The diffusion of the red ink in saline water is completely stochastic and highly unpredictable, and no differential model can precisely describe the process. This paper elucidates that the diffusion takes place in a molecule scale, therefore, the continuum assumption in fluid mechanics becomes totally invalid, and the two-scale fractal calculus has to be adopted to take into account the effects of the particles? size in the red ink and the properties of the saline solution including its concentration, water molecule?s size and distribution on the diffusion process. On the molecule?s scale, the diffusion becomes completely deterministic and predictable. An experiment is carefully designed and some phenomena, including optical observation and highly selective diffusion routine, are theoretically explained. This paper sheds light on modeling various contamination diffusion in air and water.

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Polymer bubbles are ubiquitously used for the fabrication of nanofibers by the bubble electrospinning. When a bubble is broken, the fragments tend to be wrinkled. The wrinkle angle plays an important in controlling the fiber morphology during the bubble electrospinning. This paper shows the maximal angle is about 49°, which is close to the experimental value of 50°. This maximal angle can be used for the optimal design of the nozzle in the bubble electrospinning for the fabrication of non-smooth nanofibers.

?Everything should be made as simple as possible?, as said by Albert Einstein, and thermal science is the best candidate to make a complex problem simple. This article introduces that the virus prevention is simple, only a cup of hot water is enough. Beyond its towering contribution to everyday life, thermal science is also an avid helper in each research frontier of science and technology, nothing is impossible. The new emerging two-scale thermal science is also elucidated.

As a new preparation process of nanofibers, electrospinning technology developed by bionic spider spinning can further improve the molecular structure and mechanical properties of nanofibers, and obtain nanofibers and base membrane products with better mechanical properties. The spider spinning needs minimal energy consumption though it has a very long liquid transport tube. Because spider silk has high mechanical properties and wide industrial applications, so a kind of new biomimetic electrospinning technology which harnessed a very long spiral-needle was proposed. Then poly(lactic acid)PLA/graphite oxide(GO)/dopamine (DA) nanofiber membrane was fabricated by the new biomimetic electrospinning technology. The results showed that compared with the pure PLA nanofiber membranes, the average pore size of PLA/GO porous nanofiber membranes decreased, the total number of pores increased, and the fracture strength and elongation at break increased. At the same time, the spun nanofibers were also more uniform. The pore size distribution of nanofiber was more dense after adding DA, and the fracture strength and elongation at break of nanofiber increased, while the nanofiber was also more even. After adding DA, the fracture strength was greatly increased and the elongation at break was similar to that of pure PLA nanofiber. The nanofiber membrane was obtained after oxidative polymerization of DA into poly(dopamine) (PDA), a layer of nanofiber membrane was attached to the surface of nanofiber. The performance of PLA/GO/PDA nanofiber membranes prepared based on PLA/GO/DA nanofiber membranes was superior to that of PLA/GO/PDA nanofiber membranes prepared based on PLA/GO nanofiber membranes, and its adsorption rate after 24 h was as high as 98.81%.