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Total Electron Content Diurnal and Seasonal Variations and Response to Solar Events at Koudougou Station in Burkina Faso
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作者 Yacouba Sawadogo M’Bi Kaboré +2 位作者 Somaïla Koala Arouna Mandé Jean Louis Zerbo 《International Journal of Geosciences》 2023年第9期827-839,共13页
In this paper, we studied the seasonal behavior of the total electron content (TEC) during a part of solar cycle 24 ascending, maximum and decreasing phases at Koudougou station (Latitude: 12°15'09"N Lon... In this paper, we studied the seasonal behavior of the total electron content (TEC) during a part of solar cycle 24 ascending, maximum and decreasing phases at Koudougou station (Latitude: 12°15'09"N Longitude: 2°21'45"W). Response of TEC to solar recurrent events is presented. The highest values of the TEC in 2014, 2015 and 2016 were recorded on March and October, while in 2013 they were recorded on April and November, corresponding to equinox months. This observation shows that TEC values at the equinoxes are higher than those of solstices. Moreover, the monthly TEC varies in phase with the sunspots number showing a linear dependence of the TEC on solar activity. The ionospheric electron contents are generally very low both before noon and during the night, but quite high at noon and after noon. This pattern of TEC variation is due to the fluctuation of incident solar radiation on the Earth’s equatorial ionosphere. During quiet periods, the number of free electrons generated is lower than that generated during recurrent periods, which shows a positive contribution of recurrent activity to the level of the TEC. Investigations have also highlighted a winter anomaly and equinoctial asymmetry in TEC behavior at Koudougou station. 展开更多
关键词 Total Electron Content (TEC) Recurrent activity quiet activity Seasonal Variation
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2014年云南景谷6.6级地震前地震活动异常特征研究 被引量:2
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作者 邓嘉美 高琼 +2 位作者 陈佳 张华英 王军 《地震地磁观测与研究》 2016年第2期15-20,共6页
2014年10月7日云南景谷发生6.6级地震,此次地震前,滇西南地区存在长达7.3年的6级地震平静异常和2536天5级地震平静异常。与5级地震、6级地震平静不同的是,思普地区4级地震异常活跃。景谷地震发生在由4级地震形成的背景空区、3级地震形... 2014年10月7日云南景谷发生6.6级地震,此次地震前,滇西南地区存在长达7.3年的6级地震平静异常和2536天5级地震平静异常。与5级地震、6级地震平静不同的是,思普地区4级地震异常活跃。景谷地震发生在由4级地震形成的背景空区、3级地震形成的孕震空区内。2014年10月7日5时36分发生的3.5级地震打破3级地震围空,属于逼近地震。研究表明,景谷地震前的地震活动呈现长期、中期、短临特征。 展开更多
关键词 景谷地震 地震平静 活跃 围空
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Circadian Rhythms of Physiological Functions of the Pregnant Woman and the Fetus and the Biological Solemnity Thereof
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作者 Medea G. Zarnadze 《Open Journal of Obstetrics and Gynecology》 2016年第8期482-514,共34页
The basic rhythms of nature that left their imprint on the existence of all living organism on the Earth, arose under the influence of the Earth’s rotation relative to the Sun, the Moon and other planets and stars of... The basic rhythms of nature that left their imprint on the existence of all living organism on the Earth, arose under the influence of the Earth’s rotation relative to the Sun, the Moon and other planets and stars of the Universe. This periodicity gave rise to the rhythm that has become essential for their life. Life is a continual chemical process of building up and breaking down of organic substances, which results from the substance exchange between an organism and the environment. This makes it impossible for a living organism to exist without the external environment. Since 1978-1979 we have been carrying out a task-oriented research with the aim to approximate the moment when we are able to answer all these questions. Daily fluctuations of cardiac and motor activity of the fetus have been studied (uninterrupted daily recording of fetal ECG);polysomnography of nocturnal sleep was recorded;daily fluctuations of endocrine system activity in the pregnant were studied. A correlation was made between the functional state of maternal sleep-wakefulness biological rhythm, biological clock of the human fetus and the “light-darkness” cycle of a 24-hour solar day. In the process of the study we have developed an original method of day-to-day analysis of maternal and fetal ECGs. It has been established that a healthy fetus has distinct, diurnal variations of physiological functions. The fetal biorhythms coordinate with the status of the maternal organism being, however, in an opposite phase. The curve of the dynamics of fetal physiological system functioning shows a biphasic nature (one-phase in adults). “Active” and “quiet” (sleep-like) periods have been singled out in the human fetus. No reaction is observed in “quiet” periods. However, the “zero”-type fetal reaction recorded by us within the period from 2 p.m. to 9 p.m. does not indicate unsatisfactory condition of the fetus but rather is suggestive of a definite reduction of functional levels of the fetal physiological systems, which is necessa 展开更多
关键词 Circadian Rhythms BIORHYTHMS Pregnant Woman Human Fetus Puls Beats Per Minute Cardio Tachogram Abdominal Electrocardiogram Lokomotor activity Test “Activ” quiet Stars Universe Space
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地磁活动K指数值量算和确定方法的改进 被引量:12
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作者 徐文耀 《西北地震学报》 CSCD 北大核心 2005年第z1期36-41,共6页
根据北京十三陵地磁台2001年全年的地磁分钟值,用自然正交分量法(NOC)分析了Sq的逐日变化特性。结果表明,Sq的逐日变化与其日变幅度有相同的量级。由于逐日变化后得到的K指数与常规K指数相比,相差1的情况达到25.4%,相差2的情况达到1.6%... 根据北京十三陵地磁台2001年全年的地磁分钟值,用自然正交分量法(NOC)分析了Sq的逐日变化特性。结果表明,Sq的逐日变化与其日变幅度有相同的量级。由于逐日变化后得到的K指数与常规K指数相比,相差1的情况达到25.4%,相差2的情况达到1.6%,最大相差可以达到3。所以,在量算地磁活动指数时考虑逐日变化是必要的。 展开更多
关键词 地磁场 平静太阳日变化Sq Sq的逐日变化 地磁活动指数
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Total Electron Content during Recurrent and Quiet Geomagnetic Periods at the Koudougou Station in Burkina Faso
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作者 Saguedo Sawadogo Doua Allain Gnabahou +1 位作者 Tinlé Pahima Frédéric Ouattara 《International Journal of Astronomy and Astrophysics》 2023年第3期259-280,共22页
In this work, the comparative study of total electron content (TEC) between recurrent and quiet geomagnetic periods of solar cycle 24 at Koudougou station with geographical coordinates 12°15'N;- 2°20'... In this work, the comparative study of total electron content (TEC) between recurrent and quiet geomagnetic periods of solar cycle 24 at Koudougou station with geographical coordinates 12°15'N;- 2°20'E was addressed. This study aims to analyze how geomagnetic variations influence the behavior of TEC in this specific region. The geomagnetic indices Kp and Dst were used to select quiet and recurrent days. Statistical analysis was used to interpret the graphs. The results show that the mean diurnal TEC has a minimum before dawn (around 0500 UT) and reaches a maximum value around 1400 UT, progressively decreasing after sunset. In comparison, the average diurnal TEC on recurrent days is slightly higher than on quiet days, with an average difference of 7 TECU. This difference increases with the level of geomagnetic disturbance, reaching 21 TECU during a moderate storm. The study also reveals significant monthly variations, with March and October showing the highest TEC values for quiet and recurrent days, respectively. Equinox months show the highest mean values, while solstice months show the lowest. Signatures of semi-annual, winter and equatorial ionization anomalies were observed. When analyzing annual variations, it was found that the TEC variation depends significantly on F10.7 solar flux, explaining up to 98% during recurrent geomagnetic activity and 92% during quiet geomagnetic activity. 展开更多
关键词 Total Electronic Content Geomagnetic activity quiet-Day activity Recurrent-Day activity Solar Flu
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华北第5活动幕平静时段背景下平静异常综合判定 被引量:4
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作者 王想 王亚茹 +2 位作者 宫猛 郭蕾 王晓山 《地震地磁观测与研究》 2017年第1期21-27,共7页
地震平静是国内外普遍认可的具有明确物理意义的地震前兆现象之一,该现象的定义和异常判定以及预报效能多是在地震活动幕活动时段背景下提出的。本文对华北孕震背景进行研究,并在平静时段背景下,以河北地区M 3地震平静8个月,M_L 3地震平... 地震平静是国内外普遍认可的具有明确物理意义的地震前兆现象之一,该现象的定义和异常判定以及预报效能多是在地震活动幕活动时段背景下提出的。本文对华北孕震背景进行研究,并在平静时段背景下,以河北地区M 3地震平静8个月,M_L 3地震平静4个月为配套平静异常指标,概率增益检验显示,该指标具有一定前兆意义。 展开更多
关键词 配套指标 第5活动幕平静时段 综合判定 平静异常 间歇平静
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