A time-synchronization strategy for packetized transmission of target position about a large-aperture telescope observation control system has been proposed in this study.Compared with the existing telescope tracking ...A time-synchronization strategy for packetized transmission of target position about a large-aperture telescope observation control system has been proposed in this study.Compared with the existing telescope tracking strategy,the target position packing and sending strategy based on the time synchronization method proposed in this paper has the advantages of high stability and reliability.First,the telescope tracking observation control method was elaborated in this paper,including the motion pattern during telescope tracking.Then,the strategy for packetizes transmission of target positions based on time-synchronization is established and lists the detailed steps.Finally,the performance of the tracking strategy is verified using the 2.5 m telescope for the simulated uniform speed star and the blind-tracking fixed star HIP 31216,respectively.The test results show that the accuracy root mean square of the tracking strategy proposed in this paper is less than 0".02 at 30 minutes,and the performance is much better than the design requirement of 0".3.The most important advantage of this tracking strategy is that the telescope can guarantee normal tracking for a certain period of time even if the hardware or software of the host computer is abnormal.展开更多
Objective： To study the chemical constituents from the Et OAc extract of endophytic fungal Plectosphaerella cucumerina YCTA2 Z1.Methods： The chemical constituents were isolated and purified by silica gel column,Seph...Objective： To study the chemical constituents from the Et OAc extract of endophytic fungal Plectosphaerella cucumerina YCTA2 Z1.Methods： The chemical constituents were isolated and purified by silica gel column,Sephadex LH-20,and reverse-phase C-18 column chromatography as well as crystallization.Results： Thirteen compounds were isolated from the EtOAc extract of the fungal strain YCTA2 Z1.Their chemical structures were elucidated according to the spectral evidence.They were identified as caudatin（1）,baishouwubenzophenone（2）,cynandione B（3）,asterbatanoside A（4）,p-hydroxyphenethyl-O-β-D-glycoside（5）,caffeic acid（6）,ferulic acid（7）,2,5-dihydroxyacetophenone（8）,protocatechuic acid（9）,vanillic acid（10）,stearic acid（11）,azelaic acid（12）,and succinic acid（13）.Conclusions： It is the first chemical study on endophytic fungi from Cynanchum auriculatum and all the compounds are obtained from the species,the genus,as well as the family Plectosphaerellaceae for the first time.展开更多
基金supported by the National Natural Science Foundation of China(grant Nos.11973065 and U1931207)Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB449)to this paper+1 种基金financial support from China Scholarship Council(No.CSC201904910254)Chinese Academy of Sciences Public Study Abroad Fund(Lingzhe Xu)。
文摘A time-synchronization strategy for packetized transmission of target position about a large-aperture telescope observation control system has been proposed in this study.Compared with the existing telescope tracking strategy,the target position packing and sending strategy based on the time synchronization method proposed in this paper has the advantages of high stability and reliability.First,the telescope tracking observation control method was elaborated in this paper,including the motion pattern during telescope tracking.Then,the strategy for packetizes transmission of target positions based on time-synchronization is established and lists the detailed steps.Finally,the performance of the tracking strategy is verified using the 2.5 m telescope for the simulated uniform speed star and the blind-tracking fixed star HIP 31216,respectively.The test results show that the accuracy root mean square of the tracking strategy proposed in this paper is less than 0".02 at 30 minutes,and the performance is much better than the design requirement of 0".3.The most important advantage of this tracking strategy is that the telescope can guarantee normal tracking for a certain period of time even if the hardware or software of the host computer is abnormal.
基金National Natural Science Foundation of China (21502014,81673017,51408094)Natural Science Foundation of Liaoning Province,China (201602114)Research Foundation of Educational Committee of Liaoning Province,China (JDL2017027)
文摘Objective： To study the chemical constituents from the Et OAc extract of endophytic fungal Plectosphaerella cucumerina YCTA2 Z1.Methods： The chemical constituents were isolated and purified by silica gel column,Sephadex LH-20,and reverse-phase C-18 column chromatography as well as crystallization.Results： Thirteen compounds were isolated from the EtOAc extract of the fungal strain YCTA2 Z1.Their chemical structures were elucidated according to the spectral evidence.They were identified as caudatin（1）,baishouwubenzophenone（2）,cynandione B（3）,asterbatanoside A（4）,p-hydroxyphenethyl-O-β-D-glycoside（5）,caffeic acid（6）,ferulic acid（7）,2,5-dihydroxyacetophenone（8）,protocatechuic acid（9）,vanillic acid（10）,stearic acid（11）,azelaic acid（12）,and succinic acid（13）.Conclusions： It is the first chemical study on endophytic fungi from Cynanchum auriculatum and all the compounds are obtained from the species,the genus,as well as the family Plectosphaerellaceae for the first time.
