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A Neural-network-based Alternative Scheme to Include Nonhydrostatic Processes in an Atmospheric Dynamical Core

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Advances in Atmospheric Sciences 2024年第6期41卷 1083-1099,I0002,I0003页

作者： Yang XIA Bin WANG lijuan li li liU Jianghao li li DONG Shiming XU yiyuan li Wenwen XIA Wenyu HUANG Juanjuan liU Yong WANG Hongbo liU Ye PU Yujun HE Kun XIA Ministry of Education Key Laboratory for Earth System Modeling and Department of Earth System ScienceTsinghua UniversityBeijing 100084China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Innovation Group 311020008 Southern Marine Science and Engineering Guangdong LaboratoryZhuhai 519000China Shanghai Ecological Forecasting and Remote Sensing Center Shanghai 200030China Key Laboratory of Earth System Modeling and Prediction China Meteorological AdministrationBeijing 100081China College of Ocean Sciences University of Chinese Academy of SciencesBeijing 100049China

Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostatic solver in an atmospheric dynamical *** NAS is designed to replace this solver,which can be incorporated into any hydrostatic models so that existing well-developed hydrostatic models can effectively serve for a longer *** advances in machine learning(ML)provide a potential tool for capturing the main complicated nonlinear-nonhydrostatic *** this study,an ML approach called a neural network(NN)was adopted to select leading input features and develop the *** NNs were trained and evaluated with 12-day simulation results of dry baroclinic-wave tests by the Weather Research and Forecasting(WRF)*** forward time difference of the nonhydrostatic tendency was used as the target variable,and the five selected features were the nonhydrostatic tendency at the last time step,and four hydrostatic variables at the current step including geopotential height,pressure in two different forms,and potential temperature,***,a practical NAS was developed with these features and trained layer by layer at a 20-km horizontal resolution,which can accurately reproduce the temporal variation and vertical distribution of the nonhydrostatic *** by the NN-based NAS,the improved hydrostatic solver at different horizontal resolutions can run stably for at least one month and effectively reduce most of the nonhydrostatic errors in terms of system bias,anomaly root-mean-square error,and the error of the wave spatial pattern,which proves the feasibility and superiority of this scheme.

关键词： neural network nonhydrostatic alternative scheme atmospheric model dynamical core

Environmental Change and Human Occupation during Late Pleistocene in Hunan Province， South China

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Journal of Earth Science 2024年

作者： Aipeng Guo Longjiang Mao yiyuan li Haicheng Lai Jiafu Zhang Duowen Mo School of Marine Science Nanjing University of Information Science and Technology Hunan Institute of Archaeology Institute of Scientific and Technical History Nanjing University of Information Science and Technology College of Urban and Environmental Sciences Peking University

The Paleolithic sites in South China have caused controversy regarding human behaviors in response to the rapidly shifting environment of the late Pleistocene. However， chronometric and high-resolution proxies are absent from interpreting the paleoenvironmental evolution. Here we present the chronology， grain size parameters， and geochemical elements records from the Hejialing (HJL) site in South China to reveal the crucial aspects of environmental evolution， and human occupation. The geochemical record shows that during MIS 5e–5a， northern Hunan experienced the influence of summer monsoon and maintained a warm and humid climate. The laterite layer began to develop. During MIS 4， the climate transitioned to dry and cold state， leading to the attraction of hominins to the HJL area due to the abundant water and lithic raw material resources， resulting in their establishment of a short-term camp. The HJL site was primarily inhabited by hunter-gatherer societies within a forested environment. From MIS 4 to MIS 2， Hunan experienced a prolonged period of dry and cold climatic conditions， with a brief rainfall recovery occurring in late MIS 3. Diminished vegetation and resource availability compelled human populations to broaden their activities and undertake migrations. The HJL site was abandoned amid the arid phase of MIS 2. The HJL area gradually became buried beneath eolian dust deposition (EM1) from distant sources and riverine dust from nearby sources (EM2)， and the site was informed. In MIS 1， During MIS 1， the climate shifted to a warm and humid state， marking the emergence of early agricultural practices. As an essential part of South China， the environmental evolution process and diverse survival strategies employed by hominins in Hunan are vital for explaining how the paleoenvironment drove human occupation during the Late Pleistocene.

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三体对抗中的主动防御鲁棒最优预测制导律研究

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北京理工大学学报 2024年第6期44卷 645-654页

作者：陈维义何凡李逸源董海迪海军工程大学兵器工程学院湖北武汉430030

考虑防御导弹和我方目标控制系统内部扰动和未准确建模动态特性等因素造成的不确定性影响,设计了鲁棒最优预测制导律(robust optimal predictive guidance law,ROPGL)和鲁棒协同最优预测制导律(robust cooperative optimal predictive g... 详细信息

考虑防御导弹和我方目标控制系统内部扰动和未准确建模动态特性等因素造成的不确定性影响,设计了鲁棒最优预测制导律(robust optimal predictive guidance law,ROPGL)和鲁棒协同最优预测制导律(robust cooperative optimal predictive guidance law,RCOPGL)拦截来袭寻的导弹.首先,通过对非线性运动学方程线性化和降阶得到简化后的标称系统的状态方程;其次,考虑控制系统的不确定性,建立鲁棒制导问题的模型;再次,基于动态规划方法得到最优制导问题的制导指令关系式,并利用李雅普诺夫稳定性理论证明了最优制导问题的制导指令能够使鲁棒制导问题稳定;然后,引入界值函数得到线性二次型最优制导问题,通过求解黎卡提矩阵微分方程得到制导指令;最后,对设计的制导律的性能进行仿真验证.仿真结果表明,相比于其他制导律,设计的制导律能够抑制不确定性的影响,实现防御导弹对寻的导弹的拦截.

关键词：最优制导预测制导鲁棒性不确定性主动防御

两参数麦克斯韦分布的串联系统屏蔽数据统计分析

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电子产品可靠性与环境试验 2024年第1期42卷 53-58页

作者：李懿媛王蓉华上海师范大学数理学院上海200234

在系统寿命研究中,由于数据的不可缺陷性等原因容易出现系统数据被屏蔽的现象,因此对系统进行有效的统计分析和估计具有重要的意义。针对2个元件串联系统且有屏蔽发生的场合,元件寿命服从两参数Maxwell分布且形状参数已知,给出了刻度参... 详细信息

在系统寿命研究中,由于数据的不可缺陷性等原因容易出现系统数据被屏蔽的现象,因此对系统进行有效的统计分析和估计具有重要的意义。针对2个元件串联系统且有屏蔽发生的场合,元件寿命服从两参数Maxwell分布且形状参数已知,给出了刻度参数的极大似然估计与近似区间估计,并从理论上证明了该极大似然估计的存在与唯一性,最后通过2个Monte Carlo模拟算例说明了方法的可行性。

关键词：串联系统屏蔽数据极大似然估计区间估计麦克斯韦分布蒙特卡罗

基于控制灵敏度的微电网有功无功协调二次控制方法

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综合智慧能源 2024年第2期46卷 36-42页

作者：龚伟孙丹李逸源福建华电福瑞能源发展有限公司华安水力发电厂福建漳州363800 南京国电南自电网自动化有限公司南京211153 华电(华安)供电有限公司福建漳州363800

在中低压等级的微电网中,由于线路的电阻与电抗大小十分接近,因此在潮流控制时不再呈现明显的有功与无功解耦的情况。若仍旧按照大电网中有功、无功独立调节的方式进行微电网的二次控制,则容易产生超调和振荡。为了解决该问题,提出了一... 详细信息

在中低压等级的微电网中,由于线路的电阻与电抗大小十分接近,因此在潮流控制时不再呈现明显的有功与无功解耦的情况。若仍旧按照大电网中有功、无功独立调节的方式进行微电网的二次控制,则容易产生超调和振荡。为了解决该问题,提出了一种基于控制灵敏度的微电网有功无功协调二次控制方法。首先,根据不同类型的微电网一次控制架构,推导了二次控制时控制灵敏度的计算公式;然后,基于控制灵敏度建立了以频率电压偏差最小、有功无功按比例分配为控制目标的二次规划模型,通过求解此二次规划模型得到微电网二次控制的调节量。以某实际海岛微电网为算例进行分析,通过与有功无功独立调节的二次控制相比较,证明了本文所提方法能有效提高控制的准确性与稳定性。

关键词：微电网二次控制协调控制控制灵敏度二次规划

Optimized Vertical Layers for the Hybrid Terrain-Following Coordinate Minimizing Numerical Errors in a 2D Rising Bubble Experiment near Steep Terrain

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Journal of Meteorological Research 2023年第6期37卷 896-907页

作者： Hao YANG yiyuan li Bin WANG State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China

The basic terrain-following(BTF)coordinate simplifies the lower boundary conditions of a numerical model but leads to numerical error and instability on steep *** terrain-following(HTF)coordinates with smooth slopes of vertical layers(slopeVL)generally overcome this ***,the HTF coordinate becomes very desirable for atmospheric and oceanic numerical ***,improper vertical layering in HTF coordinates may also increase the incidence of *** for the slopeVL of an HTF coordinate,this study further optimizes the HTF coordinate focusing on the thickness of vertical layers(thickVL).Four HTF coordinates(HTF1–HTF4)with similar slopeVL but different vertical transition methods of thickVL are designed,and the relationship between thickVL and numerical errors in each coordinate is compared in the classic idealized thermal convection[two-dimensional(2D)rising bubble]experiment over steep *** errors of potential temperatureθand vertical velocity w are reduced most,by approximately 70%and 40%,respectively,in the HTF1 coordinate,with a monotonic increase in thickVL according to the increasing height;however,the errors ofθincreased in all the other HTF coordinates,with nonmonotonic ***,analyses of the errors of vertical pressure gradient force(VPGF)show that due to the interpolation errors of thickVL,the inflection points in the vertical transition of thickVL induce the initial VPGF errors;therefore,the HTF1 coordinate with a monotonic increase in thickVL has the smallest errors among all the *** importantly,the temporal evolution of VPGF errors manifests top-type VPGF errors that propagate upward gradually during the time *** the HTF1 and HTF4 coordinates with a monotonic increase in thickVL near the top of the terrain can suppress this *** optimized HTF coordinate(i.e.,HTF1)can be a reference for designing a vertical thickVL in a numerical model.

关键词： hybrid terrain-following coordinate thickness of vertical layer numerical error pressure gradient force two-dimensional(2D)rising bubble experiment steep terrain

耳后筋膜瓣的改良设计及其在颅耳沟重建术中的效果

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组织工程与重建外科 2024年第2期20卷 205-207页

作者：李意源张如鸿上海交通大学医学院附属第九人民医院整复外科上海市200011

目的评价耳后筋膜的组织形态学特征,并对其进行几何学设计改良,以改善颅耳沟重建术后颅耳沟外观,并减少术后局部并发症的发生。方法对16例患者进行耳后筋膜厚度的超声测量,通过几何学设计得到耳后上筋膜瓣,并将该方法用于125例颅耳沟重... 详细信息

目的评价耳后筋膜的组织形态学特征,并对其进行几何学设计改良,以改善颅耳沟重建术后颅耳沟外观,并减少术后局部并发症的发生。方法对16例患者进行耳后筋膜厚度的超声测量,通过几何学设计得到耳后上筋膜瓣,并将该方法用于125例颅耳沟重建术。结果耳后筋膜由上至下厚度逐渐增加。耳后上筋膜瓣较传统的耳后筋膜瓣在手术操作上更简单,术后的颅耳沟形态更自然,耳后局部皮肤坏死和瘢痕增生减少。结论最大限度利用接近顶侧耳后筋膜组织设计的改良耳后上筋膜瓣,在手术效果及减少术后并发症方面均优于传统耳后筋膜瓣。

关键词：先天性小耳畸形颅耳沟重建耳后筋膜耳后上筋膜瓣

新一代火星大气模式GoPlanet-Mars V1的研制

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科学通报 2024年第10期69卷 1343-1350页

作者：董理普业李艺苑刘鸿波刘娟娟邓世雅黄叶薇刘明宇刘帅王斌中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室北京100029 中国科学院大学海洋学院青岛266400 中国科学院大学地球与行星科学学院北京100049

火星探测是当前国家高科技竞争力的标志,世界航天强国均研制火星大气模式,为登陆探测提供气象环境保障.本文描述了我国新一代火星大气模式(global open planetary atmospheric model for Mars,缩写GoPlanet-Mars,简称GoMars)的研制,其... 详细信息

火星探测是当前国家高科技竞争力的标志,世界航天强国均研制火星大气模式,为登陆探测提供气象环境保障.本文描述了我国新一代火星大气模式(global open planetary atmospheric model for Mars,缩写GoPlanet-Mars,简称GoMars)的研制,其中的动力框架完全自主研发,具有二阶精度、能保证质量守恒.GoMars引进并耦合了美国宇航局艾姆斯研究中心的火星物理过程,具备模拟沙尘、水和CO_(2)的能力.基于我国“祝融号”、美国“维京1号、2号”的实测数据以及国际火星大气全球数据集评估了GoMars,结果表明:GoMars能成功再现3个探测器记录的火星大气独特的地表气压“两峰两谷”特征;在全球地表温度、纬向急流、极区CO_(2)冰和沙尘方面,GoMars也具备良好的模拟性能,可为我国火星探测计划实施提供新的气象环境保障手段.

关键词：火星大气模式气象环境祝融号

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“跃然纸上”数字融合传播平台设计与实现

丝网印刷 2024年第1期 85-87页

作者：李一媛邢一李立浩桂林电子科技大学

AI技术作为新兴技术之一,在简化工作流程、提高工作效率方面展现出很大作用。文章介绍了AI技术基本理论,及其在数字印刷中的应用实践分析,希望为相关领域提供参考。

关键词： AI技术数字印刷应用