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1.
哈尼族原始的历法,是将一年分成10个月、每个月固定为36天,另外5～6天余日用于过新年,简称十月历。在受到汉族的农历影响、接受了一年分成12个月的概念后,十月历与十二月历被混淆在一起,出现了有月份重叠的现象,即在生活中,注重以十二生肖纪日,以物候指导生产,纪月相当模糊,相差几天也无所谓的局面。 据哈尼族的神话传说和云南绿春县的白氏家谱分析,哈尼族从使用十月历转向接受十二月历的概念,约开始于公元14世纪,而后逐渐扩展开来,十月历渐渐被淡忘。但是,转向完全使用农历,却经历了漫长的历史时期,直至1950年还没有完成这一转变过程,主要原因是经济发展极端缓慢,交通困难,很少与外部进行交流。 相似文献
2.
古代文献记载帝尧时的历法存在两种不同说法。羲和观测四仲中星定季节当是不实之辞,并以闰月成岁推论为使用农历也没依据。羲和观测太阳出没方位变化而"生十日"、即制订产生十月太阳历才符合事实。在文[1]中的推论,也与后一种说法可互相印证。本文对文[1]的推论作出了论据补充,与文[1]成姐妹篇。 相似文献
3.
布朗族使用傣历（祖葛历）,以月份结合物候变化指导生产,生活中使用７ｄ（天）为１轮的纪日制度,并将７个日名赋予不同寓意。这种状况可能距今只有２００余年的历史,在此以前的历法,由于没有文字记录而被完全淡忘了,但从其先民的崖画和口头流传的传说中,有阴阳并重、同时崇拜太阳和月亮的内容看,是处于阴阳合历初期的“物候历”,其内容应与佤族（清朝时分化）的阴阳历相似。 相似文献
4.
云南丰富多彩的少数民族传统文化，在天文方面呈现为“物候历”、太阳历和阴阳合历等等，曾在历史上长期并存使用，与各个民族的社会经济发展相适应。这种现象与民族的迁徙紧密联系，早期的越人和羌人迁徙云南，可追溯到战国时期，甚至是新石器时期。大规模的迁徙意味着文化的迁徙，迁徙可促进文化的发展，也可使文化倒退，重要的原因之一，是能否与外界进行交流，吸取先进的成分来发展自己。认同他人的某些传统内容，也会形成地域性的共同文化现象，除历法外，鼓文化也是典型例子。 相似文献
5.
Distribution, over the lunar age, of the frequency of occurrence of the afternoon counter-electrojet events at Trivandrum during the period 1959–1978 is examined in each of the calendar months. A strong lunar modulation on the occurrence frequency is seen in January; this may be related to the global enhancement of the lunar tide during January. The modulation is also prominent in April, although 62% of the events in that month occur irrespective of the lunar age. The occurrence frequency at Trivandrum appears to be least influenced by the Moon in the northern summer months. 相似文献
6.
元代郭守敬等1280年编制的《授时历》是中国本土科学家研制的最后一部历法,具有极高的精度。采用其仍可预报2012年5月21日发生的日食,其预报北京地区的见食情况时食甚时刻误差4 min,食分误差为0.04。给出了《授时历》推步的1990～2050年北京的见食情况及精度,其中食甚时刻的标准偏差为103.04 min,食分的标准偏差则不低于0.33。通过考察1280～2050年间186个日食计算结果,可得出《授时历》自行用以来推步日食的误差,考虑到存在错报(不可见)和漏报因素的影响,其食甚时刻和食分的标准偏差分别不低于50.65 min和0.19;同时指出,随着行用时间的延长其推时误差也逐步放大。 相似文献
7.
夏商周断代工程及其天文学问题 总被引：1，自引：0，他引：1
《夏商周断代工程》由文献,考古,古文字,碳14测年和天文学待方面的专家联合攻关,致车于推进我国早期年代学研究的发展,天文学在五星聚合,三代大火,国外天象,仲康日食,夏小正,禹伐三苗,甲骨文天象,武王伐纣,天再旦,金文历谱,周代历法,计算中心等专题中起了主要或重要作用,天文方法确定的宾组月食,武王伐纣和天再旦年代被作为断代工程结论而采用,成为夏商周年的重要支撑点,铜器铭文中的朋相记录也是西周列王年代的重要依据。 相似文献
8.
“干支回推法”是针对中国历史时期所特有的干支材料而设计的新天文年代学方法．以一组假设的材料为例,系统地给出了该方法的完整求解过程．指出该方法的优势在于准确高效,能有效地处理某些年代学难题．此外,除材料的公历日期外还能将当时的历法细节一同迭代解出． 相似文献
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中国古历经朔数据的恢复及应用 总被引：3，自引：0，他引：3
中国元代的《授时历议》保存了44部古历的推朔参数及比验资料．借助古代朔望计算方法：1）恢复了诸历行用初年的天正经朔数值；2）修正了史载的错误数据．3）根据Meeus方法计算出经朔的理论值，并由此确定古历经朔的推步精度；4）尝试应用这些数据考察地球自转长期变化，得出日长变化为1．8ms／cy． 相似文献
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13.
Sh. T. Habibullin 《Earth, Moon, and Planets》1971,3(2):231-238
Attention is drawn to the absence in literature of the precise definitions of selenographic and celestial selenocentric coordinate systems. In certain cases inaccuracies in the formulation of the first Cassini law occur. This is due to the fact that the principal directions dealt with in the theory of lunar rotation are being constantly confused. A clear-cut definition of the principal coordinate systems concerned with the lunar rotation is given. It is indicated that there is no necessity in a special astronomical time service on the Moon. Since the future expeditions to the Moon will be able to keep terrestrial time, the problem of the hour angle is simply solved by the Formula (11). 相似文献
14.
Mineral mapping of the lunar surface is critical to understanding the Moon’s geological diversity and history, yet the global lunar abundance of minerals has not been mapped using hyperspectral data. The Interference Imaging Spectrometer (IIM) of Chang’E-1 mission obtained hyperspectral data of the global lunar surface within the wavelength of 480–960 nm in which major minerals can be discriminated by faint differences in 32 contiguous hyperspectral bands. The effect of space weathering produces multiple endmembers of lunar minerals by obscuring the pure spectra of minerals in different levels. In this study, the distributions of plagioclase, clinopyroxene and olivine on the global lunar surface were mapped with IIM hyperspectral data based on the modified Multiple Endmember Spectral Mixture Analysis (MESMA) method considering the space weathering effect. The distribution of lunar space weathering levels was retrieved as a byproduct of mineral mapping. The mineral mapping results were compared with recent mapping results. Although the wavelength of IIM is limited, it shows that our results are basically consistent with the recent research at both global and local scales. The distribution of space weathering levels is also consistent with the map of optical maturity parameter (OMAT) in most parts of the global lunar surface, especially in the highlands. This study demonstrates that the modified MESMA method is an effective approach to quantitative mapping of the lunar minerals and space weathering levels using hyperspectral data. In the future, more minerals can be mapped with higher accuracy if hyperspectral data with a wider spectral range are used based on the method proposed in this study. 相似文献
15.
The Shoushi calendar (epoch of AD 1281, Yuan dynasty) is famous and very accurate in ancient China. It has evolved perfect and complete theoretical models of solar system
objects, such as solar and lunar motions during that period. Almost every part of this work corresponds to the modern astronomical
yearbooks. Compiled by native Chinese astronomers, it sums up through their studies many real observing results. The mathematical
methods were adopted in this calendar before the foundation of Newton’s mechanical system. It is presented in this paper that
the indirect system is also very useful to recover the real observing historical material. By selecting these calculating
results, we may sum up the integral data of the secular variation of the Earth’s rotation from 1000 BC to AD 1500.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
用天文方法建立商后期甲骨文年代序列的新途径—解析殷历月法 总被引：8，自引：2，他引：6
利用对具有月龄特征的历谱规律的研究成果，以推定甲骨文的绝对年代，从而提供了建立商后期甲骨文年代序列的新方法，并给出了13版卜辞的例证，通过分析殷历月的结构，得出殷历中“二癸月”和“四癸月”的月首分别为首甲日和首癸日，初步归纳出殷历月法，月首为初三，月长等于逆望月周期，建立固定，且找到建立丑之例，置闰规律未知，已存在年终，年中置闰两种闰法。 相似文献
17.
Asymmetry, a well established fact, can be extracted from various solar atmospheric activity indices. Although asymmetry is being localized within short time scale, it also persists at different time scales. In the present study we examine the character and nature of asymmetry at various time scales by optimizing the data set, in units of Carrington Rotations (CRs), for Sunspot Area (SA) and soft X-ray flare index (FI SXR). We find from three solar cycles (21-23) that at a small time scale (viz., daily, CRs and monthly) activity appears to be asymmetric with less significance. At larger time scales (≥01 CRs) strength of asymmetry enhances. Number of significant asymmetry points probably depends upon the solar heights. For different combination of data, asymmetry strength appears to be lowered at certain periods ～06, ～12, ～18 CRs (164, 327 and 492 days i.e., harmonics of ～1.3 years. Owing to similar behavior of emergence of magnetic flux, it is conjectured that emergence of flux on the surface probably contributes to the asymmetry of the solar activity. 相似文献
18.
We introduce on/off intermittency into a mean field dynamo model by imposing stochastic fluctuations in either the alpha effect or through the inclusion of a fluctuating electromotive force. Sufficiently strong small scale fluctuations with time scales of the order of 0.3–3 years can produce long term variations in the system on time scales of the order of hundreds of years. However, global suppression of magnetic activity in both hemispheres at once was not observed. The variation of the magnetic field does not resemble that of the sunspot number, but is more reminiscent of the 10Be record. The interpretation of our results focuses attention on the connection between the level of magnetic activity and the sunspot number, an issue that must be elucidated if long term solar effects are to be well understood. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
19.
In situ measurements at the lunar surface at millimeter resolution by the Apollo astronauts have been analyzed. Several statistical parameters have been determined for the landing site. The surface roughness has been found to be very nearly gaussian. The root-mean-square slopes have been obtained over scales between 0.5 mm and 5 cm. They steadily decrease with increasing scale length from 58° to 2° and are in reasonable agreement with radar-measured values. The autocorrelation coefficient of the height distribution has also been obtained. It has a scale-length of 0.7 mm.Adjunct Professor at the University of Massachusetts.Visiting Scholar at the University of Massachusetts. 相似文献
20.
Adrian Liu Max Tegmark Judd Bowman † Jacqueline Hewitt Matias Zaldarriaga 《Monthly notices of the Royal Astronomical Society》2009,398(1):401-406
21-cm tomography is expected to be difficult in part because of serious foreground contamination. Previous studies have found that line-of-sight approaches are capable of cleaning foregrounds to an acceptable level on large spatial scales, but not on small spatial scales. In this paper, we introduce a Fourier space formalism for describing the line-of-sight methods, and use it to introduce an improved new method for 21-cm foreground cleaning. Heuristically, this method involves fitting foregrounds in Fourier space using weighted polynomial fits, with each pixel weighted according to its information content. We show that the new method reproduces the old one on large angular scales, and gives marked improvements on small scales at essentially no extra computational cost. 相似文献