• 제목/요약/키워드: Chinese Astronomy

검색결과 103건 처리시간 0.023초

GPS QUASARS AS SPECIAL BLAZARS

  • BAI J. M.;LEE MYUNG GYONG
    • 천문학회지
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    • 제38권2호
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    • pp.125-128
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    • 2005
  • In this paper, we argue that the gigahertz peaked spectrum (GPS) quasars are special blazars, blazars in dense and dusty gas enviornment. The ROSAT detection rate of GPS quasars is similar to that of flat spectrum radio quasars (FSRQs), suggesting that the relativistic jets in GPS quasars are oriented at small angle to the line of sight. Due to strong inverse Compton scattering off infrared photons from dense and dusty nuclear interstellar media in GPS quasars, most of them may have significant soft gamma-ray and X-ray emission, which is consistent with ASCA X-ray observations. Because Compton cooling in GPS quasars is stronger than that in FSRQs, synchrotron emission in GPS quasars may less dominate over thermal emission of the accretion disk and hot dust, hence most GPS quasars show low optical polarization and small variability, consistent with observations. We suggest that it is the significant radio emission of electron/positron pairs produced by the interaction of gamma-rays with the dense gas and dust grains in GPS quasars that makes GPS quasars show steep radio spectra, low radio polarization, and relatively faint VLBI/VLBA cores. Whether GPS quasars are special blazars can be tested by gamma-ray observations with GLAST in the near future, with the detection rate of GPS quasars being similar to that of FSRQs.

해도산경(海島算經)과 조선(朝鮮) 산학(算學) (Haidao Suanjing in Joseon Mathematics)

  • 홍성사;홍영희;김창일
    • 한국수학사학회지
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    • 제32권6호
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    • pp.259-270
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    • 2019
  • Haidao Suanjing was introduced into Joseon by discussion in Yang Hui Suanfa (楊輝算法) which was brought into Joseon in the 15th century. As is well known, the basic mathematical structure of Haidao Suanjing is perfectly illustrated in Yang Hui Suanfa. Since the 17th century, Chinese mathematicians understood the haidao problem by the Western mathematics, namely an application of similar triangles. The purpose of our paper is to investigate the history of the haidao problem in the Joseon Dynasty. The Joseon mathematicians mainly conformed to Yang Hui's verifications. As a result of the influx of the Western mathematics of the Qing dynasty for the study of astronomy in the 18th century Joseon, Joseon mathematicians also accepted the Western approach to the problem along with Yang Hui Suanfa.

MOLECULAR CLOUD ASSOCIATED WITH AFGL 2591

  • Minh, Y.C.;Yang, Ji
    • 천문학회지
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    • 제41권5호
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    • pp.139-145
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    • 2008
  • The molecular cloud, embedding AFGL 2591, has a "head-and-tail" structure with a total mass of ${\sim}\;1800\;M_{\odot}$, about half of the mass (${\sim}\;900\;M_{\odot}$) in the head (size ${\sim}\;1.2\;pc$ in diameter), and another half in the envelope (${\sim}\;3.5\;pc$ in the east-west direction). We found a new cloud in the direction toward north-east from AFGL 2591 (projected distance ${\sim}\;2.4\;pc$), which is probably associated with the AFGL 2591 cloud. The $^{12}CO$ spectrum clearly shows a blue-shifted high-velocity wing at around the velocity $-20\;{\sim}\;-10\;km\;s^{-1}$, but it is not clear whether this high-velocity component has a bipolar nature in our observations. The observed CN spectra also show blue-shifted wing component but the existence of the red-shifted component is not clear, either. In some CN and HCN spectra, the highvelocity components appear as a different velocity component, not a broad line-wing component. The dense cores, traced by CN and HCN, exist in the 'head' of the AFGL 2591 cloud with an elongated morphology roughly in the north-south direction with a size of about 0.5 pc. The abundance ratio between CN and HCN is found to be about 2 - 3 within the observed region, which may suggest a possibility that this core is being affected by the embedded YSOs or by possible shocks from outside.

1792년에 출간된 새로운 보천가(步天歌)에 대한 연구 (A Study on New Pochonka Published in A.D. 1792)

  • 안상현
    • Journal of Astronomy and Space Sciences
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    • 제26권4호
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    • pp.603-620
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    • 2009
  • 1792년 조선에서 출간된 새로운 보천가(步天歌)는 기존 보천가(步天歌)의 가결(歌訣)을 약간 수정하고 여기에 중국의 새로운 항성 관측 자료를 바탕으로 성립된 성도(星圖)를 합하여 작성된 것이다. 기존의 조선(朝鮮) 보천가(步天歌)의 배열 순서는 송대(宋代)의 보천가(步天歌)를 따랐으나, 이 보천가(步天歌)는 명대(明代) 이후의 보천가(步天歌)를 따르고 있다. 이 보천가(步天歌)의 성도(星圖)에서 자미원(紫微垣)은 12차(次)와 12진(辰)를 사용하여 구획하고 있고, 28숙(宿)는 3개나 4개씩 묶어서 그리되 각 그룹은 12진(辰)으로도 영역을 표시하였다. 그러나 28숙(宿)의 가결(歌訣)에는 기존의 조선 성도(星圖)들과 마찬가지로 황도십이궁을 채용하고 있다. 각 성도(星圖)는 그 적경 범위 안에 들어있는 모든 별을 그린 것이 아니라 그 원(垣)이나 숙(宿)에 소속된 별자리만을 그렸다. 이 보천가(步天歌)는 의상지(義象志)를 활용했고, 그 주석(注釋)과 비슷한 내용을 1700년 무렵의 중국 문헌에서 찾을 수 있다. 이 문헌들은 1709년에 동시에 조선으로 수입되었다. 우리는 피휘, 참숙(參宿)와 자숙(宿)의 도치, 그리고 1791년에 운관절목(雲觀節目)을 개정할 때 기존의 보천가(步天歌)를 대신하여 이 보천가 취재(取才)에 사용된 사설 등으로부터 우리는 이 보천가(步天歌)의 작성 시기를 고찰해 보았다. 그 결과, 1792년에 출간된 보천가(步天歌)의 성도(星圖)와 주석(注釋)은 그 모본(母本)에 해당하는 것이 중국에서 작성되어 1709년에 조선으로 수입되었고, 1709년과 1791년 사이에 새로운 보천가(步天歌)로 작성되어 사용되다가, 1792년에 출간되었다고 추론하였다. 이러한 추론을 뒷받침하기 위해 필요한 추가 연구에 대해 토의하였다.

MONITORING OBSERVATIONS OF H2O AND SiO MASERS TOWARD POST-AGB STARS

  • Kim, Jaeheon;Cho, Se-Hyung;Yoon, Dong-Hwan
    • 천문학회지
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    • 제49권6호
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    • pp.261-288
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    • 2016
  • We present the results of simultaneous monitoring observations of $H_2O$ $6_{1,6}-5_{2,3}$ (22GHz) and SiO J=1-0, 2-1, 3-2 maser lines (43, 86, 129GHz) toward five post-AGB (candidate) stars, using the 21-m single-dish telescopes of the Korean VLBI Network. Depending on the target objects, 7 - 11 epochs of data were obtained. We detected both $H_2O$ and SiO maser lines from four sources: OH16.1-0.3, OH38.10-0.13, OH65.5+1.3, and IRAS 19312+1950. We could not detect $H_2O$ maser emission toward OH13.1+5.1 between the late OH/IR and post-AGB stage. The detected $H_2O$ masers show typical double-peaked line profiles. The SiO masers from four sources, except IRAS 19312+1950, show the peaks around the stellar velocity as a single peak, whereas the SiO masers from IRAS 19312+1950 occur above the red peak of the $H_2O$ maser. We analyzed the properties of detected maser lines, and investigated their evolutionary state through comparison with the full widths at zero power. The distribution of observed target sources was also investigated in the IRAS two-color diagram in relation with the evolutionary stage of post-AGB stars. From our analyses, the evolutionary sequence of observed sources is suggested as OH65.5+1.3${\rightarrow}$OH13.1+5.1${\rightarrow}$OH16.1-0.3${\rightarrow}$OH38.10-0.13, except for IRAS 19312+1950. In addition, OH13.1+5.1 from which the $H_2O$ maser has not been detected is suggested to be on the gateway toward the post-AGB stage. With respect to the enigmatic object, IRAS 19312+1950, we could not clearly figure out its nature. To properly explain the unusual phenomena of SiO and $H_2O$ masers, it is essential to establish the relative locations and spatial distributions of two masers using VLBI technique. We also include the $1.2-160{\mu}m$ spectral energy distribution using photometric data from the following surveys: 2MASS, WISE, MSX, IRAS, and AKARI (IRC and FIS). In addition, from the IRAS LRS spectra, we found that the depth of silicate absorption features shows significant variations depending on the evolutionary sequence, associated with the termination of AGB phase mass-loss.

삼국시대(三國時代) 의학(醫學)에 관(關)한 문헌적(文獻的) 고찰(考察) (A study of Medicine in the Period of the Three Kingdoms (三國))

  • 신영일;박찬국
    • 대한한의학원전학회지
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    • 제3권
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    • pp.444-500
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    • 1989
  • I have felt seriously a desire to study and analyse the medicine of the period of the Three Kingdoms when I thought and studied the ancient medical history. Therefore in Chapter II I inquired into the background of Politico-social and the currency of thought. In the Chapter III inquired into the system of Medical politics in the period of the Three Kingdoms. In the Chapter IV inquired into the general view of the period of the Three Kingdoms. In the Chapter V inquired into the writings of Medicine and Doctors. From this study, I reached at following-conclusions. 1. The Three Kingdoms are politically opposed to each other, but socialo culturaly cooperated, connected each other to import the technique and thought which developed in China, so generally their system and life pattern are alike. 2. On the system of medical politcics Goguryeo(高句麗) had the system of court phisician, Baek jeo(百濟) had medical doctor and collector in the Ministry of Drug which took charge of teaching and medical treatment and specially had spellchanting doctor who treat epidermic and psychological diease untreated with herb and acupuncture, Shilla(新羅) had the system of Yak chun which was charge of teaching and treatment, and had the Chimbang(針房) which assist doctor in the system of Yagchun(藥典制度). 3. The medical interchange with China made the Three Kingdoms to import the medical books. So the theory of medicine was systematized and the art of treatment developed. In the aspect of Herb the Three Kingdoms and China actively exchange their own district product. 4. The medicine of Three Kingdoms accommodated Yin Yang Ohang theory(陰陽五行說), the theory of body compose with four element(四大 : 地水火風) and the theory of life cultivation and breathing(導引養生說) with Therefore in many aspect of oriental medicine basic theory and treatment would improved. 5. The epidermic diease occurred in period of Three Kingdoms, is represented Yeok(疫), that is after all Ohn Diease(溫病), and epidermic diease, is relfected by earthquake, heavy rain, terrible droughty and eclipse of sun. The treatment of this diease did not developed in that time, we presume that there are many persons killed. 6. As the record of five starr(五星), comet(彗星) and eclipse of sun was showed, the astronomy of oriental medicine in the Three Kingdoms was high level and it became the mothers womb of Korean astronomy. 7. The medicine of the Three Kingdoms, concreted with Chinese medicine and their own ancient one, was reflect on Japanese medicine to improve the medical theory and treatment. 8. The Three Kingdoms peculiarly published Korea Nosabang(高麗老師方) Baekjyeo Shinjipbang(百濟新集方), so this independent medicine reflected on the development of natural hurb(鄕約) of the period of Korea(高麗).

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신법보천가(新法步天歌) 연구 (A Study on New Song of the Sky Pacers)

  • 안상현
    • Journal of Astronomy and Space Sciences
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    • 제26권4호
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    • pp.589-602
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    • 2009
  • 조선(朝鮮)의 보천가(步天歌) 가운데 가장 나중인 1862년에 간행된 신법보천가(新法步天歌)를 연구하였다. 청(淸)에서 들어온 신법천문학(新法天文學)의 영향으로 구도보천가(舊圖步天歌)의 성도(星圖)만을 고쳐서 새로 신도보천가(新圖步天歌)를 간행하였다. 그러나 옛 가결(歌訣)이 새로운 성도(星圖)와 맞지 않았고, 이에 따라 천문학자를 뽑는 과거 시험에 혼란이 일어났다. 이것을 극복하고자 조선(朝鮮)의 관상감(觀象監)은, 1845년에 청(淸)에서 간행된 흠정의상고성속편(欽定儀象考成續編)의 권(卷)3인 성도보천가(星圖步天歌)를 전재하고 주석을 달아, 1862년에 신법보천가(新法步天歌)를 출간하였다. 이 책은 중인(中人)인 이준양(李俊養)이 편찬하고 토대부(土大夫)인 남병길(南秉吉)이 교정(校正)하였다. 우리는 이준양(李俊養)의 열대기를 처음으로 재구성하였다. 신법보천가(新法步天歌)에는 기존의 조선(朝鮮) 보천가(步天歌)들이 갖는 특정을 유지하려는 노력이 엿보인다. 즉, 각 숙(宿)의 제목이 기존의 형식을 따르고 있고, 또한 기존의 조선(朝鮮) 보천가(步天歌)들에 천하기몰(天河起沒)이 있음을 의식하고 흠정의상고성속편(欽定儀象考成續編)의 권(卷)31과 권(卷)32의 천한적도경위도표(天漢赤道經緯度表)를 바탕으로 천한계도(天漢界度)를 저술하였다.

조선조 성리학자 윤지(尹指)의 "둔옹연소천지문답(鈍翁演小天地問答)"에 나타난 의학사상 연구 (Yun-Ji(尹指)'s Medical Thought in "Dunongyeonsocheonjimundap(鈍翁演小天地問答)")

  • 조원준;박완식
    • 대한한의학원전학회지
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    • 제20권4호
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    • pp.187-210
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    • 2007
  • Dunong(鈍翁), Yun-Ji had born by a concubine, and his dream didn't come true for the restraint of his social position, so he tried to train younger men. His writings still remain 4 volumes of "Dunongyeonsocheonjimundap" and "Dunongdongmongmundap(鈍翁童蒙問答)", which may be called its primer. "Dunongyeonsocheonjimundap" is written in question-and-answer form between Chal-Hye-Ja(察慧子) who has a meager knowledge and Sim-Gyeong-Ong(心耕翁) who search for the truth. It is progressed from the law of nature to human's cultivation of the mind so as to reconfirm the recognition of the unity between the heaven and human beings and lead the interpretation and practice of the metaphysical proposition. It is characterized by making use of metrical compositions to induce plain tone of argument. "Dunongdongmongmundap", whereas, uses archaic writings to describe natural science including astronomy to the beginners. Dunong's scholarship is characterized by these: He explained the metaphysical propositions by approaching usual things including oriental medicine practically; He comprised the Confucian concepts intensively to examine the Oriental studies closely; He groped for the outlooks on the world of taking serious view of human being or human body. And his medical thought is characterized by these: He attached importance to the theory of viscera and bowels based on yin-yang and five phase theory; He suggested the concrete yin-yang theory with a viewpoint of qi-blood theory; He considered the concept of 'six' only as mutual rooting of yin and yang and five visceras and six vowels, and denied the traditional six qi concepts; He explained the ghost theories of the metaphysics based on the yin-yang theory to analogize points of sameness between the oriental medicine and the metaphysics; He emphasized restore yang theory. Therefore, we can say that he regarded the human body as small heaven-earth and grafted the abstract propositions into the actuals so as to put the metaphysical propositions in practice.

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일본의 운기학(運氣學)에 관한 연구(硏究) (A Study on Five Circuits and Six Qi Learning of Japan)

  • 윤창열
    • 대한한의학원전학회지
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    • 제31권2호
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    • pp.17-47
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    • 2018
  • Objectives: The three nations of far Northeastern Asia, namely China, Korea, and Japan, have developed a tradition of Asian medicine within a common cultural realm. Studying Japan's Yunqi not only helps our understanding of Japanese traditional medicine, but the course of development taken by the three nations' traditional Asian medicine as a whole. Methods: All books relating to Yunqi published in Japan were studied, with special focus on books that are especially more important. Results: It is assumed that Japan's first book on Yunqi is 吉田宗桂's Ungiileonjib. The Japanese mainstream study on Yunqi is the annotations and studies on Suwenrushiyungilunao, written by Liuwenshu. YunQiLunAoKouYiis the first annotation on Suwenrushiyungilunao and had the greatest impact. Yunqilunjujie is an annotation book written by a Confucian scholar, and Yunqilunaoshuchao an annotation book composed by a Confucian doctor who was a thorough expert on sinology and the annotations ranged greatly from medical books, Confucian books, historical books and hundred schools of books. Aotouyunqilun is the most slight in terms of annotations compared to other annotation books, and Yunqilunaoyanjie is special in that it writes with both Chinese characters and Japanese language in order to help easier understanding by the novice scholars. Conclusions: Suwenrushiyunqilunao includes astronomy, geography, delivery sound, calendar, the eight trigrams, the Twelve laws, Shier chen, Constellation of twenty eight, Thirty-six birds, and secret days, which is leading to further study in these fields. Suwenrushiyunqilunao also contains excerpts from Suwen Liujiecangxianglun to describe the algorithm of the operation of Sun and Moon, which is also leading a further study in the field.

The Synergism of Human Lactobacillaceae and Inulin Decrease Hyperglycemia via Regulating the Composition of Gut Microbiota and Metabolic Profiles in db/db Mice

  • Peifan Li;Tong Tong;Yusong Wu;Xin Zhou;Michael Zhang;Jia Liu;Yongxin She;Zuming Li;Yongli Li
    • Journal of Microbiology and Biotechnology
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    • 제33권12호
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    • pp.1657-1670
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    • 2023
  • This study aimed to evaluate the effects of Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from human feces coordinating with inulin on the composition of gut microbiota and metabolic profiles in db/db mice. These supplements were administered to db/db mice for 12 weeks. The results showed that the Lactobacillaceae coordinating with inulin group (LI) exhibited lower fasting blood glucose levels than the model control group (MC). Additionally, LI was found to enhance colon tissue and increase the levels of short-chain fatty acids. 16S rRNA sequencing revealed that the abundance of Corynebacterium and Proteus, which were significantly increased in the MC group compared with NC group, were significantly decreased by the treatment of LI that also restored the key genera of the Lachnospiraceae_NK4A136_group, Lachnoclostridium, Ruminococcus_gnavus_group, Desulfovibrio, and Lachnospiraceae_UCG-006. Untargeted metabolomics analysis showed that lotaustralin, 5-hydroxyindoleacetic acid, and 13(S)-HpODE were increased while L-phenylalanine and L-tryptophan were decreased in the MC group compared with the NC group. However, the intervention of LI reversed the levels of these metabolites in the intestine. Correlation analysis revealed that Lachnoclostridium and Ruminococcus_gnavus_group were negatively correlated with 5-hydroxyindoleacetic acid and 13(S)-HpODE, but positively correlated with L-tryptophan. 13(S)-HpODE was involved in the "linoleic acid metabolism". L-tryptophan and 5-hydroxyindoleacetic acid were involved in "tryptophan metabolism" and "serotonergic synapse". These findings suggest that LI may alleviate type 2 diabetes symptoms by modulating the abundance of Ruminococcus_gnavus_group and Lachnoclostridium to regulate the pathways of "linoleic acid metabolism", "serotonergic synapse", and" tryptophan metabolism". Our results provide new insights into prevention and treatment of type 2 diabetes.