全文获取类型
收费全文 | 62篇 |
免费 | 10篇 |
国内免费 | 2篇 |
专业分类
大气科学 | 10篇 |
地球物理 | 24篇 |
地质学 | 4篇 |
海洋学 | 2篇 |
天文学 | 29篇 |
综合类 | 1篇 |
自然地理 | 4篇 |
出版年
2024年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2015年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有74条查询结果,搜索用时 109 毫秒
71.
本文对8个活动区极性反转线(中性线)附近黑子半影纤维的形态进行了分析得出:1)具有强δ磁结构的活动区,穿过主要异极性黑子间的中性线近旁半影纤维或多或少地与中性线平行(交角小于30°),有关黑子半影呈旋涡形态;2)由新浮现发展形成的δ结构区,异级黑子在大黑子边缘或与大.黑子本影之间有一段距离,中性线两边的半影纤维有序排列,走向与中性线斜交,有关黑子呈弱的旋涡形态。3)对于较稳定的极群,N、S极性间的宽窄不一的半影稀疏区,中性线沿该区经过,两旁半影松散齿状,走向与中性线大体垂直,相反极性本影间距较远。 相似文献
72.
The hemispheric coupling phenomenon of solar activity cycle was discovered as early as the mid-20th century, and it is one of the most common topic in the long-term spatio-temporal evolution of the Sun, while the observational features and physical mechanism of hemispheric coupling have not been completely understood. The theoretical model of solar magnetohydrodynamics driven by this phenomenon is helpful in studying the basic information of the spatio-temporal evolution of solar activity cycle, and is also of great value to the short- and medium-term forecast of solar activity as well as the space weather. Here, we first give the discovery and observational history of the hemispheric coupling of solar activity. And then, the basic observational features of hemispheric coupling at different spatio-temporal scales and their possible mechanism are summarized. Finally, we give a discussion about the important unresolved issues and development trends in this important field. 相似文献
73.
本文利用1949~1997年的资料,以统计分析的方法,对太阳黑子及东海气旋①,热带气旋②活动的互相关系,进行了初步探讨,归纳出几点有参考价值的结论 相似文献
74.
《New Astronomy》2024
A huge collection of solar images to visualize sunspot are acquired by various solar observatories spread across the globe. This necessitates efficient tools for detecting and analyzing the sunspots encompassing diverse solar features. One such contribution is delivered in this work by exploiting the intrinsic intensity variations of solar images associated with sunspots and their attributes. The presented mechanism initially, pre-processes the acquired solar images by correcting the intensity variations introduced while profiling from the sun center to the limb followed by smoothening using a localized window. The resultant is then differenced from the global threshold that is obtained as a result of the statistical analysis computed over the probability distribution function of the input image. This arrangement offers higher discerning variations concerned with the local contextual structures related to sunspot, umbra, and penumbra. Also, it captures the major gradient variation between these regions that adds to the pixel heterogeneity surrounding them to finally render an automatic sunspot detection mechanism distinguishing the diverse solar regions. Receiver Operating Characteristics (ROC) investigation on annual solar images in Flexible Image Transport System (FITS) format reveals the presented method’s efficacy. Also, Pearson correlation analysis of the evaluated sunspot numbers from the detected sunspots with the solar catalog reveals the scheme’s detection closeness. Moreover, the model’s simplicity analyzed along the time and space dimensions affirms its extension to real-time analysis 相似文献