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学者姓名:黄艳
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Abstract :
GNSS接收机的性能评价是卫星导航领域的重要研究内容.由于GNSS接收机的测试指标繁多,且关联性较弱,无法准确客观的展现一个接收机的性能优劣,本文研究了对导航型接收机性能的综合评价方法,选择测试指标并建立递阶型测试指标体系,之后综合利用层次分析法(Analytic Hierarchy Process,AHP)和模糊综合法(Fuzzy Comprehensive Evaluation,FCE)设计了主观性弱,归一化程度高的综合评价算法.最后利用文中算法对3台不同型号的导航型接收机进行综合性能评价,其结果与专家的主观评价结果一致,证明本算法可以正确的评价接收机的整体性能.
Keyword :
层析分析法 层析分析法 综合评价算法 综合评价算法 GNSS接收机性能评价 GNSS接收机性能评价 模糊综合法 模糊综合法
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GB/T 7714 | 朱江淼 , 董晓飞 , 杨阳 et al. 基于AHP+FCE的GNSS接收机综合性能评价算法研究 [J]. | 宇航计测技术 , 2021 , 41 (3) : 57-63 . |
MLA | 朱江淼 et al. "基于AHP+FCE的GNSS接收机综合性能评价算法研究" . | 宇航计测技术 41 . 3 (2021) : 57-63 . |
APA | 朱江淼 , 董晓飞 , 杨阳 , 高秀娜 , 黄艳 . 基于AHP+FCE的GNSS接收机综合性能评价算法研究 . | 宇航计测技术 , 2021 , 41 (3) , 57-63 . |
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Abstract :
随着北斗三号全球卫星导航系统成功组网,我国的北斗系统迎来了全球服务时代.卫导高精度与5G、人工智能等前沿技术的快速融合发展,为卫星导航的应用与发展提供了有力支撑,也为卫星导航应用领域计量技术的发展提出了更多更高的要求.本文从产业分布、产品发展、规模应用、行业应用、技术发展方面对北斗应用产业的发展现状进行介绍,分析了北斗应用产业对计量、标准、检验检测等质量基础的具体需求,最后梳理和总结了北斗导航应用产业的质量基础工作现状和成果.
Keyword :
应用 应用 卫星导航 卫星导航 质量基础 质量基础 北斗系统 北斗系统
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GB/T 7714 | 黄艳 , 姜燕 , 朱江淼 et al. 北斗系统高精度技术应用质量基础体系的研究与分析 [J]. | 计量与测试技术 , 2021 , 48 (9) : 8-10,14 . |
MLA | 黄艳 et al. "北斗系统高精度技术应用质量基础体系的研究与分析" . | 计量与测试技术 48 . 9 (2021) : 8-10,14 . |
APA | 黄艳 , 姜燕 , 朱江淼 , 刘圆 , 檀恒宇 . 北斗系统高精度技术应用质量基础体系的研究与分析 . | 计量与测试技术 , 2021 , 48 (9) , 8-10,14 . |
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Abstract :
针对拥堵车辆怠速振动造成的城市桥梁疲劳失效风险,利用ABAQUS建立车辆拥堵荷载作用下的车-桥耦合有限元模型,通过动力响应分析和应力循环计数,采用能量法以总应变能密度为损伤参量,计算4种拥堵工况下城市组合梁桥钢箱构造细节的疲劳累积损伤,并通过与规范标准疲劳车畅通运行状态时的损伤对比,综合评估车辆拥堵对城市组合箱梁桥疲劳性能的影响。结果表明:城市组合梁桥在车辆拥堵荷载作用下弹性应变能在总应变能密度值中占主导地位,其疲劳行为是典型的高周疲劳,疲劳损伤主要来自于怠速振动初始的3~5个高应力幅循环;钢箱底板-腹板焊缝构造细节的疲劳累积损伤为母材的2~5倍,焊缝是疲劳性能较薄弱的部位;当典型拥堵车流只包...
Keyword :
车辆拥堵荷载 车辆拥堵荷载 疲劳损伤 疲劳损伤 能量法 能量法 组合梁桥 组合梁桥 车-桥耦合分析 车-桥耦合分析 桥梁工程 桥梁工程
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GB/T 7714 | 陈华婷 , 王伟 , 段守辉 et al. 基于能量法的组合梁桥拥堵车辆怠速振动所致疲劳损伤评估 [J]. | 中国公路学报 , 2021 , 34 (04) : 80-92 . |
MLA | 陈华婷 et al. "基于能量法的组合梁桥拥堵车辆怠速振动所致疲劳损伤评估" . | 中国公路学报 34 . 04 (2021) : 80-92 . |
APA | 陈华婷 , 王伟 , 段守辉 , 黄艳 , 亓路宽 . 基于能量法的组合梁桥拥堵车辆怠速振动所致疲劳损伤评估 . | 中国公路学报 , 2021 , 34 (04) , 80-92 . |
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Abstract :
Urban composite bridges often experience fatigue failure risk induced by congested vehicle idle vibration. To address this problem, ABAQUS was adopted to establish a vehicle-bridge coupled finite element model under congested vehicle loading, along with dynamic response analysis and stress cycle counting. Regarding the total strain energy density as a damage parameter, the cumulative fatigue damage of structural details in the steel box girder of an urban composite bridge under four congestion load cases was calculated relative to the damage caused by a standard fatigue vehicle in an unobstructed state. The influence of vehicle congestion on the fatigue performance of an urban composite box girder bridge was comprehensively evaluated. The results demonstrate that elastic strain energy substantially contributes to the total strain energy density of urban composite girder bridges under vehicle congestion loading; hence, the fatigue behavior is typical high cycle fatigue, whereas fatigue damage is mainly cumulated within 3-5 high stress range cycles at the onset of idle vibration. Accumulated fatigue damage to the structural detail at the bottom flange-to-web weldment is 2-5 times that to the base metal, the fatigue performance of the weldment is therefore more vulnerable. When typical congested traffic flow contains only cars and buses, fatigue damage can be safely evaluated by the idle vibration of a standard fatigue vehicle; however, in some unrestricted road sections, fatigue damage increases significantly due to truck congestion. Since the dynamic effect of engine idle vibration increases the equivalent stress amplitude by 65%, fatigue damage caused by a standard fatigue vehicle under single congestion is 14.7 times that caused by single crossing under unobstructed conditions, thus increasing the risk of fatigue damage of structural details. Cumulative fatigue damage increases with the influence of vehicle congestion, which is affected by congestion load case, traffic volume, and congestion duration. When daily congestion lasts for 4 h, fatigue damage owing to congestion can reach 3.5 times that without congestion. This study can provide a reference for the fatigue assessment of similar bridges and basic theoretical support for the safe operation of existing urban steel bridges. © 2021, Editorial Department of China Journal of Highway and Transport. All right reserved.
Keyword :
Traffic congestion Traffic congestion Vibrations (mechanical) Vibrations (mechanical) ABAQUS ABAQUS Fatigue damage Fatigue damage Vehicles Vehicles Steel bridges Steel bridges Box girder bridges Box girder bridges Strain energy Strain energy Composite bridges Composite bridges Welds Welds Stress analysis Stress analysis
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GB/T 7714 | Chen, Hua-Ting , Wang, Wei , Duan, Shou-Hui et al. Evaluation of Fatigue Damage of Composite Bridges Caused by Congested Vehicle Idle Vibration Based on Energy Approach [J]. | China Journal of Highway and Transport , 2021 , 34 (4) : 80-92 . |
MLA | Chen, Hua-Ting et al. "Evaluation of Fatigue Damage of Composite Bridges Caused by Congested Vehicle Idle Vibration Based on Energy Approach" . | China Journal of Highway and Transport 34 . 4 (2021) : 80-92 . |
APA | Chen, Hua-Ting , Wang, Wei , Duan, Shou-Hui , Huang, Yan , Qi, Lu-Kuan . Evaluation of Fatigue Damage of Composite Bridges Caused by Congested Vehicle Idle Vibration Based on Energy Approach . | China Journal of Highway and Transport , 2021 , 34 (4) , 80-92 . |
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Abstract :
Achieving multi-level properties of chalcogenide phase change materials is highly desirable for high-density data storage, photonic switches and neuromorphic computing etc. In this paper, we report a multi-level implement scheme via a two-step picosecond laser irradiation strategy on the basis of time/space modulations of microstructure and property of Ge2Sb2Te5 (GST) phase change thin films. Unlike the common grey-scale method by multiple laser irradiations at a fixed position, multi-levels of optical properties were obtained by two-step overlapping laser irradiations together with such varied parameters as the overlapping ratio, input energy and two-pulse duration. Variations of the microstructure and optical property were characterized by transmission electron microscope (TEM) and microarea reflectance testing. It showed that the overlapping ratio was an important factor to adjust microstructure patterns and optical properties. With the increase of the overlapping ratio, the optical reflectivity presented a trend of increasing first and then decreasing, mainly because of the effects of the size and distribution of grains from the second laser irradiations. Based on the scheme proposed, a 10-level optical reflectivity could be obtained. The fundamental research performed in this study is of importance to give guideline for high-density storage or big-data processing with phase change materials in the future.
Keyword :
two-step laser irradiation scheme two-step laser irradiation scheme chalcogenide phase change materials chalcogenide phase change materials multi-level optical reflectivity multi-level optical reflectivity microstructure microstructure
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GB/T 7714 | Zhang, Y. Z. , Liu, F. R. , Han, Z. et al. A multi-level optical storage scheme via two-step picosecond laser irradiations: time/space modulations of microstructure and its optical property [J]. | SEMICONDUCTOR SCIENCE AND TECHNOLOGY , 2020 , 35 (3) . |
MLA | Zhang, Y. Z. et al. "A multi-level optical storage scheme via two-step picosecond laser irradiations: time/space modulations of microstructure and its optical property" . | SEMICONDUCTOR SCIENCE AND TECHNOLOGY 35 . 3 (2020) . |
APA | Zhang, Y. Z. , Liu, F. R. , Han, Z. , Li, W. Q. , Huang, Y. , Sun, N. X. . A multi-level optical storage scheme via two-step picosecond laser irradiations: time/space modulations of microstructure and its optical property . | SEMICONDUCTOR SCIENCE AND TECHNOLOGY , 2020 , 35 (3) . |
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Abstract :
抗干扰性能测试是评价导航接收机性能的重要内容,对其中两个关键指标—干扰抑制度和干扰恢复时间进行了研究.首先构建了基于导航信号模拟器的接收机抗干扰测试系统,合理地确定接收机的约束条件,通过调节干扰信号观察接收机定位性能到达约束条件,测试接收机的干扰抑制度;通过控制干扰信号输出时间,测试接收机在干扰信号过后能够恢复正常定位的延时,从而测出接收机的干扰恢复时间;最后分别对两个不同型号的接收机进行真实测试,两台接收机的性能都因干扰信号威胁而降低,干扰抑制度和干扰恢复时间的测试结果与各自整体性能水平匹配,说明该测试方法能正确评估接收机抗干扰性能.
Keyword :
抗干扰性能 抗干扰性能 导航信号模拟器 导航信号模拟器 干扰抑制度 干扰抑制度 GNSS接收机 GNSS接收机 干扰恢复时间 干扰恢复时间
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GB/T 7714 | 朱江淼 , 高秀娜 , 黄艳 et al. GNSS接收机抗干扰性能关键指标测试方法的研究与实现 [J]. | 电子测量与仪器学报 , 2020 , 34 (3) : 135-141 . |
MLA | 朱江淼 et al. "GNSS接收机抗干扰性能关键指标测试方法的研究与实现" . | 电子测量与仪器学报 34 . 3 (2020) : 135-141 . |
APA | 朱江淼 , 高秀娜 , 黄艳 , 马培香 , 乔孟元 . GNSS接收机抗干扰性能关键指标测试方法的研究与实现 . | 电子测量与仪器学报 , 2020 , 34 (3) , 135-141 . |
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Abstract :
Thermally induced residual stresses across the TSV-Cu/TiW/SiO2/Si interface in through-silicon vias (TSVs) have raised serious concerns about mechanical and electrical reliability in 3D ICs. The lack of a nanometer-precision measurement technique for the TSV interfacial stress gradient makes the interface failure mechanism unclear. In this work, we propose an ion beam layer removal (ILR) method for determining the residual stress in the as-fabricated TSV-Cu/TiW/SiO2/Si interface on a nanoscale to facilitate identification of the failure mechanism of the TSV-Cu/TiW/SiO2/Si interface in as-fabricated TSVs. The measurement results showed that the residual stress fluctuates across the TSV-Cu/TiW/SiO2/Si interface and that both compressive stress and tensile stress existed within the interface system. Compressive stress occurred at all three interfaces, the TSV-Cu/TiW, TiW/SiO2, and SiO2/Si interfaces, but transitioned to tensile stress at a distance of 25-45 nm from these interfaces. The highest level of shear stress concentration appeared inside the TSV-Cu at a distance of approximately 45 nm from the TSV-Cu/TiW interface. This shear stress concentration explains the experimentally observed TSV interfacial cracking phenomenon.
Keyword :
Failure mechanism Failure mechanism TSV-Cu/TiW/SiO2/Si interface TSV-Cu/TiW/SiO2/Si interface Nanoscale Nanoscale ILR method ILR method Residual stress Residual stress
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GB/T 7714 | Chen, S. , En, Y. F. , Li, G. Y. et al. An ion beam layer removal method of determining the residual stress in the as-fabricated TSV-Cu/TiW/SiO2/Si interface on a nanoscale [J]. | MICROELECTRONICS RELIABILITY , 2020 , 112 . |
MLA | Chen, S. et al. "An ion beam layer removal method of determining the residual stress in the as-fabricated TSV-Cu/TiW/SiO2/Si interface on a nanoscale" . | MICROELECTRONICS RELIABILITY 112 (2020) . |
APA | Chen, S. , En, Y. F. , Li, G. Y. , Wang, Z. Z. , Gao, R. , Ma, Rui et al. An ion beam layer removal method of determining the residual stress in the as-fabricated TSV-Cu/TiW/SiO2/Si interface on a nanoscale . | MICROELECTRONICS RELIABILITY , 2020 , 112 . |
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Abstract :
On-chip photonics devices relying on the weak, volatile thermo-optic or electro-optic effects of silicon usually suffer from high insertion loss (IL) and a low refractive index coefficient. In this paper, we designed two novel 1 x 1 and 1 x 2 phase-change optical switches based on a signal-mode Si waveguide integrated with a Ge2Sb2Te5(GST) top clad layer, respectively. The three-state switch including amorphous GST (a-GST), face centered cubic crystalline phase (FCC-GST) and hexagonal crystalline phase (HCP-GST) operated by utilizing the dramatic difference in the optical constants between the amorphous and two crystalline phases of GST. In the case of the 1 x 1 optical switch, an extinction ratio (ER) of 8.9 dB and an extremely low IL of 0.8 dB were achieved using an optimum GST length of only 2 mu m. While for the 1 x 2 optical switch, low ILs in the range of 0.15 similar to 0.35 dB for both 'cross' (a-GST) and 'bar' (FCC-GST and HCP-GST) states were also obtained. Additionally, we found that both ILs and mode losses of the switch with HCP-GST were about half lower than those with FCC-GST, which means FCC-GST could be instituted by HCP-GST in the traditional ovonic switch with the consideration of low loss. This research provides the fundamental understanding for the realization of low loss and non-volatile Si-GST hybrid optical switches, with potential for future communication networks.
Keyword :
low loss low loss Si waveguide Si waveguide optical switch optical switch non-volatile non-volatile phase-change materials phase-change materials
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GB/T 7714 | Li, Y. , Liu, F. R. , Han, G. et al. Design of low loss 1 x 1 and 1 x 2 phase-change optical switches with different crystalline phases of Ge(2)Sb(2)Te(5)films [J]. | NANOTECHNOLOGY , 2020 , 31 (45) . |
MLA | Li, Y. et al. "Design of low loss 1 x 1 and 1 x 2 phase-change optical switches with different crystalline phases of Ge(2)Sb(2)Te(5)films" . | NANOTECHNOLOGY 31 . 45 (2020) . |
APA | Li, Y. , Liu, F. R. , Han, G. , Chen, Q. Y. , Zhao, Z. P. , Xie, X. X. et al. Design of low loss 1 x 1 and 1 x 2 phase-change optical switches with different crystalline phases of Ge(2)Sb(2)Te(5)films . | NANOTECHNOLOGY , 2020 , 31 (45) . |
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Abstract :
Phase-change materials were highly promising for next-generation nonvolatile data storage technology and their properties were usually improved by doping. In this paper, the pronounced effects of Sn doping (0%, 10%, 30%) on crystallization behaviors of Ge2Sb2Te5 (GST) film induced by a picosecond pulsed laser were investigated in detail. The TEM observations presented the crystallization threshold, melting threshold and ablation threshold all decreased with the increasing of Sn doping while the crystal structure and crystallization behavior has not been changed. After single pulse Gaussian laser irradiation, the morphology of crystallized films for GST and Sn-doped GST all presented an ingot-like microstructure at higher laser fluence and equiaxed crystal microstructure at lower laser fluence, which was mainly caused by the temperature gradient. The local grain refinement was found in GSTSn30% films because weaker Sn-Te bond (359.8 kJ/mol) replaced the stronger Ge-Te bond (456 kJ/mol), which was also proved by X-ray photoelectron spectroscopy (XPS). This eventually led to a decline in nucleation energy barrier and increased nucleation rate.
Keyword :
Sn doping Sn doping Ge2Sb2Te5 Ge2Sb2Te5 crystallization behavior crystallization behavior picosecond pulsed laser picosecond pulsed laser
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GB/T 7714 | Li, W. Q. , Liu, F. R. , Zhang, Y. Z. et al. Influence of Sn dopant on the crystallization of amorphous Ge2Sb2Te5 by a picosecond pulsed laser irradiation [C] . 2019 . |
MLA | Li, W. Q. et al. "Influence of Sn dopant on the crystallization of amorphous Ge2Sb2Te5 by a picosecond pulsed laser irradiation" . (2019) . |
APA | Li, W. Q. , Liu, F. R. , Zhang, Y. Z. , Huang, Y. , Li, S. . Influence of Sn dopant on the crystallization of amorphous Ge2Sb2Te5 by a picosecond pulsed laser irradiation . (2019) . |
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Abstract :
Whether the equipment terminal with satellite positioning is in the detection method within the set range deserves attention, which determines the success or failure of electronic fence design. The idea of classification is now intended to be used in such detection, this paper proposes an entry fence detection algorithm based on support vector machine (SVM). The algorithm selects the appropriate kernel function according to the positioning data characteristics of the satellite positioning terminal. The kernel function and error penalty parameters are obtained by grid search method. The detection accuracy is adjusted to determine the optimal threshold. The algorithm verification with the measured data shows that the accuracy of entry fence detection can reach 80-96%, which is much higher than the accuracy of 43-67% directly obtained, indicating that the algorithm is reliable and effective and has high practical value. © 2019 IEEE.
Keyword :
Signal detection Signal detection Support vector machines Support vector machines Satellites Satellites Tracking (position) Tracking (position) Fences Fences
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GB/T 7714 | Jiangmiao, Zhu , Xiuna, Gao , Yan, Huang et al. Research and implementation on entry fence detection algorithm of satellite positioning terminal [C] . 2019 : 1468-1475 . |
MLA | Jiangmiao, Zhu et al. "Research and implementation on entry fence detection algorithm of satellite positioning terminal" . (2019) : 1468-1475 . |
APA | Jiangmiao, Zhu , Xiuna, Gao , Yan, Huang , Jing, Zhang , Chunliu, Gao . Research and implementation on entry fence detection algorithm of satellite positioning terminal . (2019) : 1468-1475 . |
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