Chinese AstronomyPub Date : 1980-03-01DOI: 10.1016/0146-6364(80)90063-8
Zhang He-qi
{"title":"A possible mechanism for producing cosmic gamma ray bursts","authors":"Zhang He-qi","doi":"10.1016/0146-6364(80)90063-8","DOIUrl":"10.1016/0146-6364(80)90063-8","url":null,"abstract":"<div><p>In this paper, we propose a model to explain the energy supply of cosmic γ-ray bursts by means of magnetic energy annihilation in neutral sheets formed in local active regions on magnetic white dwarfs. According to this model the instability process in the plasma consists of two phases, a thermal explosive phase and a steady annihilation phase. The magnetic energy stored in the local source is efficiently converted into kinetic energy and the energy dissipation is at a rate consistent with the observations. With the rapid increase of anomalous resistivity a plasma turbulence field is set up which can immediately be coupled with fast electrons in the Maxwellian high energy tail. The relativistic electrons are then produced within a time as short as 10<sup>−8</sup> sec., which is not in conflict with the fast ascent of brief “spikes” of gamma rays. The calculated results indicate that the γ-rays can also be emitted through synchrotron radiation by the accelerated electrons moving around the magnetic field.</p><p>While many details of this theoretical model remain to be cleared up, the present point of view may be taken as a promising basis for future work.</p></div>","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"4 1","pages":"Pages 74-83"},"PeriodicalIF":0.0,"publicationDate":"1980-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0146-6364(80)90063-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72848207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1980-03-01DOI: 10.1016/0146-6364(80)90064-X
Su Ding-qian, Wang Ya-nan, Zhou Bi-fang, Lu Sheng-dong
{"title":"An algorithm for finding the extreme values of a function of many variables and its application in the automatic design of astronomical optical systems","authors":"Su Ding-qian, Wang Ya-nan, Zhou Bi-fang, Lu Sheng-dong","doi":"10.1016/0146-6364(80)90064-X","DOIUrl":"10.1016/0146-6364(80)90064-X","url":null,"abstract":"<div><p>It is shown that if the equipotentials are <em>n</em>-dimensional ellipsoids, then the streamlines will converge to the centre of the ellipsoids representing minimum potential, and in doing so, the streamlines will get closer and closer to the longest axist of the ellipsoids.</p><p>Based on the above consideration, an algorithm is presented for finding the minimum point of the function <em>φ</em> = <em>Σf</em><sub><em>i</em></sub><sup>2</sup>. At each iteration, we take the linear expansions of <em>f</em><sub><em>i</em></sub> and proceed along the streamlines corresponding to the resulting, approximate φ, of which the equipotentials are ellipsoids. When we are close to the longest axis of the ellipsoids, we take a suitable leap along the line joining the current point to the centre of the ellipsoid, to begin the next iteration. This method has been found effective in the automatic design of astronomical optical systems. Three examples are given.</p></div>","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"4 1","pages":"Pages 84-89"},"PeriodicalIF":0.0,"publicationDate":"1980-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0146-6364(80)90064-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81078209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1980-03-01DOI: 10.1016/0146-6364(80)90055-9
Polar Motion Collaboration Group
{"title":"Motion of the pole in the years 1949 – 1976","authors":"Polar Motion Collaboration Group","doi":"10.1016/0146-6364(80)90055-9","DOIUrl":"https://doi.org/10.1016/0146-6364(80)90055-9","url":null,"abstract":"<div><p>Based on data of latitude observations from 41 stations and observatories, the secular and periodic components of the polar motion were separately derived. A system of coordinates of the pole, with origin at the mean pole of 1968.0, called JYD, was set up and the coordinates for the year 1949.0 – 1976.0 are given.</p></div>","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"4 1","pages":"Pages 1-8"},"PeriodicalIF":0.0,"publicationDate":"1980-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0146-6364(80)90055-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136705954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1979-12-01DOI: 10.1016/0146-6364(79)90031-8
Wu Lian-da
{"title":"On the additional perturbations in the theory of motion of artificial satellites","authors":"Wu Lian-da","doi":"10.1016/0146-6364(79)90031-8","DOIUrl":"https://doi.org/10.1016/0146-6364(79)90031-8","url":null,"abstract":"","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"179 1","pages":"409-415"},"PeriodicalIF":0.0,"publicationDate":"1979-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72710950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1979-12-01DOI: 10.1016/0146-6364(79)90030-6
Zhang Bo-rong, Zhong Shu-hua, Wang Hong-zhao
{"title":"Accelerated rotation of the sunspots of September 1977 and the spiral structure in their penumbrae","authors":"Zhang Bo-rong, Zhong Shu-hua, Wang Hong-zhao","doi":"10.1016/0146-6364(79)90030-6","DOIUrl":"https://doi.org/10.1016/0146-6364(79)90030-6","url":null,"abstract":"","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"3 4","pages":"Pages 400-408"},"PeriodicalIF":0.0,"publicationDate":"1979-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0146-6364(79)90030-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91763384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1979-12-01DOI: 10.1016/0146-6364(79)90026-4
Luo Ding-jiang, Zhu Yuan-xian, Xiao Nai-yuan, Miao Yong-kuan, Lin Zhao-fen
{"title":"The astrolabe catalogue (ACPI) of the Peking astronomical observatory","authors":"Luo Ding-jiang, Zhu Yuan-xian, Xiao Nai-yuan, Miao Yong-kuan, Lin Zhao-fen","doi":"10.1016/0146-6364(79)90026-4","DOIUrl":"https://doi.org/10.1016/0146-6364(79)90026-4","url":null,"abstract":"<div><p>Using the results of our latitude and time programs obtained with the impersonal astrolabe (OPL No. 30) of the Peking Observatory, we have calculated the corrections to individual star positions and the systematic corrections Δα<sub>δ</sub> and Δδ<sub>δ</sub> to catalogue positions.</p></div>","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"3 4","pages":"Pages 349-371"},"PeriodicalIF":0.0,"publicationDate":"1979-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0146-6364(79)90026-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91763390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1979-12-01DOI: 10.1016/0146-6364(79)90028-8
Zhou You-yuan, Fang Li-zhi, Cheng Fu-hua, C. Fu-zhen
{"title":"Statistical analyses of quasars with resolved radio components. III. Evolutionary properties of the sizes of components. IV. Evolutionary properties of radio polarization parameters","authors":"Zhou You-yuan, Fang Li-zhi, Cheng Fu-hua, C. Fu-zhen","doi":"10.1016/0146-6364(79)90028-8","DOIUrl":"https://doi.org/10.1016/0146-6364(79)90028-8","url":null,"abstract":"","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"24 1","pages":"380-393"},"PeriodicalIF":0.0,"publicationDate":"1979-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74724154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chinese AstronomyPub Date : 1979-12-01DOI: 10.1016/0146-6364(79)90024-0
Kun-yi Huang, Xiong Zhou
{"title":"A method of finding the longitude and latitude of a ground station using simultaneous photographic observations of satellites","authors":"Kun-yi Huang, Xiong Zhou","doi":"10.1016/0146-6364(79)90024-0","DOIUrl":"https://doi.org/10.1016/0146-6364(79)90024-0","url":null,"abstract":"","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"9 1","pages":"323-331"},"PeriodicalIF":0.0,"publicationDate":"1979-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89021512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}