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111.
黑龙江鸡西早白垩世侧羽叶一新种-城子河侧羽叶 (Pterophyllum chengzihense sp.nov.) 总被引:1,自引:0,他引:1
根据产于黑龙江鸡西早白垩世城子河组一种侧羽叶属(Pterophyllum)植物化石的外形特征及表皮构造研究,确认该种属于本内苏铁类(Bennettitales)植物,并有别于其他植物类群。据此,新建一新种—城子河侧羽叶(新种)Pterophyllumchengzihensesp.nov.,并讨论了该新种在研究中国东北地区早白垩世植物化石中的意义。 相似文献
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113.
Antonio Tadeu dos Reis Christian Gorini Alain Mauffret Wiktor Weibull 《Comptes Rendus Geoscience》2004,336(2):143-150
The Marseilles (also called Marseilles/Planier) and Grand Rhone sedimentary ridges, offshore the Gulf of Lions, western Mediterranean Sea, are generated by sediment spillover funnelled by the Marseilles and Grand-Rhone canyons, respectively. We show that the Marseilles and Grand-Rhone canyon directions are tectonically conditioned by Plio-Quaternary salt-induced sea-floor relief. Overburden extension in the area created an assemblage of listric faults running parallel to the strike of the continental margin. This salt-induced topography resulted in accentuated fault scarps impacting the sea-floor morphology and forcing submarine valleys to deflect to the east. Gravity-induced extension equally influenced the morphological pattern of the valley overbanking deposits. Sediment spillover occurred on both flanks of the canyons, but because active faulting generated space accommodation for overflow deposits, it inhibited the development of typical levee morphology along the canyons' left flanks. To cite this article: A.T. dos Reis, C. R. Geoscience 336 (2004). 相似文献
114.
The behaviour of a karstic spring (Bittit spring, Middle Atlas, Morocco) subjected to a prolonged drought (>20 yr), is analysed using spring hydrographs analysis methods and correlation and spectral methods. Two series of discharges, corresponding to a normal rainfall period and a drought period, are analysed. The results show that the karstic system is inertial, with very significant storage. However, in spite of the great regulating capacity of the storage, the long drought period significantly reduced the spring discharges, due to less diversified inputs, and to the karstic system storage depletion. To cite this article: F. Amraoui et al., C. R. Geoscience 336 (2004). 相似文献
115.
A New Genus of Psittacosauridae (Dinosauria: Ornithopoda) and the Origin and Early Evolution of Marginocephalian Dinosaurs 总被引:2,自引:0,他引:2
YOU Hailu Institute of Geology Chinese Academy of Geological Sciences Beijing XU Xing WANG XiaolinInstitute of Vertebrate Paleontology Paleoanthropology Chinese Academy of Sciences Beijing 《《地质学报》英文版》2003,77(1):15-20
An almost complete juvenile dinosaur skull with lower jaw was discovered from the Early Cretaceous Yixian Formation in Beipiao, Liaoning Province, China. Here, the specimen is described and a cladistic analysis is performed in order to find its phylogenetic relationships. The result shows that this specimen represents a new genus of Psittacosauridae, Hongshanosaurus houi, gen. et sp. nov., and confirms the monophyletic status for Ceratopsia and Marginocephalia. However, Heterodontosaurus is found to be the sister taxon to Marginocephalia, rather than a basal Omithopoda. 相似文献
116.
Forbes ogives show alternations of dark (ice + mineral dust) and light bands at the surface of certain glaciers. We propose to understand their origin by the influence of the content of mineral matter on the lowering of the temperature and pressure of ice fusion and upon the increase of fusion velocity. We are then in an unstable situation: a local increase in the mineral content being induced by the fusion process, which in turn increases; this creates a dark band. The movement of the glacier cannot keep up with the fusion: pressure is lowered again below the fusion point, and a white band is formed. To cite this article: B. Guy et al., C. R. Geoscience 334 (2002) 1061–1070. 相似文献
117.
Jean-François Royer Daniel Cariolle Fabrice Chauvin Michel Déqué Hervé Douville Rong-Ming Hu Serge Planton Annie Rascol Jean-Louis Ricard David Salas Y Melia Florence Sevault Pascal Simon Samuel Somot Sophie Tyteca Laurent Terray Sophie Valcke 《Comptes Rendus Geoscience》2002,334(3):147-154
Two climate simulations of 150 years, performed with a coupled ocean/sea-ice/atmosphere model including stratospheric ozone, respectively with and without heterogeneous chemistry, simulate the tropospheric warming associated with an increase of the greenhouse effect of carbon dioxide and other trace gases since 1950 and their impact on sea–ice extent, as well as the stratospheric cooling and its impact on ozone concentration. The scenario with heterogeneous chemistry reproduces the formation of the ozone hole over the South Pole from the 1970s and its deepening until the present time, and shows that the ozone hole should progressively fill during the coming decades. To cite this article: J.-F. Royer et al., C. R. Geoscience 334 (2002) 147–154. 相似文献
118.
蓝藻钙化普遍发生于淡水和盐水环境,对叠层石的形成和碳循环有重要意义。本文模拟研究了pH值、光照强度、水动力、温度等环境因子对Synechocystis sp.藻类钙化动力学的影响。实验表明,pH值为7.5的弱碱环境和一定强度的水动力条件有利于Synechocystis sp.的钙化,过低或过高的水动力都不利于钙化;在5、15和25℃三个梯度范围内,温度为25℃时有利于钙化,且钙化速率与生物量密切相关;3000 lux的光照强度下,Synechocystis sp.钙化速率最大,更高的强度下钙化速率反而急剧下降,低浓度钙离子发生的钙化作用以生物钙化为主,高浓度下以生物引发的物理化学钙化为主。 相似文献
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120.
YONG Wai-Kuan LIM Phaik-Eem VELLO Vejeysri SIM Kae-Shin ABDUL MAJID Nazia MUSTAFA Emienour Muzalina NIK SULAIMAN Nik Meriam LIEW Kan-Ern CHEN Brenna Jia-Tian PHANG Siew-Moi 《海洋湖沼学报(英文)》2019,(1):186-198
A freshwater green microalgae Chlorella sp., UMACC344 was shown to produce high lipid content and has the potential to be used as feedstock for biofuel production. In this study, photosynthetic effciency, biochemical pro?les and non-targeted metabolic pro?ling were studied to compare between the nitrogen-replete and deplete conditions. Slowed growth, change in photosynthetic pigments and lowered photosynthetic effciency were observed in response to nitrogen deprivation. Biochemical pro?les of the cultures showed an increased level of carbohydrate, lipids and total fatty acids, while the total soluble protein content was lowered. A trend of fatty acid saturation was observed in the nitrogen-deplete culture with an increase in the level of saturated fatty acids especially C16:0 and C18:0, accompanied by a decrease in proportions of monounsaturated and polyunsaturated fatty acids. Fifty-nine metabolites, including amino acids, lipids, phytochemical compounds, vitamins and cofactors were signi?cantly dysregulated and annotated in this study. Pathway mapping analysis revealed a rewiring of metabolic pathways in the cells, particularly purine, carotenoid, nicotinate and nicotinamide, and amino acid metabolisms. Within the treatment period of nitrogen deprivation, the key processes involved were reshu ? ing of nitrogen from proteins and photosynthetic machinery, together with carbon repartitioning in carbohydrates and lipids. 相似文献