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Resistive field generation in intense proton beam interaction with solid targets

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Matter and Radiation at Extremes 2024年第1期9卷 35-43页

作者： W.Q.Wang J.J.Honrubia Y.Yin X.H.Yang F.Q.Shao department of Physics National University of Defense TechnologyHunanChina ETSI Aeronáutica y del Espacio Universidad Politécnica de MadridMadridSpain department of Nuclear Science and Technology National University of Defense TechnologyHunanChina

The Brown-Preston-Singleton(BPS)stopping power model is added to our previously developed hybrid code to model ion beam-plasma *** simulations show that both resistive field and ion scattering effects are important for proton beam transport in a solid target,in which they compete with each *** the target is not completely ionized,the self-generated resistive field effect dominates over the ion scattering ***,when the target is completely ionized,this situation is ***,it is found that Ohmic heating is important for higher current densities and materials with high *** energy fraction deposited as Ohmic heating can be as high as 20%-30%.Typical ion divergences with half-angles of about 5°-10°will modify the proton energy deposition substantially and should be taken into account.

关键词： interaction beam intense

Sensitivity of ghost imaging compared to conventional imaging [Invited]

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Chinese Optics Letters 2024年第6期22卷 15-32页

作者： Long-Kun Du Shuai Sun Yao-Kun Xu Hui-Zu Lin Ning-Yi Leng Wei-Tao Liu Institute for Quantum Science and Technology College of ScienceNational University of Defense TechnologyChangsha 410073China Interdisciplinary Center of Quantum Information National University of Defense TechnologyChangsha 410073China Hunan Key Laboratory of Mechanism and Technology of Quantum Information Changsha 410073China College of Electronic Science and Technology National University of Defense TechnologyChangsha 410073China department of Mathematics College of ScienceNational University of Defense TechnologyChangsha 410073China

Ghost imaging has been attracting more and more attention, which provides a way to obtain images of objects with only a single-pixel detector. Considering possible applications, it becomes urgent to clarify the sensitivity of ghost imaging. Due to the unique characteristics of single-pixel detectors, which collect photons without distributing them to multiple pixels,often outperforming array sensors, ghost imaging is believed to be more sensitive than conventional imaging. However,a systematic analysis on the sensitivity of ghost imaging is yet to be completed. In this paper, we present a method for quantitatively assessing the sensitivity of ghost imaging. A detailed comparison is provided between ghost imaging and conventional imaging, taking into account the particle nature of photons and the noise of detection. With the settings of the two imaging methods being the same to the most extent, the minimal required number of detected photons for images of a certain quality is considered. For the thermal source version, ghost imaging demonstrates enhanced sensitivity under practical situations, with noise *** an entangled source, ghost imaging surpasses conventional imaging techniques in terms of sensitivity obviously. In one word, ghost imaging promises higher sensitivity at low photon flux and noisy situations.

关键词： sensitivity ghost imaging conventional imaging

A Two-Layer Encoding Learning Swarm Optimizer Based on Frequent Itemsets for Sparse Large-Scale Multi-Objective Optimization

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1342-1357页

作者： Sheng Qi Rui Wang Tao Zhang Xu Yang Ruiqing Sun Ling Wang College of Systems Engineering National University of Defense TechnologyChangsha 410073China Xiangjiang Laboratory Changsha 410205China College of Computer National University of Defense TechnologyChangsha 410073China department of Automation Tsinghua UniversityBeijing 100084China IEEE

Traditional large-scale multi-objective optimization algorithms(LSMOEAs)encounter difficulties when dealing with sparse large-scale multi-objective optimization problems(SLM-OPs)where most decision variables are *** a result,many algorithms use a two-layer encoding approach to optimize binary variable Mask and real variable Dec ***,existing optimizers often focus on locating non-zero variable posi-tions to optimize the binary variables ***,approxi-mating the sparse distribution of real Pareto optimal solutions does not necessarily mean that the objective function is *** data mining,it is common to mine frequent itemsets appear-ing together in a dataset to reveal the correlation between *** by this,we propose a novel two-layer encoding learning swarm optimizer based on frequent itemsets(TELSO)to address these *** mined the frequent terms of multiple particles with better target values to find mask combinations that can obtain better objective values for fast ***-mental results on five real-world problems and eight benchmark sets demonstrate that TELSO outperforms existing state-of-the-art sparse large-scale multi-objective evolutionary algorithms(SLMOEAs)in terms of performance and convergence speed.

关键词： Evolutionary algorithms learning swarm optimiza-tion sparse large-scale optimization sparse large-scale multi-objec-tive problems two-layer encoding.

Color coded metadevices toward programmed terahertz switching

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Light(Science & Applications) 2024年第7期13卷 1383-1392页

作者： Weibao He Xiang’ai Cheng Siyang Hu Ziheng Ren Zhongyi Yu Shun Wan Yuze Hu Tian Jiang College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangshaChina. Nanhu Laser Laboratory National University of Defense TechnologyChangshaChina. Hunan Provincial Key Laboratory of High Energy Laser Technology National University of Defense TechnologyChangshaChina. Institute for Quantum Science and Technology College of ScienceNational University of Defense TechnologyChangshaChina

Terahertz modulators play a critical role in high-speed wireless communication,non-destructive imaging,and so on,which have attracted a large amount of research ***,all-optical terahertz modulation,an ultrafast dynamical control approach,remains to be limited in terms of encoding and *** we experimentally demonstrated an optical-programmed terahertz switching realized by combining optical metasurfaces with the terahertz metasurface,resulting in 2-bit dual-channel terahertz *** terahertz metasurface,made up of semiconductor islands and artificial microstructures,enables effective all-optical programming by providing multiple frequency channels with ultrafast modulation at the nanosecond ***,optical metasurfaces covered in terahertz metasurface alter the spatial light field distribution to obtain color *** to the time-domain coupled mode theory analysis,the energy dissipation modes in terahertz metasurface can be independently controlled by color excitation,which explains the principle of 2-bit encoding *** work establishes a platform for all-optical programmed terahertz metadevices and may further advance the application of composite metasurface in terahertz manipulation.

关键词： terahertz surface excitation

αDecay in extreme laser fields within a deformed Gamow-like model

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Nuclear Science and Techniques 2024年第2期35卷 131-144页

作者： Qiong Xiao Jun-Hao Cheng Yang-Yang Xu You-Tian Zou Jun-Gang Deng Tong-Pu Yu department of Physics National University of Defense TechnologyChangsha 410073China College of Science China Three Gorges UniversityYichang 443002China

In this study, the effect of extreme laser fields on the α decay process of ground-state even–even nuclei was *** the deformed Gamow-like model, we found that state-of-the-art lasers can cause a slight change in the α decay penetration probability of most nuclei. In addition, we studied the correlation between the rate of change of the α decay penetration probability and angle between the directions of the laser electric field and α particle emission for different nuclei. Based on this correlation, the average effect of extreme laser fields on the half-life of many nuclei with arbitrary α particle emission angles was calculated. The calculations show that the laser suppression and promotion effects on the α decay penetration probability of the nuclei population with completely random α particle-emission directions are not completely *** remainder led to a change in the average penetration probability of the nuclei. Furthermore, the possibility of achieving a higher average rate of change by altering the spatial shape of the laser is explored. We conclude that circularly polarized lasers may be helpful in future experiments to achieve a more significant average rate of change of the α decay half-life of the nuclei population.

关键词： αDecay Deformed Gamow-like model Half-lives Extreme laser field Penetration probability

High-power mode-programmable orbital angular momentum beam emitter with an internally sensed optical phased array

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Chinese Optics Letters 2024年第2期22卷 120-127页

作者：龙金虎邓宇高志强常洪祥常琦马阎星吴坚粟荣涛马鹏飞周朴 College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China Hunan Provincial Key Laboratory of High Energy Laser Technology National University of Defense TechnologyChangsha 410073China

The high-power mode-programmable orbital angular momentum(OAM)beam has attracted significant attention in a wide range of applications,such as long-distance optical communication,nonlinear frequency conversion,and beam *** beam combining(CBC)of an optical phased array(OPA)can offer a promising solution for both generating the high-power OAM beam and rapidly switching the OAM ***,achieving real-time phase noise locking and formation of desired phase structures in a high-power CBC system faces significant ***,an internal phase-sensing technique was utilized to generate the high-power OAM beam,which effectively mitigated thermal effects and eliminated the need for large optical *** OPA with six elements was employed for experimental *** first effective generation of over 1.5 kW mode-programmable OAM beam in a continuous-wave domain was ***,the results demonstrated that the generated OAM beam could be modulated with multiple *** topological charge can be switched in real time from-1 ***,this OAM beam emitter could function as an OAM beam copier by easily transforming a single OAM beam into an OAM beam *** importantly,a comprehensive analysis was conducted on power scaling,mode switching speed,and expansion of OAM ***,the system’s compact design enabled it to function as a packageable OAM beam *** to the advantages of having high power and programmable modes with multiple dimension modulation in phase structures and intensity distribution,this work can pave the way for producing high-power structured light beams and advancing their applications.

关键词： orbital angular momentum optical vortex optical phased array coherent beam combining

The“depict”strategy for discovering new compounds in complex matrices:Lycibarbarspermidines as a case

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Journal of Pharmaceutical analysis 2024年第3期14卷 416-426页

作者： Chen Han Zhixin Zhang Zhiyang Feng Chuanjia Zhai Xuejiao Li Yulian Shi Xiang Li Miao Li Ying Wang Gan Luo Xiaoyan Gao department of Chinese Medicine analysis School of Chinese Materia MedicaBeijing University of Chinese MedicineBeijing102488China

The comprehensive detection and identification of active ingredients in complex matrices is a crucial *** chromatography coupled with high-resolution mass spectrometry(LC-HRMS)is the most prominent analytical platform for the exploration of novel active compounds from complex ***,the LC-HRMS-based analysis workflow suffers from several bottleneck issues,such as trace content of target compounds,limited acquisition for fragment information,and uncertainty in interpreting relevant MS2 *** are vital antioxidant active ingredients in Lycii Fructus,while the reported structures are merely focused on dicaffeoylspermidines due to their low *** comprehensively detect the new structures of lycibarbarspermidine derivatives,a“depict”strategy was developed in this ***,potential new lycibarbarspermidine derivatives were designed according to the biosynthetic pathway,and a comprehensive database was established,which enlarged the coverage of lycibarbarspermidine ***,the polarity-oriented sample preparation of potential new compounds increased the concentration of the target ***,the construction of the molecular network based on the fragmentation pathway of lycibarbarspermidine derivatives broadened the comprehensiveness of ***,the weak response signals were captured by data-dependent scanning(DDA)followed by parallel reaction monitoring(PRM),and the efficiency of acquiring MS2 fragment ions of target compounds was significantly *** on the integrated strategy above,210 lycibarbarspermidine derivatives were detected and identified from Lycii Fructus,and in particular,170 potential new compounds were structurally *** integrated strategy improved the sensitivity of detection and the coverage of low-response components,and it is expected to be a promising pipeline for discovering new compounds.

关键词： Mass spectrometric detection Weak response signals Complex matrices Novel lycibarbarspermidines

Learning to Branch in Combinatorial Optimization With Graph Pointer Networks

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 157-169页

作者： Rui Wang Zhiming Zhou Kaiwen Li Tao Zhang Ling Wang Xin Xu Xiangke Liao IEEE the Xiangjiang Laboratory and the College of Systems Engineering National University of Defense TechnologyChangsha 410073China the Institute of Automation Chinese Academy of SciencesBeijing 100190China the College of Systems Engineering National University of Defense TechnologyChangsha 410073 the Hunan Key Laboratory of Multi-Energy System Intelligent Interconnection Technology Changsha 410073China the department of Automation Tsinghua UniversityBeijing 100084China the College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China the College of Computer Science and Technology National University of Defense TechnologyChangsha 410073China

Traditional expert-designed branching rules in branch-and-bound(B&B) are static, often failing to adapt to diverse and evolving problem instances. Crafting these rules is labor-intensive, and may not scale well with complex *** the frequent need to solve varied combinatorial optimization problems, leveraging statistical learning to auto-tune B&B algorithms for specific problem classes becomes attractive. This paper proposes a graph pointer network model to learn the branch rules. Graph features, global features and historical features are designated to represent the solver state. The graph neural network processes graph features, while the pointer mechanism assimilates the global and historical features to finally determine the variable on which to branch. The model is trained to imitate the expert strong branching rule by a tailored top-k Kullback-Leibler divergence loss function. Experiments on a series of benchmark problems demonstrate that the proposed approach significantly outperforms the widely used expert-designed branching rules. It also outperforms state-of-the-art machine-learning-based branch-and-bound methods in terms of solving speed and search tree size on all the test instances. In addition, the model can generalize to unseen instances and scale to larger instances.

关键词： Branch-and-bound(B&B) combinatorial optimization deep learning graph neural network imitation learning

Operational requirements analysis method based on question answering of WEKG

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Journal of Systems Engineering and Electronics 2024年第2期35卷 386-395页

作者： ZHANG Zhiwei DOU Yajie XU Xiangqian MA Yufeng JIANG Jiang TAN Yuejin College of Systems Engineering National University of Defense TechnologyChangsha 410073China

The weapon and equipment operational requirement analysis(WEORA) is a necessary condition to win a future war,among which the acquisition of knowledge about weapons and equipment is a great challenge. The main challenge is that the existing weapons and equipment data fails to carry out structured knowledge representation, and knowledge navigation based on natural language cannot efficiently support the WEORA. To solve above problem, this research proposes a method based on question answering(QA) of weapons and equipment knowledge graph(WEKG) to construct and navigate the knowledge related to weapons and equipment in the WEORA. This method firstly constructs the WEKG, and builds a neutral network-based QA system over the WEKG by means of semantic parsing for knowledge navigation. Finally, the method is evaluated and a chatbot on the QA system is developed for the WEORA. Our proposed method has good performance in the accuracy and efficiency of searching target knowledge, and can well assist the WEORA.

关键词： operational requirement analysis weapons and equipment knowledge graph(WEKG) question answering(QA) neutral network