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11.
本文研究了虾蟹海产品香味的前体物质在加热前后的变化。实验结果表明:对虾和蟹肌肉中的糖原和不饱和脂肪酸在加热前后含量下降,糖原是Maillard反应的基础物质.不饱和脂肪酸是虾蟹肌肉香味中羰基化合物的前体物质。虾蟹肌肉中主要积累的核苷酸成分AMP在加热后减少,而肌肉提取物中的游离氨基酸和结合氨基酸,特别是疏水氨基酸含量均增加。 相似文献
12.
南海是热带气旋活动较为频繁的地区之一。该地区因其独特的地理环境和复杂的热带大气环流系统,在热带气旋预报工作上存在一定的困难。本文在分析一些气象图表资料的基础上,对2002年第20号热带风暴(米克拉)的形成、发展及消亡进行了探讨和研究。主要从形成的背景环流,气旋的结构等方面入手,总结出一些该气旋所具备韵特有流场,从而为以后的南海自生热带气旋预报工作积累一定经验。 相似文献
13.
Observations of the Labrador Sea eddy field 总被引:2,自引:0,他引:2
Jonathan M. Lilly Peter B. RhinesFriedrich Schott Kara LavenderJohn Lazier Uwe SendEric D’Asaro 《Progress in Oceanography》2003,59(1):75-176
This paper is an observational study of small-scale coherent eddies in the Labrador Sea, a region of dense water formation thought to be of considerable importance to the North Atlantic overturning circulation. Numerical studies of deep convection emphasize coherent eddies as a mechanism for the lateral transport of heat, yet their small size has hindered observational progress. A large part of this paper is therefore devoted to developing new methods for identifying and describing coherent eddies in two observational platforms, current meter moorings and satellite altimetry. Details of the current and water mass structure of individual eddy events, as they are swept past by an advecting flow, can then be extracted from the mooring data. A transition is seen during mid-1997, with long-lived boundary current eddies dominating the central Labrador Sea year-round after this time, and convectively formed eddies similar to those seen in deep convection modeling studies apparent prior to this time. The TOPEX / Poseidon altimeter covers the Labrador Sea with a loose “net” of observations, through which coherent eddies can seem to appear and disappear. By concentrating on locating and describing anomalous events in individual altimeter tracks, a portrait of the spatial and temporal variability of the underlying eddy field can be constructed. The altimeter results reveal an annual “pulsation” of energy and of coherent eddies originating during the late fall at a particular location in the boundary current, pinpointing the time and place of the boundary current-type eddy formation. The interannual variability seen at the mooring is reproduced, but the mooring site is found to be within a localized region of greatly enhanced eddy activity. Notably lacking in both the annual cycle and interannual variability is a clear relationship between the eddies or eddy energy and the intensity of wintertime cooling. These eddy observations, as well as hydrographic evidence, suggest an active role for boundary current dynamics in shaping the energetics and water mass properties of the interior region. 相似文献
14.
Xin Li Dongliang Wang Baoquan Liu Chunling Ren Jianying Guo Xuefeng Su Jian Wang 《中国地球化学学报》2008,27(4):412-419
The northern margin of the Qaidam Basin is one of the main oil-gas exploration areas in western China, where source rocks are composed mostly of Middle and Lower Jurassic dark mud shale, carbargillite and coal. A large number of subsurface and outcrop samples differing in lithology with different types of organic matter were selected for resource evaluation, research and calculation. And among them, 13 samples were used for simulation experiment on hydrocarbon generating potential of various source rocks. At first, two kinds of heating modes were compared through simulation experiment, including single temperature-step heating and continual heating. Perhaps, the process of hydrocarbon generation and expulsion occurred naturally between a close system and an open system. In addition, the first heating mode was convenient, and all its reaction products were involved in the whole thermal evolution, and the final simulation experimental results were basically in consistency with the natural evolution trend Therefore, the first heating mode was adopted and the hydrocarbon yield of every sample was worked out. According to the type and lithology of organic matter and the hydrocarbon yield of samples for simulation experiment, hydrocarbon generation and expulsion mode with three kinds of lithology and five types of source rock has been established to provide the basis for hydrocarbon generation evaluation, research and resource calculation. 相似文献
15.
The 40Ar/39Ar method using a laser probe opened the door to microscale measurements and diffusion profiles frozen in samples. In the first decade since the initial application of a laser for 40Ar/39Ar dating in 1973, practical applications have been few. This is due not only to the fact that the laser and vacuum technologies were immature but that mass spectrometry was also in its infancy. In those days, the sensitivity of a mass spectrometer was generally insufficient to measure the small amount of argon degassed from a geological sample by a laser. These problems have subsequently been solved by new technologies. To understand their current status, a brief history of their development is outlined. This outline focuses on the required detection limit in micro scale measurement, practical approaches for accurate measurement are explained through examples in our laboratory specifically relating to the technical aspects of 40Ar/39Ar dating. 相似文献
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17.
本文以板块绝对运动AM1-2模型为边界条件探讨了不同的瑞利数下地幔热对流模型.结果表明,瑞利数小于10000(529.41)时,地幔对流呈现以板块驱动图式,运动的极型场和环型场由板块运动激发,两种场占有差不多相同的功率.当瑞利数增加到接近或略超过最低临界值时(约1.5倍),对流呈现出复杂状态:1.板块运动速率小于下伏地幔对流速率;2.区域性的双层对流环出现;3.对流谱成分发生变化;4.环型场仅在地幔很浅的区域中起作用,而在地幔深部对流图式中影响很小. 相似文献
18.
大理州2005年初夏出现了严重干旱气象事件.从500pHa高空环流特征、500pHa距平场特征、西太平洋副高特征量及北太平洋中低纬海温距平场、OLR距平场对这次干旱的成因进行了分析,分析结果表明:2005年初夏(4月1日~6月10日)降水异常偏少气温明显偏高是发生干旱的主要原因,高空大气环流异常、西太平洋副高持续偏强偏西、冷空气活动偏北是导致干旱的直接原因;孟加拉湾南部4月OLR场呈明显正距平,抑制低值系统的发展和东北移影响云南,是影响2005年大理初夏干旱重要原因;北太平洋中低纬海温特征与大理州初夏干旱有一定的遥相关性. 相似文献
19.
The relationship between depth, age and gravity in the oceans 总被引:2,自引:0,他引:2
20.