The 1998 Leonid meteor shower was observed at the Gaomeigu station of Yunnan Observatory during 5 successive days in November. The visual records indicates that the number of the meteor increased suddenly in the early...The 1998 Leonid meteor shower was observed at the Gaomeigu station of Yunnan Observatory during 5 successive days in November. The visual records indicates that the number of the meteor increased suddenly in the early morning of November 17th in Beijing time, with a maximum of ZHR about 340. But it deceased slowly in the following two days. During the maximum it had a high proportion of about 10 percent of very bright展开更多
On the basis of the observational data obtained by the Sino-Dutch Joint Leonids Observation Team at Delingha Station of Purple Mountain Observatory from Nov. 13 to 18, 1998, and those obtained in other places of China...On the basis of the observational data obtained by the Sino-Dutch Joint Leonids Observation Team at Delingha Station of Purple Mountain Observatory from Nov. 13 to 18, 1998, and those obtained in other places of China during the same period, the distribution characteristics of the 1998 Leonids are analyzed and a three-layer structure of the meteoric shower encountered by the Earth is proposed.展开更多
The Leonid meteor shower in November 1998 was observed widely by astronomers. The first peak, rich in bright meteors, appeared about 16 hours before the predicted maximum of the main shower. The main shower was also o...The Leonid meteor shower in November 1998 was observed widely by astronomers. The first peak, rich in bright meteors, appeared about 16 hours before the predicted maximum of the main shower. The main shower was also observed by both optical and radio methods during 19:00-21:00 UT on Nov. 17, and the radio peak was over 2500h-1. About 18 hours after the main shower, an abnormal phenomenon in the ionosphere was detected by two separate ionosphere observing stations. And the very high abnormal phenomenon maintained over one hour. The phenomenon showed that the ionosphere was injected with a large amount of small dust particles that could not be observed in optical and radio. The Observational results show that the Leonid meteor shower in 1998 had three peaks.展开更多
To this day, the name of choreographer Leonid Yakobson is known only among the dance professionals. However his ballets and dance miniatures, along with the surprising choice of imagery and ballet language, testify th...To this day, the name of choreographer Leonid Yakobson is known only among the dance professionals. However his ballets and dance miniatures, along with the surprising choice of imagery and ballet language, testify that Yakobson has been one of the most outstanding choreographers of the 20th century. The aim of the article is to analyse Leonid Yakobson＇s most distinguished choreographic works. The chosen theme emphasises inovation in the choreographer＇s creative work. The chosen research method is analysis of the choreographed works of Leonid Yakobson.The article results show that his art, based on the experience of the Russian classical school of ballet, combines the early 20th century avant-garde principles with influences from the greatest choreographers of the Russian ballet.展开更多
Here is the first report on the observation of meteor ablation trails with lidar in China.Four long-lived Na ablation trails were observed during the 18/19 Nov.2001 Leonid meteor shower with a sodium resonance lidar o...Here is the first report on the observation of meteor ablation trails with lidar in China.Four long-lived Na ablation trails were observed during the 18/19 Nov.2001 Leonid meteor shower with a sodium resonance lidar over Wuhan.The mean altitude of the 4 trails is 97.95 km,consistent with Leouid high entry velocity(-72km/s).The peak density averages about 3380±3633cm^-3,and the abundance is(2.33±1.49)×10^(8)cm^(-2),both of which are higher than those previously observed for sporadic meteor trails.The RMS width is 359 m and the meteor's age is 81 min,indicating that they are long duration meteor trails.These observation results are quite different from those of sporadic meteor trails,but comparable to the 1998 and 1999 Leonid report.Five night observations from 17 Nov.to 23 Nov.suggest that the 2001 Leouid meteor shower does not have a significant impact on the abundance of the background Na layer.展开更多
文摘The 1998 Leonid meteor shower was observed at the Gaomeigu station of Yunnan Observatory during 5 successive days in November. The visual records indicates that the number of the meteor increased suddenly in the early morning of November 17th in Beijing time, with a maximum of ZHR about 340. But it deceased slowly in the following two days. During the maximum it had a high proportion of about 10 percent of very bright
文摘On the basis of the observational data obtained by the Sino-Dutch Joint Leonids Observation Team at Delingha Station of Purple Mountain Observatory from Nov. 13 to 18, 1998, and those obtained in other places of China during the same period, the distribution characteristics of the 1998 Leonids are analyzed and a three-layer structure of the meteoric shower encountered by the Earth is proposed.
文摘The Leonid meteor shower in November 1998 was observed widely by astronomers. The first peak, rich in bright meteors, appeared about 16 hours before the predicted maximum of the main shower. The main shower was also observed by both optical and radio methods during 19:00-21:00 UT on Nov. 17, and the radio peak was over 2500h-1. About 18 hours after the main shower, an abnormal phenomenon in the ionosphere was detected by two separate ionosphere observing stations. And the very high abnormal phenomenon maintained over one hour. The phenomenon showed that the ionosphere was injected with a large amount of small dust particles that could not be observed in optical and radio. The Observational results show that the Leonid meteor shower in 1998 had three peaks.
文摘To this day, the name of choreographer Leonid Yakobson is known only among the dance professionals. However his ballets and dance miniatures, along with the surprising choice of imagery and ballet language, testify that Yakobson has been one of the most outstanding choreographers of the 20th century. The aim of the article is to analyse Leonid Yakobson＇s most distinguished choreographic works. The chosen theme emphasises inovation in the choreographer＇s creative work. The chosen research method is analysis of the choreographed works of Leonid Yakobson.The article results show that his art, based on the experience of the Russian classical school of ballet, combines the early 20th century avant-garde principles with influences from the greatest choreographers of the Russian ballet.
文摘Here is the first report on the observation of meteor ablation trails with lidar in China.Four long-lived Na ablation trails were observed during the 18/19 Nov.2001 Leonid meteor shower with a sodium resonance lidar over Wuhan.The mean altitude of the 4 trails is 97.95 km,consistent with Leouid high entry velocity(-72km/s).The peak density averages about 3380±3633cm^-3,and the abundance is(2.33±1.49)×10^(8)cm^(-2),both of which are higher than those previously observed for sporadic meteor trails.The RMS width is 359 m and the meteor's age is 81 min,indicating that they are long duration meteor trails.These observation results are quite different from those of sporadic meteor trails,but comparable to the 1998 and 1999 Leonid report.Five night observations from 17 Nov.to 23 Nov.suggest that the 2001 Leouid meteor shower does not have a significant impact on the abundance of the background Na layer.
