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Elizaveta E. Antonova Ilya L. Ovchinnikov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2001,28(12):1747-1752
Theory of the plasma sheet with medium-scale developed turbulence gives the possibility to explain the main processes of plasma sheet bifurcation and theta-aurora formation during IMF Bz > 0. The model suggests that during IMF Bz > 0 small bulge structure in the plasma sheet center is formed. The polarization of the bulge due to dawnward electron motion and duskward ion motion decreases the large-scale electric field in the bulge region. The decrease of the large-scale field in the conditions of constant coefficient of diffusion leads to the bulge growth. The results of plasma sheet bifurcation and theta-aurora formation modelling are presented. 相似文献
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Maria S. Pulinets Elizaveta E. Antonova Maria O. Riazantseva Svetlana S. Znatkova Igor P. Kirpichev 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
Crossings of the magnetopause near the subsolar point are analyzed using data of THEMIS mission. Variations of the magnetic field near magnetopause measured by one of THEMIS satellites are studied and compared with simultaneous measurements in the solar wind by another THEMIS satellite. The time delay of the solar wind arrival at the subsolar point of the magnetopause is taken into account. 30 and 90 s averaging of the magnetic field in the magnetosheath is produced. The results of averaging are compared with the results of measurements in the solar wind before the bow shock and foreshock. It is shown, that Bx component of the magnetic field near magnetopause is near to zero, which supports the possibility to consider the magnetopause as the tangential discontinuity. Comparatively good correlation of By component in the solar wind and near the magnetopause is observed. The correlation of Bz component near the magnetopause and IMF is practically absent, the sign of the Bz near the subsolar point does not coincide with the sign of IMF Bz in ∼30% cases. 相似文献
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Olga Avercheva Yuliy A. Berkovich Svetlana Smolyanina Elizaveta Bassarskaya Sergey Pogosyan Vasiliy Ptushenko Alexei Erokhin Tatiana Zhigalova 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
Currently light emitting diodes (LEDs) are considered to be most preferable source for space plant growth facilities. We performed a complex study of growth and photosynthesis in Chinese cabbage plants (Brassica chinensis L.) grown with continuous LED lighting based on red (650 nm) and blue (470 nm) LEDs with a red to blue photon ratio of 7:1. Plants grown with high-pressure sodium (HPS) lamps were used as a control. PPF levels used were about 100 μmol/(m2 s) (PPF 100) and nearly 400 μmol/(m2 s) (PPF 400). One group of plants was grown with PPF 100 and transferred to PPF 400 at the age of 12 days. Plants were studied at the age of 15 and 28 days (harvest age); some plants were left to naturally end their life cycle. We studied a number of parameters reflecting different stages of photosynthesis: photosynthetic pigment content; chlorophyll fluorescence parameters (photosystem II quantum yield, photochemical and non-photochemical chlorophyll fluorescence quenching); electron transport rate, proton gradient on thylakoid membranes (ΔpH), and photophosphorylation rate in isolated chloroplasts. We also tested parameters reflecting plant growth and productivity: shoot and root fresh and dry weight, sugar content and ascorbic acid content in shoots. Our results had shown that at PPF 100, plants grown with LEDs did not differ from control plants in shoot fresh weight, but showed substantial differences in photophosphorylation rate and sugar content. Differences observed in plants grown with PPF 100 become more pronounced in plants grown with PPF 400. Most parameters characterizing the plant photosynthetic performance, such as photosynthetic pigment content, electron transport rate, and ΔpH did not react strongly to light spectrum. Photophosphorylation rate differed strongly in plants grown with different spectrum and PPF level, but did not always reflect final plant yield. Results of the present work suggest that narrow-band LED lighting caused changes in Chinese cabbage plants on levels of the photosynthetic apparatus and the whole plant, concerning its development and adaptation to a varying PPF level. 相似文献
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