- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Coulomb interaction-induced jitter amplification in RF-compressed high-brightness electron source ultrafast electron diffraction
摘要： We have theoretically and experimentally demonstrated an RF compression-based jitter-amplification effect in high-brightness electron source ultrafast electron diffraction (UED), which degrades the temporal resolution significantly. A detailed analysis and simulations reveal the crucial role of the longitudinal and transverse Coulomb interaction for this jitter-amplification effect, which accord very well with experimental results. An optimized compact UED structure for full compression has been proposed, which can suppress the jitter by half and improve the temporal resolution to sub-100 fs. This Coulomb interaction-induced jitter amplification exists in nearly the whole ultrafast physics field where laser-electron synchronization is required. Moreover, it cannot be suppressed completely. The quantified explanation for the mechanism and optimization provides important guidance for photocathode accelerators and other compression-based ultrashort electron pulse generation and precise control.
关键词： system optimization,jitter amplification,RF compression,high-brightness electron source,ultrafast electron diffraction,Coulomb interaction
更新于2025-09-23 15:21:21
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[IEEE 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus) - St. Petersburg and Moscow, Russia (2020.1.27-2020.1.30)] 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus) - The Study of Three-dimensional Tissue-engineering Structures Obtained Using Laser Printing for Muscle Regeneration
摘要： Existing optimization methods to heterogeneous redundancy allocation problem often suffer from the local-trap problem in optimization, due to the rugged energy landscapes. In this paper, a new optimization paradigm based on the Markov chain Monte Carlo sampling is proposed for solving the heterogeneous redundancy allocation for multi-state systems. We address this in an optimization-by-sampling framework, and propose to sample the intricate distribution over the combinatorial space by a doubly adaptive sampling approach, where the target adaptation favors free random walk on the rugged energy landscape to substantially alleviate the local-trap problem by updating the target distribution on-the-fly, while the proposal adaptation helps improve the sampling efficiency by learning the proposal distribution based on chain history in optimization. Experimental results performed on a range of benchmark instances demonstrated the superiority of the proposed optimization approach compared with the state-of-the-art alternatives in terms of the solution quality or computational efficiency.
关键词： multi-state system,Optimization-by-sampling,Markov chain Monte Carlo,redundancy allocation problem
更新于2025-09-19 17:13:59
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Research of PAM-4 Modulated WDM-PON Architecture for 5G Millimeter-wave Hybrid Photonics-wireless Interface
摘要： Existing optimization methods to heterogeneous redundancy allocation problem often suffer from the local-trap problem in optimization, due to the rugged energy landscapes. In this paper, a new optimization paradigm based on the Markov chain Monte Carlo sampling is proposed for solving the heterogeneous redundancy allocation for multi-state systems. We address this in an optimization-by-sampling framework, and propose to sample the intricate distribution over the combinatorial space by a doubly adaptive sampling approach, where the target adaptation favors free random walk on the rugged energy landscape to substantially alleviate the local-trap problem by updating the target distribution on-the-fly, while the proposal adaptation helps improve the sampling efficiency by learning the proposal distribution based on chain history in optimization. Experimental results performed on a range of benchmark instances demonstrated the superiority of the proposed optimization approach compared with the state-of-the-art alternatives in terms of the solution quality or computational efficiency.
关键词： Markov chain Monte Carlo,multi-state system,Optimization-by-sampling,redundancy allocation problem
更新于2025-09-19 17:13:59
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Study on the general system integration optimization method of the solar aided coal-fired power generation system
摘要： Solar aided coal-fired power generation (SAPG) has been attracted more and more attentions in recent years. However, its integration and optimization is a rather challenging work. Most of the studies are based on the researches of one or several certain schemes, and no general system integration optimization method (GIOM) considering all possibilities has been proposed. In this paper, a general system integration optimization model is developed, which is configured with 8 virtual molten salt heat exchangers (FHms) and used to simulate any scheme of different integration locations and heat distributions. A SAPG system based on Solar Two plant and a 600 MWe supercritical coal-fired plant is studied. The results show that at the relatively higher heliostat field power (HFP) work conditions, the heat energy should be injected into the highest pressure feedwater heater (FHs) as a priority. While at the relatively lower HFP and higher turbine power work conditions, the heat should be distributed to the two highest pressure FHs in a certain proportion instead of fully distributed to the highest pressure FHs. The performances of both the receiver and the power block are improved. The solar-electric conversion efficiency of SAPG system is obviously higher than that of Solar Two.
关键词： Optimal integration scheme,Solar aided power generation,Concentrating solar power,Integration system optimization,Coal-fired power plant
更新于2025-09-04 15:30:14