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Modeling and Analysis of Vibration Characteristics of Rectangular Plate with Circular Through Hole Under Complex Boundary Conditions
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作者 TANG Tianyi HE Yijie +3 位作者 WU Jiajun DONG Menglong WANG Gang NI Junfang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第4期515-525,共11页
This paper presents a method to study the free vibration of a plate with circular holes.The circular hole is regarded as a virtual small plate in which the mass density and Young's modulus are zero.Therefore,the f... This paper presents a method to study the free vibration of a plate with circular holes.The circular hole is regarded as a virtual small plate in which the mass density and Young's modulus are zero.Therefore,the free vibration problem of the circular hole plate can be transformed into the free vibration problem of the equivalent rectangular plate with non-uniform thickness.The model is derived from the spectral geometry method(SGM),and the displacement of the plate with circular holes is expanded by the modified Fourier series.Virtual springs are added to the boundary of the plate to simulate the boundary conditions of simply supported and fixed supports.The accuracy of this method is verified by comparison with the finite element calculation results.The relationship between modal numerical solutions of plates with circular holes and boundary conditions and geometry of the plate is studied. 展开更多
关键词 round hole plate spectral geometry method(SGM) energy method virtual spring
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轴承故障交叉项时频诊断方法的研究 被引量:2
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作者 杨龙兴 贾民平 王强锋 《振动工程学报》 EI CSCD 北大核心 2008年第1期66-70,共5页
在分析调幅信号Wigner-Ville交叉项分布特征的基础上,提出了使用交叉项"虚互谱能量"诊断调幅型机械故障的新方法,并利用设计的带通核函数,提取交叉项"虚互谱能量",最后使用具有调幅故障的轴承冲击共振滤波数据,验... 在分析调幅信号Wigner-Ville交叉项分布特征的基础上,提出了使用交叉项"虚互谱能量"诊断调幅型机械故障的新方法,并利用设计的带通核函数,提取交叉项"虚互谱能量",最后使用具有调幅故障的轴承冲击共振滤波数据,验证了方法在实际应用中的有效性。 展开更多
关键词 轴承 故障诊断 带通核函数 交叉项“互谱能量
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旋转机械故障交叉项时频诊断方法 被引量:1
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作者 杨龙兴 王强锋 贾民平 《农业机械学报》 EI CAS CSCD 北大核心 2008年第8期153-156,共4页
首先分析了调幅信号Wigner-Ville分布的交叉项分布特征,提出了使用交叉项"虚互谱能量"诊断调幅型机械故障的新方法,并利用设计的带通核函数,提取了理论调幅信号的交叉项"虚互谱能量",最后使用具有调幅故障的实际齿... 首先分析了调幅信号Wigner-Ville分布的交叉项分布特征,提出了使用交叉项"虚互谱能量"诊断调幅型机械故障的新方法,并利用设计的带通核函数,提取了理论调幅信号的交叉项"虚互谱能量",最后使用具有调幅故障的实际齿轮数据,验证了方法在实际应用中的有效性。 展开更多
关键词 调幅型机械 带通核函数 交叉项“互谱能量 故障诊断
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OFDM信号的新型自动识别与解调技术研究 被引量:1
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作者 陈菊 《通信技术》 2018年第12期2805-2811,共7页
近年来,通信领域越来越多地使用OFDM信号,有关OFDM的识别和解调也成为业界的热点问题之一。在对OFDM信号特性进行分析的基础上,设计了用于OFDM信号识别的新型四阶累量特征提取方法;研究和讨论了OFDM子载波间隔、频率及数目自动测量等调... 近年来,通信领域越来越多地使用OFDM信号,有关OFDM的识别和解调也成为业界的热点问题之一。在对OFDM信号特性进行分析的基础上,设计了用于OFDM信号识别的新型四阶累量特征提取方法;研究和讨论了OFDM子载波间隔、频率及数目自动测量等调制规格分析技术;定义了频带边界虚音的概念,提出了新颖的基于频带边界虚音能量检测的符号速率估计算法;讨论分析了频偏与载波间干扰的关系,提出了基于迭代运算的载波频率精确估计算法。实际应用结果表明了此种OFDM信号自动识别与解调技术的有效性。 展开更多
关键词 信号自动识别 信号解调 OFDM 边界能量
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A Worsted Yarn Virtual Production System Based on BP Neural Network 被引量:2
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作者 董奎勇 于伟东 《Journal of Donghua University(English Edition)》 EI CAS 2004年第4期34-37,共4页
Back-Propagation (BP) neural network and its modified algorithm are introduced. Two series of BP neural network models have been established to predict yarn properties and to deduce wool fiber qualities. The results f... Back-Propagation (BP) neural network and its modified algorithm are introduced. Two series of BP neural network models have been established to predict yarn properties and to deduce wool fiber qualities. The results from these two series of models have been compared with the measured values respectively, proving that the accuracy in both the prediction model and the deduction model is high. The experimental results and the corresponding analysis show that the BP neural network is an efficient technique for the quality prediction and has wide prospect in the application of worsted yarn production system. 展开更多
关键词 BP neural network yarn properties top qualities virtual production PREDICTION deduction.
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Energy management and coordination control of microgrid in elevated station of urban rail transit 被引量:2
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作者 LU Tao-tao TIAN Ming-xing +1 位作者 ZHANG Ning GAO Feng-yang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第4期398-404,共7页
The rapid development of urban rail transit brings convenience to the public,but its huge energy consumption problem cannot be ignored.A microgrid composed of photovoltaic power generation unit,regenerative braking en... The rapid development of urban rail transit brings convenience to the public,but its huge energy consumption problem cannot be ignored.A microgrid composed of photovoltaic power generation unit,regenerative braking energy feedback unit and battery energy storage unit is proposed,which provides green power for the station.In order to suppress the fluctuation of photovoltaic power generation and the intermittence of regenerative braking feedback energy,the energy management mode of microgrid is designed according to the illumination situation,braking energy feedback situation,battery state of charge and so on.In addition,a coordination control method based on virtual synchronous generator(VSG)is proposed to realize smooth switching among modes.Finally,the proposed energy management and coordination control method for elevated station microgrid is verified by Matlab/Simulink.The results show that the elevated station microgrid can operate safely and reliably under various energy management modes and realize smooth switching among modes. 展开更多
关键词 urban rail transit elevated station saving energy and reducing consumption MICROGRID virtual synchronous generator(VSG) regenerative braking energy feedback
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Holistic Discourse in the Network Cognitive Modeling
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作者 A. N. Raikov 《Journal of Mathematics and System Science》 2013年第10期519-530,共12页
The purpose of this paper is to pose a new question to speed-up mutual understanding among team members or/and group of experts when communicating over the Internet in forms of virtual collaboration, electronic brains... The purpose of this paper is to pose a new question to speed-up mutual understanding among team members or/and group of experts when communicating over the Internet in forms of virtual collaboration, electronic brainstorming, network strategic conversation, etc. We have previously proposed an approach that the convergent control mechanism based on the fundamental principles of thermodynamic and inverse problem solution method, as well as various artificial intelligence techniques, be incorporated into the communicative process. This paper shows a further development of the approach in terms of applying The Fuzzy Tychonoff Theorem along with quantum techniques provide to reach a high level of holistic discourse which is achieved not only through the application of fundamental principles of compactness of the topological space, but also utilizing quantum entanglement and complementarity principles for discourse structuring in a special way. The approach is implemented as the Responsibility Thinking System (RTS) tested in the course of finding the decisions of the real life issues. 展开更多
关键词 Cognitive modeling convergence DECISION-MAKING DISCOURSE NETWORK inverse task solution quantum principals topological space.
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“万有斥力”和正反物质世界的对称性 被引量:2
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作者 吴永汉 张中明 翟应田 《云南大学学报(自然科学版)》 CAS CSCD 2001年第1期27-31,共5页
首先提出正物质质量与反物质质量之间的相互作用力可能是“万有斥力”和正反物质世界对称性的假设 .提供了一个检验是否存在“万有斥力”的实验方案和正反物质在宇宙中的可能分布状况 .引入了虚质量、虚能量和虚动量概念 ,指出时间的流... 首先提出正物质质量与反物质质量之间的相互作用力可能是“万有斥力”和正反物质世界对称性的假设 .提供了一个检验是否存在“万有斥力”的实验方案和正反物质在宇宙中的可能分布状况 .引入了虚质量、虚能量和虚动量概念 ,指出时间的流逝也是一种运动形式 . 展开更多
关键词 万有引力 万有斥力 对称性 质量 虚能量 动量 正反物质世界 正物质质量 反物质质量 时间
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Variations of energy metabolism and adenosine Triphosphatase activity in gastric mucosa in chronic atrophic gastritis rats with Qi deficiency and blood stasis syndrome and effect of Zhiweifangbian capsule 被引量:7
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作者 Yongqiang Duan Weidong Cheng +4 位作者 Yingxia Cheng Hongyan Li Xueyan Li Liming Zhu Xiaoyi Yang 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2013年第4期500-504,共5页
OBJECTIVE: To study the effects of Zhiweifangbian (ZWFB) capsule on lactic dehydrogenase (LDH), succinic dehydrogenase (SDH) and ATPase activities in gastric mucosa of chronic atrophic gastritis (CAG) rats with Qi def... OBJECTIVE: To study the effects of Zhiweifangbian (ZWFB) capsule on lactic dehydrogenase (LDH), succinic dehydrogenase (SDH) and ATPase activities in gastric mucosa of chronic atrophic gastritis (CAG) rats with Qi deficiency and blood stasis syndrome. METHODS: Totally 90 rats were randomly divided into 2 groups: normal group (n=10) and modelgroup (n=80). The CAG rat model of Qi deficiency and blood stasis type was induced by synthetic methods. After modeling for 12 weeks and the successful CAG model was determined, the CAG model rats were divided by random number table into model group (MG), ZWFB high-dose group (ZWFBH), ZWFB middle-dose group (ZWFBM), ZWFB low-dose group (ZWFBL) and Weimeisu group (WM), 9 rats in each group. The rats in the normal and model groups were intragastrically administrated with distilled water, 10 mL/kg every day; the ZWFB high-dose group with ZWFB, 0.6 g/ kg -1 · d -1 ; the ZWFB middle-dose group with ZWFB, 0.3 g/kg -1 · d -1 ; the ZWFB low-dose group with ZWFB, 0.15 g/kg -1 · d -1 , and the WM group with suspension of WM , 0.25 g/kg -1 · d -1 . The treatment was given for 90 consecutive days. Then general survival states were observed and the activities of LDH, SDH, Na + -K + -ATPase and Ca 2+ -Mg 2+ -ATPase in gastric mucosa tissue were detected. RESULTS: Compared with the normal group, activity of LDH in the gastric mucosa (P<0.05) and activities of SDH, Na + -K + -ATPase and Ca 2+ -Mg 2+ -ATPase significantly decreased in the normal group (P<0.05). Compared with the model group the activity of LDH decreased and activities of SDH, Na + -K + -ATPase and Ca 2+ -Mg 2+ -ATPase significantly increased in the high dose ZWFB group (P<0.05). CONCLUSION: ZWFB capsule can promote energy metabolism and ATPase activity in the gastric mucosa cell, so as to protect the function of the gastric mucosa cell. 展开更多
关键词 Qi deficiency blood stasis Gastritis atrophic Lactic dehydrogenase Succinate dehydrogenase Zhiweifangbian capsule
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