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Tourism is a social and economic phenomenon, whose occurrence and development are also based on the spatial system as the material carrier. The spatial structure of tourism not only is the spatial state of tourism activities, but also reflects the spatial attributes and interrelationships of tourism activities. The detailed modeling and analysis of the spatial database in this paper is based on the spatial relational algebra. It formally defines the required spatial operation functions to accurately reflect the relationship between the spatial objects. On this basis, the storage level of the spatial geometric objects is established. The spatial index structure is used to analyze and design the spatial selection and the connection algorithm. In the filtering stage of the spatial connection, the plane scanning method is proposed, and in the refining stage, two heuristic strategies are proposed. Apply the above modeling and analysis method to the practice of the spatial distribution of tourism resources in Xi’an, abstract the application domains, extract the spatial geometric elements, and form the conceptual model.

Background Cyperus esculentus oil is also known as the new health care oil. This study aimed to analyse the fatty acid profile and content of C. esculentus oil by gas chromatography–mass spectrometry and to assess the antioxidant activity of C. esculentus oil. These properties were evaluated based on the reducing power, hydroxyl radical and diphenyl picryl hydrazyl radical scavenging, and a combination of in vitro and in vivo antioxidant experiments. Results Composition analyses showed that C. esculentus oil contained more than 800 g kg−1 unsaturated fatty acid, of which oleic acid accounted for 691.4 g kg−1, linoleic acid accounted for 107.0 g kg−1 and palmitic acid accounted for 158.0 g kg−1. In vitro results showed that the total antioxidant activity and the scavenging capacity of hydroxyl radicals and diphenyl picryl hydrazyl radicals increased with increasing concentration. The in vitro antioxidant ability increased as the concentration of C. esculentus oil, with 15 mL kg−1 BW day−1 being established as the optimal dose. Conclusion Taken together, the results of this study clearly indicate that C. esculentus oil has good antioxidant properties. © 2012 Society of Chemical Industry

The chemical composition, morphological characteristics, and pasting properties of Cyperus esculentus starch (CES) grown in Xinjiang, China, were investigated and compared with those of potato starch (PS). The amylopectin (AP) content in CES was measured as of 83.82%. Most of the starch granules of Cyperus esculentus (CE) were round or elliptical while the granule diameter ranged from 3.41 to 12.12 µm with an average value of 8.60 µm, and had a typical polarization cross. The X‐ray diffraction (XRD) data showed that CES was of A‐type crystals. The peak viscosity value of CES paste was much lower than that of PS, and the freeze–thaw stability of CES paste was slightly higher than that of PS, but its light transmittance was lower.

By using a KNO 3 -aging ferrous hydroxide gel method, Fe 3 O 4 particles with sizes ranging from 35 to 1500 nm were synthesized. The particles were covered with a silica coating to form Fe 3 O 4 –SiO 2 core-shell structures by using the improved conventional Stober polycondensation method. The thickness of the SiO 2 covering on magnetite particles surface varies from 10 to 20 nm. The morphology, size and composition of the particles were determined by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The particles with and without coating with SiO 2 were pressed into slices with an oil press at 10 MPa. Subsequently, the coercive forces H C of the particles were measured by VSM at room temperature, and the critical size for a single domain was estimated. The shape of the particles is basically spherical when the size is smaller than 800 nm, while it is hexagonal for larger particles. The H C of Fe 3 O 4 –SiO 2 core-shell structure was larger than that of the uncoated Fe 3 O 4 particles by 20%, which was explained to be due to the reduction of inter-particle magnetostatic interaction, supported by an agreement with the packing factor. The dependence of H C on magnetic particle size could be explained and fitted by the Heewell–Knozam stacking density equation and object-oriented micromagnetic computing framework (OOMMF) micromagnetic software. the results agree well with the experimental data.

Cyperus esculentus oil is also known as the new health care oil. This study aimed to analyse the fatty acid profile and content of C. esculentus oil by gas chromatography-mass spectrometry and to assess the antioxidant activity of C. esculentus oil. These properties were evaluated based on the reducing power, hydroxyl radical and diphenyl picryl hydrazyl radical scavenging, and a combination of in vitro and in vivo antioxidant experiments.Composition analyses showed that C. esculentus oil contained more than 800 g kg(-1) unsaturated fatty acid, of which oleic acid accounted for 691.4 g kg(-1), linoleic acid accounted for 107.0 g kg(-1) and palmitic acid accounted for 158.0 g kg(-1). In vitro results showed that the total antioxidant activity and the scavenging capacity of hydroxyl radicals and diphenyl picryl hydrazyl radicals increased with increasing concentration. The in vitro antioxidant ability increased as the concentration of C. esculentus oil, with 15 mL kg(-1) BW day(-1) being established as the optimal dose.Taken together, the results of this study clearly indicate that C. esculentus oil has good antioxidant properties.

The limited information on the genetic differences among the 15 currently known serotypes of Actinobacillus pleuropneumoniae has significantly hampered the development of typing-based diagnostic methods and multivalent vaccines. In this study, we compared the genomic differences between A. pleuropneumoniae strains CVCC259 (serotype 1) and CVCC261 (serotype 3) by representational difference analysis. Of the eight differential DNA sequences in the CVCC259 strain and 11 differential DNA sequences in the CVCC261 strain that we identified, seven represent known virulent genes, 10 encode putative proteins, and two encode hypothetical proteins. We also investigated the distribution of these 19 sequences among the 15 serotypes, and each serotype showed a different distribution pattern. The autotransporter adhesin occurred as a novel putative virulence factor in serotypes 1, 5, 7, 8, 9, and 11. Notably, the presence of wzm and wzt in serotypes 1, 9, and 11 and the diverse distribution of wzz and wzy in the other serotypes suggest the presence of different O-antigen biosynthesis pathways among serotypes. The information on the differential distribution of these DNA sequences in the 15 serotypes of A. pleuropneumoniae may contribute to future research on the pathogenic mechanisms of different serotypes, typing-based diagnosis methods, and multivalent vaccines.

A series of Co1−xZnxFe2O4 particulate nano-ferrites with x = 0, 0.2, 0.4, 0.5, 0.6, 0.7, and 0.8, fabricated by the co-precipitation method, have been investigated. The lattice parameter is found to increase and particle size decreases with increasing x. Mossbauer spectroscopy at room temperature exhibits ferromagnetic hyperfine splitting sextet peaks with a doublet peak overlapping at its center as Zn contents x