Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
A hydroponic experiment was conducted to elucidate the difference in growth and cell ultrastructure between Tibetan wild and cultivated barley genotypes under moderate (150 mM NaCl) and high (300 mM NaCl) salt stress. The growth of three barley genotypes was reduced significantly under salt stress, but the wild barley XZ16 (tolerant) was less affected relative to cultivated barley Yerong (moderate tolerant) and Gairdner (sensitive). Meanwhile, XZ16 had lower Na⁺ and higher K⁺ concentrations in leaves than other two genotypes. In terms of photosynthetic and chlorophyll fluorescence parameters, salt stress reduced maximal photochemical efficiency (Fv/ Fm), net photosynthetic rate (Pn), stomatal conductance (Gs), and intracellular CO₂ concentration (Ci). XZ16 showed relatively smaller reduction in comparison with the two cultivated barley genotypes. The observation of transmission electron microscopy found that fundamental cell ultrastructure changes happened in both leaves and roots of all barley genotypes under salt NaCl stress, with chloroplasts being most changed. Moreover, obvious difference could be detected among the three genotypes in the damage of cell ultrastructure under salt stress, with XZ16 and Gairdner being least and most affected, respectively. It may be concluded that high salt tolerance in XZ16 is attributed to less Na⁺ accumulation and K⁺ reduction in leaves, more slight damage in cell ultrastructure, which in turn caused less influence on chloroplast function and photosynthesis.
The ammonium sulfate ((NH₄)₂SO₄) seed aerosols commonly found in the Chinese urban atmosphere could affect the formation and aging of secondary organic aerosols (SOA). Aging of aromatic SOA is performed using UV-irradiation of 1,3,5-trimethylbenzene (135-TMB)/CH₃ONO/NO/air mixtures with high concentrations (~100 μg/m³) of (NH₄)₂SO₄ seeds in the laboratory chamber in this study. The particulate products of SOA were measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) in real-time, and fuzzy c-means (FCM) was applied to the mass spectra organic species for clusters. Experimental results indicated that methylglyxoal, 2-methyl-4-oxo-2-pentenal, 4-methyl-1H-imidazole, 4-methyl-imidazole-2-acetaldehyde, and other imidazole derivative compounds are the principal products in the aged particles. Imidazole compounds that can absorb solar radiation effectively were newly detected in the aged 135-TMB SOA with high concentrations of (NH₄)₂SO₄ seed aerosols. These would provide new information for discussing the 135-TMB SOA aging mechanism.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.