Analysis of the spatial differentiation and scale effects of the three-dimensional architectural landscape in Xi'an, China.

Three-dimensional landscape patterns are an effective means to study the relationship between landscape pattern evolution and eco-environmental effects. This paper selects six districts in Xi'an as the study area to examine the spatial distribution characteristics of the three-dimensional architectural landscape in the city's main urban area using three-dimensional information on the buildings in 2020 with the support of GIS. In this study, two new architectural landscape indices-landscape height variable coefficient and building rugosity index-were employed in landscape pattern analysis, whilst a system of rigorous and comprehensive three-dimensional architectural landscape metrics was established using principal component analysis. A mathematical model of weighted change of landscape metrics based on the objective weighting method was applied to carry out scale analysis of the landscape patterns. Spatial statistical analysis and spatial autocorrelation analysis were conducted to comprehensively study the differentiation of three-dimensional architectural landscape spatial patterns. The results show that the characteristic scale of the three-dimensional landscape pattern in Xi'an's main urban area is around 8 km. Moreover, the three-dimensional landscape of the buildings in this area is spatially positively correlated, exhibiting a high degree of spatial autocorrelation whilst only showing small spatial differences. The layout of the architectural landscape pattern is disorderly and chaotic within the second ring, whilst the clustering of patch types occurs near the third ring. Moreover, the building density in the Beilin, Lianhu, and Xincheng districts is large, the building height types are rich, and the roughness of the underlying surface is high, such that these are key areas to be improved through urban renewal. The height, volume, density, morphological heterogeneity, and vertical roughness of the architectural landscape vary amongst functional areas within the study area. This paper is the first to apply the study of spatial heterogeneity of three-dimensional landscape patterns to Xi'an. It does so in order to provide a quantitative basis for urban landscape ecological design for urban renewal and the rational planning of built-up areas, which will promote the sustainable development of the city's urban environment.

Construction of Prescription Database of The Four Medical Tantras and Analysis of Its Medication Rules Based on Complex Network Analysis and Visual FoxPro / 中国实验方剂学杂志

Objective: The Four Medical Tantras is a classic work of Tibetan medicine, in which drug treatment is one of the four main treatment methods, and prescriptions are the main form of clinical drug use. The study on the medication rules of The Four Medical Tantras has positive significance for the clinical medication research of Tibetan medicine. Method: Prescriptions recorded in Secret Medical Code and Follow-up Medical Code from The Four Medical Tantras were collected, the prescription database was constructed by Visual FoxPro 9.0, combined the dual perspectives of the " fifteen categories" (skabs bco lnga) of Tibetan medical diseases and the " eighteen practices" (lag len bco brgyad) of treatment, and Gephi 0.9.2 complex network was used to analyze its medication rules. Result: The Four Medical Tantras contained 2 695 Tibetan medicine prescriptions, average number of drugs in each prescription was 6.6, prescription composed of ≤ 7 drugs accounted for 69.2%of the total prescription. There were 1 002 kinds of medicines involved in the total prescription, of which 156 was the nodal degrees of Chebulae Fructus, Bambusae Concretio Silicea, Carthami Flos, Piperis Longi Fructus and Zingiberis Rhizoma and so on; followed by 91 nodal degrees of butter (mar), sugar, barley sweetener (sbang ma), honey and brown sugar and so on, which were Tibetan medicinal and edible medicines. According to the classification of diseases in the fifteen categories, there were 495 prescriptions for traumatology (mtshon rma), 323 for fever (tsha ba), 278 for toxics and 197 for three factors diseases. According to the treatment method of eighteen practices, 162 powder, 77 decoction, 84 laxative (bxhal) and others were used. Association rule analysis found that edge weights of Borneolum Syntheticum, Bambusae Concretio Silicea, Carthami Flos, Santali Albi Lignum and other cold medicines were 59, edge weights of pomegranate seeds, Piperis Longi Fructus, Cinnamomi Cortex, Amomi Fructus Rotundus and other warm medicines were 45. Conclusion: The Four Medical Tantras has some characteristics, including the medication rules of elliptic philosophy with cool-warm medicinal properties as the dual core, elimination-diarrhea (zhi-sbyong) as medication methods, weight of rlung-mkhris pa-bad kan as medication dialectical thinking and so on. Among them, the clinical application of butter, barley sweetener, sugar and other special delivery agents of Tibetan medicine is prominent. The prominent clinical application of special Tibetan medicines embodies the philosophy of Tibetan culture with the emphasis on overall balance. It has the multi-dimensional medication rule of " diet plus medicine, medicine plus therapy", and has positive significance for revealing the research on medication rules of Tibetan medicine.