394 research outputs found
Building Vulnerability to Landslides: Broad-Scale Assessment in Xinxing County, China
No full textThis study develops a model to assess building vulnerability across Xinxing County by integrating quantitative derivation with machine learning techniques. Building vulnerability is characterized as a function of landslide hazard risk and building resistance, wherein landslide hazard risk is derived using CNN (1D) for nine hazard-causing factors (elevation, slope, slope shape, geotechnical body type, geological structure, vegetation cover, watershed, and land-use type) and landslide sites; building resistance is determined through quantitative derivation. After evaluating the building susceptibility of all the structures, the susceptibility of each village is then calculated through subvillage statistics, which are aimed at identifying the specific needs of each area. Simultaneously, different landslide hazard classes are categorized, and an analysis of the correlation between building resistance and susceptibility reveals that building susceptibility exhibits a positive correlation with landslide hazard and a negative correlation with building resistance. Following a comprehensive assessment of building susceptibility in Xinxing County, a sample encompassing different landslide intensity areas and susceptibility classes of buildings was chosen for on-site validation, thus yielding an accuracy rate of the results as high as 94.5%
Invariant Distributionally Scrambled Manifolds for an Annihilation Operator
No full textThis note proves that the annihilation operator of a quantum harmonic oscillator admits an invariant distributionally ε-scrambled linear manifold for any 0<ε<2. This is a positive answer to Question 1 by Wu and Chen (2013)
Revisiting type-2 triangular norms on normal and convex fuzzy truth values
No full textThis paper studies t-norms on the space of all normal and convex
fuzzy truth values. We first prove that the only non-convolution form type-2
t-norm constructed by Wu et al. satisfies the distributivity law for
meet-convolution and show that t-norm in the sense of Walker and Walker is
strictly stronger than t-norm on , which is strictly stronger
than t-norm on . Furthermore, we characterize some restrictive
axioms of t-norms for convolution operations on and obtain
some necessary conditions for t-(co)norm convolution operations on
.Comment: arXiv admin note: text overlap with arXiv:1908.10532,
arXiv:1907.1239
Incorporating High-Speed Rail Development Scenario for Tourism Land Use Simulation: A Case Study of Xinxing County, China
No full textHigh-speed rail (HSR) has been proven to drive the development of regional tourism. However, few studies paid attention to the impact of HSR on future tourism land use. In this study, points of interest (POI) were used to obtain the locations and types of tourism facilities, and high-resolution remote sensing images helped us determine the spatial extents of the tourism facilities, so that tourism land could be identified. A system dynamics (SD) model was coupled with the patch-generating land use simulation (PLUS) model to simulate future tourism land by considering two scenarios, including HSR-led development (HRD) and the historical development pattern (HD) scenario. The SD model was employed to project the amount of tourism land and determine the HSR effects via empirical analysis. The PLUS model was applied to simulate the spatial distribution of tourism land and model the HSR effect by adopting a planned tourism area as the development area. The study area is Xinxing County in Guangdong Province, China, a county dominated by rural tourism, with the HSR expected to open in 2025. The results revealed that the SD-PLUS model has great advantages in simulating tourism land use change, and the HRD scenario leads to major changes in the sources of tourism land growth. This research provides new insights for policymakers on making countermeasures for the sustainability of tourism and rural revitalization at the county level
Recent progress in the use of graphene/polymer composites to remove oil contaminants from water
No full textFrequent oil spill accidents and the massive discharge of industrial oily sewage have destroyed the ecological balance and threatened marine life. Graphene (G) and graphene oxide (GO) have emerged as important materials in the field of oil/water separation because of their remarkable physicochemical properties including high specific surface area, low density, high porosity and tailorable surface functionality. To take full advantage of G and GO, their incorporation with polymers to build functional G/polymer and GO/polymer composites has recently gained increasing popularity because of their improved oil clean-up capability, outstanding mechanical performance, relatively low cost and adjustable surface chemical composition. Tremendous efforts have contributed to the development of G/polymer and GO/polymer composite oil clean-up sorbents and filtration membranes in 3D structural forms such as aerogels, foams, sponges and membranes. In this review, a comprehensive picture from the basic theory of the surface wettability to the recent advances in G/polymer and GO/polymer composite oil clean-up sorbents and filtration membranes are highlighted. The strategies for oil recovery and regeneration of the sorbents are also summarized. Current challenges and future research directions in this topic are provided, aimed at providing new perspectives for in-depth exploration in this field.</p
Multi-Scenario Simulation of Land-Use Change and Delineation of Urban Growth Boundaries in County Area: A Case Study of Xinxing County, Guangdong Province
No full textDelineating urban growth boundaries (UGBs) by combining the land-use/land-cover (LULC) change simulation method has become common in recent studies. However, few of the existing studies have integrated multi-source big data to analyze the driving factors of LULC dynamics in the simulation. Moreover, most of previous studies mainly focused on the UGBs delineation in macroscale areas rather than small-scale areas, such as the county area. In this study, taking Xinxing County of Guangdong Province as the study area, we coupled a system dynamics (SD) model and a patch-generating land-use simulation (PLUS) model to propose a framework for the LULC change simulation and UGBs delineation in the county area. Multi-source big data such as points of interest (POIs), night-time light (NTL) data and Tencent user density (TUD) were integrated to analyze the driving forces of LULC change. The validation results indicate that the coupled model received high accuracy both in the land-use demand projection and LULC distribution simulation. The combination of multi-source big data can effectively describe the influence of human socio-economic factors on the expansion of urban land and industrial land. The UGBs delineation results have similar spatial patterns with the LULC change simulation results, which indicates that the proposed UGBs delineation method can effectively transform the LULC simulation results into available UGBs for the county area. It has been proven that the proposed framework in this study is effective for the LULC change simulation and UGBs delineation in the county area, which can provide insight on territorial spatial planning in the county area
A Remark on Topological Sequence Entropy
No full textLet [Formula: see text] be the supremum of all topological sequence entropies of a dynamical system [Formula: see text]. This paper obtains the iteration invariance and commutativity of [Formula: see text] and proves that if [Formula: see text] is a multisensitive transformation defined on a locally connected space, then [Formula: see text]. As an application, it is shown that a Cournot map is Li–Yorke chaotic if and only if its topological sequence entropy relative to a suitable sequence is positive.</jats:p
The synthesis of triazole compounds via visible light-mediated organic photosensitizer catalysis
No full textPhotoinduced reactions, combined with organometallic catalysis, small molecule catalysis, and asymmetric catalysis, have achieved many structurally complex heterocyclic compounds and natural organic compounds, enriching,and developing the research content of organic reaction methodology. Among numerous heterocyclic compounds, triazole is an important class of five membered heterocyclic compounds with biological and pharmacological activities,widely used in pharmaceuticals, pesticides, and other fine chemical fields. Based on this, this study synthesized a series of 1,4,5-substituted 1,2,3-triazole compounds by [3+2] cycloaddition under visible light mediation, using azide and benzoylacetonitrile as raw materials and pyrene as organic photocatalysts, and the corresponding target compounds were characterized using data such as nuclear magnetic resonance H-spectroscopy, C-spectroscopy, high-resolution mass spectrometry and melting point. The experimental results show that the reaction conditions are mild, the regioselectivity is high and the functional group compatibility is good. In addition, the reaction operation is simple, the yield is as high as 99%, and the reaction mechanism reveals the potential reaction course of this photoconversion. This study provides a simple, efficient, and green method for the synthesis of 1,2,3-triazole derivatives, simultaneously enriching the molecular library of triazole heterocyclic compounds
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