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碳氮稳定同位素比值在潮间带大型底栖动物组织间差异性研究 总被引:1,自引:1,他引:0
近年来,稳定同位素技术已被广泛应用于食物网研究中。然而,生物样品取样部位对食物网构建的影响的研究相对少见。大型底栖动物作为潮间带食物网的重要组成部分,在食物网研究中有必要对其采样部位进行统一,以增加研究结果的准确性及可比较性。本研究选取黄河三角洲和烟台潮间带10种代表性的大型底栖动物,比较δ13C和δ15N在不同采样部位中的差异。结果显示,对于大多数底栖动物而言,采样部位将直接影响到δ13C和δ15N的测定结果。当底栖动物作为摄食者,需分析其食性和营养级时,应统一采用肌肉组织,如贝类的闭壳肌或足部肌肉,蟹类的鳌足肌肉,鱼类的背部肌肉;当底栖动物作为被摄食者,需分析次级消费者的食性和营养级时,除多毛类采用去除消化道内容物的体壁外,其他种类应选取整体(难以被消化的组织除外),如贝类的软体部,蟹类肌肉与鳃等的混合组织。 相似文献
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西湖凹陷于胡组地层沉积于海陆过渡相背景。本文侧重分析平湖组地层中出现的半咸水有孔虫群的若干特征,讨论了半咸水有孔虫群的生态环境。根据古生物组台的变化,提出了平湖组沉积环境演化的三个发展阶段。 相似文献
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东海西湖凹陷始新统平湖组沉积层序特征及控相机制讨论 总被引:4,自引:0,他引:4
西湖凹陷平湖组(E_2~(2-3)系海陆过渡相沉积。海平面升降变化控制了不同成因类型砂体的空间展布。在钻井剖面上,可识别多种沉积层序。作者从岩心、测井、古生物诸方面分析了各种沉积层序的形成过程,揭示了海平面升降对沉积过程的控制作用。 相似文献
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The rapid progress of China's industrialization has been manifested in space as the formation and evolution of a series of industrial bases. Employing data from the years 1985, 2001 and 2010, this paper carries out differentiation, screening, and categorization of industrial bases in China. It then analyses the evolutional characteristics of these industrial bases and explores different paths of growth according to their scale or types, and summarizes the general pattern for their formation and evolution. The results of this study indicate that China's industrial bases as a whole have gone through three spatial stages since the founding of the PRC in 1949: decentralized development before reform and opening up in 1978, gradual concentration in eastern coastal regions during the early period of reform and opening up, and balanced and diversified development since the beginning of the 21 st century. By 2010, China had a total of 251 industrial bases and had thereby established the overall spatial map of its industrialization. As industrial bases expand in scale, their industrial structures develop from homogenization to diversification, and then again from diversification to competitive optimization. Leading industries in the vast majority of industrial bases constantly evolve along the track of light industries, basic materials industries, and advanced manufacturing industries. Meanwhile, the key factors in their evolution and development transition from traditional factors of production like resources and labor to new ones like capital and information, but there are significant differences in terms of influencing factors and growth paths between large, medium, and small bases. Small industrial bases primarily rely on natural resources to maintain development through a single leading industry, medium industrial bases gradually become more comprehensive in their industrial compositions, and large industrial bases evolve in the direction of a combination of basic materials industries and equipment manufacturing industries. 相似文献
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根据资源评价和勘探思路中的不确定因素,对资源评价成果与勘探思路形成中所包含的模糊特性,从自然科学与社会科学的交叉、综合点,模糊思维对资源评价研究与勘探决策的影响,进行了探讨,以期在资源评价成果的认识和勘探决策过程中给予充分考虑。 相似文献
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海上石油国际合作项目的风险评价特点分析 总被引:2,自引:0,他引:2
如何进行海上石油国际合作是今后我国3大石油公司在国际能源合作市场中经常面临的问题,如何看待海上石油国际合作项目中的各种风险因素是进行项目经济评价中最复杂的问题。从海外海上油气田勘探开发的经验教训中探讨了地质风险、技术风险、经济风险、政治风险诸因素对项目经济评价的影响。 相似文献
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