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Study on theoretical model for electrical explosion resistivity of Al/Ni reactive multilayer foil

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Defence Technology（防务技术） 2024年第2期32卷 348-356页

作者： Zehao Wang Tao Wang Pengfei Xue Mingyu Li qingxuan Zeng State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China China Ship Development and Design Center Wuhan 430064China

Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization of EFIs.Al/Ni RMF with different bilayer thicknesses and bridge dimensions were prepared by MEMS technology and electrical explosion tests were carried out.According to physical and chemical reactions in bridge,the electrical explosion process was divided into 5 stages:heating of condensed bridge,vaporization and diffusion of Al layers,intermetallic combination reaction,intrinsic explosion,ionization of metal gases,which are obviously shown in measured voltage curve.Effects of interface and grain boundary scattering on the resistivity of film metal were considered.Focusing on variations of substance and state,the resistivity was developed as a function of temperature at each stage.Electrical explosion curves were calculated by this model at different bilayer thicknesses,bridge dimensions and capacitor voltages,which showed an excellent agreement with experimental ones.

关键词： Al/Ni reactive multilayer foil Electrical explosion Resistivity model Phase transition Calculation

Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips

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Defence Technology（防务技术） 2024年第2期32卷 309-316页

作者： Jie Ren Yunfeng Li Mingyu Li Xingyu Wu Jiabao Wang qingxuan Zeng State Key Laboratory of Explosion and Technology Beijing Institute of TechnologyBeijing 100081China

Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.

关键词： Copper-based azide chips Spectrophotometry Separation method Quantitative analysis Ignition ability

Spatial-temporal variability of submesoscale currents in the South China Sea

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Journal of Oceanology and Limnology 2019年第2期37卷 474-485页

作者： LI Jianing DONG Jihai yang qingxuan ZHANG Xu Physical Oceanography Laboratory/CIMST Ocean University of China and Qingdao National Laboratory for Marine Science and Technology Qingdao 266000 China Marine Science College Nanjing University of Information Science & Technology Nanjing 210044 China College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao 266000 China

Spatial and seasonal variabilities of submesoscale currents in the northeastern South China Sea are investigated by employing a numerical simulation with a horizontal resolution of 1km. The results suggest that submesoscale currents are widespread in the surface mixed layer mainly due to the mixed layer instabilities and frontogenesis. In horizontal, submesoscale currents are generally more active in the north than those in the south, since that active eddies, especially cyclonic eddies, mainly occur in the northern area. Specifically, submesoscale currents are highly intensified in the east of Dongsha Island and south of Taiwan Island. In temporal sense, submesoscale currents are more active in winter than those in summer, since the mixed layer is thicker and more unstable in the winter. The parameterization developed by Fox-Kemper et al. is examined in terms of vertical velocity, and the results suggest that it could reproduce the vertical velocity if mixed layer instability dominates there. This study improves our understanding of the submesoscale dynamics in the South China Sea.

关键词： submesoscale currents spatial-seasonal variability South China Sea (SCS)

Impact of eddies on ocean diapycnal mixing in Gulf Stream region

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Science China Earth Sciences 2014年第6期57卷 1407-1414页

作者： LI Min XIE LingLing yang qingxuan TIAN JiWei Physical Oceanography Laboratory Ocean University of China Key Laboratory of Climate Resources and Environment in Continental Shelf Sea and Deep SeaCollege of Ocean and Meteorology Guangdong Ocean University

Based on high-resolution,Array for Real-time Geostrophic Oceanography(Argo)profiles and Sea Level Anomaly(SLA)data,this study statistically analyzes and compares turbulent diapycnal mixing profiles inside and outside mesoscale eddies in the Gulf Stream region.The result indicates that average diapycnal diffusivity at 300–540 m depths in anticyclonic eddies reaches4.0×10-5 m2 s-1.This is significantly higher than the 1.6×10-5 m2 s-1 outside eddies and 0.8×10-5 m2 s-1 in cyclonic eddies.Probabilities of diapycnal diffusivity greater than 10-4 m2 s-1 within anticyclonic and cyclonic eddies and outside eddies are29%,5%and 12%,respectively.However,magnitudes of average diapycnal diffusivity at 540–900 m depths in these three cases are of the same order,10-5 m2 s-1.Twenty-four of a total 38 anticyclonic eddies had enhanced mixing in the ocean interior,and 22 were observed during or shortly after strong winds.The coincidence between enhanced mixing and strong wind stress indicates that more wind-induced,near-inertial wave energy propagates downward in anticyclonic eddies.The deeper part of 12 profiles(below 540 m)in anticyclonic eddies had vertical overturns with Thorpe scale exceeding 5 m,among which three profiles had overturns reaching 20 m.Enhanced mixing may have occurred in deep layers of some profiles,although it was not evident in average conditions.

关键词：海洋学涡旋混合流区配置文件扩散系数反气旋统计学分析

中高温及低温作用后超高韧性水泥基复合材料的力学性能

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复合材料学报 2024年第4期41卷 2014-2030页

作者：钱维民苏骏史庆轩李扬嵇威西安建筑科技大学土木工程学院西安710055 湖北工业大学土木建筑与环境学院武汉430068

为研究超高韧性水泥基复合材料(UHTCC)在200~−100℃温度作用后的力学性能,设计了不同纤维体积掺量的UHTCC,经中高温和低温作用后进行基本力学性能试验,通过UHTCC强度和变形等参数评价了中高温和低温作用后UHTCC的力学性能。结果表明:纤... 详细信息

为研究超高韧性水泥基复合材料(UHTCC)在200~−100℃温度作用后的力学性能,设计了不同纤维体积掺量的UHTCC,经中高温和低温作用后进行基本力学性能试验,通过UHTCC强度和变形等参数评价了中高温和低温作用后UHTCC的力学性能。结果表明:纤维的掺入能有效改善基体的脆性,提升材料的韧性;同时温度作用导致材料内部出现初始缺陷,对UHTCC的力学性能有明显的影响,且低温作用的影响要明显高于高温作用,当温度降低至−100℃时,UHTCC强度最大降低约75%,变形最大降低约92%,但温度作用未对UHTCC的泊松比产生明显影响。在此基础上提出了中高温及低温作用后UHTCC轴压和轴拉应力-应变关系回归模型,为UHTCC材料在极端温度环境下的性能设计和工程应用提供参考。

关键词：超高韧性水泥基复合材料中高温低温力学性能本构模型

Mooring observations of internal solitary waves in the deep basin west of Luzon Strait

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Acta Oceanologica Sinica 2014年第3期33卷 82-89页

作者： HUANG Xiaodong ZHAO Wei TIAN Jiwei yang qingxuan Physical Oceanography Laboratory Ocean University of China

A total of 137 internal solitary waves （ISWs） are captured during a field experiment conducted in the deep basin west of the Luzon Strait （LS） from March to August, 2010. Mooring observations reveal that a fully developed ISW owns a maximum westward velocity of more than 1.8 m/s and an amplitude of about 200 m. The ISWs in the South China Sea （SCS） are most active in July, which may be due to the strong stratification in summer. Most of the ISW episodes are detected around and after the 1st or 15th lunar day, indicating that the ISW in the SCS is triggered by astronomic tides. Half part of the observed ISWs were detected around 19：00 local time, which can be explained by the fact that type-a ISWs emerged in the evening at roughly the same time each day. The propagation direction of the ISWs and the astronomic tides in the LS show that the area south of the Batan Island is probably the main source region of the type-a ISWs, while the area south of Itbayat Island and south of the Batan Island is likely the main source region of the type-b ISWs observed at the mooring. Moreover, for the resonance of semidiurnal internal tides emitting from the double ridges in the LS, the underwater ridge south of the Itbayat Island and south of the Batan Island is believed to favor the generation of the energetic ISWs.

关键词： internal solitary wave South China Sea observation nonlinear internal wave

Estimation of eddy heat transport in the global ocean from Argo data

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Acta Oceanologica Sinica 2014年第1期33卷 42-47页

作者： ZHANG Zhiwei ZHONG Yisen TIAN Jiwei yang qingxuan ZHAO Wei Key Laboratory of Physical Oceanography Ocean University of China School of Earth and Atmospheric Sciences Georgia Institute of Technology

The Argo data are used to calculate eddy（turbulence） heat transport（EHT） in the global ocean and analyze its horizontal distribution and vertical structure.We calculate the EHT by averaging all the v ′,T ′ profiles within each 2 ×2 bin.The velocity and temperature anomalies are obtained by removing their climatological values from the Argo ＂instantaneous＂ values respectively.Through the Student＇s t-test and an error evaluation,we obtained a total of 87% Argo bins with significant depth-integrated EHTs（D-EHTs）.The results reveal a positive-and-negative alternating D-EHT pattern along the western boundary currents（WBC） and Antarctic Circumpolar Current（ACC）.The zonally-integrated D-EHT（ZI-EHT） of the global ocean reaches 0.12 PW in the northern WBC band and –0.38 PW in the ACC band respectively.The strong ZI-EHT across the ACC in the global ocean is mainly caused by the southern Indian Ocean.The ZI-EHT in the above two bands accounts for a large portion of the total oceanic heat transport,which may play an important role in regulating the climate.The analysis of vertical structures of the EHT along the 35 N and 45 S section reveals that the oscillating EHT pattern can reach deep in the northern WBC regions and the Agulhas Return Current（ARC） region.It also shows that the strong EHT could reach 600 m in the WBC regions and 1 000 m in the ARC region,with the maximum mainly located between 100 and 400 m depth.The results would provide useful information for improving the parameterization scheme in models.

关键词： eddy heat transport Argo mesoscale eddy global ocean

多层级异质异构吸波超材料功能化设计及熔融沉积3D打印

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机械工程学报 2024年第3期60卷 319-327页

作者：杨贞梁庆宣段玉冰刘攀王昕李涤尘西安交通大学机械工程学院西安710049

针对吸波材料向工程应用方向发展需具备轻质和宽带吸波的关键需求,提出了一种有损谐振结构和功能化介质层调控的多层级复合异质异构吸波超材料,通过对介质层进行仿生结构化设计实现吸波超材料轻量化和宽带吸波性能。将热塑性聚合物材料... 详细信息

针对吸波材料向工程应用方向发展需具备轻质和宽带吸波的关键需求,提出了一种有损谐振结构和功能化介质层调控的多层级复合异质异构吸波超材料,通过对介质层进行仿生结构化设计实现吸波超材料轻量化和宽带吸波性能。将热塑性聚合物材料和银铜合金复合制备了特定电导率的复合材料,通过优化银铜合金重量比和复合材料的打印工艺实现了谐振结构电导率的精确控制。基于此,设计了两层有损谐振结构层来调控宽带阻抗匹配和欧姆损耗,利用双材料熔融沉积3D打印工艺实现了多层级异质异构吸波超材料的可控制备。所制备的吸波超材料等效密度为0.3 g/cm3,电磁性能测试结果表明在垂直入射条件下,吸波超材料在3.8~19.24GHz频段实现了高效吸波性能。同时,电磁波在横电波(Transverse electric,TE)和横磁波(Transverse magnetic,TM)模式下、入射角在50°范围内时,吸波超材料都具有良好的宽带吸波性能。这种多层级异质异构吸波超材料的设计和制造方法为推动吸波材料向工程应用化方向发展提供了技术支撑。

关键词：多层级异质异构吸波超材料 3D打印

混杂钢纤维超高性能混凝土轴拉力学性能及本构模型

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复合材料学报 2024年第1期41卷 383-394页

作者：王秋维梁林史庆轩西安建筑科技大学土木工程学院西安710055

通过单轴受拉试验,研究了平直型(短直、长直)和端钩钢纤维混掺的超高性能混凝土(Ultra-high performance concrete,UHPC)轴心受拉力学性能,基于试验结果分析了钢纤维掺量和混杂配比对UHPC抗拉强度、应变能力、韧性等的影响。结果表明:U... 详细信息

通过单轴受拉试验,研究了平直型(短直、长直)和端钩钢纤维混掺的超高性能混凝土(Ultra-high performance concrete,UHPC)轴心受拉力学性能,基于试验结果分析了钢纤维掺量和混杂配比对UHPC抗拉强度、应变能力、韧性等的影响。结果表明:UHPC轴拉试件发生多缝延性破坏,且宏观主裂缝的倾斜、弯曲程度随端钩纤维的混掺越发明显;混杂短直和端勾钢纤维UHPC的轴拉性能随着端勾纤维掺量的增大而显著提升,而混掺长直和端勾钢纤维UHPC的轴拉性能呈相反变化趋势;混杂钢纤维在UHPC受拉过程中呈现出逐级、分层次、相互作用的阻裂增韧特点,短直和端钩钢纤维掺量均为1.0vol%的UHPC轴拉力学性能最佳,其抗拉强度、应变能力和韧性同比单掺短直纤维试件分别提高28.2%、147%和31.1%。基于实测轴拉应力-应变曲线分析,提出了考虑纤维相互作用和纤维增强因子的混杂钢纤维UHPC轴拉本构模型,与相关试验曲线吻合良好,可用于预测UHPC受拉应力-应变关系。

关键词： UHPC 混杂钢纤维应力-应变曲线轴拉力学性能本构模型