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应用X衍射、化学分析结果和物理化学分析方法,研究富钾粗面岩在不同温度下焙烧所发生的矿物成分和结构变化及其变化机理。富钾粗面岩中钾长石向白榴石的转化率在1100℃以前主要受焙烧温度控制,在1100℃以后则受其后的降温速度控制。钾在不同温度焙烧样料中的活性与其中肥料矿物的含量呈正相关。 相似文献
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Since 1999, large-scale ecosystem restoration has been implemented in the Loess Plateau, effectively increasing regional vegetation coverage. Vegetation restoration has significantly elevated the saturated hydraulic conductivity (Ks) of the near-surface soil layers and increased the vertical heterogeneity of the Ks profile. Many studies have examined the change of runoff due to revegetation, yet the impacts of Ks profile on the soil moisture distribution and runoff generation processes were less explored. In this study, numerical simulations were conducted to investigate how changes in the Ks profile caused by vegetation restoration influenced the hydrological responses at event scale. The numerical simulation results show that the increase of surface Ks caused by vegetation restoration can effectively reduce runoff at event scale. Moreover, the enhancement of vertical heterogeneity of Ks profiles can significantly change the vertical profile of soil water content, prompting more water to percolate into the deep soil layer. When rainfall exceeds a threshold, the accumulation of soil water above the relatively less permeable layer can cause short-term saturation in shallow soil layers, resulting in a transient perched water table. As a result, after the vegetation restoration in the Loess Plateau, though Horton overland flow is still the main runoff generation mechanism, there is a possibility of the emergence of Dunne overland flow under the high vegetation coverage (e.g., NDVI larger than 0.5). This emergence of new runoff generation mechanism, saturation excess runoff, in the Loess Plateau due to the vegetation restoration could provide scientific guidance for water and sediment movement, soil and water conservation practices, and desertification control in the Loess Plateau. 相似文献
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简述滑坡的观测方法和滑坡预报 总被引:5,自引:0,他引:5
本文阐述了滑坡观测和滑坡预报的意义和方法,详细地描述了滑坡观测的步骤和工作内容,在此基础之上提出了三种量化的公式预报方法,同时也给出了经验的宏观预报方法。文章表明滑坡的微观观测与经验上的宏观观察相结合是预报滑坡的有效手段。 相似文献
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Wave-Current Propagation over a Frictional Topography 总被引:1,自引:0,他引:1
ZUO Qihua DING Bingcan Prof. Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute 《中国海洋工程》1998,(4)
—In this paper the parabolic approximation model based on mild-slope equation is used tostudy wave propagation over a slowly varying and frictional topography under wave-current interaction.A governing equation considering the friction effects is derived by the authors for the first time.A simpli-fied form for the rate of wave energy dissipation is presented on the basis of the wave-current action conser-vation equation and the bottom friction model given by Yoo and O'connor(1987).Examples reveal thatthe present computational method can be used for the calculation of wave elements for actual engineeringprojects with large water areas. 相似文献
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Renguang Zuo Frederik P. Agterberg Qiuming Cheng Lingqing Yao 《International Journal of Applied Earth Observation and Geoinformation》2009
Geological point processes can be used to model point patterns occurring frequently in a wide variety of geoscience fields, including the study of mineral deposits, oil producing wells, earthquakes, and landslides. Characterization of the spatial distribution of GPP has implications for understanding the properties of the underlying geological processes and events. Three examples of GPP dealing with (1) metallic mineral deposits, (2) oil producing wells, and (3) aftershocks of the Wenchuan earthquake (on 12 May 2008, magnitude 8.0) are presented to illustrate that (1) the spatial distribution of geological point processes generally shows clustering implying rejection of the Poisson model because L(r) > LPois(r); (2) the clustering statistics of the underlying geological processes are fractal; and (3) the size distribution of geological point processes is scale invariant. These results indicate existence of a fundamental law concerning the fractal nature of the point distributions generated by geological point processes. 相似文献