This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the f...This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the following temperatures： T1 = 24 hr at 25℃, T2= 16 hr at 25 ℃ ＋ 8 hr at 10 ℃, T3= 12 hr at 25 ℃ ＋ 12 hr at 10℃ and T4= 8 hr at 25℃ ＋ 16 hr at 10℃. The germination percentage was increased by diurnal temperature fluctuations, however all of treatments extended MTG compared to control （T1）. Temperature affected the quality of roots, in a matter that high constant temperature resulted in dichotomous （forked） roots during seed germination of pistachio. The response of cultivars was different in this case, so that, Badami-e-Zarand had higher dichotomous root percentage. This disorder can be decreased by diurnal temperature fluctuation.展开更多
Polymeric biosurfactants were prepared by the transesterification reaction between vinyl laurate （VILA） and carboxymethylcellulose （CMC）. The reaction was performed in two different reaction media （（A） DMF/pTSA...Polymeric biosurfactants were prepared by the transesterification reaction between vinyl laurate （VILA） and carboxymethylcellulose （CMC）. The reaction was performed in two different reaction media （（A） DMF/pTSA and （B） DMF/K2CO3） at various reaction conditions and using microwave radiation with controlled power as heating source. The obtained water-soluble VILA-CMC derivatives were characterized by FT-IR spectroscopy and their surface-active properties evaluated. All derivatives showed a very low esterification extent and moderate surface tension lowering effect. Nevertheless, they exhibited significant emulsifying efficiency comparable to that of the synthetic surfactant, Tween 20. The results suggested that suitable surface-active VILA-CMC derivatives can be prepared under microwave heating at low microwave power and reaction times in the range of few minutes, which represents a great advantage in comparison to transesterification reactions lasting up to 6 h at conventional heating.展开更多
The Unified S-Band （USB） ranging/Doppler system and the Very Long Baseline Interferometry （VLBI） system as the ground tracking system jointly supported the lunar orbit capture of both Chang＇E-2 （CE-2） and Chang...The Unified S-Band （USB） ranging/Doppler system and the Very Long Baseline Interferometry （VLBI） system as the ground tracking system jointly supported the lunar orbit capture of both Chang＇E-2 （CE-2） and Chang＇E-1 （CE-1） missions. The tracking system is also responsible for providing precise orbits for scientific data processing. New VLBI equipment and data processing strategies have been proposed based on CE-1 experiences and implemented for CE-2. In this work the role VLBI tracking data played was reassessed through precision orbit determination （POD） experiments for CE-2. Significant improve- ment in terms of both VLBI delay and delay rate data accuracy was achieved with the noise level of X-band band-width syn- thesis delay data reaching 0.2-0.3 ns. Short-arc orbit determination experiments showed that the combination of only 15 min＇s range and VLBI data was able to improve the accuracy of 3 h＇s orbit using range data only by a 1-1.5 order of magnitude, confirming a similar conclusion for CE-1. Moreover, because of the accuracy improvement, VLBI data was able to contribute to CE-2＇s long-arc POD especially in the along-track and orbital normal directions. Orbital accuracy was assessed through the orbital overlapping analysis （2 h arc overlapping for 18 h POD arc）. Compared with about 100 m position error of CE-l＇s 200 kin x 200 km lunar orbit, for CE-2＇s 100 km x 100 km lunar orbit, the position errors were better than 31 and 6 m in the radial direction, and for CE-2＇s 15 km^100 km orbit, the position errors were better than 45 and 12 m in the radial direction. In addi- tion, in trying to analyze the Delta Differential One-Way Ranging （ADOR） experiments data we concluded that the accuracy of ADOR delay was dramatically improved with the noise level better than 0.1 ns and systematic errors better calibrated, and the Short-arc POD tests with ADOR data showed excellent results. Although unable to support the development of an independent lunar gravity model, the tracking data of CE-2 provided evaluations of different lunar gravity models through POD. It is found that for the 100 km x 100 km lunar orbit, with a degree and order expansion up to 165, JPL＇s gravity model LP165P did not show noticeable improvement over Japan＇s SGM series models （100x100）, but for the 15 kmxl00 km lunar orbit, a higher de- gree-order model can significantly improve the orbit accuracy.展开更多
文摘This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the following temperatures： T1 = 24 hr at 25℃, T2= 16 hr at 25 ℃ ＋ 8 hr at 10 ℃, T3= 12 hr at 25 ℃ ＋ 12 hr at 10℃ and T4= 8 hr at 25℃ ＋ 16 hr at 10℃. The germination percentage was increased by diurnal temperature fluctuations, however all of treatments extended MTG compared to control （T1）. Temperature affected the quality of roots, in a matter that high constant temperature resulted in dichotomous （forked） roots during seed germination of pistachio. The response of cultivars was different in this case, so that, Badami-e-Zarand had higher dichotomous root percentage. This disorder can be decreased by diurnal temperature fluctuation.
文摘Polymeric biosurfactants were prepared by the transesterification reaction between vinyl laurate （VILA） and carboxymethylcellulose （CMC）. The reaction was performed in two different reaction media （（A） DMF/pTSA and （B） DMF/K2CO3） at various reaction conditions and using microwave radiation with controlled power as heating source. The obtained water-soluble VILA-CMC derivatives were characterized by FT-IR spectroscopy and their surface-active properties evaluated. All derivatives showed a very low esterification extent and moderate surface tension lowering effect. Nevertheless, they exhibited significant emulsifying efficiency comparable to that of the synthetic surfactant, Tween 20. The results suggested that suitable surface-active VILA-CMC derivatives can be prepared under microwave heating at low microwave power and reaction times in the range of few minutes, which represents a great advantage in comparison to transesterification reactions lasting up to 6 h at conventional heating.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10703011 and11073047)the Science and Technology Commission of Shanghai (GrantNo. 06DZ22101)the National High Technology Research and Development Program of China (Grant No. 2010AA122202)
文摘The Unified S-Band （USB） ranging/Doppler system and the Very Long Baseline Interferometry （VLBI） system as the ground tracking system jointly supported the lunar orbit capture of both Chang＇E-2 （CE-2） and Chang＇E-1 （CE-1） missions. The tracking system is also responsible for providing precise orbits for scientific data processing. New VLBI equipment and data processing strategies have been proposed based on CE-1 experiences and implemented for CE-2. In this work the role VLBI tracking data played was reassessed through precision orbit determination （POD） experiments for CE-2. Significant improve- ment in terms of both VLBI delay and delay rate data accuracy was achieved with the noise level of X-band band-width syn- thesis delay data reaching 0.2-0.3 ns. Short-arc orbit determination experiments showed that the combination of only 15 min＇s range and VLBI data was able to improve the accuracy of 3 h＇s orbit using range data only by a 1-1.5 order of magnitude, confirming a similar conclusion for CE-1. Moreover, because of the accuracy improvement, VLBI data was able to contribute to CE-2＇s long-arc POD especially in the along-track and orbital normal directions. Orbital accuracy was assessed through the orbital overlapping analysis （2 h arc overlapping for 18 h POD arc）. Compared with about 100 m position error of CE-l＇s 200 kin x 200 km lunar orbit, for CE-2＇s 100 km x 100 km lunar orbit, the position errors were better than 31 and 6 m in the radial direction, and for CE-2＇s 15 km^100 km orbit, the position errors were better than 45 and 12 m in the radial direction. In addi- tion, in trying to analyze the Delta Differential One-Way Ranging （ADOR） experiments data we concluded that the accuracy of ADOR delay was dramatically improved with the noise level better than 0.1 ns and systematic errors better calibrated, and the Short-arc POD tests with ADOR data showed excellent results. Although unable to support the development of an independent lunar gravity model, the tracking data of CE-2 provided evaluations of different lunar gravity models through POD. It is found that for the 100 km x 100 km lunar orbit, with a degree and order expansion up to 165, JPL＇s gravity model LP165P did not show noticeable improvement over Japan＇s SGM series models （100x100）, but for the 15 kmxl00 km lunar orbit, a higher de- gree-order model can significantly improve the orbit accuracy.
