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High selectivity reconfigurable filters with controlled channel bandwidth

High selectivity reconfigurable filters with controlled chan...

IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP)

作者： S. F. Peik J. Jiang R. R. Mansour Science and Technology on Underwater Test and Control Laboratory Dalian China

In this paper, we present the design of a novel class of reconfigurable filters allowing a control of bandwidth and maintaining a high Q in all configured states. The concept can be applied to any type of filters including planar, waveguide as well as FBAR filters. The proposed filters have the potential to replace large numbers of fixed filters by a single tunable design. The key idea is to combine high-Q un-tuned resonators with a set of tunable resonators. The selected bands can be controlled by proper placement of fixed transmission zeros generated by the high-Q resonators. The combination allows a highly selective filter response with flat pass-band for all states. Measurements on a planar microstrip filter verify the concept.

关键词： Resonators Tuning Microwave filters Microwave communication Bandwidth Filtering theory

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Numerical analysis on target strength of the air filled cylindrical elastic shell

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Journal of Physics: Conference Series 2018年第3期1087卷

作者： Jihui Wang Guijuan Li Bing Jia Zhenshan Wang Rui Wang Science and Technology on Underwater Test and Control Laboratory Dalian China

Aimed at simulating the air filled finite cylindrical shell target strength, the numerical calculation method of scattering form function and target strength is given in this paper using the theory of Stanton T K. Cylindrical shells of different material properties, thickness, length are calculated, and the results indicate that factor of the material property and dimension is very important. Compared with other kinds of material properties, the gum rubber cylindrical shell has much more greater target strength for low frequency. Factors of radius and thickness have big effect to its fundamental resonance and the choice should be made in accordance with the actual needs. The numerical study provides theoretical basis and design reference for engineering application.

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Achieving high oxidation and hot-cold alternating fatigue resistance die steels via synergistic manipulation of Cr and nanoparticles

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Materials Science and Engineering: A 2025年 942卷

作者： Jing-Ran Sun Bai-Xin Dong Hong-Yu Yang Fang-Chang Xin-Miao Zhong Ai-Min Li Cheng-Gang Wang Zhi-Gang Li Jia Meng Jian Qiao Jie Kang Ming Zhu Shi-Li Shu Feng Qiu Lin Liu State Key Laboratory of Automotive Simulation and Control Jilin University PR China Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and Engineering Jilin University Renmin Street NO. 5988 Changchun Jilin Province 130025 PR China ZhonghangShangda Superalloys Materials Co. Ltd No.16 Wangong Avenue Qinghe County Xingtai City Hebei Province 054800 PR China Technology Research and Development Casting & Forging Research Institute FAW Foundry Co. Ltd Crossing of Hexie Street & Bingwu Road Automotive Industry Development Zone Changchun Jilin Province 130013 PR China Department and Test Center FAW-Volkswagen Automotive Co. Ltd Changchun Jilin Province 130011 PR China School of Mechatronic Engineering and Automation Foshan University No. 33 Guangyun Road Nanhai District Foshan Guangdong Province 528231 PR China Jilin Liyuan Precision manufacturing Co. Ltd. No. 5729 Xi'ning Road Economic Development Zone LiaoYuan Jilin Province 136299 PR China Zhenjiang Xianfeng Automotive Parts Co. Ltd Dantu High tech Industrial Park Zhenjiang Jiangsu Province 212000 PR China School of Mechanical and Aerospace Engineering Jilin University Renmin Street NO. 5988 Changchun 130025 PR China Jilin Jiyan New Materials Technology Co. Ltd No. 21 Ecological East Street Jingyue High tech Zone Changchun 130119 PR China

Hot work die steels are extensively applied in hot forming, where dies are subjected to high temperature and mechanical stresses and are prone to fatigue failure. A novel approach was proposed to synergistically manipulate hot work die steels by increasing Cr content and introducing TiC nanoparticles, showing far superior oxidation resistance and hot-cold alternating fatigue resistance compared to the international high-end DIEVAR die steels. On the one hand, the introduction of ceramic nanoparticles contributed to the enhanced oxidation resistance of the steels by promoting the formation of a thicker and denser Cr 2 O 3 oxide film on the steels surface. On the other hand, the high-temperature microstructure stability and tempering resistance of steels were also improved through microstructure refinement and matrix strengthening. This effectively inhibited the initiation and propagation of hot-cold fatigue cracks, thereby significantly improving the resistance of steels to hot-cold alternating fatigue. This work provides a theoretical basis for understanding the modification of the high-performance hot work die steels.

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The Study of Ocean Ambient Noise Reconstruction in Low and Medium Frequency Bands

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IOP Conference Series: Materials Science and Engineering 2018年第1期428卷

作者： Zhang Liang Wen Fengdan Meng Chunxia Han Jing Science and Technology on Underwater Test and Control Laboratory Dalian 116013 China

Ocean ambient noise is the general background of the sea, the sources of which is highly variable, the generated noise signal is random, it changes with time and space. It is usually considered that ocean ambient noise is a special random process with certain power spectrum, so the broadband stationary random process can be used for fitting the continuous spectral noise. This paper carried out statistical analysis on sample data obtained by continuous observation in one day, and then the statistic characteristics of ambient noise frequency spectrum in low and medium frequency bands can be calculated. Generating filter with specific frequency response based on the probability density function of sound pressure level in each frequency randomly, and ocean ambient noise is reconstructed effectively by Gaussian white noise passing the filter above. The simulation results have important implication for low and medium frequency underwater acoustic signal analysis in lab conditions, and it is helpful to test the performance of platform in the oceanic background.

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Research on the Discharge Properties of the Direct Carbon Fuel Cell with a Molten Metal Anode

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IOP Conference Series: Earth and Environmental Science 2019年第1期223卷

作者： Y B Zhao T L Xiao D Ding Shanghai Institute of Measurement and Testing Technology 1500 Zhangheng Road Shanghai 201203 China Shanghai Key laboratory of Online Test and Control Technology 1500 Zhangheng Road Shanghai 201203 China

In order to research the discharge properties of the direct carbon fuel cell (DCFC) with a molten metal anode, the experimental system with a reactor is designed and constructed. The reaction mechanisms at both anode and cathode are analyzed. The molten Sn and Sb are used as the anodic material for comparison. The cell performance of DCFC is tested before and after discharging in the battery mode and the carbon fuel mode, respectively. In the battery mode, due to the different states of metallic oxides, the current density is not degraded after discharging with the molten Sb anode, but sharply decreases with the molten Sn anode. On the contrary, the cell performance with Sb is much worse than that with Sn after discharging in the carbon fuel mode, which is result from the volatility of Sb together with the reduction of its oxide. The above studies will help to thoroughly understand the underlying mechanism of DCFC with a molten metal anode.

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Modulation feature of underwater target broadband echo spectrum

Modulation feature of underwater target broadband echo spect...

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IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC)

作者： Chen-Yun Fei Li-Sheng Xia-Chun Yan Jia-Bing Li-Gui Juan Science and Technology on Underwater Test and Control Laboratory Dalian China School of Naval Architecture Dalian University of Technology Dalian China

Characteristics of elastic scattering wave depend on target elastic properties, the extraction of elastic wave characteristics is always difficult in underwater target detection by active sonar. Based on the modulation characteristics of broadband echo spectrum produced by target geometry scattering and elastic scattering, the modulation feature of echo spectrum was proposed and studied, expressing how underwater target properties effect on scattering wave spectrum. A sea testing of scaled benchmark and rock broadband acoustic scattering were conducted to verify the theoretical predication, which showed that targets of different properties could be well classified by the modulation feature of echo spectrum.

关键词： Benchmark testing Rocks Azimuth Scattering Frequency modulation Feature extraction

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Target spatial feature abstraction basing on beam forming

Target spatial feature abstraction basing on beam forming

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2016 IEEE/OES China Ocean Acoustics Symposium, COA 2016

作者： Zhang, Zhaohui Hu, Chen Peng, Yuan Zhang, Fengzhen Lin, Mu Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781467399784

underwater target recognition is very difficult because of the complexity of the ocean environment. The existing recognition technologies are mostly based on time domain, frequency domain, and time-frequency domain. Beam forming technology is a method of target recognition that has been researched and has developed rapidly in recent years. This paper applies beam forming and spatial spectrum analysis technology to an underwater echo signal in order to capture target echo and highlight spot and dimension features in the time-space domain. Image processing is used to extract the dimension and experimental data also verifies the feasibility of this method of beam forming. © 2016 IEEE.

关键词： Spectrum analysis

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An Experimental Study on the Behavior Deterioration Trend of Friction Pendulum Bearings with Corrosion Time for Offshore Isolated Bridges

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IOP Conference Series: Earth and Environmental Science 2019年第4期304卷

作者： Guifeng Zhao Yuhong Ma Yanmin Li Liangjian Su Fulin Zhou School of Civil Engineering Guangzhou University Guangzhou 510006 China Guangdong Provincial Key Laboratory of Earthquake Engineering and Applied Technology Key Laboratory of Earthquake Resistance Earthquake Mitigation and Structural Safety Ministry of Education Guangzhou 510405 China. Earthquake Engineering Research & Test Center Key Laboratory of Seismic Control and Structural Safety Guangzhou University Guangzhou 510405 China

At present, the behavior deterioration trend of friction pendulum bearings (FPBs) widely used in offshore bridges under marine environment isn't still clear. In this study, periodic-salt-spray and wetting–drying cycle accelerated corrosion tests were used to simulate the corrosion circumstances of FPBs in the splash and atmospheric zones, respectively. Eight sets of FPBs with a vertical bearing capacity of 35 t were designed as test samples. The environmental factors that affect the bearing behavior deterioration were analyzed; the test accelerated ratios of the factors were discussed; two kinds of test schemes were designed for the FPBs; and the macroscopic appearances of the FPBs at different corrosion times were observed. The trends of the initial static and dynamic friction coefficients with corrosion time were extensively analyzed, and the behavior deterioration trends of the mechanical properties of the FPBs were analyzed. The results show that in both the splash and atmospheric zones, the initial static and dynamic friction coefficients with corrosion time show an increasing periodic curve, but the behavior deterioration trend and period of FPBs in different locations are different. The vertical and horizontal stiffness of FPBs almost did not change with the corrosion time. The trends of equivalent damping ratio with the corrosion time are consistent with the dynamic friction coefficient. Based on the experimental results, the behavior deterioration trends of the initial static and dynamic friction coefficients of FPBs with corrosion time were obtained, which provides a basis for the seismic performance evaluations of offshore isolated bridges in their entire service lifetime.

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Bearing health condition prediction using deep belief network 9

Bearing health condition prediction using deep belief networ...

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9th Annual Conference of the Prognostics and Health Management Society, PHM 2017

作者： Zhao, Guangquan Liu, Xiaoyong Zhang, Bin Zhang, Guohui Niu, Guangxing Hu, Cong Department of Automatic Test and Control Harbin Institute of Technology Harbin Heilongjiang150080 China Department of Electrical Engineering University of South Carolina ColumbiaSC29208 United States Guangxi Key Laboratory of Automatic Detecting Technology and Instruments Guilin University of Electronic Technology Guilin Guangxi541004 China

ISBN: (纸本)9781936263264

Bearings play a critical role in maintaining safety andreliability of rotating machinery. Bearings health conditionprediction aims to prevent unexpected failures and minimizeoverall maintenance costs since it provides decision makinginformation for condition-based maintenance. This paperproposes a Deep Belief Network (DBN)-based data-drivenhealth condition prediction method for bearings. In thisprediction method, a DBN is used as the predictor, whichincludes stacked RBMs and regression output. Our maincontributions include development of a deep leaning-baseddata-driven prognosis solution that does not rely on explicitmodel equations and prognostic expertise, and providingcomprehensive prediction results on five representative runto-failure bearings. The IEEE PHM 2012 challenge datasetis used to demonstrate the effectiveness of the proposedmethod, and the results are compared with two existingmethods. The results show that the proposed method haspromising performance in terms of short-term healthcondition prediction and remaining useful life prediction forbearings. © 2017 Prognostics and Health Management Society. All rights reserved.

关键词： Condition based maintenance

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Lithium-ion battery remaining useful life prediction with long short-term memory recurrent neural network 9

Lithium-ion battery remaining useful life prediction with lo...

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9th Annual Conference of the Prognostics and Health Management Society, PHM 2017

作者： Liu, Yuefeng Zhao, Guangquan Peng, Xiyuan Hu, Cong Department of Automatic Test and Control Harbin Institute of Technology Harbin Heilongjiang150001 China School of Information Engineering Inner Mongolia University of Science and Technology Baotou Inner Mongolia Autonomous region014010 China Guangxi Key Laboratory of Automatic Detecting Technology and Instruments Guilin University of Electronic Technology Guilin Guangxi541004 China

ISBN: (纸本)9781936263264

Lithium-ion batteries play critical roles in many electronicdevices. It is necessary to develop a reliable and accurateremaining useful life (RUL) prediction approach to providetimely maintenance or replacement of battery systems. Anovel RUL prediction approach based on Long Short-termMemory (LSTM) Recurrent Neural Network (RNN) isproposed in this paper. LSTM is able to capture long-termdependencies and model sequential data among the capacitydegradation of lithium-ion batteries. The advantages of ourproposed method include: 1) obtaining high predictionaccuracy without accurate physics-based model or expertiseand 2) decreasing the cumulation errors by multi-step aheadprediction each time, while traditional RUL method predictsone-step ahead once and then uses the current estimatedvalue to predict next one, which causes cumulation errorsincreased. The Center for Advanced Life Cycle Engineering(CALCE) battery datasets are used to demonstrate theeffectiveness of the proposed method. The results show that,compared with echo state networks (ESN), the proposedmethod has higher accuracy, more stable and reliableperformance for lithium-ion batteries RUL prediction. © 2017 Prognostics and Health Management Society. All rights reserved.

关键词： Lithium-ion batteries

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