检索结果-南通市图书馆

Ultrahigh spatiotemporal resolution beam signal reconstruction with bunch phase compensation

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 99-108页

作者： You-Ming Deng Yong-Bin Leng Xing-Yi Xu Jian Chen Yi-Mei Zhou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China university of the chinese academy of sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Chinese Academy of SciencesShanghai 201204China university of Science and Technology of China Hefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle *** is important to obtain time-domain waveforms of these signals with high temporal resolution for research,such as the study of beam–cavity interactions and bunch-by-bunch parameter ***,a signal reconstruction algorithm with ultrahigh spatiotemporal resolution and bunch phase compensation based on equivalent sampling is proposed in this *** with traditional equivalent sampling,the use of phase compensation and setting the bunch signal zero-crossing point as the time reference can construct a more accurate reconstructed *** basic principles of the method,simulation,and experimental comparison are also *** on the beam test platform of the Shanghai Synchrotron Radiation Facility(SSRF)and the method of experimental verification,the factors that affect the reconstructed signal quality are analyzed and discussed,including the depth of the sampled data,quantization noise of analog-to-digital converter,beam transverse oscillation,and longitudinal *** results of the beam experiments show that under the user operation conditions of the SSRF,a beam excitation signal with an amplitude uncertainty of 2%can be reconstructed.

关键词： Turn-by-turn bunch phase compensation technique Equivalent sampling Signal reconstruction algorithm Ultrahigh spatiotemporal resolution SSRF

Multiple thermal events recorded in the Acasta Gneiss Complex:Evidence from in-situ dating of zircon, titanite, and apatite

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2024年第3期67卷 673-686页

作者： Qingfeng MEI Jinhui YANG Jinfeng SUN Qiuli LI Shitou WU Xiaoxiao LING Peng PENG Hao WANG State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Computational Geodynamics University of Chinese Academy of SciencesBeijing 100049China

In-situ dating of the zircons, titanites, and apatites in the rock fragments of approximately 1 cm2in size from the Acasta Gneiss Complex was performed using secondary ion mass spectrometry or laser ablation inductively coupled plasma mass spectrometry to provide constraints on the thermal history of the Acasta Gneiss Complex. The zircons in these rock fragments typically exhibit multiple age populations, reflecting the presence of inherited zircons or the post-crystallization process of zircon overgrowth. Combined with previous studies, our zircon dating results reveal multiple magmatic events that occurred in the Acasta Gneiss Complex, specifically at >3.96, ~3.72, and ~3.57 Ga, respectively. A titanite Pb-Pb isochron age of2911±22 Ma(95% confidence level, MSWD=1.5) for sample AY199 is identified, consistent with the timing of the latest Archean magmatism in the Acasta Gneiss Complex. The titanite U-Pb ages for samples AC478 and AY066 are 1932±270 Ma(95% confidence level, MSWD=2.3) and 1813±45 Ma(95% confidence level, MSWD=2.3), respectively. The apatites in sample P090803-C exhibit a Pb-Pb isochron age of 1833±26 Ma(95% confidence level, MSWD=1.4). The apatite U-Pb ages for samples AC478, AY199, and AY066 are 1850±20 Ma(95% confidence level, MSWD=1.3), 1827±100 Ma(95% confidence level, MSWD=6.3), and 1807±58 Ma(95% confidence level, MSWD=3.9), respectively. Titanites in samples AC478 and AY066, as well as the apatites in all four investigated samples, show a uniform age(Pb-Pb or U-Pb age) of ~1.9–1.8 Ga,indicating U-Pb system reset in these minerals due to the Wopmay orogeny and documenting that the peak temperature condition associated with the Wopmay orogeny exceeded the apatite U-Pb closure temperature and approached or exceeded that of titanite.

关键词： Zircon Titanite Apatite Acasta Gneiss Complex Wopmay Orogen

Enhancing Multi-agent Coordination via Dual-channel Consensus

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第2期21卷 349-368页

作者： Qingyang Zhang Kaishen Wang Jingqing Ruan Yiming Yang Dengpeng Xing Bo Xu Institute of Automation Chinese Academy of SciencesBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

Successful coordination in multi-agent systems requires agents to achieve *** works propose methods through information sharing,such as explicit information sharing via communication protocols or exchanging information implicitly via behavior ***,these methods may fail in the absence of communication channels or due to biased *** this work,we propose to develop dual-channel consensus(DuCC)via contrastive representation learning for fully cooperative multi-agent systems,which does not need explicit communication and avoids biased *** comprises two types of consensus:temporally extended consensus within each agent(inner-agent consensus)and mutual consensus across agents(inter-agent consensus).To achieve DuCC,we design two objectives to learn representations of slow environmental features for inner-agent consensus and to realize cognitive consistency as inter-agent *** DuCC is highly general and can be flexibly combined with various MARL *** extensive experiments on StarCraft multi-agent challenge and Google research football demonstrate that our method efficiently reaches consensus and performs superiorly to state-of-the-art MARL algorithms.

关键词： Multi-agent reinforcement learning contrastive representation learning consensus multi-agent cooperation cognitive consistency

Design study of charge-stripping scheme of heavy ion beams for HIAF-BRing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 30-41页

作者： Jun-Jie Zhang Zhi-You Xu Jin-Quan Zhang Wen-Wen Ge Liang-Ting Sun Huan-Yu Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Charge strippers play an essential role in heavy-ion accelerators by stripping the projectile ions to higher charge states to enhance the acceleration efficiency downstream of the *** the high-energy mode of the booster ring(BRing)of the high-intensity heavy-ion accelerator facility,the pre-accelerated ions from the iLinac will be stripped by a carbon foil to higher charge states and then injected into the *** key parameters of the stripper and stripped ions were calculated,and the influence of stripping on the beam quality was *** get high stripping efficiencies,the foil thicknesses and resultant charge state distributions for the typical ions were determined by the code *** equilibrium thickness was obtained for the U beam,while the stripper thicknesses for the Xe and Kr beams were determined based on a compromise between the stripped charge states and the stripping *** energy loss,energy straggling,and emittance growth due to stripping have a non-negligible impact on the transport of the stripped beams and the injection of the ***,these parameters were simulated by *** addition,the foil’s temperature evolution,which greatly affects the foil lifetime,was simulated by *** maximum temperature of the foil bombarded by the U and Xe beams with the nominal parameters will exceed the safe value in terms of the impact of evaporation on the foil’s *** the foil temperature constraint,the highest tolerable beam intensity and the injected ion number into the ring were derived for different beam *** results of this paper will present important reference data for the optimization design and commissioning of the beamline and injection to the BRing for the stripped ions.

关键词： High-intensity heavy-ion accelerator facility Charge stripper Energy spread Thermal analysis Emittance growth Injection turns

Silicon-based optoelectronic heterogeneous integration for optical interconnection

在线全文

学校读者我要写书评

暂无评论

chinese Physics B 2024年第2期33卷 1-9页

作者：李乐良李贵柯张钊刘剑吴南健王开友祁楠刘力源 Institute of Semiconductors Chinese Academy of SciencesBeijing 100083China Center of Material Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The performance of optical interconnection has improved dramatically in recent ***-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated *** paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical *** research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.

关键词： silicon-based heterogeneous integration heterogeneous integrated materials heterogeneous integrated packaging optical interconnection

Functional divergences of natural variations of TaNAM-A1 in controlling leaf senescence during wheat grain filling

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第6期66卷 1242-1260页

作者： Longxi Zhou Guowei Chang Chuncai Shen Wan Teng Xue He Xueqiang Zhao Yanfu Jing Zhixiong Huang Yiping Tong Key Laboratory of Seed Innovation Institute of Genetics and Developmental SciencesChinese Academy of SciencesBeijing 100101China university of chinese academy of sciences Beijing 100049China The Innovative academy of Seed Design Chinese Academy of SciencesBeijing 100101China

Leaf senescence is an essential physiological process related to grain yield potential and nutritional *** leaf duration(GLD)after anthesis directly reflects the leaf senescence process and exhibits large genotypic differences in common wheat;however,the underlying gene regulatory mechanism is still ***,we identified TaNAM-A1 as the causal gene of the major loci q GLD-6A for GLD during grain filling by map-based *** assays and TILLING mutant analyses demonstrated that TaNAM-A1 played a critical role in regulating leaf senescence,and also affected spike length and grain ***,the functional divergences among the three haplotypes of TaNAM-A1 were systematically *** varieties with TaNAM-A1d(containing two mutations in the coding DNA sequence of TaNAM-A1)exhibited a longer GLD and superior yield-related traits compared to those with the wild type *** three haplotypes were functional in activating the expression of genes involved in macromolecule degradation and mineral nutrient remobilization,with TaNAM-A1a showing the strongest activity and TaNAM-A1d the ***-A1 also modulated the expression of the senescencerelated transcription factors TaNAC-S-7A and ***016-3A enhanced the transcriptional activation ability of TaNAM-A1a by protein–protein interaction,thereby promoting the senescence *** study offers new insights into the fine-tuning of the leaf functional period and grain yield formation for wheat breeding under various geographical climatic conditions.

关键词： allelic variation leaf senescence map-based cloning TaNAM-A1 transcription factor Triticum aestivum

Passive imaging through dense scattering media

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第1期12卷 134-140页

作者： YAOMING BIAN FEI WANG YUANZHE WANG ZHENFENG FU HAISHAN LIU HAIMING YUAN GUOHAI SITU Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China

Imaging through non-static and optically thick scattering media such as dense fog,heavy smoke,and turbid water is crucial in various ***,most existing methods rely on either active and coherent light illumination,or image priors,preventing their application in situations where only passive illumination is *** this study we present a universal passive method for imaging through dense scattering media that does not depend on any prior *** the selection of small-angle components out of the incoming information-carrying scattering light and image enhancement algorithm that incorporates timedomain minimum filtering and denoising,we show that the proposed method can dramatically improve the signal-to-interference ratio and contrast of the raw camera image in outfield experiments.

关键词： scattering media illumination

Automatic recognition of landslides based on YOLOv7 and attention mechanism

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第8期21卷 2681-2695页

作者： SONG Yewei GUO Jie WU Gaofeng MA Fengshan LI Fangrui Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation academy for Earth sciences Chinese Academy of SciencesBeijing 100029China university of chinese academy of sciences Beijing 100049China

Landslide disasters comprise the majority of geological incidents on slopes,posing severe threats to the safety of human lives and property while exerting a significant impact on the geological *** rapid identification of landslides is important for disaster prevention and control;however,currently,landslide identification relies mainly on the manual interpretation of remote sensing *** interpretation and feature recognition methods are time-consuming,labor-intensive,and challenging when confronted with complex ***,automatic landslide recognition has emerged as a pivotal avenue for future *** this study,a dataset comprising 2000 landslide images was constructed using open-source remote sensing images and *** YOLOv7 model was enhanced using data augmentation algorithms and attention *** optimization models were formulated to realize automatic landslide *** findings demonstrate the commendable performance of the optimized model in automatic landslide recognition,achieving a peak accuracy of 95.92%.Subsequently,the optimized model was applied to regional landslide identification,co-seismic landslide identification,and landslide recognition at various scales,all of which showed robust recognition ***,the model exhibits limitations in detecting small targets,indicating areas for refining the deep-learning *** results of this research offer valuable technical support for the swift identification,prevention,and mitigation of landslide disasters.

关键词： Deep learning Landslide detection Natural disasters Attention mechanism Remote sensing

Socio-scientific quantification of the comprehensive benefits of debris flow mitigation measures for villages in western Sichuan, China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第5期21卷 1598-1612页

作者： DENG Ting XU Pei LI Ming LU Yafeng WANG Yukuan LI Zhengyang SHRAVAN Kumar Ghimire Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610299China university of chinese academy of sciences Beijing 100049China

Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the specific disasterreduction effects of these measures and their economic,social and ecological benefits is yet to be *** western region of Sichuan Province frequentlysuffers from geohazards such as debris flow, and thegovernment has adopted many mitigation *** study assessed the benefits of debris flowmitigation measures and identified the key influencingfactors via a field-based study conducted in 81 villagesin western Sichuan province, China. A framework forthe evaluation of the benefits of rural debris flowmitigation measures was constructed andquantitatively evaluated using a survey. Snowballsampling was performed to recruit 81 village leadersand 468 farmers. The results showed that managementand engineering measures were the main methodsused to mitigate debris flow;ecological measures wereauxiliary. The average satisfaction scores of farmers forthese three types of measures were 4.07, 3.90, and 3.56,respectively (as measured on a five-point Likert scale).In contrast, in terms of the benefits of these mitigationmeasures, only a small proportion of villages (11.11%)obtained a high level of comprehensive benefits fromthe debris flow mitigation measures, while the majority(88.89%) received medium to low-level benefits. Toimprove this situation, we further studied and foundthat the main factors that restricted villages fromachieving high-level comprehensive benefits were theunpredictable nature of debris flows, labour forceoutflow and remoteness. Effective control measures, agood economic environment and strong governmentassistance were reported as crucial factors forimproving these comprehensive benefits. This studyprovides socio-scientific references for decisionmakingon rural debris flow mitigation measures while keeping villages at the

关键词： Mitigation measures Comprehensive benefit evaluation Debris flow Mountain development Rural areas