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Influence of random phase modulation on the imaging quality of computational ghost imaging 被引量:4
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作者 Chao Gao Xiao-Qian Wang +3 位作者 Hong-Ji Cai Jie Ren Ji-Yuan Liu Zhi-Hai Yao 《Chinese Physics B》 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
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Modulation instabilities in randomly birefringent two-mode optical fibers
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作者 李金花 任海东 +2 位作者 裴世鑫 曹兆楼 咸冯林 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第12期283-293,共11页
Modulation instabilities in the randomly birefringent two-mode optical fibers (RB-TMFs) are analyzed in detail by accounting the effects of the differential mode group delay (DMGD) and group velocity dispersion (... Modulation instabilities in the randomly birefringent two-mode optical fibers (RB-TMFs) are analyzed in detail by accounting the effects of the differential mode group delay (DMGD) and group velocity dispersion (GVD) ratio between the two modes, both of which are absent in the randomly birefringent single-mode optical fibers (RB-SMFs). New MI characteristics are found in both normal and anomalous dispersion regimes. For the normal dispersion, without DMGD, no MI exists. With DMGD, a completely new MI band is generated as long as the total power is smaller than a critical total power value, named by Per, which increases significantly with the increment of DMGD, and reduces dramatically as GVD ratio and power ratio between the two modes increases. For the anomalous dispersion, there is one MI band without DMGD. In the presence of DMGD, the MI gain is reduced generally. On the other hand, there also exists a critical total power (Per), which increases (decreases) distinctly with the increment of DMGD (GVD ratio of the two modes) but varies complicatedly with the power ratio between the two modes. Two MI bands are present for total power smaller than Per, and the dominant band can be switched between the low and high frequency bands by adjusting the power ratio between the two modes. The M1 analysis in this paper is verified by numerical simulation. 展开更多
关键词 modulation instability Manakov equations two-mode optical fibers random birefringence
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Suppression of Soliton Timing Jitters in Fibers with Random Birefringence by Periodical Polarization Modulation
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作者 CHEN Wei-cheng XU Wen-cheng 《Semiconductor Photonics and Technology》 CAS 2006年第4期224-227,237,共5页
Periodical polarization modulation scheme is proposed to suppress timing jitters induced by frequency fluctuations between two polarization components of solitons. In periodical polarization modulation scheme, the pol... Periodical polarization modulation scheme is proposed to suppress timing jitters induced by frequency fluctuations between two polarization components of solitons. In periodical polarization modulation scheme, the polarization states of the soliton are modulated to excite equally for suppressing timing jitters induced by two unequal polarization components in the soliton trapping. Moreover, polarization modulation can weaken the effect of random birefringence on the soliton pulses in each relay distance. The numerical result shows that the soliton timing jitters are suppressed by our proposed method. 展开更多
关键词 Timing jitter random birefringence Polarization modulation SOLITON
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Arbitrary topological charge vortex beams from carbon dots random lasers 被引量:3
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作者 Xiang-Dong Wang Xiao-Bo Mi +6 位作者 Jiu-Ru He Feng-Ying Ma Jun-Qiao Wang Li Song Yong-Qiang Zhang Si-Yu Lu Yong-Sheng Hu 《Rare Metals》 SCIE EI CAS CSCD 2024年第8期3844-3853,共10页
Vortex beams have attracted great attention due to their promising applications in the fields of high-capacity optical communication,optical micromanipulation,and quantum information processing.Here,we demonstrate vor... Vortex beams have attracted great attention due to their promising applications in the fields of high-capacity optical communication,optical micromanipulation,and quantum information processing.Here,we demonstrate vortex beams with flexible control of the topological charge and modes in a carbon dots random laser for the first time.Vortex beams with different types,including the Laguerre-Gaussian(LG),Bessel-Gaussian(BG),LG-superposition,and polarized vortex beams with topological charges up to 50,have been successfully achieved.Moreover,vortex beams can be well realized in carbon dots random lasers with different emission wavelengths covering from 465 to 612 nm.This work would not only enrich the types of vortex laser,especially for solution-processable lasers,but also provide a new route to realizing multicolor and wavelength-tunable vortex lasers. 展开更多
关键词 Carbon dots random lasers Vortex beam Topological charge Spatial light modulator
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基于FSM实现随机空间电压矢量PWM的新策略
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作者 刘佳宇 袁秀湘 《电力电子技术》 CSCD 北大核心 2006年第3期36-38,共3页
提出一种新的随机空间矢量PWM调制策略,通过有限状态机(FiniteStateMachine,FSM)形成空间矢量PWM过程,实现有限状态之间的随机转换,从而对电压空间矢量进行随机调制。将该策略由两电平推广到三电平,发展了基于该策略的多电平随机空间矢... 提出一种新的随机空间矢量PWM调制策略,通过有限状态机(FiniteStateMachine,FSM)形成空间矢量PWM过程,实现有限状态之间的随机转换,从而对电压空间矢量进行随机调制。将该策略由两电平推广到三电平,发展了基于该策略的多电平随机空间矢量PWM方法。这种随机调制策略易于提高开关频率相结合,适合于数字实现。仿真和实验结果证明,这种随机空间矢量PWM策略是有效可行的。 展开更多
关键词 脉宽调制 随机控制/有限状态机 空间欠量脉宽调制 可编程逻辑器件
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Small-Scale CMOS Pseudo SRAM Module Design
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作者 李昀 刘振宇 韩月秋 《Journal of Beijing Institute of Technology》 EI CAS 2004年第2期127-130,共4页
An approach to design small scale CMOS static random access memory (SRAM) is proposed. The design of address decoder, memory cell, and the layout are included. This approach adopts flip-flop array structure. The flip-... An approach to design small scale CMOS static random access memory (SRAM) is proposed. The design of address decoder, memory cell, and the layout are included. This approach adopts flip-flop array structure. The flip-flops are used as the storage cells and they are stacked to form the whole SRAM module. The word select bit is generated from the address decoder. And one word at a time is selected for reading or writing. The design of the memory core's layout is also discussed since it should be optimized to save area and also should be convenient for realization. It's a full-custom layout. The address decoder is composed of combinational logic circuit and its layout is also designed as a full-custom layout. With all these modules, the integral structure of the SRAM is carried out. 展开更多
关键词 static random access memory (SRAM) memory core address decoder layout module design
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L^0-CONVEX COMPACTNESS AND RANDOM NORMAL STRUCTURE IN L^0(F,B)
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作者 Tiexin GUO Erxin ZHANG +1 位作者 Yachao WANG George YUAN 《Acta Mathematica Scientia》 SCIE CSCD 2020年第2期457-469,共13页
Let(B,||·||)be a Banach space,(?,F,P)a probability space,and L^0(F,B)the set of equivalence classes of strong random elements(or strongly measurable functions)from(?,F,P)to(B,||·||).It is well known that L^0... Let(B,||·||)be a Banach space,(?,F,P)a probability space,and L^0(F,B)the set of equivalence classes of strong random elements(or strongly measurable functions)from(?,F,P)to(B,||·||).It is well known that L^0(F,B)becomes a complete random normed module,which has played an important role in the process of applications of random normed modules to the theory of Lebesgue-Bochner function spaces and random operator theory.Let V be a closed convex subset of B and L^0(F,V)the set of equivalence classes of strong random elements from(?,F,P)to V.The central purpose of this article is to prove the following two results:(1)L^0(F,V)is L^0-convexly compact if and only if V is weakly compact;(2)L^0(F,V)has random normal structure if V is weakly compact and has normal structure.As an application,a general random fixed point theorem for a strong random nonexpansive operator is given,which generalizes and improves several well known results.We hope that our new method,namely skillfully combining measurable selection theorems,the theory of random normed modules,and Banach space techniques,can be applied in the other related aspects. 展开更多
关键词 Complete random normed modules fixed point theorem L^0-convex compactness random normal structure random nonexpansive operators
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Efficacy of a Novel Antibody TLR3 Modulator in the Self-Treatment of Common Cold: The ESTUAR Trial
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作者 Andrey Martyushev-Poklad Jacques Bruhwyler +1 位作者 Stéphane Heijmans Michel Thiry 《Advances in Infectious Diseases》 2015年第4期204-217,共14页
Context: Since the discovery of toll-like receptor 3 (TLR3), no specific tools have been developed to modulate its activity in upper respiratory tract viral infections (URTIs). ContafluTM (antibodies to TLR3 cytoplasm... Context: Since the discovery of toll-like receptor 3 (TLR3), no specific tools have been developed to modulate its activity in upper respiratory tract viral infections (URTIs). ContafluTM (antibodies to TLR3 cytoplasmic fragment) is the first specific TLR3 modulator that showed efficacy in a mouse model of influenza. Objective: To evaluate the efficacy of Contaflu in URTI. Methods: A double-blind randomized placebo-controlled trial in adults with self-reported URTI (the ESTUAR trial) was conducted in 2012/2013 in Belgium. Adult outpatients started a 7-day treatment course with oral tablets of Contaflu or placebo within 36 h after onset of at least one of 4 typical symptoms of URTI. Patients were examined twice by their general practitioners, on days 2-3 and 10-14 after start of treatment. The primary endpoint was the overall severity of URTI calculated as the sum of Wisconsin Upper Respiratory Symptom Survey (WURSS-21) scores over the follow-up. Independent Student’s t test was used to compare the disease severity between groups. Results: A total of 243 patients were enrolled by 32 investigators (121 Contaflu, 122 placebo);92% of cases matched ICD codes J00 or J06. Most patients had very mild (41.8%) or mild (18.2%) URTI symptoms. In the ITT cohort, neither primary nor secondary outcome measures (duration of URTI, day-to-day and overall functional impairments) showed statistically significant differences between groups. The rate of adverse events was similar in both groups. In patients with moderate to severe URTI symptoms, Contaflu tended to reduce the overall disease severity, daily symptoms, and to improve the functional state. Due to the small size of the corresponding subgroups, Contaflu efficacy on daily scores was statistically significant (p < 0.05) only 1, 2, and 5 days after start of treatment. Conclusion: Contaflu was ineffective in mild URTI and showed efficacy in moderate to severe URTI cases. 展开更多
关键词 Common Cold TREATMENT TOLL-LIKE Receptor 3 TLR3 modulation randomIZED Clinical TRIAL
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基于PRBS的中压直流系统宽频阻抗测量装置及其控制 被引量:2
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作者 季振东 朱述超 +3 位作者 许光强 王建华 赵剑锋 肖小龙 《电力系统自动化》 北大核心 2025年第9期199-207,共9页
随着直流系统中电力电子化程度的加深,电力电子装置的端口阻抗特性对系统稳定性产生了一定影响。为了获取中压直流系统的阻抗特性用以评估系统稳定性,文中对宽频阻抗测量装置展开了研究。首先,以伪随机二进制序列(PRBS)作为输出扰动测... 随着直流系统中电力电子化程度的加深,电力电子装置的端口阻抗特性对系统稳定性产生了一定影响。为了获取中压直流系统的阻抗特性用以评估系统稳定性,文中对宽频阻抗测量装置展开了研究。首先,以伪随机二进制序列(PRBS)作为输出扰动测量信号,提出了一种混合子模块级联多电平拓扑的阻抗测量装置;然后,在此基础上提出了基于子模块分类的集中式调制方法,通过子模块4种工作模式的划分和配合来实现PRBS信号的高质量输出,实现子模块电容电压均衡,有利于降低开关损耗,并设计了相关主电路参数的计算原则。最后,硬件在环仿真结果验证了所提控制方法的有效性,表明所提阻抗测量装置具备良好的输出效果,能够在满足阻抗测量需求的前提下提高测量效率。 展开更多
关键词 中压直流系统 阻抗测量 伪随机二进制序列(PRBS) 级联多电平拓扑 集中式调制 混合子模块 电容均压
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Group Action on Fuzzy Modules
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作者 Mohammad Yamin Poonam Kumar Sharma 《Applied Mathematics》 2016年第5期413-421,共9页
In this article, we introduce the notion of fuzzy G-module by defining the group action of G on a fuzzy set of a Z-module M. We establish the cases in which fuzzy submodules also become fuzzy G-submodules. Notions of ... In this article, we introduce the notion of fuzzy G-module by defining the group action of G on a fuzzy set of a Z-module M. We establish the cases in which fuzzy submodules also become fuzzy G-submodules. Notions of a fuzzy prime submodule, fuzzy prime G-submodule, fuzzy semi prime submodule, fuzzy G-semi prime submodule, G-invariant fuzzy submodule and G-invariant fuzzy prime submodule of M are introduced and their properties are described. The homomorphic image and pre-image of fuzzy G-submodules, G-invariant fuzzy submodules and G-invariant fuzzy prime submodules of M are also established. 展开更多
关键词 Fuzzy Submodule (fsm) Fuzzy Prime Submodule (FPSM) Fuzzy Semi Prime Submodule Group Action (FSPSM) G-Invariant Submodule G-module Homomorphism
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Unveiling optical rogue wave behavior with temporally localized structures in Brillouin random fiber laser comb
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作者 Yuxi Pang Qiang Ji +6 位作者 Shaonian Ma Xian Zhao Zengguang Qin Zhaojun Liu Ping Lu Xiaoyi Bao Yanping Xu 《Advanced Photonics Nexus》 2024年第2期59-74,共16页
The optical rogue wave(RW),known as a short-lived extraordinarily high amplitude dynamics phenomenon with small appearing probabilities,plays an important role in revealing and understanding the fundamental physics of... The optical rogue wave(RW),known as a short-lived extraordinarily high amplitude dynamics phenomenon with small appearing probabilities,plays an important role in revealing and understanding the fundamental physics of nonlinear wave propagations in optical systems.The random fiber laser(RFL),featured with cavity-free and“modeless”structure,has opened up new avenues for fundamental physics research and potential practical applications combining nonlinear optics and laser physics.Here,the extreme event of optical RW induced by noise-driven modulation instability that interacts with the cascaded stimulated Brillouin scattering,the quasi-phase-matched four-wave mixing as well as the random mode resonance process is observed in a Brillouin random fiber laser comb(BRFLC).Temporal and statistical characteristics of the RWs concerning their emergence and evolution are experimentally explored and analyzed.Specifically,temporally localized structures with high intensities including chair-like pulses with a sharp leading edge followed by a trailing plateau appear frequently in the BRFLC output,which can evolve to chair-like RW pulses with adjustable pulse duration and amplitude under controlled conditions.This investigation provides a deep insight into the extreme event of RWs and paves the way for RW manipulation for its generation and elimination in RFLs through adapted laser configuration. 展开更多
关键词 optical rogue wave modulation instability random fiber laser cascaded stimulated Brillouin scattering four-wave mixing temporally localized structure
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基于梅森旋转算法的双随机PWM电机噪声抑制策略
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作者 高剑 刘晨旭 +1 位作者 刘锟 吕达飞 《防爆电机》 2025年第5期1-9,共9页
针对采用传统空间矢量脉宽调制(SVPWM)技术调制逆变器开关管时,较高的电压变化率会导致能量集中在载波频率及其倍频从而产生高频脉冲谐波的问题,在传统线性同余法的基础上提出了一种基于梅森旋转算法的双随机调制策略。通过分析梅森旋... 针对采用传统空间矢量脉宽调制(SVPWM)技术调制逆变器开关管时,较高的电压变化率会导致能量集中在载波频率及其倍频从而产生高频脉冲谐波的问题,在传统线性同余法的基础上提出了一种基于梅森旋转算法的双随机调制策略。通过分析梅森旋转算法产生伪随机数的原理,来弥补传统线性同余法不能最大程度地发挥随机脉宽调制技术(PWM)策略的谐波分散特性的不足。最后采用仿真对比不同调制策略下电流的傅里叶分析频谱图,验证该方法的有效性及优越性。仿真结果表示,采用梅森旋转调制策略对开关频率次谐波幅值以及开关频率次二倍频的谐波幅值抑制效果更为优异,能够大幅度抑制由PWM谐波引起的噪声,提升电机系统整体性能。 展开更多
关键词 空间矢量脉宽调制 线性同余法 双随机调制策略 梅森旋转算法 PWM谐波
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基于改进梅森旋转算法的永磁同步电机双随机SVPWM高频电磁振动抑制 被引量:2
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作者 陈浈斐 万向民 +2 位作者 陈书桐 王磊 王枫 《电工技术学报》 北大核心 2025年第8期2504-2517,共14页
在以变频器驱动的永磁同步电机控制系统中,传统的空间矢量脉宽调制(SVPWM)技术会在逆变器开关频率及其倍频处产生高频电流谐波,进而导致永磁同步电机在运行过程中产生较大的高频电磁振动。因此,提出一种随机开关频率与随机零矢量结合的... 在以变频器驱动的永磁同步电机控制系统中,传统的空间矢量脉宽调制(SVPWM)技术会在逆变器开关频率及其倍频处产生高频电流谐波,进而导致永磁同步电机在运行过程中产生较大的高频电磁振动。因此,提出一种随机开关频率与随机零矢量结合的双随机SVPWM控制方法,应用于永磁同步电机高频电流谐波频谱扩展中,该方法可分散集中在开关频率及其倍频处的高频谐波,有效地削弱高频电磁振动。同时,采用改进梅森旋转(MT)算法生成随机数,增强了随机序列的随机性和空间遍历性,保证了双随机SVPWM控制方法的扩频效果。实验结果表明,基于改进MT算法的双随机SVPWM控制方式达到了有效抑制电机高频段电磁振动的目的。 展开更多
关键词 永磁同步电机 电流谐波 电磁振动 双随机空间矢量脉宽调制(SVPWM)
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调制解调参数对谐振式光纤陀螺角随机游走影响分析
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作者 闫博 李俊 +3 位作者 吴凡 蓝士祺 曹康渊 岳亚洲 《中国惯性技术学报》 北大核心 2025年第7期722-726,共5页
双极性锯齿波调制解调技术是宽谱光源谐振式光纤陀螺的信号检测手段之一,其调制解调参数对陀螺的角随机游走系数具有重要影响。因此,基于宽谱光源谐振式光纤陀螺的仿真模型,分析了锯齿波频率和解调频率对宽谱光源谐振式光纤陀螺角随机... 双极性锯齿波调制解调技术是宽谱光源谐振式光纤陀螺的信号检测手段之一,其调制解调参数对陀螺的角随机游走系数具有重要影响。因此,基于宽谱光源谐振式光纤陀螺的仿真模型,分析了锯齿波频率和解调频率对宽谱光源谐振式光纤陀螺角随机游走系数影响机理,并推导了锯齿波频率和解调频率的优化系数。实验结果表明,参数优化后陀螺的角随机游走系数由3.53×10^(-3)(°)/√h减小至3.12×10^(-3)(°)/√h,提升了约12%。 展开更多
关键词 谐振式光纤陀螺 宽谱光源 角随机游走 调制解调
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新型叠层支架式电源模块力学可靠性设计
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作者 赵予心 王琼皎 付永辉 《空间电子技术》 2025年第5期81-88,共8页
随着小型航天器和商业卫星的微小化发展趋势,逐渐向重量轻,性能好,研制周期短,造价低的倾向偏移,电源模块也越来越小型化,轻量化,集成化。新型叠层支架式电源模块采用叠层支架式,通过钼铜支架对载板和底板进行连接,并兼顾其电源结构的... 随着小型航天器和商业卫星的微小化发展趋势,逐渐向重量轻,性能好,研制周期短,造价低的倾向偏移,电源模块也越来越小型化,轻量化,集成化。新型叠层支架式电源模块采用叠层支架式,通过钼铜支架对载板和底板进行连接,并兼顾其电源结构的支撑与电源模块的散热需求。相对于传统的电源模块设计,达成了标准化﹑通用化的设计目标,并节省了体积和重量。文章通过ANSYS软件进行动力学响应分析,研究其力学可靠性,并通过试验-仿真数据对比,响应误差在10%以内。新型叠层支架式电源在保证可靠性的同时,提高了电源的整机集成度与产品设计效率,为未来的产品设计提供了方向与思路。 展开更多
关键词 叠层支架式电源模块 有限元法 随机振动 力学仿真
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大功率低频比同步SVPWM随机脉冲控制算法研究 被引量:1
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作者 单宝钰 曲诗健 +2 位作者 石运卓 金宇明 许家琦 《微电机》 2025年第2期52-56,共5页
针对牵引系统不断向小型化、高功率密度化趋势下发展,如何解决系统散热与电磁噪声的问题成为了技术痛点。本文提出了一种基于大功率低频比同步SVPWM的随机脉冲控制策略。该策略结合了异步区和同步区随机脉冲算法,在全速度范围内有效降... 针对牵引系统不断向小型化、高功率密度化趋势下发展,如何解决系统散热与电磁噪声的问题成为了技术痛点。本文提出了一种基于大功率低频比同步SVPWM的随机脉冲控制策略。该策略结合了异步区和同步区随机脉冲算法,在全速度范围内有效降低了开关损耗并削弱了电磁噪声。通过Matlab仿真与地面联调试验验证了其合理性与可行性,为机车牵引系统优化提供了新方法。 展开更多
关键词 功率 同步调制 随机 仿真
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A corona modulation device structure and mechanism based on perovskite quantum dots random laser pumped using an electron beam 被引量:1
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作者 Yan ZHU Yining MU +2 位作者 Fanqi TANG Peng DU Hang REN 《Frontiers of Optoelectronics》 EI CSCD 2020年第3期291-302,共12页
Although laser pumping using electron beam(EB)has high transient power output and easy modulation based on perovskite quantum dot(PQD)film,its lasing emitting direction is the same as the pumped EB's direction.Thu... Although laser pumping using electron beam(EB)has high transient power output and easy modulation based on perovskite quantum dot(PQD)film,its lasing emitting direction is the same as the pumped EB's direction.Thus,realizing the conventional direct device structure through the film lasing mechanism is extremely difficult.Therefore,using the random lasing principle,herein,we proposed a corona modulation device structure based on PQDs random laser pumped using an EB.We discussed and stimulated the optimized designed method of the device in terms of parameters of the electronic optical device and the utilization ratio of output power and its modulation extinction ratio,respectively.According to the simulation results,this type of device structure can effectively satisfy the new random lasing mechanism in terms of high-speed and high-power modulation. 展开更多
关键词 CORONA modulation perovskite quantum dot(PQD) random laser electron beam(EB)
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基于能量聚焦和改进变分模态分解的人体生命体征检测算法 被引量:1
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作者 孙绪杰 黄晓红 邓振淼 《计算机应用研究》 北大核心 2025年第3期735-741,共7页
针对调频连续波(frequency modulated continuous wave,FMCW)雷达生命体征检测在存在大规模的随机人体运动场景中检测准确性过低的问题,提出了一种高精度的人体生命体征检测算法。该算法首先通过能量聚焦选取胸部最佳距离窗,消除运动伪... 针对调频连续波(frequency modulated continuous wave,FMCW)雷达生命体征检测在存在大规模的随机人体运动场景中检测准确性过低的问题,提出了一种高精度的人体生命体征检测算法。该算法首先通过能量聚焦选取胸部最佳距离窗,消除运动伪影的干扰;然后利用多项式拟合距离窗序列,消除距离窗的剧烈跳变,准确提取相位信号;最后,通过基于自相关功率谱密度与加权排列熵的改进变分模态分解(variational mode decomposition,VMD)算法去除相位信号中的大规模随机人体运动成分,进而可以精确估计出生命体征信号的呼吸速率(RR)和心率(HR)。使用77 GHz雷达模拟生活场景中存在大规模随机人体运动时的生命体征检测实验,尽管人体前后晃动的幅度达到20 cm,RR和HR的估计精度依然可以达到97.7%和96.9%,与RETF-TVF-EMD算法对比,精度分别提高了5.2和2.7百分点,与IAP-VMD算法对比,精度分别提升了14.3和7.9百分点,实验结果证明该算法能够精确估计大规模随机人体运动场景下的生命体征参数。 展开更多
关键词 调频连续波(FMCW)雷达 大规模随机人体运动 变分模态分解(VMD) 最佳距离窗选择
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安全芯片多模块随机组合验证方法的设计与实现 被引量:1
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作者 董攀 王延斌 陈汶永 《化工自动化及仪表》 2025年第1期131-137,共7页
安全芯片的功能隐患可能造成重大事故。安全芯片的内部功能模块很多,运行过程中是多个模块并行随机工作,采用顺序执行方式很难发现芯片的潜在问题。因此,提出一种多模块随机组合验证方法,在多款芯片上的验证结果表明:所提方法能够高效... 安全芯片的功能隐患可能造成重大事故。安全芯片的内部功能模块很多,运行过程中是多个模块并行随机工作,采用顺序执行方式很难发现芯片的潜在问题。因此,提出一种多模块随机组合验证方法,在多款芯片上的验证结果表明:所提方法能够高效率、高概率地发现芯片的多模块组合问题,提高了发现和解决安全芯片问题的效率。 展开更多
关键词 安全芯片 多模块 随机组合 密钥 加密 解密 可编程逻辑阵列
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基于Markov链的多电平随机脉宽调制策略研究
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作者 叶满园 肖兆军 +2 位作者 凌袁学 陶振宇 罗振远 《电机与控制学报》 北大核心 2025年第10期148-158,共11页
脉宽调制(PWM)策略是主要的电力电子调制方法,使用固定频率的三角载波调制,但是固定频率的载波会使输出电压中的谐波高度集中在载波频率的整数倍处,容易产生较大的电磁干扰。多电平脉宽调制策略通过增加电平数有效降低逆变器输出电压的... 脉宽调制(PWM)策略是主要的电力电子调制方法,使用固定频率的三角载波调制,但是固定频率的载波会使输出电压中的谐波高度集中在载波频率的整数倍处,容易产生较大的电磁干扰。多电平脉宽调制策略通过增加电平数有效降低逆变器输出电压的谐波含量,但是无法改变谐波的分布位置。针对这一问题,提出一种基于Markov链的多电平随机脉宽调制策略,使用随机脉宽调制法将固定载波频率随机化,将集中在载波频率倍数处的谐波分散到更宽的频域内,降低谐波的峰值。引入的Markov链可以有效改善随机数的随机分布概率,防止因为随机频率变化过大而增加电压脉冲。最后,以级联H桥型五电平逆变器为例,利用仿真模型和实验研究验证所提出的Markov链多电平随机脉宽调制策略的有效性和可行性。 展开更多
关键词 调制策略 随机脉宽调制 多电平逆变器 MARKOV链 谐波特性 电磁干扰
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