干支回推-天文年代学的一种新方法

“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．

Recover Dates from Historical Ganzhi Records: A New Method of Chinese Astronomical Chronology

As a puzzle how to recover the dates particularly from the original historical Ganzhi (the Heavenly Stems and Earthly Branches) style to their belongings in Julian or Gregorian calendar system has been encountered in China for many years, for example, we are even unclear when the famous Xia, Shang and Zhou dynasties began and how many years the different kings occupied their powers for. After 1996, the Xia - Shang - Zhou Chronology Project was operated in order to do this work and then we have designed two new astronomical chronology methods, both named the Moon Age Method and Direct Solving Method, and here we give their detailed process. First we select eight dates at random from modern calendar from 1945 to 2005, and then change them to two types of historical Ganzhi style with 60-day cycle. These known dates, which simulate Chinese ancient dates but have incomplete parameters, are defined and provided for new astronomical chronology methods to investigate whether the real dates can be obtained again. Type A date knows the lunar month, day (moon age) and Ganzhi . Type B only knows the year, lunar month and Ganzhi. Then according to the traditional astronomical method, the total possible new moon dates which related to the eight dates of Type A and Type B are given respectively. But how to find the best results from a large number of candidates derived from traditional methods has become the key point and profound of the new methods. Afterwards, we employ both new methods step by step, the results of Type A data may be derived by the Moon Age Method and half obtain the unique solution, at the same time screen efficiency improves about 8 times. And the results of Type B data can also be obtained by the Direct Solving Method and each of them is just the same as what we set before, screen efficiency improves more than 18 times. In fact, both new methods have deepened the traditional methods. It is their superiority that some of the chronology problems can be investigated accurately and effectively. Otherwise, not only the dates can be obtained and converted to Julian or Gregorian calendar system but some of the import parameters of ancient calendar issued then can also be revealed.