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学者姓名:李建平
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摘要 :
股票价格指数度量并反映了股票市场总体价格水平及其变动趋势,包含了丰富的市场信息,受到投资者和政策制定者的普遍关注.利用一定的数学方法对其进行分析和研究,挖掘股指的潜在价值,对加快资本市场治理,提升金融效率,促进国民经济的平稳快速发展具有十分重要的意义.本文利用基于Takenaka-Malmquist自适应傅里叶分解(简称自适应傅里叶分解或AFD)的时频分布,有效提取了股票价格指数的时频特征,分析股票市场的变动趋势.为满足自适应傅里叶分解的要求,首先利用H-P滤波算法对时间序列进行预处理,去除时间序列的趋势项,然后利用AFD算法处理周期项数据,在此基础上得到股票价格指数的时频分布,并进一步分析股...
关键词 :
Takenaka-Malmquist系统 Takenaka-Malmquist系统 时频分布 时频分布 股票价格指数 股票价格指数 自适应傅里叶分解 自适应傅里叶分解
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GB/T 7714 | 陈维国 , 钱涛 , 李建平 et al. 基于Takenaka-Malmquist自适应时频分布的特征指标——来自上证和深证的数据 [J]. | 系统工程理论与实践 , 2020 , 40 (12) : 3112-3123 . |
MLA | 陈维国 et al. "基于Takenaka-Malmquist自适应时频分布的特征指标——来自上证和深证的数据" . | 系统工程理论与实践 40 . 12 (2020) : 3112-3123 . |
APA | 陈维国 , 钱涛 , 李建平 , 谢启伟 . 基于Takenaka-Malmquist自适应时频分布的特征指标——来自上证和深证的数据 . | 系统工程理论与实践 , 2020 , 40 (12) , 3112-3123 . |
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摘要 :
Casing shear deformation has become a serious problem in the development of shale gas fields, which is believed to be related to fault slipping caused by multistage fracturing, and the evaluation of the reduction of a casing's inner diameter is key. Although many fault slipping models have been published, most of them have not taken the fluid-solid-heat coupling effect into account, and none of the models could be used to calculate the reduction of a casing's inner diameter. In this paper, a new 3D finite element model was developed to simulate the progress of fault slipping, taking the fluid-solid-heat coupling effect during fracturing into account. For the purpose of increasing calculation accuracy, the elastoplastic constitutive relations of materials were considered, and the solid-shell elements technique was used. The reduction of the casing's inner diameter along the axis was calculated and the calculation results were compared with the measurement results of multi-finger caliper (MFC) surveys. A sensitivity analysis was conducted, and the influences of slip distance, casing internal pressure, thickness of production and intermediate casing, and the mechanical parameters of cement sheath on the reduction of a casing's inner diameter in the deformed segment were analyzed. The numerical analysis results showed that decreasing the slip distance, maintaining high pressure, decreasing the Poisson ratio of cement sheath, and increasing casing thickness were beneficial to protect the integrity of the casing. The numerical simulation results were verified by comparison to the shape of MFC measurement results, and had an accuracy up to 90.17%. Results from this study are expected to provide a better understanding of casing shear deformation, and a prediction method of a casing's inner diameter after fault slipping in multistage fracturing wells.
关键词 :
fluid-solid-heat coupling fluid-solid-heat coupling Multi Finger Caliper Multi Finger Caliper multistage fracturing multistage fracturing numerical simulation numerical simulation shear deformation shear deformation
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GB/T 7714 | Xi, Yan , Li, Jun , Liu, Gonghui et al. Mechanisms and Influence of Casing Shear Deformation near the Casing Shoe, Based on MFC Surveys during Multistage Fracturing in Shale Gas Wells in Canada [J]. | ENERGIES , 2019 , 12 (3) . |
MLA | Xi, Yan et al. "Mechanisms and Influence of Casing Shear Deformation near the Casing Shoe, Based on MFC Surveys during Multistage Fracturing in Shale Gas Wells in Canada" . | ENERGIES 12 . 3 (2019) . |
APA | Xi, Yan , Li, Jun , Liu, Gonghui , Li, Jianping , Jiang, Jiwei . Mechanisms and Influence of Casing Shear Deformation near the Casing Shoe, Based on MFC Surveys during Multistage Fracturing in Shale Gas Wells in Canada . | ENERGIES , 2019 , 12 (3) . |
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摘要 :
Path planning is an important research field in robotics, and it is also a key technology for realizing automatic navigation of aircraft. It is of great significance both in theory and in application. The task of planning trajectories for an aircraft has received considerable attention in the research literature. Most of the work assumes that the threat to the aircraft is static; less attention has been paid to the problem of the changing environment. However, the threat from the weather when the UAV is flying in the air is always changing. This paper introduces an improved BFS algorithm, which can find the best safe path when the threat is always changing. © The Authors, published by EDP Sciences, 2018.
关键词 :
Aircraft Aircraft Air navigation Air navigation Motion planning Motion planning Robot programming Robot programming Robots Robots
引用:
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GB/T 7714 | Li, Jianping , Shi, Yuliang . AUV path planning for environment changes over time [C] . 2018 . |
MLA | Li, Jianping et al. "AUV path planning for environment changes over time" . (2018) . |
APA | Li, Jianping , Shi, Yuliang . AUV path planning for environment changes over time . (2018) . |
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摘要 :
基于CAN总线技术和PIC单片机技术对四色胶印机的控制系统进行了研究.通过对胶印机的构造和工艺过程的研究,将控制系统划分为9个模块,根据实际要求设计了各模块的硬件电路,编写了系统的C语言程序.测试结果表明,系统具有良好的驱动性能,设计满足预期目标.
关键词 :
CAN总线 CAN总线 PIC单片机 PIC单片机 胶印机控制系统 胶印机控制系统
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GB/T 7714 | 王玉柱 , 张跃明 , 李建平 . 基于CAN总线的胶印机控制系统 [J]. | 仪表技术与传感器 , 2013 , (1) : 56-58 . |
MLA | 王玉柱 et al. "基于CAN总线的胶印机控制系统" . | 仪表技术与传感器 1 (2013) : 56-58 . |
APA | 王玉柱 , 张跃明 , 李建平 . 基于CAN总线的胶印机控制系统 . | 仪表技术与传感器 , 2013 , (1) , 56-58 . |
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摘要 :
以四色胶印机墨斗为平台,以PICl8F2580单片机为控制核心,设计了一套完整的直流电机闭环调速控制系统.详细设计了系统硬件电路,着重设计了与操作台和PC机通讯的CAN通讯接口电路、电机控制与驱动电路、电机位置闭环反馈电路和电机PWM调速电路,编写了系统的C语言驱动程序.经实验和实际环境下的运行证明,该系统具有良好的驱动性能、调速性能和抗电磁干扰性能,有利于降低成本,有利于国产胶印机的自动化、智能化进程,有良好的市场应用前景.
关键词 :
闭环控制 闭环控制 直流电动机 直流电动机 PWM调速 PWM调速 CAN总线 CAN总线
引用:
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GB/T 7714 | 李建平 , 张跃明 , 李太亮 . 基于PIC单片机的胶印机墨斗电机控制系统设计 [J]. | 包装工程 , 2011 , 32 (3) : 63-66,102 . |
MLA | 李建平 et al. "基于PIC单片机的胶印机墨斗电机控制系统设计" . | 包装工程 32 . 3 (2011) : 63-66,102 . |
APA | 李建平 , 张跃明 , 李太亮 . 基于PIC单片机的胶印机墨斗电机控制系统设计 . | 包装工程 , 2011 , 32 (3) , 63-66,102 . |
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摘要 :
The Si/SiGe/Si structures used in hetrojunction bipolar transistor (HBT) were grown by gas-source molecular beam epitaxy (GSMBE). The SiGe/Si HBT was fabricated with double mesa structure by using the emitter of 4 μm in width and 4 μm×18 μm in size. The current gain of 75 and fT of 20 GHz were obtained. The structure design, technology of material growth and fabrication of the HBT were described.
关键词 :
Double mesa structure; Gas-source molecular beam epitaxy; SiGe/Si heterojunction bipolar transistor Double mesa structure; Gas-source molecular beam epitaxy; SiGe/Si heterojunction bipolar transistor
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GB/T 7714 | Zou, D.-S. , Xu, C. , Chen, J.-X. et al. SiGe/Si material grown by GSMBE [J]. | Chinese Journal of Semiconductors , 2001 , 22 (8) : 1035-1037 . |
MLA | Zou, D.-S. et al. "SiGe/Si material grown by GSMBE" . | Chinese Journal of Semiconductors 22 . 8 (2001) : 1035-1037 . |
APA | Zou, D.-S. , Xu, C. , Chen, J.-X. , Shi, C. , Du, J.-Y. , Gao, G. et al. SiGe/Si material grown by GSMBE . | Chinese Journal of Semiconductors , 2001 , 22 (8) , 1035-1037 . |
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摘要 :
用GSMBE法生长了Si/SiGe/Si异质结构材料.采用双台面结构制造了SiGe/Si NPN异质结晶体管.在发射结条宽为4μm,面积为4μm×18μm的条件下,其共发射极直流放大倍数为75,截止频率为20GHz.给出了结构设计、材料生长和器件制作工艺.
关键词 :
气态源分子束外延 气态源分子束外延 双台面结构 双台面结构 Si/SiGe HBT Si/SiGe HBT
引用:
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GB/T 7714 | 邹德恕 , 徐晨 , 陈建新 et al. GSMBE生长的用于研制HBT的SiGe/Si异质结材料 [J]. | 半导体学报 , 2001 , 22 (8) : 1035-1037 . |
MLA | 邹德恕 et al. "GSMBE生长的用于研制HBT的SiGe/Si异质结材料" . | 半导体学报 22 . 8 (2001) : 1035-1037 . |
APA | 邹德恕 , 徐晨 , 陈建新 , 史辰 , 杜金玉 , 高国 et al. GSMBE生长的用于研制HBT的SiGe/Si异质结材料 . | 半导体学报 , 2001 , 22 (8) , 1035-1037 . |
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