We report our new results on Herbig-Haro (HH) objects in the star forming region of Taurus from a wide-field survey with the 60/90 cm Schmidt telescope of the Beijing Astronomical Observatory. This survey using CCD im...We report our new results on Herbig-Haro (HH) objects in the star forming region of Taurus from a wide-field survey with the 60/90 cm Schmidt telescope of the Beijing Astronomical Observatory. This survey using CCD imaging with a narrow band [SII] filter and an intermediate band [BATC10] filter covered approximately 30 square degrees in Taurus. Besides confirming the known HH Objects in the region, we discovered seven new HH candidates, and groups. Six of these are HH 701A-B, HH 702A-D, HH 703, HH 704A-D, HH 705, HH 706 and the seventh is a group, a new component of HH 319, labeled HH 319B-D. Based on the large-scale distribution of pre-main-sequence (PMS) stars in Taurus, we analyze statistically the most probable distance from the HH objects to each PMS star, from which we estimate the typical timescale of these HH objects to be between (1.3?2.0)×10<SUP>4</SUP> yrs; and we also obtain the birth rates of HH objects: 0.447±0.198 for Class I PMS stars, 0.360±0.222 for Class II PMS stars, and ?0.148±0.234 for Class III PMS stars.展开更多
With today's economic globalization,inter-provincial trade plays an important role in a country's economy.This paper is the first to adopt the input-output tables of 30 Chinese provinces and to summarize the e...With today's economic globalization,inter-provincial trade plays an important role in a country's economy.This paper is the first to adopt the input-output tables of 30 Chinese provinces and to summarize the evolution of China's inter-provincial trade from1987 to 2007.This paper reaches the following conclusions.First,China's inter-provincial trade has sustained a period of rapid growth.In 2007,the total volume of inter-provincial trade was twice the amount of international trade,with the eastern region accounting for the majority of the inter-provincial trade volume.GDP may have a greater effect on interprovincial trade than geographic distance does.Second,inter-provincial trade maintains a high level of concentration and overlaps with the high concentration of GDP.Third,the inter-provincial trade dependence of Chinese provinces tends to increase,an indication of the growing domestic market integration.Moreover,the eastern region's dependence on inter-provincial trade is higher than the central and western regions'.Fourth,the share of inter-provincial trade in the overall external trade of Chinese provinces has a declining tendency,which indicates a slower process of China's domestic market integration compared with international market integration.However,in terms of proportion,the external trade of most Chinese provinces is still dominated by inter-provincial trade.Fifth,most provinces with longstanding inter-provincial trade deficits are in the central and western regions.展开更多
We present a multi-line study of the massive star-forming region IRAS 22506＋5944. A new 6.7 GHz methanol maser was detected. ^12CO, 13CO, C180 and HCO＋ J = 1 - 0 transition observations reveal a star-formation compl...We present a multi-line study of the massive star-forming region IRAS 22506＋5944. A new 6.7 GHz methanol maser was detected. ^12CO, 13CO, C180 and HCO＋ J = 1 - 0 transition observations reveal a star-formation complex consisting mainly of two cores. The dominant core has a mass of more than 200 Mo, while the other one is only about 35 340. Both cores are obviously at different evolutionary stages. A 12CO energetic bipolar outflow was detected with an outflow mass of about 15 Mo.展开更多
基金Supported by the National Natural Science Foundation of China
文摘We report our new results on Herbig-Haro (HH) objects in the star forming region of Taurus from a wide-field survey with the 60/90 cm Schmidt telescope of the Beijing Astronomical Observatory. This survey using CCD imaging with a narrow band [SII] filter and an intermediate band [BATC10] filter covered approximately 30 square degrees in Taurus. Besides confirming the known HH Objects in the region, we discovered seven new HH candidates, and groups. Six of these are HH 701A-B, HH 702A-D, HH 703, HH 704A-D, HH 705, HH 706 and the seventh is a group, a new component of HH 319, labeled HH 319B-D. Based on the large-scale distribution of pre-main-sequence (PMS) stars in Taurus, we analyze statistically the most probable distance from the HH objects to each PMS star, from which we estimate the typical timescale of these HH objects to be between (1.3?2.0)×10<SUP>4</SUP> yrs; and we also obtain the birth rates of HH objects: 0.447±0.198 for Class I PMS stars, 0.360±0.222 for Class II PMS stars, and ?0.148±0.234 for Class III PMS stars.
基金National Social Science Foundation for the Youth Scholars of China:The Internal Origins of Chinese External Imbalances(Grant No.12 CJL055)Educational Development Foundation of Department of International Economic and Trade,Xiamen University:Research on the Effect of Outsourcing on China's Economy(Grant No.201112111)Humanities and Social Science Project for the Youth Scholars of the Ministry of Education:Research on China's Current Account Adjustment Mode Under the Public Finance(Grant No.11YJC790281)
文摘With today's economic globalization,inter-provincial trade plays an important role in a country's economy.This paper is the first to adopt the input-output tables of 30 Chinese provinces and to summarize the evolution of China's inter-provincial trade from1987 to 2007.This paper reaches the following conclusions.First,China's inter-provincial trade has sustained a period of rapid growth.In 2007,the total volume of inter-provincial trade was twice the amount of international trade,with the eastern region accounting for the majority of the inter-provincial trade volume.GDP may have a greater effect on interprovincial trade than geographic distance does.Second,inter-provincial trade maintains a high level of concentration and overlaps with the high concentration of GDP.Third,the inter-provincial trade dependence of Chinese provinces tends to increase,an indication of the growing domestic market integration.Moreover,the eastern region's dependence on inter-provincial trade is higher than the central and western regions'.Fourth,the share of inter-provincial trade in the overall external trade of Chinese provinces has a declining tendency,which indicates a slower process of China's domestic market integration compared with international market integration.However,in terms of proportion,the external trade of most Chinese provinces is still dominated by inter-provincial trade.Fifth,most provinces with longstanding inter-provincial trade deficits are in the central and western regions.
基金supported by the National Natural Science Foundation of China(Grant Nos.10673024,10733030,10703010 and 10621303)the National Basic Research Program of China-973 Program(2007CB815403)
文摘We present a multi-line study of the massive star-forming region IRAS 22506＋5944. A new 6.7 GHz methanol maser was detected. ^12CO, 13CO, C180 and HCO＋ J = 1 - 0 transition observations reveal a star-formation complex consisting mainly of two cores. The dominant core has a mass of more than 200 Mo, while the other one is only about 35 340. Both cores are obviously at different evolutionary stages. A 12CO energetic bipolar outflow was detected with an outflow mass of about 15 Mo.
