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全球矿产资源时空分布的不均匀性及其形成机制,已成为地球科学关注的热点和前沿领域。本文在对全球矿产资源的空间分布规律及其不均匀性分布特点的研究进展进行全面阐述的基础上,重点分析了控制成矿作用空间分布不均匀性的主要因素,如地壳组成与演化的差异、地壳/地幔化学组成的不均一性、成矿构造环境的差异、重大地质构造事件的影响、构造转换或转折和叠加、矿床形成与保存能力等。研究认为,深刻理解全球矿产资源空间分布的不均匀性特征及其形成的根本原因,应加强以下五个方面的研究:①大陆成矿作用的空间分布不均匀性的机制;②从全球构造角度,揭示成矿作用的时空分布规律;③强调深部成矿过程,以阐明成矿作用不均匀性原因;④加强成矿系统、成矿系列研究;⑤加强矿产资源时空分布不均匀性的形成机制研究。 相似文献
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研究观察了苗种生产过程中亲蜇产卵间隙卵巢中的卵子、自然产卵排放的卵子、受精卵的差异,结果发现其卵径依次增大,平均值依次为(74.57±1.05)、(84.22±1.13)、(92.03±1.39)μm,且非产卵时刻其卵巢中的卵子不具有受精能力,海蜇自然排放的卵子2h后亦失去受精能力。该结果表明,海蜇卵子产卵排放前须经历必要的生理转化过程才能成熟排放,具有受精能力。海蜇卵子受精后半径增大,表明海蜇卵子受精过程中亦会发生皮层反应,具体过程与机制需要进一步的研究。本文研究表明,海蜇人工授精不是可以随意进行的,应选择在海蜇自然产卵排精前后的时机及时进行。 相似文献
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WANG Maoqiu HU Yang HE Ning WU Mingxuan WU Pengling WANG Qinyi ZHANG Bolun ZHANG Shengle GAO Meihua FANG Shubo 《资源与生态学报(英文版)》2022,13(6):1152-1164
This study examines how the spatiotemporal patterns of functional groups of macro benthos responded to coastal wetland restoration projects. Compared with the traditional single-species approach, methods for identifying functional groups of macro benthos more comprehensively reflect the states of the wetland, i.e., spatiotemporal patterns and the related influencing factors. In this study, the macro benthos samples, soil samples, and plant samples were collected at each same sample site in April, July, and October of 2017 and January of 2018. After classification of the macro benthos functional groups according to some traits, the factors influencing the functional groups were examined by a linear stepwise regression. The results showed that all macro benthos were classified into 11 different functional groups based on their traits of forms of locomotion, feeding habits, and food gathering methods. The semi-mobile suspensivores (FDX), semi-mobile surface detritivores (SDX), and Jawed mobile carnivores (CMJ) were the main groups observed in a year. Regression analysis showed that particle size, moisture content, and plant height were important common factors influencing most groups. The main influencing factor of FDX was particle size (P=0.020). Moisture content (P=0.004), plant cover degree (P=0.008), and particle size (P=0.032) comprised the main restrictions of SDX in summer. Soil salinity (P=0.040) and plant height (P=0.011) were the factors influencing CMJ in autumn and winter. This study shows the changing characteristics of macro benthos functional groups to promote coastal wetland restoration and future biogeomorphological studies. 相似文献
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Li Xia Liu Zhenhai Wang Shaoqiang Li Fengting Li Hui Zhu Tongtong Qian Zhaohui Tu Yongkai Liu Yuanyuan Wang Xiaobo Wang Qinyi Shi Weibo Li Donghui 《地理学报(英文版)》2022,32(9):1831-1846
Journal of Geographical Sciences - In tropical regions, mangrove forests are located in the inter-tidal areas between land and sea, and are at risk from both freshwater and seawater floods. Using... 相似文献
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