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排序方式: 共有21条查询结果,搜索用时 15 毫秒
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A method is described for reconstructing the true geometry of a solar loop observed on the disk which takes account of tilt in its own plane. Reconstructions of three H loops yield small tilt angles (14°) and provide further evidence that H loops show a close correspondence to the field lines of a magnetic dipole. The method offers new opportunities for exploring the physics of individual solar loops.  相似文献   
3.
Excepting intermittent type III activity, all the radio events over the frequency range 8–8000 MHz accompanying the initial stage of the 3B flare of 13 May, 1981 had their onset in a 2-min interval immediately preceding the peak of an impulsive Hα brightening (kernel) well away from the main flare. This kernel is identified as one footpoint of a loop of magnetic flux whose other end terminated in a transient brightening in an adjacent active region.  相似文献   
4.
Reviews of long-term predictions of solar cycles have shown that a precise prediction with a lead time of 2 years or more of a solar cycle remains an unsolved problem. We used a simple method, the method of similar cycles, to make long-term predictions of not only the maximum amplitude but also the smoothed monthly mean sunspot number for every month of Solar Cycle 23. We verify and compare our prediction with the latest available observational results.  相似文献   
5.
微动探测技术被广泛应用于构造、孤石、溶洞等勘查,但是,以常规圆形、嵌套三角形台阵等为代表的测量方式在城区施工会受到现场条件限制,难以实现长剖面数据的高效、高密度采集。针对这一问题,提出一种基于线形台阵多次覆盖的高效数据采集技术,该技术借鉴地震勘探多次覆盖观测系统的思想,布设一次线形台阵可以同时得到多个测点数据,可大大提高单台站数据的利用率。为了研究该采集技术的可行性和有效性,开展了单点频散曲线对比实验和横波速度剖面对比实验,并将其应用于福州城区岩性地层探测实验。实验结果表明:该技术极大地提升了微动数据采集的效率和测量密度,有效改善了探测精度和探测深度,为城市复杂地面环境下开展岩性地层精细划分提供了一种新的台阵布设方案。  相似文献   
6.
本研究克隆得到了一个大竹蛏(Solen grandis)翻译控制肿瘤蛋白(TCTP)基因(SgTCTP)的cDNA全长,其序列全长为1055bp,5′和3′端的非编码区(UTR)分别为54和461bp,开放阅读框(ORF)540bp,编码179个氨基酸,理论等电点为4.50,预测分子量大小19.96kDa。通过荧光定量PCR法检测了SgTCTP在健康大竹蛏各组织中和病原相关分子模式(PAMPs)刺激后的表达规律,结果表明:SgTCTP在检测组织外套膜、鳃、性腺、血细胞、肌肉和肝胰腺中都有表达,其中在肝胰腺中的表达量最高。脂多糖(LPS)、肽聚糖(PGN)和葡聚糖(β-1,3-glucan)刺激都能诱导SgTCTP的表达量上调,SgTCTP的表达量分别在LPS和PGN刺激后6和3h达到最高,为空白对照的3.64和3.36倍;β-1,3-glucan刺激后SgTCTP的表达量上升幅度最大,在12h达到最高,为空白对照的11.76倍。SgTCTP可能作为急性时相蛋白参与大竹蛏的免疫应答。  相似文献   
7.
太阳黑子相对数最强周期的小波分析   总被引:10,自引:0,他引:10       下载免费PDF全文
利用小波变换,分析了1749年以来每个太阳活动周太阳黑子相对数的最强周期以及第1~22太阳活动周的最强周期. 分析结果表明,在第5和第6个太阳活动周,太阳黑子相对数最强的周期分别为64.67年和69.31年;在第13~15太阳活动周,太阳黑子相对数的最强周期分别为98.02年,105.06年和105.06年. 在第1~22太阳活动周中,太阳黑子相对数最强的周期是128个月,约10.67年,其他太阳活动周的最强周期介于9.29~11.43年之间. 本文最后给出了128个月周期的幅度随时间的变化.  相似文献   
8.
We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the amplitudes of the three periods is studied. The results show that around 1750 and 1800, the amplitude of the 53-yr period was much higher than that of the the 11-yr period, that the ca. 53-yr period was apparent only for the interval from 1725 to 1850, and was very low after 1850, that around 1750, 1800 and 1900, the amplitude of the 101-yr period was higher than that of the 11-yr period and that, from 1940 to 2000, the 11-yr period greatly dominates over the other two periods.  相似文献   
9.
Taking the 13-point smoothed monthly sunspot number, Ri, and the deviation of the 13 associated monthly sunspot numbers from the smoothed one, D_i, as a number-pair describing the global level of sunspot activity, the evolution of the level is statistically studied for the period from the month which is just 48 months before the minimum to the minimum in the descending phase, using the observed data of Solar Cycles 10 to 22. Our results show (1) for 46 months (94%) of the studied 49 months it is found that for a given month, the distribution of the 13 pairs which come from the 13 solar cycles on a log Ri-D_i plane may be fitted by a straight line with a correlation coefficient larger than the critical one at confidence level α= 5%, and for 36 months (73%) the fitting is even better, for α= 1%;(2) time variations of these two parameters and their correlations in the studied period can be described respectively by functions of time, whose main trends may be expressed by a linear or simple curvilinear function; (3) the evolutionary path of the level of sunspot activity may be represented by a logarithmic function as log R_i=0.704 In D_i-0.291.  相似文献   
10.
We present a verification of the short-term predictions of solar Xray bursts for the maximum phase (2000-2001) of Solar Cycle 23, issued by two prediction centers. The results are that the rate of correct predictions is about equal for RWC-China and WWA; the rate of too high predictions is greater for RWC-China than for WWA, while the rate of too low predictions is smaller for RWC-China than for WWA.  相似文献   
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