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91.
The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in late April and mid November to early December respectively, and a phytoplankton bloom appeared in the underlying surface water in mid December following the spring ice algal bloom. The biomass in ice bottom was 1 to 3 orders of magnitude higher than that of surface water. Amphiprora kjellmanii, Berkeleya sp., Navicula glaciei, Nitzschia barkelyi, N. cylindrus /N. curta, N. lecointei and Nitzschia sp. were common in the sea ice temporarily or throughout the study period. The biomass in a certain ice segment was decreased gradually and the dominant species were usually succeeded as the season went on. Nitzschia sublineata and Dactyliosolen antarctica were two seasonal dominant species only observed in underlying water column. The assemblages between bottom of ice and underlying surface water were different except when spring ice algae bloomed. The evidence shows that the ice algal blooms occurred mainly by in situ growth of ice algae, and the phytoplankton bloom was mostly caused by the release of ice algae. 相似文献
92.
Based on the data obtained from tens of the investigated soil profiles scattered over the Fildes Peninsula, King George Island, the maritime Antarctic, the soil-forming processes were discussed. It was concluded that on the weathering crusts resulted from various physical courses, the strong freeze-thaw action within regolith, significant organic matter accumulation, evident leaching and illuviation, as well as initial argillification dominated the formation and development of the soils on the Fildes Peninsula. Furthermore, this study indicated that the juvenility of genesis, poor profile-expression, variation in column thickness, etc. characterized the pedogenetic features of the soils of the Fildes Peninsula. 相似文献
93.
China's eastern coastal area marine hazards (storm surge, erosion and deposition by tidal currents and seawater intrusion)
and the history, present situation, experiences and problems of inhabitants in their fight against marine hazards are discussed
in this paper, which also suggests counter-measures against, and scientific and rational management of, coastal area marine
hazards in order to protect the coastal and estuarine ecosystems. 相似文献
94.
分析了高原地面加热场强度距平指数与四川盆地伏旱及主汛期降水的联系。结果表明,高原前期加热强度同四川盆汛期降水和伏旱程度密切相关。把这些关系引入汛期降水预测模型对提高短期气候预测能力有一定积极意义。 相似文献
95.
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97.
Nano-hematites, i.e., hematites with nanoparticle-, nanorod-, and nanotube-like morphologies, were synthesized via the hydrothermal method by controlling the reaction time, temperature, and reactant concentration. The nano-hematites of different crystal shapes all exhibited band gaps within the visible-light region (1.56–2.1 eV). Further, they showed weak ferromagnetic behavior, and their coercive magnetic field was larger than that of the bulk hematite. Moreover, all the nano-hematites also exhibited high photocatalytic activities during the degradation of methylene blue under visible-light irradiation. The experimental data fitted the Langmuir–Hinshelwood kinetics model very well. The nanorods had the highest photocatalytic rate constant per unit surface area, possibly owing to a higher aspect ratios; this lowers the electron–hole recombination rate. These results suggest that the crystal morphology of hematites has a significant effect on their physical and photocatalytic properties. Therefore, controlling the morphology of the materials is essential for obtaining well-tailored photocatalysts. 相似文献
98.
Delphine Yeghicheyan Cécile Bossy Martine Bouhnik Le Coz Chantal Douchet Guy Granier Alexie Heimburger Francois Lacan Aurélie Lanzanova Tristan C. C. Rousseau Jean‐Luc Seidel Mickaël Tharaud Frédéric Candaudap Jérôme Chmeleff Christophe Cloquet Sophie Delpoux Marie Labatut Rémi Losno Catherine Pradoux Yann Sivry Jeroen E. Sonke 《Geostandards and Geoanalytical Research》2013,37(4):449-467
The natural river water certified reference material SLRS‐5 (NRC‐CNRC) was routinely analysed in this study for major and trace elements by ten French laboratories. Most of the measurements were made using ICP‐MS. Because no certified values are assigned by NRC‐CNRC for silicon and 35 trace element concentrations (rare earth elements, Ag, B, Bi, Cs, Ga, Ge, Li, Nb, P, Rb, Rh, Re, S, Sc, Sn, Th, Ti, Tl, W, Y and Zr), or for isotopic ratios, we provide a compilation of the concentrations and related uncertainties obtained by the participating laboratories. Strontium isotopic ratios are also given. 相似文献
99.
100.