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1.
基于NOAA/SWPC公布的太阳活动数据,我们选取第24太阳活动峰年附近的12个连续月份(2011年7月至2012年6月)和第23太阳活动周谷年附近的12个连续月份(2005年7月至2006年6月),统计了这两段时间中太阳黑子群和耀斑的活动规律,并根据时间、黑子群分布纬度、寿命和磁场类型等对峰年和谷年进行了详细分析和比较,主要结论如下所述.(1)黑子群数随时间的变化在峰年和谷年均比较随机,峰年期间黑子数比谷年增多1.5倍左右.耀斑爆发与黑子群活动具有良好的相关性,但峰年期间存在某个月份耀斑数很少的现象,而谷年期间存在某个月份耀斑数集中增多的现象.(2)无论峰年还是谷年,δ类型黑子群的耀斑产率(耀斑总数与黑子群总数之比)最大,但β型黑子群产生的耀斑爆发最多.耀斑产率与磁场类型有密切关系,但与其所处太阳活动周中的阶段无关.(3)黑子群和耀斑的纬度分布的南北不对称性,以X级耀斑最为显著.峰年较谷年的耀斑数增加主要集中在C级和M级.(4)耀斑产率同黑子群寿命具有良好的相关性,但黑子群的数目同它们的寿命之间没有明显的规律.  相似文献   

2.
太阳黑子活动区与太阳耀斑和太阳质子事件的发生有紧密的关系.选取活动区特征参量包括太阳黑子群面积,磁分类,McIntosh分类,10 cm射电流量,统计和耀斑发生的产率关系;还统计了太阳活动区的位置,软X射线通量和质子事件的产率关系.对于磁分类,McIntosh分类的每一种分类类型计算了耀斑产率,对黑子群面积和10 cm射电流量和软X射线通量用函数拟合了它们和太阳耀斑和太阳质子事件的产率关系.对活动区位置采用了分段统计质子事件产率的方法.统计结果显示我们选取的活动区特征参量与太阳耀斑和质子事件有较强的相关性.统计结果可作为以后建立太阳耀斑,太阳质子事件预报模型中预报因子的选取的基础.  相似文献   

3.
为了进一步探讨太阳耀斑与太阳黑子参量的关系,本文采集了大规模的活动区黑子数据,统计其与耀斑发生的产率关系,应用得到的拟和公式对原始数据计算得到规范化后的数据集.在此基础上使用数据挖掘技术对黑子耀斑数据建立决策树模型和建立分类规则,具体描述了黑子数据和太阳耀斑之间的相关性.最后应用这两种技术对活动区未来48h是否爆发耀斑给出了预报,预报结果具有较高的准确率和较低的虚报率.  相似文献   

4.
太阳耀斑是最剧烈的太阳爆发之一,太阳耀斑能够在几分钟内对空间环境产生影响,为了更好地应对太阳耀斑爆发的空间环境效应,本文提出一种基于自动特征提取方法的太阳耀斑预报模型.该模型以太阳黑子的连续谱观测图像为输入,利用卷积神经网络的自动图像特征提取能力,建立太阳耀斑预报模型.传统的以太阳黑子特征为输入的耀斑模型需要以黑子的McIntosh分型作为输入,黑子的McIntosh分型需要人为指定,效率低并且具有一定的主观性.通过实验比较,本文提出的耀斑预报模型比传统的以太阳黑子McIntosh分型为基础的预报模型具有更好的预报准确度.总之,本文提出的太阳耀斑预报模型能够自动提取太阳黑子图像的特征,具有更高的预报效率和准确率(在48 h M级耀斑预报中,基于深度学习方法的预报模型在耀斑报准率上比传统预报模型高3.7%,在非耀斑报准率上比传统预报模型高2.8%),是一种实用性较强的太阳耀斑预报模型.  相似文献   

5.
我们分析了1972年5月25日—6月5日过日面的黑子群(McMath活动区编号11895)的形态,目的在于寻找导致耀斑爆发的因素,以便提高太阳活动预报的水平,从而较准确地预报宇航安全期和短波通讯,突然骚扰,并且为耀斑等太阳活动现象机制的研究提供线索。 我们发现本黑子群形态的主要特点是前导黑子的旋转、分裂和自行,并且前导黑子呈现的δ磁结构在黑子群过日面期间一直存在。这黑子群的复杂的磁结构可能是本活动区一系列剧烈活动的主要原因。 黑子形态的上述剧烈变化与耀斑爆发在时间上和空间上有较好的相关性。 本活动区引起的质子耀斑和质子事件发生前,黑子形态的主要特征是前异黑子的旋转和分裂,并有部分旋涡半影结构。磁场结构的特点是黑子群磁极性排列的倒置、δ磁结构的存在和磁场梯度的剧烈变化。这表明质子耀斑和质子事件的发生同这些现象有一定的物理联系。 5月29日以后,前导黑子的逆时针旋转,可能主要是由于不对称半影使黑子自行的结果。  相似文献   

6.
基于RBF人工神经网络的生活污水处理软测量方法   总被引:4,自引:0,他引:4  
为实现城市生活污水处理的在线控制,提出了基于RBF人工神经网络的软测量方法.运用大量实测数据对RBF神经网络进行了训练和仿真.结果表明,基于RBF神经网络的软测量模型对污水处理指标BOD的实时控制具有实用价值.  相似文献   

7.
利用三亚台站2013年电离层foF2观测数据,讨论了电离层foF2的混沌特性及其预测.采用改进的C-C算法确定时间延迟和嵌入维数,计算最大李雅普诺夫指数,定量地印证foF2时间序列具有混沌特性.基于RBF神经网络的方法对foF2参量进行短期预报,并将预报结果与Volterra模型、IRI模型和实测数据进行对比.结果表明,采用RBF神经网络法可成功预测foF2的变化,相比于国际参考电离层模型有较大提高,较Volterra模型也有一定提升.在一定时间尺度内,RBF神经网络预测结果较为准确,预测误差较小,超出该预测范围,预测效果将变差.  相似文献   

8.
为了更好地模拟与预测河流水质,运用人工神经网络的原理与方法,在分析河流多河段水质模型基础上,建立了RBF人工神经网络水质模型,应用滏阳河邯郸市区段实测水质数据对模型进行训练与检验,结果表明,该模型应用于水质模拟精度高,是可行的.  相似文献   

9.
转炉终点锰预报模型的开发   总被引:1,自引:0,他引:1  
探讨转炉炼钢终点锰预报模型的建模技术 模型分为两种 :代数学模型和人工神经网络模型 代数学模型采用多元线性回归方法建模 ,该模型简单、可视 ,但仿真结果并不理想 人工神经网络模型在选取适当输入参数的基础上 ,通过对转炉生产的历史数据进行训练 ,求得合理优化的网络权重 ,可对转炉终点锰含量进行离线预报 ,该模型的仿真结果很好 ,当预报误差精度|ΔMn|≤ 0 .0 2 5 %时 ,预报命中率超过 95 % ,为今后转炉的在线锰预报和快速出钢模型的研制提供依据和技术支持  相似文献   

10.
结合太阳耀斑与日冕物质抛射参量作为预报因子建立太阳质子事件预报模型。描述太阳耀斑的三个特征参量包括耀斑峰值流量、持续时间和耀斑维度;太阳质子事件的三个特征参量分别为CME宽度、CME速度和测量位置角度。首先使用信息增益率评价各参量对质子事件发生的重要度,结果表明相比于耀斑峰值流量和持续时间,CME宽度和速度对质子事件发生具有更高的重要性。基于上述参量,应用线性Logistic回归方法建立质子事件预报模型。对模型进行检测并与只选用耀斑参量的预报模型的预报结果进行比较,结果显示采用耀斑结合CME参量的预报模型具有较高的预报准确率和较低的虚报率,尤其对于质子事件发生的报准率提高较多(67.5%上升到90%)。实验结果验证CME参量作为预报因子的有效性。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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