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Prediction of solar activities: Sunspot numbers and solar magnetic synoptic maps

Science China Earth Sciences 2024年第8期67卷 2460-2477页

作者： Rui ZHUO Jiansen HE Die DUAN Rong LIN Ziqi WU limei yan Yong WEI School of Earth and Space Sciences Peking University College of Advanced Interdisciplinary Studies National University of Defense Technology Centre for Mathematical Plasma Astrophysics Department of MathematicsKU Leuven Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences

The evolution of solar magnetic fields is significant for understanding and predicting solar activities. And our knowledge of solar magnetic fields largely depends on the photospheric magnetic field. In this paper, based on the spherical harmonic expansion of the photospheric magnetic field observed by Wilcox Solar Observatory, we analyze the time series of spherical harmonic coefficients and predict Sunspot Number as well as synoptic maps for Solar Cycle 25. We find that solar maximum years have complex short-period disturbances, and the time series of coefficient g7～0 is nearly in-phase with Sunspot Number, which may be related to solar meridional circulation. Utilizing Long Short-Term Memory networks（LSTM）, our prediction suggests that the maximum of Solar Cycle 25 is likely to occur in June 2024 with an error of 8 months, the peak sunspot number may be 166.9±22.6, and the next solar minimum may occur around January 2031. By incorporating Empirical Mode Decomposition, we enhance our forecast of synoptic maps truncated to Order 5, validating their relative reliability. This prediction not only addresses a gap in forecasting the global distribution of the solar magnetic field but also holds potential reference value for forthcoming solar observation plans.

关键词： Solar activity prediction Solar magnetic field Spherical harmonic expansion Long-Short Term Memory (LSTM) Empirical Mode Decomposition (EMD)

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Effects of natural forest conversion and plantation tree species composition on soil macrofauna communities in Northeast China mountains

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林业研究:英文版 2023年第5期34卷 1475-1489页

作者： Shuangjiao Ma Qingcheng Wang Yong Zhang limei yan Donghai Cui Liqing Xu Key Laboratory for Sustainable Forest Ecosystem Management−Ministry of Education School of ForestryNortheast Forestry UniversityHarbin 150040People’s Republic of China

As primary and secondary forests are being replaced by plantations across the globe,the soil macrofauna community structure is also affected,but little is known about the impact of mixed culture plantations compared with monocultures on the soil macrofauna.To determine the impact of forest conversion on soil macrofauna,we surveyed the soil macrofauna in two broad-leaved and three coniferous monoculture stands and four coniferous-broadleaved mixed stands,and in adjacent reserved secondary stands as a reference.Soil macro fauna community composition was significant affected by forest type,season and their interaction(P<0.05).The abundance,taxa richness and diversity of soil macro fauna changed to different degrees depending on the plantation type.Broadleaved monoculture stands and secondary stands had similar macrofauna abundance and taxa richness,but values were lower in coniferous stands than in secondary stands.The Shannon index for macrofauna in coniferous stands was also the lowest,but the Pielou index did not differ between forest types.The negative effects of the conifer monoculture on soil macro fauna were not present in the mixed stands with broad-leaved trees.Forest conversion impacted soil properties;soil moisture,NO_(3)^(-),and pH were significant drivers of soil macrofauna community structure.The impact of forest conversion on soil macrofauna was closely dependent on tree species composition and diversity.The macro fauna community structure in the broadleaved and the mixed stands were relatively similar to that in the natural forest,and thus recommended for forest conversion in the study area.

关键词： Forest conversion Plantation forest Tree species composition Soil macrofauna Diversity Functional group

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Observational evidences of wave excitation and inverse cascade in a distant Earth foreshock region

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Science China Earth Sciences 2019年第4期62卷 619-630页

作者： Jiansen HE Die DUAN Xingyu ZHU limei yan Linghua WANG School of Earth and Space Sciences Peking University Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

The foreshock with nascent plasma turbulence is regarded as a fascinating region to understand basic plasma physical processes, e.g., wave-particle interactions as well as wave-wave couplings. Although there have been plenty of intensive studies on this topic, some key clues about the physical processes still lack observations. A relatively comprehensive case study with some new observations is presented in this work based on the WIND spacecraft observations. In this case, upstream energetic protons were drifting at tens of Alfvén speed with respect to the background plasma protons. When looking at the magnetic wave activities, we find the co-existence of high-frequency(0.1-0.5 Hz) large-amplitude right-hand polarized(RHP) waves and lowfrequency(0.02-0.1 Hz) small-amplitude left-hand polarized(LHP) waves in the spacecraft(SC) frame. The observed anticorrelation between magnetic and velocity fluctuations along with the sunward magnetic field direction indicates that the lowfrequency LHP waves in the SC frame are in fact the sunward upstream RHP Alfvénic waves in the solar wind frame. This new observation corroborates the applicability of theories about plasma non-resonance instability and inverse cascade to the foreshock region, where the downstream high-frequency RHP parent waves are excited by the upstream energetic protons through non-resonance instability and the low-frequency RHP daughter waves are generated by the parent waves due to nonlinear parametric instability. Furthermore, enhanced downstream energetic proton fluxes are inferred to result from scattering of the upstream protons by the nascent turbulent fluctuations. Therefore, some critical clues about the newborn turbulence in the foreshock are provided in this work.

关键词： Solar wind Foreshock Wave-particle interaction Parametric instability

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基于谱聚类的主动配电网多时间尺度无功优化策略

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浙江电力 2024年第2期43卷 58-68页

作者：闫丽梅丁泽华东北石油大学电气信息工程学院黑龙江大庆163318

高比例分布式光伏接入配电网后,传统优化方案无法有效平抑电压波动,分布式光伏逆变器的无功调控能力难以充分利用。为此,提出一种基于谱聚类的主动配电网多时间尺度无功优化策略,该方法分为日前优化和日内实时优化两个阶段。首先,对离... 详细信息

高比例分布式光伏接入配电网后,传统优化方案无法有效平抑电压波动,分布式光伏逆变器的无功调控能力难以充分利用。为此,提出一种基于谱聚类的主动配电网多时间尺度无功优化策略,该方法分为日前优化和日内实时优化两个阶段。首先,对离散设备的时间耦合性进行解耦,以配电网网损、平均电压偏差、电压波动严重程度为目标函数,建立基于社交网络搜索算法的日前无功优化模型,确定离散设备静态最优档位序列;其次,通过谱聚类的方法进行耦合,确定离散设备动态最优档位序列,结合改进的分布式光伏逆变器就地控制策略,建立日内实时优化模型,从而抑制日前预测数据偏差导致的电压波动;最后,基于改进后的IEEE33节点系统进行仿真实验。仿真结果表明,所提策略可以有效降低运算难度、提高求解效率,验证了该策略的有效性和优越性。

关键词：主动配电网多时间尺度动态无功优化谱聚类解耦方法社交网络搜索算法

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The solar wind plasma upstream of Mars observed by Tianwen-1:Comparison with Mars Express and MAVEN

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Science China Earth Sciences 2022年第4期65卷 759-768页

作者： Kai FAN limei yan Yong WEI Aibing ZHANG Linggao KONG Markus FRÄNZ Fei HE Lihui CHAI Chongjing YUAN Yuqi WANG Jun ZHONG Zhaojin RONG Zhonghua YAO Yongxin PAN Jun CUI Jiansen HE Wenya LI Binbin TANG Chi WANG Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China National Space Science Center Chinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of Space Environment Exploration Beijing 100190China Key Laboratory of Science and Technology on Space Environment Situational Awareness Chinese Academy of SciencesBeijing 100190China Max-Planck-Institute for Solar System Research Goettingen 37077Germany State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China School of Atmospheric Sciences Sun Yat-Sen UniversityZhuhai 519082China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China

On the great journey to Mars,China’s first planetary exploration mission,the Tianwen-1 came within 26 million kilometers of Mars from 31 October 2020 to 25 January 2021 and was getting closer to its destination,the red planet,in search of answers to the cataclysmic climate change that occurred in Martian history.Both the escape of the Martian atmosphere and the loss of surface water were firmly influenced by solar activities.Tianwen-1 provided a unique chance to depict the solar wind streams between Earth and Mars during the minimum of Solar Cycle 25.During the three-month cruise phase of Tianwen-1,the solar wind flows were successively observed at Earth,Tianwen-1,and Mars.After the field of view correction and noise reduction,the solar wind velocity and density measured by Tianwen-1 show good agreement with those at Earth and Mars.The results indicate that the performance of the ion analyzer onboard the Tianwen-1 orbiter is reliable and stable.It is worth looking forward to the joint observations of ion escape with other Mars probes in the following Martian years.

关键词： Tianwen-1 Mars Plasma moment Solar wind

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含电动汽车和光伏的配电网演化动态博弈调度策略

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太阳能学报 2024年第5期45卷 316-323页

作者：闫丽梅曾家威徐建军彭程赵书琪贾莹东北石油大学电气工程信息学院大庆163318

针对大规模电动汽车的无序充电行为可能导致电网出现的三相不平衡问题,基于演化动态博弈模型,提出一种考虑三相负荷平衡和光伏消纳的电动汽车充电调度策略。首先,基于电动汽车接入时段的主观性以及光伏出力和负荷的不确定性,引入游牧集... 详细信息

针对大规模电动汽车的无序充电行为可能导致电网出现的三相不平衡问题,基于演化动态博弈模型,提出一种考虑三相负荷平衡和光伏消纳的电动汽车充电调度策略。首先,基于电动汽车接入时段的主观性以及光伏出力和负荷的不确定性,引入游牧集群和定居集群之间的演化动态博弈方程;然后,考虑用户侧和电网侧双方利益关系,设计以最小化电动汽车充电费用、三相负荷不平衡度和无功需求为目标的调度优化模型;最后,通过对某商业区配电网算例进行仿真求解,对比分析三相有功曲线、三相无功曲线以及荷电状态曲线的变化趋势。算例结果表明,该调度策略可有效降低三相不平衡度,满足无功补偿的需求以及改善用户充电成本。

关键词：光伏发电配电网电动汽车功率控制负荷管理无功补偿演化动态博弈

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基于“久病入络”理论探讨通窍活血汤对缺血性卒中后继发性癫痫的疗效及脑血流动力学的影响

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辽宁中医杂志 2024年第2期51卷 106-110页

作者：郭明迪刘姿瑶张小倩阎丽媚中国医科大学附属第一医院辽宁沈阳110001 辽宁中医药大学附属医院辽宁沈阳110032

目的基于“久病入络”理论探讨通窍活血汤对缺血性卒中后继发性癫痫患者的疗效及脑血流动力学的影响。方法选取2018年1月—2020年1月该院收治的缺血性卒中后继发性癫痫患者80例,依据随机数字表分两组,各40例。对照组给予卡马西平;在此... 详细信息

目的基于“久病入络”理论探讨通窍活血汤对缺血性卒中后继发性癫痫患者的疗效及脑血流动力学的影响。方法选取2018年1月—2020年1月该院收治的缺血性卒中后继发性癫痫患者80例,依据随机数字表分两组,各40例。对照组给予卡马西平;在此基础上,观察组给予通窍活血汤,持续治疗2周。比较两组患者的临床疗效,治疗前后测定脑血流动力学、血液流变学及氧化应激指标,记录不良反应。结果对照组患者的总有效率[85.00%(34/40)]低于观察组[97.50%(39/40)],对比有统计学意义(P0.05)。结论基于“久病入络”理论使用通窍活血汤对缺血性卒中后继发性癫痫患者的疗效显著,可以改善脑血流动力学和血液流变学,抑制氧化应激,且安全性高,值得推广。

关键词：久病入络通窍活血汤继发性癫痫脑血流动力学血液流变学氧化应激

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火星全大气模式与沙尘活动模拟研究:回顾与展望

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科学通报 2024年第8期69卷 1058-1067页

作者：周旭魏勇吴兆朋任志鹏谭宁范斯腾何飞戎昭金闫丽梅王誉棋范开高佳维中国科学院地质与地球物理研究所中国科学院地球与行星物理重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院地质与地球物理研究所中国科学院新生代地质与环境重点实验室北京100029 南方科技大学地球与空间科学系深圳518055

基于火星全大气模式的数值模拟研究有助于深入理解火星陆面-大气-空间环境多圈层相互耦合过程,是当今国际研究热点.模式对整个火星大气区域气象要素的描述亦可作为保障火星探测活动顺利开展的重要参考依据.沙尘活动显著影响着火星气候... 详细信息

基于火星全大气模式的数值模拟研究有助于深入理解火星陆面-大气-空间环境多圈层相互耦合过程,是当今国际研究热点.模式对整个火星大气区域气象要素的描述亦可作为保障火星探测活动顺利开展的重要参考依据.沙尘活动显著影响着火星气候与天气变化,也对火星表面探测器可造成巨大安全威胁.对沙尘活动及其影响完善的模拟是目前全大气模式开发与研究工作中的重点之一.本文回顾了火星全大气模式的发展历程,概述了其构建方法,总结了相关科研成果,多角度论述了自主发展火星全大气模式的重要科研与工程价值,建议以火星沙尘活动为重点研究方向,牵引我国火星全大气模式的自主研发.模式的开发与应用涉及行星科学、空间科学、大气科学、计算机科学多领域协同合作.其开发过程势必带动我国行星科学全面发展,为相关研究领域积累经验、储备人才.

关键词：火星全大气模式数值模拟火星沙尘暴火星多圈层耦合

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应变式弹性成像和剪切波弹性成像联合BI-RADS 对乳腺肿块性质的判断价值

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中华全科医学 2024年第3期22卷 473-477页

作者：严立妹葛宜兵吴正升武警安徽总队医院特检科安徽合肥230001 合肥市第二人民医院特检科安徽合肥230012

目的探讨应变式弹性成像和剪切波弹性成像技术分别联合乳腺超声影像报告和数据系统(BI-RADS)对乳腺肿块性质良恶性的诊断价值。方法回顾性分析2021年4月—2023年3月合肥市第二人民医院收治的105例乳腺肿块患者(共105个病灶)的临床病... 详细信息

目的探讨应变式弹性成像和剪切波弹性成像技术分别联合乳腺超声影像报告和数据系统(BI-RADS)对乳腺肿块性质良恶性的诊断价值。方法回顾性分析2021年4月—2023年3月合肥市第二人民医院收治的105例乳腺肿块患者(共105个病灶)的临床病理资料,术前接受常规超声检查、应变式弹性成像和剪切波弹性成像检查。以病理结果为金标准将病灶分为良性组(64例)和恶性组(41例),比较2组弹性应变率比值(SR)、剪切波最大弹性模量值(Emax),绘制ROC曲线评估BI-RADS、SR、Emax及联合诊断恶性乳腺肿块的效能。结果 105例乳腺肿块患者经病理检查显示,共41例(39.05%)恶性肿块,64例(60.95%)良性肿块。BI-RADS分类结果显示,2类10例,3类16例,4a类21例,4b类19例,4c类18例,5类21例。以4b分类及以上诊断为恶性,BI-RADS分类诊断恶性乳腺肿块的灵敏度为92.68%,特异度为68.75%。恶性组SR、Emax值均高于良性组(P<0.05)。ROC曲线分析显示,SR、Emax诊断恶性乳腺肿块的AUC分别为0.739、0.784,最佳截断值分别为4.17%、98.21 kPa;SR+Emax联合诊断的AUC为0.861,灵敏度为70.73%,特异度为92.19%,约登指数为0.629,联合诊断效能高于单项诊断(P<0.05)。ROC曲线分析显示,SR+BI-RADS、Emax+BI-RADS、SR+Emax+BI-RADS诊断恶性乳腺肿块的AUC分别为0.826、0.830、0.892,SR+Emax+BI-RADS诊断效能高于SR+BI-RADS、Emax+BI-RADS、BI-RADS(P<0.05)。结论 SR+Emax+BI-RADS联合诊断能明显提高乳腺癌的诊断效能,提高了BI-RADS分类诊断的特异度。

关键词：应变式弹性成像剪切波弹性成像乳腺超声影像报告和数据系统乳腺肿块诊断

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Development of High Efficient and Low Toxic Oil Spill Dispersants based on Sorbitol Derivants Nonionic Surfactants and Glycolipid Biosurfactants

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Journal of Environmental Protection 2013年第1期4卷 16-22页

作者： Dandan Song Shengkang Liang Qianqian Zhang Jiangtao Wang limei yan Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Qingdao 266100 China College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China

Dispersants, usually blending with several surfactants and a solvent, are used to enhance oil spill dispersion as small droplets in water column. Although there is growing acceptance of dispersants as a counter measure to marine oil spills around the world, the two major issues with the dispersants are their toxicity to marine life and dispersion effectiveness (DE) for crude-oil, especially for heavy oil. To develop more efficient and less toxic dispersants, two kinds of sorbitol derivant nonionic surfactant (polysorbate 85 and sorbeth-40 tetraoleate), two kinds of glycolipid biosurfactants (rhamnolipid and sophorolipid) and less toxic solvent ethylene glycol butyl ether were chosen in this study, and two dispersant formulations were optimized by uniform design methods. Effects of dispersant-to-oil ratio, temperature, salinity and pH on the performance of the two optimized dispersants were investigated. The two dispersants had high dispersion effectiveness (DE) for heavy crude oil, while both dispersants keep high DE at the dispersant-to-oil ratio below 1:25 and the temperature above 5 ℃. In addition, the two dispersants also performed well in a wide range of salinity and pH values. Finally, toxicity tests revealed that the two dispersants showed low toxicity to two kinds of fish (Danio rerio and Microgobius gulosus).

关键词： Oil spill dispersant Formula uniform design Baffled Flask Test Effectiveness Toxicity

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