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QSM-IDM -A novel quadrature spatial modulation based on interleaving division multiplexing for multiple antenna system 预览
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作者 Sherif K. El Dyasti Esam A.A. Hagras Hadia El-Hennawy 《数字通信与网络:英文版》 2019年第3期183-188,共6页
Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is t... Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is to extend the spatial constellation of the conventional Spatial Modulation (SM) in both the in-phase and quadrature components of the data symbol. In this paper, because QSM-based on Interleaxdng Division Multiplexing (IDM) has not been introduced in the literature as a multiple antenna system, we introduced a novel scheme, called QSM system based on Interleaving Division Multiplexing (QSM-IDM). The antenna sets are also applied to a spreader, before being used to assign an antenna number for information transmission. Analysis and simulations for a flat fading channel show that the proposed QSM-IDM method significantly outperforms the original QSM system with the same data rate, while maintaining a relatively acceptable complexity. The obtained simulation results show that the conducted analysis yields significant improvements for the accuracy of the proposed scheme, with satisfactory complexity. 展开更多
关键词 Interleaver DIVISION MULTIPLEXING (IDM) MULTIPLE Input MULTIPLE Output (MIMO) Spatial MODULATION (SM) QUADRATURE Spatial MODULATION (QSM)
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A novel modulation format identification based on amplitude histogram space
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作者 Tianliang WANG Xiaoying LIU 《中国光电子学前沿:英文版》 EI CSCD 2019年第2期190-196,共7页
In this paper, we proposed a novel modulation format identification method for square M-quadrature amplitude modulation (M-QAM) signals which is based on amplitude histogram space of the incoming data after analog-to-... In this paper, we proposed a novel modulation format identification method for square M-quadrature amplitude modulation (M-QAM) signals which is based on amplitude histogram space of the incoming data after analog-to-digital conversion, chromatic dispersion com-pensation at the receiver. We demonstrated the identifica-tion of quadrature phase-shift keying (QPSK), 16-QAM, 64-QAM formats with an amplitude histogram space. Simulation results show that it achieve 100% identification accuracy when the incoming signal OSNR is 14 dB to identify the modulation format of QPSK, 16-QAM, and 64-QAM signals in digital coherent systems. The method has low complexity and small delay. 展开更多
关键词 MODULATION FORMAT IDENTIFICATION (MFI) AMPLITUDE HISTOGRAM SPACE high-order MODULATION FORMAT optical performance monitoring
Analysis on FM-to-AM conversion of SSD beam induced by etalon effect in a high-power laser system
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作者 Ping Li Wei Wang +1 位作者 Jingqin Su Xiaofeng Wei 《高功率激光科学与工程:英文版》 CAS CSCD 2019年第2期5-10,共6页
FM-to-AM(frequency modulation-to-amplitude modulation)conversion caused by nonuniform spectral transmission of broadband beam is harmful to high-power laser facility.Smoothing by spectral dispersion(SSD)beam is a spec... FM-to-AM(frequency modulation-to-amplitude modulation)conversion caused by nonuniform spectral transmission of broadband beam is harmful to high-power laser facility.Smoothing by spectral dispersion(SSD)beam is a special broadband beam for its monochromatic feature at the given time and space on the near field.The traditional method which uses the optical spectral transfer function as filters cannot accurately describe its AM characteristics.This paper presents the theoretical analysis of the etalon effect for SSD beam.With a low-order approximation,the analytic model of the temporal shape of SSD beam is obtained for the first time,which gives the detailed AM characteristics at local and integral aspects,such as the variation of ripples width and amplitude in general situation.We also analyze the FM-to-AM conversion on the focal plane;in the focusing process,the lens simply acts as an integrator to smooth the AM of SSD beam.Because AM control is necessary for the near field to avoid optics damage and for the far field to ensure an optimal interaction of laser-target,our investigations could provide some important phenomena and rules for pulse shape control. 展开更多
关键词 amplitude MODULATION ETALON EFFECT frequency MODULATION HIGH-POWER laser SMOOTHING by spectral dispersion
Optoelectronic properties analysis of silicon light-emitting diode monolithically integrated in standard CMOS IC
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作者 陈彦旭 许栋梁 +6 位作者 徐开凯 张宁 刘斯扬 赵建明 罗谦 Lukas W.Snyman Jacobus W.Swart 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期115-120,共6页
Si p^+n junction diodes operating in the mode of avalanche breakdown are capable of emitting light in the visible range of 400-900 nm. In this study, to realize the switching speed in the GHz range, we present a trans... Si p^+n junction diodes operating in the mode of avalanche breakdown are capable of emitting light in the visible range of 400-900 nm. In this study, to realize the switching speed in the GHz range, we present a transient model to shorten the carrier lifetime in the high electric field region by accumulating carriers in both p and n type regions. We also verify the optoelectronic characteristics by disclosing the related physical mechanisms behind the light emission phenomena. The emission of visible light by a monolithically integrated Si diode under the reverse bias is also discussed. The light is emitted as spatial sources by the defects located at the p-n junction of the reverse-biased diode. The influence of the defects on the electrical behavior is manifested as a current-dependent electroluminescence. 展开更多
关键词 SILICON LIGHT-EMITTING DIODE REVERSE BIAS ELECTRO-OPTIC modulation
Dynamics of InAs/GaAs quantum dot lasers epitaxially grown on Ge or Si substrate 预览
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作者 Cheng Wang Yueguang Zhou 《半导体学报:英文版》 EI CAS CSCD 2019年第10期74-84,共11页
Growing semiconductor laser sources on silicon is a crucial but challenging technology for developing photonic integrated circuits(PICs).InAs/GaAs quantum dot(Qdot)lasers have successfully circumvented the mismatch pr... Growing semiconductor laser sources on silicon is a crucial but challenging technology for developing photonic integrated circuits(PICs).InAs/GaAs quantum dot(Qdot)lasers have successfully circumvented the mismatch problem betweenⅢ–Ⅴmaterials and Ge or Si,and have demonstrated efficient laser emission.In this paper,we review dynamical characteristics of Qdot lasers epitaxially grown on Ge or Si,in comparison with those of Qdot lasers on native GaAs substrate.We discuss properties of linewidth broadening factor,laser noise and its sensitivity to optical feedback,intensity modulation,as well as mode locking operation.The investigation of these dynamical characteristics is beneficial for guiding the design of PICs in optical communications and optical computations. 展开更多
关键词 quantum DOT LASER LASER noise modulation DYNAMICS mode LOCKING PHOTONIC integrated circuits
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Modulation Effects of the 3D Strain Microenvironment on Characteristics of Mesenchymal Stem Cell-Derived Exosomes
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作者 Yufei Ma Wenting Yu Feng Xu 《医用生物力学》 CAS CSCD 北大核心 2019年第A01期128-129,共2页
It is necessary to investigate the characteristics of Mesenchymal stem cells(MSCs)derived exosomes,and especially their application in tissue regeneration.Previous studies have shown that inflammatory stimulation enha... It is necessary to investigate the characteristics of Mesenchymal stem cells(MSCs)derived exosomes,and especially their application in tissue regeneration.Previous studies have shown that inflammatory stimulation enhanced the secretion of MSC-derived exosomes with stronger anti-inflammatory protein,cytokine profiles,and functional RNA via altering COX2/PGE2 pathway.Recently,accumulating evidence has also revealed that biophysical cues(especially biomechanical cues)in cell microenvironment have significant effects not only on cells but also on their exosomes.It has been reported that applying bi-axial strain to MSCs induces formation of a stiffer cytoskeleton through mTORC2 signaling,which biases against adipogenic differentiation and toward osteoblastogenesis.At the same time,For example,dimensionality,composition and stiffness of the extracellular matrix(ECM)has been proved to affect the size and composition of exosomes secreted by cancer cells.However,the effects of biomechanical cues in the three-dimensional(3D)microenvironment on stem cell-derived exosomes remains to be unveiled.Therefore,it is important to understand the roles of 3D cell mechanical microenvironment in regulating the characteristics of stem cell-derived exosomes and develop more efficient approaches to enhance their functions.This study aimed to explore the changes in characteristics of exosomes secreted by MSCs in periodontium in response to the matrix strain in 3D.Periodontal ligament stem cells(PDLSCs)were cultured in a 3D strain microenvironment engineered with microscale magnetically stretched collagen hydrogels.The morphology,particle distribution,marker protein expression of PDLSC-derived exosomes were analyzed.Then the pro-osteogenic property of exosomes was evaluated by assessing cell viability,proliferation,migration and osteogenic differentiation of target cells,for instance human bone marrow mesenchymal stem cells(hBMSCs).Detailed characterizations revealed that PDLSC-derived exosomes in the 3D strain mi-croenvironment were with s 展开更多
关键词 Modulation Effects the 3D STRAIN MICROENVIRONMENT CHARACTERISTICS Mesenchymal Stem Cell-Derived EXOSOMES
A tightly coupled rotational SINS/CNS integrated navigation method for aircraft 预览
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作者 NING Xiaolin YUAN Weiping LIU Yanhong 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第4期770-782,共13页
Strapdown inertial navigation system(SINS)/celestial navigation system(CNS)integrated navigation is widely used to achieve long-time and high-precision autonomous navigation for aircraft.In general,SINS/CNS integrated... Strapdown inertial navigation system(SINS)/celestial navigation system(CNS)integrated navigation is widely used to achieve long-time and high-precision autonomous navigation for aircraft.In general,SINS/CNS integrated navigation can be divided into two integrated modes:loosely coupled integrated navigation and tightly coupled integrated navigation.Because the loosely coupled SINS/CNS integrated system is only available in the condition of at least three stars,the latter one is becoming a research hotspot.One major challenge of SINS/CNS integrated navigation is obtaining a high-precision horizon reference.To solve this problem,an innovative tightly coupled rotational SINS/CNS integrated navigation method is proposed.In this method,the rotational SINS error equation in the navigation frame is used as the state model,and the starlight vector and star altitude are used as measurements.Semi-physical simulations are conducted to test the performance of this integrated method.Results show that this tightly coupled rotational SINS/CNS method has the best navigation accuracy compared with SINS,rotational SINS,and traditional tightly coupled SINS/CNS integrated navigation method. 展开更多
关键词 celestial navigation system(CNS) rotation modulation technology rotational strapdown inertial navigation system(SINS) rotational SINS/CNS integrated navigation
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低功耗数字化调制解调平台的设计与实现 预览
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作者 周士雷 韩刚 《无线电工程》 2019年第2期123-127,共5页
针对卫星通信信道设备低功耗和数字化的需求,提出一种低功耗、数字化卫星调制解调平台的设计方法。前端通过AD9364完成模拟信号和数字信号的转换,后端采用大规模FPGA进行数字信号处理。测试结果表明,该调制解调平台通过加载不同的软件,... 针对卫星通信信道设备低功耗和数字化的需求,提出一种低功耗、数字化卫星调制解调平台的设计方法。前端通过AD9364完成模拟信号和数字信号的转换,后端采用大规模FPGA进行数字信号处理。测试结果表明,该调制解调平台通过加载不同的软件,可实现数据速率可变、调制解调方式可变、多种编译码方式、扩展L频段(950~2150MHz),大幅度降低了平台的体积和功耗,可作为一个成熟平台应用于卫星通信终端或便携站的产品设计中。 展开更多
关键词 小型化 调制 解调 数据速率可变 扩展L频段
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光电技术在轨道交通测量中的应用研究 预览
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作者 田波 祁艳艳 +1 位作者 魏琳 饶晓红 《自动化仪表》 CAS 2019年第7期57-59,共3页
随着社会的不断进步,当前城市轨道交通发展迅速,城市轨道交通安全性和稳定性要求越来越高。同时,计算机技术与微电子技术的快速发展,为轨道交通测量工作效率的提升带来了巨大的推动力。通过对光电技术在轨道交通测量中的应用原理进行分... 随着社会的不断进步,当前城市轨道交通发展迅速,城市轨道交通安全性和稳定性要求越来越高。同时,计算机技术与微电子技术的快速发展,为轨道交通测量工作效率的提升带来了巨大的推动力。通过对光电技术在轨道交通测量中的应用原理进行分析,通过光电技术对轨距、高低和障碍物等进行测量,并将测量值通过计算机控制进行调制、放大以及解调工作后输出测量值。计算机在得到测量值后,通过计算确定了当前技术参数,并进行了详细分析,以采取有效的措施来提高其测量效果。光电技术是轨道交通智能化技术的主要内容之一,其应用研究对传统轨道交通测量质量与效率的提升均具有重要意义。应用光电技术后在测量过程中可有效减少人为因素造成的误差,同时也大大降低了人工成本。 展开更多
关键词 轨道交通 光电技术 安全性 调制 解调 智能化
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雷达信号的数字化中频调制解调算法仿真 预览
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作者 赵玲峰 《计算机仿真》 北大核心 2019年第6期16-20,共5页
研究一种有效的雷达数字化中频信号的调制解调算法对卫星探测、航空航天、海上救援等工作具有重要意义。针对当前算法存在雷达数字化中频信号解调结果失真严重,误比特率较大、抗干扰性不强的问题,提出一种基于DSP的雷达数字化中频信号... 研究一种有效的雷达数字化中频信号的调制解调算法对卫星探测、航空航天、海上救援等工作具有重要意义。针对当前算法存在雷达数字化中频信号解调结果失真严重,误比特率较大、抗干扰性不强的问题,提出一种基于DSP的雷达数字化中频信号解调算法,通过对雷达中频信号数字化处理和展开,分别利用单音信号对雷达数字化中频信号进行调幅和调频,同时给出了能够实现雷达数字化中频信号的正交调制的条件,实现了信号调制。在上述获得雷达数字化中频信号调制结果的基础上,利用相干解调方法将调制信号与余弦载波信号和正弦载波信号分别相乘,并将其中关于高频信号的成分进行过滤获得解调后的信息码。为了改善原有解调算法存在的问题,对输入的初步解调后的雷达中频模拟信号进行采样,在综合考虑实际电路的可行性和解调算法的可行性条件下,对中频信号进行进一步数字化处理并做DCT变换。根据变换后雷达数字化中频信号所具有的特点解调出原始信号波形,完成解调。仿真结果表明,所提方法具有较强的抗干扰性能,解调结果只有微小失真,基本能够满足实际应用要求,且误比特率较小。 展开更多
关键词 雷达信号 数字化 中频信号 调制 解调
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Influence of random phase modulation on the imaging quality of computational ghost imaging
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作者 高超 王晓茜 +3 位作者 蔡宏吉 任捷 刘籍元 姚治海 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第2期77-81,共5页
In this paper, we investigated phase modulation-based computational ghost imaging. According to the results of numerical simulations, we found that the range of the random phase affects the quality of the reconstructe... In this paper, we investigated phase modulation-based computational ghost imaging. According to the results of numerical simulations, we found that the range of the random phase affects the quality of the reconstructed image. Besides,compared with those amplitude modulation-based computational ghost imaging schemes, introducing random phase modulation into the computational ghost imaging scheme could significantly improve the spatial resolution of the reconstructed image, and also extend the field of view. 展开更多
关键词 COMPUTATIONAL GHOST IMAGING RANDOM PHASE MODULATION IMAGING quality
The hypothalamic-spinal dopaminergic system:a target for pain modulation 预览
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作者 Michelino Puopolo 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第6期925-930,共6页
Nociceptive signals conveyed to the dorsal horn of the spinal cord by primary nociceptors are subject to extensive modulation by local neurons and by supraspinal descending pathways to the spinal cord before being rel... Nociceptive signals conveyed to the dorsal horn of the spinal cord by primary nociceptors are subject to extensive modulation by local neurons and by supraspinal descending pathways to the spinal cord before being relayed to higher brain centers.Descending modulatory pathways to the spinal cord comprise,among others,noradrenergic,serotonergic,γ-aminobutyric acid(GABA)ergic,and dopaminergic fibers.The contributions of noradrenaline,serotonin,and GABA to pain modulation have been extensively investigated.In contrast,the contributions of dopamine to pain modulation remain poorly understood.The focus of this review is to summarize the current knowledge of the contributions of dopamine to pain modulation.Hypothalamic A11 dopaminergic neurons project to all levels of the spinal cord and provide the main source of spinal dopamine.Dopamine receptors are expressed in primary nociceptors as well as in spinal neurons located in different laminae in the dorsal horn of the spinal cord,suggesting that dopamine can modulate pain signals by acting at both presynaptic and postsynaptic targets.Here,I will review the literature on the effects of dopamine and dopamine receptor agonists/antagonists on the excitability of primary nociceptors,the effects of dopamine on the synaptic transmission between primary nociceptors and dorsal horn neurons,and the effects of dopamine on pain in rodents.Published data support both anti-nociceptive effects of dopamine mediated by D2-like receptors and pro-nociceptive effects mediated by D1-like receptors. 展开更多
关键词 A11 nucleus DESCENDING modulation dopamine DORSAL horn DORSAL root GANGLIA D2 RECEPTORS D1 RECEPTORS NOCICEPTORS pain SPINAL cord
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Weakly-coupled mode division multiplexing over conventional multi-mode fiber with intensity modulation and direct detection
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作者 Juhao LI Zhongying WU +7 位作者 Dawei GE Jinglong ZHU Yu TIAN Yichi ZHANG Jinyi YU Zhengbin LI Zhangyuan CHEN Yongqi HE 《中国光电子学前沿:英文版》 EI CSCD 2019年第1期31-40,共10页
Multi-mode fiber(MMF)links are expected to greatly enhance capacity to cope with rapidly increasing data traffic in optical short-reach systems and networks.Recently,mode division multiplexing(MDM)over MMF has been pr... Multi-mode fiber(MMF)links are expected to greatly enhance capacity to cope with rapidly increasing data traffic in optical short-reach systems and networks.Recently,mode division multiplexing(MDM)over MMF has been proposed,in which different modes in MMF are utilized as spatial channels for data transmission.Stronglycoupled MDM techniques utilizing coherent detection and multiplex-input-multiplex-output(MIMO)digital signal processing(DSP)are complex and expensive for shortreach transmission.So the weakly-coupled approach by significantly suppressing mode coupling in the fiber and optical components has been proposed.In this way,the signals in each mode can be independently transmitted and received using conventional intensity modulation and direct detection(IM-DD).In this paper,we elaborate the key technologies to realize weakly-coupled MDM transmission over conventional MMF,including mode characteristic in MMF and weakly-coupled mode multiplexer/ demultiplexer(MUX/DEMUX).We also present the upto-date experimental results for weakly-coupled MDM transmission over conventional OM3 MMF.We show that weakly-coupled MDM scheme is promising for high-speed optical interconnections and bandwidth upgrade of already-deployed MMF links. 展开更多
关键词 MULTI-MODE FIBER (MMF) MODE DIVISION MULTIPLEXING (MDM) weak MODE coupling intensity modulation and direct detection (IM-DD)
Interpersonal skills and emotion management:Impact of social leadership on job satisfaction of workers 预览
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作者 Allan Phiri Najma Bano Amtul Raouf 《发展与教育心理学进展(英文)》 2019年第1期1-6,共6页
Psychological cognition is an important aspect in human psychology and management. This article is aimed to look at interpersonal emotional management interpersonal emotion management as a theoretical important indica... Psychological cognition is an important aspect in human psychology and management. This article is aimed to look at interpersonal emotional management interpersonal emotion management as a theoretical important indicator of job satisfaction. The main discussion is on how to predict employees’ job satisfaction through the implementation of interpersonal emotion management strategies and the main source of research is review of existing literature. This review addresses the gap in the literature by reviewing the role of interpersonal emotional management on followers’ job performance. This review finds the relationship between interpersonal emotional management which consists of four dimensions: circumstance adjustment,attentional placement,cognitive change,modulation of emotional response and job satisfaction. Overall,this literature review contributes to the interpersonal emotion management and job satisfaction literatures by providing meaningful management implications to the organizations. 展开更多
关键词 circumstance adjustment attentional PLACEMENT COGNITIVE change modulation of EMOTIONAL response and JOB SATISFACTION
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双三相永磁同步电机在电动汽车中的应用研究 预览
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作者 蔡萍 李永岗 赵赫 《微特电机》 2019年第1期59-62,69共5页
针对电动汽车续航能力、运行工况复杂、高可靠性运行等要求,以相移30°双三相永磁同步电机为研究对象,对电动汽车驱动系统特性展开讨论,包括基于空间矢量解耦的数学模型,空间矢量调制技术以及基于转子磁场定向的矢量控制、无速度传... 针对电动汽车续航能力、运行工况复杂、高可靠性运行等要求,以相移30°双三相永磁同步电机为研究对象,对电动汽车驱动系统特性展开讨论,包括基于空间矢量解耦的数学模型,空间矢量调制技术以及基于转子磁场定向的矢量控制、无速度传感器等方面,弥补了传统三相驱动系统存在的劣势,给出了适用于电动汽车的高效率、快响应、高可靠性的双三相永磁同步电机驱动系统的解决方案。 展开更多
关键词 双三相永磁同步电机 空间矢量脉宽调制 调制技术 矢量控制 无速度传感器控制
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Evolution of incommensurate superstructure and electronic structure with Pb substitution in(Bi2-xPbx)Sr2CaCu2O8+δ superconductors
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作者 刘静 赵林 +24 位作者 高强 艾平 张璐 谢涛 黄建伟 丁颖 胡成 闫洪涛 宋春尧 徐煜 李聪 蔡永青 戎洪涛 吴定松 刘国东 王庆艳 黄元 张丰丰 杨峰 彭钦军 李世亮 杨槐馨 李建奇 许祖彦 周兴江 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期102-110,共9页
High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized ... High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized by transmission electron microscope(TEM) and measured by high resolution laser-based angle-resolved photoemission spectroscopy(ARPES) with different photon energies.A systematic evolution of the electronic structure and superstructure with Pb substitution has been revealed for the first time.The superstructure shows a significant change with Pb substitution and the incommensurate modulation vector(Q) decreases with increasing Pb substitution.In the meantime, the superstructure intensity from ARPES measurements also decreases dramatically with increasing Pb concentration.The superstructure in Bi2212 can be effectively suppressed by Pb substitution and it nearly disappears with a Pb substitution of x = 0.8.We also find that the superstructure bands in ARPES measurements depend sensitively on the photon energy of lasers used;they can become even stronger than the main band when using a laser photon energy of 10.897 eV.These results provide important information on the origin of the incommensurate superstructure and its control and suppression in bismuth-based high temperature superconductors. 展开更多
关键词 Bi2-xPbxSr2CaCu2O8+δ SUPERSTRUCTURE electronic structure angle-resolved PHOTOEMISSION spectroscopy(ARPES) modulation
某机载雷达电信号异常调制的故障分析及设计改进 预览
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作者 王晓红 于坤鹏 董好志 《电子机械工程》 2019年第4期11-13,51共4页
某机载雷达在试飞联调时,电信号中出现了固定频率的异常调制信号,影响到电性能。根据故障仅发生在振动环境下这一事实,得出异常调制与振动相关的初步结论。通过对雷达各主要组成部件的分析,发现天线单元固有频率与调制频率吻合的概率最... 某机载雷达在试飞联调时,电信号中出现了固定频率的异常调制信号,影响到电性能。根据故障仅发生在振动环境下这一事实,得出异常调制与振动相关的初步结论。通过对雷达各主要组成部件的分析,发现天线单元固有频率与调制频率吻合的概率最高。对单元开展仿真分析和试验验证,得出最终结论:天线单元的固有频率落在载机随机振动的第1个高量级窄带内,从而引起电信号出现异常调制现象。对天线单元进行了设计改进,使其固有频率远离高能量窄带,电信号恢复正常。 展开更多
关键词 机载雷达 天线 调制 正弦扫频 随机振动
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光通信网络的信号检波调制算法设计
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作者 蒙芳 樊国根 《电子测量技术》 2019年第12期81-85,共5页
为了提高光通信网络的输出质量,降低输出误码,提出一种基于时频联合特征分解的光通信网络信号检波调制算法。首先构建光通信网络的传输信道模型,进行光通信网络传输信号采样,对采集的信号采用时频分解方法实现信号从时域向频域转换,提... 为了提高光通信网络的输出质量,降低输出误码,提出一种基于时频联合特征分解的光通信网络信号检波调制算法。首先构建光通信网络的传输信道模型,进行光通信网络传输信号采样,对采集的信号采用时频分解方法实现信号从时域向频域转换,提取信号的包络幅值特征量,根据光通信网络传输信号的包络幅值响应进行自适应检波处理,对光通信网络采用反馈调制方法进行信道均衡设计,采用时频联合特征分解方法实现信号的滤波检测和检波调制。仿真结果表明,采用该方法进行光通信网络的信号检波调制能提高信号的均衡传输性能,光通信网络的输出误码较低,提高了网络通信质量。 展开更多
关键词 光通信网络 信号 检波 调制 误码率
用于HART仪表的FSK阶梯波发送电路设计 预览
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作者 辛晓宁 范超 +1 位作者 任建 刘斌 《沈阳工业大学学报》 CAS 北大核心 2019年第2期169-173,共5页
针对以往HART仪表FSK发送电路功耗大且电路复杂的问题,提出了一种新型的应用在HART仪表上的FSK信号发送电路.该电路采用一种新型频率合成算法,即阶梯波产生算法,用来产生连续相位的温度码,然后将温度码送入DAC输出FSK阶梯波.结果表明,... 针对以往HART仪表FSK发送电路功耗大且电路复杂的问题,提出了一种新型的应用在HART仪表上的FSK信号发送电路.该电路采用一种新型频率合成算法,即阶梯波产生算法,用来产生连续相位的温度码,然后将温度码送入DAC输出FSK阶梯波.结果表明,该电路能够产生连续相位的FSK信号阶梯波,功耗为0. 14 mA,失真度为3%,信噪比为92 d B,频率误差为1‰.该电路与同类产品相比,不仅能够产生连续相位的FSK阶梯波,而且电路简单,具有较高的性能. 展开更多
关键词 频移键控 调制 连续相位 频率误差 阶梯波 温度码 数模转换 低功耗
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某型模块化高速路轨两用装置 预览
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作者 许创 胡松松 张勇 《工程机械》 2019年第5期7-11,6共6页
基于对当前路轨两用车的需求分析,设计了某型模块化高速路轨两用装置。针对泵及马达排量采用分阶段顺序控制方法,实现启动大转矩,高速小流量的效果,达到便于配套、节能环保、空间紧凑及降低成本的目的。通过采集及处理行车制动气路的压... 基于对当前路轨两用车的需求分析,设计了某型模块化高速路轨两用装置。针对泵及马达排量采用分阶段顺序控制方法,实现启动大转矩,高速小流量的效果,达到便于配套、节能环保、空间紧凑及降低成本的目的。通过采集及处理行车制动气路的压力信息,实现公路、铁路两种行驶模式的制动操作统一,提高了行驶安全性;借助有限元分析和参照相关标准,对主要结构件强度和配装车辆的动力学参数进行校核计算;通过设计的轮轴转速控制试验系统,对装置的主要性能指标进行了验证。验证结果表明,该装置的各动作逻辑准确,主要性能参数满足设计要求,轨道最高行驶速度达到70 km/h。 展开更多
关键词 路轨两用车 模块化 功能切换 动力学 安全性
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