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Defence Technology（防务技术） 2024年第1期31卷 230-241页

作者： junbao li Weibing li Xiaoming Wang ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing 210094China

This study proposed three types of Al—Hf reactive materials with particle size ratios(a),which were almost completely dense(porosity of<5.40%)owing to their preparation using hot-pressing *** characteristics and phas... 详细信息

This study proposed three types of Al—Hf reactive materials with particle size ratios(a),which were almost completely dense(porosity oflinearly with increasing strain rate.ε.It is found that the plastic deformation of the material increased with increasing strain *** a increased from 0.1 to 1,the flow stress gradually *** failure of the material was dominated by ductile fracture with a large Al phase plastic deformation band for lower a,while brittle fracture with crushed Hf particles occurred at higher ***,a constitutive model based on BP neural network was proposed to describe the stress-strain relationships of the materials,with an average relative error of 2.22%.

关键词： Reactive material Particle size Split Hopkinson pressure bar test Stressestrain relationship Impact failure BP neural network

Crack propagation and damage evolution of metallic cylindrical shells under internal explosive loading

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Defence Technology（防务技术） 2024年第9期39卷 133-146页

作者： Yusong Luo Weibing li junbao li Wenbin li Xiaoming Wang ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing210094China

This paper investigates the three-dimensional crack propagation and damage evolution process of metallic column shells under internal explosive *** calibration of four typical failure parameters for 40CrMnSiB steel was conducted through experiments and subsequently applied to *** numerical simulation results employing the four failure criteria were compared with the differences and similarities observed in freeze-recovery tests and ultra-high-speed *** analysis addressed the critical issue of determining failure criteria for the fracture of a metal shell under internal explosive *** upon this foundation,the damage parameter D_(c),linked to the cumulative crack density,was defined based on the evolution characteristics of a substantial number of *** relationship between the damage parameter and crack velocity over time was established,and the influence of the internal central pressure on the damage parameter and crack velocity was *** in the fracture modes were found under different failure criteria,with the principal strain failure criterion proving to be the most effective for simulating 3D crack propagation in a pure shear fracture *** statistical analysis of the shell penetration fracture radius data,it was determined that the fracture radius remained essentially constant during the crack evolution process and could be considered a *** propagation velocity of axial cracks ranged between 5300 m/s and 12600 m/s,surpassing the Rayleigh wave velocity of the shell material and decreasing linearly with *** increase in shell damage exhibited an initial rapid phase,followed by deceleration,demonstrating accelerated damage during the propagation stage of the blast wave and decelerated damage after the arrival of the rarefaction *** study provides an effective approach for investigating crack propagation and damage *** derived crack propagation and damage evolution law s

关键词： Internal explosive loading Failure criterion Crack propagation Damage evolution Freeze-recovery test

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基于5G通信技术的实时照明控制系统设计

中国照明电器 2024年第8期 98-100,111页

作者：李军保合肥经济学院人工智能学院安徽合肥230031

随着智能建筑和智慧城市概念的推广,在实时照明控制系统中引入5G通信技术,有利于实现智能、高效的照明控制,提高照明效率。因此,本文探讨基于5G通信技术的实时照明控制系统设计,以期为照明领域提供理论参考。

关键词： 5G通信技术实时照明照明控制系统

维普期刊数据库博看期刊

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含调整器装药结构破片形成影响因素研究

南京理工大学学报 2024年第3期48卷 262-270页

作者：任冠群李伟兵徐赫阳李文彬李军宝南京理工大学智能弹药技术国防重点学科实验室江苏南京210094 上海航天电子技术研究所上海201109

为有效改善柱壳断裂位置并产生形状规则的大质量破片,该文设计了一种由柱壳装药以及嵌入其中的爆轰波调整器构成的新型破片战斗部结构,并研究了爆轰波调整器结构参数对破片输出的影响。采用AUTODYN-3D有限元计算软件,分析了爆轰波碰撞... 详细信息

为有效改善柱壳断裂位置并产生形状规则的大质量破片,该文设计了一种由柱壳装药以及嵌入其中的爆轰波调整器构成的新型破片战斗部结构,并研究了爆轰波调整器结构参数对破片输出的影响。采用AUTODYN-3D有限元计算软件,分析了爆轰波碰撞叠加切割柱壳形成破片的过程,找出了柱壳切割效果优良的调整器结构参数取值范围,并开展了最优结构的验证试验。研究结果表明:有效破片生成率随内外层装药厚度比、调整器厚度的增加以及沟槽数量的减小,由一定值逐渐达到100%;当内外层装药厚度比为5、调整器厚度为10 mm或15 mm且开有8或12个沟槽时,有效破片在生成率达到100%的同时兼具较大的平均质量;水井试验回收率为96.3%,获得的有效破片生成率为100%,破片平均长度和宽度分别为39.75 mm和14.2 mm,与仿真结果的误差分别为6.25%和11.25%。该文研究结果可为实现破片战斗部智能可选择化提供借鉴思路。

关键词：爆炸力学爆轰叠加壳体破碎规则破片不均匀加载

基于隐式退化模型的磁共振图像超分辨重建网络

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中国医学物理学杂志 2024年第6期41卷 690-701页

作者：刘环宇郭海鹏刘晓东李晗李君宝哈尔滨工业大学计算学部信息对抗技术研究所黑龙江哈尔滨150080 哈尔滨工业大学电子与信息工程学院自动化测试研究所黑龙江哈尔滨150080

对于使用算法提升磁共振(MR)图像分辨率的研究,现有方法多停留在跨尺寸、同尺寸有监督的超分辨算法研究,提出一种基于隐式退化映射模型的MR图像超分辨重建网络SG-Diffusion,通过掩码自编码器隐式建模MR图像的退化过程,减小实验构建数据... 详细信息

对于使用算法提升磁共振(MR)图像分辨率的研究,现有方法多停留在跨尺寸、同尺寸有监督的超分辨算法研究,提出一种基于隐式退化映射模型的MR图像超分辨重建网络SG-Diffusion,通过掩码自编码器隐式建模MR图像的退化过程,减小实验构建数据集与实际场景下MR图像的域差距,并基于隐式退化模型构建样本对,训练得到基于自引导扩散模型的MR图像重建网络,从而实现无监督同尺寸MR图像的空间分辨率提升。在fastMRI数据集的4倍加速采样脑部MR图像超分辨实验结果显示,本文提出的基于隐式退化模型的MR图像超分辨重建网络能够有效提升退化MR图像的空间分辨率,同时与基于显示退化模型的图像退化重建方法相比,本文提出的SG-Diffusion方法具有更好的重建效果。

关键词：脑部磁共振图像超分辨扩散模型

Multi-resonant broadband Janus-Ring transducer

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Chinese Journal of Acoustics 2020年第3期39卷 387-398页

作者： SUN Shuzhen li junbao Institute of Acoustics Chinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049 Beijing Greatwall Electronic Equipment Co.Ltd B eijing 100082

A Janus-Ring(JR)transducer with two piezoelectric rings placed around a Janus driver is *** rings have radial vibration,whereas the Janus has longitudinal vibration,and a resonance of Helmholtz cavity is observed between *** joining the three resonances,the working frequency bandwidth of the transducer is prominently *** simulation using finite element method,a prototype is finally fabricated and *** show that in the working frequency of 1.8 to 8.0 kHz,the maximum transmitting voltage response(TVR)is 144 dB,and the fluctuations are less than 6 *** with traditional Janus-Helmholtz transducers,the JR transducer has the characteristics of wider bandwidth,greater TVR,and less fluctuations of TVR in working frequency band.

关键词： Ring Helmholtz resonant

Retraced longitudinal stacks low-frequency mosaic cylinder transducer

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Chinese Journal of Acoustics 2022年第2期41卷 143-153页

作者： Lü Kejia li junbao li Yuan Institute of Acoustics Chinese Academy of SciencesBeijing 100190 Beijing Engineering Technology Research Center of Ocean Acoustic Equipment Beijing 100190

A small-size low-frequency horizontal omni-directional cylinder transducer is *** is composed of four cylinder-shaped head mass blocks and four retraced piezoelectric ceramic longitudinal stacks sharing with one back mass *** transducer is analyzed and designed by using finite element method(FEM).A prototype is manufactured and *** results show that the maximum diameter of the transducer is 180 mm,the resonance frequency is 1.5 kHz,the maximum transmitting voltage response level is 131 dB and the maximum source level is above 188 dB,and the directivity of the transducer is horizontal *** transducer has the advantages of low frequency,small size and horizontal omni-directional,and has some good application prospects.

关键词： cylinder directional ceramic

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旅大特稠油储层新型完井液体系的构建与评价

当代化工 2024年第4期53卷 921-924页

作者：徐涛李君宝李进贾立新张帅海洋石油高效开发国家重点实验室北京102209 中海石油(中国)有限公司天津分公司天津300459 中海油能源发展股份有限公司工程技术分公司天津300452

旅大A油田是一个埋藏浅、油质稠、储量大的典型重质特超稠油油藏,热采开发是其有效的开发方式。稠油油藏在储层物性、流体性质及开采工艺方面与常规油藏存在较大差异,现有常规水基完井液体系无法满足需求。针对该油田稠油热采工艺,充分... 详细信息

旅大A油田是一个埋藏浅、油质稠、储量大的典型重质特超稠油油藏,热采开发是其有效的开发方式。稠油油藏在储层物性、流体性质及开采工艺方面与常规油藏存在较大差异,现有常规水基完井液体系无法满足需求。针对该油田稠油热采工艺,充分考虑稠油油藏储层特性、稠油预防乳化增稠和降黏促排的新需求,开展新型完井液体系的构建。通过抑制性、降黏助排性、配伍性及热采高温环境下储层保护效果的评价,建立起适用于稠油的新型有机胺完井液体系。该体系在提升稠油热采井开发储层保护效果的同时,降低完井液综合成本,为渤海油田稠油开发提质增效提供有力保障。

关键词：完井液稠油油藏热采储层保护

Ferroelastic domain identification and toughening mechanism for yttrium tantalate–zirconium oxide

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Journal of Materials Science & Technology 2022年第32期127卷 78-88页

作者： Cheng Luo Cong li Ke Cao junbao li Junhui Luo Qinghua Zhang QianQian Zhou Fan Zhang lin Gu li Yang Yichun Zhou School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China Frontier Research Center of Thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an 710126China School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Engineering BIC-ESATPeking UniversityBeijing 100871China

Yttrium tantalate(YTaO_(4))is the next generation of higher service temperature thermal barrier coatings(TBCs)materials due to its smaller volume effect in phase change,lower thermal conductivity and unique ferroelastic domain ***,the low fracture toughness limits its *** first characterized the diffraction patterns of variants,and two variants(M_(1)and M_(2))observed in transmission electron microscopy(TEM)results were determined from four possible variants by mechanical *** role of Zr^(4+)doping in ferroelastic toughening was explained in *** the increase of Zr^(4+)doping concentration,the monoclinic angle β and the domain rotation angleαdecrease,*** spontaneous strain component and the principal strain in the main space also have a similar decreasing *** decrease of the ferroelastic domain inversion energy barrier is beneficial to the improvement of fracture *** the results of Vickers indentation,we found that Zr^(4+)could be enriched at the domain boundary to inhibit the generation of *** appropriate amount of Zr^(4+)is conducive to the improvement of fracture toughness,and the excessive Zr^(4+)will reduce the fracture toughness due to the generation of by-product t-ZrO_(2).So,the optimal composition is Y_(0.44)Ta_(0.44)Zr_(0.12)O_(2) and the best fracture toughness(2.9–3.8MPa m^(1/2))is equivalent to the commercial *** result will promote the application of a new generation of TBCs.

关键词： Ferroelastic domain Variants Domain switch TBCs Fracture toughness

Research on the relaxor ferroelectric single crystal flexural beam vector hydrophone

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Chinese Journal of Acoustics 2016年第4期35卷 497-507页

作者： YIN Yilong li junbao JIANG Zhipeng Institute of Acoustics Chinese Academy of Sciences

A two-dimensional vector hydrophone was developed utilizing the PMN-PT relaxor ferroelectric single crystal,which is composed of a dual-axis piezoelectric composite flexural beam accelerometer and PZT-5 piezoelectric ceramic *** on the principle of elastic mechanics and underwater particle velocity measurement,the receiving voltage sensitivity of the flexural beam vector hydrophone is *** influence of stress distribution in the flexural beam on the performance of hydrophones is analyzed,and the match between PMNPT single crystal cells and the structure of flexural beam is *** tested results indicate that the PMN-PT hydrophone presents an 11 dB increase in sensitivity and a 3 dB decrease in self-noise than the PZT-5 one.

关键词： PMN PT Research on the relaxor ferroelectric single crystal flexural beam vector hydrophone