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Local resistance characteristics of elbows for supercritical pressure RP-3 flowing in serpentine micro-tubes

Propulsion and Power Research 2024年第2期13卷 245-256页

作者： Yanchen Fu yinlong liu Juan Wang Yu Wang Guoqiang Xu Jie Wen Research Institute of Aero-engine Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijing 100191China Zhongfa Aviation Institute of Beihang University Hangzhou 310023China AECC Sichuan Gas Turbine Research Institute Chengdu 610500China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China School of Energy and Power Engineering Beihang UniversityBeijing 100191China

Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection on aero-engines,the elbow localﬂow resistance charac-teristics for supercritical pressure aviation fuel RP-3ﬂowing in adiabatic horizontal serpentine tubes with the inner diameter of 1.8 mm and the massﬂux of 1179 kg/(m^(2)·s)were experimen-tally *** long-short-tube method was used to obtain the elbow pressure drop from the total serpentine tube pressure drop,and the effects of system pressures(P/Pc=1.72-2.58)and geometry parameters including bend numbers(n=5-11),bend diameters(D/d=16.7-27.8),and bend distances(L/d=20-60)on elbow pressure drops and local resistance co-efﬁcients are analyzed on the basis of the thermal physical property *** results show that both the increase in the elbow pressure drop and the decrease in the local resistance coef-ﬁcient with temperatures speed up at the near pseudo-critical temperature region of T>*** the growth of the elbow local pressure drop could be inhibited by the increase of system pressures,while the local resistance coefﬁcient is slightly affected by *** inﬂuence of bend diameters on the local resistance coefﬁcient is mild when D/d is larger than 22.2 in the premise of fully developedﬂow in straight ***,a piecewise empir-ical correlation considering the bend diameter and physical property ratio is developed to pre-dict the elbow pressure drop of the serpentine tube and optimize the layout of the cooling tube system on aero-engines.

关键词： Supercritical pressure Aviation fuel Local resistance coefﬁcient Elbow Serpentine tube Empirical correlation

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基于博弈论的入侵检测与响应优化综述

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信息安全学报 2024年第4期9卷 163-179页

作者：张杭生刘吉强梁杰刘海涛李婷耿立茹刘银龙中国科学院信息工程研究所北京100093 中国科学院大学网络空间安全学院北京100049 北京交通大学智能交通数据安全与隐私保护北京市重点实验室北京100044

当前网络规模急剧增加,各类入侵过程也逐渐向复杂化、多样化的趋势发展。网络攻击带来的损失越来越严重,针对各类安全事件的检测发现以及查处响应也变得日益困难。为了快速识别各类网络安全事件并做出相应的响应,入侵检测与响应技术变... 详细信息

当前网络规模急剧增加,各类入侵过程也逐渐向复杂化、多样化的趋势发展。网络攻击带来的损失越来越严重,针对各类安全事件的检测发现以及查处响应也变得日益困难。为了快速识别各类网络安全事件并做出相应的响应,入侵检测与响应技术变得越来越重要。入侵检测系统(IDS)能否识别复杂的攻击模式以及分析大量的网络流量主要取决于其精度和配置,这使得入侵检测与响应的优化问题成为网络与系统安全的重要需求,并且成为一个活跃的研究主题。现有的研究成果已经提出了很多可以优化入侵检测和响应效率的方法,其中,将博弈论应用在入侵检测与响应的研究日益增多。博弈论提供了一种框架去捕获攻击者和防御者的交互,采用了一种定量的方法评估系统的安全性。本文在分析了入侵检测与响应系统和博弈论的基本原理的基础上,介绍了当前基于博弈论的入侵检测与响应优化问题的现有解决方案,并且讨论了这些解决方案的局限性以及给出了未来的研究方向。首先,详细介绍了入侵检测与博弈论的背景知识,回顾了常用的入侵检测系统基本原理,评估方法,常用的数据集以及经典的安全领域中的博弈论模型。其次,按照基于博弈论的入侵检测与响应优化问题的类型进行了分类介绍,根据攻击的先后顺序对网络安全架构优化、IDS配置与效率优化、IDS的自动化响应优化以及分布式入侵检测架构优化等技术的研究现状进行归纳、分析、总结,并分析了现有方案的优缺点,进而分析可能的解决方案。然后针对将博弈论应用于入侵检测与响应中面临的挑战进行了分析与讨论。最后展望了未来的研究方向以及发展趋势。

关键词：博弈论入侵检测入侵响应多智能体强化学习网络安全

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刑事案件诉源治理视角下检察建议研究

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山西警察学院学报 2024年第5期32卷 86-93页

作者：李蕾刘银龙张亚露长治市人民检察院山西长治046000 长治学院山西长治046011

刑事案件诉源治理对预防犯罪和提升社会治理效能具有重要意义。检察建议具备的治理功能、预防功能和保护功能是促进社会治理的优势所在,这些功能的发挥能有效促进刑事案件的诉源治理。检视检察建议的运行实践发现,检察机关及其工作人员... 详细信息

刑事案件诉源治理对预防犯罪和提升社会治理效能具有重要意义。检察建议具备的治理功能、预防功能和保护功能是促进社会治理的优势所在,这些功能的发挥能有效促进刑事案件的诉源治理。检视检察建议的运行实践发现,检察机关及其工作人员主动提出检察建议的意识不强,检察建议文书质量不高,检察建议的落实效果不佳。为此,要推进检察机关依法能动履职,培育检察建议意识;严把检察建议关口,提升检察建议质量,不断增强检察建议的影响力;借鉴各地先进做法,用好检察建议的跟踪回访机制,适时把检察建议工作纳入法治建设考核范围,确保检察建议发挥实效。

关键词：诉源治理刑事案件检察建议

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Towards Qo E-based resource allocation schemes in SC-FDMA systems

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The Journal of China Universities of Posts and Telecommunications 2015年第5期22卷 63-70 100,100页

作者： Hu Yahui liu yinlong Zhou Xu Xu Zhen Institute of Information Engineering Chinese Academy of Science

One of the critical techniques of quality of experience(Qo E) provisioning in single carrier frequency division multiple access(SC-FDMA) systems is related to implementation of efficient radio resource allocation(RRA) schemes. So far as we know, Qo E-based RRA in SC-FDMA systems is still an open issue. Therefore, in this paper, five different Qo E-based RRA schemes in SC-FDMA system are investigated based on different criteria. The first three Qo E criteria applied in other wireless systems are maximizing average mean opinion score(MOS) over all users(Max-MOS), maximizing the minimum MOS among all users(Max Min-MOS) and maximizing the minimum MOS with dropping some users requiring the highest amount of resources(Max Min-Min MOSX.Y-MOS). Then, the improved Max Min-Min MOSX.Y-MOS criterion focuses on changing user dropping principle to promote the probability of more users obtaining satisfied experience. By defining MOS higher than threshold as the effective MOS, maximizing average effective MOS over all users(Max-EMOS) is proposed as a totally new criterion which gives quantitative measurement of how many users to what extent obtaining satisfied experience. Mathematical expressions and solutions of these schemes are also presented in this paper. In addition, performance comparisons are made in simulations to further display their respective advantages and disadvantages.

关键词： single carrier frequency division multiple access(

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Airside pressure drop characteristics of three analogous serpentine tube heat exchangers considering heat transfer for aero-engine cooling

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Chinese Journal of Aeronautics 2022年第12期35卷 32-46页

作者： yinlong liu Guoqiang XU Yanchen FU Jie WEN Shaoshuai QI Lulu LYU Research Institute of Aero-engine Beihang UniversityBeijing 100083China National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics Beihang UniversityBeijing 100083China School of Energy and Power Engineering Beihang UniversityBeijing 100083China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China China Aerospace Aerodynamics Technology Research Institute Beijing 100074China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 200241China

This study explores the design,analysis,and air pressure drop assessment of three analogous air–fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number *** high speed flight,the compressor bleed air used to cool high temperature turbine blades and other hot components is too ***,aviation kerosene is applied to precool the compressor bleed air by means of novel air–fuel heat *** light and compact heat exchangers including dozens of in-line thin serpentine tube bundles were designed and manufactured,with little difference existing in aspects of tube pitches and outer diameters among three heat *** fuel flows inside a series of parallel stainless serpentine tubes(outer diameter:2.2,1.8,1.4 mm with 0.2 mm thickness),while the air externally flows normal to tube bundles and countercurrent with *** studies were carried out to investigate the airside pressure drop characteristics on isothermal states with the variation of air mass flow rates and inlet ***-isothermal measurements have also been performed to research the effect of heat transfer on pressure *** experimental results show that inlet temperatures have significant influence on pressure drops,and higher temperatures lead to higher pressure drops at the same mass flow *** hydraulic resistance coefficient decreases quickly with Reynolds number,and the descent rate slows down when Re>6000 for all three heat ***,the pressure drop on heat transfer states is less than that on isothermal states for the same average ***,the pressure drop through heat exchangers is greatly affected by attack angles and transverse pitches,and an asymmetric M-shaped velocity profile is generated in the crosssection of sector channels.

关键词： Aero-engine Heat exchanger Heat transfer Pressure drop Serpentine tube

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Frictional resistance of supercritical pressure RP-3 flowing in a vertically downward tube at constant heat fluxes

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Chinese Journal of Aeronautics 2022年第9期35卷 117-128页

作者： yinlong liu Guoqiang XU Yanchen FU Jie WEN Geng GONG Lulu LYU Research Institute of Aero-engine Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China China Aerodynamics Research and Development Center Mianyang 621000China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 200241China

Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection, the flow resistance characteristics of aviation kerosene RP-3 were experimentally studied in a vertically downward circular miniature tube with an inner diameter of 1.86 mm at supercritical pressures and constant heat fluxes. A long and short tube method was used to accurately calculate the frictional pressure drop, and experimental conditions are supercritical pressures of 4 MPa, mass flow rates of 2–4 g/s(i.e., mass fluxes of 736–1472 kg/(m^(2)·s)), heat fluxes of 100–500 kW/m^(2), and inlet temperatures of 373–673 K. Results show that the sharp variations of thermophysical properties, especially density, have significant influences on frictional ***, the frictional pressure drop and the friction factor increase with increasing inlet temperatures, and this trend speeds up in the relatively high-temperature region. However, the friction factor has a sudden decline when the fuel outlet temperature exceeds the pseudo-critical *** frictional pressure drop and the friction factor basically remain unchanged with increasing heat flux when the inlet temperature is relatively low, but increase quickly when the inlet temperature is relatively high. Besides, a larger mass flux yields a higher pressure drop but does not necessarily yield a higher friction factor. Finally, an empirical friction factor correlation is proposed and shows better predictive performance than those of previous models.

关键词： Aviation kerosene RP-3 Constant heat flux Empirical correlation Friction factor Supercritical pressure Vertical tube

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Study of the Transient Reactive Pd(Ⅳ) Intermediate in the Pd(OAc)2-Catalyzed Oxidative Coupling Reaction System by Electrospray Ionization Tandem Mass Spectrometry

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Chinese Journal of Chemistry 2013年第3期31卷 371-376页

作者： Wei Zhu Haoyang Wang Haihui Peng Guosheng liu yinlong Guo Shanghai Mass Spectrometry Center Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C--H activation and the for-mation of new C-O and C--C bonds. Sanford has pioneered practical, directed C-H activation reactions em-ploying Pd（OAc）2 as catalyst since 2004. However, until now, the speculated reactive Pd（Ⅳ） transient intermedi-ates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry （ESI-MS/MS） was used to intercept and characterize the reactive Pd（Ⅳ） transient inter-mediates in the solutions of Pd（OAc）2-catalyzed oxidative coupling reactions. In this study, the Pd（IV） transient in-termediates were detected from the solution of Pd（OAc）2-catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd（IV） transient intermediate in reaction system was the same with the synthesized au-thentic Pd（Ⅳ） complex. Our ESI-MS（/MS） studies confirmed the presence of Pd（Ⅳ） reaction transient intermedi-ates. Most interestingly, the MS/MS of Pd（Ⅳ） transient intermediates showed the reductive elimination reactivity to Pd（Ⅱ） complexes with new C-O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd（Ⅳ） transient intermediates in solution.

关键词： electrospray ionization tandem mass spectrometry (ESI-MS/MS) Pd(IV) transient intermediate oxi^dative coupling reaction

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支持移动AIGC业务的边缘算力网络技术与安全性分析

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信息通信技术 2024年第3期18卷 19-26页

作者：刘银龙程新洲庄尚缘孙继燕中国科学院信息工程研究所北京100085 中国科学院大学网络空间安全学院北京100049 中国联通研究院北京100176

随着泛在分布的移动终端逐步具备搭载人工智能生成内容(AIGC)应用的能力,移动AIGC业务将迎来快速增长。这一趋势使得当前依赖算力中心集中处理AIGC业务请求的计算范式出现明显不足,因此亟须探索能够满足泛在AIGC业务需求的新型算力供给... 详细信息

随着泛在分布的移动终端逐步具备搭载人工智能生成内容(AIGC)应用的能力,移动AIGC业务将迎来快速增长。这一趋势使得当前依赖算力中心集中处理AIGC业务请求的计算范式出现明显不足,因此亟须探索能够满足泛在AIGC业务需求的新型算力供给方式。边缘算力网络可以在靠近用户处更快、更灵活地执行推理,并有效分散算力中心的计算压力。为此,文章探讨边缘算力网络给AIGC业务大规模应用带来的新机遇,并梳理其架构、技术优势与技术挑战。同时,注意到边缘算力节点天然的物理可接近性与弱防护特性,文章重点分析边缘算力网络给AIGC技术引入的安全挑战,旨在为未来AIGC技术的研究与应用提供新的视角。

关键词：人工智能生成内容边缘算力模型安全数据安全

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帕金森病患者颈部迷走神经横截面面积与心血管自主神经功能障碍的关系

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中华实用诊断与治疗杂志 2024年第1期38卷 52-56页

作者：陈思远刘银龙古祺吴少璞马建军李学郑州大学人民医院河南省人民医院神经内科河南郑州450003 郑州大学人民医院河南省人民医院超声科河南郑州450003

目的观察帕金森病(PD)患者颈部迷走神经横截面面积(CAS)变化,探讨其与心血管自主神经功能障碍的关系。方法 2019年10月—2022年10月河南省人民医院诊治PD患者45例为PD组,记录PD患者入院时帕金森病评定量表Ⅲ(UPDRS-Ⅲ)评分、Hoehn-Yahr... 详细信息

目的观察帕金森病(PD)患者颈部迷走神经横截面面积(CAS)变化,探讨其与心血管自主神经功能障碍的关系。方法 2019年10月—2022年10月河南省人民医院诊治PD患者45例为PD组,记录PD患者入院时帕金森病评定量表Ⅲ(UPDRS-Ⅲ)评分、Hoehn-Yahr(H-Y)分级。同期体检健康者45例为对照组。PD组于入院日、对照组于体检日采用PD自主神经症状量表(SCOPA-AUT)评估自主神经功能,记录SCOPA-AUT心血管评分;行颈部超声检查,测量左右侧颈部迷走神经CAS;行24 h动态心电图检查分析心率变异率,记录全部正常R-R间期标准差(SDNN)、全部相邻R-R间期差值的均方根(rMSSD)、高频功率(HF)、低频功率(LF)。比较2组性别、年龄、体质量指数、SCOPA-AUT总分、SCOPA-AUT心血管评分、颈部迷走神经CAS及SDNN、rMSSD、HF、LF;Pearson相关法分析PD患者左右侧颈部迷走神经CAS与PD病程、UPDRS-Ⅲ评分、H-Y分级、SCOPA-AUT评分、SCOPA-AUT心血管评分的相关性,右侧颈部迷走神经CAS与SDNN、rMSSD、HF、LF的相关性。结果 (1)PD组性别比例、年龄、体质量指数与对照组比较差异均无统计学意义(P>0.05)。PD组SCOPA-AUT总分[(16.22±5.21)分]、SCOPA-AUT心血管评分[(3.40±1.68)分]均高于对照组[(3.12±1.78)、(1.05±0.77)分](t=15.147,P0.05)。(4)PD患者UPDRS-Ⅲ评分为(26.19±14.53)分、H-Y分级为(2.51±0.78)级。PD患者右侧颈部迷走神经CAS与H-Y分级(r=-0.343,P=0.023)、SCOPA-AUT总分(r=-0.415,P=0.006)、SCOPA-AUT心血管评分(r=-0.448,P=0.002)均呈负相关,与rMSSD(r=0.318,P=0.040)、HF(r=0.409,P=0.006)均呈正相关。结论 PD患者双侧迷走神经CAS缩小,右侧迷走神经CAS越小心血管自主神经功能受损越重,右侧迷走神经CAS可作为量化PD患者心血管自主功能障碍的指标。

关键词：帕金森病颈部迷走神经横截面面积自主神经功能障碍心率变异率

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Orbital angular momentum conversion of acoustic vortex beams via planar lattice coupling

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Chinese Physics B 2024年第9期33卷 413-420页

作者： Qingbang Han Zhipeng liu Cheng Yin Simeng Wu yinlong Luo Zixin Yang Xiuyang Pang Yiqiu Wang Xuefen Kan Yuqiu Zhang Qiang Yu Jian Wu College of Information Science and Engineering Hohai UniversityChangzhou 213200China College of Advanced Interdisciplinary Studies Nanhu Laser LaboratoryNational University ofDefense TechnologyChangsha 410073China School of Transportation Engineering Jiangsu Shipping CollegeNantong 226010China i-Lab Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou215123China

Orbital angular momentum(OAM)conversion is critical in understanding interactions between a structural sound field and a planar ***,we explore the evolution of a monochromatic acoustic vortex beam(AVB)that is scattered by a phononic crystal(PnC)or a correlated random *** phenomenon is ascribed to the enhanced orbit–orbit angular momentum coupling induced by the band *** modifying the coupling condition,accurate and continuous micromanipulation of AVBs can be achieved,including the transverse/lateral gravity shift,the dynamics of the phase singularities,and the spatial distribution of acoustic pressure,*** research provides insight to the inhomogeneous coupling of AVBs with both propagating Bloch waves and localized Anderson modes,and may facilitate development of novel OAM-based acoustic devices for active sound field manipulation.

关键词： acoustic vortex beam phononic crystal Anderson localization Imbert–Fedorov effect

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