To enhance the gasoline octane number, low-octane linear n-alkanes should be converted into their high-octane di-branched isomers via n-alkane hydroisomerization. Therefore, hierarchical SAPO-11-based catalysts are prepared by adding different contents of sodium dodecylbenzene sulfonate (SDBS), and they are applied in n-nonane hydroisomerization. When n(SDBS)/n(SiO2) is less than or equal to 0.125, the synthesized hierarchical molecular sieves are all pure SAPO-11, and as the SDBS content increases, the submicron particle size decreases, and the external surface area (ESA) increases. Additionally, these hierarchical SAPO-11 have smaller submicron particles and higher ESA values than conventional SAPO-11. When n(SDBS)/n(SiO2) is greater than 0.125, with increasing SDBS content (n(SDBS)/n(SiO2) = 0.25), the synthesized SAPO-11 contains amorphous materials, which leads to a decline in the ESA; with the further increase in SDBS content (n(SDBS)/n(SiO2) = 0.5), the products are all amorphous materials. These results indicate that in the case of n(SDBS)/n(SiO2) = 0.125, the synthesized SAPO-11 molecular sieve (S–S3) has the most external Brønsted acid centers and the highest ESA of these SAPO-11, and these advantages favor generation of the di-branched isomers in hydrocarbon hydroisomerization. Among these Pt/SAPO-11 catalysts, Pt/S–S3 displays the highest selectivity to entire isomers (83.4%), the highest selectivity to di-branched isomers (28.1%) and the minimum hydrocracking selectivity (15.7%) in n-nonane hydroisomerization.

No abstract

No abstract

A new orchid species, Hemipilia avisoides, is described from Songpan County, Sichuan Province, China. Morphologically, it is most similar to H. occidensichuanensis (≡ Ponerorchis limprichtii), but H. avisoides can be easily distinguished by its pendulous lateral lip lobes, the oblong middle lip lobe that is smaller than lateral lobes, the dorsal sepal that is concave at each side of central vein below middle, floral bracts that are always shorter than ovary, the leaf that is appressed to substrate and is adaxially green with white and parallel veins, and the solitary sheath at the base of stem. Floral morphology of H. avisoides is also presented by utilizing in vivo micro-CT scanning and 3D visualization.

detailed analyses of specific taxonomic groups at finer geographic scales to identify and prioritize biodiversity hotspots is a prominent method for optimizing conservation efforts, especially for the uneven species richness. The ecological suitability prediction and analysis of representative species provide vital references for conservation planning. Yet, in predicting suitability for multi-species or groups by species distribution models (SDMs) under a highly heterogeneous environment, species bias may occur cause of the unequal protection status and the spatial autocorrelation processing of occurrence data. For this, diversity, and protection hotspots were mapped in the south of the Hengduan Mountains, a significant site for global biodiversity. Specifically, creating a network of 1 km2 grid cells spanning the region, counting the orchid species, quantifying the protection value, and classifying attributes by the Jenks. And 5 km and 10 m buffer zone for each grid containing attributes compose the diversity and protection hotspot layers and were compared with the orchid suitability map modeled by SDMs. Results showed that even though there were extensively suitable habitats for orchids, the model results cannot completely cover whole the diversity and protection hotspots at any scale. Based on the map attributes, multi-scenario conservation planning was proposed. This study identifies the critical areas of suitability, diversity, and protection of orchids in this region, providing a meaningful reference for regional biodiversity conservation planning and producing a migrated method for biogeographic analysis in global biodiversity hotspots not just orchids. Besides, the results will supply crucial regional information for global biodiversity conservation.