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Modulated waveforms for harmonic minimization of far-field signals in amplitude-modulated heating of the ionosphere
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作者 ZhiJian Lu Yong Li +6 位作者 Hui Li Jian Wu JingFeng Yao XingBao Lyu ChengXun Yuan ZhongXiang Zhou Ying Wang 《Earth and Planetary Physics》 2025年第2期387-399,共13页
This paper establishes an amplitude modulation heating model, simulating the far-field radiation of ELF/VLF signals generated by modulation heating, as well as the specific location and longitudinal extent of the radi... This paper establishes an amplitude modulation heating model, simulating the far-field radiation of ELF/VLF signals generated by modulation heating, as well as the specific location and longitudinal extent of the radiation source. We consider various modulation waveforms and find that square-wave modulation has the highest excitation efficiency for ELF/VLF signals, and that square-wave modulation with a smaller duty cycle(<50%) exhibits higher excitation efficiency for ELF/VLF signals, while the sin^(2)t waveform modulation yields the lowest proportion of harmonic energy in the generated signals. The amplitude of the second harmonic generated by the sin^(2)t waveform is less than one-tenth that of the fundamental frequency, and the energy of higher-frequency harmonics can be negligibly small compared with those of the fundamental wave. It is a challenging task to achieve a balance between enhancing the excitation efficiency of ELF/VLF signals and also suppressing harmonics generated by the modulated heating process. This is because the harmonics are correspondingly enhanced as the excitation efficiency of the signals is increased. However, we find that under conditions of varying effective radiant power and modulation frequency, as long as the modulation waveform is unchanged, the energy ratio between the fundamental frequency signal generated by modulated heating and each harmonic is relatively fixed, with changes only in signal intensity and the location of the radiation source zone. This implies that one can first select modulation waveforms that make the signal less prone to distortion, then increase the effective radiated power to enhance the signal strength, without concern for harmonic interference of the fundamental signal. 展开更多
关键词 ELF/VLF HARMONIC amplitude-modulated heating modulated waveforms
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Incommensurate modulated structure and its influence on the martensitic transformation temperature span of single phase multielement Ni-Cu-Co-Mn-Ga two-way shape memory single crystals
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作者 Qijia Yu Yang Liu +5 位作者 Chen Si Wenjia Wang Jiaxi Meng Jingmin Wang Jinghua Liu Chengbao Jiang 《Journal of Materials Science & Technology》 2025年第5期230-240,共11页
Significant two-way shape memory effect(TWSME)was achieved in single crystals of single-phase multielement Ni42-x Cu8 Cox Mn37 Ga13(8≤x≤12)alloys by performing thermomechanical training.However,anomalous dependence ... Significant two-way shape memory effect(TWSME)was achieved in single crystals of single-phase multielement Ni42-x Cu8 Cox Mn37 Ga13(8≤x≤12)alloys by performing thermomechanical training.However,anomalous dependence of the martensitic transformation temperature span on Co content was observed.Before training,quite a narrow temperature span of the martensitic transformation,nearly independent of the Co content,was observed in all single crystals.After training the temperature span was still narrow for 8≤x≤10.9 but was obviously expanded for 10.9<x≤12.High-resolution transmission electron microscopy revealed that at the atomic scale,there exists incommensurate modulated structure in the single phase single crystals,as evidenced by nonperiodic satellite spots in the selected area electronic diffraction patterns.Moreover,the modulated wave vector of the satellite spots was increased by higher Co contents.Combining first principal calculations it was considered that the incommensurate modulated structure originates from the formation of Co-Co pairs.After training arrays of ordered dislocations with the same Burgers vector were introduced for 8≤x≤10.9 but the network of dislocations was formed for 10.9<x≤12.Based on analysis of transmission electron microscopy,geometric phase,thermodynamics,and Landau theory,it was considered that the austenite/martensite phase interface was pinned by the network of dislocations,expanding the temperature span of the martensitic transformation.This work supplies new insights for understanding the microstructure and martensitic transformation of Ni-Mn-Ga-based alloys. 展开更多
关键词 Martensitic transformation Incommensurate modulated structure Temperature span DISLOCATION Two-way shape memory effect
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Correction:NH_(4)^(+)‑Modulated Cathodic Interfacial Spatial Charge Redistribution for High‑Performance Dual‑Ion Capacitors
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作者 Yumin Chen Ziyang Song +2 位作者 Yaokang Lv Lihua Gan Mingxian Liu 《Nano-Micro Letters》 2025年第9期94-94,共1页
Correction to:Nano-Micro Letters(2025)17:117 https://doi.org/10.1007/s40820-025-01660-0 Following publication of the original article[1],the authors reported that the supplementary file needed to be updated because th... Correction to:Nano-Micro Letters(2025)17:117 https://doi.org/10.1007/s40820-025-01660-0 Following publication of the original article[1],the authors reported that the supplementary file needed to be updated because they mistakenly used the incorrect version.The original article[1]has been corrected. 展开更多
关键词 nh modulated cathodic interfacial spatial charge redistribution dual ion capacitors supplementary file correction supplementary file
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High-speed electro-absorption modulated laser
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作者 Zhenyao Li Chen Lyu +5 位作者 Xuliang Zhou Mengqi Wang Haotian Qiu Yejin Zhang Hongyan Yu Jiaoqing Pan 《Journal of Semiconductors》 2025年第11期7-18,共12页
Currently,the global 5G network,cloud computing,and data center industries are experiencing rapid development.The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transce... Currently,the global 5G network,cloud computing,and data center industries are experiencing rapid development.The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transceivers for optical interconnection within data centers.The electro-absorption modulated laser(EML),which is widely used in optical fiber communications,data centers,and high-speed data transmission systems,represents a high-performance photoelectric conversion device.Compared to traditional directly modulated lasers(DMLs),EMLs demonstrate lower frequency chirp and higher modulation bandwidth,enabling support for higher data rates and longer transmission distances.This article introduces the composition,working principles,manufacturing processes,and applications of EMLs.It reviews the progress on advanced indium phosphide(InP)-based EML devices from research institutions worldwide,while summarizing and comparing data transmission rates and key technical approaches across various studies. 展开更多
关键词 electro-absorption modulation high-speed laser modulation bandwidth data transmission rate
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Strain-modulated superconductivity of monolayer Tc_(2)B_(2)
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作者 Zhengtao Liu Zihan Zhang +2 位作者 Hao Song Tian Cui Defang Duan 《Chinese Physics B》 2025年第4期221-227,共7页
Two-dimensional(2D)superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices.Herein,we employ first-principles calculation... Two-dimensional(2D)superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices.Herein,we employ first-principles calculations to predicted a new 2D conventional superconductor,Tc_(2)B_(2),demonstrating its stable structural configuration.Remarkably,under biaxial strain,the superconducting transition temperature(T_(c))of Tc_(2)B_(2)demonstrates a significant enhancement,achieving 19.5 K under 3%compressive strain and 9.2 K under 11%tensile strain.Our study reveals that strain-induced modifications in Fermi surface topology significantly enhance the Fermi surface nesting effect,which amplifies electron–phonon coupling interactions and consequently elevates Tc.Additionally,the presence of the Lifshitz transition results in a more pronounced rise in Tc under compressive strain compared to tensile strain.These insights offer important theoretical guidance for designing 2D superconductors with high-Tc through strain modulation. 展开更多
关键词 TWO-DIMENSIONAL SUPERCONDUCTIVITY strain modulation first-principles calculation
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Neurotensin Modulates Emotional Valence Assignment in the Basolateral Amygdala Through Neuromodulator Gain
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作者 Maimaitishalijiang Abudureheman Yu-Hao Xiao +1 位作者 Li-Zang Zeng Hong-Yan Geng 《Neuroscience Bulletin》 2025年第1期177-180,共4页
Based on previous experience,learning to avoid or seek certain specific stimuli again in the future is crucial for survival.Our brains are wired to assign a particular valence-either positive or negativeas a result of... Based on previous experience,learning to avoid or seek certain specific stimuli again in the future is crucial for survival.Our brains are wired to assign a particular valence-either positive or negativeas a result of sensory stimuli,and it is this valence that serves as the foundational motivation for our subsequent actions.Simply put,all motivational actions fall into two categories:pleasure-seeking behavior guided by positive emotional valence,and pain-avoiding behavior driven by negative emotional valence[1].The ability to shift from one emotional valence to another is an important characteristic of affective states,while the instability of emotional states underlies many psychiatric disorders,highlighting the clinical importance of managing and understanding these fluctuations.This ability to adapt emotional responses can be attained by modulating the gain across distinct neural pathways,thus enabling the nuanced and smooth assignment of valence through the strengthening or weakening of circuit activity[1,2]. 展开更多
关键词 EMOTIONAL MOTIVATION MODULATOR
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Dromion structure in(2+1)-dimensional modulated positron-acoustic waves in a non-Maxwellian magnetoplasma
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作者 Aljawhara H Almuqrin Alim +5 位作者 B B Mouhammadoul C G L Tiofack A Mohamadou Sherif M E Ismaeel Weaam Alhejaili S A El-Tantawy 《Communications in Theoretical Physics》 2025年第5期171-183,共13页
This study investigates the dromion structure within the context of(2+1)-dimensional modulated positron-acoustic waves in a magnetoplasma consisting of inertial cold positrons and inertialess nonthermal hot electrons ... This study investigates the dromion structure within the context of(2+1)-dimensional modulated positron-acoustic waves in a magnetoplasma consisting of inertial cold positrons and inertialess nonthermal hot electrons and positrons as well as stationary positive ions.The reductive perturbation approach reduces the fluid governing equations to the plasma model to a Davey–Stewartson system.This study provides a detailed analysis of the influence of many related plasma parameters,including the density ratio of hot and cold positrons,the external magnetic field strength,the nonthermal parameter and the density ratio of electrons and cold positrons,on the growing rate of instability.Using the Hirota Bilinear method,it is found that the system supports some exact solutions,such as one-and two-dromion solutions.The change of plasma parameters significantly enhances the characteristics of dromion solutions.The elastic and inelastic collisions between two dromions are discussed at different times.The relevance of this study can help us to understand the various types of collision between energetic particles in confined plasma during the production of energy by thermonuclear fusion. 展开更多
关键词 Davey-Stewartson equations positron-acoustic waves modulational instability magnetoplasmas dromion soliton
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Femtosecond laser modulated into Bessel beam by spatial light modulator for Fresnel zone plate processing
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作者 DUAN Lian ZHOU Fang +3 位作者 KONG De-jian ZHANG Fan SUN Xiao-yan DUAN Ji-an 《Journal of Central South University》 2025年第2期469-482,共14页
Femtosecond laser processing is an important machining method for micro-optical components such as Fresnel zone plate(FZP).However,the low processing efficiency of the femtosecond laser restricts its application.Here,... Femtosecond laser processing is an important machining method for micro-optical components such as Fresnel zone plate(FZP).However,the low processing efficiency of the femtosecond laser restricts its application.Here,a femtosecond laser Bessel beam is proposed to process micro-FZP,which is modulated from a Gaussian beam to a Bessel annular beam.The processing time for FZP with an outer diameter of 60μm is reduced from 30 min to 1.5 min on an important semiconductor material gallium arsenide(GaAs),which significantly improves the processing efficiency.In the modulation process,a central ablation hole that has an adverse effect on the diffraction performance is produced,and the adverse effect is eliminated by superimposing the blazed grating hologram.Meanwhile,the FZP machined by spatial light modulator(SLM)has good morphology and higher diffraction efficiency,which provides a strong guarantee for the application of micro-FZP in computed tomography and solar photovoltaic cells. 展开更多
关键词 femtosend laser Fresnel zone plate spatial light modulator Bessel beam GAAS
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Using Targeted Phonon Excitation to Modulate Thermal Conductivity of Boron Nitride
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作者 Dongkai Pan Tianhao Li +3 位作者 Xiao Wan Zhicheng Zong Yangjun Qin Nuo Yang 《Chinese Physics Letters》 2025年第7期449-453,共5页
Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials.In this article,both the iterative Boltzmann tran... Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials.In this article,both the iterative Boltzmann transport equation solution and the two-temperature model were employed to investigate the efficacy of targeted phonon excitation applied to hexagonal boron nitride(hBN).The results indicate significant modifications to hBN's thermal conductivity,achieving increases of up to 30.1%as well as decreases of up to 59.8%.These findings validate the reliability of the strategy,expand its scope of applicability,and establish it as a powerful tool for tailoring thermal properties across a wider range of fields. 展开更多
关键词 thermal conductivityachieving thermal management capabilities boron nitride targeted phonon excitation iterative boltzmann transport equation solution hexagonal boron nitride hbn thermal conductivity modulating strategies thermal conductivity
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One-step direct ammonia synthesis by pulse-modulated microwave plasma at atmospheric pressure
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作者 Wei WANG Yao LI +5 位作者 Zhaoquan CHEN Sisi LI Yi FENG Zhi ZHENG Dezheng YANG Yue LIU 《Plasma Science and Technology》 2025年第4期112-121,共10页
In this study,we explored a one-step direct synthesis of NH3 under mild experimental conditions utilizing pulse-modulated microwave plasma technology at atmospheric pressure.At a substantial gas flow rate,a microwave ... In this study,we explored a one-step direct synthesis of NH3 under mild experimental conditions utilizing pulse-modulated microwave plasma technology at atmospheric pressure.At a substantial gas flow rate,a microwave plasma jet was formed and the microwave-assisted ammonia synthesis can be realized.Impacts of various parameters including the gas flow rate,gas component,microwave absorbed power,pulse modulation frequency,and pulse duty cycle on ammonia synthesis were systematically investigated.To indicate the reaction path of ammonia synthesis,the distributions of both the gas temperature and active species were also studied using optical emission spectra technology.It is found that a considerable amount of ammonia was directly synthesized without involvement of any catalysts,the highest ammonia production rate and energy efficiency(EE),up to 2.93μmol·min^(-1) and 6.64×10^(-2)g·(k W·h)^(-1),respectively,were achieved under low microwave power of 84.42 W.The duty cycle has obvious influences on the synthesis efficiency,compared to a duty cycle of 80%,the ammonia synthesis rate,EE and nitrogen conversion decreased by about 22%at a duty cycle of 100%.This finding underscores the significance of incorporating pulse modulation in the microwave discharge process for ammonia synthesis.Furthermore,it was found that vibrational excitation of microwave plasma has a significant driving effect on ammonia synthesis. 展开更多
关键词 microwave plasma ammonia synthesis pulse modulation plasma jet microwave resonant cavity(Some figures may appear in colour only in the online journal)
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Modulated-ISRJ rejection using online dictionary learning for synthetic aperture radar imagery 被引量:1
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作者 WEI Shaopeng ZHANG Lei +1 位作者 LU Jingyue LIU Hongwei 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期316-329,共14页
In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes consid... In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes considerable coherence with the SAR transmission waveform together with periodical modulation patterns.This paper develops an MISRJ suppression algorithm for SAR imagery with online dictionary learning.In the algorithm,the jamming modulation temporal properties are exploited with extracting and sorting MISRJ slices using fast-time autocorrelation.Online dictionary learning is followed to separate real signals from jamming slices.Under the learned representation,time-varying MISRJs are suppressed effectively.Both simulated and real-measured SAR data are also used to confirm advantages in suppressing time-varying MISRJs over traditional methods. 展开更多
关键词 synthetic aperture radar(SAR) modulated interrupt sampling jamming(MISRJ) online dictionary learning
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Preclinical Verification of Modulated Electro-Hyperthermia —Part I. In Vitro Research
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作者 Andras Szasz 《International Journal of Clinical Medicine》 CAS 2024年第7期257-298,共42页
Modulated electro-hyperthermia (mEHT) targets tissue’s natural electric and thermal heterogeneities to heat the cancer cells selectively. The applied 13.56 MHz radiofrequency (RF) is a carrier of the low-frequency mo... Modulated electro-hyperthermia (mEHT) targets tissue’s natural electric and thermal heterogeneities to heat the cancer cells selectively. The applied 13.56 MHz radiofrequency (RF) is a carrier of the low-frequency modulation. The high-frequency part was chosen to select the malignant lesion using the specialties of the tumor: the higher conductivity and dielectric constant of the tumor than its host. The electric field selects the tumor, and the low-frequency amplitude modulation polarizes and excites the transmembrane proteins of the malignant cells. The dominant absorption of the energy by the microscopic clusters of the membrane rafts acts like nanoparticle heating. Exciting the membrane produces various apoptotic signals. The processes were modeled using silico and phantom experiments, which proved the concept. The preclinical verification was made in vitro and in vivo, and in the end, clinical proofs validated the method. Our objective is to follow all the development steps from the laboratory to the clinics in a trilogy of articles. This present is the first part, which deals with in silico, phantom, and in vitro research. 展开更多
关键词 modulated Electro-Hyperthermia mEHT In Silico Calculations Phantom Measurement In Vitro Experiments Thermal Effects Nonthermal Processes Apoptosis
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Age of Information for Short-Packet Covert Communication with Time Modulated Retrodirective Array 被引量:1
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作者 Ma Yue Ma Ruiqian +4 位作者 Lin Zhi Yang Weiwei Cai Yueming Miao Chen Wu Wen 《China Communications》 SCIE CSCD 2024年第4期23-37,共15页
In this paper,the covert age of information(CAoI),which characterizes the timeliness and covertness performance of communication,is first investigated in the short-packet covert communication with time modulated retro... In this paper,the covert age of information(CAoI),which characterizes the timeliness and covertness performance of communication,is first investigated in the short-packet covert communication with time modulated retrodirective array(TMRDA).Specifically,the TMRDA is designed to maximize the antenna gain in the target direction while the side lobe is sufficiently suppressed.On this basis,the covertness constraint and CAoI are derived in closed form.To facilitate the covert transmission design,the transmit power and block-length are jointly optimized to minimize the CAoI,which demonstrates the trade-off between covertness and timelessness.Our results illustrate that there exists an optimal block-length that yields the minimum CAoI,and the presented optimization results can achieve enhanced performance compared with the fixed block-length case.Additionally,we observe that smaller beam pointing error at Bob leads to improvements in CAoI. 展开更多
关键词 age of information covert communication retrodirective array time modulation
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Voltage-modulated polymer nanopore field-effect transistor for multi-sized nanoparticle detection
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作者 Feng Zhou Lin Li Qiannan Xue 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第3期79-89,共11页
Solid-state nanopores offer a range of distinct advantages over biological nanopores,such as structural diversity and greater stability and durability;this makes them highly promising for high-resolution nanoparticle ... Solid-state nanopores offer a range of distinct advantages over biological nanopores,such as structural diversity and greater stability and durability;this makes them highly promising for high-resolution nanoparticle sensing.Biological nanopores can exhibit gating characteristics with stress-responsive switches and can demonstrate specificity toward particular molecules.Drawing inspiration from biological nanopores,this paper introduces a novel polymer nanopore with field-effect characteristics,leveraging a conductive polymer in its construction to showcase intriguing gating behavior.Notably,in this device,the polymer layer serves as the gate,enabling precise control over the source–drain current response inside and outside the pore by simply adjusting the gate voltage.This unique feature allows fine-tuning of the nanopore’s sensitivity to nanoparticles of varying sizes and facilitates its operation in multiple modes.Experimental results reveal that the developed polymer nanopore field-effect transistor demonstrates remarkable selectivity in detecting nanoparticles of various sizes under different applied voltages.The proposed single device demonstrates the exceptional ability to detect multiple types of nanoparticle,showcasing its immense potential for a wide range of applications in biological-particle analysis and medical diagnostics. 展开更多
关键词 Nanopipette Polymer nanopore Voltage modulation Nanoparticle detection
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Topological Structure-Modulated Collagen Carbon as Two-in-One Energy Storage Configuration toward Ultrahigh Power and Energy Density
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作者 Li Yuan Wenlong Cai +4 位作者 Yunhong Wei Yiran Pu Can Liu Yun Zhang Hao Wu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期18-29,共12页
Efficient energy storage devices with suitable electrode materials,that integrate high power and high energy,are the crucial requisites of the renewable power source,which have unwrapped new possibilities in the susta... Efficient energy storage devices with suitable electrode materials,that integrate high power and high energy,are the crucial requisites of the renewable power source,which have unwrapped new possibilities in the sustainable development of energy and the environment.Herein,a facile collagen microstructure modulation strategy is proposed to construct a nitrogen/oxygen dual-doped hierarchically porous carbon fiber with ultrahigh specific surface area(2788 m^(2)g^(-1))and large pore volume(4.56 cm^(3)g^(-1))via local microfibrous breakage/disassembly of natural structured proteins.Combining operando spectroscopy and density functional theory unveil that the dual-heteroatom doping could effectively regulate the electronic structure of carbon atom framework with enhanced electric conductivity and electronegativity as well as decreased diffusion resistance in favor of rapid pseudocapacitive-dominated Li^(+)-storage(353 mAh g^(-1)at 10 A g^(-1)).Theoretical calculations reveal that the tailored micro-/mesoporous structures favor the rapid charge transfer and ion storage,synergistically realizing high capacity and superior rate performance for NPCF-H cathode(75.0 mAh g^(-1)at 30 A g^(-1)).The assembled device with NPCF-H as both anode and cathode achieves extremely high energy density(200 Wh kg^(-1))with maximum power density(42600 W kg^(-1))and ultralong lifespan(80%capacity retention over 10000 cycles). 展开更多
关键词 collagen carbon energy storage device theoretical calculations topological structure modulation ultrahigh power and energy density
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Optimal design of modular dual-field modulated permanent magnet linear motors with thrust characteristics
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作者 MIAO Zhongcui ZHANG Lei +1 位作者 LI Yan ZHANG Hui 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第4期547-557,共11页
To reduce thrust ripple and cost and improve the average thrust of permanent magnet linear motors,a modular dual-field modulation permanent magnet linear motor was studied,and the parameters were optimized.First,sensi... To reduce thrust ripple and cost and improve the average thrust of permanent magnet linear motors,a modular dual-field modulation permanent magnet linear motor was studied,and the parameters were optimized.First,sensitive parameters were selected using the Taguchi method,and then the optimal variables were sampled using the optimal Latin hypercube experimental design method and an ensemble of surrogates model of optimization objectives,and its accuracy was verified.Next,a multi-objective particle swarm optimization algorithm was used to optimize the purpose of“maximum average thrust and minimum thrust ripple”,and the Pareto front of average thrust and thrust ripple was obtained.Finite element analysis showed that the optimized modular dual flux-modulation permanent magnet linear motor(MDFMPMLM)had a 29.5%reduction in thrust ripple and a 5%increase in average thrust compared to the original motor.This study provided an effective method for improving the performance of permanent magnet linear motors. 展开更多
关键词 field modulation thrust characteristics finite element analysis ensemble of surrogates model permanent magnet linear motor multi-objective optimization
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Simultaneous modulated accelerated radiation therapy for esophageal cancer:A feasibility study 被引量:12
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作者 Wu-Zhe Zhang Jian-Zhou Chen +6 位作者 De-Rui Li Zhi-Jian Chen Hong Guo Ting-Ting Zhuang Dong-Sheng Li Ming-Zhen Zhou Chuang-Zhen Chen 《World Journal of Gastroenterology》 SCIE CAS 2014年第38期13973-13980,共8页
AIM: To establish the feasibility of simultaneous modulated accelerated radiation therapy (SMART) in esophageal cancer (EC).
关键词 Simultaneous modulated accelerated radiation therapy Three-dimensional conformal radiotherapy Intensity-modulated radiation therapy Esophageal cancer FEASIBILITY
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Dosimetry Comparison between Volumetric Modulated Arc Therapy with RapidArc and Fixed Field Dynamic IMRT for Local-Regionally Advanced Nasopharyngeal Carcinoma 被引量:8
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作者 Bao-min Zheng Xiao-xia Dong +3 位作者 Hao Wu You-jia Duan Shu-kui Han Yan Sun 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2011年第4期259-264,共6页
Objective: A dosimetric study was performed to evaluate the performance of volumetric modulated arc radiotherapy with RapidArc on locally advanced nasopharyngeal carcinoma (NPC). Methods: The CT scan data sets of 20 p... Objective: A dosimetric study was performed to evaluate the performance of volumetric modulated arc radiotherapy with RapidArc on locally advanced nasopharyngeal carcinoma (NPC). Methods: The CT scan data sets of 20 patients of locally advanced NPC were selected randomly. The plans were managed using volumetric modulated arc with RapidArc and fixed nine-field coplanar dynamic intensity-modulated radiotherapy (IMRT) for these patients. The dosimetry of the planning target volumes (PTV), the organs at risk (OARs) and the healthy tissue were evaluated. The dose prescription was set to 70 Gy to the primary tumor and 60 Gy to the clinical target volumes (CTV) in 33 fractions. Each fraction applied daily, five fractions per week. The monitor unit (MU) values and the delivery time were scored to evaluate the expected treatment efficiency. Results: Both techniques had reached clinical treatment’s requirement. The mean dose (Dmean), maximum dose (Dmax) and minimum dose (Dmin) in RapidArc and fixed field IMRT for PTV were 68.4±0.6 Gy, 74.8±0.9 Gy and 56.8±1.1 Gy; and 67.6±0.6 Gy, 73.8±0.4 Gy and 57.5±0.6 Gy (P<0.05), respectively. Homogeneity index was 78.85±1.29 in RapidArc and 80.34±0.54 (P<0.05) in IMRT. The conformity index (CI: 95%) was 0.78±0.01 for both techniques (P>0.05). Compared to IMRT, RapidArc allowed a reduction of Dmean to the brain stem, mandible and optic nerves of 14.1% (P<0.05), 5.6% (P<0.05) and 12.2% (P<0.05), respectively. For the healthy tissue and the whole absorbed dose, Dmean of RapidArc was reduced by 3.6% (P<0.05), and 3.7% (P<0.05), respectively. The Dmean to the parotids, the spinal cord and the lens had no statistical difference among them. The mean MU values of RapidArc and IMRT were 550 and 1,379. The mean treatment time of RapidArc and IMRT was 165 s and 447 s. Compared to IMRT, the delivery time and the MU values of RapidArc were reduced by 63% and 60%, respectively. Conclusion: For locally advanced NPC, both RapidArc and IMRT reached the clinic requirement. The target volume coverage was similar for the different techniques. The RapidArc technique showed some improvements in OARs and other tissue sparing while using reduced MUs and delivery time. 展开更多
关键词 Volumetric modulated arc therapy Intensity-modulated radiotherapy DOSIMETRY Target volume Nasopharyngeal carcinoma
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Helical tomotherapy and volumetric modulated arc therapy:New therapeutic arms in the breast cancer radiotherapy 被引量:7
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作者 Olivier Lauche Youlia M Kirova +8 位作者 Pascal Fenoglietto Emilie Costa Claire Lemanski Celine Bourgier Olivier Riou David Tiberi Francois Campana Alain Fourquet David Azria 《World Journal of Radiology》 CAS 2016年第8期735-742,共8页
AIM To analyse clinical and dosimetric results of helical tomotherapy(HT)and volumetric modulated arc therapy(VMAT)in complex adjuvant breast and nodes irradiation.METHODS Seventy-three patients were included(31 HT an... AIM To analyse clinical and dosimetric results of helical tomotherapy(HT)and volumetric modulated arc therapy(VMAT)in complex adjuvant breast and nodes irradiation.METHODS Seventy-three patients were included(31 HT and 42 VMAT).Dose were 63.8 Gy(HT)and 63.2 Gy(VMAT)in the tumour bed,52.2 Gy in the breast,50.4 Gy in supraclavicular nodes(SCN)and internal mammary chain(IMC)with HT and 52.2 Gy and 49.3 Gy in IMC and SCN with VMAT in 29 fractions.Margins to particle tracking velocimetry were greater in the VMAT cohort(7 mm vs 5 mm).RESULTS For the HT cohort,the coverage of clinical target volumes was as follows:Tumour bed:99.4%±2.4%;breast:98.4%±4.3%;SCN:99.5%±1.2%;IMC:96.5%±13.9%.For the VMAT cohort,the coverage was as follows:Tumour bed:99.7%±0.5%,breast:99.3%±0.7%;SCN:99.6%±1.4%;IMC:99.3%±3%.For ipsilateral lung,Dmean and V20 were 13.6±1.2 Gy,21.1%±5%(HT)and 13.6±1.4 Gy,20.1%±3.2%(VMAT).Dmean and V30 of the heart were 7.4±1.4 Gy,1%±1%(HT)and 10.3±4.2 Gy,2.5%±3.9%(VMAT).For controlateral breast Dmean was 3.6±0.2 Gy(HT)and 4.6±0.9 Gy(VMAT).Acute skin toxicity grade 3 was 5%in the two cohorts.CONCLUSION HT and VMAT in complex adjuvant breast irradiation allow a good coverage of target volumes with an acceptable acute tolerance.A longer follow-up is needed to assess the impact of low doses to healthy tissues. 展开更多
关键词 Three-dimensional conformal radiotherapy Intensity modulated radiation therapy TOXICITY Helical tomotherapy Volumetric modulated arc therapy Breast cancer radiotherapy
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On approximating multifractal traffic burstiness with Markov modulated Poisson processes 被引量:1
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作者 纪其进 《Journal of Southeast University(English Edition)》 EI CAS 2004年第4期436-441,共6页
We investigate the approximating capability of Markov modulated Poisson processes (MMPP) for modeling multifractal Internet traffic. The choice of MMPP is motivated by its ability to capture the variability and correl... We investigate the approximating capability of Markov modulated Poisson processes (MMPP) for modeling multifractal Internet traffic. The choice of MMPP is motivated by its ability to capture the variability and correlation in moderate time scales while being analytically tractable. Important statistics of traffic burstiness are described and a customized moment-based fitting procedure of MMPP to traffic traces is presented. Our methodology of doing this is to examine whether the MMPP can be used to predict the performance of a queue to which MMPP sample paths and measured traffic traces are fed for comparison respectively, in addition to the goodness-of-fit test of MMPP. Numerical results and simulations show that the fitted MMPP can approximate multifractal traffic quite well, i.e. accurately predict the queueing performance. 展开更多
关键词 multifractal traffic Markov modulated Poisson processes queueing delay packet loss rate
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