We studied the foraging processes of wildebeest using an advection-diffusion equation. We equipped the model with data collected between 1999 and 2007 from the Serengeti ecosystem from 18 GPS-collared wildebeest. Resu...We studied the foraging processes of wildebeest using an advection-diffusion equation. We equipped the model with data collected between 1999 and 2007 from the Serengeti ecosystem from 18 GPS-collared wildebeest. Results analysis show that wildebeest foraging behavior can be explained by advective and diffusive parameters in a heterogeneous habitat like the Serengeti ecosystem.展开更多
The Jilin H5 chondrite, the largest known stony meteorite in the world, with its No.1 fragment weighing1770 kg. It contains submillimeter-to centimeter-sized FeNi metal particles/nodules. Our optical microscopic and e...The Jilin H5 chondrite, the largest known stony meteorite in the world, with its No.1 fragment weighing1770 kg. It contains submillimeter-to centimeter-sized FeNi metal particles/nodules. Our optical microscopic and electron microprobe analyses revealed that the formation of metal nodules in this meteorite is a complex and long-term process, The early stage is the thermal diffusion-caused migration and concentration of dispersed metallic material along fractures to form root-hair shaped metal grains during thermal metamorphism of this meteorite. The later two collision events experienced by this meteorite led to the further migration and aggregation of metallic material into the shock-produced cracks and openings to form largersized metal grains. The shock-produced shear movement and frictional heating occurred in this meteorite greatly enhanced the migration and aggregation of metallic material to form the large-sized nodules. It was revealed that the metal nodule formation process in the Jilin H5 chondrite might perform in the solid or subsolidus state, and neither melting of chondritic metal grains nor shock-induced vaporization of bulk chondrite material are related with this process.展开更多
A new mathematical system applicable to whatever Brownian problems where the Fickian diffusion equation (F-equation) is applicable was established. The F-equation, which is a parabolic type partial differential equati...A new mathematical system applicable to whatever Brownian problems where the Fickian diffusion equation (F-equation) is applicable was established. The F-equation, which is a parabolic type partial differential equation in the evolution equation, has ever been used for linear diffusion problems in the time-space (t, x, y, z). In the parabolic space (xt–0.5, yt–0.5, zt–0.5), the present study reveals that the F-equation becomes an ellipse type Poisson equation and furthermore the elegant analytical solutions are possible. Applying the new system to one-dimension nonlinear interdiffusion problems, the solutions were previously obtained as the analytical expressions. The obtained solutions were also elegant in accordance with the experimental results. In the present study, nonlinear diffusion problems are discussed in the two and three dimensional cases. The Brownian problem is widely relevant not only to material science but also to other various science fields. Hereafter, the new mathematical system will be thus extremely useful for the analysis of the Brownian problem in various science fields.展开更多
文摘We studied the foraging processes of wildebeest using an advection-diffusion equation. We equipped the model with data collected between 1999 and 2007 from the Serengeti ecosystem from 18 GPS-collared wildebeest. Results analysis show that wildebeest foraging behavior can be explained by advective and diffusive parameters in a heterogeneous habitat like the Serengeti ecosystem.
基金financially supported by the Science and Technology Planning Project of Guangdong Province,China, 2020B1212060055。
文摘The Jilin H5 chondrite, the largest known stony meteorite in the world, with its No.1 fragment weighing1770 kg. It contains submillimeter-to centimeter-sized FeNi metal particles/nodules. Our optical microscopic and electron microprobe analyses revealed that the formation of metal nodules in this meteorite is a complex and long-term process, The early stage is the thermal diffusion-caused migration and concentration of dispersed metallic material along fractures to form root-hair shaped metal grains during thermal metamorphism of this meteorite. The later two collision events experienced by this meteorite led to the further migration and aggregation of metallic material into the shock-produced cracks and openings to form largersized metal grains. The shock-produced shear movement and frictional heating occurred in this meteorite greatly enhanced the migration and aggregation of metallic material to form the large-sized nodules. It was revealed that the metal nodule formation process in the Jilin H5 chondrite might perform in the solid or subsolidus state, and neither melting of chondritic metal grains nor shock-induced vaporization of bulk chondrite material are related with this process.
文摘A new mathematical system applicable to whatever Brownian problems where the Fickian diffusion equation (F-equation) is applicable was established. The F-equation, which is a parabolic type partial differential equation in the evolution equation, has ever been used for linear diffusion problems in the time-space (t, x, y, z). In the parabolic space (xt–0.5, yt–0.5, zt–0.5), the present study reveals that the F-equation becomes an ellipse type Poisson equation and furthermore the elegant analytical solutions are possible. Applying the new system to one-dimension nonlinear interdiffusion problems, the solutions were previously obtained as the analytical expressions. The obtained solutions were also elegant in accordance with the experimental results. In the present study, nonlinear diffusion problems are discussed in the two and three dimensional cases. The Brownian problem is widely relevant not only to material science but also to other various science fields. Hereafter, the new mathematical system will be thus extremely useful for the analysis of the Brownian problem in various science fields.
