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The creation of a road network can lead to the fragmentation and reduction of the connectivity of the ecological habitat. The study of urban ecological networks under threat from rapidly developing road networks is of great significance in understanding the changes in urban ecological processes and in constructing a reasonable ecological network. Spatial syntax is a linear space analysis method based on graph theory. Taking Wuhan city as an example and adopting spatial syntax to quantify road network threat factors, two resistance surfaces are established based on land use type assignment and overlapping road network threat factor assignment. The ecological environment under two scenarios is constructed by combining the MSPA (Morphological Spatial Pattern Analysis) method and MCR (Minimal Cumulative Resistance) model to comprehensively evaluate the network. Results demonstrate that spatial syntax can effectively describe the spatial characteristics of the road network. The average resistance value of the study area increases by 15.94%, the length of corridor increases by 37.9 km, the energy consumption of biological and material exchanges increases, and the resistance increases. To a certain extent, the model reflects the impact of road network threats on ecological processes. The results are useful in identifying the impact of human activities on ecological processes and provide a reference point for the construction of urban ecological security patterns.

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Precise crystal structure determination of the Halloysite is extremely challenging because Halloysite naturally occurs as small cylinders and the ideal single crystal sample is unavailable. The up-to-date ICSD does not have the cystal structure data of Halloysite. With the development of computer science and technologies, the X-ray powder diffraction technologies have been commonly used in the crystal structure determination. This paper attempts to obtain the refined crystal structure of Halloysite by using the X-ray powder diffraction, on the assumption that the Halloysite and Kaolinite have a similar cystal structure, that is, the 1:1 phyllosilicates structure. The structure refinement program Rietica 2010 is used in this paper.