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排序方式: 共有350条查询结果,搜索用时 15 毫秒
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In this article,the backstripping technique was used in studying the subsidence charac-ters of the Qiongdongnan(琼东南) basin(QDNB) in order to understand its dynamic mechanism of formation and evolution.Meanwhile,the geothermal characteristics of this area were summarized,and the stretching factors(β) of the upper crust,the whole crust,and the whole lithosphere were calculated.The QDNB is characterized by high subsidence rate,high geothermal gradient,high geothermal heat flow,and the lithosphere stretching an... 相似文献
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Application of stable isotope techniques in studies of carbon and nitrogen biogeochemical cycles of ecosystem 总被引:1,自引:1,他引:0
Zhigao Sun Xiaojie Mou Xinhua Li Lingling Wang Hongli Song Huanhuan Jiang 《中国地理科学(英文版)》2011,21(2):129-148
Stable isotope techniques have been proved useful as tools for studying the carbon (C) and nitrogen (N) biogeochemical cycles of ecosystem. This paper firstly introduced the basic principles and the distribution characteristics of stable isotope, then reviewed the recent advances and applications of stable isotope in the C and N biogeochemical cycles of ecosystem. By applying the 13 C natural abundance technique, ecologists are able to understand the photosynthetic path and CO 2 fixation of plants, the CO 2 exchange and C balance status of ecosystem, the composition, distribution and turnover of soil organic C and the sources of organic matter in food webs, while by using the 13 C labeled technique, the effects of elevated CO 2 on the C processes of ecosystem and the sources and fate of organic matter in ecosystem can be revealed in detail. Differently, by applying the 15 N natural abundance technique, ecologists are able to analyze the biological N 2 -fixation, the N sources of ecosystem, the N transformation processes of ecosystem and the N trophic status in food webs, while by using the 15 N labeled technique, the sources, transformation and fate of N in ecosystem and the effects of N input on the ecosystem can be investigated in depth. The applications of both C and N isotope natural abundance and labeled techniques, combined with the elemental, other isotope ( 34 S) and molecular biomarker information, will be more propitious to the investigation of C and N cycle mechanisms. Finally, this paper concluded the problems existed in current researches, and put forward the perspective of stable isotope techniques in the studies on C and N biogeochemical cycles of ecosystem in the future. 相似文献
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Phosphorus biological cycle in the different Suaeda salsa marshes of the Yellow River estuary, China
Zhigao Sun Xiaojie Mou Hanqin Tian Hongli Song Huanhuan Jiang Jinyong Zhao Wanlong Sun Wenguang Sun 《Environmental Earth Sciences》2013,69(8):2595-2608
Much uncertainty exists in the phosphorus (P) cycle in the marshes of the intertidal zone. This study explored the P cycling in the two Suaeda salsa marshes [middle S. salsa marsh (MSM) and low S. salsa marsh (LSM)] of the Yellow River estuary during April 2008 to November 2009. Results showed seasonal fluctuations and vertical distributions of P in different S. salsa marsh soils, and variations in P content in different parts of plants due to water and salinity status. The N/P ratios of the different S. salsa were 9.87 ± 1.23 and 15.73 ± 1.77, respectively, indicating that plant growth in MSM was limited by N, while that in LSM was limited by both N and P. The S. salsa litter in MSM released P to the environment throughout the year, while that in LSM immobilized P from the environment at all times. The P absorption coefficients of S. salsa in MSM and LSM were very low (0.0010 and 0.0001, respectively), while the biological cycle coefficients were high (0.739 and 0.812, respectively). The P turnovers among compartments of MSM and LSM showed that the uptake amounts of roots were 0.4275 and 0.0469 g m?2 year?1 and the values of aboveground parts were 1.1702 and 0.1833 g m?2 year?1, the re-translocation quantities from aboveground parts to roots were 0.8544 and 0.1452 g m?2 year?1, the translocation amounts from roots to soil were 0.0137 and 0.0012 g m?2 year?1, the translocation quantities from aboveground living bodies to litter were 0.3157 and 0.0381 g m?2 year?1, and the annual return quantities from litter to soil were less than 0.0626 and ?0.0728 g m?2 year?1 (minus represented immobilization), respectively. P was an important limiting factor in S. salsa marshes, especially in LSM. S. salsa was seemingly well adapted to the low-nutrient condition and the vulnerable habitat, and the nutrient enrichment due to the import of N and P from the Yellow River estuary would be a potential threat to the S. salsa marshes. 相似文献
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在Au(Ⅲ)-Cl络合溶液和常温常压条件下,黄铁矿随时间(t)变化对金吸附的动态实验表明:整个吸附过程明显分为两个阶段.前一个阶段是快速达到平衡的吸附过程,随着平衡的建立,金的沉淀速度迅速变小,随后即进入缓慢吸附阶段,溶液中金的浓度按指数函数关系衰减.不同粒度黄铁矿实验结果的横向比较显示,粒度越细,金的沉淀速度越快,沉淀金的总量也越多。 相似文献
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煤层气藏的储集特征及储层评价 总被引:1,自引:0,他引:1
论述了煤层气非常规天然气的特征,指出控制煤储集性能的因素主要是煤岩性质、煤层埋藏深度及地质构造条件等,并综合分析了煤层气储层各种评价参数,指出各种有利于煤层气藏的地质条件和物性条件。 相似文献
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通过对含金石英脉中矿物包裹体的研究,探讨了文峪金矿形成的物理化学条件,指出文峪金矿是在地表较浅部位形成的中-低温热液型矿床,其成矿母液为低盐度Na-Ca-Cl-CO2系列热液流体。运用了包体测温和包体化学成分以及盐度、密度等资料,对该矿进行了深部成矿预测,认为文峪金矿深部有宫金矿体存在,具有广阔的找矿勘探前景。 相似文献