The Yangtze River estuary is the main production area of Anguilla japonica in China,as well as the only existing fishery area for adult eels.Japanese eels are distributed in the main rivers and many tributaries from t...The Yangtze River estuary is the main production area of Anguilla japonica in China,as well as the only existing fishery area for adult eels.Japanese eels are distributed in the main rivers and many tributaries from the Yangtze River estuary to the upper Jinsha River,which extend to nearly 3 000 km.However,their migration behaviors remain relatively unknown.We analyzed the biological characteristics of 153 specimens of silver eels collected from the Jingjiang section of Yangtze River（31o30＇N,120o42＇E） between September and November,2008,and tested the sagittal Sr/Ca ratios of 27 specimens.Among the 153 specimens examined,85 were female and 68 were male,which translated to a female-male ratio of 1：0.8.The ages of the female specimens ranged from 3 to 7 a（average 5.52） with an average total length（TL） of（669±80） mm,average body weight（BW） of（555±229）g,average condition factor of 1.77±0.22,and average gonad somatic index（GSI） of 1.32±0.31.The ages of the males ranged from 3 to 5 a（average：4.38） with an average TL of（518±51） mm,average BW of（234±76） g,average condition factor of 1.62±0.18,and average GSI of 0.21±0.11.All biological parameters of females were significantly larger than those of the male specimens（P0.05）.According to the average Sr/Ca ratio（7.99±1.05） ×10-3 of the elver mark of sagitta,17 individuals（62.96%） were river eels and 10 individuals（37.04%） were estuarine eels.Of 16 females,13 individuals（81.25%） were river eels and 3 were estuarine eels,while of 11 males,36.36% were river eels and 63.64% were estuarine eels.The analysis on Sr/Ca ratios for every growth layer group（GLG） indicated there were no significant differences between second-age males and females.However,significant differences were observed between the third-age,fourth-age,and migration-age male and female specimens.This was likely related to the fact that second-age eels of both sexes stay in the same inhabitation waters;however,as they grow older,they move to different areas.展开更多
Chemical investigation of L.sagitta afforded two new cremophilenolides, which were identified as 6beta-angeloyloxy-10beta-hydroxy-8beta-methoxy-cremophil-7(11)-en-12, 8alpha-olide (1) and 6beta, 8beta-dimethoxy-10beta...Chemical investigation of L.sagitta afforded two new cremophilenolides, which were identified as 6beta-angeloyloxy-10beta-hydroxy-8beta-methoxy-cremophil-7(11)-en-12, 8alpha-olide (1) and 6beta, 8beta-dimethoxy-10beta-hydroxy-eremophil-7(11)-en-12, 8alpha-olide (2). Their structures were established by spectroscopic methods including 2D NMR experiments.展开更多
Ligularia sp. have the antibiotic and antiphlogistic effects. There have been many reports on the chemical constituents of them. However, no report has been given on the chemical constituents of Ligularia sagitta up t...Ligularia sp. have the antibiotic and antiphlogistic effects. There have been many reports on the chemical constituents of them. However, no report has been given on the chemical constituents of Ligularia sagitta up to now. In this note, we report a new compound which was isolated from the rhizome of the plant. It was identified as a lactone of new carbon skeleton by ELMS, <sup>13</sup>C NMR, DEPT, <sup>1</sup>H NMR and X-ray crystal structural analysis. It was named Sagittolactone.展开更多
Purpose In the standard design method of straight dipole magnets,the good field region is symmetric to the magnet mechanical center both in 2D and in 3D,so the obtained field quality is not the actual one because the ...Purpose In the standard design method of straight dipole magnets,the good field region is symmetric to the magnet mechanical center both in 2D and in 3D,so the obtained field quality is not the actual one because the field integration lines are not consistent with the curved beam paths.In this paper,an improved method for straight dipole magnets aiming at obtaining accurate field quality is proposed.Methods The field quality is calculated by taking into account the relationship of the good field region to the magnet straight geometry.General description of the improved method is introduced,and two application examples of straight dipole magnets are presented to investigate the detailed field quality difference between the improved and traditional methods.The result of the improved method is also compared with the field quality calculated along particle trajectory in OPERA-3D.Results It is shown that the difference in field quality between the improved and traditional methods cannot be neglected,and the field quality in the improved method is very close to the one calculated along real beam paths.Conclusion The field quality in the improved method is accurate enough for practical application in a straight dipole magnet.展开更多
基金supported by the Chinese National Science Foundation under the Grant(30771650)the Key Programs of Science and Technology Commission Foundation of Shanghai(08391910200)+3 种基金Special Fund for Agroscientific Research in the Public Interest(201203065)Research Fund for the Doctoral Program of Higher Education of China(20070264001)E-class Programs of Shanghai Municipal Education Commission(E03009)the Key Subject Construction of Shanghai(S30701)
文摘The Yangtze River estuary is the main production area of Anguilla japonica in China,as well as the only existing fishery area for adult eels.Japanese eels are distributed in the main rivers and many tributaries from the Yangtze River estuary to the upper Jinsha River,which extend to nearly 3 000 km.However,their migration behaviors remain relatively unknown.We analyzed the biological characteristics of 153 specimens of silver eels collected from the Jingjiang section of Yangtze River（31o30＇N,120o42＇E） between September and November,2008,and tested the sagittal Sr/Ca ratios of 27 specimens.Among the 153 specimens examined,85 were female and 68 were male,which translated to a female-male ratio of 1：0.8.The ages of the female specimens ranged from 3 to 7 a（average 5.52） with an average total length（TL） of（669±80） mm,average body weight（BW） of（555±229）g,average condition factor of 1.77±0.22,and average gonad somatic index（GSI） of 1.32±0.31.The ages of the males ranged from 3 to 5 a（average：4.38） with an average TL of（518±51） mm,average BW of（234±76） g,average condition factor of 1.62±0.18,and average GSI of 0.21±0.11.All biological parameters of females were significantly larger than those of the male specimens（P0.05）.According to the average Sr/Ca ratio（7.99±1.05） ×10-3 of the elver mark of sagitta,17 individuals（62.96%） were river eels and 10 individuals（37.04%） were estuarine eels.Of 16 females,13 individuals（81.25%） were river eels and 3 were estuarine eels,while of 11 males,36.36% were river eels and 63.64% were estuarine eels.The analysis on Sr/Ca ratios for every growth layer group（GLG） indicated there were no significant differences between second-age males and females.However,significant differences were observed between the third-age,fourth-age,and migration-age male and female specimens.This was likely related to the fact that second-age eels of both sexes stay in the same inhabitation waters;however,as they grow older,they move to different areas.
文摘Chemical investigation of L.sagitta afforded two new cremophilenolides, which were identified as 6beta-angeloyloxy-10beta-hydroxy-8beta-methoxy-cremophil-7(11)-en-12, 8alpha-olide (1) and 6beta, 8beta-dimethoxy-10beta-hydroxy-eremophil-7(11)-en-12, 8alpha-olide (2). Their structures were established by spectroscopic methods including 2D NMR experiments.
基金Project supported by the National Natural Science Foundation of China.
文摘Ligularia sp. have the antibiotic and antiphlogistic effects. There have been many reports on the chemical constituents of them. However, no report has been given on the chemical constituents of Ligularia sagitta up to now. In this note, we report a new compound which was isolated from the rhizome of the plant. It was identified as a lactone of new carbon skeleton by ELMS, <sup>13</sup>C NMR, DEPT, <sup>1</sup>H NMR and X-ray crystal structural analysis. It was named Sagittolactone.
文摘Purpose In the standard design method of straight dipole magnets,the good field region is symmetric to the magnet mechanical center both in 2D and in 3D,so the obtained field quality is not the actual one because the field integration lines are not consistent with the curved beam paths.In this paper,an improved method for straight dipole magnets aiming at obtaining accurate field quality is proposed.Methods The field quality is calculated by taking into account the relationship of the good field region to the magnet straight geometry.General description of the improved method is introduced,and two application examples of straight dipole magnets are presented to investigate the detailed field quality difference between the improved and traditional methods.The result of the improved method is also compared with the field quality calculated along particle trajectory in OPERA-3D.Results It is shown that the difference in field quality between the improved and traditional methods cannot be neglected,and the field quality in the improved method is very close to the one calculated along real beam paths.Conclusion The field quality in the improved method is accurate enough for practical application in a straight dipole magnet.
