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G.S.GOLITSYN 《大气科学进展》2009,(3)
The goal of this paper is to quantitatively formulate some necessary conditions for the development of intense atmospheric vortices. Specifically, these criteria are discussed for tropical cyclones (TC) and polar lows (PL) by using bulk formulas for fluxes of momentum, sensible heating, and latent heating between the ocean and the atmosphere. The velocity scale is used in two forms: (1) as expressed through the buoyancy flux b and the Coriolis parameter lc for rotating fluids convection, and (2) as expresse... 相似文献
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本文根据海湾扇贝的肥满度、肉柱百分数、性腺指数及消化脓指数等指标的周年变化,并结合性腺的组织切片来确定其繁殖期。结果表明,海湾扇贝南移后的繁殖期是从每年的10月下旬开始的,直到翌年5月下旬,其中4月为繁殖盛期。繁殖期间,扇贝的性腺分批成熟,分批排放,并有消退与恢复的现象。同时,海湾扇贝引进中国北方海区并南移福建后,其繁殖规律与原产地(美国大西洋沿岸)的繁殖期有很大的不同。 相似文献
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在简介农业地质环境调查和中国农产品认证现状的基础上,论述了农业地质环境调查成果可为无公害农产品、绿色食品和有机食品的产地认证提供有益的补充,特别是在有机食品的产地认证中可发挥独特作用.结合萧山大青梅原产地保护认证的实践,阐明了通过农业地质环境调查建立农作物的原产地地质模型,可为原产地的地域划定提供科学依据,也可为扩大优质农作物的种植面积和调整农业产业结构提供基础资料. 相似文献
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洞庭东山,又称东洞庭山,俗称东山,位于江苏省吴县太湖洞庭山。东山是延伸于太湖中的一个半岛,三面环水,万顷湖光连天,渔帆点点,与洞庭西山、光福邓蔚等72峰交汇而成。洞庭东山既是绮丽宽广的太湖风景区,也是我国四大名茶之一——洞庭碧螺春的产地。东山镇是典型的江南古镇,苏州市旅游名镇。自古以来,它就以其独特的地理位置,秀美的湖光山色,以及众多名胜古迹、珍贵文物,使人流 相似文献
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LIU Jianying LIU Li QU Xiyu .Exploration & Development Research Institute of Daqing Oilfield Company Ltd. Daqing Heilongjiang China .College of Earth Sciences Jilin University Changchun China 《东北亚地学研究》2009,12(1):1-4
Clay minerals in the outcropped sandstone from Lower Cretaceous Chengzihe Formation and Muling Formation in Jixi Basin were analyzed by X-ray diffraction. The results show that the clay minerals mainly consist of illite, kaollinite and illite/smectite, which can be divided into two types: kaolinite- and illite/smectite types. The outcropped sandstone occurred in middle diagenetic stage-A on the basis of the clay mineral composition. The development factor of the formation of kaolinite type clay mineral is caused mainly by the organic acid from the coal-bearing formation and nmdstone during the diagenesis process in Lower Cretaceous Chengzihe Formation and Muling Formation in the Jixi Basin. The weak hydrodynamic force of sedimentary facies made the sandstone leaching condition poor, which is the reason forming the aggregation of clay minerals of the illite/ smectite-and illite types. 相似文献
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Rev I. Gavriliev 《寒旱区科学》2014,6(5):0461-0469
A methodology for calculating the thermal conductivity of soils and rocks is developed which takes into account their origin and mineralogical composition.This method utilizes three approaches.One is founded on the structural modeling of contact heat interaction between particles and fills and estimates the statistical probability distribution of the particles in the volume of the medium.The second approach analyses perturbation to the temperature field of the matrix medium by ellipsoidal inclusions.The third approach is to find the mean thermal conductivity of the solid skeleton in the universal model at different composition of rock-forming minerals. 相似文献
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<正>生物入侵是指一种生物从原产地到另外的一个非原产地的一个地理范围并建立种群,对新分布区生态系统的结构和功能造成明显影响,并造成严重的生态危害和经济损失。 相似文献