研究结果表明:相对密实度的增加降低了侵蚀质量比,且该影响程度与细粒含量相关,细粒含量越高,相对密实度的影响更加明显;内部不稳定土体渗蚀后沿渗流方向可分为上游侵蚀区、中部稳定区及下游侵蚀区。土体渗透性在侵蚀过程中的增长幅度随相对密实度的降低而逐渐增加,随细粒含量的增加而增加;相对密实度对渗蚀过程的影响可归因于三方面:相同水力梯度下渗流流量不同,内部孔隙尺寸分布存在差异,以及细颗粒对土体内部应力传递的贡献不同。研究结果加深了土体几何因素对内部渗蚀过程影响的理解,并为宏观侵蚀本构的建立提供了参考。

关键词：渗蚀 CFD-DEM 相对密实度细粒含量传力机制

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Preparation and characterization of high-reactivity explosive-based nano-boron microspheres

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PARTICUOLOGY 2024年第10期93卷 125-136页

作者： Dong, Chen Wang, Yi Jia, Kanghui song, Dan song, Xiaolan An, Chongwei North Univ China Sch Mat Sci & Engn Taiyuan 030051 Peoples R China Jinxi Grp Shanxi Jiangyang Chem Co Ltd Taiyuan 030051 Peoples R China China Ordnance Inst Sci & Technol Beijing 100089 Peoples R China North Univ China Sch Environm & Safety Engn Taiyuan 030051 Peoples R China

Boron nanoparticles, with their remarkably high gravimetric and volumetric calorific values, emerge as the most promising fuel in energetic fields. However, challenges such as susceptibility to oxidation, high ignition temperature, and low combustion efficiency have constrained their further applications. In this study, we fabricated high explosives based nano-boron microspheres with uniform size using the electrostatic spray method, in which the boron nanoparticles and high explosives (CL-20 or PETN) are closely bonded together by fluorinated polymer (F-2602) and evenly distributed. The results indicated that the microspheres exhibited high sphericity and showed an enhanced antioxidant capability. The addition of high-energy explosives not only reduced the thermal oxidation temperature of nano-boron powder within the microspheres but also significantly enhanced the pressurization rate. Additionally, the microspheres with added high-energy explosives released more energy during the combustion process. Compared to physically mixed samples, electrostatically sprayed microspheres with a uniform microstructure still exhibited higher reactivity. Therefore, the design and synthesis of microspheres with controllable structures using the electrostatic spray method show promising application prospects. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Nano-boron CL-20 PETN Electrospraying Ignition and combustion NANOPARTICLES COMBUSTION

Optimizing multi-parameter distributed fiber sensors:a hybrid Rayleigh-Brillouin-Raman System approach

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Light(Science & Applications) 2024年第3期13卷 393-395页

作者： Kwang Yong song Dept.of Physics Chung-Ang University84 Heukseok-roDongjak-guSeoul 06974Korea

An optimized single-end hybrid Rayleigh,Brillouin,and Raman distributed fiber sensing system has been developed for simultaneous measurement of multiple *** system integrates 3-bit pulse coding for the Raman signal and the Brillouin amplification of the Rayleigh-backscattered signal,discriminating strain,temperature,and vibration using a single sensing fiber.

关键词： fiber Rayleigh signal

Berry-Esseen bounds for self-normalized sums of locally dependent random variables

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Science China Mathematics 2024年第11期67卷 2629-2652页

作者： Zhuo-song Zhang Department of Statistics and Data Science Southern University of Science and Technology

The Berry-Esseen bound provides an upper bound on the Kolmogorov distance between a random variable and the normal *** this paper,we establish Berry-Esseen bounds with optimal rates for self-normalized sums of locally dependent random variables,assuming only a second-moment *** proof leverages Stein's method and introduces a novel randomized concentration inequality,which may also be of independent interest for other *** main results have applied to self-normalized sums of m-dependent random variables and graph dependency models.

关键词： Berry-Esseen bounds self-normalized sums localdependence $m$-dependence graph dependency

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Effect of nano-carbon black content on wetting phenomenon of molten steel and alumina-carbon ceramic filter substrates

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Journal of Iron and Steel Research International 2024年第8期31卷 1900-1913页

作者： Jin-wen song Wen Yan Zhe Chen Ying Liu Shao-song Hong The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina National-provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology Wuhan University of Science and TechnologyWuhan 430081HubeiChina Jiangsu Sheng Nai New Materials Co. Ltd.Taizhou 225503JiangsuChina

The effect of nano-carbon black content(O,8 and 12 wt.%)on the wettability of molten steel on Al_(2)O_(3)-C substrates was investigated by the sessile drop wetting method at 1500℃ under argon *** the beginning of the wetting experiment,the contact angle decreased with the increase in nano-carbon black *** the wetting experiment progressed,FeAl_(2)0_(4) layer and sheet Al_(2)O_(3) layer were found at the interface between the molten steel and the Al_(2)O_(3)-C substrates with O and 8 wt.% nano-carbon black content,and the contact angle deceased with *** the content of nano-carbon black was 12 wt.%,a large number of nano-Al_(2)O_(3) whiskers were observed,which made the contact angle between the molten steel and Al_(2)O_(3)-C substrate become *** on the scanning electron microscope and energy dispersive spectrometry results,the formation mechanism of FeAl2O4 layer and Al_(2)O_(3) layer and the interfacial reaction mechanism were proposed.

关键词： Contact angle Nano-carbon black Al_(2)O_(3)-C substrate Molten steel Interfacial reaction

Spiking neural networks in intelligent control systems:a perspective

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Science China(Information Sciences) 2024年第7期67卷 324-326页

作者： Anguo ZHANG Yongduan song School of Artificial Intelligence Anhui University School of Automation Chongqing University

Artificial intelligence (AI) has undergone substantial advancements in recent years, prompting an era of innovation in various domains. Among the groundbreaking contributions, neural networks stand at the forefront, powering applications ranging from computer vision and natural language processing to intelligent control systems [1, 2].

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Genome-wide SNP markers provided insights into the reproductive strategy and genetic diversity of the green tide causative species Ulva prolifera in China

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Journal of Oceanology and Limnology 2024年第2期42卷 533-543页

作者： song SUN Weiwei MA Nan WANG song FENG Yan SUN CAS Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Ecology and Environmental Science Laoshan LaboratoryQingdao 266237China Jiaozhou Bay Marine Ecosystem Research Station Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China

Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since *** specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green *** the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to *** genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating ***,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different *** results showed the efficiency of 2b-RAD in the exploration of SNPs in *** and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao *** study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China.

关键词： green tide Ulva prolifera 2b-RAD single-nucleotide polymorphism(SNP) reproductive strategy genetic diversity

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Detection of a reassortant swine H1N2 influenza A virus from pigs in Hong Kong

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Virologica Sinica 2024年第2期39卷 343-346页

作者： Guoqian Gu Congnuan Liu song Hao Lee Lewis Sze Chun Choi Michael T.Wilson Dirk U.Pfeiffer yun Young Go Department of Infectious Diseases and Public Health Jockey Club College of Veterinary Medicine and Life SciencesCity University of Hong KongHong Kong SARChina Center for Applied One Health Research and Policy Advice Jockey Club College of Veterinary Medicine and Life SciencesCity University of Hong KongHong Kong SARChina College of Veterinary Medicine Konkuk UniversitySeoul143-701Republic of Korea

Dear Editor,Influenza A viruses(IAVs)are responsible for significant respiratory illnesses in humans and a broad range of animal *** outbreaks and the rapid spread of genetically and antigenically distinct IAVs represent a considerable challenge for swine *** are susceptible to avian and human IAV infections and are considered“mixing vessels”where human,avian,and swine IAVs can recombine and generate novel reassortant influenza viruses with pandemic potential(Vincent et al.,2014).

关键词： swine influenza mixing

Experimental study on combustion characteristics of supersonic combustor based on alternating-wedge strut

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Chinese Journal of Aeronautics 2024年第5期37卷 214-227页

作者： Jie LI Wenyan song Yuhang WANG School of Power Energy Northwestern Polytechnical UniversityXi’an 710129China

Acetone Planar Lase-Induced Fluorescence(PLIF)and OH-PLIF were employed to capture the fuel distribution and OH distribution downstream for the supersonic combustor based on the alternating-wedge *** combustion establishment process and combustion mode in the combustor under different fuel injection methods and different equivalence ratios were *** with the kerosene-PLIF and OH-PLIF results in the cavity combustor,a comparative analysis was conducted to understand the combustion characteristics and combustion modes between the alternating-wedge strut-based combustor and the cavity-based *** results show that the combustor is in weak combustion mode in the case of low equivalence ratio,and the combustor is in intensive combustion mode in the case of high equivalence *** lower limit of the equivalence ratio of the combustor to maintain the intensive combustion mode varies based on different fuel injection *** OH distribution under reacting condition has a strong correlation with the fuel distribution under non-reacting *** OH fluorescence signal near the injector is weaker when the fuel distribution is more *** injector position located at the base of the strut rear has better mixing performance,enabling the combustor to be in intensive combustion mode at a lower equivalence *** combustion reaction in the alternating-wedge strut-based combustor is not necessarily dominated by mass transfer due to the mixing enhancement and premixed zone downstream of strut,while the combustion reaction process in the cavity-based combustor is mainly influenced by mass transfer.

关键词： Supersonic combustor Alternating-wedge strut Cavity PLIF Fuel injection Fuel distribution Combustion characteristics Combustion mode

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