208 resultados para stamping variation
Resumo:
Chinese Academy of Sciences [KZCX2-YW-315, KZCX2-YW-Q1-01]; National Natural Science Foundation of China [40625002, 90502009, 200905006]; Office of Science (BER), U. S. Department of Energy ; EU/FP7 [212250]
Resumo:
Plant traits and individual plant biomass allocation of 57 perennial herbaceous species, belonging to three common functional groups (forbs, grasses and sedges) at subalpine (3700 m ASL), alpine (4300 m ASL) and subnival (>= 5000 m ASL) sites were examined to test the hypothesis that at high altitudes, plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts, especially storage organs, as altitude increases, so as to geminate and resist environmental stress. However, results indicate that some divergence in biomass allocation exists among organs. With increasing altitude, the mean fractions of total biomass allocated to aboveground parts decreased. The mean fractions of total biomass allocation to storage organs at the subalpine site (7%+/- 2% S.E.) were distinct from those at the alpine (23%+/- 6%) and subnival (21%+/- 6%) sites, while the proportions of green leaves at all altitudes remained almost constant. At 4300 m and 5000 m, the mean fractions of flower stems decreased by 45% and 41%, respectively, while fine roots increased by 86% and 102%, respectively. Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation, while sedges showed opposite trends. For all three functional groups, leaf area ratio and leaf area root mass ratio decreased, while fine root biomass increased at higher altitudes. Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots, while the proportion of leaves remained stable. It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots. In contrast to forbs and grasses that had high mycorrhizal infection, sedges had higher single leaf area and more root fraction, especially fine roots.
Resumo:
Birefringent ring-banded spherulites with radial periodic variation of thicknesses were grown from poly(epsilon-caprolactone) (PCL) solutions under conditions for which the Solution concentration was held constant during the whole development of the morphology. The as-grown ring-banded spherulites were investigated by optical (OM) and atomic force (AFM) microscopies, by transmission electron microscopy (TEM) of samples sectioned parallel to the plane of film, and also by electron diffraction (ED) and grazing incidence X-ray diffraction (GIXD) techniques.
Resumo:
To study the content variation of ginsenosides and alkaloids during combination of ginseng with veratrum nigrum, the ginsenosides and alkaloids in the decoction of ginseng with veratrum nigrum were analyzed and compared by high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) and electrospray ionization-mass spectrometry (ESI-MS). In the compatible decoction, eight ginsenosides and eight alkaloids. were detected, and the contents of six ginsenosides were found to be reduced, on the contrary, the contents of six alkaloids were increased. During combination of ginseng with veratrum nigrum, the contents of ginsenosides were reduced and those of the toxic alkaloids were increased. From the chemical point of view, the traditional theory is right that ginseng and veratrum nigrum are incompatible with each other.
Resumo:
A high performance liquid chroatography-electrospray ionization-mass spectrometric method was developed for analysis and identification of ginsenosides from the decoction of ginseng, ginseng with trogopteroum feces and ginseng with semen raphani. Ten ginsenosides were separated and detected. The content variation of these ginsenosides was researched. The experimental results showed, that ginsenosides were less in compatible decoction than in separate one expect Ro. the stripping of ginsenosides were restrained by semen raphani and during combination of ginseng with trogopteroum feces, the precipitates were produced by ginsenosides.