We examined environmental and anthropogenic factors drive range loss in large mammals, using presence data of Amur tigers opportunistically collected between 2000 and 2012, and anthropogenic and environmental variables to model the distribution of the Amur tiger in northeastern China. Our results suggested that population distribution models of different subregions showed different habitat factors determining tiger population distribution patterns. Where farmland cover was over 50 km2 per pixel (196 km2), distance was within 15 km to the railway in Changbaishan and road density (length per pixel) increased in Wandashan, the relative probability of Amur tiger occurrence exhibited monotonic avoidance responses; however, where distance was within 150 km of the Sino‐Russia border, the occurrence probability of Amur tiger was relatively high. We analyzed the avoidance or preference responses of Amur tiger distribution to elevation, snow depth and Viewshed. Furthermore, different subregional models detected a variety of spatial autocorrelation distances due to different population clustering patterns. We found that spatial models significantly improved model fits for non‐spatial models and made more robust habitat suitability predications than that of non‐spatial models. Consequently, these findings provide useful guidance for habitat conservation and management.
Ultrafine zirconium diboride (ZrB 2 ) powders have been synthesized by sol-gel process using zirconium oxychloride (ZrOCl 2 $8H 2 O), boric acid (H 3 BO 3 ) and phenolic resin as sources of zirconia, boron oxide and carbon, respectively. The effects of the reaction temperature, B/Zr ratio, holding time, and EtOH/H 2 O ratio on properties of the synthesized ZrB 2 powders were investigated. It was revealed that ultrafine (average crystallite size between 100 and 400 nm) ZrB 2 powders can be synthesized with the optimum processing parameters as follows: (i) the ratio of B/Zr is 4; (ii) the solvent is pure ethanol; (iii) the condition of carbothermal reduction heat treatment is at 1550°C for 20 min.
We consider a one-dimensional damped hyperbolic Timoshenko beam that is coupled with a heat equation. When its wave speeds are different, it is known that the Timoshenko beam that is coupled with a heat equation, under Cattaneo's law, does not have exponential stability. With two internal dampings being introduced, in this paper, we show that the system under Cattaneo's law is exponentially stable. We also show the exponential stability when the system is considered under Fourier's law.
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