Solar flare forecasting based on a Fusion Model

Solar flare prediction is an important subject in the field of space weather.Deep learning technology has greatly promoted the development of this subject.In this study,we propose a novel solar flare forecasting model integrating Deep Residual Network(ResNet)and Support Vector Machine(SVM)for both≥C-class(C,M,and X classes)and≥M-class(M and X classes)flares.We collected samples of magnetograms from May 1,2010 to September 13,2018 from Space-weather Helioseismic and Magnetic Imager(HMI)Active Region Patches and then used a cross-validation method to obtain seven independent data sets.We then utilized five metrics to evaluate our fusion model,based on intermediate-output extracted by ResNet and SVM using the Gaussian kernel function.Our results show that the primary metric true skill statistics(TSS)achieves a value of 0.708±0.027 for≥C-class prediction,and of 0.758±0.042 for≥M-class prediction;these values indicate that our approach performs significantly better than those of previous studies.The metrics of our fusion model’s performance on the seven datasets indicate that the model is quite stable and robust,suggesting that fusion models that integrate an excellent baseline network with SVM can achieve improved performance in solar flare prediction.Besides,we also discuss the performance impact of architectural innovation in our fusion model.

A Statistical Study of Magnetic Flux Emergence in Solar Active Regions Prior to Strongest Flares

Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24,we explored 100 active regions(ARs)that produced M5.0 or stronger flares.We focus on the presence/absence of the emergence of magnetic flux in these ARs 2-3 days before the strong flare onset.We found that 29 ARs in the sample emerged monotonically amidst quiet-Sun.A major emergence of a new magnetic flux within a pre-existing AR yielding the formation of a complex flare-productive configuration was observed in another 24 cases.For 30 ARs,an insignificant(in terms of the total magnetic flux of pre-existing AR)emergence of a new magnetic flux within the pre-existing magnetic configuration was observed;for some of them the emergence resulted in a formation of a configuration with a small δ-sunspot;11 out of 100 ARs exhibited no signatures of magnetic flux emergence during the entire interval of observation.In six cases the emergence was in progress when the AR appeared on the Eastern limb,so that the classification and timing of emergence were not possible.We conclude that the recent flux emergence is not a necessary and/or sufficient condition for strong flaring of an AR.The flux emergence rate of flare-productive ARs analyzed here was compared with that of flare-quiet ARs analyzed in our previous studies.We revealed that the flare-productive ARs tend to display faster emergence than the flare-quiet ones do.

The Evolution of Photospheric Current Density During an X9.3-Class Solar Flare

This paper deduced the temporal evolution of the magnetic field through a series of high-resolution vector magnetograms and calculated the fine distribution map of current density during an X9.3-class flare eruptions using Ampère's law.The results show that a pair of conjugate current ribbons exist on both sides of the magnetic neutral line in this active region,and these conjugate current ribbons persist before,during,and after the flare.It was observed that the X9.3-class flare brightened in the form of a bright core and evolved into a double-ribbon flare over time.Importantly,the position of the double-ribbon flare matches the position of the current ribbons with high accuracy,and their morphologies are very similar.By investigating the complexity of current density and flare morphology,we discovered a potential connection between the eruption of major flares and the characteristics of current density.

The Dependence between Solar Flare Emergence and the Average Background Solar X-Ray Flux Emission

Solar flares, sudden bursts of intense electromagnetic radiation from the Sun, can significantly disrupt technological infrastructure, including communication and navigation satellites. To mitigate these risks, accurate forecasting of solar activity is crucial. This study investigates the potential of the Sun’s background X-ray flux as a tool for predicting solar flares. We analyzed data collected by solar telescopes and satellites between the years 2013 and 2023, focusing on the duration, frequency, and intensity of solar flares. We compared these characteristics with the background X-ray flux at the time of each flare event. Our analysis employed statistical methods to identify potential correlations between these solar phenomena. The key finding of this study reveals a significant positive correlation between solar flare activity and the Sun’s background X-ray flux. This suggests that these phenomena are interconnected within the framework of overall solar activity. We observed a clear trend: periods with increased occurrences of solar flares coincided with elevated background flux levels. This finding has the potential to improve solar activity forecasting. By monitoring background flux variations, we may be able to develop a more effective early warning system for potentially disruptive solar flares. This research contributes to a deeper understanding of the complex relationship between solar flares and the Sun’s overall radiative output. These findings indicate that lower-resolution X-ray sensors can be a valuable tool for identifying periods of increased solar activity by allowing us to monitor background flux variations. A more affordable approach to solar activity monitoring is advised.

A Confined Two-peaked Solar Flare Observed by EAST and SDO

The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature that is deserved much more attentions.Here,we reported a confined two-peaked solar flare and analyzed the associated eruptions using high-quality observations from Educational Adaptive-optics Solar Telescope and Solar Dynamics Observatory.Before the flare,a magnetic flux rope(MFR)formed through partially tether-cutting reconnection between two sheared arches.The flare occurred after the MFR eruption that was confined by the overlying strong field.Interestingly,a small underlying filament immediately erupted,which was possibly destabilized by the flare ribbon.The successive eruptions were confirmed by the analysis of the emission measure and the reconnection fluxes.Therefore,we suggest that the two peaks of the confined solar flare are corresponding to two episodes of magnetic reconnection during the successive eruptions of the MFR and the underlying filament.

Statistical Study of the Geoeffectivity of Halo Coronal Mass Ejections Associated with X-Class Flares during Solar Cycles 23 and 24

By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 December 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth.

醋酸阿比特龙治疗去势抵抗性前列腺癌早期出现PSA Flare现象的初步分析

目的分析我院泌尿外科治疗中心确诊为去势抵抗型前列腺癌(CRPC)患者、应用醋酸阿比特龙联合泼尼松治疗早期出现PSA Flare现象后对其前列腺特异抗原(PSA)缓解率的影响及部分基线值对PSA Flare出现概率的影响,为后续治疗提供经验。方法本研究共纳入2015年10月至2017年10月接受醋酸阿比特龙联合泼尼松治疗的CRPC患者共计86例,分析其中用药12周以上的55例有效病例的PSA基线值及其变化。结果 55例患者PSA总体缓解为56.4%,其中27.2%(15/55例)的患者出现了PSA Flare现象;PSA再次下降至基线值水平以下的中位时间为3.1(2~6)月。CRPC患者的年龄、PSA基线值、Gleason评分和患者出现PSA Flare现象无明确关联。结论对于醋酸阿比特龙联合泼尼松治疗CRPC患者来说,PSA Flare现象的发生比较常见,和患者年龄、PSA基线值、Gleason评分并无明确关联。在治疗早期药物暴露时间要足够,部分患者可能≥12周,个别患者PSA Flare持续时间达到24周,因此出现PSA Flare并不能说明疾病进展,对疾病进展的预估要结合影像学等多方面证据。

太阳耀斑对无线电导航通信的影响

太阳耀斑是太阳最剧烈的活动,其喷射的X射线和高能粒子可对无线电导航和通信系统产生很大的影响.分析了太阳耀斑爆发后,影响无线电导航通信系统的机理和过程.耀斑可造成无线电导航定位系统的定位精度下降甚至失效、无线电通信噪声和误码率增大甚至通信中断.提出了降低太阳活动对导航和通信影响的一些应对措施.

超声介导瘤内注射99-star治疗肝癌实验病理研究

目的 观察人肝癌 smmc- 772 1裸小鼠模型经中药 99- star治疗的形态学变化。方法 99- star组 11只 ,酒精组 5只 ,生理盐水组 3只 ,分别于背部及肝等移植癌中注射 99- star、酒精和生理盐水等药液。结果 各组移植癌中均出现不同程度坏死 ,以生理盐水组最轻 ;坏死类型 ,注射酒精瘤细胞的蛋白变性呈脱水为特征 ,而 99- star致肿瘤坏死则固缩性和溶解性兼有且发现坏死区间质疏松 ,瘤细胞间距甚宽及有炎症反应。结论 99- star可作为

Optical flare events on the RS Canum Venaticorum star UX Arietis

Based on long-term high-resolution spectroscopic observations obtained during five observing runs from 2001 to 2004, we study optical flare events and chromospheric activity variability of the very active RS CVn star UX Ari. By means of the spectral subtraction technique, several optical chromospheric activity indicators （including the He IDa, Na I D1, D2 doublet, Ha and Ca II IRT lines） covered in our echelle spectra were analyzed. Four large optical flare events were detected on UX Ari during our observations, which show prominent He I D3 line emission together with great enhancement in emission of the Ha and Ca II IRT lines and strong filled-in or emission reversal features in the Na ! D1, D2 doublet lines. The newly detected flares are much more energetic than previous discoveries, especially for the flare identified during the 2002 December observing run. Optical flare events on UX Ari are more likely to be observed around two quadratures of the system, except for our optical flares detected during the 2004 November observing run. Moreover, we have found rotational modulation of chromospheric activity in the Ha and Ca II IRT lines, which suggests the presence of chromospherically active longitudes over the surface of UX Ari. The change in chromospherically active longitudes among our observing runs, as well as the variation in chromospheric activity level from 2001 to 2004, indicates a long-term evolution of active regions.

海洋平台FLARESIM火炬模拟计算方法探讨

FLARESIM软件是一款用于火炬分析与设计的专业软件,它可以分析火炬泄放时产生的热辐射、温度和噪音,同时也可以进行可燃气体的扩散分析。作为火炬模拟与计算的专业软件,FLARESIM越来越多地应用于石油、石化行业。分析了几种常用的计算方法并以某海上平台为例,运用FLARESIM软件进行模拟,着重比较FLaresim API与Mixed方法对模拟结果的影响,研发了一套适用于一般项目的工程模拟方法。

一过性升高(flare-up)在促排卵中的应用

The accurate release of a large amount FSH and LH caused by flare-up can be used not only for controlled ovary hyperstimulation for poor responders,but also for ovulation induction of PCOS patients as well as to prevent multiple follicles development,multiple gestation and ovary hyperstimulation.Details should be paid attention to while adopting the flare-up protocol,in order to take it’s advantages and avoid disadvantages.

超声介导瘤内注射“99-star”治疗人肝癌smmc-7721裸鼠模型中Bcl-2蛋白表达

目的 研究人肝瘤 smmc- 772 1裸小鼠模型经中药“99- star”治疗后 Bcl- 2蛋白表达。方法 于裸小鼠背部和肝等移植癌中 ,1 1只注射“99- star”,5只注射酒精和 3只注射生理盐水 ,动物处死后应用免疫组化方法检测移植癌组织中 Bcl- 2蛋白表达。结果 对照组与各实验组移植癌和移植癌组织与药物注射引起肿瘤坏死的 Bcl- 2蛋白表达 ,在统计学上有显著差别。结论“99- star”可供 B超介导治疗肝癌的有效药物目的 研究人肝瘤 smmc- 772 1裸小鼠模型经中药“99- star”治疗后 Bcl- 2蛋白表达。方法 于裸小鼠背部和肝等移植癌中 ,1 1只注射“99- star”,5只注射酒精和 3只注射生理盐水 ,动物处死后应用免疫组化方法检测移植癌组织中 Bcl- 2蛋白表达。结果 对照组与各实验组移植癌和移植癌组织与药物注射引起肿瘤坏死的 Bcl- 2蛋白表达 ,在统计学上有显著差别。结论“99- star”可供

1980年5月21日—22日耀斑后冕拱(Post-flare coronal arch)的加热机制和稳定性

本文提出了快撕裂模加热是1980年5月21日—22日耀斑后冕拱长达10多小时的有效加热机制。作者计算了撕裂模所提供的能量和相应的增长率,并讨论了该冕拱的MHD平衡和稳定性问题,主要结论如下:1.对5月21日冕拱,当密度取1.6×10~9cm^(-3)(实测值)时,剪切宽度α_α=1.8×10~8cm(冕拱小半径的十分之一)剪切磁场为18—32×10^(-4)T,所对应的增长率为1.79×10^(-5)s^(-1)—2.66×10^(-5)s^(-1),不稳定的增长时间为15.5h—10.4h,这组解与观测到的冕拱存在10多小时相符。所以,撕裂模是冕拱合理的有效加热机制。2.该冕拱之所以维持10多小时之久,除撕裂模加热与辐射损失平衡外,在力学上必须处于平衡态,其平衡条件为B_φ(冕拱轴向磁场)=2B_θ(冕拱的环向场),和气压梯度dp/dr大于零。若冕拱满足该力学平衡条件,则利用能量原理可得到该系统对腊肠扰动、扭曲扰动、螺旋扰动均是稳定的。

活塞环润滑理论的发展及美国FLARE软件包

1 前言 活塞环的润滑状况一直是人们关心的重要课题,因为发动机约60%的摩擦损失消耗在活塞环与缺套的摩擦上。不仅如此,发动机的寿命也是以这对摩擦副的磨损程度为依据的。因此要想提高发动机的工作性能和延长发动机的使用寿命就必须对这对摩擦副的润滑状况进行深入细致的研究。 50年代末期,专家预测活塞环寿命只有2万km。

Hypersonic boundary-layer transition on a flared cone

Transition on a flared cone with zero angle of at- tack was studied in our newly established Mach 6 quiet wind tunnel （M6QT） via wall pressure measurement and flow visualization. High-frequency pressure transducers were used to measure the second-mode waves＇ amplitudes and frequencies. Using pulsed schlieren diagnostic and Rayleigh scattering technique, we got a clear evolution of the second-mode disturbances. The second-mode waves exist for a long distance, which means that the second-mode waves grow linearly in a large region. Strong Mach waves are radiated from the edge of the boundary layer. With further development, the second-mode waves reach their maximum magnitude and harmonics of the second-mode instability appear. Then the disturbances grow nonlinearly. The second modes become weak and merge with each other. Finally, the nonlinear interaction of disturbance leads to a relatively quiet zone, which further breaks down, resulting in the transition of the bound- ary layer. Our results show that transition is determined by the second mode. The quiet zone before the final breakdown is observed in flow visualization for the first time. Eventual transition requires the presence of a quiet zone generated by nonlinear interactions.

Aspen Flare System Analyzer在火炬管网设计与分析中的具体应用

火炬气的排放系统设计是一个非常复杂的过程,涉及到各泄放点的背压与管路马赫数的计算。介绍了Aspen Flare System Analyzer模拟软件的特点及应用方法,该软件遵循API的规范要求,通过计算火炬管网中各管段始末点的压力、温度、流速等参数,可有效发现设计中的不合理管径并进行修改。以中东某油田地面工程项目为例,阐述了在工程实际中如何通过该软件进行火炬管网核算。高压火炬管网的核算结果显示,部分安全阀尾管背压和马赫数过大,经软件修改后的尺寸在实际运行中可满足火炬气的排放要求,保证了系统安全。表明了该软件在安全阀的选型和火炬管网的设计工作中的应用价值。

Effect of restoration technique on resistance to fracture of endodontically treated anterior teeth with flared root canals

This study was designed to compare the impact of post and core systems on resistance to fracture of endodontically treated anterior teeth with flared root canals and to assess their fracture pattern. Sixty central incisors were cut horizontally 2 mm coronal to the cementoenamel junction(CEJ). After root canal therapy, teeth were assigned into 6 groups(n = 10 each) based on a post system and used as follows: Group C, non-flared root received size #1 glass fiber posts(Control); Group AP, flared root restored with anatomical post; Group RC, flared root restored with size #1 fiber post and cemented with thick layer of resin cement; Group CR, flared root restored with size #1 and reinforced with composite resin; Group CM, cast post-core; Group CP, CAD/CAM polymer-infiltrated ceramic post and core.Following post cementation, core build-up and crown insertion, the specimens were thermo-cycled up to 10,000 cycles(5 C/55 C; 30 seconds dwell time, 6 seconds transition time) and then statically loaded at 1 mm/minute crosshead speed using a universal testing machine. One-way ANOVA and Tukey HSD post hoc test(α= 0.05) were used for data analysis. Group C recorded significantly higher resistance to fracture values [(826.9±39.1) N] followed by group CP [(793.8±55.6) N] while group RC yielded the lowest fracture resistance values [(586.7±51.4) N]. The resistance to fracture of wide root canals can be enhanced by using one-piece CAM/CAM post and core as an alternative to the use of either glass fiber post, relined with composite resin increasing the thickness of luting cement or the use of cast post and core system. However, this was an in vitro investigation and further in vivo studies are necessary.

一种基于功能层的Lens Flare处理算法

在摄影领域,镜头眩光是一种很常见的光学现象,在镜头朝向如太阳等强光源进行拍摄时,这种现象尤为明显。本文介绍了一种基于额外层次的镜头光源生成算法。该方法可以较为方便地生成可信度较高的镜头眩光效果,并且支持更多的后期处理。

Support Vector Machine combined with K-Nearest Neighbors for Solar Flare Forecasting

A method combining the support vector machine （SVM） the K-Nearest Neighbors （KNN）, labelled the SVM-KNN method, is used to construct a solar flare forecasting model. Based on a proven relationship between SVM and KNN, the SVM-KNN method improves the SVM algorithm of classification by taking advantage of the KNN algorithm according to the distribution of test samples in a feature space. In our flare forecast study, sunspots and 10cm radio flux data observed during Solar Cycle 23 are taken as predictors, and whether an M class flare will occur for each active region within two days will be predicted. The SVM- KNN method is compared with the SVM and Neural networks-based method. The test results indicate that the rate of correct predictions from the SVM-KNN method is higher than that from the other two methods. This method shows promise as a practicable future forecasting model.