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物理 2024年第5期53卷 287-299页

作者：朱少平罗民兴北京应用物理与计算数学研究所北京100094 北京计算科学研究中心北京100093

美国国家点火装置的物理实验结果,跨越了热核聚变点火这一标志性的门槛,再次引起了学术界和大众对可控热核聚变研究的兴趣。文章介绍了热核聚变的基本概念、激光聚变的主要内涵和激光聚变点火研究的进展。

关键词：热核聚变激光聚变聚变点火

强度调制宽带激光对受激拉曼散射动理学爆发的抑制

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物理学报 2024年第5期73卷 228-236页

作者：刘庆康张旭蔡洪波张恩浩高妍琦朱少平北京应用物理与计算数学研究所北京100094 中国工程物理研究院研究生院北京100088 北京计算科学研究中心北京100088 上海激光等离子体研究所上海201899

激光等离子体不稳定性是困扰惯性约束聚变的难题之一.宽带激光作为抑制激光等离子体不稳定性的有效手段,近年来受到广泛关注.然而,宽带激光在动理学区域驱动的受激拉曼散射等高频不稳定性存在非线性爆发,使抑制效果不及预期.本文提出一... 详细信息

激光等离子体不稳定性是困扰惯性约束聚变的难题之一.宽带激光作为抑制激光等离子体不稳定性的有效手段,近年来受到广泛关注.然而,宽带激光在动理学区域驱动的受激拉曼散射等高频不稳定性存在非线性爆发,使抑制效果不及预期.本文提出一种外加强度调制的宽带激光模型.通过选择适当的强度调制包络,能够打断背散光在强脉冲中的放大过程,降低高强度脉冲诱发剧烈爆发的概率,并大幅减少背散光份额和热电子产额.数值模拟表明,强度调制激光对受激拉曼散射具有较好的抑制能力.对于平均功率为1.0×10^(15)W/cm^(2),带宽为0.6%的二倍频宽带激光,使用强度调制技术后,反射率下降了1个数量级,20 keV以上热电子能量份额也由7.34%下降至0.31%.上述研究证实了使用强度调制宽带激光抑制高频不稳定性的可行性,并有望为后续宽带激光驱动聚变实验设计提供参考.

关键词：惯性约束聚变动理学效应宽带激光受激拉曼散射

A Heat Transport Model Including the Effect of Non-Maxwellian Electron Distribution and Its Application in Laser Produced Plasma

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Chinese Physics Letters 1999年第7期16卷 520-522页

作者： zhu shao-ping GU Pei-jun Institute of Applied Physics and Computational Mathematics Beijing 100088

An electron heat transport model is given for studying laser-to-x-ray conversion of inertial confinement *** electron heat flux is derived based on a non-Maxwellian electron distribution,and the behavior of the heat flux is *** effect of the non-Maxwellian electron distribution on inverse bremsstrahlung heating rate and electron-ion heat transfer rate are also included in the present *** simulation results show that the effects of the non-Maxwellian electron distribution on laser absorption efficiency,laser-to-x-ray conversion efficiency and electron temperature in the coronal region are important.

关键词： Maxwell Electron distribution

Quasistatic Magnetic Field Generation by an Intense Ultrashort Laser Pulse in Underdense Plasma

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Chinese Physics Letters 2000年第10期17卷 746-748页

作者： ZHENG Chun-Yang zhu shao-ping HE Xian-Tu Institute of Applied Physics and Computational Mathematics P.O.Box 8009Beijing 100088

The quasistatic magnetic field created in the interaction of intense ultrashort laser pulses with underdense plasmas has been investigated by two-dimensional particle *** relativistic ponderomotive force and plasma wave excited in self-modulation processes can drive intense electron current mainly in the propagation *** a result,an azimuthal,multi-mega Gauss order quasi-static magnetic field can be generated around the laserbeam.

关键词： ultrashort intense Pulse

Estimating the optimal vegetation coverage for the dominant tree and shrub species over China's northwest drylands

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Science China Earth Sciences 2024年第5期67卷 1500-1517页

作者： Zhongdian ZHANG Xiaoxu JIA ping zhu Mingbin HUANG Lidong REN Ming’an shao School of Geographic Sciences Xinyang Normal UniversityXinyang 464000China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100190China Yellow River Delta Modern Agricultural Engineering Laboratory Chinese Academy of SciencesBeijing 100101China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China

Anthropogenic revegetation is an effective way to control soil erosion and restore degraded ecosystems in China's northwest drylands(NWD).However,excessive vegetation cover expansion has long been known to increase evapotranspiration,leading to reduced local water availability,which can in turn threaten the health and services of restored *** the optimal vegetation coverage(OVC)is critical for balancing the trade-off between plant growth and water consumption in water-stressed areas,yet quantitative assessments over the entire NWD are still *** this study,a modified Biome BioGeochemical Cycles(Biome-BGC)model was used to simulate the long-term(1961–2020)dynamics of actual evapotranspiration(ET_(a)),net primary productivity(NPP),and leaf area index(LAI)for the dominant non-native tree(*** and ***)and shrub(*** and ***)species at 246 meteorological sites over *** modified model incorporated the Richards equation to simulate transient unsaturated water flow in a multilayer soil module,and both soil and eco-physiological parameters required by the model were validated using field-observed ETadata for each *** distributions of OVC(given by the mean maximum LAI,LAI_(max))for the dominant species were determined within three hydrogeomorphic sub-areas(i.e.,the loess hilly-gully sub-area,the windy and sandy sub-area,and the desert sub-area).The modified Biome-BGC model performed well in terms of simulating ET_(a) dynamics for the four plant *** distributions of mean ET_a,NPP,and LAI_(max)generally exhibited patterns similar to mean annual precipitation(MAP).In the loess hilly-gully sub-area(MAP:210 to 710 mm),the OVC respectively ranged from 1.7 to 2.9 and 0.8 to 2.9 for *** and *** the windy and sandy sub-area(MAP:135 to 500 mm),the OVC ranged from 0.3 to 3.3,0.5 to 2.6 and 0.6 to 2.1for ***,*** and ***,*** the desert sub-

关键词： Optimal vegetation coverage Water balance Leaf area index Biome-BGC model Dryland

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轻介质传输中辐射热传导近似成立的判别因子

强激光与粒子束 2008年第2期20卷 291-296页

作者：沈刚朱少平北京应用物理与计算数学研究所北京100088

从辐射输运方程出发，通过递推的方法，推导并得到了包含高级修正的辐射能流表达式。利用这个表达式，分析了辐射在轻介质中传输时，辐射热传导近似的成立条件。热传导近似的成立条件总是要求温度空间变化尺度与自由程之比远大于某个值... 详细信息

从辐射输运方程出发，通过递推的方法，推导并得到了包含高级修正的辐射能流表达式。利用这个表达式，分析了辐射在轻介质中传输时，辐射热传导近似的成立条件。热传导近似的成立条件总是要求温度空间变化尺度与自由程之比远大于某个值，该值即判别因子，它表征热传导近似条件满足的苛刻程度，其值越大，热传导近似就越难满足。讨论得出；当同时考虑轫致和散射过程时，这一判别因子的值在3～60之间。并进一步分析了密度的空间变化以及1维球坐标下的半径对判别因子的影响。

关键词：辐射热传导近似辐射输运热传导方程判别因子

Identification of reservoir types in deep carbonates based on mixedkernel machine learning using geophysical logging data

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Petroleum Science 2024年第3期21卷 1632-1648页

作者： Jin-Xiong Shi Xiang-Yuan Zhao Lian-Bo Zeng Yun-Zhao Zhang Zheng-ping zhu shao-Qun Dong Key Laboratory of Exploration Technologies for Oil and Gas Resources of the Ministry of Education Yangtze UniversityWuhan4310HubeiChina School of Geosciences Yangtze UniversityWuhan430100HubeiChina College of Geosciences China University of Petroleum(Beijing)Beijing102249China Petroleum Exploration and Production Research Institute of SINOPEC Beijing100083China School of Earth Sciences and Engineering Xi'an Shiyou UniversityXi'an 710065ShaanxiChina

Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage *** cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging ***,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ***,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data *** address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,*** MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input *** particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD *** evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM ***,the built MKFD model was applied in a blind well test,and a variable importance analysis was *** comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger *** MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.

关键词： Reservoir type identification Geophysical logging data Kernel Fisher discriminantanalysis Mixedkernel function Deep carbonates

Neural network modeling and prediction of HfO2 thin film properties tuned by thermal annealing

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High Power Laser Science and Engineering 2024年第2期12卷 79-86页

作者： Min Gao Chaoyi Yin Jianda shao Meiping zhu School of Microelectronics Shanghai UniversityShanghaiChina Laboratory of Thin Film Optics Key Laboratory of Materials for High Power LaserShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhouChina

Plasma-enhanced atomic layer deposition (PEALD) is gaining interest in thin films for laser applications, and post-annealing treatments are often used to improve thin film properties. However, research to improve thin film properties is often based on an expensive and time-consuming trial-and-error process. In this study, PEALD-HfO2 thin film samples were deposited and treated under different annealing atmospheres and temperatures. The samples were characterized in terms of their refractive indices, layer thicknesses and O/Hf ratios. The collected data were split into training and validation sets and fed to multiple back-propagation neural networks with different hidden layers to determine the best way to construct the process–performance relationship. The results showed that the three-hidden-layer back-propagation neural network (THL-BPNN) achieved stable and accurate fitting. For the refractive index, layer thickness and O/Hf ratio, the THL-BPNN model achieved accuracy values of 0.99, 0.94 and 0.94, respectively, on the training set and 0.99, 0.91 and 0.90, respectively, on the validation set. The THL-BPNN model was further used to predict the laser-induced damage threshold of PEALD-HfO2 thin films and the properties of the PEALD-SiO2 thin films, both showing high accuracy. This study not only provides quantitative guidance for the improvement of thin film properties but also proposes a general model that can be applied to predict the properties of different types of laser thin films, saving experimental costs for process optimization.

关键词： laser-induced damage threshold laser thin film neural network plasma-enhanced atomic layer deposition

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噪声未知的LQG控制问题研究

控制理论与应用 2010年第8期27卷 1017-1022页

作者：钱富才朱少平刘丁西安理工大学自动化与信息工程学院

对具有未知方差的线性二次高斯（LQG）问题，本文提出了具有学习特点的对偶自适应控制方法．控制器一方面能够控制系统朝着期望的目标运行，另一方面又能对未知参数进行学习，仿真结果表明了控制方法的有效性．

关键词：鲁棒控制 LQG控制对偶控制 Kalman滤波

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不确定动态混沌系统的最优控制

物理学报 2010年第4期59卷 2250-2255页

作者：朱少平钱富才刘丁西安理工大学自动化与信息工程学院西安710048 西安财经学院统计学院西安710061

对于混沌系统的控制问题,考虑到控制系统能量限制的要求,首先确立一个二次目标函数,然后给出了求解最优控制律的一个简单方法,该方法通过求解线性二次最优控制问题,获得了混沌系统的最优控制律,避免了求解非线性Hamilton-Jacobi-Bellma... 详细信息

对于混沌系统的控制问题,考虑到控制系统能量限制的要求,首先确立一个二次目标函数,然后给出了求解最优控制律的一个简单方法,该方法通过求解线性二次最优控制问题,获得了混沌系统的最优控制律,避免了求解非线性Hamilton-Jacobi-Bellman偏微分方程(HJB方程)的困难.利用Lyapunov方法证明了闭环系统的稳定性.对统一混沌系统和Liu混沌系统的仿真结果表明了控制策略的有效性.

关键词：混沌控制状态反馈统一混沌系统 Liu混沌系统